Development and Experimental Study of Air Source Heat Pump Water Heater

The principle and development prospect of air source heat pump water heat were introduced,as well as the designation of condenser (storage water tank),experimental study on installations was also carried out.The results showed that air source heat pump water heater was superior to conventional system.Under the operation of cooling and heating,heat pump comprehensive utilization equipment could improve heating performance,reduce energy consumption,and recycle condensing heat to provide hot water.

Performance and Optimization of Air Source Heat Pump Water Heater with Cyclic Heating

A new type of microchannel condenser applied in the air source heat pump water heater(ASHPWH)with cyclic heating was proposed in this study.The operating performance of the ASHPWH was frst tested.Then,the structure of the microchannel condenser was optimized with the implement of vortex generators.Finally,a numerical model of the ASHPWH was established and the optimized microchannel condenser was studied.The experimental results showed that the average coefficient of performance(COP)of the 1HP(735 W)ASHPWH reached 3.48.In addition,the optimized microchannel condenser could be matched with a 3 HP(2430W)ASHPWH with an average heating capacity of 10.30 kW,and achieving an average COP of 4.24,14.6%higher than the limit value in the national standard.

Performance analysis of air-water dual source heat pump water heater with heat recovery

A new air-water dual source heat pump water heater with heat recovery is proposed.The heat pump system can heat water by using a single air source,a single water source,or air-water dual sources.The water is first pre-heated by waste hot water,then heated by the heat pump.Waste heat is recovered by first preheating the cold water and as water source of the heat pump.According to the correlated formulas of the coefficient of performance of air-source heat pump and water-source heat pump,and the gain coefficient of heat recovery-preheater,the formulas for the coefficient of performance of heat pump in six operating modes are obtained by using the dimensionless correspondence analysis method.The system characteristics of heat absorption and release associated with the heat recovery-preheater are analyzed at different working conditions.The developed approaches can provide reference for the optimization of the operating modes and parameters.The results of analysis and experiments show that the coefficient of performance of the device can reach 4-5.5 in winter,twice as much as air source heat pump water heater.The utilization of waste heat in the proposed system is higher than that in the system which only uses waste water to preheating or as heat source.Thus,the effect of energy saving of the new system is obvious.On the other hand,the dimensionless correspondence analysis method is introduced to performance analysis of the heat pump,which also has theoretical significance and practical value.

Experimental Study of Energy-Saving Air-Conditioner with Hot Water

Energy-saving air-conditioner with hot water is an air source heat pump air-conditioner,which can also supply hot water.The hot water is heated by a double pipe condenser connected with an air-cooled condenser in series in the system.This experiment of the energy-saving air-conditioner was carried out in the enthalpy-difference air-conditioner laboratory.The hot water temperature and the compressor's discharge and suction pressure were recorded in the working condition,where the ambient temperature was at 43 ℃,35 ℃,21 ℃,7 ℃,and 2 ℃ separately.The results showed that the system operated stably and reliably.This system can supply 240 L hot water at 50 ℃ in the whole year,and its coefficience of performance(COP)is much higher than the conventional air source heat pump system.Its energy conservation was proved by comparing the thermal efficiency with other sourece water heaters.

Heating performance of a ground source heat pump system installed in a school building

The heating performance of a water-to-refrigerant type ground source heat pump system is represented in this paper under the actual working conditions of the GSHP(ground source heat pump) system during the winter season of 2008.Ten heat pump equipments with the capacity of 10 HP each and a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth were constructed.We investigated a variety of working conditions,including the outdoor temperature,the ground temperature,and the water temperature of inlet and outlet of the ground heat exchanger in order to examine the heating performance of the GSHP system.Subsequently,the heating capacity and the input power were investigated to determine the heating performance of the GSHP system.The average heating coefficient of performance(COP) of the heat pump was noted to be 5.1 at partial load of 47%,while the overall system COP was found to be 4.2.Also,performance of the GSHP system was compared with that of air source heat pump.

光伏光热联合双源热泵系统运行模式研究(1):最佳切换模式验证

讨论了光伏光热联合双源热泵系统制热运行的最佳切换模式。利用TRNSYS软件建立了仿真模型,对双源(水源、空气源)热泵系统性能系数(COP_(s))进行了计算,提出以某时刻空气源热泵模式或水源热泵模式运行COP_(s)较大者优先运行作为COP_(s)切换模式。通过前期实验结果验证了模拟结果的正确性,并与常规的集热水箱温度切换模式进行了对比实验,验证了COP_(s)切换模式的有效性。结果表明,该实验系统以COP_(s)最佳切换模式运行时发电量和发电效率较集热水箱温度切换模式分别提高了5.35%和1.73%,耗电量降低了17.03%,COP_(s)提高了4.91%。

光伏光热联合双源热泵系统运行模式研究(2):供暖季系统仿真研究

使用TRNSYS软件建立了光伏光热-双源热泵(PV/T-DSHP)系统的仿真模型。选取夏热冬冷地区某一近零能耗居住建筑作为研究对象,模拟研究了供暖季PV/T-DSHP系统在COP_(s)切换模式下的运行特性和能耗。结果表明:平均光电效率为15.08%,平均光热效率为33.05%;水源热泵运行模式下供暖季平均COP为4.55,空气源热泵运行模式下供暖季平均COP为3.19,PV/T-DSHP系统的平均COP_(s)为2.98;供暖季系统自满足率为61%。

太阳能-空气源热泵热水系统新型组合优化设计

太阳能-空气源热泵热水系统(solar-air source heat pump hot water system, SAHWS)常用于宿舍楼宇供暖,通过对系统参数的优化设计可显著提高系统能效性能与环境友好性。为得到一种综合考虑SAHWS经济、能源、环保与节能的优化方法,提出了一种新型组合优化设计策略,并利用TRNSYS软件搭建系统仿真模型,以西安、西宁、拉萨这3座不同太阳能资源等级城市为例,对SAHWS运行工况对比分析。结果表明:与常用生命周期成本设计相比,所提出的组合优化设计不仅降低了系统成本,还有着较低的系统能耗;组合优化设计的热泵能耗与工作小时数最短,且有最低的热损,在投资成本、系统季节性能因子、太阳能保证率以及碳粉尘、二氧化碳排放量均有较好表现。

住宅户内空气源热泵生活热水系统循环恒温能耗分析

基于3个住宅户型案例的空气源热泵生活热水系统,对系统配水管道采用循环恒温方式维持热水用水温度时的管道散热量进行计算评估,分析了循环恒温不同运行模式下的增量能耗和电耗,提出当前全装修住宅空气源热泵热水设备应集成管道恒温循环装置及控制装置等建议。

带气液调配蒸发器空气源热泵热水器的实验研究

气液调配蒸发器通过调整干度和质量流速实现传热性能提升。分别将两个管程布置为4-2-4-6-4(蒸发器1)和5-4-3-4-4(蒸发器2)的气液调配蒸发器用于热泵热水器中(分别为系统A和系统B)进行实验,并进行了对比研究。结果表明:相比于蒸发器1,蒸发器2制冷剂分布更均匀,且蒸发器侧压降减小了10.91%。在名义工况下,相比于系统A,系统B制热量减少1.69%,功率也减少1.45%,两个系统COP基本相同。系统B的排气压力比系统A小26.35~84.78 kPa,更有利于压缩机的安全运行;在不同的环境温度下,系统B的压缩机功耗均小于系统A,当环境温度为30℃时,系统B的性能比系统A提高了2.1%。

夏热冬冷地区空调冷热源配置的多目标优化

为实现“双碳”背景下清零建筑直接碳排放的目标,夏热冬冷地区建筑空调冷热源越来越多地采用空气源热泵加水冷式冷水机组的复合架构。其中,空气源热泵冬季供热,夏季与水冷式机组共同供冷。由于空气源热泵供冷能效较低,提高水冷式机组容量配置,尽可能使之分担更多的冷负荷,有利于降低系统供冷能耗,但系统投资也将随之上升。因此,有必要研究复合架构下空调冷热源配置的综合优化方法。利用层次分析法,计算空调冷热源系统的节能性、环保性、经济性、节材性等不同目标维度的权重,建立空调冷热源的综合优化目标函数。设计空调冷热源配置的优化流程,并以上海某办公建筑为例进行分析。结果表明,随着水冷机组容量的增加,空调冷热源系统的全年能耗降低,耗材生产能耗、折算年费上升,而碳排放呈先降后升的规律。多目标优化方法可以更好地实现各项指标之间的平衡,为相关研究及实际项目决策提供参考。

采用电子膨胀阀和毛细管的空气源热泵热水器性能对比实验研究

为研究不同节流方式对空气源热泵热水器性能的影响,分别以毛细管(CAP)和电子膨胀阀(EEV)作为节流元件研制了样机,通过实验对比研究其运行特征。结果表明:CAP系统的吸气过热度能稳定在1℃左右;CAP系统的排气温度相对更低,约比EEV系统低15℃;加热同样一箱水,CAP系统的制热速度更快;EEV系统的COP和全年性能系数(APF)均高于CAP系统,但在名义工况下CAP系统具有与EEV系统相当的制热COP。综合考虑制热性能及初投资等因素,可根据需要优先采用毛细管作为节流装置。

高校宿舍太阳能-空气源热泵复合热水系统设计与应用探讨

在当前积极倡导节能减排的政策要求下,可再生能源利用逐渐普及。以西安建筑科技大学学生宿舍太阳能-空气源热泵复合热水系统为例,阐述了复合热水系统的构成、工作原理,对太阳能集热系统、空气源热泵换热系统、热水供水系统等进行了设计计算,给出了集热器、热泵机组、集热水箱、供热水箱等主要设备的选型结果,提出了系统运行控制方案,并结合实际运行工况下的热性能数据,计算得到系统在不同季节的太阳能保证率、热泵能效比COP值,表明系统具有极大的节能性。

某温泉庄园热源方案技术对比分析

随着热泵技术的快速发展和煤改电政策的推进,空气源热泵的应用优势越来越凸显。以大连某温泉庄园热源设计为例,结合业主意愿和要求,提出三种热源方案:温泉水经板换换热的直供方案;温泉水板换换热和水源热泵联合供暖;采用空气源热泵供暖。对三种设计方案进行了技术经济对比分析,提出空气源热泵供暖方案是最经济的。在保证电力可靠,安全运行的同时,合理利用能源,提高了经济效益。

空气源-水蓄热-水源组合式热泵系统在西北沙漠地区供暖运行分析

针对西北沙漠地区冬季环境温度较低问题,为了满足现场生活区供暖需求,设计了一套组合式热泵系统:空气源热泵为第一级,结合水箱储热;水源热泵为第二级,提温的组合式热泵供暖系统,替代原燃气加热炉。通过对该系统在供暖季和极端工况下的运行参数统计、性能分析,系统供暖季平均COP为2.342,相较于常规热泵系统COP小于1.8,效率提升显著,能耗降低明显,年减少燃料气消耗19.66×10^(4)m^(3),减少碳排放量134.15 t,兼顾低温环境适应性和较高效率;同时每年减少运行费11.84万元。试验表明,组合式热泵系统可成为油田供暖技术经济均可行的选择之一。

太阳能与空气源热泵集成系统在医院生活热水供应中的应用与效益分析

文中以南昌大学第一附属医院象湖院区为例,对比分析了传统燃气热水系统与集成太阳能光热和空气源热泵系统,结果表明,后者在节能和经济效益上均优于前者。文中提出了改进系统设计和提升能效的策略,旨在为医疗行业太阳能光热技术的推广提供理论和实践指导,促进绿色能源在该领域的应用。

考虑经济性的北方农村地区低碳清洁取暖策略研究

大力推广清洁取暖是关系国计民生的重要工作,然而清洁取暖不是单纯的能源替代,特别在农村地区,同时需要考虑经济性和可推广性等。为此,提出了加装保温窗帘降低建筑整体热负荷,利用符合生活习惯的电热炕来满足局部热舒适需求,以及引入热泵热风机进行总体环境控制的策略。以山西农村某典型农宅为研究对象,利用TRNSYS对提出的清洁取暖方案进行模拟分析。结果表明,在取暖初期、室外温度最低时、取暖末期3个典型日均能够满足人体舒适性要求;在整个取暖期年运行费用可节约37.9%,费用年值没有显著的差异;同时SO_(2)、NO_(x)、PM_(2.5)和CO_(2)排放量分别降低了99.1%、92.1%、98.9%、89.4%。可为北方农村地区推广清洁取暖提供路线指导。

24h全日集中空气源热泵热水系统贮热水箱容积的分析探讨

在空气源热泵热水系统设计中,贮热水箱容积的计算至关重要。介绍并分析了现行标准规程贮热水箱容积的计算公式,指出了公式运用时可能存在的问题。针对空气源热泵定时运行、24 h全日集中热水供应系统,根据热泵运行时间与用水高峰持续时段的覆盖关系,分情况分析并推导了贮热水箱容积的计算公式。在设计取值范围内,对上述推导公式计算的贮热水箱容积进行了分析。提出了贮热水箱容积在方案阶段的估算建议值。

“空气源热泵-太阳能”热水系统在高校学生公寓的应用

学生公寓热水需求量大且用水时间较为分散,选择少污染且高效的热源形式,对高校的节能减排有重要的意义。空气源热泵辅助太阳能热水系统水温恒定,可全天候供应热水,满足阴雨天及冬季使用热水需求,智能化程度高,节能效果明显且项目回收周期短,可以在高校中推广使用。介绍山东某高校公寓实际运行的空气源热泵辅助太阳能热水系统及其控制原理;并通过对电热水器和单独采用空气源热泵制取热水方式的年耗电量计算,与实际运行项目的年耗电量比较,对其节能性进行分析。由于对系统各设备的启停采用了智能控制系统,能够对系统运行模式进行灵活调控,使得该系统比电热水器节电75%,比独立空气源热泵系统节电30%。根据2021年项目实际年收入,预计该系统回收周期为4.2年。

某民用建筑可再生能源热水系统设计分析

近年来,在“碳达峰、碳中和”的大背景下,国家及地方各级政府颁布了一系列节能降耗、降碳减排的政策,推动能源绿色高效智慧转型,促进可再生能源高质量发展。太阳能、热泵等可再生能源作为生活热水系统的热源具有清洁环保、节能低碳、可持续获取的优势,近年来在民用建筑的生活热水系统中得到了广泛的应用。以宜兴市某住宅建筑的集中式太阳能+空气源热泵热水系统为例,制定了系统运行控制策略,详细介绍了系统精细化设计思路及过程。对比传统燃气、电力能源,寿命期内能源费用比燃气节省55.33万元,比电力节省77.33万元,节能及环境效益明显,减少了烟尘、CO_(2)、SO_(2)及NO_(x)的排放量,为可再生能源热水系统的深化设计及应用发展提供参考。