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1 A.N. Skanavi, A.M. Makhov HEATING Publishing house ASV Moscow

2 ^ / LBC UDC (075.8) CsV; Reviewers: Department of Heat and Gas Supply and Ventilation of the Moscow Institute of Public Utilities and Construction (head of the department, prof., Candidate of technical sciences E. M. Avdolimov) and head of the department of sanitary equipment of JSC "MOSPROEKT" Yu. A. Epshtein. ISBN Skanavn A.N., Makhov JI. M. Heating: Textbook for universities. - M .: Publishing house ASV, e .: ill. Federal Book Publishing Program of Russia The device and principle of operation are outlined different systems heating of buildings. Methods for calculating the thermal power of the heating system are presented. The design techniques, calculation methods and control methods are considered. modern systems central and local heating. The ways of improving the systems for saving thermal energy when heating buildings are analyzed. For higher students educational institutions, studying in the direction of "Construction", for the specialty "Heat and gas supply and ventilation". ISBN Skanavi A.N, Makhov L.M g Publishing house ASV g

3 CONTENTS FOREWORD 5 INTRODUCTION 7 SECTION 1. GENERAL INFORMATION ABOUT HEATING 17 CHAPTER 1. CHARACTERISTICS OF HEATING SYSTEMS Heating system Classification of heating systems Heat carriers in heating systems Main types of heating systems 25 CHAPTER 2. HEAT POWER OF THE SYSTEM HEATING SYSTEM LOSSES OF THE ROOM heat for heating the infiltrating outside air Accounting for other sources of heat input and costs Determination of the estimated thermal power of the heating system Specific thermal characteristic of a building and calculation of heat demand for heating according to aggregated indicators Annual heat consumption for heating buildings 49 SECTION 2. ELEMENTS OF HEATING SYSTEMS 52 CHAPTER 3. HEATING POINTS AND THEIR EQUIPMENT Heat supply of hot water heating system Substation of hot water heating system Heat generators for local hot water heating system Circulation pump hot water heating systems Mixing plant hot water heating systems Expansion tank hot water heating systems 78 CHAPTER 4. HEATING DEVICES Requirements for heating devices Classification heating appliances Description of heaters Selection and placement of heaters Heat transfer coefficient of the heater Density heat flow heater 112, 4.7. Thermal calculation of heating devices Thermal calculation of heating devices using a computer Regulation of heat transfer of heating devices 123 CHAPTER 5. HEAT PIPES OF HEATING SYSTEMS Classification and material of heat pipes Placement of heat pipes in the building Connection of heat pipes to heating devices Placement of shut-off and control valves Removing air from the heating system Insulation of heating pipes

4 SECTION 3. WATER HEATING SYSTEMS 162 CHAPTER 6. DESIGN OF WATER HEATING SYSTEMS..L Schemes of a pumped water heating system Heating system with natural circulation water Heating system of high-rise buildings Decentralized water-water heating system 178 CHAPTER 7. CALCULATION OF PRESSURE IN THE WATER HEATING SYSTEM Pressure change during the movement of water in pipes Pressure dynamics in the water heating system Natural circulation pressure Calculation of the natural circulation pressure in the water heating system Estimated circulation pressure in pumping system water heating 222 CHAPTER 8. HYDRAULIC CALCULATION OF WATER HEATING SYSTEMS Basic principles of hydraulic calculation of a water heating system Methods of hydraulic calculation of a water heating system Hydraulic calculation of a hot water heating system based on specific linear pressure loss Hydraulic calculation of a water heating system based on resistance characteristics and conductivity Features of hydraulic calculation of a heating system with devices from pipes 270 8.6. Features of the hydraulic calculation of a heating system with standpipes of a unified design Features hydraulic calculation heating systems with natural circulation of water 274 SECTION 4. STEAM, AIR AND PANEL-RADIANT HEATING SYSTEMS 279 CHAPTER 9. STEAM HEATING, 1. Steam heating system Schemes and design of a steam heating system Equipment for a steam heating system Systems of vacuum-steam and subatmospheric heating Selection of the initial steam pressure in the system Hydraulic calculation of steam pipelines low pressure Hydraulic calculation of steam lines high pressure Hydraulic calculation of condensate lines Calculation sequence of a steam heating system Use of flash steam Steam-water heating system

5 CHAPTER 10. AIR HEATING, Air heating system Air heating system diagrams Amount and temperature of air for heating Local air heating Heating units Calculation of the supply of air heated in a heating unit Apartment system air heating Recirculated air heaters Central air heating Particulars of calculation of central air heating ducts Mixing air-heat curtains 352 CHAPTER 11. RADIANT PANEL HEATING Radiant panel heating system Temperature situation in the room with radiant panel heating Heat exchange in the room with panel-radiant heating heating Design of heating panels, Description of concrete heating panels Heat carriers and schemes of a panel heating system, Area and surface temperature of heating panels Calculation of heat transfer from heating panels Features of designing a panel heating system 396 SECTION 5. LOCAL HEATING SYSTEMS 399 CHAPTER 12. OVEN HEATING Feature stove heating general description heating furnaces Classification of heating furnaces Design and calculation of fireboxes for heat-intensive furnaces Design and calculation of gas ducts for heat-intensive furnaces Construction of chimneys for furnaces Modern heat-intensive heating stoves Non-heat-consuming heating stoves Designing stove heating 425 CHAPTER 13. GAS HEATING General information Gas-fired heating stoves Gas-fired non-heat-consuming heaters, 4. Gas-air heat exchangers, 5. Gas-air radiant heating, 6. Gas radiant heating

6 CHAPTER 14. ELECTRIC HEATING General information Electric heaters Electric storage heating Electric heating with a heat pump Combined heating using electrical energy 460 SECTION 6. DESIGN OF HEATING SYSTEMS 465 CHAPTER 15. COMPARISON AND SELECTION OF HEATING SYSTEMS Technical indicators of heating systems Economic indicators of heating systems Areas of application of heating systems Conditions for choosing a heating system 477 CHAPTER 16. DEVELOPMENT OF THE HEATING SYSTEM The design process and composition of the heating project Standards and rules for heating design Heating design sequence Computer-assisted heating design Typical projects heating and their application 488 SECTION 7. INCREASING THE EFFICIENCY OF THE HEATING SYSTEM 490 CHAPTER 17. OPERATION MODE AND REGULATION OF THE HEATING SYSTEM Operating mode of the heating system Regulation of the heating system, Control of the operation of the heating system Features of the mode of operation and regulation of various heating systems 502 CHAPTER 18. IMPROVEMENT OF THE HEATING SYSTEM Reconstruction heating systems Two-pipe system water heating with increased heat resistance One pipe system hot water heating with thermosyphon heating devices Combined heating 517 SECTION 8. ENERGY SAVING IN HEATING SYSTEMS ... 521 CHAPTER 19. SAVING HEAT ON HEATING Reducing energy consumption for building heating Increasing the efficiency of building heating Heat pump installations for heating Heating interruptions in the automation of building automation Heating heating residential buildings

7 CHAPTER 20. USE OF NATURAL HEAT IN HEATING SYSTEMS: Systems low temperature heating: Solar Heating Systems Systems geothermal heating"Heating systems using waste heat REFERENCES 1 SUBJECT INDEX i Educational publication Skanavi Alexander Nikolaevich Makhov Leonid Mikhailovich HEATING

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For students of higher educational institutions studying in the direction of "Construction" for the specialty 290700 "Heat and gas supply and ventilation" Heating BBK 38.762 UDC 697.1 (075.8) 2 .................................................. .................................................. .......... 7 IN E D E N E N .................................. .................................................. .......................................... ... ... .. 9 SECTION 1. GENERAL INFORMATION ABOUT HEATING ........................................ ..................... 18 CHAPTER 1. CHARACTERISTICS OF HEATING SYSTEMS ...................... ......................... 18 1.1. Heating system ................................................ .................................................. . 18 1.2. Classification of heating systems ............................................... ........................... 20 1.3. Heat carriers in heating systems .............................................. ...................... 22 1.4. The main types of heating systems .............................................. ............................ 2b CONTROL TASKS AND EXERCISES ................. .......................................... 29 CHAPTER 2. HEATING CAPACITY ................................... 30 2.1. Heat balance of the room ............................................... .................................... 30 2.2. Heat loss through room fences ............................................. ........ 31 2.3. Heat losses for heating the infiltrating outside air ........... 37 2.4. Accounting for other sources of heat input and costs ..................................... 41 2.5. Determination of the estimated thermal power of the heating system ...................... 42 2.b. Specific thermal characteristics of the building and calculation of heat demand for heating according to aggregated indicators. .................................................. ...................... 43 2.7. [One heat consumption for heating buildings ........................................... ......... 4b CONTROL TASKS AND EXERCISES .................................... ....................... 48 SECTION 2. ELEMENTS OF HEATING SYSTEMS .................... ............................................ 49 CHAPTER 3. THERMAL POINTS AND THEM. EQUIPMENT ........................................... 49 H.1. Heat supply of the water heating system .............................................. ....... 49 3.2. Substation of hot water heating system ............................................. ......... 51 3.3. Heat generators for the local hot water heating system .............................. 5b 3.4. Circulation pump of the water heating system ......................................... b1 3.5. Mixing unit for water heating system ........................................ b8 3.b. Expansion tank for hot water heating system ............................................. 73 CONTROL TASKS AND EXERCISES ............................................. .............. 79 r LAVA 4. HEATING DEVICES ............................. .............................................. 80 4.1. Requirements for heating devices ...................................... 80 4.2. Classification of heaters ............................................... ................ 82 4.3. Description of heaters ............................................... .......................... 84 4.4. Selection and placement of heating devices ............................................. ......... 90 4.5. Heat transfer coefficient of the heating device ......................................... 9b 4.b. Heat flux density of the heating device ........................................ 105 4.7. Thermal calculation of heating devices .............................................. ............. 107 4.8. Thermal calculation of heating devices using a computer ............................. 112 4.9. Regulation of heat transfer of heating devices .................................... 115 CONTROL TASKS AND EXERCISES ... .................................................. .. 117 r CHAPTER 5. HEATING PIPES FOR HEATING SYSTEMS ......................................... ........ 118 5.1. Classification and material of heat pipes .............................................. ........... 118 5.2. Placement of heat pipes in the building. .................................................. ................ 121 5.3. Connection of heat pipelines to heating devices ............................... 128 5.4. Placement of shut-off control valves .............................................. ..... 132 5.5. Removing air from the heating system ............................................. ................ 141 5.b. Insulation of heat pipes ................................................ ....................................... 148 CONTROL TASKS AND EXERCISES ...... .................................................. . 150 SECTION 3. WATER HEATING SYSTEMS .......................................... .................. 151 r CHAPTER b. DESIGN OF WATER HEATING SYSTEMS ................... 151 b.1. Diagrams of the HacocHoro hot water heating system ............................................. ..... 151 3 6.2. Heating system with natural water circulation ...................................... 159 6.3. Water heating system for high-rise buildings ............................................. ..... 163 6.4. Decentralized water-water heating system .................................... 166 CONTROL TASKS AND EXERCISES .... .................................................. ... 168 CHAPTER 7. CALCULATION OF PRESSURE IN THE WATER HEATING SYSTEM ............... 168 7.1. Pressure change during the movement of water in pipes ........................................... .. 169 7.2. Pressure dynamics in the water heating system ............................................ 172 7.3. Natural circulating pressure ............................................... .............. 193 7.4. Calculation of eCTecTBeHHoro circulating pressure in a hot water heating system .......................................... .................................................. .................................. .............. 196 7.5 ... Estimated circulating pressure in the pumping system of hot water heating .......................................... .................................................. .................................. .............. 206 CONTROL TASKS AND EXERCISES ............................................... .......... 21 ABOUT CHAPTER 8. HYDRAULIC CALCULATION OF WATER HEATING SYSTEMS ...... 211 8.1. The main provisions of the hydraulic calculation of the water-heating system211 8.2. Methods of hydraulic calculation of a water heating system ..................... 214 8.3. Hydraulic calculation of the hot water heating system based on the specific linear pressure loss. .................................................. .................................................. ........... 217 8.4. hydraulic calculation of the water-heating system according to the characteristics of resistance and conductivity ........................................ ............................................ 238 8.5. Features of the hydraulic calculation of a heating system with devices from pipes ......................................... .................................................. ................................... .............. 253 8.6. Features of the hydraulic calculation of a heating system with standpipes of a unified design ......................................... ............................................. 254 8.7. Features of the hydraulic calculation of a heating system with natural water circulation ......................................... .................................................. ................. 256 CONTROL TASKS AND EXERCISES ............................ ............................. 259 SECTION 4. STEAM, AIR AND PANEL RADIANT SYSTEMS. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .. 260 r LOVE 9. STEAMING. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .. 260 9.1. Steam heating system ............................................... .................................. 260 9.2. Schemes and structure of the steam heating system ............................................ . 261 9.3. Steam heating system equipment .............................................. ......... 267 9.4. Systems of vacuum, steam and subatmospheric heating ................................. 274 9.5. Selection of the initial steam pressure in the system. .................................................. ..... 275 9.6. hydraulic calculation of low pressure steam pipelines .................................. 276 9.7. hydraulic calculation of high pressure steam pipelines ................................. 278 9.8. hydraulic calculation of condensate lines ............................................... ....... 280 9.9. The sequence of calculating the steam heating system ............................... 283 9.10. Use of steam to reboil. .................................................. ... 287 9.11. Steam-water heating system ............................................... ........................ 289 CONTROL TASKS AND EXERCISES ..................... .................................... 291 r LAV A 1 o. SHOOTING ....................................... .................................. 292 10.1. Air heating system ............................................... ........................... 292 10.2. Air heating system diagrams .............................................. ............... 293 10.3. Air quantity and temperature for heating ........................................... 296 10.4. Local air heating ............................................... ............................ 299 10.5. Heating units ................................................ ....................................... 299 10.6. Calculation of air supply, HarpeToro in heating arperaTe ............................ 302 1 0.7. Apartment air heating system .............................................. ........ 307 10.8. Recirculating air heaters ................................................ ............ 308 10.9. Central air heating ............................................... ..................... 317 4 10.10. Features of the calculation of air ducts for central air heating. 323 10.11. Mixing air-heating curtains .............................................. ........ 328 CONTROL TASKS AND EXERCISES ..................................... .................... 333 [LAVA 11. PANEL RADIANT HEATING ...................... ................................ 333 11.1. Radiant panel heating system .............................................. .............. 333 11.2. Temperature situation in the room with radiant panel heating .......................................... .................................................. ................................................ 336 11.3 ... Heat exchange in a room with radiant panel heating ........................ 340 11.4. Heating panels design ............................................... ................... 345 11.5. Description of concrete heating panels .............................................. ........ 348 11.6. Heat carriers and schemes of the panel heating system ................................. 353 11.7. Area and surface temperature of heating panels. ........................ 355 11.8. Calculation of heat transfer of heating panels .............................................. ..... 362 11.9. Features of designing a panel heating system ....................... 367 CONTROL TASKS AND EXERCISES ................. ........................................ 369 SECTION 5. LOCAL SYSTEMS [ABOUT HEATING. .................................................. ........ 370 [LOVE 12. STEERING ........................... .................................................. ..... 3 7 M 12.1. Furnace heating characteristics ............................................... .................... 370 12.2. General description of heating stoves .............................................. .................. 372 12.3. Heating stove classification ............................................... ................... 373 12.4. Design and calculation of fireboxes for heat-intensive stoves ............................ 376 12.5. Design and calculation of ducts of heat-intensive furnaces ................................. 379 12.6. Construction of chimneys for ovens ............................................. .......... 383 12.7. Modern heat-consuming heating furnaces .............................................. .... 384 12.8. Not heat-consuming heating stoves .............................................. ....................... 391 12.9. Designing stove heating ............................................... .................... 393 CONTROL TASKS AND EXERCISES ......................... ................................ 398 [LAVA 13. [AZO HEATING ........ .................................................. ...................... 399 13.1. General information ................................................ .................................................. .. 399 13.2. [basic heating ovens .............................................. .................................. 399 13.4. [gas-air heat exchangers ............................................... ......................... 402 13.5. [gas air radiant heating .............................................. ..................... 403 13.6. [Basic radiant heating .............................................. .................................. 405 CONTROL TASKS AND EXERCISES ........... .............................................. 407 [LAVA 14 . ELECTRIC HEATING ............................................... .................. 407 14.1. General information. .................................................. ................................................. 407 14.2. Electric heaters. .................................................. ........... 409 14.3. Electric storage heating ............................................... ...... 416 14.4. Electric heating with a heat pump ................................. 421 14.5. Combined heating using electric energy ... 426 CHECKS AND EXERCISES ................................. ........................ 429 SECTION 6. DESIGN OF HEATING SYSTEMS ................... ............................. 430 [CHAPTER 15. COMPARISON AND SELECTION OF HEATING SYSTEMS ........... ........................... 430 15.1. Technical indicators of heating systems. .................................................. .... 430 15.2. Economic indicators of heating systems .............................................. .... 432 15.3. Scopes of heating systems .............................................. ............... 436 15.4. Conditions for choosing a heating system .............................................. .................... 440 CONTROL TASKS AND EXERCISES ......................... ................................ 442 [LAVA 16. DEVELOPMENT OF THE HEATING SYSTEM .......... .......................................... 442 16.1. The design process and composition of the heating project ..................................... 442 16.2. Norms and rules for the design of heating ............................................. ...... 444 16.3. Heating design sequence .............................................. 444 5 1b.4. Heating design using a computer ............................................. ...... 447 1b.5. Typical heating projects and their application ............................................ ..... 449 CONTROL TASKS AND EXERCISES ........................................ ................. 450 SECTION 7. IMPROVING THE EFFICIENCY OF THE HEATING SYSTEM .................. 451 r CHAPTER 17. OPERATION AND REGULATION OF THE HEATING SYSTEM ... 451 17.1. Heating system operating mode .............................................. ....................... 451 17.2. Heating system regulation ............................................... ...................... 455 17.3. Heating system operation control .............................................. ............. 459 17.4. Features of the operating mode and regulation of various heating systems. .................................................. .................................................. ......................... .............. 4b1 CONTROL TASKS AND EXERCISES ...... .................................................. . 4bb rCHAPTER 18. IMPROVEMENT OF THE HEATING SYSTEM .............................. 4b7 18.1. Reconstruction of the heating system ............................................... ..................... 4b7 18.2. Two-pipe water heating system with increased thermal stability ........................................... .................................................. ..................... ... 4b9 18.3. One-pipe water heating system with thermosyphon heating devices .......................................... .................................................. .............................. 472 18.4. Combined heating ................................................ .............................. 474 CONTROL TASKS AND EXERCISES ............... .......................................... 47b SECTION 8. ENERGY SAVING IN HEATING SYSTEMS .................................. 477 r CHAPTER 19. SAVING HEAT FOR HEATING ........ ........................................ 477 19.1. Reduction of energy consumption for heating the building ......................................... 477 19.2. Improving the efficiency of building heating .............................................. ... 481 19.3. Heat pump installations for heating .............................................. ............ 482 19.4. Saving heat when automating the operation of the heating system ............... 488 19.5. Intermittent heating of buildings ............................................... ........................... 489 19.b. Heating rationing for residential buildings .............................................. ............. 494 CONTROL TASKS AND EXERCISES ................................ ......................... 49b rCHAPTER 20. USE OF NATURAL HEAT IN HEATING SYSTEMS. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .. 497 20.1. Low temperature heating systems. .................................................. ..... 497 20.2. Solar heating systems ............................................... ........................... 500 20.3. Reothermal heating systems. .................................................. ............... 50b 20.4. Heating systems using waste heat ............................... 508 CHECKS AND EXERCISES ........ ................................................. 509 Appendix 1 Indicators for calculating the fireboxes of heating stoves ................... 51 О Appendix 2 Indicators for calculating the ducts of heating stoves ............. ........... 511 REFERENCES .................................... .................................................. .............. 512 b FOREWORD The discipline "Heating" is one of the most important disciplines in the training of specialists in heat and gas supply and ventilation. Its study provides for the acquisition of fundamental knowledge on the structures, principles of operation and characteristic properties of various heating systems, on the methods of their calculation and design techniques, methods of regulation and management, and promising ways of developing this branch of the construction industry. To master theoretical, scientific, technical and practical knowledge related to the discipline "Heating", a deep understanding and assimilation of physical processes and phenomena occurring both in heated buildings and directly in heating systems and their individual elements... These include processes associated with the thermal regime of a building, movement of water, steam, and air through pipes and channels, phenomena of their heating and cooling, changes in temperature, density, volume, phase transformations, as well as regulation of thermal and hydraulic processes. The discipline "Heating" is based on the provisions of a number of theoretical and applied disciplines. These include: physics, chemistry, thermodynamics and heat and mass transfer, hydraulics and aerodynamics, electrical engineering. The choice of the heating method depends to a large extent on the features of the constructive and ap-hitectural planning decisions of the building, on the thermotechnical properties of the ero fences, i.e. issues that are studied in general construction disciplines and in the discipline "Building thermal physics". The discipline "Heating" is closely related to the special technical disciplines that make up the specialty "Heat and gas supply and ventilation": "Theoretical foundations of creating a microclimate in a room", "Heat-generating installations", "Pumps, fans and compressors", "Heat supply", "Ventilation", "Air conditioning and refrigeration supply", "Gas supply", "Automation and control of heat and gas supply and ventilation processes". It includes in an abbreviated form many related elements of the listed disciplines, as well as issues of economics, use of computing technology, production installation works detailed in the relevant COOT courses. The previous textbook "Heating", developed by a team of authors MOCKoBcKoro Engineering Construction Institute. V.V. Kuibyshev (MISS), was published in 1991. Over the last decade of the revival of the market economy in Russia, dramatic changes have taken place, including in the construction industry. The volume of construction has noticeably increased, the ratio in the use of domestic and foreign equipment has changed. New types of heating equipment and technologies have appeared, often without analogues in Russia. All this should have been reflected in the new edition of the textbook. This textbook was developed at the Department of Heating and Ventilation MOCKoBcKorocy of the University of Civil Engineering (MrCY) in accordance with the current standard program based on a course of lectures delivered by prof. A.N. Skanavi since 1958 Without changing the basic theoretical and methodological foundations of the course, taking into account modern technologies in heating engineering and technology since 1996. this course is taught at the department by prof. L.M. Makhov. 7 As in previous editions of the textbook, the authors did not consider it necessary to give detailed descriptions continuously modernizing equipment, common reference data, as well as calculation tables, graphs, nomographs. The exception is OT practical specific information required for examples and explanations of structures and physical phenomena. Separate sections contain practical examples of the calculation of heating systems and their equipment. After each chapter, control tasks and exercises are given to test the knowledge gained. They MorYT can be used in scientific and educational research work of students, as well as during the state exam in the specialty. this textbook is based on the material prepared by prof. A.N. Scanavi for the previous edition. The textbook also used the materials of the sections from the previous edition, compiled by: Hon. worker of science and technology of the RSFSR, prof., doctor of technical sciences. V.N. Boslovsky (rl. 2, 19), prof., Ph.D. E.r. Malyavina (rl. 14), Ph.D. I.V. Meshchaninov (rl. 13), Ph.D. c.r. Bulkin (rl. 20). The authors are grateful for their help in compiling the textbook, prof., Doctor of Technical Sciences. y.ya. Kuvshinov, as well as Ing. A.A. Serenko for technical assistance in ero design. The authors express their deep gratitude to the reviewers of the Department of Heat and Gas Supply and Ventilation MOCKoBcKoro of the Institute of Public Utilities and Construction (head of the department, prof., Candidate of technical sciences E.M. Avdolimov) and Ing. Yu.A. Epstein (OJSC "MOSPROEKT") for valuable advice and remarks made during the review of the manuscript of the textbook. 8 INTRODUCTION Energy consumption in Russia, as well as throughout the world, is steadily increasing and, first of all, to provide heat to the engineering systems of buildings and structures. It is known that more than one third of all the organic fuel produced in our country is consumed for the supply of civil and industrial buildings. Over the past decade, in the course of economic and social reforms in Russia, the structure of the country's fuel and energy complex has radically changed. The use of solid fuels in heat power engineering is noticeably decreasing in favor of cheaper and more environmentally friendly natural gas. On the other hand, there is a constant increase in the cost of all types of fuel. This is due to both the transition to a market economy and the complication of fuel extraction during the development of deep deposits in new remote regions of Russia. In this regard, the solution of the problems of economical consumption of heat at all stages from its generation to the consumer is becoming more and more urgent and significant on a national scale. The main heat costs for communal household needs in buildings (heating, ventilation, air conditioning, hot water supply) are heating costs. This is explained by the operating conditions of buildings during the heating zone in most of the territory of Russia, when the heat loss through their external enclosing structures significantly exceeds the internal heat release. To maintain the required temperature conditions, buildings have to be equipped with heating installations or systems. Thus, heating is called artificial, with the help of a special YCTaHOB ki or system, heating the premises of a building to compensate for heat losses and maintain temperature parameters in them at a level determined by the conditions of thermal comfort for people in the room or the requirements of technological processes taking place in production premises. ... Heating is an industry construction equipment... The installation of a stationary heating system is carried out during the construction of the building, its elements during the design are linked to building structures and are combined with the layout and interior of the premises. At the same time, heating is one of the types of technological equipment. Parameters of work heating system must take into account the thermal and physical characteristics of the structural elements of the building and be coordinated with the operation of other engineering systems, first of all, with the operating parameters of the ventilation and air conditioning system. The operation of heating is characterized by a certain periodicity during the year and variability of the used capacity of the installation, which depends, first of all, on the meteorological conditions in the construction area. With a decrease in the outdoor temperature Horo of the air and an increase in the wind, it should increase, and with an increase in the temperature Ha of the outdoor air, the effect of solar radiation, the heat transfer from OTO heating installations to the premises should decrease, i.e. the heat transfer process must be constantly regulated. Changes in external influences are combined with uneven heat gains from internal production and household sources, which also necessitates regulation of the operation of heating installations. To create and maintain thermal comfort in the premises of buildings, technically perfect and reliable heating installations... And the more severe the climate of MeCTHO 9 and the higher the requirements for ensuring favorable thermal conditions in the building, the more powerful and flexible these installations must be. The climate of most of our country is characterized by severe winters, similar only to winters in the northwestern provinces of Canada and Alaska. Table 1 compares the climatic conditions in January (the coldest month of the year) in Moscow with the conditions in large cities of the CeBepHoro hemisphere of the Earth. It can be seen that the average January temperature in them is much higher than in Moscow, and is typical only for the southernmost species of Russia, which are distinguished by mild and short winters. Table 1. Average temperature of the outside air in large cities of the CeBepHoro hemisphere during the coldest month of the month ropon r eorraphic Average temperature latitude. January, Os Moscow 550 50 ".. [o 2, New York 400 40" o 8,. BerJ1IN 520 30 ". & O t3 Paris 480 50 J" 2) 3 LONDON 51 o 30 "+4 O Heating of buildings begins with a steady (within 5 days) decrease in the average daily temperature of the outside air to 8 oC and below, and ends at stable increase in the outside air temperature up to 8 o C. The period of heating of buildings during the year is called the heating season.< 8 ос. Для характеристики изменения температуры наружноrо воздуха tH в течение отопитель Horo сезона рассмотрим rрафик (рис. 1) продолжительности стояния z одинаковой cpeДHe суточной температуры на примере Москвы, rде продолжительность отопительноrо сезона ZO с составляет 7 мес (214 сут). Как видно, наибольшая продолжительность стояния TeM пературы в Москве относится к average temperature heating season (3.1 ops). This pattern is typical for most regions of the country. The duration of the heating season is short only in the extreme south (3-4 months), and in most of Russia it is 6-8 months, reaching 9 (in Arkhangelsk, Murmansk and other regions) and even up to 11-12 months (in the Madan region and Yakutia) ... 10 Z. "H t5JO 500 1300 iOOO, = 214 C) T a + 8 h. 1 1 2 3 t c + 1 о CI 10.2 · 20 ..28..30 ... 32 42 Fig. 1. The duration of standing of the same average daily temperature of the outside air for heating season In Moscow, the severity or mildness of winter is more fully expressed not by the duration of heating of buildings, but by the value of -radio per day by multiplying the number of days of heating action on the difference between the internal and external temperatures averaged for this period of time. In Moscow, this number of radios per day is 4600, and, for comparison, in the north of the Krasnoyarsk Territory it reaches 12800. This indicates a wide variety of local climatic conditions on the territory of Russia, where almost all buildings must have one or another heating installation. The state of the air environment in rooms during cold weather is determined by the action of not only heating, but also ventilation. Heating and ventilation are designed to maintain, in addition to the required temperature environment, certain humidity, mobility, pressure, gas composition and air purity. In many civil and industrial buildings heating and ventilation are inseparable. Together they create the required sanitary and sanitary conditions, which helps to reduce the number of human diseases, improve their well-being, and increase labor productivity and product quality. in the structures of the agroindustrial complex by means of heating and ventilation climatic conditions ensuring the maximum productivity of animals, birds and plants, the safety of agricultural products. Buildings and their working premises, industrial products require for the cBoero HOp a minimum of appropriate temperature conditions... If they are violated, the service life of the enclosing structures is significantly reduced. Many technological processes for the production and storage of a number of products, products and substances (precision electronics, textiles, products of the chemical and glass industry, flour and paper, etc.) require CTpororo to maintain the specified temperature conditions in the premises. 11 The long process of transition from a fire and a hearth for heating a dwelling to modern designs of heating devices was accompanied by their constant improvement and an increase in the efficiency of fuel combustion methods. Russian heating technology originates from the culture of those ancient tribes, which inhabited a significant part of the southern regions of our Motherland even in the Neolithic era of the KaMeHoro century. Archaeologists have discovered thousands of constructions of the KaMeHHoro century in the form of dugout caves, equipped with stoves, hollowed out in rpYHTe at the floor level and half outward with their rimless vault and mouth inside the dugout. These ovens were fired "black", i.e. with smoke removal directly into the dugout and then outside through the opening, which simultaneously served as an entrance. It was such a lino-bit ("chicken") stove that for many centuries was practically the only heating and food-cooking device of the ancient Russian dwelling. in Russia only in the XY XYI centuries. stoves in living quarters were supplemented with pipes and became known as "white" or "Russian". Air heating appeared. It is known that in the XU century. such heating was installed in the Kremlin's new MOCKoBcKoro chamber, and then, under the name "Russian system", was used in Germany and Austria to heat large buildings. Purely heating stoves with chimneys dating back to the 18th century. were considered a subject of special luxury and were installed only in large palace buildings. Domestic production of highly artistic tiles for exterior decoration furnaces existed in Russia as early as the XI XII centuries. The furnace business received significant development in the era of Peter 1, who, with his personal decrees 1698 1725 rr. was the first to introduce in Russia the basic norms of stove building, which strictly prohibited the construction of black huts with chimney stoves in St. Petersburg, Moscow and other large cities. Peter I personally took part in the construction of demonstration residential buildings in St. Petersburg (1711) and Moscow (1722), "so that people could know how to make ceilings with linen and stoves." He also introduced the obligatory cleaning of chimneys from soot in all cities of Russia. The great merit of Peter I should be considered the ero measures for the development of factory production of all basic materials and products for stove heating. Large factories for the production of bricks, tiles and stove appliances are being built near Moscow, St. Petersburg and other towns, and all materials for stove-building are being traded. The Tula plant, the largest in Russia, becomes the main supplier of iron and cast iron room stoves and metal stove appliances. A major work summarizing stove heating, "Theoretical Foundations of Stove Engineering" was written by I.I. Sviyazev in 1867. in Europe, fireplaces were widely used for space heating. BEFORE XVII century fireplaces were arranged in the form of large niches, equipped with umbrellas, under which smoke collected, then leaving chimney... Sometimes these niches were made in the thickness of the wall itself. In any case, the rooms were heated only by radiation. Since 1624 r. Attempts begin to utilize the heat of the combustion products to heat the air in the room. The first to suggest such a device was the French architect Savo, who arranged a fireplace in the Louvre, under the KOToporo, raised above the floor, and the back wall of the OT 12 is divided from the wall. Thus, a channel was formed, into which air enters from the floor of the room and, rising along the back wall, exits into two side holes in the upper part of the fireplace. Another type of heating in Europe and Russia was air-to-air. Examples of ero devices were encountered as early as the 13th century. Devices for central air-to-air underfloor heating were discovered during excavations on the territory of Khakassia in Siberia, China and Greece. The theoretical foundations for the design and calculation of these systems were given by our compatriot N.A. Lvov ("Russian Pirostatics", 1795 and 1799 rr.). In 1835 r. General N. Amosov designed and then with great success applied the original "pneumatic ovens" for air heating, and the subsequent theoretical and practical work of our engineers (Fullon and Shchedrin, Sviyazev, Dershau, Cherkasov, Voinitsko, Bykov, Lukashevich, etc.) contributed to the widespread dissemination of this prototype of modern air heating technology. Various methods of space heating are difficult to attribute to certain stages in the history of social development. At the same time, there were YCT heating units standing both at the lowest and at a sufficient high levels... The simplest and most ancient method of heating by burning solid fuels inside a building was combined with central water or air heating systems. So, in r. Ephesus, founded in the 10th century. BC. On the territory of modern Turkey, already at that time, heating pipes were used, into which hot water was supplied from closed boilers located in the basements of houses. The Hupocaustum air heating system ("littered from below"), created in the Roman Empire, was described in detail by Vitruvius (end of the 1st century BC). Outside air was heated in underfloor ducts, preliminarily pierced with hot smoke gases, and entered the heated rooms. A similar kind of heating device by heating floors was used in northern China, where walls were placed in the underground instead of pillars, forming horizontal chimneys. Similar heating systems were often used in Russian churches and large buildings. According to the same principle, in the Middle Ages, the premises of locks in IAC ca - [- 00 7 6 1 parosb () PI1IK 8 6 3 Fig. 1.6. Steam heating system diagrams: a closed circuit; b open circuit; 1 steam boiler with steam collector; 2 steam line (T7); 3 heater; 4 and 5 gravity and pressure condensate pipelines (T8); 6 air outlet pipe; 7 KOHдeH satin tank; 8 condensate pump; 9 steam distribution header in a closed system, condensate is continuously supplied to the boiler under the influence of a pressure difference, expressed by a column of condensate with a height h (see Fig. 1.6, a) and steam pressure pp in the boiler steam collector. In this regard, the heating devices must be located DOCTa exactly high above the steam collector (depending on the steam pressure in it). in an open-loop steam heating system, condensate from caMOTecom heating devices continuously enters the condensate tank and, as it accumulates, is periodically pumped into the boiler by a condensate pump. In such a system, the location of the tank should ensure that condensate flows from the lower heater into the tank, and the steam pressure in the boiler is overcome by the pump pressure. Depending on the steam pressure, steam heating systems are subdivided into subatomic, vacuum ... steam, low and high pressures (Table 1.2). Table 1.2. Parameters of saturated steam in steam heating systems I 1 MLa KDJKJ Kr Subatmospheric<0,10 <100 >2260 Vacuu m. Steam<О, 1 1 <100 > 2260 N low pressure O J 1 O 5 o] 7 1 oo 115 2260 ..... 2220 High pressure O) I 7 .. 0.27 115 130 2220 -2] 75 Maximum vapor pressure is limited by the permissible limit of long-term maintenance of temperature surfaces of heating devices and pipes in rooms (an excess pressure of 0.17 MPa corresponds to a steam temperature of approximately 130 ° C). in subatmospheric and vacuum steam heating systems, the pressure in the devices is less than atmospheric and the steam temperature is below 100 ° C. In these systems, it is possible to regulate the temperature of the steam by changing the value of the vacuum (rarefaction). Heat pipelines of steam heating systems are divided into steam pipelines, through which steam moves, and condensate pipelines for condensate drainage. Steam moves along steam pipelines under pressure рп in the boiler steam collector (see Fig. 1.6, a) or in the steam distribution manifold (see Fig. 1.6, b) to the heating devices. Condensate lines (see fig. 1.6) MorYT be gravity and pressure. Gravity pipes are laid below the heating devices with a slope Towards the direction of movement of KOH denat. In the pressure pipes, the condensate moves under the influence of the pressure difference created by the pump or the residual steam pressure in the devices. in steam heating systems, two-pipe risers are predominantly used, but one-pipe risers are also used MorYT. With air heating, the circulating heated air is cooled, transferring heat when mixed with the air of the heated rooms and other through their BHYTpeH enclosure. The cooled air is returned to the heater. Air heating systems, according to the method of creating air circulation, are divided into systems with natural circulation (gravitational) and with mechanical induction of air movement by means of a fan. The gravitational system uses the difference in density between the HarpeToro and the ambient air heating system. As in a water vertical gravitational system, at different air densities in the vertical parts, natural air movement occurs in the system. When using a fan, a forced air movement is created in the system. The air used in heating systems is heated to a temperature usually not exceeding 60 ° C in special heat exchangers, air heaters. Heaters MorYT be heated with water, steam, electricity or hot gases. In this case, the air heating system is respectively called water-air, steam-air, electric-air or air-air. Air heating can be local (fig. 1.7, a) or central (Fig. 1.7, b). a) b) 1 11. 11 H: I J I II..t 1! IIII. \ (HI (J (111. "1 2 lr 2 ----...-.------- ... - __--- .. 3 --- - - - - - - --- h t i t H \ 5 4 Fig. 1.7. Schemes of the air heating system: a local system; b central system; 1 heating arperaT; 2 heated room (rooms in Fig. b); 3 work ( served) area of ​​the room; 4 return air duct; 5 fan; 6 heat exchanger (air heater); 7 supply air duct In the local system, the air is heated in a heating system with a heat exchanger (air heater or other heating device) located in the heated room. (air heater) is placed in a separate room (chamber) .Air at temperature tB is supplied to the heater through a return (recirculated) air duct. during the heating season in the main regions of the territory of Russia. Appreciate the severity (the number of days per day) of winter in your town in comparison with the weather in B r. Verkhoyansk. 3. Draw a schematic diagram of the heat supply to your residential (educational) building. 4. Calculate the comparative reserve of thermal energy for heating the premises in 1 Kr of the three main heat carriers. 5. Describe the heating system of your dwelling building on the basis of classification criteria. 29 6. What explains the spread of hot water heating in civil and air heating in industrial buildings? 7. Draw a riser and a horizontal branch of a bifilar water heating system. 8. Determine how much the heat transfer of the heating device to the room will decrease (temperature 20 ° C) if the absolute pressure of saturated steam in the device in one case is 0.15, and in the other 0.05 MPa, i.e. will decrease by 3 times. r LAVA 2. THERMAL POWER OF THE HEATING SYSTEM 2.1. Thermal balance of the room The heating system is designed to create a temperature environment in the premises of a building that is suitable for a person's comfort or meets the requirements of the Tex-nological process. The heat released by the human body should be given to the environment and in such an amount that a person who is in the process of performing KaKoro or an activity does not feel cold or overheated. Along with the costs of evaporation from the surface of the skin and lungs, heat is released from the surface of the body through convection and radiation. The intensity of heat transfer by convection is mainly determined by the temperature and mobility of the surrounding air, and by means of radiation by the temperature of the surfaces of the enclosures facing the inside of the room. The temperature situation in the room depends on the thermal power of the heating system, as well as on the location of the heating devices, the thermophysical properties of external and internal fences, the intensity of other sources of heat input and loss. In cold weather, the room mainly loses heat through the outer fences and, to some extent, through the inner fences that separate this room from adjacent ones with a lower air temperature. In addition to Toro, heat is spent on heating the outside air, which enters the room through the non-density of fences, as well as materials, vehicles, products, clothing, which are cold outside into the room. The ventilation system can supply air with a lower temperature in relation to the room temperature. Technological processes in the premises of MorYT industrial buildings are associated with the evaporation of liquids and other processes accompanied by the consumption of heat. In the steady state (stationary) mode, the losses are equal to the heat gain. Heat enters the premises from people, technological and household equipment, sources of artificial lighting, from heated materials, products, as a result of exposure of the building to solar radiation. Technological processes associated with the release of heat (moisture condensation, chemical reactions, etc.) are carried out in the production premises of MorYT. It is necessary to take into account all the listed components of losses and heat input when calculating the heat balance of the premises of a building and determining the deficit or excess of heat. The presence of a heat deficit Q indicates the need for a device in the room for heating. Excess heat is usually assimilated by ventilation. To determine 30 thermal power of the heating system, QOT compiles the balance of heat consumption for pac even conditions of cold water period in the form of QOT ": = 6.Q == Qorp + QI (8 tfT): t Qt (life)" (2.1) rde Corp. heat loss through external fences; QH (BeHT) heat consumption for Harpement of the outside air entering the room; QT (6bIT) technological or household emissions or heat consumption. The balance is compiled for the conditions when the largest heat deficit for a given supply coefficient occurs. For civil (usually, for residential) buildings, regular heat gains into the premises from people, lighting, and other household sources are taken into account. In industrial buildings, the period of the technological cycle with the lowest heat release is taken into account (possible maximum heat release is taken into account when calculating ventilation). The heat balance is calculated for stationary conditions. The non-stationarity of thermal processes occurring during space heating is taken into account by special calculations based on the theory of thermal stability. 2.2. Heat losses through the fences of the room The greatest heat losses through the ith fencing of the room Qi, W, are determined by the formula Qi ;;;;;; (Ai J. I) (1p texJ ni (1 L i)) (2.2) 2 -de A i fencing area, m; Ro i reduced resistance to heat transfer fencing 2 "denia, m.oC / W; tp design temperature of the room, oC; t ext design temperature outside the fence, oo; P; coefficient taking into account the actual decrease in pac of an even temperature difference (tpt ext) for fences, which separate the heated room from the unheated one (basement, attic, etc.); Рl coefficient, which takes into account additional heat losses through the fences.The design temperature of the room tp is usually set equal to the design air temperature in the room tB, os, taking into account its possible increase in height in rooms with a hundredth more than 4 m. The temperature tB is taken depending on the purpose of the room according to SNiP, corresponding to the purpose of the heated building. cold room when calculating losses Te rafts black Without internal fencing. The value of the greatest heat loss through the outer fences will correspond to the given coefficient of the provision of internal conditions in the room K about, taking into account KOToporo, and the value text == tH is chosen. In COOTBeTCT, in accordance with the current norms of heat loss of premises, according to which the calculated thermal power of the heating system is determined, are taken equal to the sum of heat losses through separate external fences without taking into account their thermal inertia at tH == tH 5, i.e. at the average temperature of the outside air of the coldest five-day period, corresponding to K about == 0.92. In addition to Toro, heat losses or gains through internal fences must be taken into account if the temperature in adjacent rooms is lower or higher than the temperature in the design room by 3 The reduced resistance to heat transfer of the fencing or ero is the heat transfer coefficient ko == l / RO, k included in formula (2. 2), are taken according to the heat engineering calculation in accordance with the requirements of the current SNiP "Construction heat engineering" or (for example, for windows, doors) according to the manufacturer's organization. There is a special approach to the calculation of heat loss through floors lying on rpYHTe. The transfer of heat from the ground floor room through the floor structure is a complex process. Considering the relatively small specific gravity of heat loss through the floor in the total heat loss of the room, a simplified calculation method is used. Heat loss through the floor located directly on the rpYHTe is calculated by zone. For this, the floor surface is divided into 2 m wide strips parallel to the outer walls. The strip closest to the outer wall is designated by the first zone, the next two strips by the second and third, and the rest of the floor surface by the fourth zone. If the heat loss is calculated buried in the rpYHT of the room, the zones are counted from the ground level along the BHYT of the lower surface of the outer wall and further along the floor. The surface of the floor in the zone adjacent to the outer corner of the room has increased heat loss, therefore, its area at the point of abutment is taken into account twice when determining the total area of ​​the zone. The calculation of heat loss by each zone is carried out according to the formula (2.2), taking ni (1 + VJ == l, O. For the value Ro, i, the conditional resistance to heat transfer is taken from the non-insulated floor RH p, m 2 OC / W, which for each zone is taken equal to : 2.1 for the first zone; 4.3 for the second zone; 8.6 for the third zone; 14.2 for the fourth zone. W / (m Oy.c J Au.c) "(2 3) -de 8us thickness of the insulating layer, m; Aus thermal conductivity of the material of the insulating layer, W / (m.oC). of each floor zone R l, m 2 .o s / w, is taken equal to 1.18 Ry.n (here, as the insulating layers, the air gap and flooring along the laminae are taken into account). the calculation of heat losses through them must be calculated in compliance with certain measurement rules. As far as possible, these rules take into account the complexity of the process of heat transfer through the elements of the fence and provide for conditional increases and decreases in areas, when the actual heat losses MorYT are, respectively, more or less than those calculated by the accepted simplest formulas. As a rule, areas are determined by external measurements. The areas of windows, doors and skylights are measured over the smallest building opening. Ceiling and floor areas are measured between the axis of the interior walls and the interior surface of the exterior wall. Floor areas by rpYHTY and lamellas are determined with their conditional division into zones, as indicated above. The areas of the outer walls in the plan are measured along the 32nd outer perimeter between the outer edge of the building and the axes of the inner walls. Measurement of external walls in height is carried out:. on the first floor (depending on the floor structure) or from the outer surface of the floor along the rpYHTY, or from the surface of the preparation for the floor structure on the lats, or from the lower surface of the ceiling above the underground or unheated under the bulkroom to the clean floor of the BToporo floor; ... in the middle floors from the floor surface to the floor surface of the next floor; ... in the upper floor, from the floor surface to the top of the structure, there is an attic floor or an attic floor. If it is necessary to determine the heat loss through the internal firewalls, their areas are taken by the internal measurement. The main heat losses through the fences, calculated by formula (2.2) at Bi == О, often turn out to be less than the actual heat losses, since this does not take into account the influence of some factors on the heat transfer process. Heat losses MorYT change noticeably under the influence of infiltration and exfiltration of air through the thickness of the walls and cracks in them, as well as under the action of solar irradiation and "negative" radiation of the outer surface of the walls towards the sky. Heat losses of the room as a whole MorYT increase due to temperature changes along the height, cold air bursting through openings, etc. These additional heat losses are usually taken into account as additions to the main heat losses. The amount of additives and their conditional division according to the determining factors are as follows. An addition for orientation by cardinal points (sides of the horizon) is applied to all external vertical and oblique (their projection onto the vertical) images. The values ​​of the additives are taken in accordance with the diagram in Fig. 2.1. For public, administrative and industrial buildings, in the presence of two or more external walls in the room, additives for orientation on the sides of the horizon for all YKa, the above fences increase by 0.05 if one of the fences faces north, east, ceBepO BOCTOK and north west, or by 0.1 in other cases. In typical projects, these additives are taken in the amount of 0.08 for one outer wall and 0.13 for two or more walls in a room (except for residential), and 0.13 in all living quarters. For horizontally located fences, an additive in the amount of 0.05 is introduced only for unheated floors of the first floor above cold underground buildings in MeCTHOs with a design outside air temperature of minus 40 oC and below, from 33 s: :) n! O Fig. 2.1. Diagram of the distribution of additives to the main heat losses for the orientation of external fences in the cardinal directions (sides of the horizon) Additive for the intake of cold air through external doors (not equipped with air or air heat curtains) during their short-term opening at a building height H, m, from the average planning level ground marks to the top of the cornice, the center of the exhaust openings of the lantern or the mouth of the ventilation shaft are taken: for triple doors with two vestibules between them in size Bi == 0.2H, for double doors with vestibules between them 0.27N, for double doors without vestibule 0.34H, for single doors 0.22H. For external gates, in the absence of a vestibule and air-thermal curtains, the additive is equal to 3, if there is a vestibule at the gate 1. The above additives do not apply to summer and emergency external doors and gates. Previously, the norms provided for an addition to the height for rooms with a height of more than 4 m, equal to 0.02 for each meter of wall height over 4 m, but not more than 0.15. This allowance takes into account the increase in heat loss in the upper part of the room, since the air temperature increases with height. Later, this requirement was excluded from the rules. Now in high rooms it is necessary to make a special calculation of the temperature distribution along the BЫ honeycomb, in accordance with which the heat loss through the walls and coverings is determined. In stairwells, the temperature change along the height is not taken into account. Example 2.1. Let us calculate the heat loss through the fences of the premises of a two-story dormitory building located in Moscow (Fig. 2.2). The design temperature of the outside air for heating is tH 5 == 26 OC. The heat transfer coefficients of external fences k, W / (m 2. 0 С), determined by the heat by technical calculation, as well as by standard or reference data, are assumed to be equal: for external walls (Нс) 1.02; for attic floor (Fri) 0.78; for double-glazed windows with wooden frames (Up to) 2.38; for external double wooden doors without vestibule (Нд) 2,33; for the inner walls of the staircase (Vs) 1.23; for a single inner door from the staircase to the corridors (Vd) 2.07. 34 4.86 t 1. 2 t 3.2 (: 1t 3.2 f r "" "О ...., ... .. ..;" Т! ...... ...... C "" - J пм I О l ( 20 I) 11 102 2 02 3.2 / C s: -I s q rJ Fig. 2.2. Plan and section of the premises of the dormitory building (for examples 2. 1, 2.2 and 2.3) The floors of the first floor (Pl) are made on laths. Thermal resistance of the closed air layer R vp == 0.172, m 2 .os / W, the thickness of the plank flooring 5 == 0.04 m with thermal conductivity X = 0.175 W / (m OS). The thermal resistance of the insulation layers KOHCT of the floor is equal to: R B. rт + .3 I А == О) [72 + O, 04/0 t 175 О 4З M2.0C / BT Heat losses through the floor on the bays are determined by zones. Conditional resistance to heat transfer, m 2 .os / W, and heat transfer coefficient, W / (m 2 .0С), for zones 1 and 11: RI ==!, 18 (2, 1 + 0.43) == 3, 05; k :::; 1 / 3.05: ;; O 3 2 8 RI = 1118 (4.3 + 0.43) 5.6; k 1 == 1 / 5t 6;: O 178. For non-insulated staircase floor RI; :::; 2,; k J = O 46S; RII == 4 W; k ii; ::; O 23 2 .. Heat loss through separate fences is calculated by formula (2.2). The calculation is summarized in table. 2.1. 35 Table 2.1. Calculation of heat loss in premises 11 ;:;: ;;:; : r: "" 3 I! -: "::: = .: o s I fаl1МС! lOrнshe u: to: ./11. o :: s: I: rooms and r: 1" () o n: m t avg ryp 1., .. C J 2 l.Ql W la: R CONN ip-i "yrrYu8dR) 20 nlT nnlJ I: D2. Living room p5il HOUSE, 18 t Ic. BEFORE PLl PlII sun 201 Residential connip url" 1O8aYa r 20 HARSH "; -" 1 cfnc HI \ I (IorRaREDSHiiYa: ;; 11 [9 g. r! Ija Mcp "l m:! Ii:;:;: t; s 4 5 1" 01: I:. . B i :) 171.2 18.0 1 8 16.4 4.4 N, B ca 6.4 6.4 11.4 15.1 15rB lt B 16.6 ... ......... O : Q: U о р .. t- о 1: = ... ::. T: (1,10:!:: =;:; OJ g -e rC: I.-Е- е- 8 о 6 7 v c..J-: t: I .. p .. .. :: .. f: r ["(1 and o .... (ICI ou n .. i :: :): IU. ..... 8: 46 46 46 46 46 4-4 ф4 Ф4 44 (18 12) 46 46 4b bCHO I 9 -) i; 6a "IM, ..... Q .. (] о;: r - IXI g о х ::: 1: О L "% I -о ::: 1: -u О 9 М7 844 113 2i7 Зб 530 108 92 50 84 708 741 113 543 n: rB / 2) (3.7 115: 0: 1.1 3.2) 0; 2 3 f2 x 2 3 f8 x 3 o 0/1 0.1 o o o] 1.1 1,] 807 928 124 Not SW Not NW Do sz nr I . -1/66 ": -: 3125 4186: -: 3/25 lt 5: (1 t2 4.2) (4 Ot] 0.:1 o o 247: 2142 797 2939 o 011 0.1 o o o 1! 1 jl 1 1 I 58]] / 2) (4 12.8 0.78 38xO, 9 3``11. 1 341 PpI. 3 / .2x2 6 (0.465 38 113. 1 113 PPP 3 J 2 x2 BA 0.232 for 55 1 56 8d. 1, bx2 r 2 W / 5 2.07 (12 18) AZ "l 4Z ee 2 (3t 8x6, 2) + 61 1.23 () IR and. 1 + L (6.P2 1t2A 2) /, 2 + L (6РЗ)