基于太阳能热补偿的连栋温室高效地源热泵系统设计与试验

Design and Experiment of High-efficiency Ground Source Heat Pump System for Multi-span Greenhouses Based on Solar Thermal Compensation

摘要:

为解决北方连栋温室冬季供暖能耗高、调控精度低，夏季降温效果差、耗水量大，且长期运行易引发土壤热失衡问题，本研究设计了一套基于太阳能热补偿的连栋温室高效地源热泵集成系统（简称高效地源热泵系统）。通过多维度协同优化，实现地埋管换热、变频热泵机组、"顶置辐射板+侧墙对流散热器"复合散热末端与太阳能热补偿的全链条高效匹配，采用复合散热模式适配温室空间特性，构建太阳能热补偿机制。以北京通州11 000 m2的Venlo型连栋温室为研究对象开展全年试验，结果显示：冬季室外平均温度-5℃时，系统平均制热能效比（COP）达5.7，室内日间适宜作物生长温度18~25℃、夜间时段稳定不低于16℃，波动不大于±1.5℃；夏季室外平均32℃时，系统平均制冷能效比（EER）达7.0，室内温度低于26.7℃，相对湿度维持65%~75%。相较于传统"燃煤+风机湿帘"模式，系统综合节能率达54.2%，单位面积运行成本降至10.8元/（m2·季）；太阳能热补偿对土壤热平衡的调控作用，使土壤年温度变化4.4~5.9℃，热失衡系数降至8.7%，有效抑制深层土壤冷累积，且稳定的温湿度环境使番茄单株产量提升19.4%。研究结果为北京及华北同类气候区连栋温室绿色低碳节能调控提供了技术可行、经济合理的解决方案。

Abstract:

Aiming to address the issues of high heating energy consumption and low control accuracy in winter, poor cooling performance and high water consumption in summer, as well as the long-term risk of soil thermal imbalance in northern multi-span greenhouses, an efficient ground-source heat pump integrated system with solar thermal compensation (referred to as the efficient GSHP system) was designed. Through multi-dimensional collaborative optimization, the system achieved full-chain efficient matching among borehole heat exchangers, variable-frequency heat pump units, a combined terminal system consisting of overhead radiant panels and sidewall convector radiators, and solar thermal compensation. The combined terminal configuration adapted to the spatial characteristics of the multi-span greenhouse, while a solar thermal compensation mechanism was established. A year-round experiment was conducted in a Venlo-type multi-span greenhouse with an area of 11,000 m2 in Tongzhou, Beijing. Results showed that at an average outdoor temperature of -5℃ in winter, the system achieved an average coefficient of performance (COP) of 5.7 for heating, maintaining a daytime indoor temperature of 18~25℃ and the temperature during nighttime hours shall not be lower than 16℃ with fluctuations within ±1.5℃. In summer, at an average outdoor temperature of 32℃, the system achieved an average energy efficiency ratio (EER) of 7.0 for cooling, with indoor temperature below 26.7℃ and relative humidity maintained between 65% and 75%. Compared with the conventional "coal boiler + fan-pad" system, the integrated system achieved an overall energy saving rate of 54.2%, and the operating cost per unit area was reduced to 10.8 RMB/(m2·season). The regulating effect of solar thermal compensation on soil thermal balance resulted in an annual soil temperature variation of 4.4~5.9℃ and reduced the thermal imbalance coefficient to 8.7%, effectively suppressing deep soil cold accumulation. Moreover, the stable temperature and humidity environment increased the tomato yield per plant by 19.4%. This system can provide a technically feasible and economically viable solution for green, low-carbon, and energy-efficient climate control in multi-span greenhouses in Beijing and other regions with similar climatic conditions in North China.