【 Weak current College 】 heating and gas supply-section II-heating equipment

This section includes heating system devices, heating equipment. 　　Learn when to clear the heating system of the device. First, the heating system of the equipment composition 1. heat source equipment heating system is responsible for providing the entire system of thermal equipment for heat source equipment, commonly used heat source equipment mainly has the following two ways. ① boiler: heating system to fuel combustion heat energy released when, after thermal water (htm) into steam (or hot). ② heat exchanger: heating system by two temperature different hot swap between htm to system indirectly provides heat energy. 　　Common heat exchanger there is gas-to-water heat exchangers and water-water heat exchanger. 2. cooling device it is installed in the heating room of a heat exchanger, often called the heatsink.　　Hot water (or steam) flowing through the radiator heat through it will be passed to the indoor air, so as to achieve the purpose of the room heating. 3. loop power equipment it is loop through heat and realization of heating equipment.　　Water pump is the main loop of the heating system of power equipment. 4. pipe, auxiliary equipment and devices in the heating system, in addition to these three basic equipment, in order to make the system work properly, you need to set the necessary auxiliary equipment. ① to eliminate hot water volume with temperature changes and set expansion tank, to exclude water gas and the gas tank is set and the steam trap. ② the circulatory system commonly used pipeline equipment include: heating (steam) pipes, heating water return (condensate) tube and add water to the system of water pipes, etc. There are also used for pipe connections of all kinds of connectors, for use with fixed pipeline trestle and used to control the heat medium flow rate of various valves, etc. 　　③ heating systems also need to set the thermometers, pressure gauge and monitoring equipment used for system heat medium (water or steam) of various State monitoring for system operation and management to ensure the system's normal operation. 2. heating equipment 1. boiler boiler is the source of heat, mainly used to produce steam and hot water.　　Typically, industrial and heating boiler as heating boilers, to distinguish them for power and electricity power boiler. (1) heating boilers of type
Heating boiler steam boilers and hot water boilers. On heating boilers, each class is subdivided into high-pressure boilers and two low pressure boiler. Steam boiler, the steam pressure of greater than 70kPa is called high pressure boiler, pressure is less than or equal to the known as low-pressure boiler 70kPa. In hot water boiler, the temperature is higher than 115 ℃ called high pressure boiler, less than 115 ° c of as low pressure boiler. Low-voltage boiler can be made of cast iron or steel manufacture, high pressure boiler is made of steel manufacturing.
Boiler fuel can be used is coal, light oil, heavy oil and natural gas and gas, use of coal as fuel is known as a coal-fired boilers, boiler and use oil or gas as a fuel in boilers as fuel or gas-fired boiler. (2) the basic structure of the boiler
Boiler furnace from the pot and is made up of two parts, in which the pot is to heat the air-water system, water supply equipment, economizer, drum and convection beam tube, etc; furnace is the chemical energy into heat energy by combustion equipment, blowers, fans, flue, duct, coal feeder, air heater, combustion equipment, dust and chimney, etc.
Fuel combustion in the furnace to produce high temperature flue gas, convection and radiation qiguo, by way of heating surface heat transfer to qiguo temperature lower water, hot water or steam. In order to take full advantage of high-temperature heat, smoke, before leaving the boilers through economizer and air heater, boiler's feed and furnace preheated air.
In order to guarantee the safety of work, the boiler boiler also should be equipped with safety valve, pressure gauge, gauge, high and low water level alarm and over-temperature overpressure alarm devices. (3) boiler performance
Boiler capacity: refers to the boiler in the unit of time to produce hot water or steam capacity, t/h.
Working pressure: boilers gas (water), steam (hot water) rated pressure, MPa.
Temperature: boilers gas (water) Department of steam (hot water) of temperature, ℃.
Thermal efficiency: refers to the effective utilization of thermal boiler with fuel input heat ratio, it is the most important economic boiler.　　General boiler efficiency of 60% to 80%. (4), boiler room
Boiler house with coal-fired boiler plants and oil and gas fired boiler plants. 2. heat exchanger for heat exchanger according to their works can be divided into surface heat exchangers, mixed-type heat exchangers and regenerative heat exchangers. ① surface heat exchanger: heat exchanger, heat between two fluids through a layer of metal wall with heat, the two are not in direct contact with the fluid. This heat exchanger common shell and tube, finned tube and plate in the form of three structures. ② mixing heat exchanger: heat exchanger, heat and cold two fluid direct contact and blend for heat, in the heat of the accompanying material exchange. ③ regenerative heat exchanger: heat exchanger with a larger storage capacity of the heat transfer surface for indirect heat. 　　Runtime thermal fluid through the heat exchanger surface, making it the heat rising temperature and storage; and cold fluid through the heat exchanger surface, absorbing its stockpile of thermal and heating. As an indirect heat source of the heat exchanger is located in the boiler room or in a separate building in the heat Chamber and as an independent source and composition of the heating system.　　This system has the following features: simple and reliable operation; condensate can be recycled, reducing the water treatment facilities and costs; the use of high-temperature water bottled water can reduce heat circulating water, reduce the net initial investment; according to the outdoor air temperature to adjust the temperature of the water method to adjust the quantity of heat, avoid the room temperature is too high. 3. radiator radiators is the heating system of the device, is on the air for heating of heat exchanger that transfers htm (hot water or steam) carried by heat transfer to the indoor air, heating purposes. Radiator is usually made of steel or cast iron manufacture, has many forms, such as columnar radiator, type radiators and convectors steel series tablets. ①: Columnar radiator can be divided into four columns, five columns and two columns of three, are made of cast iron. ② type radiators: divided into long airfoils and two round Airfoil, Made of cast iron. 　　③ steel series Tablet convection radiator: two root (or two or more) the tube with a rectangular thin sheet on many. Note: the heat sink is set in the most reasonable under wall window. Because through the heating of the air rise along the outer window to prevent the infiltration of cold air along the wall and window, thus preventing cold air directly into the rooms.　　For request not high room, radiator also reliable wall settings.　　4. water pump in the heating system, commonly used is centrifugal pump, ensuring continuous water supply, to provide loop powered heating system. 5. expansion water tank to eliminate water when heated volume expansion of setting and atmosphere with the open-expansion tank. Role is to accommodate the system water due to the increased volume of heated and supplementary system water shortage, exclude system of air, also indicates that the system level and the control system in hydrostatic pressure.　　Expansion tanks made of steel sheet for general use, usually round or rectangular.　　6. gas tank set gas tank is in hot water heating system settings to exclude air. 7. compensator telescopic device when heating system pipes conveying htm, pipeline itself due to temperature rise and swell elongation.　　Compensator for pipeline can withstand more than the permitted stress intensity and installation of equipment. 8. steam trap trap is used to exclude the steam, condensate and prevent steam leakage from the condensate pipeline equipment.　　Common trap with machinery, heat-trap-trap and constant temperature-trap three types.　　9. pressure reducing valve is used to reduce the high pressure steam pressure to use conditional request value, it can automatically control valve door open, stable pressure after the valve. 10. safety valve safety valve is a guarantee that the system in a certain pressure safety device. When the pressure exceeds the maximum allowable working pressure, valve automatically turn on to the steam system; when pressure returning to normal working pressure, the valve is closed automatically.