燃气机热泵机组隔声装置降噪研究

噪声问题是燃气机热泵走向商业化的一个难题,本文在分析了声源特点的基础上,结合声学理论与实际经验,建立了隔声罩三维模型与双室抗性消声器模型,使用RAYNOISE软件对加装隔声罩前后的燃气机热泵机组的噪声场进行模拟,并且根据本实验台的实际情况设计了燃气机热泵机组的隔声装置,对采用降噪装置后的实验台进行实验测量,总声压级降到77.8dB(A),通过实验验证了设计的合理性。     

夏季冷热联供模式下的燃气机热泵机组性能分析

本文建立了一套以R134a为制冷剂工质、以天然气为一次能源驱动开启式压缩机做功的燃气机热泵系统,研究了当蒸发器进水温度为12～22℃,室外环境温度为24.2～35.6℃,发动机转速为1 400～2 000 r/min,夏季冷热联供模式时,空气源燃气机热泵(GEHP)机组的性能。结果表明:发动机转速和蒸发器进水温度的变化对系统性能的影响大于室外环境温度变化的影响。随着发动机转速由1 400 r/min增至2 000 r/min,系统COP_1、COP_2、PER_1、PER_2分别减小了15.5%、9.9%、18.8%、13.5%。在工况范围内,机组冷水出水温度可达6.7～19.3℃,热水出水温度可达40.7～61.7℃,考虑余热回收情况下系统PER_2可达1.14～1.45。     

水-水燃气机热泵的余热回收

提出了以优质清洁能源为动力的新型高效节能环保供暖空调设备--水-水燃气机热泵水系统余热回收方案,对水-水燃气机热泵的研发和推广应用具有参考价值.     

低温环境下复叠式燃气机热泵的供热性能研究

为了提高燃气机热泵在低环境温度下的制热性能,本文将燃气机热泵技术与复叠式热泵技术相结合,提出了应用于低环境温度下的复叠式燃气机热泵（CGEHP）系统。使用MATLAB软件,建立了CGEHP数学模型。分析了燃气发动机转速、环境温度和系统进水温度对系统供热性能（总供热量、制热性能系数（COP）以及一次能源利用率（PER））的影响规律。结果表明：当环境温度分别为﹣20、﹣15和﹣10 ℃,以NH3-LiNO3作为吸收式热泵系统工质,发动机转速为1 500 r/min时,PER分别为1.0、1.02、1.04,比常规空气源电热泵系统分别提高了24%、15%、5%。     

双管路燃气热泵（GEHP）系统仿真与实验研究

通过建立双管路燃气热泵(GEHP)系统的数学模型,研究了制热工况下系统的环境特性及部分负荷特性.模拟结果表明,双管路燃气热泵的一次能源利用率(PER)随转速升高而降低,即具有良好的部分负荷特性.对双管路GEHP系统的运行特性进行了实验研究,通过实验结果与计算结果的对比,验证了仿真模型的合理性.     

燃气热泵空调技术在重庆的应用分析

介绍了燃气热泵空调的技术原理以及技术特点,并根据重庆地区的气候特点和城市能源现状,分析了燃气热泵空调技术在重庆地区的应用可行性.最后以重庆某办公楼为例,分析了在重庆地区采用燃气热泵空调的运行经济性,对比分析结果表明：该工程采用冷水机组＋燃气锅炉的冷热源方案时,每平米年运行费用为21.78元;采用燃气热泵的冷热源方案时,每平米年运行费用为11.58元,相比冷水机组＋燃气锅炉的方案,可以节约接近一半的运行费用,经济效益明显.     

热泵除霜特性的实验研究

本文对用热力膨胀阀作为除霜时的节流机构的热泵系统进行了实验研究,包括压力、温度、过热度、制冷量、功率等,最后指出热力膨胀阀更适宜除霜,并与毛细管作了对比,并指出了减小除霜时间的措施。     

燃气发动机与电动机联合驱动热泵供热工况运行策略研究

由燃气发动机和电动机联合驱动的混合动力热泵(HPHP)是提高燃气供热和制冷效率的发展方向之一,但其在系统设计和运行策略上还存在提升空间。本文提出了供热和供冷均由燃气发动机与电动机联合驱动的HPHP,并建立数学模型。通过模型计算,针对设计工况下发动机占最大输出功60%下的HPHP,并与燃气机热泵(GEHP)和电热泵(EHP)进行对比,分析了不同环境温度下的发动机效率和一次能源利用效率(PER)。结果表明:HPHP可减小发动机容量,当环境温度为-9～-1℃时,HPHP的发动机效率相比于GEHP提高了3.2%～9.4%;对于PER,HPHP与EHP相比于GEHP有较大的提高;当室外温度为-9～3℃时,与EHP相比,HPHP的PER比EHP提高了1.2%～9.5%,当温度继续升高时HPHP与EHP的PER较接近。因此从整个供暖季的能效角度考虑,HPHP系统相比于GEHP和EHP具有较大的节能潜力。     

燃气热泵系统的应用与分析

燃气热泵系统作为有效利用天燃气能源的重要零部件,在能源结构调整中显现出越来越重要的作用。结合燃气热泵系统的主要工作原理、组成及相关技术参数分析,对燃气类空调采暖系统分别进行分析和比较。     

燃气发动机热泵及性能分析

介绍了燃气发动机热泵系统的构成及其工作原理，说明燃气发动机热泵的使用可减少空调／供热的用电量，缓解由空调／供热引起的电力紧张状况，降低电网的峰谷差，同时可调节燃气消耗量的季节不均衡性，并有利于环境保护。根据空调／供热系统的不同方式，给出了比较这些系统能源利用率的统一指标——次能源利用率，并利用一次能源利用率分析了六种供热系统的能源利用率，分析结果表明燃气发动机热泵的一次能源利用率最高，可节省能源。文章对燃气发动机热泵的性能进行了测试，一次能源利用率达到1．76。     

Experimental study on performance of a biogas engine driven air source heat pump system powered by renewable landfill gas

The equipment configuration of a landfill gas (LFG) fueled biogas engine driven air source heat pump system was studied. The process flow for collecting and purifying LFG was analyzed, and the LFG collection and purification method was determined. An experimental apparatus was set up, and the effect of biogas engine speed variation on LFG consumption, exhaust fume temperature of biogas engine, recovered waste heat from exhaust fume and cylinder liner, coefficient of performance (COP) of the heat pump and primary energy ratio (PER) of the system were experimentally tested. The results indicated that LFG consumption and biogas engine exhaust fume temperature increased with biogas engine speed. When the biogas engine operated in the 70%–90% rated speed range, the system heat output and exhaust fume waste heat recovery rate would be relatively higher. In addition, the maximum COP and PER reached 4.2 and 1.4 respectively.     

天然气发动机驱动的水-水热泵的实验研究

建立了天然气发动机驱动的压缩式水-水热泵实验台,采用先进的测试手段,进行了各种工况及转速下的实验研究。结果表明在试验工况范围内,系统的一次能源利用率为1．13～1．79。并具有较好的部分负荷特性,从而证明了该装置的节能环保效果。     

沼气机压缩式热泵系统的构建与经济性分析

由沼气发动机驱动的热泵（BHP）除能够保证一般热泵功能外,还能够充分回收利用沼气发动机的余热。根据对BHP的系统构建及一次能源利用率（PER）的计算结果,分析BHP系统的经济性及其对环境保护的作用。结果表明：BHP系统在经济性及环保方面都具有明显的经济价值和现实意义。     

燃气机驱动的供热空调系统容量调节的研究

在采用冷负荷系数法计算我国典型气象地区负荷分布的基础上，对燃气机驱动的供热空调系统在不同压缩机转速下的变工况特性、变速容量调节性及其节能机理进行分析，得到了寻找根据室外温度条件对燃气机热泵系统的容量进行实时控制的压缩机转速变化规律的有效方法。     

Simulation and validation of a hybrid-power gas engine heat pump

Hybrid-power gas engine heat pump (HPGHP) combines hybrid power technology with gas engine heat pump, which can keep the gas engine working in the economical zone. In this paper, a steady-state model of the HPGHP in heating condition has been established, the optimal torque curve control strategy is proposed to distribute power between the gas engine and battery pack. The main operating parameters of the HPGHP system are simulated on Matlab/Simulink and validated by experimental data, such as operating temperature, coefficient of performance (COP), fuel-consumed rate, etc. Heating capacity and COP of the heating pump system are validated under different ambient temperatures and water flow rates. The simulation and experiment results shows acceptable agreement, the maximum difference is respectively 8.9%, 5.9%, 9.5% and 8.2% for engine torque, motor torque, reclaimed heat and fuel-consumed rate. Based on the simulation results, HPGHP has the lowest fuel-consumed rate of 283 g (kWh)⁻¹ at engine speed of 3000 rpm; the PER of HPGHP system is about 15.9% and 11.4% higher than the GHP under the same load in Mode C and D.     

Development of a residential gas absorption heat pump

A residential absorption heat pump system has been developed based on a new absorption pair. It uses R 123a (CCIF₂CHCIF) as the refrigerant and ETFE (ethyltetrahydrofurfylether) as the absorbent. The thermodynamic analysis of the new pair shows the potential of very good performance for heat pump duties.Actual tests show that heating coefficients of performance (COP) in the range of 1.50 are possible, so the system is very competitive with other heating and cooling technologies especially in more northerly climates.     

Electrochemical compressor driven metal hydride heat pump

In this study, a new metal hydride heat pump system driven by an electrochemical compressor was proposed. The system uses the electrochemical compressor to generate absorption heating and desorption cooling in two identical LaNi₅ reactors operating at different pressure levels. A thermodynamic model was developed to predict the system performance in terms of various parameters. Modeling shows EC compression efficiency has a great impact on system performance. The system is suitable for cooling application less than 200 W where mechanical compressors are the most inefficient. The high compression efficiency of electrochemical compressor could potentially make the cooling system more competitive than existing metal hydride heat pump systems.     

Thermal modeling of gas engine driven air to water heat pump systems in heating mode using genetic algorithm and Artificial Neural Network methods

The gas-engine driven air-to-water heat pump, type air conditioning system, is composed of two major thermodynamic cycles (including the vapor compression refrigeration cycle and the internal combustion gas engine cycle) as well as a refrigerant-water plate heat exchanger. The thermal modeling of gas engine driven air-to-water heat pump system with engine heat recovery heat exchangers was performed here for the heating mode of operation (in which it was required to model engine heat recovery heat exchanger). The modeling was performed using typical thermodynamic characteristics of system components, Artificial Neural Network and the multi-objective genetic algorithm optimization method. The comparison of modeling results with experimental ones showed average differences of 5.08%, 5.93%, 5.21%, 2.88% and 6.2% which shows acceptable agreement for operating pressure, gas engine fuel consumption, outlet water temperature, engine rotational speed, and system primary energy ratio.     

Rotational torsion fatigue failure of an engine driven fuel pump coupling

Between 2005 and 2007 serious flight safety concerns arose when a small fleet of single engine basic trainer aircraft experienced five critical failures of engine driven fuel pump (EDFP) couplings, and a further instance of a cracked coupling. Consequent investigations showed that the coupling fractures were likely to have been caused by a combination of reverse torsional loading and bending. Engine ground runs were then carried out to evaluate linear and torsional engine vibration levels in the drive train affecting the fuel pumps. Analysis of the vibration data indicated that engines, which had caused pump‐coupling failures exhibited high‐amplitude torsional vibration at certain power settings. The excessive vibration level was eventually attributed to detuning of the crankshaft counterweight dampers. This investigation resulted in a change to the maintenance practises on the aircraft in question and no fuel pump failures have occurred since December 2008.     

采用微通道换热器的热泵型空调器性能研究

基于对采用自行研制的微通道换热器的热泵型空调器的实测结果,计算分析采用微通道换热器的热泵型空调器的能效提升效果。结果表明,在保持换热面积一定的情况下,采用微通道换热器可以使热泵型空调器的制冷和制热的能效提高20％以上。