冬季工况下闭式热源塔换热性能分析

发布时间：2018-04-14 01:11

本文选题：闭式热源塔 + 冬季工况　；参考：《东华大学》2016年硕士论文

【摘要】：目前,建筑物中常用的空气源热泵无法避免因结霜导致的机组效率下降、蒸发温度低等弊端,所以,具有无霜运行能力的闭式热源塔热泵技术是非常符合空调热泵发展趋势的。然而,我国幅员辽阔,南方地区位于多种气候地带,因此,对不同气候特征下闭式热源塔的换热性能进行研究是非常有必要的。首先,本文对闭式热源塔的运行流程及其热泵系统的技术优势进行了介绍。然后,结合闭式热源塔的换热过程和我国南方冬季气候特征,分别建立了其在干工况、湿工况以及防霜工况下的换热模型,确定了其主要技术参数,并阐述了计算方法。根据所建立的换热数学模型,利用MATLAB编写了闭式热源塔的计算程序。通过国内学者的实验实测数据验证了本文建立的数学模型,三个工况的理论计算结果与实验结果的最大误差为8.9%,表明:本文所建立的闭式热源塔的换热模型准确性较高,可以满足其在冬季工况下针对不同气候典型城市换热能力的模拟分析。然后,根据我国南方地区的热工分区选取了三个典型城市——上海、昆明和福州作为研究对象,统计分析了三个城市的气象参数,并利用MATLAB软件模拟计算了闭式热源塔在三个城市的吸热量。研究结果表明,闭式热源塔的吸热量和能效比随湿球温度增加而增加,闭式热源塔的理论防霜时间占供暖期比例随湿球温度增加而减少。在供暖期,闭式热源塔在福州的稳定性最高,比昆明高26.3%,比上海高39.2%,热源塔的稳定性决定了其持续的吸热能力,因此,闭式热源塔在上海的推广应用中更应考虑如何提高热源塔的稳定性;闭式热源塔在福州的平均吸热量最大,比昆明高4.2%,比上海高10%;在福州的最冷月总吸热量最大,比昆明高10.3%,比上海高29.2%;在福州的平均能效比也最高,比昆明高3.9%,比上海高10.1%;在上海、昆明和福州的理论防霜时间分别是2188小时、1466小时和675小时,分别占各自供暖期的67%、58%和45%。闭式热源塔在不同气候特征城市的适用性区别很大,因此,闭式热源塔热泵技术推广应用中应因地制宜,针对不同气候特征优化结构和运行参数。
[Abstract]:At present, the air source heat pump commonly used in buildings can not avoid the disadvantages of low evaporating temperature and efficiency due to frosting. Therefore, the closed heat source heat pump technology with no frost operation ability is very consistent with the development trend of air conditioning heat pump.However, China has a vast territory and the southern region is located in a variety of climatic zones. Therefore, it is necessary to study the heat transfer performance of closed heat source towers with different climatic characteristics.Firstly, the operation process of closed heat source tower and the technical advantages of heat pump system are introduced in this paper.Then, combined with the heat transfer process of the closed heat source tower and the winter climate characteristics of southern China, the heat transfer models under dry, wet and frost-proof conditions are established, and the main technical parameters are determined, and the calculation method is described.According to the established mathematical model of heat transfer, the calculation program of closed heat source tower is compiled by MATLAB.The mathematical model established in this paper is verified by the experimental data measured by domestic scholars. The maximum error between the theoretical calculation results of the three working conditions and the experimental results is 8.9, which shows that the heat transfer model of the closed heat source tower established in this paper is accurate.It can be used to simulate and analyze the heat transfer capacity of typical cities in different climates under winter conditions.Then, three typical cities, Shanghai, Kunming and Fuzhou, are selected as the research objects according to the thermal zones in southern China, and the meteorological parameters of the three cities are statistically analyzed.The heat absorption of closed heat source tower in three cities was simulated by MATLAB software.The results show that the heat absorption and energy efficiency ratio of the closed heat source tower increase with the increase of the wet bulb temperature, and the theoretical frost prevention time of the closed heat source tower decreases with the increase of the wet bulb temperature.During the heating period, the stability of the closed heat source tower is the highest in Fuzhou, 26.3cm higher than Kunming and 39.2% higher than Shanghai. The stability of the heat source tower determines its sustained heat absorption capacity.In the promotion and application of closed heat source towers in Shanghai, consideration should be given to how to improve the stability of heat source towers; the average heat absorption capacity of closed heat source towers in Fuzhou is the largest, 4.2 times higher than that of Kunming and 10 percent higher than that of Shanghai; and the total heat absorption of the coldest month in Fuzhou is the largest.The theoretical frost prevention time in Shanghai, Kunming and Fuzhou is 2188 hours, 1466 hours and 675 hours, respectively, accounting for 6758% and 4545 hours of their respective heating periods, respectively.The applicability of closed heat source tower in different cities with different climatic characteristics is very different. Therefore, the application of closed heat source heat pump technology should be adapted to local conditions, and the structure and operation parameters should be optimized according to different climatic characteristics.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU83

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