Heating of a nine-storey residential building

Contents

Contents

Introduction

Source Data

Selection of heating system

Heating System Design

3.1 Determination of water flow rate in heating system

3.2 Design circulation pressure in heating system

3.3 Hydraulic calculation of heating system by specific losses

friction pressure

3.4 Circulation pressure in the main lines and risers of the system

heating

Selecting and Placing Heating Appliances

4.1.1 Definition of temperature controller setting

Thermal Calculation of Heating Appliances

Conclusion

Bibliographic list of used literature

Introduction

Each of the heating systems is designed to achieve a common goal - to supply the necessary amount of heat to the heated room during any period of the heating season. Each heating system consists of three main elements: a heat point in which the necessary amount of heat is transferred to the coolant, a system of heat pipelines for moving the heat carrier and heating devices along them.

Heating systems are subject to a number of requirements, which can be divided into five groups :

1. sanitary and hygienic - (maintaining within the specified limits of the internal temperature of the room; limiting the surface temperature of heating devices ).

2. Economic - (lowest material costs, economical consumption of fuel or heat).

3. Architectural and construction - (correspondence to the interior of the room, compactness).

4. Production and installation - (minimum number of unified units and parts, mechanization of their manufacture, reduction of manual labor costs).

5. Operational - (efficiency, reliability, durability, technical excellence, safety, etc.).

The division of requirements into five groups is conditional, since they include requirements related to both the design and construction period and the operation of the building.

The most important sanitary and hygienic and operational requirements are caused by the need to maintain this temperature in the premises during the heating season and the entire service life of the system.

Source Data

According to the assignment, the course project on the topic: "Heating of a residential 9-story building" is carried out for the city of Krasnodar. Heat engineering calculation of external enclosing structures was carried out in the course work on construction thermophysics. The heating capacity of the heating system for each room is determined during the course work according to the theoretical basics of creating a microclimate in the room and is presented in Annex 1.

Selection of heating system

Heating systems according to the location of the main elements are divided into local and central. In local heating systems, all 3 elements are structurally combined into one device (furnace heating, gas heating, electric heating). In central heating systems, the heat generator is located outside the heated room, and only the heating device is located in the room itself.

Depending on the coolant used, the central heating systems are divided into three groups, water, steam and air heating systems. According to [1], water heating systems are used for heating residential buildings.

Also, heating systems are divided into gravitational (with natural circulation) and pumping, according to the power supply scheme of the devices double-tube and single-tube, according to the location of the highways with upper and lower mains wiring, according to the flow pattern of the coolant dead end and associated .

In this course design, a heating system with pump circulation was selected, two pipe with upper wiring.

According to existing norms and regulations, with a large length of buildings, the design of a heating system with natural circulation is economically unprofitable, due to the need to use pipes of large diameters and an increase in metal consumption due to this. Therefore, heating systems with artificial coolant circulation are arranged in such buildings.

For use, it is recommended to use systems with dead end movement of the coolant with a small number of risers in individual branches. In two pipe heating systems, due to the small amount of natural pressure in the devices of the lower floors, it is possible to lag behind in the heating of the lower rooms. In modern heating systems, this drawback can be eliminated by increasing the hydraulic resistance of the heating system by installing manual or automatic balancing valves and automatic temperature controllers.

Modern heating systems can be used in the presence of high-quality coolant, since the minimum section for coolant passage in the DANFOS crane is less than 1.8 mm.

Heating System Design

The operations for designing the heating system consist of four main sections: calculation of thermal power (performed in CG according to TOCM), selection, design and thermohydraulic calculation of the heating system .

The design of the heating system begins with the placement of the heat center, thermal pipelines, heating equipment of buildings .

When placing pipes, decisions are made on direction and magnitude of slope, compensation of elongations and thermal insulation, organization of movement, collection and removal of air, selection and location of reinforcement.

On the plans of the basement and attic rooms show the main equipment with technical characteristics, highways with indication of diameters and slopes, risers with numbers, introduction of external heat pipelines, shutoff valves, sections with thermal insulation, make up diagrams of pipelines and equipment of the heat center and heating system.

Diagrams of mains and heat point are drawn in axonometric projection. The diagram shows equipment, pipes with shut-off devices, heating devices, air collectors, drain cranes, etc. On the diagrams, the following are applied: pipe slope, riser numbers, heat load and diameter of sections of mains and risers, water flow rate in risers, heat load and design area of ​ ​ instruments.

Thermohydraulic calculation of heating system includes determination of temperature, pressure and flow rate of heat carrier, diameter of heat conductors, type size of equipment.

Hydraulic calculation is carried out up to thermal in the case when the dimensions of the heating elements practically do not affect the hydraulic resistance of the system. As a result of hydraulic calculation, diameter of heat conductors and parameters of heat carriers are determined, and then dimensions of heating elements are determined.

Selecting and Placing Heating Appliances

When choosing the type and type of heating device, the purpose and features of the thermal mode of the room, the duration of the stay of people in it, the peculiarities of the technological process, as well as architectural planning and construction solutions, on which the height, depth and length of the heating device depend, are taken into account. Recommendations for selection of heating devices and limit temperature on their surface are given in [1].

First of all, they take into account the sanitary and hygienic requirements for the room. In addition, when selecting a heating device, the operating pressure in the heating network and the heating system, the customer's requirements for the appearance of the device, the quality of the coolant, etc. are taken into account .

In residential and public buildings, heating devices, as a rule, install automatic temperature controllers.

For more information about selecting and placing heating devices, see [1].

Conclusion

During the design of the heating system of a multi-storey building located in the city of Irkutsk, hydraulic and thermal calculations were carried out, the type of heating devices was selected and their surface was calculated.

Based on the results of the hydraulic calculation of the heating system, it can be concluded that the largest pressure losses are located in the balancing valve (which is installed to reduce the effect of natural pressure on circulation in the system) and temperature controllers .

As a result of the use of temperature controllers and balancing valves, the heating system meets all modern requirements. At the same time, it should be noted that the project produced is not ideal and, if necessary, can be improved by using the latest equipment and thermal insulation of pipelines. Also, the efficiency of this heating system can be increased by choosing new heating devices (provided that the quality of the coolant is improved).

Efficiency of heating plants is ensured by optimizing design solutions and using computers, giving the plants reliability, and operation, automatic maintenance of the required coolant temperature. Operating modes are being studied, methods are being sought to control heating plants to save thermal energy.

Bibliographic list of used literature

1. SNiP 41012003. Heating, ventilation and air conditioning/Gosstroy of Russia. - M.: FSUE CPP, 2004.

2. Andreevsky A.K. Heating: text. Manual for universities. - 2nd ed. - Minsk: Vyssh. Shq., 1982.

3. Novoseltsev B.P. Heating devices of water and steam heating systems: a reference manual for students studying in specialty 270109 "Heat and gas supply and ventilation." Voronezh VGASU 2006.

4. Designer Reference Book. Heating, water supply, sewerage/edited by Staroverov I.G. - M., 1975. Ch.1.

5. GOST 21.602 - 2003. Design documentation system. Rules for filling working documentation of heating, ventilation and air conditioning/Interstate Scientific and Technical Commission. M of 2004.

SNiP II379 *. Construction heat engineering/Gosstroy of Russia. – M of 1998.

7. Theological V.N., Skanavi A.N. Heating. - M.: Stroyizdat, 1991.

Лист 1.cdw

Лист 2.cdw