【作者】 徐永军；

【导师】 卢军；

【作者基本信息】 重庆大学 ， 供热、供燃气、通风及空调工程， 2011， 硕士

【摘要】 随着我国城市化进程的加快,经济的快速发展和人们生活水平的提高,公共建筑和住宅的供热和空调已经成为普遍的需求。空调系统能耗问题日益突出,城市建筑的快速发展给地源热泵系统这种节能空调新技术的使用带来了巨大的发展潜力。在建筑的空调冷负荷比热负荷大得多的地区,采用地源热泵空调系统,地埋管排入土壤中的热量和从土壤中提取的热量不平衡,长期作用会使土壤温度升高,热泵夏季进水温度升高从而降低系统性能,增加了系统的能耗。因此可在冷负荷占优势建筑中采用辅助冷却的复合式地源热泵系统,根据建筑热负荷设计地埋管换热器,减少地下换热器的长度,降低了系统的初投资,并通过辅助冷却设备来消除土壤中的不平衡热量,改善了系统性能。本文首先建立了地源热泵系统以及各个部件的传热数学模型,并对系统模拟计算步骤进行了阐述,分析系统各个部分内在的耦合关系。采用实测数据与模拟计算结果进行比较,验证了传热模型的正确性以及可行性。基于重庆地区某复合式地源热泵示范工程,采用传统型地源热泵系统和传统冷机联合地源热泵的复合式系统分别进行研究。根据DeST能耗模拟软件计算出的全年逐时空调冷热负荷和建立的数学模型,采用不同的控制策略,对传统型和复合式地源热泵系统进行了7年的模拟计算,研究了地源热泵系统初始运行时间点对系统能耗、地埋管换热器钻孔壁温度和进出口水温的影响。对冷负荷占优的建筑采用传统地源热泵系统进行研究,说明了采用复合式地源热泵对节省系统初投资和维持地下土壤热平衡的重要性。为传统冷机联合地源热泵的复合式系统制定了两种控制策略,并与不采用控制策略的运行方式相比,说明在这种复合式地源热泵系统中采用一定的控制手段,维持地下土壤的温度和系统节能性,仍然是很有必要的。在不同控制策略设定值下,分析了复合式系统的运行能耗以及钻孔壁温度两个重要参数,通过对不同控制策略设定值和运行方式下的模拟计算结果进行比较,得出了最佳的控制策略设定值,为实际工程应用提供了运行控制方法和指导。更多还原

【Abstract】 Along with the acceleration of urbanization in our country, the requirement of heating ventilation and air condition (HVAC) of public and residential buildings has become popular demand with the increasing development of economy and the improvement of people’s living standard. However, the traditional heating and cooling system is insufficient for reducing energy consumption. Therefore, renewable technology such as Ground Source Heat Pump (GSHP) with imponderable potential accelerate the building energy saving. While GSHP system is applied in building that is cooling-dominated, especially located in hot-climate areas. The annual accumulated air-conditioning system cooling load is much greater than heating load. Ground temperature will be changed due to imbalance heating and cooling load after long-term circulation. On the other hand, ground heat exchangers operating energy consumption increase as well as system performance reduction will be effected as a result. Towards this background, composite ground source heat pump system with auxiliary cooling function can play an important role in improving existing HVAC system efficiency and reducing the initial cost of the system considerably.In this paper, heat transfer mathematical model has been established to identify the relationship inside heat pump model. Secondly, in order to evaluate the accuracy and feasibility, this analytic model has been validated by field measurement data.Based on a composite ground source heat pump demonstration project in the city of Chongqing, traditional GSHP system and Composite ground source heat pump system are adopted for contrastive research. The entire year cooling and heating load is calculated via DeST (Designer’s Simulation Toolkit) software. Compare traditional GSHP system with Composite GSHP system, analog computation is conducted for 7 years simulative time, analyzing the impact of initial operating time on system performance, ground heat exchangers and water temperature. The initial investment and maintain cost saving by using Composite GSHP system is effective, especially in cooling load dominant area. Two kinds of control strategies are implementing in Composite GSHP system, the result indicate that underground soil temperature has been well maintained and the system energy-saving goal has been achieved. Under different control set point value, this paper analyzes two important parameters, system performance and drilling wall temperature, of the composite system. The best set point value of control strategy was proposed as the result of comparison, and gave rise to operational control method and guidance for practical engineering application.更多还原