用于寒冷地区双级压缩变频空气源热泵的研究

将双级压缩和变频技术有机结合，提出一种适用于寒冷地区双级压缩变频空气源热泵系统。本文得出了该系统最佳中间压力表达式，提出采用效率优先和制热量优先的双控制模式，并根据需要利用变频手段来提高热泵系统的制热性能系数和制热量。试验和模拟计算表明：在冷凝温度50℃和蒸发温度-25℃工况下，系统制热性能系数高于2，压缩机排气温度低于120℃，制热量可以满足用户要求；且试验验证系统运行稳定可靠，可以在-18℃以上的室外低温环境中满足寒冷地区冬季供暖需要。     

一种建筑节能技术——水源热泵空调系统

水源热泵是一种高效节能、经济环保、安全稳定、冷暖两用、运行灵活的新型中央空调系统,它利用地表水(江、河、湖水)、地下水、工业废水及生活废水,又可用取之不尽的海水等,借助热泵系统,既能制冷、又能制热,是一种高效建筑节能技术。     

某宾馆水源热泵系统中变频技术的应用

某宾馆工程地下水源热泵空调系统中,热泵机组在实际运行中不总处于满负荷运行状态。通过采用变频技术和改变深井泵的供水流量,既满足热泵机组所需的水量、节省了水资源,又降低了电费及水费等运行费用。整个冬季供暖期深井泵采用变频技术后,共节省供水量419271m3,共节省耗电量104110kWh,全年共产生经济效益15.48万元。     

转轮热泵耦合式空调系统的节能性研究

主要研究除湿转轮与中高温热泵耦合的空调系统,利用热泵完全满足再生温度和负荷要求,对不同工况下,新风量为20%和10%两种情况的系统性能进行仿真模拟,并与常规再热空调系统进行性能比较,给出节能性分析.随室外空气干球和湿球温度升高,耦合系统的能耗均增加,性能系数(COP)均减小,节能率分别升高和降低,为使冷凝器出口风温满足再生要求的冷凝风量相应增加和减少;随室内空气干球温度升高,能耗增加,COP减小,为满足再生要求需要减少冷凝风量,与相同工况下的常规系统相比,节能率升高,与室内温度为23℃的常规系统相比,节能率降低;随室内空气湿球温度升高,能耗减少,COP增大,节能率降低,为满足再生要求需要增加冷凝风量.新风量为10%的耦合系统与20%时相比,热泵子系统的压缩比减小,COP提高,系统额外节能4%以上,同时两种耦合空调系统,在所研究的温湿度范围内,冷凝风量均远远多于需求的再生风量值.     

杨凌某小区地下水源热泵空调系统冬夏季能效状况实测与分析

以杨凌某小区地下水源热泵系统为对象,于2010年2月及8月份对系统的各用能设备进行实地监测。结合现行能效标准,提出了水源侧输配系统、用户侧输配系统、热泵主机及热泵系统的能效指标。经测试,水源侧、用户侧输配系统及热泵系统均处于非节能状态,热泵主机处于节能状态。该测试结果对于分析各用能设备能耗、发掘系统节能潜力、提高地下水源热泵系统能效具有指导意义。     

空气源单、双级燃气机热泵的应用及其效益分析

提出一种单、双级空气源燃气机热泵,并从多个角度上同传统的蒸汽压缩式热泵和单级燃气机热泵作了比较。结果表明,这种热泵在一次能源利用率、火用效率和经济性上有较大优势,它的推广使用将扩大热泵的适用范围和使用时间,尤其在三北地区。     

太阳能辅助的双源耦合热泵系统制热特性研究

传统空气源热泵在较低环境温度下存在制热量不足和制热效率偏低问题,该文提出一种太阳能辅助的双源双压缩耦合热泵系统,通过集热器将太阳能转化为低温热水以构建太阳能水源热泵单元,利用2台压缩机和1台冷凝器实现太阳能水源热泵单元和空气源热泵单元并联耦合工作。太阳能水源热泵单元和空气源热泵单元既能各自独立运行又能同时运行以满足用户全天候热负荷需求。基于DeST软件评估一个供热期(120 d)郑州某建筑逐时热负荷特性。在建立热力学数学模型基础上编写程序进行新系统循环特性计算和能耗分析,结果表明:双源耦合热泵系统COP_h较传统空气源热泵明显升高;前者日节能率介于1.01%～14.75%之间,在整个供热期总能耗较后者减少8.72%。双源(空气源蒸发器和水源蒸发器)双压缩机并联流程耦合热泵比双源单压缩机串联流程耦合热泵更具有节能优势。     

水源热泵系统的热力学分析

本文通过对水源热泵系统进行热力学分析，既评价了水源热泵系统的能质利用和损失状况．又明确了系统能量损失的主要环节和程度，从而为进一步分析系统用能改进的技术措施提供指导。通过对一实例的分析，指出压缩机、蒸发器和冷凝器都是需要技术改进和进一步节能的部分。     

严寒地区太阳能-空气源热泵系统供暖实验研究

针对严寒地区所构建的太阳能-空气源热泵系统供暖实验装置,进行热泵独立运行及蓄热水箱-热泵双热源联合运行的供暖特性研究。结果表明:使用空气源热泵单独供暖时,当室外温度低于-12℃时系统COPs达到最低,无法满足室内采暖需求;当室外温度在-12～-7℃之间时,室内采暖需求虽可得到满足,但系统COPs仅为1.10～1.44,节能效果不明显;当室外温度大于-7℃时,室内平均温度可达到20℃以上,系统节能性较好;蓄热水箱的加入会影响运行初期机组的稳定性,但可使室温得到快速提升并提高系统的制热性能,在相同运行条件下,蓄热水箱-热泵混合供暖期间室内平均温度为24.61℃,系统COPs为2.01,较蓄热水箱与空气源热泵交替供暖及单一空气源热泵供暖模式分别提高6.90%、21.08%,供暖效果最佳。     

变温热源地热热泵系统的可用能分析

地热能作为一种新能源已成为许多国家的研究重点，如何提高地热能的利用率是其重要的研究方向，而热泵又是其中一项关键技术。本文针对地热热泵系统的变温热源，从减小可用能损失的角度进行了详尽的理论分析。首先，对该地热热泵系统中的各个主要部件进行了可用能分析，发现和能损失情况均与循环工质的性能有关；其次，在实际工况下比较了纯工质和非共沸混合工质的可用能损失情况；最终提出了几种有可能应用于实际地热热泵工况下的循环工质。     

水环热泵空调系统应用性分析

水环热泵空调系统是小型水／空气热泵机组的一种应用。通过连通建筑物周边区和内区的水循环环路将小型水／空气热泵机组并联在一起，形成一个封闭环路，将建筑物内区制冷产生的冷凝热转移到周边区，作为周边区热泵的低温热源。水环热泵空调系统在对建筑物内区供冷的同时实现对周边区供热，使建筑物空调的内、外区冷热相抵，建筑物内部余热得到充分利用，节约了能源。本文比较了水环热泵系统相对于常规空调系统在系统结构、节省能源等方面的优势和应用中遇到的问题，并结合工程应用实例，分析了水环热泵空调系统的经济性。     

复合地源热泵系统冬季供暖运行实验研究

介绍了地源热泵在冬季运行供暖的实验研究,具体分析了长期连续运行时土壤温度的变化规律,热泵机组系统的COP变化情况,以及太阳能辅助系统与地源热泵系统联合运行时土壤温度的变化规律,热泵机组系统的COP变化情况.试验数据表明了增加太阳能辅助地源热泵系统后,显著地提高了冷凝器出口温度和室内温度,有效地提高了热负荷,增加了供热面积.总结出了本地区地源热泵系统的一般运行规律.     

直流变频空气源热泵热水器的实验研究

针对普通定频空气源热泵热水器不能在宽负荷和宽温度条件下运行等缺陷,提出一种直流变频空气源热泵热水器。通过对样机进行实验,得出了制热量、功率、COP值、吸气温度、排气温度等性能参数随压缩机运行频率的变化规律。结果表明直流变频热泵热水器能在宽负荷、宽温度条件下稳定运行。     

Performance analysis of a photovoltaic heat pump

A novel heat pump system is proposed in that the PV/T collector is coupled with a solar assisted heat pump and works as an evaporator. The cooling effect of the refrigerant allows the PV modules to work at lower temperature and so its photovoltaic efficiency is improved. Mathematical model has been developed to analyze the complex energy conversion processes. Numerical simulation was then performed based on the distributed parameters approach. An experimental rig was also built to verify the real performance of the system as compared to the simulation model prediction. The results indicated that this photovoltaic solar assisted heat pump (PV-SAHP) has better coefficient of performance (COP) and photovoltaic efficiency than the separate units. Under the experimental conditions, the COP of the PV-SAHP reached 8.4 and the average value was around 6.5, whereas the average photovoltaic efficiency was around 13.4%. The experimental results were found in good agreement with the theoretical predictions on the system responses to changing environmental conditions.     

别墅型建筑地源热泵空调系统设计

地源热泵是一种利用土壤所储藏的太阳能资源作为冷热源进行能量转换的供暖制冷空调系统,通过输入少量的高品位能源(如电力、机械功、燃气和液体燃料),实现热量从低温热源向高温热源的转移.以上海某小型别墅为对象,设计了一套家用地源热泵空调系统.首先计算了夏季冷负荷和冬季热负荷,然后根据冷、热负荷选择一套水源热泵机组(MWH080CR型机组)和相应的风机盘管,进行了室内水管环路系统、土壤热交换器和地板采暖的设计选型,最后对系统的能效比进行了计算.结果表明,该空调系统具有节能环保、稳定可靠、舒适耐用等优点.     

A study on the design and analysis of a heat pump heating system using wastewater as a heat source

In this study, the compression heat pump system using wastewater, as a heat source, from hotel with sauna was designed and analyzed. This study was performed to investigate the feasibility of the wastewater use for heat pump as a heat source and to obtain engineering data for system design. This heat pump system uses off-peak electricity that is a cheap energy compared to fossil fuel in Korea. For this, the charging process of heat into the hot water storage tank is achieved only at night time (22:00–08:00). TRNSYS was used for the system simulation with some new components like the heat pump, which we create ourselves.As a result, it was forecasted that the yearly mean COP of heat pump is about 4.8 and heat pump can supply 100% of hot water load except weekend of winter season. The important thing that should be considered for the system design is to decrease the temperature difference between condenser and evaporator working fluids during the heat charging process by the heat pump. This heat pump system using wastewater from sauna, public bath, building, etc. can therefore be effectively applied not only for water heating but also space heating and cooling in regions like as Korea.     

Solar space heating and cooling with bi-heat source heat pump and hot water supply system

This paper describes a specific heat pump system that can solve the problem of low heating capacity at a low ambient temperature—one of the largest problems in the air-source heat pump system.

In order to decrease the collector area required, the heat pump system is operated by the air-source during the daytime, but at night or at a very low ambient temperature it can be operated with hot water which has been produced by the collector in the daytime. The effect of the solar energy on the air-source heat pump system has many advantages in the moderate winter climate of Japan. The hot water supply system includes an auxiliary electric heater.

The experiment has been carried out with a prefabricated test house, which has been constructed in Nara with double glazed windows and high thermal insulation. The results of this experiment are that solar energy enhances the total electric energy savings, increases the heating capacity at low ambient temperature, and eliminates the need for reverse cycle defrosting operation, etc.     

Application of a heat pump system using untreated urban sewage as a heat source

Untreated urban sewage contains large amounts of thermal energy; and its temperature is suitable as a heat source in heat pumps for the heating and cooling of buildings. However, it is not widely used in heat pump systems due to the problem of filth. This paper presents an untreated sewage source heat pump (USSHP) system in which auto-avoiding-clogging equipment is used to continuously capture suspended solids in the sewage. Thus, the block problems caused by filtration and fouling in the heat exchanger tubes can be efficiently resolved in this system. In an actual engineering application, the characteristic parameters of USSHP system are tested under typical operating conditions for heating status. Based on the test results, the performances of the USSHP system are examined. The results indicate that the thermal resistance of the convective heat transfer and fouling on the sewage side in the sewage exchanger is 80% of its total thermal resistance. The COP of the heat pump unit and the COP of the USSHP system are 4.3 and 3.6, respectively.     

Chemical heat pump using heat of reversible catalytic reactions

One of the most important objects of research in the field of energy conservation is development of a high temperature heat pump for the industrial sector. In this framework this paper introduces a new concept of heat pump, which is a hybrid between a compressor and chemical heat pump, where instead of the latent heat of liquids, the proposed system uses the heat of gaseous catalytic reversible reactions (type A → B + C). This paper proposes a simple scheme with a mathematical model for the calculation of the parameters necessary to qualify the behaviour of the Heat Reaction Chemical Heat Pump (HRCHP). The Coefficient of Performance (COP) is calculated as a function of the temperature of the heat source, the temperature to which the pump upgrades the heat and the conversion of the chemical reaction. A more optimized scheme is prospected.     

Sustainable sub-geothermal heat pump heating in Serbia

Considering the necessity of improvement of Serbian energy production structure through higher participation of clean and renewable energy sources, the possibility of utilization of low enthalpy geothermal waters have been investigated. Energy potential of ground waters of modest temperature levels is usully neglected since it can not be used for direct heating purposes. Nevertheless, if the appropriate heat pump system is utilized, as described in the paper, the energy efficient and environmentally friendly heating could be achieved. From the environmental aspect particularly interesting would be the application of sub-geothermal heat pump in already existing high-temperature residential heating systems, as a complete substitution of old, low efficiency, highly polluting central heating of a building or a housing block. Besides environmental benefits of the proposed solution, obtained through shutting down the fossil fuel energy sources, paper investigates energetic efficiency of the model system, and discusses its economic justification. To achieve a full sustainability of the proposed heating system the environmental risks, especially deposition of utilized sub-geothermal water, need to be observed in detail.