水源热泵联合市政集中供热的系统设计方案及供热模式分析

针对济南市某住宅小区集中供热负荷不足的情况，提出水源热泵联合市政集中供热的系统设计方案及供热模式，并结合实际项目进行了研究。结果显示：经济性运行方案下，建议平电、谷电时段采用热泵供热，峰电时段采用市政集中供热系统供热模式；统筹经济性稳定性运行方案下，建议采用市政集中供热系统负担50%热负荷+水源热泵系统负担50%热负荷的供热模式，该供热模式下单位面积热指标为38 W/m2,水源热泵能效比为3.73，运行效率较高。为多种热源联合供热运行模式分析提供了参考思路。     

水源热泵供暖在承德市受欢迎

近年来，承德市各有关部门充分利用水资源优势和建筑沿河的特点，大力推广水源热泵技术与建筑一体化，在供暖、制冷和生活用水方面收到了良好的效果。目前有市公安局办公大楼、银监局办公大楼及住宅小区、承德司达石油装备开发公司办公楼、丰宁宏丰住宅小区等40处机关、单位、宾馆、居民小区共50万m2应用了水源热泵，约占全市供热总面积的7％左右，不仅为节能减排作出了贡献，还补充了大供热的不足。     

地表水源热泵在湖南地区的应用分析

本文分析了湖南地区气候特点、水资源状况以及水源热泵系统对水源系统的要求，以湖南省湘潭市某地表水源热泵空调系统为例，对地表水源热泵系统在湖南地区的应用进行了实例分析。在湖南地区应用水源热泵空调方式效率高、节能且经济，符合当今世界可持续发展的要求，可以作为湖南地区冬季供暖夏季制冷的长久良策。     

抚顺地区水源热泵的经济性分析及应用

抚顺地区具有丰富的水资源,根据水源热泵系统的工作原理,提出在该地区采用水源热泵替代燃煤集中供热的采暖方案。以抚顺地区的工程为例,把地下水水源热泵机组与燃煤集中供热锅炉进行经济性和环保性分析比较。结果表明:水源热泵方案是可行、经济、而且更加环保,应在抚顺地区大力推广。     

提高水源热泵机组效率的技术条件分析

以热力学完善度为评价指标,分析水源热泵在标准工况下各部件的不可逆损失程度,其中由压缩机和换热器引起的不可逆损失占总不可逆损失的80%以上。在此基础上,针对水源热泵的特点,对几种能提高其能效水平的技术进行定性和定量分析,结果表明均能有效提高机组的热力学完善度。对采用这些技术的水源热泵机组进行的测试中,制冷,45℃、55℃制热工况下,性能系数分别达到6.64、4.79和3.99。对市场上的部分水源热泵产品样本进行统计分析,结果表明制冷和制热工况的性能水平较低,热力学完善度平均值分别为0.270和0.423,绝大部分产品的性能提升空间超过20%。     

地表水源热泵的技术经济与环保效益分析

地表水源热泵暖通空调领域的前沿技术,具有极其广阔的应用前景.提出了地表水源热泵应用的节能、经济、环保三类共15个评价指标及其计算确定方法,并对我国102个城市的各项指标进行了预测计算,结果表明地表水源热泵技术在我国南方地区经济效益显著,在北方地区则环保效益突出,而且各项效益还与城市的水源、规模、形状、气候、地理位置等因素密切相关.地表水源热泵技术具有巨大的社会效益和经济效益,应该加大推广力度.     

夏热冬冷地区闭式湖水源热泵系统的运行特性分析

建立了闭式湖水源热泵系统的数学模型,根据逐时负荷与逐时气象参数对位于长沙的某闭式湖水源热泵系统的动态特性进行模拟,分析了封闭水体的深度和面积对制冷及制热工况下机组进液温度的影响。分析结果表明:在其他条件不变的情况下,增加水体的深度对系统的供冷性能有利,对系统的供热性能反而不利;增加水体的面积对提高系统供冷性能的作用较小,对提高系统供热性能的作用较大。在一些与长沙气候类似的地区应用闭式湖水源热泵系统时,只要换热盘管长度适当,换热流体可以不采用防冻液。     

岩溶含水层地下水源热泵运行对地下水温度场的影响

为探究岩溶含水层水源热泵运行期间地下水温度场变化规律,以武汉市某场地地下水源热泵系统为例,基于有限元数值模拟软件FEFLOW,分别模拟了水源热泵空调制冷和制热期间抽水-回灌目的含水层中的渗流场和温度场,并对表征岩溶发育的重要参数储水系数和孔隙度进行敏感性分析。模拟结果表明,地下水源热泵运行仅影响回灌井附近地下水温度,不会对区域含水层温度产生影响;而表征岩溶发育的典型参数储水率和孔隙度,对模拟结果的影响不大。     

向撒哈拉大沙漠要能源

“沙漠技术工业行动计划”项目上马 撒哈拉沙漠是世界上最大的沙漠,东西长达5600km,南北宽1600km左右,面积大约960万km2,约占非洲总面积的32％。     

南昌地区地下水源热泵的应用与分析

介绍了地下水源热泵的工作原理,结合南昌地区的水文地质情况,分析了影响地下水源热泵系统运行效果的因素,以及系统在应用过程中需要注意的问题,并对南昌地区发展地下水源热泵提出了建议。     

Technology line and case analysis of heat metering and energy efficiency retrofit of existing residential buildings in Northern heating areas of China

The building area in northern heating areas accounting for 70% of the total land area in China is 6,500,000,000 m². The average heating energy consumption in northern China is 100–200% times more than developed countries in the same latitude. This paper introduced firstly the heat metering and energy efficiency retrofit background of existing residential buildings in northern heating areas of China organized by mohurd and MOF, and then put forward the total principle and contents of retrofit. Through analyzing some retrofit cases in Germany, Poland and China, some technological experiences were summarized and finally a technology line suitable for heat metering and energy efficiency retrofit of existing residential buildings in northern heating areas of China which involved retrofit for heat metering and temperature regulation of heating systems, heat balance of heat source and network, and building envelope was described to provide a systematic, scientific, technological guide for the retrofit projects of 0.15 billion m² in “the Eleventh Five-Year Plan” period.     

Geothermal district heating for reno, Nevada, U.S.A.

The City of Reno is one of the most obvious candidates for geothermal district heating in the United States. Lying within a helt of major thermal anomalies, it has within its boundaries the Moana Hot Springs geothermal reservoir and probably other reservoirs, and only 14 km to the south is the major reservoir at Steamboat Hot Springs.This paper discusses the alternative heat sources that can be used, and selects Steamboat as the most conservative choice for a “worst-case” analysis of the details and economics of a model district heating system. A closed 16 km transmission loop between Steamboat and downtown Reno is envisaged, carrying 121°C water in the supply line and 65°C in the return line. This loop is isolated by heat exchangers from both the 176°C geothermal fluids at the Steamboat end of the line, and from the Reno user systems at the other. Detailed analysis of thermal demand densities in different parts of the City led to a model distribution network 48 km long, that serves the optimum grouping of zones of concentrated heat users. A large proportion of existing heating systems are hydronic and retrofitting of the selected buildings to the district heating system is relatively straightforward. Total peak load for the proposed system is 138 MJ s⁻¹ (139 MW_t) and annual consumption is 1.1 × 10¹⁵ J. Capital costs total about $55.4 million, in 1981 dollars. The economic analysis shows this system could provide considerable savings relative to the cost of natural gas, if revenue bond financing at 13% is employed for the construction and startup of the system. Even more favorable economic results could be achieved if a geothermal resource could be developed closer to downtown Reno, eliminating the high cost of the 16 km transmission pipeline. Reducing the service area to the most concentrated area of heat use in downtown Reno produces an even more viable system, about half the size of the full system.     

Optimization study on a solar-assisted air source heat pump system with energy storage based on the economics method

Currently, hybrid renewable energy systems with thermal energy storage have various advantages and are widely used. This paper investigated the performance of a solar-assisted air source heat pump system with energy storage (SASHPS-ES) in Beijing, China, and proposed an optimal operation mode based on economic evaluation. The results indicate that with the optimal heat storage ratio of 50%, the rated capacity of the air source heat pump (ASHP) of the SASHPS-ES system can be reduced by 16.7%, decreasing its annual total cost by 26.5% under a peak-valley electricity price policy. The price of 620¥/m² is critical for the solar collectors. The economics of SASHPS-ES is better than that of an air source heat pump system with energy storage (ASHPS-ES) when the price of the selected solar collector units is less than this critical price (without subsidies from the government). In the current local market, the promotion of SASHPS-ES systems and other solar energy applications requires government subsidies for a period of time. The results can guide the utilization and popularity of SASHPS-ES in China.     

Improved underground heat exchanger by using no-dig method for space heating and cooling

This paper describes experiments and analyses on an improved underground heat exchanger by using a no-dig method for the purpose of the cost reduction of a space heating and cooling system using underground thermal energy. First, the improved underground heat exchanger was installed on the campus of Hokkaido University, and it was shown that a ground source heat pump system utilizing the heat exchanger was sufficient for space heating and cooling. Second, evaluation program of the heat exchanger was developed, and the program was verified to give good predictions by comparing with experimental results. As a result of system simulations, an energy reduction for a system installation relative to a conventional vertical earth heat exchanger reached 78%. The primary energy reduction rate including the system installation and operation relative to a typical air source heat pump was 29%.     

CO2 payback–time assessment of a regional-scale heating and cooling system using a ground source heat–pump in a high energy–consumption area in Tokyo

We present an assessment of installing a regional heating and cooling system in the Nishi(West)-Shinjuku area of Tokyo, Japan. In this assessment, we estimate the CO₂ payback–time, when air source heat–pumps (ASHP) are replaced with a ground–source heat–pump (GSHP) system. We calculate CO₂ emissions from transportation of the cooling tower, materials for the underground heat exchanger, and the digging loads and transportation loads incurred when the GSHP system is installed to replace the air source cooling system. The total CO₂ emission from the installation of the GSHP system was estimated to be 67,701t-CO₂, with 87% of the CO₂ emissions resulting from the digging process. CO₂ emissions from the operation of the GSHP system were estimated from the total energy-efficiency of the system and the heating and cooling demand in Nishi-Shinjuku area. Using the GSHP system, 33,935t-CO₂ would be emitted per year. We estimate that using the GSHP system would result in a reduction of 54% of the CO₂ emissions, or 39,519t-CO₂ per year. From these results, the CO₂ payback–time for replacing the conventional ASHP in the 1 km² studied region with the GSHP system is assessed to be 1.7 years.     

Feasibility study of a district energy system with seasonal water thermal storage

In this paper, performance of three types of district heating/cooling and hot water supply system with natural and unused energy utilization were examined by using system simulation. An area zoned for both commercial and residential buildings was chosen for this study. The first system is the conventional system in which an electric driven turbo chiller and a gas-fired boiler are installed as the heat source. This is considered as the reference system. Two alternative systems utilize waste heat from space cooling and heating. One is designed based on short-term heat recovery and the other employs the concept of an annual cycle energy system (i.e. seasonal heat recovery). All of the three systems use solar thermal energy for hot water supply to the residential zone. The index for evaluation is the coefficient of performance of the overall system, based on primary energy. As a result, it was found that the seasonal storage system could decrease the energy consumption by about 26% and the short-term heat recovery system could decrease it by about 16% compared with the reference system. In designing the heat recovery system, a balance of cooling/heating demand is an important factor. Therefore a sensitivity analysis of performance of the overall system and the seasonal thermal storage for several load patterns was performed. From these results, it was found that if the amount of heating/cooling demand were well balanced, an improvement of energy performance could be achieved and the utilization factor of the seasonal tank would become higher. Furthermore, the volume of the seasonal storage tank could be reduced.     

光伏/光热-地源热泵联合供热系统运行性能研究

为解决太阳电池的发电效率随温度升高而下降以及地源热泵系统供热引起的土壤热失衡问题,以典型居住建筑的光伏/光热-地源热泵（PV/T-GSHP）联合供热系统为研究对象,基于TRNSYS软件,采用土壤温度、地源热泵机组季节能效比、光伏发电效率和太阳能保证率为评价指标,对该联合供热系统进行运行性能分析。研究结果表明：夏热冬冷地区（以长沙为例）太阳能保证率相对较高,PV/T组件面积为满屋顶最大化安装（900 m²）时,第20年末土壤温度相比初始地温仅升高0.8 ℃,热泵机组季节能效比约为5.1,太阳能保证率为97.0%~98.7%;不同气候地区的太阳能保证率与PV/T组件面积和建筑全年累计供热量有关,通过定义单位建筑全年累计供热量PV/T组件面积指标,得到中国不同气候地区的太阳能保证率与该指标的耦合关系,回归方程的决定系数R²为0.983,得出在已知建筑全年累计供热量和太阳保证率设计目标值的条件下所需PV/T组件面积的计算方法。PV/T-GSHP联合供热系统的全年运行能耗显著小于平板太阳能集热器-地源热泵联合系统（最小降幅为沈阳,49.7%）,远小于空气源热泵（最小降幅为石家庄,79.8%）和燃气壁挂炉（最小降幅为沈阳,65.1%）。     

涡旋压缩机闪发器热泵系统的试验研究

介绍了涡旋压缩机闪发器热泵系统,并在结构特点方面与对应的过冷器系统作了比较。对研制的闪发器热泵系统原型机进行了试验研究和性能分析。结果表明:随蒸发温度的降低,原型机的制热量有所减少,但减少的速度明显低于普通热泵系统,压缩机耗功有所增加,但增加的幅度不大;闪发器系统在低温工况下比过冷器系统可以更有效提高空气源热泵的低温制热性能,是寒冷地区用小型空气源热泵比较适宜采用的系统。     

基于地下水污染风险模糊评价模型及其应用

基于地下水资源供给功能,选取地下水防污性能和污染荷载等级作为评价因子,引入模糊识别概念,构建了地下水污染风险模糊评价模型,并将该模型应用于天津市地下水污染风险中。评价结果表明,天津市地下水污染风险很高、较高、稍高、略高、略低的面积分别为454、3 678、4 831、2 619、59km2,污染风险很高区分布在市区南部近郊一带、污染风险较高区分布在市区北部郊区、津南、塘沽南部、大港南部、静海东部和宝坻北部,与当地实际情况相吻合,可见所提模型可行、有效。     

Genesis of the plutonic-hydrothermal system around quaternary granite in the kakkonda geothermal system, Japan

The Kakkonda plutonic-hydrothermal system has as its heat source the Quaternary Kakkonda granite. The Kakkonda granite has a thick (1.3 km) contact-metamorphic zone, known mainly from the geothermal survey well WD-1a (total depth: 3729 m) drilled by the New Energy and Industrial Technology Development Organization (NEDO). The Kakkonda granite is a stock several tens of square kilometers in area with an upper contact about 1.5–3 km deep. It is a composite pluton varying from tonalite to granite. The early-stage granitic rocks are slightly metamorphosed to biotite grade by late-stage granitic rocks. K-Ar ages of separated minerals from the granitic rocks in both stages show the same cooling ages of 0.24–0.11 Ma for hornblende, 0.21–0.02 Ma for biotite, and 0.14–0.01 Ma for potassium feldspar. These are the youngest ages for granite in the world. The K-Ar ages become almost zero at 580°C for biotite and potassium feldspar, and at 350°C for illite. The Kakkonda granite intruded into a regional stress field in which the minimum principal stress was ENE–WSW and nearly horizontal. The regional stress field coincides with that of a previously recognized F2 fracture system before 0.4–0.3 Ma. Both stages of the Kakkonda granite and the contact aureole are fractured by recent tectonism, resulting in a zone of hydrothermal convection from about 2.5–3.1 km depth up to the surface. The boundary between the zone of hydrothermal convection and the underlying zone of heat conduction occurs 250–550 m below the upper contact of the Kakkonda granite, and has a temperature of 380–400°C.