R417A和R22用于空气源热泵热水器的试验研究

对R417A和R22用于空气源热泵热水器进行试验,并在不同进水温度下对吸排气压力、吸排气温度、消耗功率、制热功率、热效率等方面进行对比分析。结果表明,混合工质R417A用于热泵热水器时,排气压力、输入功率低于R22的,制热功率易受水温影响,制热量低于R22的,性能系数下降迅速,但平均性能系数比R22的略高。     

Modeling evaluation of a direct-expansion solar-assisted heat pump water heater using R410A

A direct-expansion solar-assisted heat pump (DX-SAHP) system by using R410A as refrigerant is described, which can supply domestic hot water during the whole year. Based on the distributed parameter and homogeneous flow models of collector/evaporator and condenser, the lumped parameter models of compressor and electronic expansion valve, and the refrigerant charge model, a numerical model is developed to estimate the thermal performance of the system. Given the structure parameters, meteorological parameters, initial and final water temperatures, for a fixed superheat degree, the effects of the refrigerant charge quantity on the performance parameters of the system are analyzed, such as compressor power, heat gain of collector, heating time, collector efficiency and system COP. Furthermore, for a fixed refrigerant charge quantity, the effects of various parameters, including solar radiation, ambient temperature, compressor speed and initial water temperature, have been simulated and analyzed on the thermal performance of the system.     

R32空气源热泵热水器的实验研究

为了解 R32 和 R410A 制冷剂应用于空气源热泵热水器时的性能优劣,采用同轴套管换热器与空调室外机组相匹配,使用电子膨胀阀作为节流装置,在国标GB/T 23137-2008 规定下实验测试 R32 和R410A 在同一套空气源一次加热式热泵热水器样机上的性能.实验结果表明,R32 的充注量仅为 R410A 充注量的74%左右;在各种实验条件下,R32 空气源热泵热水器的能效比不低于 R410A 系统;在3℃低温环境下,R32 样机的性能系数提高31.1%,但排气温度达到101.9℃.不利于 R32 制冷剂在低温条件下的应用;因容积制热量较大,在相同设计能力下 R32 压缩机的排气量可以比 R410A 系统降低4.5%.     

On-field measurement method of vapor injection heat pump system

This paper examines air-to-air injection heat pumps (HPs) and proposes a method to determine both heating capacity and coefficient of performance (COP) in situ, allowing analyses of already-installed setups and long-term observation. Due to the uncertain nature of air enthalpy measurements, this method instead uses refrigerant enthalpies calculated from pipe contact temperatures and steady-state energy balances to determine the COP. However, these energy balances are highly dependent on the hypothesis that the working fluid remains strictly monophasic in certain locations, which is not always true in practice. A parametric variable analysis is conducted on the refrigerant vapor quality to calculate the deviation in the COP due to diphasic conditions at the compressor inlet, injection port, and condenser and flash tank outlets. A final in situ COP uncertainty is presented, due to both the measurement and vapor quality uncertainties.     

低温工况下空气源热泵热水器中R22与R417性能对比

在低温环境下,研究了R22与R417A对空气源热泵热水器的性能影响。得出了机组性能系数(COP)、制热量、排气压力、压缩机功率和水箱水温与加热时间的关系。     

Transient thermal behavior of a water heater system driven by a heat pump

A dynamic model of a water heater system driven by a heat pump was designed to investigate transient thermal behavior of the system which was composed of a heat pump and a hot water circulation loop. Finite volume method was applied to describe the heat exchangers, and lumped parameter models were used to analyze the compressor and the hot water reservoir. Dynamic performances were evaluated as the hot water temperature changes for various sizes of the hot water reservoir. In order to compare the performance characteristics, time scale was normalized by the time constant determined from a quasi-steady state simulation of the system. From the simulation, the smaller size of the water reservoir was found to have larger transient performance degradation, and the larger size caused additional heat loss during the hot water storage period. Therefore, the reservoir size should be optimized in a design process to minimize both the heat loss and the performance degradation.     

R290空气源热泵热水器的试验研究与对比

为了研究R290和R22在空气源热泵热水器上的性能,试验样机采用一套同轴式套管换热器（与某空调室外机组相匹配连接）和1个电子膨胀阀（安装在2个换热器之间）,根据国标GB/T23137—2008测试R290和R22在该样机上一次性加热热水的各种性能。试验结果表明,R290的充注量仅为R22的42%~46%;在各种试验条件下,R290的能效比不低于R22的,压缩比低且排气温度更低;R290压缩机排量需要比R22系统提高15.4%。     

Performance evaluation of a vapor injection heat pump system for electric vehicles

Battery-powered electric vehicles (EV) need an efficient electric heating system for extending the driving mileage. An air-source heat pump system offers an economical alternative for EV because it consumes less energy than a heating system using Joule heat and it can use the same components as an air conditioning system for cooling. However, its performance degradation is inevitable at very low ambient temperatures. Although vapor refrigerant injection is known as a good technology to overcome this problem in residential heat pump systems, the number of vapor injection heat pump studies for EV applications is quite limited. In this paper, considering the characteristics of EV application, the configuration of a vapor injection heat pump system for EV is introduced, and it was modeled, using a scroll compressor geometry-based thermodynamic analysis. The performance was estimated for cold ambient regions under the EV operational conditions.     

空气源热泵热水器系统性能分析

为了预测空气源热泵热水器的运行性能,提高系统稳定性和降低能耗,建立空气源热泵热水器系统仿真模型,在焓差实验室对一台水箱容积为150L的一体式空气源热泵热水器样机进行变工况实验以验证模型的准确性,利用所建立的模型研究蒸发器入口空气流速及制冷剂质量流量对机组性能的影响。结果表明:系统制热量和COP都随环境温度的升高而不断增大;系统制热量随蒸发器入口空气流速的增大而呈增大趋势,在达到某值后,系统制热量变化趋于稳定;系统COP随制冷剂质量流量的不断增加呈先增大后减小的趋势,即制冷剂质量流量存在最佳值使得热泵性能系数最高。     

空气源热泵热水系统动态建模研究

从理论的角度分析空气源热泵热水系统动态建模研究的可行性,介绍建立动态模型的初步思路.最后结合几个例子总结分析在空气源热泵热水系统中运用动态建模技术的实际节能意义.     

跨临界CO2热泵热水系统试验研究

对跨临界CO2水-水热泵多种工况的循环性能进行试验研究,获得一系列试验数据。试验结果表明,1）跨临界CO2热泵循环在高温热泵领域可得到高于常规热泵系统的制热系数;2）降低气体冷却器出口温度,提高蒸发温度,选择最佳的高压侧压力可有效提高系统的制热系数。最后根据试验结果为今后CO2热泵流程设计提出一些建议。     

热泵热水机的设计和工程应用

从节能和高效的观点出发,分析热泵热水机产品的效率和产品的设计要点;在工程应用方面,提出综合应用的方法,表明热泵热水机在提供生活热水和空调方面具有显著的节能效果。     

空气源热泵冷热水机组的故障珍断

研究了基于BP模型神经网络的故障诊断方法，它只需来自生产实际的大量样板实例或领域专家的知识训练神经网络。由于其具有容错性，训练好神经网络不仅能诊断出已经出现过的故障，还能在一定范围内诊断出从未出现过的故障；仿真结果表明，基于人工神经网络的空气源热泵冷热水机组的故障诊断是行之有效的。     

关于热泵热水机出水温度的探讨

分析热泵热水机出水温度确定的影响因素,认为主要考虑卫生问题和节能性。通过总结国内外相关标准、规范、手册等技术资料,认为60℃是比较合理的出水温度。同时指出,CO2作为热泵热水机制冷剂可以使机组出水温度和性能均获得提升,是热泵热水机产品升级的理想选择。     

Measurements of the surface tension for R290, R600a and R290/R600a mixture

The surface tensions of R290, R600a and R290/R600a mixture have been measured by the modified differential capillary-rise method. Twenty-two data points for R290 and 21 data points for R600a were obtained in the temperature range between 273 K and 354 K, and 43 data points for R290/R600a mixture on three isotherms of 278 K, 300 K and 320 K were obtained. The experimental uncertainties of temperature and surface tension are estimated to be within 20 mK and 0.2 mN m⁻¹, respectively. Surface tension correlations as a function of temperature for pure R290 and R600a were formulated in the temperature range between 253 K and critical temperature, and the correlation as a function of the composition for R290/R600a mixture was discussed at 278 K, 300 K and 320 K. It is found that the surface tension for R290/R600a mixture can be reproduced by the simple mixing rule by mole fraction with the correlations of both pure components.     

R125/R290及R125/R600a热泵工质适用温区探究

循环温升保持45℃,热源进口温度范围为10—45℃的热泵工况下,建立了基于控制换热器窄点温差的热泵循环模型,对小温度滑移混合工质R125/R290(质量配比25/75)及大温度滑移工质R125/R600a(质量配比10/90)的热泵循环性能分别进行了分析研究。发现R125/R290制热循环性能系数COPh随名义蒸发温度的升高而提高,而对于R125/R600a,COPh却变化平缓。同时两种混合工质的排气温度和冷凝压力均在系统安全运行范围之内。结果表明:对于小温度滑移工质R125/R290更适合于低温热源工况,大温度滑移工质R125/R600a则更适用于高温热源工况。     

CO_2工质在热泵热水机中的应用

通过对CO2工质的特性进行分析和实验验证,探讨了CO2工质在热泵热水机中应用的可行性、优缺点、前景以及所面对的困难等,希望对CO2工质应用于热泵热水机起到促进作用。     

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。     

制冷剂R32特性及其用于空气源热泵热水器的理论循环分析

介绍R32,R22和R407C以及R410A四种制冷剂的流动特性和热力学特性,并对采用这4种制冷剂的空气源热泵热水器进行理论循环分析。从计算结果可以看出,与采用其他3种制冷剂的系统对比,采用R32制冷剂的系统具有较低的压缩比,较高的理论COP以及容积制热量;在当前阶段,R32是用于空气源热泵热水器的一种较好的制冷剂。     

直热式热泵热水机组的开发初探

简要介绍直热式热泵热水机组的开发背景、应用前景、使用优点等,根据实际开发经验,对开发过程中的水温控制问题、除霜问题、高温制热问题等重点难点进行方向性分析,为直热式空气源热泵热水机的开发提供一些思路。