建筑环境与能源应用工程专业英语(1).ppt

,Unit Ten Comfort Heating,Heating System A steam (heating) system uses the vapor phase of water to supply heat or kinetic energy through a piping system. As a source of heat, steam can heat a conditioned space with suitable terminal heat transfer equipment such as fan coil units, unit heaters, radiators, and convectors (finned tube or cast iron), or steam can heat through a heat exchanger that supplies hot water or some other heat transfer medium to the terminal units. Water systems that convey heat to or from a conditioned space or process with hot water are frequently called hydronic heating systems. The water flows through piping that connects a boiler, water heater to suitable terminal heat transfer units located at the space or process. Classified by flow generation, hydronic heating systems may be (1) gravity systems, which use the difference in density between the supply and return water columns of a circuit or system to circulate water; or (2) forced systems, in which a pump, usually driven by an electric motor, maintains the flow.,Cast-iron Radiator,Expansion Tank,Electric Boiler,Relief Valve,Pump,Return Pipe,Cold Water Fill,Supply Pipe,Radiator,In the direct-return system, the length of supply and return piping through the subcircuits is unequal, which may cause unbalanced flow rates and require careful balancing to provide each subcircuit with design flow. Ideally, the reverse-return system provides nearly equal total lengths for all terminal circuits.,Solar Altitude and Solar Azimuth,S,Normal,Solar Altitude,Solar Azimuth （偏东为负，偏西为正）,The current value of the solar constant (which is defined as the intensity of solar radiation on a surface normal to the suns rays, just beyond the earths atmosphere at the average earth-sun distance) is 1367 W/m2.,大气层外太阳辐射强度随日期的变化,Spectral Solar Irradiation,99 的能量集中在在0.28m到5.0m的波段之间。,Direct solar radiation,Diffuse solar radiation,Global solar radiation,Global solar radiation Direct solar radiation Diffuse solar radiation,Shorter wavelength High proportion,Longer wavelength,Temperature increase,Greenhouse effect,Five Elements of Passive Solar Home Design Aperture (Collector) The large glass (window) area through which sunlight enters the building. Absorber The hard, darkened surface of the storage element. Thermal mass The materials that retain or store the heat produced by sunlight. Distribution The method by which solar heat circulates from the collection and storage points to different areas of the house. Control Roof overhangs can be used to shade the aperture area during summer months.,Active solar heating system,1: Sensor 传感器 2: Air Vent 排气口 3: Sensor wire 传感器线 4: Pump or circulator 循环泵 5: Pressure Relief Valve 减压阀 6: Sensor 传感器 7: Pressure Relief Valve 减压阀 8: Thermometer 温度计 9: Tempering Valve 混水阀 调温阀 10: Hot water output 热水输出 11: Cold water feed line 补水管 12: Knob adjusts water temperature output 13: Bypass “H” valve 旁通阀 14: Check Valve 逆止阀 15: Solar collectors inlet 太阳能采集器入口 16: Pressure Relief Valve 减压阀 17: Collectors & Absorber Plate 太阳能采集器 18: Auxiliary heater 辅助加热器 19: Storage Tank 储热罐 20: Differential controller 温差控制器 21: Pressure gauge 压力表 22: Pressure storage tank 储压罐 23: Flowmeter 流量计,Solar heating systems,Central solar heating system with seasonal storage,1. Heat Transfer and Fire Tube Boilers Heat Transfer ranks second Fire Tube Boile rs 2. Solar Energy The greenhouse principle Basic solar system components Instrumentation Collectors Absorber Plate Heat Storage 3. System Controls System controls for heat storage Space Thermostat Temperature Sensors Control Panel Differential Thermostat,Frequently used words and phrases: fire tube boilers 火管锅炉 hydronic heating 循环供暖 secondary heat exchanger 二次热交换器 insulating effect 绝热效应 firebox 燃烧室 alternate energy sources 替代能源 cloud cover 云量 shorter wavelength 短波 longer wavelength 长波 absorber plate 吸收板 antifreeze 防冻剂 pressure storage tank 储压罐 relief valve 排气阀 fiberglass 玻璃纤维 centrifugal pump 离心泵 check valve 逆止阀 thermostat 温控器 auxiliary heater 辅助加热器 control panel 控制台(面板) greenhouse 温室 differential thermostat 差示恒温器 ASME 美国机械工程师协会 American Society of Mechanical Engineers,Frequently used words and phrases: fire tube boilers 火管锅炉 hydronic heating 循环供暖 secondary heat exchanger 二次热交换器 insulating effect 绝热效应 firebox 燃烧室 alternate energy sources 替代能源 cloud cover 云量 shorter wavelength 短波 longer wavelength 长波 absorber plate 吸收板 antifreeze 防冻剂 pressure storage tank 储压罐 relief valve 排气阀 fiberglass 玻璃纤维 centrifugal pump 离心泵 check valve 逆止阀 thermostat 温控器 auxiliary heater 辅助加热器 control panel 控制台(面板) greenhouse 温室 differential thermostat 差示恒温器 ASME 美国机械工程师协会 American Society of Mechanical Engineers,2. The transmission or flow of heat ranks in the field of engineering second only to problems involving the strength of materials.,hydronic heating: 循环供暖 secondary heat exchanger: 二次热交换器,rank: 按等级排列 strength of materials: 材料强度,approach: 方法 blind acceptance: 盲目接受 elementary: 基本的 gross: 显著的 十足的 粗糙的,Hydronic heating maintains comfort in the home by circulating hot water to the secondary heat exchanger.,3. In their approach to a problem involving heat transfer, their possible blind acceptance of published elementary laws governing heat flow may lead to gross error in the solution.,6. The crown sheet and side walls in the firebox provide a maximum amount of radiant heat transfer surface.,As noted: 众所周知的 insulating: 绝缘的 绝热的 保温的 film of stagnant gas: 滞留气体层 cling to: 依附,crown sheet: 顶板 side wall: 侧壁 firebox: 燃烧室 radiant: 辐射的,in the way of heating surface allowances:在受热面可以承受的情况下 temperature differential: 温差 scrubbed off:去除,4. As noted, the chief resistance to the free flow of heat from the source to the point of use is the insulating effect of the film of stagnant gas that always tends to cling to a heat transfer surface.,5. For effective heat transfer and all that it means in the way of heating surface allowances, safe temperature differentials, economical operation, and life of equipment, the stagnant gas films must be effectively scrubbed off the heating surfaces.,8. Solar energy is the most popular of the many alternate energy sources being discussed today.,copper clad: 镀铜的 waterside: 水侧的 the most aggressive conditions: 最不利条件,alternate: 替换的 替代的,scarce: 稀少的 有限的 ever-increasing price: 一直在升高的价格,7. The firing tubes are copper clad on the waterside. Long tube life is positively assured under the most aggressive conditions.,9. Solar energy is an alternative that can reduce our dependence on scarce fossil fuels with their ever-increasing price.,11. However, solar energy can vary from season to season, from 2000 Btu to as low as 500 Btu per square foot per day during a period from June to December.,deposit: 堆积 积累 1400BTU/ft2 .day= 15.9MJ/m2.day solar constant I0=1367 W/m2,How to translate?,cloud cover: 云量,10. Each day the sun deposits an average of 1400 Btu per square foot of area to the United States;,12. Factors such as cloud cover and geographical location affect the total amount of solar energy received.,14. This is possible because ordinary glass can transmit the shorter wavelength, visible parts of the sunlight while at the same time preventing the passage of the longer wavelength, invisible heat waves.,separate from: 除过 greenhouse: 温室,ordinary: 普通的 transmit: 传播 传递 passage: 通过 shorter wavelength: 短波 longer wavelength: 长波,assemble: 组装装配 low concentration: 低密集度,13. Separate from the more obvious uses of energy from the sun, such as drying food and warming people, the most common direct use of solar energy is in a greenhouse.,15. To get the most from solar energy, a system must be assembled to collect the low concentration of solar energy efficiently and store the heat energy to use at night and on cloudy days.,17. This data can be obtained from a pyronometer, a device that measures insolation (energy from the sun) in Btu per square foot per hour.,proposed: 被提议的,reading: 读数 carry away: 带走,pyronometer: 日射强度计 insolation: 日射能量,16. Designing a solar installation requires precise information on the amount of solar energy available at the proposed location.,18. Heat flow readings can be compared to insolation data to show how efficiently the collector is operation; that is, how much of the available energy is being carried away by the collector system.,measurement of diffuse solar radiation,The global solar radiation can be divided into two components: 1) diffuse solar radiation, which results from scattering caused by gases in the Earths atmosphere, dispersed water droplets and particulates; 2) direct solar radiation, which havent been scattered. Global solar radiation is the algebraic sum of the two components.,19. Most collectors contain an all-copper absorber plate because of the effective heat transfer characteristics of copper.,absorber plate: 吸收板 heat transfer characteristics: 传热特性,domestic water: 家庭用水,conduct: 传导 copper fluid-carrying piping arrangement: 铜制的液体输送装置,20. As the temperature of the absorber plate increases, solar heat is conducted from the absorber plate through a copper fluid-carrying piping arrangement.,21. When this design is used, additional heat exchangers must be used to heat the domestic water and the water used for heating purposes.,22. Water is sometimes used as the heat transfer fluid. It should be mixed with antifreeze or an automatic drain-down system to protect the system from freezing during cold weather and when the solar collector system is shut down, such as when the storage medium has reached the desired temperature and fluid flow through the collectors is stopped.,antifreeze: 防冻剂 automatic drain-down system: 自动排水系统,pressure storage tank: 压力储存罐 relief valve: 减压阀 vent: 放出 排出, 通风口, 给开口,23. A properly sized pressure storage tank should be used or the tank should be vented to the atmosphere and fitted with the proper size relief valves.,25. The pumps used to circulate the heat transfer fluid are generally low velocity, centrifugal pumps.,fiberglass：玻璃纤维 withstand: 经受住,check valve: 逆止阀 array: 排列 upset: 扰乱,centrifugal pump: 离心泵,26. Check valves are installed between the heat transfer fluid pump and the collector array. They prevent a reversed flow of the fluid through the system, which would tend to upset th