Heating is to supply heat to the room manually to keep the room at a certain temperature to create suitable living conditions orWorking conditionsTechnology.
The heating system consists of heat source（Heat mediumPreparation), heat circulation system (pipe network or heat medium transportation) and heat dissipation equipment (heat medium utilization).
Chinese name
heating system
Foreign name
Heating system
Composition
Heat source, thermal circulation system and heat dissipation equipment
Heat medium classification
Hot water heating system, steam heating system, hot air heating system
Heat source classification
Thermal power plant heating, regional boiler room heating, central heating
The basic working principle of the heating system: the low-temperature heat medium is heated in the heat source and becomes the high-temperature heat medium (high-temperature water or steam) after absorbing the heatTransmission pipelineSend it to the room and release heat through the heat dissipation equipment to raise the indoor temperature;After heat dissipation, the temperature decreases and becomes a low-temperature heat medium (low-temperature water), which returns to the heat source through the recovery pipeline for recycling.In this way, the heat is continuously sent to the room from the heat source to supplement the indoor heat loss and keep the room at a certain temperature.
heating system
system composition
Announce
edit
The heating system is composed ofheat source, heat medium transmission pipeline and heat dissipation equipment.
Heat source: equipment for producing steam or hot water with pressure, temperature and other parameters.
Heat medium transmission pipeline: transfer heat from heat source toHot userThe piping system of.
Heat dissipation equipment: equipment that transmits heat to indoor air.
Equipment composition
Announce
edit
The heating system involves many equipment and facilities, including:
Boiler Room
The boiler room is the heat source of the heating system, which is mainly composed of the following parts:
Coal conveying and ash removal system: including coal crushing, screening, conveying, lifting, ash removal, slag removal equipment, etc.
Outdoor heating network
outdoorHeatingpipe networkThe main laying methods ofOverhead layingBuried laying is common. Buried laying can be divided into ventilation trench, semi ventilation trench, non ventilation trench and direct burial. The main equipment and facilities involved include water supply and return pipes, various valvesTelescopic device, supportFlange gasketPipe trench and roofExpansion water tankEtc.
Indoor heating system
Indoor heating systemIt mainly refers to the indoor water supply and return pipesExhaust valveExpansion valve, heat dissipation equipment and indoor trench, etc.
1. According to different classification of system cycle power
According to the different circulating power of the system,Hot water heating systemIt can be divided into natural circulation system and mechanical circulation system.Fluid dependentDensity differenceThe system for circulation is called "natural circulation system";The system that circulates by the external mechanical (water pump) force is called "mechanical circulation system".
2. Classification by water supply and return modes
According to the different ways of water supply and return, the hot water heating system can be divided into single pipe system and double pipe system.stayHot water heating system for high-rise buildingsIn, single and double pipe hybrid systems are mostly used.
3. PressPipe layingDifferent classifications of methods
4. Classification according to temperature of heating medium
According to the temperature of heat medium, hot water heating system can be divided into low-temperature heating system (water supply temperature t<100 ℃) and high-temperature heating system (water supply temperature t ≥ 100 ℃).Each countryHigh temperature waterandLow temperature waterWe have our own regulations on the boundaries of.In China, it is used to think that hot water below or equal to 100 ℃ is called "low-temperature water";Water above 100 ℃ is called "high-temperature water".Indoor hot water heating systemMost of them use low-temperature water for heating and are designed to supplyReturn water temperature95 ℃/70 ℃ is adopted. High temperature water heating should be used in production plants.
Classification of steam heating systems
Centralized hot water supply system with steam as heat medium
As provided bypressureThe steam heating system is divided into two categories: gas supplyGauge pressure(Pressure higher than atmospheric pressure) equal to or lower than 70kPa, belonging toLow pressure steam heating system；The gauge pressure (higher than atmospheric pressure) of air supply is higher than 70kPa, which belongs to high-pressure steam heating system.When the air supply pressure decreasesSaturation temperatureAlso reduced,CondensateThe secondary gasification capacity is less, the operation is more reliable, and the sanitary conditions are also improved.stayCivil buildingsThe pressure of the steam heating system should also be as low as possible.
System characteristics
Announce
edit
The advantages of the heating system with water as the heat medium are: the room temperature is relatively stable and the sanitary condition is good;canCentralized regulationWater temperature, easy to adjust heat dissipation according to outdoor temperature changes;The service life of the system is long, generally 25 years.
Disadvantages of the heating system with hot water as the heating medium: when low-temperature hot water is used as the heating medium, the pipes and radiators are more dissipated, and the initial investment is larger;When the building is highhydrostatic pressureLarge, the radiator is prone to overpressure;WateryThermal inertiaLarge, the room temperature rises and cools slowly;When the hot water is not completely discharged, the frost cracking accident is easy to occur.
Hot water heating systemIt can be divided into gravity circulating hot water heating system andMechanical circulating hot water heating systemTwo, the mechanical circulating hot water heating system is a heating system that uses pipes to connect the boiler, water pump and user's radiator.
In the heating system, the connection mode of each radiator and pipe is called the form of cooling system.The form of heat dissipation system in hot water heating system can be divided into vertical type and horizontal type.
(1) Vertical
It refers to that the radiator with the same vertical positionRiserHow to connect.According to the connection mode of radiator and riser, it can be divided into single pipe system and double pipe system;According to supplybackwaterThe layout position and water supply direction of the main pipe can also be divided into upper supply and lower return, lower supply and lower return, and lower supply and upper return.
(2) Horizontal
It refers to the method of connecting radiators at the same horizontal position (the same floor) with a horizontal pipe.It can be divided into two ways: sequential and leapfrog.The advantages of sequential type are simple structure and low cost, but each radiator cannot be adjusted separately;Each radiator in the spanning type can be adjusted independently, but the cost is high, andHeat transfer coefficientLower.
Compared with the vertical system, the horizontal system has the following advantages.
② The pipeline is simple, there is no riser passing through each floor, and the construction is convenient.
③ Horizontal pipes can be laid in ceiling or trench for concealment.
④ It is convenient for hierarchical management and adjustment.
However, the exhaust mode of horizontal system is more complicated than that of vertical system, which needs to be set on the radiatorCold air valveDecentralized exhaust, or connect an air pipe in series on the radiator on the same layer for centralized exhaust.
4、 Steam heating system
Steam heating system can be divided into high pressure and low pressure according to different steam pressure.The characteristics of the steam heating system are described below.
The selection of heating medium for heating system should be based on the characteristics of heating medium, hygiene, economy, nature of use, district heating planning and other conditions, as shown in the following table
