【 Weak current College 】 heating and gas supply---the first section of the heating system overview

This section describes the basic components of the heating system, heating system of classification, hot water heating systems and steam heating system, etc, through the study should be aware of the heating system of formation, classification, hot water heating system works. First, the basic form of heating system of heating is artificial methods to supply the heat indoors Interior maintain a certain temperature, to create appropriate living conditions or working conditions. Heating system from sources of heat (thermal media preparation), thermal cycle system (supply or htm transportation) and thermal equipment (htm use) of three main parts. ① heat source: heat generator, used to produce heat, a heating system supply heat source. Heat source is currently comprised of the following: boiler room, thermal power plants, industrial waste heat, nuclear, solar and geothermal, etc. ② heat circulation system: for heat transport of pipes and equipment, is the heat of the channel. ③ thermal equipment for heat transfer into the Interior of the device, is heating system load equipment. 　　Our use of thermal equipment radiator, heater and radiation plate. In the heating system, assuming the material is known as the heat transfer medium.　　Commonly used htm has two water and steam. Heating system of the basic working principle: in low temperature heat source htm is heated, the absorption of heat, becomes a high-temperature thermal (hot water or steam), via pipeline to the Interior, through emitting radiator equipment heat indoor temperature; temperature decrease after heat into low-temperature thermal (cold water), and then through the return line returns the heat source, for recycling.　　So continuous loop, thus continuously transfers heat from the heat source to the Interior, to complement the Interior heat loss, to maintain a certain temperature indoors. Second, the heating system of classification 1. depending on the sort of htm ① hot water heating: hot water heating system for htm, press the hot water temperature, and can be further divided into low-temperature heating systems (water temperature lower than 100 ° c) and hot water heating systems (water temperature higher than 100 ° c); according to the different cycling power, divided into natural circulation system and mechanical circulatory system. ② steam heating: steam as heating medium of heating system, it can be divided into low pressure steam heating system (air pressure is not greater than 70kPa) and high pressure steam heating system (pressure greater than 70kPa) and vacuum steam heating system (pressure below atmospheric pressure). 　　③ hot air heating: according to the air heating device for installation locations, divided into central air supply system and heater system. 2. the scope of the different classification ① local heating system: thermal media preparation, transportation and htm use htm three main components are constructed with heating system. ② Central heating system: heat and thermal equipment set, connected with htm pipeline, from sources of heat to each room or individual building supply heat heating system. 　　③ district heating system: a wider range of heating systems, usually heat supply one or more of several community buildings.　　3. hot water heating system water to heat heating system advantages: its relatively stable at room temperature, good health conditions; to focus on regulating the water temperature, easy changes according to the outdoor temperature regulating the heat quantity; system using long life, generally used for 25 years.　　Hot water heat heating system weaknesses: the use of low-temperature hot water as htm, pipe and heat dissipation of the initial investment is large; the higher the buildings, the system of hydrostatic pressure, overpressure radiator is easy; water thermal inertia, room heating and cooling is slow; hot water discharge is not thorough, vulnerable to frost crack failure.　　Hot water heating system pressure by their function, can be divided into gravity circulation of hot water heating systems and machinery circulation two hot water heating systems, machinery circulation of hot water heating system is piped to boilers, water pumps and users connect to form a radiator heating systems. In heating systems, various heat sink and pipe connection methods are called in the form of heat dissipation system.　　Hot water heating system cooling system can be divided into vertical and horizontal. (1) vertical
The vertical position of the same individual radiator connections with risers.　　By radiator and risers of connection methods can be divided into single-pipe system and two-pipe system for two; press, backwater dry pipe layout location and direction of water supply can be divided into different also for next, next, on to the next and the following eturn several ways. (2) horizontal
Means the same horizontal position (same floor) of each radiator with a horizontal pipe connections. It can be divided into sequential and spanning two ways.　　Sequential advantage is structure is relatively simple, low cost, but the heat sink is not a separate regulation; spanning the radiator can be adjusted independently, but the cost is high, and lower the heat transfer coefficient. Horizontal system and vertical system has the following advantages compared to. ① construct simple and economic. ② pipeline are simple, not through the floor of the risers, construction convenient. ③ horizontal pipes can be laid in ceiling or trench for concealment. 　　④ facilitate tiered management and tuning.　　But how horizontal system exhaust than vertical system complexities, it needs to be set on the heat sink cooling air valve dispersion exhaust, or in-floor heat sink threaded a centralized exhaust air pipe. 4. steam heating system steam heating system by steam pressure of high-pressure and low-pressure is divided into two types. Steam heating system features described below. ① steam heating system of the radiator surface temperature is high. ② steam heating system than the mechanical recycling of energy saving hot water heating system. ③ steam heating system of small thermal inertia. ④ Save high pressure steam heating system pipes. ⑤ steam heating system suitable for high rise buildings. ⑥ steam heating system heat loss. ⑦ steam heating return pipe life short.