带闪发器的R32空气源热泵系统性能研究
发布时间:2018-04-08 19:12
本文选题:空气源热泵 切入点:闪发器 出处:《天津商业大学》2017年硕士论文
【摘要】:日益严重的能源紧缺及环境污染问题,亟待解决的臭氧层保护及温室气体减排问题已成为国际社会共同面临的难题。近年来,R32以其零ODP、低GWP、优良热物性及低廉价格逐渐显露出竞争优势。为解决寒冷地区冬季采暖用空气源热泵出现的制热量不足、排气温度高、系统工作不稳定等问题,本课题利用闪发器中间补气增焓技术,对传统涡旋压缩机单级热泵系统进行改进,在提高系统制热量,满足供暖需求的同时,降低压缩机排气温度,对系统运行的稳定性及安全性的提高具有重要意义。本文对提高空气源热泵系统性能的方法进行了比较分析,着重分析了闪发器中间补气技术的特点及需满足的必要条件,建立了中间补气涡旋压缩机数学模型,利用EES软件编程并理论计算分析了不同环境条件下补气压力的最佳取值范围,并将最佳补气压力下闪发器中间补气热泵系统性能参数与传统热泵系统进行对比,得出两系统参数变化规律及其最佳切换环境温度范围。基于理论计算结果,对闪发器中间补气空气源热泵系统实验台主要设备进行校核计算选型,在焓差法实验室搭建热泵系统性能测试实验台,按国家标准规定制定实验工况,测试不同补气压力下闪发器热泵系统动态性能,实验研究了闪发器中间补气R32空气源热泵系统的变工况性能。实验结果表明,在保持室内侧环境干球温度20°C不变、室外侧环境干球温度不同的条件下,闪发器热泵系统的相对补气量、制热量以及压缩机耗功均随着相对补气压力的增高而增大,排气温度随着相对补气压力的升高而下降。制热COP则随着相对补气压力的升高呈现出不同的变化趋势:在环境温度高于-5°C时,相对补气压力升高,制热COP呈缓慢下降趋势;在环境温度低于-5°C时,相对补气压力升高,制热COP则出现先增加后减小趋势。综合考虑各因素,在保证系统运行可靠前提下确定最佳相对补气压力为1.2左右。通过对最佳相对补气压力下闪发器热泵系统与传统单级系统性能实验数据的对比分析,结果表明闪发器中间补气系统比传统热泵系统在低温工况下具有更大的制热量以及更低的排气温度;在室外干球温度为-10°C时,闪发器中间补气热泵系统制热量较传统单级系统提高了14.6%,排气温度降低了19.2°C。在环境温度高于-3.1°C时,传统单级系统制热COP高于闪发器补气系统,在环境温度低于-3.1°C时,闪发器补气系统制热COP高于传统单级系统,因此确定闪发器系统与传统单级系统切换的室外环境温度范围为-3.1°C左右。最佳相对补气压力下闪发器补气系统与过冷器中间补气系统性能参数的对比分析表明,闪发器中间补气系统具有更高的制热COP,在室外干球温度为-10°C的条件下,闪发器系统制热COP提高了4.9%。总的来说,闪发器中间补气可以有效改善空气源热泵冬季运行性能,使系统安全可靠,同时具有结构简单等特点,适合冬季寒冷地区采暖使用。
[Abstract]:The shortage of energy and the increasingly serious problem of environmental pollution, ozone layer protection and greenhouse gas emission reduction problem has become a problem facing the international community. In recent years, R32 with zero ODP, low GWP, low price and excellent heat gradually revealed competitive advantage. For the lack of capacity to solve the cold winter heating area of air source heat pump for the exhaust temperature is high, the system is not stable, the subject of the use of flash-tank intermediate pressure enthalpy of scroll compressor technology, traditional single-stage heat pump system was improved, in improving the system of heat, to meet the heating needs at the same time, reducing the exhaust temperature of the compressor, is of great significance to the stability the safety and operation of the system is improved. This paper makes a comparative analysis on the methods of improving the performance of air source heat pump system, analyzes the characteristics of flash-tank middle Qi technology and full The necessary conditions of foot, establishes the mathematical model of scroll compressor air, EES software programming and the analysis of the optimal range of air pressure under different environmental conditions by theoretical calculation, and comparing the flash parameters of heat pump system performance is between Qi and the traditional heat pump system optimal superfeed pressure, the variation of system parameters and the best two switching environment temperature range. Based on the theoretical calculations, to check the flash-tank intermediate pressure air source heat pump experimental system of main equipment selection calculation, difference method in laboratory experiment system built enthalpy heat pump system performance test, establish experimental conditions according to the national standards, testing different air pressure economizer heat pump system dynamic performance. Experimental study on the performance of variable working condition flash-tank middle air R32 air source heat pump system. The experimental results show that the indoor environment to keep dry side The temperature of 20 DEG C ball bulb temperature conditions unchanged, different outdoor environment dry, flash relative air supply heat pump system, heat and power consumption of the compressor increases with the increase of relative air pressure, exhaust temperature decreases with the relative air pressure. The heating of COP would increase with the relative air pressure showing a different trend: the ambient temperature is higher than -5 ~ C, the relative air pressure, heating COP decreased slowly; when the ambient temperature is lower than -5 ~ C, the relative air pressure, heating COP first increases and then decreases. The trend of comprehensive consideration of various factors, in the system reliable premise to determine the optimal relative intermediate pressure is about 1.2. By comparing the optimal relative air under pressure economizer heat pump system and the traditional single level system performance analysis of experimental data, results show that flash-tank intermediate pressure system The greater than with traditional heat pump system in low temperature condition of heat capacity and lower exhaust temperature; in the outdoor dry bulb temperature is -10 DEG C, flash-tank middle air heating heat pump system compared with the traditional single level system is increased by 14.6%, reducing the exhaust temperature of 19.2 DEG C. at ambient temperature is higher than -3.1. C, heating COP traditional single level system is higher than that of economizer of air supply system, when the ambient temperature is lower than -3.1 DEG C, flash heat supply system is COP higher than the traditional single level system, thus determining the outdoor temperature range of the switching flash-tank system and the traditional single level system for -3.1 degrees C best. The relative air under pressure economizer air system and compared the parameters of system performance analysis shows that the intermediate cooler air, economizer air heating system with intermediate COP higher, dry bulb temperature conditions is -10 DEG C in the outdoor, the flash heater system of COP increased by 4. 9%., in general, the middle air makeup of flash blink can effectively improve the performance of air source heat pump in winter, make the system safe and reliable, and has the characteristics of simple structure, which is suitable for heating in cold regions in winter.
【学位授予单位】:天津商业大学
【学位级别】:硕士
【学位授予年份】:2017
【分类号】:TU83
【参考文献】
相关期刊论文 前10条
1 王超;陶乐仁;杨丽辉;虞中e,
本文编号:1722974
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