少量R744对R290空气源热泵热水器性能影响的试验研究

发布时间：2018-01-07 19:17

本文关键词：少量R744对R290空气源热泵热水器性能影响的试验研究　出处：《中原工学院》2017年硕士论文　论文类型：学位论文

【摘要】：臭氧层空洞问题有所好转之际,全球气候变暖却在逐年加剧,在推进温室气体减排领域仍然面临着一场攻坚战。欧盟等发达国家已经开始通过立法来限制高全球变暖潜能值HFCs制冷剂的使用,零ODP、低GWP的自然工质又重新受到赏识。R744(CO2)属于低温高压制冷剂,在热泵制热水方面极具优势,但对设备的材料强度和配件密封性的要求更苛刻;R290(丙烷)的ODP为零,GWP仅为20,与R22相比,具有较低的蒸气压力和较高的汽化潜热,但易燃易爆是最大的安全隐患。基于各自特点,以R290为主要组分,R744作为加入组分,将R744/R290混合工质应用于空气源热泵热水器并展开深入研究。首先,在改造后的试验台上对R22制冷剂进行了试验测试,试验结果表明R22的充罐量在1.15kg时,系统的制热性能系数最大为4.176;其次,对R290制冷剂进行了直接灌注式替代试验,结果表明:R290系统的最佳充罐量为450g,其对应的制热性能系数最大为3.907。在R290系统的最优充罐量下,设定不同的膨胀阀开度进行了试验研究,结果表明:在脉冲开度300P时,R290系统的制热性能系数最大为4.251,较直接灌注式替代试验提高了8.8%;稍高于R22系统,并且充罐量仅为R22的39.1%。根据R290系统不同开度的试验性能,通过改变制冷剂的充罐量和膨胀阀开度,将R744/R290混合工质应用于空气源热水器并展开了进一步研究。结果表明:R744/R290混合工质的最优充罐量在525g附近,此时系统的制热性能系数较高;混合工质在最优充罐量下,分别设定开度250P、275P、300P、325P、350P进行试验,结果表明:最佳开度同样为300P,其制热性能系数最大为4.127,较直接灌注该配比混合制冷剂的COP提高13.2%,略低于R290系统(300P)的性能;推荐使用混合工质充罐量为525g、开度为300P的组合应用于空气源热泵热水器。本文为R744/R290空气源热泵热水器的进一步研究提供了有益参考,并且该混合制冷剂在环保性能方面很有优势,具有广阔的市场前景。
[Abstract]:While the ozone hole problem has improved, global warming is getting worse year by year. The European Union and other developed countries have started legislation to limit the use of high global warming potential HFCs refrigerants, zero ODP. The natural working medium of low GWP is reappreciated. R744CO2) belongs to low temperature and high pressure refrigerant, and has the advantage in making hot water by heat pump. But the material strength of the equipment and the sealing requirements of accessories are more stringent; The ODP of R290 (propane) is only 20. Compared with R22, R290 has lower vapor pressure and higher latent heat of vaporization, but flammable and explosive is the biggest safety hazard. Using R290 as the main component and R744 as the addition component, the mixture of R744 / R290 was applied to air source heat pump water heater and studied deeply. R22 refrigerant was tested on the modified test rig. The results showed that the maximum heating performance coefficient of R22 was 4.176 when the tank filling capacity was 1.15kg. Secondly, the direct perfusion substitution test of R290 refrigerant is carried out. The results show that the optimal tank filling capacity of the system is 450 g. The maximum heating performance coefficient is 3.907. Under the optimal tank filling capacity of R290 system, different expansion valve opening is set up. The results show that the pulse opening is 300P. The maximum heating performance coefficient of R290 system is 4.251, which is higher than that of direct perfusion substitution test. It is a little higher than R22 system, and the tank filling capacity is only 39.1% of R22. According to the experimental performance of R290 system with different opening degree, by changing the filling capacity of refrigerant and the opening of expansion valve. The mixture of R744 / R290 and R744 / R290 was applied to the air source water heater and the results showed that the optimal filling capacity of the mixture of R744 / R290 was about 525g. The heating performance coefficient of the system is high. Under the optimal tank filling quantity, the opening degree of the mixed working fluid was set at 250Pn275Pn325Pn350P respectively. The results showed that the optimum opening degree was also 300P. The maximum heating performance coefficient is 4.127, which is 13.2% higher than that of COP directly infused with the mixed refrigerant, and is slightly lower than that of R290 system (300P). It is recommended that the tank filled with mixed working fluid should be 525g. The combination of the opening of 300P is applied to air source heat pump water heater. This paper provides a useful reference for the further study of R744 / R290 air source heat pump water heater. The mixed refrigerant has advantages in environmental protection and has a broad market prospect.
【学位授予单位】：中原工学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU822

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