Applicability Analysis Of Parabolic Trough Solar Collectors In Absorption Refrigeration And Hot Water Heating System In Different Regions

In recent years,using solar energy to supply cooling and heating for buildings has developed rapidly with the national call for energy conservation and emission reduction.Among all kinds of solar refrigeration methods,the parabolic trough solar collectors(PTCs)driving double-effect lithium bromide absorption refrigeration system has a high coefficient of performance(COP).Besides,PTCs with a plate heat exchanger can be used for domestic heating in winter.Accordingly,the the absorption refrigeration and hot water heating system with PTCs can meet the load demand both in winter and summer.In addition,the climatic conditions,solar resources and fossil energy prices in different regions are quite different,so it is important to analyze the applicability of PTCs in the absorption refrigeration and hot water heating system in different regions.Firstly,this paper introduces the absorption refrigeration and hot water heating system with PTCs and its operation modes in winter and summer.Mathematical models for PTCs and the afterburning gas double-effect lithium bromide absorption chiller are established and solved by the Matlab programming.To verify the accuracy,on-site tests of the system located in an office building in Tianjin are carried out.The deviations between the calculated and measured results are within reasonable limits,so the models can be used in the following analysis.Then,taking a typical office building in Tianjin as an example,the hourly load in winter and summer is calculated by the eQUEST software.The influence of factors on the performance of PTCs and the absorption chiller is studied,and the area of PTCs and major parts in the absorption chiller are calculated according to the design values respectively.Following that,this optimized system is compared with the cooling and hot water system with direct-fired engine.The economy of this system is evaluated by the index of static investment payback period.The energy saving and emission reduction of this system is evaluated by the indices of primary energy consumption,primary energy ratio and carbon dioxide emission.Finally,nine representative cities of China are selected with solar energy distribution regions and climatic regions.The static investment payback period,energy saving and emission reduction of the absorption refrigeration and hot water heating system with PTCs in these cities are investigated.The results show that:(1)the order of the system static investment payback period in different cities from short to long is listed as follow: Turpan,Haikou,Nanjing,Xiamen,Shijiazhuang,Hangzhou,Tianjin,Hechi,Chengdu;(2)the economy of this system is significantly affected by the collector price and fossil energy price;(3)this system can save energy and reduce emissions effectively in most cities.