小型全封闭活塞式制冷压缩机稳态仿真

本文提出了小型全封闭活塞式压缩机稳态模型,并对其性能参数进行了仿真,仿真值与试验值的误差在5%以内,表明所建立的压缩机稳态模型合理,这对研究制冷系统的调节和控制有很大的帮助.     

螺杆式与活塞式制冷压缩机的比较

以萨布罗公司(SABROE)的产品为例,在容积效率、运行费用、绝热效率、COP值、部分载荷、电动机效率、冷量调节、制冷剂、维修检查及市场前景等方面对应用最为广泛的活塞式压缩机及螺杆式压缩机进行了评价,从而为压缩机的选择提供了一些参考依据。     

活塞式压缩机排气量的现场测量

对活塞式压缩机排气量的各种测量方法进行了分析比较，着重介绍了比较适合于现场测量的孔板节流装置，并结合现场测量实例指出了压缩机排气量现场测量应注意的问题。     

滚动活塞式旋转压缩机的振动

在日本,滚动活塞式旋转压缩机广泛用于空调器及冰箱。与往复式压缩机比较,其性能优良,造价低,尺寸小,重量轻。然而从振动的角度来看,旋转压缩机就不那么有吸引力了,因为其悬挂系统不同。通常,往复式机组的压缩机部件和电机部件都由封闭壳内的悬挂弹簧所支撑,而机壳又由机座上的悬挂弹簧(或橡胶垫)支撑。在旋转压缩机中,由于其压缩机构的振动相当小,取消了内悬挂弹簧,仅由单一的外悬挂系统支撑。     

用于离心式高温热泵机组研发的模拟模型

为了对所设计的高温热泵机组中各设备进行合理匹配,建立其稳态模拟模型。该模型包括关键部件的子模型:带有经济器的双级离心式压缩机、卧式壳管式冷凝器、浮球膨胀阀、满液式蒸发器和回热器。在模拟算法的设计中,将模块化方法与二分法相结合,所需输入参数易于为设计者所获得,且不会限制系统的运行。利用该模型,对高温热泵进行初步设计;经过多方案比较,确定各换热器的结构参数,并预测该系统的性能和运行参数。     

低温热泵用涡旋压缩机性能的试验研究

制定低温热泵用涡旋压缩机试验方案,对研制的原型机进行性能测试。试验结果表明：在冷凝温度不变的情况下,随着蒸发温度的降低,原型机的制热量有所减少,但减少的速度低于普通热泵系统用涡旋压缩机;压缩机的电功率有所增加,但增加的幅度不大,且压缩机的排气温度也有所降低,故在低温工况下采用准二级压缩热泵用涡旋压缩机比采用普通热泵用涡旋压缩机可以更有效地提高空气源热泵的低温制热性能,是寒冷地区用小型空气源热泵比较适宜采用的压缩机。     

Defrost cycle performance for an air-source heat pump with a scroll and a reciprocating compressor

A 10.6 kW nominal cooling capacity air-source heat pump was tested according to ANSI/ASHRAE Standard 116-1983 for the frost acumulation and defrost cycle. These tests required indoor conditions of 21.1°C (70°F) dry-bulb, 15°C (60°F) maximum wet-bulb, with outdoor conditions of 1.7°C (35°F) dry-bulb, 0.5°C (30°F) wet-bulb. The unit was tested with the original scroll compressor and a reciprocating compressor that yielded similar heating performance. Heating capacity for the scroll system peaked at 8.4 kW (2.38 tons), while the reciprocating system heating capacity peaked at 8.5 kW (2.42 tons) during the frosting period. Heating capacities for the two system configurations differed by less than 1% during the frosting period. Power demand for the scroll system peaked at 2.9 kW, and the reciprocating system power demand peaked at 3.1 kW. During the frosting period, the reciprocating system power demand averaged 7% higher than the scroll system power demand. The reciprocating system completed a defrost 5% faster than the scroll system. Scroll system defrost time was 6.8 min while reciprocating system defrost time was 6.5 min. The volume of condensate produced differed by less than 3% with 1680 ml (102.5 in³) and 1640 ml (100 in³) produced by the scroll and reciprocating systems, respectively. Discharge pressures during defrost were within 3% with peak values of 1315 kPa (191 psia) and 1351 kPa (196 psia) for the scroll and reciprocating systems respectively. The reciprocating compressor produced higher levels of discharge superheat, peaking at 53°C (95°F) compared to the scroll system peak discharge superheat of 47°C (85°F). Overall, discharge superheat for the reciprocating system averaged 18% higher than the scroll system. The reciprocating system produced defrost refrigerant flowrates that averaged 3% higher than the scroll system. Refrigerant flowrates for the scroll and reciprocating systems peaked at 3.7 kg min⁻¹ (8.2 lbm min⁻¹) and 4.0 kg min⁻¹) (8.8 lbm min⁻¹) respectively.     

两级压缩式热泵空调与冰箱复合系统

根据两级压缩式制冷原理和热泵空调与冰箱制冷系统运行工况的不同,提出一种新型两级压缩式热泵空调与冰箱复合系统,介绍其原理及不同工况模式下的实现方式。该系统将热泵空调系统与冰箱系统冷热量相互有效利用,具有节能效果。对一个应用实例进行数值模拟,结果表明：复合系统能耗与常规的各自独立系统的总耗能相比,冬季节能约9％,夏季节能约18％。     

换热因素对空气源热泵热水器压缩机运行范围影响探讨

简要分析空气源热泵热水器系统运行对压缩机运行范围的影响,由于换热特性和热泵系统热力特性的限制,在低温运行条件下,冷凝温度将不超过65℃;而提高压缩机蒸发温度上限的措施,仍然不能免除在夏季运行采取防止蒸发温度过高的措施.在技术措施正确的前提下,空调压缩机可以满足空气源热泵热水器的应用要求.本文指出,我国标准中规定20℃为空气源热泵热水器额定运行进风温度是不合理的,客观上对行业发展产生了不良影响;目前市场上存在的产品质量问题,主要原因是受标准的影响和系统设计的技术措施不当,并非压缩机性能问题.     

A general model for two-stage vapor compression heat pump systems

Two-stage vapor compression technology has high potential of performance improvement for cold climate heat pumps, and there are several types of inter-stage configurations that need to be evaluated before making a choice. A general model of these configurations is first derived from a subcooler cycle and then is extended to be capable of evaluating many other inter-stage configurations by employing an “input domain”. The model is solved with a sequential algorithm and an analytical initial solution of the intermediate pressure is presented. After an experimentally validation with additional calculations of the subcooling parameter, the evaporating and condensing pressure, this general model is then used in the performance comparison and analysis of eight different inter-stage configurations. At last, case studies show that, this general model is capable of performing performance comparison among cycles with different types of inter-stage configurations, as well as refrigerant selection and operational analysis.     

螺杆式空气源热泵机组压缩机油位试验研究

分析压缩机吸气回液、外置油分离器油分离效率对螺杆式空气源热泵机组压缩机油位的影响,提出改进翅片换热器分液、优化气液分离器结构、改善油分离器分离方式等改进措施,并对螺杆式空气源冷（热）水机组进行试验。结果表明,所提改进措施不仅能够提高压缩机运行过程中的油位,而且能够提高机组运行稳定性。     

土壤源热泵水平螺旋地埋管换热器换热性能研究

通过建立水平螺旋地埋管与回填材料以及土壤的三维换热数学模型,对水平螺旋地埋管换热器的换热性能进行研究。对影响水平螺旋地埋管与土壤之间换热性能的因素进行分析,包括水的流速、进口水温、螺旋环径、相邻环中心间距、回填材料等。研究结果表明这些影响因素对换热性能（单位管长换热量和单位土壤长度换热量）有着不同程度的影响。     

直线压缩机驱动的超高温双作用行波热声热泵

提出了一种直线压缩机驱动下的高温双作用行波热声热泵流程,并以kW级别的热泵系统进行了设计和优化。在热泵热端温度为150℃,环境温度为40℃时,计算模拟了其在不同回热器结构以及不同换热器结构下的性能。得出当回热器采用板叠式回热器,换热器采用管壳式换热器时能够获得较高的效率和较大的泵热量,获得的热端泵热量可达1 823.9 W,热泵系数COP为3.16,相对卡诺效率为82.3%。在此基础上,进一步计算了热泵在不同环境温度和不同热端温度下的工作性能,以模拟工业上热泵在不同环境下的工作状况。     

涡旋压缩机在热泵热水器中的应用

热泵热水器以制取热水为目的，有别于普通制冷或空调设备。热泵热水器运行时冷凝温度和冷凝压力很高，对压缩机的可靠性和应用技巧提出了较高要求。涡旋压缩机以其可靠性好、效率高，在热泵热水器中得到了大量应用。