The electric-driven heat pump technology is commonly applied for space heating and cooling for buildings,and also becomes the key link for cooperation with power grid to consume clean electricity.This paper proposes a high-efficiency heating and cooling system by combining the electric-driven heat pump technology with the medium-depth ground heat exchanger for heating in winter and the cooling tower for cooling in summer.Then the user-side energy storage system is applied for daily heat and cool storage.With this system,the design method and control strategy are proposed to fully absorb the local photovoltaic power generation and municipal clean power.Furthermore,this paper conducts a case study on a large public building with quantitative analysis,so as to analyse the actual energy-saving and CO2 emission reduction effect.

推进北方地区清洁供暖是党和政府及社会各界高度关注的重大民生工程,是蓝天保卫战中最艰巨的任务.本项目响应国家清洁供暖和双碳战略重大需求,攻克了低环境温度条件下高热负荷应用的可再生能源供暖难题,开展了中深层地埋管热泵供暖"理论研究-关键产品-设计施工-标准规范"全链条创新工作.首创超长同轴、密闭金属套管结构换热器,专用高蒸发温度、小热源流量的高效变频离心热泵机组和无毒、长时间流态化孔壁封堵压浆材料,构建了勘察与计算互校的系统化设计方法,独创专用施工工艺,主编系列中深层地埋管热泵供暖工程技术标准,形成了规模化应用技术体系,有力推动了我国北方地区可再生能源供暖的实施,为我国建筑供暖应对气候变化提供了全新解决方案.

建立了含湿混合气体横掠水平管束对流冷凝换热模型,对含湿烟气余热回收换热器的换热特性开展了理论研究,分析了结构参数的影响规律.结果表明:随着管排数的增加,换热器平均热流密度呈现先增大后基本不变的趋势,平均换热系数先增大后减小,存在一个最佳管排数使余热回收效率最高;增大管排的横向间距、减小管排纵向间距可以使换热效果提高;当换热管径从30 mm减小到11.25 mm时,换热器平均换热系数增大45.7％,同时换热器的占用空间减小62.5％.

考虑到流动区域的复杂性及投影法求解非定常问题的高效性,本文发展了 一种基于非结构化网格的无压力型投影法,使其能够完成复杂流动区域内非定常流动问题的高效求解.算法实施中,首先基于不包含压力项的预测方程完成中间速度求解,然后根据包含压力项的修正方程完成压力场求解,最后基于压力场对速度场进行修正.基于本文算法,对方腔顶盖驱动流典型算例进行了模拟分析,通过与前人结果对比,验证了本文算法的准确性.

介绍了中深层地埋管供热系统的原理及其特点,分析了该技术的研究进展.以西安市某中深层地埋管供热工程项目为例,进行了运行工况连续测试与监测,分析了热源侧取热量、用户侧供热量、热泵机组效率、系统效率等关键指标,为中深层地埋管供热技术的应用提供参考.

The medium-depth geothermal heat pump systems (MD-GHPs) use vertical concentric deep borehole heat exchangers (DBHEs) with depth more than 2 km to extract heat from medium-depth geothermal energy, which provides a higher-temperature heat source and improve the energy performance of heat pump obviously. This paper introduces the field test on energy performance of heat pumps in MD-GHPs. Results show that the outlet and inlet water temperature of DBHEs reach 33.0 degrees C and 23.7 degrees C respectively, thus the COP of heat pumps reaches 5.70. However, the heat pump with constant speed compressor is identified unsuitable for operation with high-temperature heat source. Besides, the high water resistance, low water temperature difference and energy efficiency lead to the poor energy performance of water pumps. Thus the high-temperature heat source hasn't been fully utilized. Then based on analysis of field test results, the design parameters of heat pump are optimized and the variable speed centrifugal compressor is applied. While the design parameters and control strategy of water pumps are optimized. Finally, the optimization effect is examined through practical application and the SPFH1, WTFu, WTFg, SPFH3, and SPFH4 of MD-GHPs reach 7.71, 57.2, 97.6, 7.15 and 6.35 separately, which are obviously improved. (C) 2019 Elsevier B.V. All rights reserved.

Presents the system composition,basic information of projects and monitoring points layout.Based on more than forty-eight hours' continual monitoring,obtains the actual operational condition of the medium-depth geothermal heat pump systems.Presents the continual monitoring results of outlet water temperature in the heat source side of several common heat pump systems.The comparison shows that outlet water temperature of heat source of the medium-depth geothermal heat pump systems is obviously higher than other conventional heat pump systems.The calculation result shows that heat charge rate per unit length of heat exchanger in heat source side of medium-depth geothermal heat pump system reaches 2.0 to 3.6 times of that of conventional ground-source heat pump system,and that the energy efficiency ratios of units and system are both improved,and that the medium-depth geothermal heat pump system is suitable for space heating of residential buildings.