Study On Evaporative Cooling And Mechanical Refrigeration Compound High-temperature Chiller

Evaporative air conditioning technology is a kind of energy conservation,environmental protection, economic health air conditioning technology, but separateevaporative cooling air conditioning system have its weaknesses and vulnerable to theinfluence of outdoor air condition. As is known to all, water temperature of evaporativewater chiller is susceptible to outdoor air condition change and is instability. Theconsumption is bigger making high temperature cold water by mechanical refrigerationalone. In view of the above questions, this topic put forward the evaporative airconditioning technology and mechanical refrigeration technology is combined to makehigh temperature cold water. We cooperated with the company designed and manufacturedevaporative cooling and mechanical refrigeration compound high temperature water chiller,and applied to building. I made theoretical analysis and experimental research the chiller.Evaporative water cooling air conditioning technology are defined in the paper, andthe equipments that making cold water by the technique of are classified, divided intoevaporative water chiller and evaporative cooling and mechanical refrigeration compoundhigh temperature water chiller. Evaporative water chiller are divided into directevaporative water chiller, indirect evaporative water chiller and indirect-directlyevaporative water chiller. Outlet water temperature of evaporative was theoreticalderivated, and it’s application divided into five climate zone in psychrometric chart.This paper made the analysis aiming at this kind of the water-system. We analysedwater flow ratio between evaporation cooling chiller and the machinery refrigerationchiller and inferred change relation between both kinds of cold water current capacityallocated proportion and the water temperature of evaporative cooling chiller, and furtherfound the change relations along with the outdoor wet-bulb temperature. It provided thetheory basis for water-system’s design and the automatic control system.The evaporative cooling and mechanical refrigeration compound high temperaturechiller complete first practice in a buildingin medium humidity area xian.The chiller canrun switch mode of separately evaporative cooling section, evaporative cooling section andmechanical refrigeration section function at the same time or run separately mechanicalrefrigeration section running according to outdoor air condition change realize,to make fulluse of dry air of air conditioning operation period with low energy for the objective ofenergy-saving. This chiller compared with air source heat pump under the samerefrigerating capacity (140KW), during8:00～18:00every day of June to September inxian, the period of time of running separately evaporative cooling section is occupied43%,can save14019.3kWh power, equivalent to save5.61tons standard coal every year, equivalent to reduce CO2emissions by13.97tons, and save7009.7yuan peration cost withenvironmental protection per year (0.5yuan/degrees).In allusion to the test analysis of using the indirect-direct evaporative cooling waterchiller of a certain power plant office of dry areas Wu CaiWan shows that: in the testrange(26.5℃≤tg≤37.3℃;20.5℃≤tS≤26.1℃;16.3℃≤tL≤23.6℃),the output watertemperature of the indirect-direct evaporative cooling water chiller is between the wet bulbtemperature and the dew point temperature of the fresh air (outdoor air),the value of coldhigh increases with the increase of the difference between dry bulb and wet bulbtemperature,dry bulb and dew point temperature,and wet bulb and dew point temperatureof outdoor air,and shows increasing tendency; however the value of cold deep relativelystable, in2～3℃scope fluctuations. Therefore,should use the parameters of the cold deeprepresent the output water temperature characteristic of the indirect-direct evaporativecooling water chiller.In allusion to the test analysis of using the compound high temperature water chillerof evaporative cooling and mechanical refrigeration of a certain office building of mediumhumidity areas Xi·an shows that: in the test range（26.5℃≤tg≤37.3℃；20.5℃≤tS≤26.1℃；16.3℃≤tL≤23.6℃）,the output water temperature of the unit is between the wet bulbtemperature and the dew point temperature of the fresh air (outdoor air),the maxdifference between wet bulb and dew point temperature is5℃. the value of cold highincreases with the increase of the difference between dry bulb and wet bulb temperaturedry bulb and dew point temperature and wet bulb and dew point temperature of outdoorair,which relatively large fluctuation,in0.3～3℃scope fluctuation,however the change ofthe deep cold picture more quietly, and in the2～3℃range.