In the field of heat pumps,there are a number of parameters that affect the performance and efficiency of the apparatus,which have been the subject of studies by individual researchers in the literature.This study des...In the field of heat pumps,there are a number of parameters that affect the performance and efficiency of the apparatus,which have been the subject of studies by individual researchers in the literature.This study describes an experimental method in order to investigate the effects of some significant parameters on heat pump performance.In this regard,a laboratory heat pump setup has been utilized to operate in different working conditions for achieving an appropriate estimation to find out effects of mentioned parameters such as refrigerant type and charge amount,compressor oil viscosity,compressor cooling fan,secondary fluids temperature and flow rate.Different refrigerants have been selected and used as circulating fluid in the installed heat pump.Although this work has been devoted to a detailed attempt to recognize the effects of various parameters on the coefficient of performance(COP) value,an appropriate method has been carried out to survey the obtained results by using economic analysis.It was revealed that one of the main parameters is refrigerant charge amount which has a notable effect on COP.The temperature of the heat source was also tested and the performance of the system increased by more than 11% by employing mentioned modifications and various operating conditions.In addition,by selecting a low viscosity compressor oil,the system performance increased by 18%.This improvement is more than 6% for the case that cooling fan is installed to cool the compressor element.展开更多
为探索多能互补的清洁能源供暖技术,满足北京市村镇分散式建筑清洁供暖需求,在北京农村地区建设太阳能-地源热泵复合式系统,进行太阳能补热热泵供暖实验,并利用COMSOL软件开展地温场热均衡模拟研究。结果表明:相较单一地源热泵系统,太...为探索多能互补的清洁能源供暖技术,满足北京市村镇分散式建筑清洁供暖需求,在北京农村地区建设太阳能-地源热泵复合式系统,进行太阳能补热热泵供暖实验,并利用COMSOL软件开展地温场热均衡模拟研究。结果表明:相较单一地源热泵系统,太阳能补热热泵供暖方案下,地源侧出水温度提升23%,系统制热能效比(Coefficient of Performance,COP)和机组COP分别提升19%、25%;系统运行10 a,地源热泵系统单季节运行方案下总的取热量要多于间歇期自然恢复量,地温场总均衡为-8.91×10^(9)kJ;单一地源热泵方式运行和太阳能补热方式运行在双季节情况下总的取热量小于总的排热量,地温场总均衡分别为4.220×10^(9)、1.084×10^(10)kJ。因此,双季节运行方案对地温场不会产生负均衡,反而会对地温场有一定的热量补充。地源热泵系统运行中加入太阳能补热,对地温场的影响更小,可显著提升系统和机组效率,该模式适用于北京农村地区特别是供暖需求较大的建筑。展开更多
针对电动汽车冬天取暖能耗较高,设计了基于蒸气压缩循环的热泵空调试验系统,研究了制热模式下不同的环境温度和压缩机转速对车室内平均温度、高压管路内部工质的温度和压力、系统能效比(COP,Coefficient of Performance)等参数的影响....针对电动汽车冬天取暖能耗较高,设计了基于蒸气压缩循环的热泵空调试验系统,研究了制热模式下不同的环境温度和压缩机转速对车室内平均温度、高压管路内部工质的温度和压力、系统能效比(COP,Coefficient of Performance)等参数的影响.试验结果表明,当环境温度和压缩机的转速较高时,压缩机出口、车室内换热器出口处工质的温度和压力值较大,车室内平均温度的上升速度越快,达到舒适温度所需的时间越短.在压缩机转速相同时,环境温度越高,系统的COP值越大.展开更多
对有机朗肯-蒸汽压缩复合式热泵系统的循环原理进行了描述,建立了系统性能的计算模型.其系统优势在于结构紧凑,能小型化,这使得采用太阳能驱动的家用小型空调成为可能;且性能系数相对较高,吸收式的制冷系数(coefficient of performance,...对有机朗肯-蒸汽压缩复合式热泵系统的循环原理进行了描述,建立了系统性能的计算模型.其系统优势在于结构紧凑,能小型化,这使得采用太阳能驱动的家用小型空调成为可能;且性能系数相对较高,吸收式的制冷系数(coefficient of performance,COP)小于0.7,而有机朗肯-蒸汽压缩复合式热泵系统的制冷COP理论上高于1.4,且在室外温度越高时系数越高;能实现机械能、冷量的切换输出,在制冷工况和制热工况下,对有机朗肯循环和热泵循环采用相同工质和不同工质的循环性能进行了比较计算,筛选出了复合系统最适宜的工质,为进一步设计有机朗肯-蒸汽压缩式热泵系统提供理论指导,使此复合式热泵系统的应用成为可能.展开更多
为探究压缩机的倒置性能,搭建性能实验台,研究制冷剂充注量对制冷性能的影响。结果表明:当制冷量及其他条件一定时,随着充注量的增加,压缩机排气温度和功率大于正立的值,制冷COP(coefficient of performance)小于正立的值。最佳制冷剂...为探究压缩机的倒置性能,搭建性能实验台,研究制冷剂充注量对制冷性能的影响。结果表明:当制冷量及其他条件一定时,随着充注量的增加,压缩机排气温度和功率大于正立的值,制冷COP(coefficient of performance)小于正立的值。最佳制冷剂充注量150 g下的最大制冷COP值为3.2。压缩机倒置后系统性能良好,该系统是"重力无关"系统。压缩机倒置性能实验可为热泵空间应用提供实验参考价值。展开更多
文摘In the field of heat pumps,there are a number of parameters that affect the performance and efficiency of the apparatus,which have been the subject of studies by individual researchers in the literature.This study describes an experimental method in order to investigate the effects of some significant parameters on heat pump performance.In this regard,a laboratory heat pump setup has been utilized to operate in different working conditions for achieving an appropriate estimation to find out effects of mentioned parameters such as refrigerant type and charge amount,compressor oil viscosity,compressor cooling fan,secondary fluids temperature and flow rate.Different refrigerants have been selected and used as circulating fluid in the installed heat pump.Although this work has been devoted to a detailed attempt to recognize the effects of various parameters on the coefficient of performance(COP) value,an appropriate method has been carried out to survey the obtained results by using economic analysis.It was revealed that one of the main parameters is refrigerant charge amount which has a notable effect on COP.The temperature of the heat source was also tested and the performance of the system increased by more than 11% by employing mentioned modifications and various operating conditions.In addition,by selecting a low viscosity compressor oil,the system performance increased by 18%.This improvement is more than 6% for the case that cooling fan is installed to cool the compressor element.
文摘为探索多能互补的清洁能源供暖技术,满足北京市村镇分散式建筑清洁供暖需求,在北京农村地区建设太阳能-地源热泵复合式系统,进行太阳能补热热泵供暖实验,并利用COMSOL软件开展地温场热均衡模拟研究。结果表明:相较单一地源热泵系统,太阳能补热热泵供暖方案下,地源侧出水温度提升23%,系统制热能效比(Coefficient of Performance,COP)和机组COP分别提升19%、25%;系统运行10 a,地源热泵系统单季节运行方案下总的取热量要多于间歇期自然恢复量,地温场总均衡为-8.91×10^(9)kJ;单一地源热泵方式运行和太阳能补热方式运行在双季节情况下总的取热量小于总的排热量,地温场总均衡分别为4.220×10^(9)、1.084×10^(10)kJ。因此,双季节运行方案对地温场不会产生负均衡,反而会对地温场有一定的热量补充。地源热泵系统运行中加入太阳能补热,对地温场的影响更小,可显著提升系统和机组效率,该模式适用于北京农村地区特别是供暖需求较大的建筑。
文摘针对电动汽车冬天取暖能耗较高,设计了基于蒸气压缩循环的热泵空调试验系统,研究了制热模式下不同的环境温度和压缩机转速对车室内平均温度、高压管路内部工质的温度和压力、系统能效比(COP,Coefficient of Performance)等参数的影响.试验结果表明,当环境温度和压缩机的转速较高时,压缩机出口、车室内换热器出口处工质的温度和压力值较大,车室内平均温度的上升速度越快,达到舒适温度所需的时间越短.在压缩机转速相同时,环境温度越高,系统的COP值越大.
文摘对有机朗肯-蒸汽压缩复合式热泵系统的循环原理进行了描述,建立了系统性能的计算模型.其系统优势在于结构紧凑,能小型化,这使得采用太阳能驱动的家用小型空调成为可能;且性能系数相对较高,吸收式的制冷系数(coefficient of performance,COP)小于0.7,而有机朗肯-蒸汽压缩复合式热泵系统的制冷COP理论上高于1.4,且在室外温度越高时系数越高;能实现机械能、冷量的切换输出,在制冷工况和制热工况下,对有机朗肯循环和热泵循环采用相同工质和不同工质的循环性能进行了比较计算,筛选出了复合系统最适宜的工质,为进一步设计有机朗肯-蒸汽压缩式热泵系统提供理论指导,使此复合式热泵系统的应用成为可能.
文摘为探究压缩机的倒置性能,搭建性能实验台,研究制冷剂充注量对制冷性能的影响。结果表明:当制冷量及其他条件一定时,随着充注量的增加,压缩机排气温度和功率大于正立的值,制冷COP(coefficient of performance)小于正立的值。最佳制冷剂充注量150 g下的最大制冷COP值为3.2。压缩机倒置后系统性能良好,该系统是"重力无关"系统。压缩机倒置性能实验可为热泵空间应用提供实验参考价值。