燃气热泵应用分析

燃气热泵(GHP)是一种节能、环保、经济的空调系统形式,并可以平衡大中城市的燃气和电力使用负荷。本文对燃气吸收式热泵(GAHP)的应用进行了简单分析,并重点分析了燃气发动机驱动热泵(GEHP)与电动热泵(EHP)在系统结构、技术性能、投资、运行等方面的应用特点。     

Modelling of a water-to-air variable capacity ground-source heat pump

The present work aims at presenting the development of a performance-based model of a water-to-air variable capacity ground-source heat pump. The main challenge is to apply the recommended control strategy to vary the speed of the compressor for each mode of operation and to be able to switch from one mode to the other. A series of verification tests tend to confirm that the speed control strategy has been correctly implemented. The proposed model is used in annual simulations of a residential system equipped with a variable capacity ground-source heat pump. In this case, the seasonal performance factor (SPF?=?ratio of the annual energy requirement for heating, cooling and domestic hot water (DHW) over the annual total energy consumption) is 3.64. The corresponding value for a conventional system composed of a fixed capacity heat pump operating in on–off mode and a separate electric DHW tank is 2.60.     

地源热泵-燃气锅炉供暖系统的动态经济评价

针对燃气锅炉能源利用率偏低、废气排放多等问题,结合工程实际,利用经济分析的方法,对燃气锅炉供暖系统和地源热泵供暖系统分别从初投资、年运行费用、维护费用等方面进行分析。结果表明,地源热泵系统的初投资比较高,但由于运行费较低,根据费用年值及费用现值的计算,地源热泵系统在整个寿命期内的费用明显低于燃气锅炉供暖系统,因此,地源热泵系统比燃气锅炉系统具有更高的经济效益。     

燃气机热泵系统不同联供运行模式一次能源利用率的分析

分析了燃气机热泵热电冷三联供系统节能的热力学原理及应用优势,探讨了不同季节采用不同的联供运行模式一次能源利用率PER的情况,并就影响PER的主要因素——废热回收率、热泵性能系数及用于发电的燃气能量占燃气总能量的比例的变动效应进行了模拟计算,给出了燃气机热泵不同联供运行工况下PER的对比及规律。     

Economic and environmental evaluation of micro CHP systems with different operating modes for residential buildings in Japan

The growing worldwide demand for less polluting forms of energy has led to a renewed interest in the use of micro combined heat and power (CHP) technologies in the residential sector. The operation of micro CHP system results in simultaneous production of heat and power in a single household based on small energy conversion units. The heat produced may be used for space and water heating and possibly for cooling load if combined with an absorption chiller, the electricity is used within the house.In this paper, two typical micro CHP alternatives, namely, gas engine and fuel cell for residential buildings, are analyzed. For each facility, two different operating modes including minimum-cost operation and minimum-emission operation are taken into consideration by employing a plan and evaluation model for residential micro CHP systems. The analysis results show that the fuel cell system is recognized as a better option for the examined residential building from both economic and environmental points of view. With the operation considering optimal economic benefits, annual energy cost is reduced by about 26%. On the other hand, while maximizing the environmental merits, annual CO₂ emissions are reduced by about 9%.     

某制药公司制冷站设计

比较了该制冷站3种设计方案的初投资、年运行费用和占地面积后,确定采用螺杆式压缩机水源热泵机组系统,为制药生产提供冷却水,同时作为空调冷热源。实际运行表明,该方案可有效降低能耗,具有良好的经济效益。     

Energy savings potential of a desiccant assisted hybrid air source heat pump system for residential building in hot summer and cold winter zone in China

In hot summer and cold winter zone in China, air conditioning system has four running modes yearly including cooling with dehumidification, cooling, dehumidification and heating in residential buildings. The conventional air source heat pump (ASHP) system is not designed to independently control temperature and humidity, and is not very suitable for the dehumidification mode in the view of building energy consumption. A novel ASHP system combining radiant cooling/heating for residential buildings was presented. The main feature of this hybrid ASHP system is that desiccant wheel and cooling coil accomplish dehumidification process together, and the regenerative heat needed by the desiccant wheel is supplied by the condenser dissipated heat. Based on simulation studies and performance analysis, this paper predicts the primary energy consumption of the hybrid ASHP system in comparison with the conventional ASHP system during the cooling and heating seasons. It was found that primary energy requirement can be reduced by more than 8% in cooling with dehumidification mode, by 50% in dehumidification mode, and by more than 14% in heating mode. The study results prove that the hybrid ASHP system can keep great energy saving and running cost saving yearly, especially in the dehumidification process.     

Comparison of natural gas driven heat pumps and electrically driven heat pumps with conventional systems for building heating purposes

Electrically driven heat pumps achieve good efficiencies for space heating. If heat pumps are driven directly by a combustion engine instead of an electric motor, losses attributed to the production and transport of electricity are eliminated. Additionally, the use of the combustion engine's heat leads to a reduced temperature difference across the heat pump. This article presents annual efficiencies of these systems and compares internal combustion engine and electrically driven heat pumps in terms of primary energy consumption and CO₂ emissions. Because heat pump performance depends strongly on the heating circuit's flow temperature level, the comparison is performed for air-to-water and geothermal heat pump systems in two cases of maximum flow temperatures (40 °C and 60 °C). These temperature levels represent typical modern buildings with large heating surfaces and older buildings with high-temperature radiators, respectively. In addition to the different heat pump setups, conventional space heating systems are included in the comparison. The calculations show that natural gas-driven heat pumps achieve about the same efficiency and CO₂ emissions as electrically driven heat pumps powered with electricity from the most modern natural gas-fired combined cycle power plants. The efficiency of such systems is about twice that of conventional boiler technologies.     

基于DPSSHP的分布式供能系统在赣南地区的研究

赣南地区城市污水排放量较大,工业废水富含大量余热。发展基于直接式原生污水源热泵(Direct Primary Sewage Source Heat Pump,简称DPSSHP)的分布式供能系统,向建筑供冷供热,将大大降低建筑空调采暖能耗。根据赣南地区实际情况,提出了DPSSHP系统针对不同类型建筑的应用规划。选取了地下水源热泵,大型螺杆式冷水机组+燃煤锅炉,风冷式空气源热泵、DPSSHP,从系统初投资、运行费用、单位面积运行成本等方面进行经济性比较,得出DPSSHP较为经济。     

燃气机热泵性能系数随压缩机转速变化的研究

分析了压缩机转速变化对燃气机热泵制冷量、制热量及压缩机输入功率的影响。研究了燃气机热泵性能系数随压缩机转速变化的规律,调节压缩机转速可实现燃气机热泵的变负荷运行,尽管性能系数略有下降,但下降幅度较为平缓,且在较大范围内变化很小。     

Saving energy in the heat-pump air conditioning system driven by gas engine

The main functions of the heat-pump air conditioning system driven by gas engine (GEHPAC) are to maintain the room temperature and control the humidity of the room. In summertime, the air can be reheated by the waste heat water from the gas engine, while the air can be reheated and humidified by the waste heat water in winter. Reducing or displacing electrical heating requirements can achieve the greatest opportunity for significant energy savings. This paper, therefore, aims to improve the energy performance of the AC system by using the waste heat from the gas engine. The mathematical model for the second heat exchanger, the sprayed room, the mixed air, was used to research the GEHPAC. Explicitly, we investigated the influence of various factors including the outdoor air temperature and humidity in summer and winter. Results from the analysis show that the GEHPAC can save more energy than the electricity engine heat pump. The GEHPAC runs beautifully in part load mode. PERx is higher in winter than in summer. The maximum PERx is over 1.6 in summer, while over 1.9 in winter. The GEHP which can control the room humidity can be used in more areas than the common GEHP.     

An aquifer thermal storage system in a Belgian hospital: Long-term experimental evaluation of energy and cost savings

Over a three years period, an aquifer thermal energy storage system was monitored in combination with a heat pump for heating and cooling of the ventilation air in a Belgian hospital. The installation was one of the first and largest ground source heat pump systems in Belgium. Groundwater flows and temperatures were monitored as well as the energy flows of the heat pumps and the energy demand of the building. The resulting energy balance of the building showed that the primary energy consumption of the heat pump system is 71% lower in comparison with a reference installation based on common gas-fired boilers and water cooling machines. This corresponds to a CO₂-reduction of 1280 ton over the whole measuring period. The overall seasonal performance factor (SPF) for heating was 5.9 while the ATES system delivered cooling at an efficiency factor of 26.1. Furthermore, the economic analysis showed an annual cost reduction of k€ 54 as compared to the reference installation, resulting in a simple payback time of 8.4 years, excluding subsidies.     

京燕饭店冷热源节能改造效果分析

在满足饭店功能需求的前提下,根据饭店的自身条件,对冷热源形式从技术可行性、运行经济性、施工条件、国家的能源政策以及与现有冷热源系统的结合等多方面进行分析,确定了污水源热泵的冷热源形式。通过改造前后的对比分析,改造后在室内舒适度明显提高的基础上,能源费用年节约109．78万元,取得了可观的经济效益。     

利用温频法对空调冷热源进行经济分析及选择

以天津某五星级酒店为例,采用温频法(BIN法)和费用年值法,比较土壤源热泵对传统型电制冷、集中供热组合和吸收式直燃机3种空调系统冷热源进行经济性分析。结果表明,虽然地源热泵初期投资最大,但是年运行费用在3种方案中最低,具有很好的经济性。     

武汉地区地源热泵系统的应用调研与发展前景分析

对武汉地区地源热泵工程进行了较全面的调研,根据调查情况汇总分析了地源热泵工程分布特点、运行特性和经济环境效益,并指出应用地源热泵技术的多方面技术和经济优势,揭示了利用地源热泵技术在武汉地区实施供热、供冷具有良好的条件和发展前景.     

太阳能热泵供热系统的应用及经济性分析

以0.7 MW的供热功率为评价标准,分别对太阳能热泵、燃油锅炉、燃气锅炉和电加热锅炉四种供热系统进行了初期投资、运行费用、燃料价格等因素的综合技术经济分析与评价,评价结果表明：太阳能热泵供热系统的综合效果最好,适合在青岛推广应用。     

燃气机热泵在夏热冬冷地区应用的经济性分析

以上海地区某独立的两层结构别墅为对象,考虑了燃气机热泵、电驱动空气源热泵与电热水器及燃气热水器组合3种方案,比较了三者在夏季制冷、冬季供暖、制备生活热水时的全年能耗及运行费用。在生活热水产量相同的情况下,燃气机热泵的能耗和运行费用均低于电驱动空气源热泵与电热水器及燃气热水器组合方案,经济性显著。     

太阳能热泵-地板辐射供热系统实验研究

实验研究了太阳能热泵-地板辐射供热系统的性能,并与燃油、燃气锅炉集中供热系统进行了经济性分析比较。实验结果表明,热管真空管集热器的集热效率为64·4%,U形管真空管集热器的集热效率为59%,热泵机组的能效比为3·08;室内温度变化相对机组供热时间滞后3h,有利于采用间歇运行方式降低运行费用。经济性分析结果表明,在青岛地区为节能型建筑供热时,该系统的单位面积费用年值介于燃气、燃油锅炉集中供热之间。     

住宅建筑中污水源热泵技术的应用研究

本文阐述了污水源热泵系统的特点和形式，分析了污水源热泵采暖与生活热水系统在住宅建筑中的应用，包括方案设计、技术参数分析、经济性分析。结果表明，污水源热泵系统投资略高，但运行费用低，回收期短。     

土壤源热泵系统热平衡问题的讨论

土壤源热泵具有节能与环保的特点．近年来发展迅速,但在应用中存在冷热负荷不平衡的不利因素。这种不平衡会导致热堆积。引起整个系统性能的降低。本文介绍了针对不同情况的解决方法,如冷却塔辅助散热装置,太阳能-土壤源热泵混合系统等。并提出了亟待解决的新问题。