土壤源热泵适用性分析

分析了土壤源热泵的初投资和地埋管占地面积问题,以及机组运行后土壤温度和系统COP变化等情况,然后与传统闭式冷却塔对比做了运行费用分析,最后提出了土壤源热泵的适用范围。     

土壤排取热量不均衡地区地源热泵系统应用研究

对于土壤排取热量不均衡地区,地源热泵应用过程中常会出现土壤热失衡问题,该问题严重制衡了地源热泵系统在该地区长期高效稳定运行。针对此类地区土壤排取热量严重失衡的特点,同时基于土壤排取热量平衡的理念,提出太阳能对土壤进行全年补热的地源热泵—太阳能耦合系统,并通过一个典型工程案例对地源热泵—太阳能耦合系统的设计思路、技术方案、运行策略、经济性能等方面进行了分析与研究。结果表明,相比于常规能源系统,本项目地源热泵—太阳能耦合系统每年可节能308万kWh,节约运行费用47.64万元,节能率达72.13%,节能减排及环境、社会效益非常显著,以期为土壤排取热量不均衡地区地源热泵系统的相关研究及其工程应用提供参考。     

热泵系统的经济性分析

对空气源热泵、地源热泵、太阳能辅助的地源热泵系统进行了经济性分析,以空气源热泵系统为对象,定量计算并比较了地源热泵和太阳能辅助地源热泵的节能效果,验证了这两者在经济上的优越性,并指出了节能与降低成本的环节与措施.     

消防水池在地源热泵系统运行特性的数值分析

通过CFD技术模拟计算了消防水池在地源热泵工程应用中的温度变化情况,发现消防水池与地源热泵联合运行是可行的;水池中水体温度有明显的分层现象。     

基于系统能效的复合式地源热泵群控系统探讨

提出了一种基于系统能效的复合式地源热泵群控系统,可以根据地源热泵运行参数的变化判断系统运行状况,提供几种合理的调节策略,预计算每种调节策略执行后系统运行状况的变化趋势和系统的整体能效比,选择能效比最高的调节策略对复合式地源热泵系统进行调节。     

Study on the relationship between the shallow ground temperature of embankment and solar radiation in permafrost regions on Qinghai–Tibet Plateau

The temperature field of permafrost embankments is a key factor to determine the embankment stability. On the basis of observed climate data and field-temperature values in Beiluhe on the Qinghai–Tibet Plateau, this paper uses statistics methods to set up a regression equation between the temperature at shallow ground depth (0.5 m) and the net radiation on embankment horizontal surface. There is a good linear relation between the temperature and the net radiation after the phase difference is removed. Moreover, an empirical formula consisting of the shallow-ground temperature of (0.5 m) and the direct solar radiation is proposed. It is also suitable for the area having high elevation at the Beiluhe site. These formulas combining with the law of documents and materials suggest that there exists an obvious linear relation between the temperature on horizontal surface and the direct solar radiation. However, there is hardly linear relation between the temperature and the direct solar radiation on embankment slopes. The key factor is that the railway embankment slope has a relatively heavier gradient. The slopes with heavier gradient have different heat transfer characteristic during a specific year. In summer, the sun is shining straight on the ground, which results in a relatively lower direct solar radiation on slopes; however, because of diffuse radiation and higher temperatures of the horizontal surface, temperatures on slopes are relatively higher. In winter, the direct solar radiation on shady slopes is even zero, meaning that there is almost no direct solar radiation. Thus, the relations between the temperature and the direct solar radiation on slopes are more complicated.     

太阳能-地源热泵复合系统的实验研究

地源热泵是利用可再生能源地热能的一种高效热泵系统,是未来发展的趋势。但在我国北方地区,大部分以热负荷为主,冬季地下埋管的取热量高于夏季的释热量,长期运行会破坏土壤温度场。介绍了太阳能-地源热泵复合系统,通过实验验证了太阳能辅助系统能够有效恢复土壤温度,提高系统性能系数,可以实现热泵长期稳定的运行。     

基于CFD技术的预冷参数对盒装荔枝微环境温湿度的影响

目的 深入研究外环境参数对荔枝包装盒内环境的影响，获得荔枝包装盒内外环境温度湿度规律。方法 建立盒装荔枝果实和外流场的三维模型。结合荔枝果实和包装物理特性，对预冷过程中包装荔枝果实内外环境温湿度变化进行数值分析，获得包装内流场的分布情况。结果 在达到二分之一冷却时间之前，提高风速可以缩短预冷时间，并且能够加快荔枝果实的传热;在达到二分之一冷却时间之后，风速超过6 m/s后，荔枝果实温度变化不显著，相邻风速间果实温度标准差的差值较小，标准差趋于稳定;包装内相对湿度主要受荔枝果实温度的影响;预冷初始阶段选择较低环境温度，有利于加快荔枝果实与空气的传热，促进果实温度的降低，但是荔枝果实间的温度差异随着环境温度降低而增大。结论 在预冷期间，外环境参数温度和风速对包装内环境温湿度有较大的影响。     

地源热泵在广东地区空调工程中应用可行性分析

分析计算了广州市自然气候环境、土壤状况和介质温度,对多种形式的地源热泵空调系统在广东地区应用的条件和可行性进行了分析,提出单一地源热泵空调技术并不适合广东地区使用,广东地区应因地制宜开展地源热泵空调组合技术研究.     

Experimental investigation of a reversible heat pump/organic Rankine cycle unit designed to be coupled with a passive house to get a Net Zero Energy Building

This paper presents an innovative reversible Heat Pump/Organic Rankine Cycle (HP/ORC) experimental unit designed to be coupled to a Net Zero Energy Building (connected to a 120 m² thermal solar roof and a ground heat exchanger). The system can operate in three different modes: an ORC mode to produce electricity when a large amount of heat is collected by the solar roof, a direct heating mode using exclusively the solar roof, and a HP mode for space heating during cold weather conditions. This paper describes a comprehensive experimental campaign carried out on a prototype unit using a modified HVAC scroll compressor (4 kWe). From the results, the technical feasibility of the system is demonstrated. A cycle efficiency of 4.2% is achieved in ORC mode (with condensation and evaporation temperature respectively of 25 °C and 88 °C) and a COP of 3.1 is obtained in HP mode (with condensation and evaporation temperature respectively of 61 °C and 21 °C).     

基于垂直U型埋管换热器的圆柱源理论及其应用研究

基于经典常热流圆柱源理论，引入叠加原理与负荷累积思想将其发展为能够适用于长时期短时间步长变热流地源热泵系统模拟的变热流圆柱源模型，并引用实例从理论与实验两方面对改进模型的有效性进行了验证。将圆柱源理论模型应用于太阳能-土壤源热泵系统联合供暖运行性能的数值模拟，结果表明：对于青岛地区，太阳能-土壤源热泵联合供暖运行模式相比地源热泵单独运行节能8．3％。14．5％，就各运行模式而言，带有蓄热水箱的联合运行模式二效果最佳；通过优化进一步得出：其设计可按能量比例63％与37％或尺寸比例13．8m（埋管）/m^2（集热器）来分别确定盘管长度与集热器面积的大小；至于系统经济性，只有当单位面积集热器价格小于5．81m埋管所需费用时，SESHPS在经济上才是可行的。     

应急避难场所蓄冰柜降温除湿特性研究

为了得到应急避难场所蓄冰柜降温除湿特性以及环境温湿度和进风速度对蓄冰柜传热传质的影响,基于CFD软件FLUENT,建立了蓄冰柜降温除湿模型,通过在其中添加自定义能量源项和质量源项的方法进行数值模拟。结果表明：出风温湿度随进风温湿度的增大而增大,热质传递之间的相互影响较小,出风温湿度随进风速度的增大而增大,但单位质量湿空气的热质传递效率下降,降温除湿量与进风速度近似于成正比关系,研究结果可为蓄冰柜在应急避难场所的应用提供参考。     

地埋管热泵在湘东地区某图书馆应用的可行性分析

地埋管热泵系统具有可再生、节能、环保及寿命周期长的巨大优势,但也同时具有占地面积大、初投资高及适用自然条件相对较为苛刻等劣势。通过对地埋管热泵在湘东地区某图书馆的应用进行可行性分析,阐述了工程建设前进行可行性分析的必要性,并从场地情况、岩土体热物性测试结果、节能效果、经济效益及环保效益五个方面分析了该工程应用地埋管热泵的可行性。在此基础上对地埋管热泵在湘东地区的推广前景进行了简要分析,从而为本地区的类似工程提供参考。     

Modelling a ground-coupled heat pump system using adaptive neuro-fuzzy inference systems

The aim of this study is to demonstrate the usefulness of an adaptive neuro-fuzzy inference system (ANFIS) for the modelling of ground-coupled heat pump (GCHP) system. The GCHP system connected to a test room with 16.24 m² floor area in Fırat University, Elazığ (38.41°N, 39.14°E), Turkey, was designed and constructed. The heating and cooling loads of the test room were 2.5 and 3.1 kW at design conditions, respectively. The system was commissioned in November 2002 and the performance tests have been carried out since then. The average performance coefficients of the system (COPS) for horizontal ground heat exchanger (GHE) in the different trenches, at 1 and 2 m depths, were obtained to be 2.92 and 3.2, respectively. Experimental performances were performed to verify the results from the ANFIS approach. In order to achieve the optimal result, several computer simulations have been carried out with different membership functions and various number of membership functions. The most suitable membership function and number of membership functions are found as Gauss and 2, respectively. For this number level, after the training, it is found that root-mean squared (RMS) value is 0.0047, and absolute fraction of variance (R²) value is 0.9999 and coefficient of variation in percent (cov) value is 0.1363. This paper shows that the values predicted with the ANFIS, especially with the hybrid learning algorithm, can be used to predict the performance of the GCHP system quite accurately.     

露点蒸发冷却装置性能评价指标的研究

本文通过搭建逆流式露点蒸发冷却装置,实验研究了空气入口温度、湿度和风速对露点效率、湿球效率、?效比等各性能评价指标的影响,提出了能够反映湿通道潜热交换的强弱和装置性能的适用于露点蒸发冷却的评价指标——换热放大系数.研究结果表明:进口温度为33、相对湿度为22％时,当风速从1 m/s增至3 m/s,制冷量从29.5 kW...     

可再生能源在空调制冷中的应用

针对目前压缩式制冷技术带来的能源短缺和环境污染问题，介绍了几种可再生能源在空调制冷中的应用技术，如地道风供冷、地源热泵系统、太阳能空调制冷，分析了可再生能源用于空调制冷的特点及发展现状，并对其应用前景做了展望。     

Exergy and energy analysis of a ground-source heat pump for domestic water heating under simulated occupancy conditions

This paper presents analysis of a 5.275 kW (1.5-ton) water-to-water ground source heat pump (WW-GSHP) satisfying hot water needs in a 345 m² research house operated under simulated occupancy conditions. The hot water use protocol from the Building America Research Benchmark Definition claims to capture the living habits of the average American household and its impact on energy consumption.     

土壤源热泵在天津某别墅项目的应用及其经济分析

针对土壤源热泵空调系统的特点,以天津地区某别墅项目为例,从工程概况、系统布置、机组选择、钻孔数量的确定以及埋管沉沙的处理措施等方面介绍了土壤源热泵的实际应用情况.同时,比较了土壤源热泵、空气源热泵与多联机的初投资和运行费用情况,可为土壤源热泵在天津地区的应用提供参考.     

A minichannel aluminium tube heat exchanger – Part III: Condenser performance with propane

This paper reports heat transfer results obtained during condensation of refrigerant propane inside a minichannel aluminium heat exchanger vertically mounted in an experimental setup simulating a water-to-water heat pump. The condenser was constructed of multiport minichannel aluminium tubes assembled as a shell-and-tube heat exchanger. Propane vapour entered the condenser tubes via the top end and exited sub-cooled from the bottom. Coolant water flowed upward on the shell-side. The heat transfer areas of the tube-side and the shell-side of the condenser were 0.941 m² and 0.985 m², respectively. The heat transfer rate between the two fluids was controlled by varying the evaporation temperature while the condensation temperature was fixed. The applied heat transfer rate was within 3900–9500 W for all tests. Experiments were performed at constant condensing temperatures of 30 °C, 40 °C and 50 °C, respectively. The cooling water flow rate was maintained at 11.90 l min⁻¹ for all tests. De-superheating length, two-phase length, sub-cooling length, local heat transfer coefficients and average heat transfer coefficients of the condenser were calculated. The experimental heat transfer coefficients were compared with predictions from correlations found in the literature. The experimental heat transfer coefficients in the different regions were higher than those predicted by the available correlations.     

复合式地源热泵系统三维非稳态数值模型研究

在冬冷夏热且夏季冷负荷远大于热负荷地区常采用复合式地源热泵系统,其中控制策略存在极大优化空间。当需要获得地下土壤温度分布,或将地下某点参数作为系统运行模式的控制参数时,就需要建立精确可靠的三维非稳态模型。利用FLUENT软件建立带有冷却塔的三维非稳态复合式地源热泵系统数值模型,详细介绍热泵机组,土壤换热器,冷却塔,板式换热器等主要部件的建模过程,对系统设计及运行控制策略研究提供极大帮助。