拉萨地区空气源热泵供暖应用研究

发布时间：2018-04-05 08:58

本文选题：空气源热泵　切入点：拉萨供暖　出处：《重庆大学》2014年硕士论文

【摘要】：随着西部大开发战略的推进，以拉萨为代表的西部高原城镇的冬季建筑供暖问题受到社会各界的高度重视和支持，政府在“十二五”期间大力开展供暖建设。拉萨属于高原寒冷地区，空气干燥、太阳辐射量大、生态环境脆弱、矿物能源匮乏，这些气候、资源及环境特点要求拉萨地区的建筑供暖模式不可照搬内地经验，需要找到适宜的方案。空气源热泵供暖高效节能、安全环保、设备简单，且由于拉萨冬季空气湿度低不易受到结霜的影响，，当地大量供暖项目采用了空气源热泵作为热源。然而，高原大气压低、空气密度小等因素对空气源热泵的运行产生了不利的影响。因此，本文开展了空气源热泵在以拉萨为代表的高原寒冷地区的供暖应用研究。本文首先根据拉萨地区的气象条件和地理特点计算了当地的空气物性参数，结合空气源热泵冷热水机组蒸发器的结构特征，分析了高原环境对蒸发器换热性能的影响。接着介绍了结霜的途径和判定策略，通过理论分析总结出空气源热泵在拉萨低湿环境下供暖运行不易结霜。建立了空气源热泵冷热水机组及各部件的数学模型，对算法流程进行了阐述，利用MATLAB软件分别对空气源热泵模型在拉萨和平原地区的性能进行了编程及模拟计算，并对结果进行了对比分析。结果表明，在不考虑结霜影响的情况下，拉萨地区热泵制热量、性能系数分别下降了16.2%～19.8%、9.5%～12.5%。然后对拉萨地区某空气源热泵供暖工程进行了实验测试，分析了室外空气温度、出水温度对热泵制热量、性能系数的影响，并将实测值与热泵模型模拟计算值进行对比，验证了模型的准确性和可行性。根据热泵模型提出了拉萨地区空气源热泵实际制热量高原修正系数为0.80～0.84，并将实际制热量与位于空气源热泵结霜区的平原城市作比较，表明空气源热泵在拉萨地区制热量大于部分低温高湿的内陆平原城市。利用DeST模拟软件计算了拉萨地区某建筑供暖期的逐时热负荷，并对热负荷变化规律进行了分析。采用负荷频率法对几种以空气源热泵为主的复合式供暖系统的能耗进行了对比研究，并对其节能性和环保性进行了分析。结果表明，空气源热泵+太阳能供暖系统在拉萨地区供暖季运行能耗最低、环保效益最佳，适宜在拉萨供暖工程中推广应用。
[Abstract]:With the promotion of the strategy of western development, the heating problem of the western plateau towns, represented by Lhasa, is highly valued and supported by all walks of life. The government vigorously carried out heating construction during the 12th Five-Year Plan period.Lhasa is a cold plateau region with dry air, large solar radiation, fragile ecological environment, and lack of mineral energy. These climatic, resource and environmental characteristics require that the building heating model in Lhasa should not copy the experience of the interior.A suitable solution needs to be found.Air source heat pump heating is energy efficient, safe and environmental protection, simple equipment, and because the low air humidity in Lhasa winter is not easy to be affected by frost, a large number of heating projects in the local air source heat pump as a heat source.However, low atmospheric pressure and low air density have a negative effect on the operation of air source heat pump.Therefore, the application of air source heat pump in the cold plateau region represented by Lhasa is studied in this paper.Based on the meteorological conditions and geographical characteristics of Lhasa region, the physical parameters of local air are calculated, and the influence of plateau environment on the heat transfer performance of evaporator is analyzed according to the structural characteristics of evaporator of air-source heat pump unit.Then it introduces the way of frosting and the judging strategy, and concludes that the air source heat pump is not easy to frost in the low humidity environment of Lhasa by theoretical analysis.The mathematical models of air-source heat pump units and their components are established, and the algorithm flow is described. The performances of air-source heat pump models in Lhasa and plain areas are programmed and simulated by MATLAB software.The results are compared and analyzed.The results show that the heat capacity of heat pump in Lhasa area is decreased by 16.219.89.5and 12.5g, respectively, without taking into account the effect of frosting.Then an experimental test of an air-source heat pump heating project in Lhasa area was carried out, and the effects of outdoor air temperature and outlet temperature on heat pump heating capacity and performance coefficient were analyzed, and the measured values were compared with the simulated results of heat pump model.The accuracy and feasibility of the model are verified.Based on the heat pump model, the plateau correction coefficient of the actual heating capacity of air-source heat pump in Lhasa is put forward to be 0.800.84, and the actual heating capacity is compared with that of the plain city in the frost-forming area of air-source heat pump.The results show that the heating capacity of air source heat pump in Lhasa is higher than that in some inland plain cities with low temperature and high humidity.The hourly heat load of a building in Lhasa area during heating period was calculated by using DeST software, and the variation law of heat load was analyzed.The energy consumption of several hybrid heating systems with air source heat pump is studied by using load frequency method, and its energy saving and environmental protection are analyzed.The results show that the air source heat pump solar heating system has the lowest energy consumption and the best environmental benefit in the heating season in Lhasa, which is suitable for popularization and application in Lhasa heating engineering.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU83

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