基于冷却塔逆用的热泵制热系统分析
|
摘要
冷却塔逆用已经在热泵制热系统中得到实际应用并取得了一定的节能效果。本文从热力学第二定律的角度,对冷却塔逆用作为低温热源的热泵制热系统进行了分析。构建了系统各部件分析数学模型,并结合实验系统现场测试数据进行分析,分析过程中采用损失、效率、损失率、损失系数评价指标综合评价。结果表明在系统制热工况下,末端空气处理机组与压缩机损失、损失率明显高于整个系统中其他设备及部件,损失率分别为14%和12%,是整个系统改进的主要对象。该研究有助于诊断出系统主要设备的薄弱环节,并能对系统的节能潜力做出判断,为进一步优化系统指明方向。
A mechanical draft cooling tower may be reversibly used,as part of a heat pump system for service hot water,to extract free heat from ambient air.It is advantageous in minimizing the total installation and operating cost.The research focused on the analysis and the evaluation of the exergy performance of the heating system and its components.The second law of thermodynamics performance analysis,also called the exergy performance analysis,can point out the inefficient components of the system with great improvement potential more accurately.And experimental study of a heat pump system is presented,and the analytical formulas of exergy loss,exergy efficiency,exergy loss rate and exergy loss coefficient were derived,respectively.According to the comparison,the most exergy is consumed by the AHU and the compressor,whose exergy destruction ratios are about 14% and 12%,respectively.To achieve better whole system's exergy performance,the recommend improvements should focus on these two kind of components.Furthermore,the results can draw an engineer's attention towards the components where the most availability is being destroyed and quantify the extent to which modification of one component affects,favorably or unfavorably,the performance of other components of the system.
A mechanical draft cooling tower may be reversibly used,as part of a heat pump system for service hot water,to extract free heat from ambient air.It is advantageous in minimizing the total installation and operating cost.The research focused on the analysis and the evaluation of the exergy performance of the heating system and its components.The second law of thermodynamics performance analysis,also called the exergy performance analysis,can point out the inefficient components of the system with great improvement potential more accurately.And experimental study of a heat pump system is presented,and the analytical formulas of exergy loss,exergy efficiency,exergy loss rate and exergy loss coefficient were derived,respectively.According to the comparison,the most exergy is consumed by the AHU and the compressor,whose exergy destruction ratios are about 14% and 12%,respectively.To achieve better whole system's exergy performance,the recommend improvements should focus on these two kind of components.Furthermore,the results can draw an engineer's attention towards the components where the most availability is being destroyed and quantify the extent to which modification of one component affects,favorably or unfavorably,the performance of other components of the system.
引文
[1]Tan K X,Song Z Y,Deng S M.Service hot water supply usingcentral air conditioning systems for buildings in subtropics[M].Beijing:China Machine Press,1998
[2]宋应乾,马宏权,龙惟定.能源塔热泵技术在空调工程中的应用于分析[J].暖通空调,2011,41(4):20-23
[3]张晨,杨洪梅,刘秋克,等.开式热源塔在热泵系统中的应用分析[J].能源研究与信息,2010,26(1):52-56
[4]文先太,梁彩华,张小松.过渡季节冷却塔辅助供热的理论分析与研究[J].暖通空调,2011,41(2):90-93
[5]文先太,梁彩华,张小松,等.热源塔传质特性的分析和实验研究[J].化工学报,2011,62(4):901-907
[6]Tan K X,Deng S M.A method for evaluating the heat and masstransfer characteristics in a reversibly used water cooling tower(RUWCT)for heat recovery[J].International Journal of Refriger-ation,2002,25(5):552-561
[7]Tan K X,Deng S M.A numerical analysis of heat and mass transf-er inside a reversibly used water cooling tower[J].Building andEnvironment,2003,38(1):91-97
[8]Wu J S,Zhang G Q,Zhang Q,et al.Experimental investigation ofthe performance of a reversibly used cooling tower heating syste-m using heat pump in winter[A].In:Proceedings of the APPEE-C,Asia-Pacific[C].IEEE,2011
[9]Wu J S,Zhang G Q,Zhang Q,et al.Artificial neural networkanalysis of the performance characteristics of a reversibly usedcooling tower under cross flow conditions for heat pump heatingsystem in winter[J].Energy and Buildings,2011,43(7):1685-1693
[10]Tan K X,Deng S M.A simulation study on a water chiller compl-ete with a desuperheater and a reversibly used water coolingtower(RUWCT)for service hot water generation[J].Buildingand Environment,2002,37(7):741-751
[11]Wang X H,Bi Y H,Zhang H.Exergy ayalysis of GSHP[J].ActaEnergiae Solaris Sinica,2009,30(6):732-737
[2]宋应乾,马宏权,龙惟定.能源塔热泵技术在空调工程中的应用于分析[J].暖通空调,2011,41(4):20-23
[3]张晨,杨洪梅,刘秋克,等.开式热源塔在热泵系统中的应用分析[J].能源研究与信息,2010,26(1):52-56
[4]文先太,梁彩华,张小松.过渡季节冷却塔辅助供热的理论分析与研究[J].暖通空调,2011,41(2):90-93
[5]文先太,梁彩华,张小松,等.热源塔传质特性的分析和实验研究[J].化工学报,2011,62(4):901-907
[6]Tan K X,Deng S M.A method for evaluating the heat and masstransfer characteristics in a reversibly used water cooling tower(RUWCT)for heat recovery[J].International Journal of Refriger-ation,2002,25(5):552-561
[7]Tan K X,Deng S M.A numerical analysis of heat and mass transf-er inside a reversibly used water cooling tower[J].Building andEnvironment,2003,38(1):91-97
[8]Wu J S,Zhang G Q,Zhang Q,et al.Experimental investigation ofthe performance of a reversibly used cooling tower heating syste-m using heat pump in winter[A].In:Proceedings of the APPEE-C,Asia-Pacific[C].IEEE,2011
[9]Wu J S,Zhang G Q,Zhang Q,et al.Artificial neural networkanalysis of the performance characteristics of a reversibly usedcooling tower under cross flow conditions for heat pump heatingsystem in winter[J].Energy and Buildings,2011,43(7):1685-1693
[10]Tan K X,Deng S M.A simulation study on a water chiller compl-ete with a desuperheater and a reversibly used water coolingtower(RUWCT)for service hot water generation[J].Buildingand Environment,2002,37(7):741-751
[11]Wang X H,Bi Y H,Zhang H.Exergy ayalysis of GSHP[J].ActaEnergiae Solaris Sinica,2009,30(6):732-737