水源热泵热水器实验研究

水源热泵技术利用少量电能将地表水或地下水的低品位能量转移至高品位,目前正成为节能领域的研究热点.针对水源热泵变冷凝参数的相关研究缺乏的现状,通过搭建水源热泵热水器实验台进行了相应实验研究.在水流量Q为0.7~1.3 m~3·h~(-1),进水温度t为15~30℃范围内,对系统功耗、制热量、制冷量、热泵性能系数COP等参数进行了测量.实验结果表明,在水流量为1.1 m~3·h~(-1),进水温度为20℃时,COP达到最大值,系统平均热泵性能系数COP_(ave)为3.23,此时系统处于最佳运行工况.由此可知,寻找系统的最佳运行工况对热泵系统设计和实际工程应用具有重要的意义.     

直流变频空气源热泵热水器的实验研究

针对普通定频空气源热泵热水器不能在宽负荷和宽温度条件下运行等缺陷,提出一种直流变频空气源热泵热水器。通过对样机进行实验,得出了制热量、功率、COP值、吸气温度、排气温度等性能参数随压缩机运行频率的变化规律。结果表明直流变频热泵热水器能在宽负荷、宽温度条件下稳定运行。     

Experimental research and operation optimization of an air-source heat pump water heater

In order to optimize design and operation strategy of air-source heat pump water heater, an experimental set-up and simulation model were constructed. Also, a methodology of optimizing operation, which takes into account thermostatic and timing control patterns, was presented and applied. Experimental results indicated that the average COP ranged from 2.82 to 5.51 under typical conditions. The recommended outside area ratio of condenser coil to evaporator is 0.14−0.31 when the evaporator outside area is between 6.0 and 6.5 m² for this set-up. The optimal start-up time was between 12:00 and 14:00 if there was no electricity price difference between day and night, or it was near 22:00. The optimal setting water temperature should be adjusted according to the variation of seasonal ambient temperature. It was suggested that, based on this set-up, setting water temperature should be set higher than 46 °C in summer and 50 °C in other seasons.     

套管壁厚度对直热式空气源热泵热水器性能的影响

文章对不同套管内管壁厚度的直热式空气源热泵热水器的性能进行试验研究,分析了不同套管内管壁厚度对套管换热器的传热面积、水流速度、传热系数、水系统阻力和热泵热水器的制热量、能效比等的影响。对5台不同套管直热式空气源热泵热水器进行试验的结果表明,设计适当的套管内管壁厚度,不仅提高了热泵热水器的能效比,而且增大了制热量,降低耗电量。当套管内管壁厚度为0.7 mm时,热泵热水器的能效比最大。     

太阳能热泵热水器

目前,我国热水器市场上的主流产品包括燃气、电热和太阳热水器3类。燃气热水器具有价格低、加热快、出水量大、温度稳定等优点,社会拥有量达到3000多万台,约占市场份额的43％。但是,燃气热水器在使用中存     

Performance characterization of an indoor air source heat pump water heater for residential applications in Canada

Air source heat pump water heater (ASHPWH) is a relatively new addition to delivering hot water at reasonably high efficiency. ASHPWH systems have achieved significant acceptance for mild to warm climate regions where space heating is minimal or none. However, limited performance mapping is available on these water heaters in extreme cold climatic conditions, such as Canada. The paper has examined the long‐term performance of this technology in Canadian context. The investigation has established the performance characteristics of ASHPWH unit through a series of pre‐defined indoor tests and theoretical simulations. The coefficient of performance and other critical parameters of ASHPWH were established and discussed in detail. A model was developed, validated, and used to show the impact of such type of water heater on the overall energy consumption in the house. The results indicate that the summer cooling decreases and the winter heating increases in the house with an indoor ASHPWH unit. Nevertheless, the net effect leads to 21.3% reduction in the total electricity consumption of the house (space heating, cooling, and water heating). Research provided an accurate performance prediction of ASHPWHs for year‐round applications in Canadian homes.     

Integral-type solar-assisted heat pump water heater

An integral-type solar-assisted heat pump water heater (ISAHP) is designed and tested in the present study. The storage tank and the Rankine cycle unit are integrated together to make a more compact size. A thermosyphon loop is used to transfer the heat from the condenser to the water storage tank. The highest COP obtained in the tests is 3.83.     

Performance modeling of air cycle heat pump water heater in cold climate

Air (reverse Brayton) cycle has promising features in cold climate heat pump applications. In this study, an air cycle heat pump water heater (ACHPWH) simulation model considering the off-design performance of components was developed and validated with experimental data from literature. With this model, the performance of ACHPWH was numerically compared with two typical vapor compression heat pump water heaters (VCHPWH) under two different heating schemes, namely instantaneous heating and recirculation heating. For instantaneous heating, the COP of ACHPWH is comparable to that of VCHPWH when supplying high temperature water or operating at low ambient temperature. A significant improvement on annual performance would be achieved as well if higher efficient compressor and expander were applied in ACHPWH system. For recirculation heating, although the COP gap got larger, ACHPWH would save plenty of heating time when operating at low ambient temperature.     

Assessment of a heat pump water heater

We present results from a field study of a heat pump domestic hot water heater. The data demonstrate that the system was able to maintain a high standard of hot water service to all participants and in some cases actually improved the standard. The heat pump was able to realize annual average savings of 50–58 per cent when compared to conventional resistive water heaters. We also show that, in New Zealand, large scale application of this type of heat pump should become an economic alternative to the construction of new electrical generating capacity in the 1990s.     

空气源热泵热水器系统的模拟计算

空气源热泵热水器已经成为一种新兴的热水器形式,从压缩机、冷凝器、节流阀和蒸发器四大部件出发,建立了各自的数学模型,尤其对冷凝器和蒸发器,建立了精确度相对较高的稳态分布参数分段模型。并对系统稳态运行性能进行了模拟分析。主要探讨空气进口参数、冷却水进口参数和流量对系统的影响。结果表明。当冷却水进水温度为20℃,回水温度为50．5℃时,冷却水流量可达到1．8kg／min。系统制热系数可达4．2。可见,空气源热泵热水器是一种比较有前景的节能技术。     

Heat-pipe enhanced solar-assisted heat pump water heater

A heat-pipe enhanced solar-assisted heat pump water heater (HPSAHP) is studied. HPSAHP is a heat pump with dual heat sources that combines the performance of conventional heat pump and solar heat pipe collector. HPSAHP operates in heat-pump mode when solar radiation is low and in heat-pipe mode without electricity consumption when solar radiation is high. HPSAHP can thus achieve high energy efficiency. A prototype was designed and built in the present study. An outdoor test for a HPSAHP in the present study has shown that COP of the hybrid-mode operation can reach 3.32, an increase of 28.7% as compared to the heat-pump mode COP (2.58).     

某度假村水源热泵空调系统的设计方案选择与分析

通过对宁波银凤度假村空调系统的比较，分析了分体式水源热泵空调系统的优势并提出了对今后设计、施工中应注意的几点意见。     

空气源热泵热水器全生命周期碳排放研究

将全生命周期评价方法应用于空气源热泵热水器的碳排放研究,将其全生命周期分为生产、使用和报废处理3个阶段,计算其各个生命阶段碳排放。结果表明:在其全生命周期各个阶段中,使用阶段的碳排放在总排放中具有最大贡献,超过97%。生产材料的使用原本会引起较大的排放量,但由于回收利用抵消了大部分的二氧化碳排放,因此降低其碳排放的主要措施为提高能效和运行节能。     

空气源热泵冷热联供热水机组

一产品意义和背景近年来太阳热水器产业发展以年30%的速度递增,并有向我国南方地区加快推广的趋势,突出的如上海市。2000年太阳热水器开始进入上海市场,到2003年其在上海热水器市场中的占有率已达3.7%,且价格高达3000～6000元/套。然而,我国太阳能资源分布有着地区上的较大差异,南方大部分地区恰恰是全年太阳辐射总量<500万千焦/米2,也即全年的晴天率≤50%的地区,包括湖南、湖北、广西、江西、浙江、福建北部、广东北部、陕西南部、江苏南部、安徽南部、黑龙江、四川、贵州等地。据上海2000年～2002年气象统计资料(表1),其平均阴天加雨天占6…     

Experimental performance analysis and optimization of a direct expansion solar-assisted heat pump water heater

In this study, a direct expansion solar-assisted heat pump water heater (DX-SAHPWH) with rated input power 750 W was tested and analyzed. Through experimental research in spring and thermodynamics analysis about the system performance, some suggestions for the system optimization are proposed. Then, a small-type DX-SAHPWH with rated input power 400 W was built, tested and analyzed. Through exergy analysis for each component of DX-SAHPWH (A) and (B), it can be seen that the highest exergy loss occurs in the compressor and collector/evaporator, followed by the condenser and expansion valve, respectively. Furthermore, some methods are suggested to improve the performance of each component, especially the collector/evaporator. A methodology for the design optimization of the collector/evaporator was introduced and applied. In order to maintain a proper matching between the heat pumping capacity of the compressor and the evaporative capacity of the collector/evaporator under widely varying ambient conditions, the electronic expansion valve and variable frequency compressor are suggested to be utilized for the DX-SAHPWH.     

太阳能电池与热泵热水器联合运行系统性能分析

为了降低太阳能光伏电池的温度,同时提升热泵热水器的蒸发温度,利用循环水路冷却太阳能光伏电池,并将热量传递给热泵热水器的蒸发器,构成联合运行系统。针对杭州市的夏季和冬季气象条件,对该联合运行系统的性能进行了计算,分析了对应不同太阳能电池温度下的系统运行参数的变化情况,包括太阳能电池发电效率和所需换热量,热泵热水器的制热量以及热泵效率等。计算结果表明,该联合运行系统能够同时提高太阳能电池光伏转换效率和热泵效率。     

压缩式热泵热水器实验研究及性能分析

从压缩式热泵热水器的实验研究出发，对热泵热水器的性能参数进行了分析，通过与几种常用热水器技术和经济性的比较，对热泵热水器的进一步优化设计和改进提出了建议。     

Energy consumption modeling of air source electric heat pump water heaters

Electric heat pump air source water heaters may provide an opportunity for significant improvements in residential water heater energy efficiency in countries with temperate climates. As the performance of these appliances can vary widely, it is important for consumers to be able to accurately assess product performance in their application to maximise energy savings and ensure uptake of this technology. For a given ambient temperature and humidity, the performance of an air source heat pump water heater is strongly correlated to the water temperature in or surrounding the condenser. It is therefore important that energy consumption models for these products duplicate the real-world water temperatures applied to the heat pump condenser.This paper examines a recently published joint Australian and New Zealand Standard, AS/NZS 4234: 2008; Heated water systems – Calculation of energy consumption. Using this standard a series TRNSYS models were run for several split type air source electric heat pump water heaters. An equivalent set of models was then run utilizing an alternative water use pattern. Unfavorable errors of up to 12% were shown to occur in modeling of heat pump water heater performance using the current standard compared to the alternative regime. The difference in performance of a model using varying water use regimes can be greater than the performance difference between models of product.     

Long-term performance of solar-assisted heat pump water heater

A long-term reliability test of an integral-type solar-assisted heat pump water heater (ISAHP) was carried out. The prototype has been running continuously for more than 13,000 h with total running time >20,000 h during the past 5 yr. The measured energy consumption is 0.019 kWh/l of hot water at 57 ^oC that is much less than the backup electric energy consumption of the conventional solar water heater.     

水源热泵空调系统不同末端性能分析

以辽宁某医院的空调系统为例,对水源热泵分别与风机盘管及毛细管网联合运行的2种空调系统的运行能效进行对比研究。通过运行数据分析可知,制热时水源热泵与风机盘管系统COP为2.72,水源热泵与毛细管网系统COP为4.21;制冷时水源热泵与风机盘管系统COP为5.82,水源热泵与毛细管网系统COP为7.78。水源热泵与毛细管网末端联合运行的空调系统运行能效均高于水源热泵与风机盘管末端系统的运行能效,具有明显优越性。