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。     

太阳能辅助R744热泵系统在中原地区的性能分析

针对中原地区典型气象年(辐射极大)的冬季气象条件,通过所建立的跨临界循环热泵系统性能模拟平台,计算并对比分析了太阳能辅助R744跨临界循环及单一R744热泵系统在中原地区的运行特性;讨论了热水出水温度、传热窄点温差改变时系统制热性能系数和最优放热侧压力的变化规律。研究结果表明,在设定工况下,联合应用太阳能集热系统,R744热泵系统性能在冬季可得到大幅度提高,平均提高34.4%;热水出水温度低于70℃时,系统性能提高幅度超过36.0%;但传热窄点温差增大,系统性能有一定程度下降。     

分区蓄热水箱应用于太阳能热泵中的蓄放热分析

针对冬季太阳能辐射弱且不稳定的特点,提出一种应用于太阳能热泵的分区蓄热水箱,以水泵驱动蓄热水箱循环区与蓄热区的热量传递,并运用热力学原理对水箱循环区与蓄热区的运行状况进行模拟,分析了水箱两区在不同水泵体积流量下的逐时温度变化并与整体式水箱进行对比。结果表明,分区蓄热水箱克服了整体式水箱的热惰性,启动灵活,能在较短时间内达到热泵运行的理想温度,显著提高了系统的性能。     

双热源太阳池热泵技术的应用研究

对双热源太阳池热泵技术的应用进行了模拟研究.运用有限差分的方法,太阳池模拟结果表明,所储存的能量相对比较稳定,可为变负荷载荷供热;太阳池热泵技术的应用模拟结果表明,太阳池作为地位热源时,热泵制热的性能系数在4.08～4.87.若冬季太阳池作为低位热源的提热量为20 W/m2,完全能够满足冬季供暖时的温度要求.研究结果为实际利用提供了计算方法和重要依据.     

间接式海水源热泵系统动态运行能耗的模拟分析

由于大气温度同时影响着建筑物空调系统的冷热负荷和海水的温度,而海水温度的变化又会导致海水源热泵系统性能的改变,因此,海水源热泵系统的运行能耗同时受到大气温度和海水温度的影响。文章以青岛市某海水源热泵系统为例,以DeST软件模拟得到的建筑物逐时空调负荷为基础,模拟计算和分析了该系统在海水温度动态变化情况下的运行能耗。     

湖水源热泵退水对湖体温度场影响评价

为了评价南京地区某湖水源热泵系统退水对湖体温度的影响,建立了退水水流模型和考虑湖面综合散热系数的温度场模型。通过将水流模型和温度场模型耦合的数值模拟方法分析了湖水源热泵系统在夏季静风,夏季东风,冬季静风和冬季东北风4种典型运行工况下,热泵系统退水对湖体温度场的影响。4种典型工况下的数值模拟结果表明,湖水源热泵退水造成的湖水水温变化在地表水环境质量标准规定的人为影响限制范围之内。不同季节受湖面风速的影响,湖面综合散热系数的改变对湖体温度场分布的影响十分显著。     

跨临界CO2热泵系统性能研究

建立了跨临界CO_2热泵热水系统及其主要部件的数学模型并进行了模拟,利用自行搭建的跨临界CO_2热泵实验台进行了相关的实验研究。分析比较了气冷器的出口水温、气冷器的制热量与系统COP_h值(跨临界CO_2热泵系统)的仿真值与实验值,结果表明实验值与仿真值较为吻合,建立的系统模型准确性较高。利用仿真与实验的手段,研究了不同的冷却水流量和冷却水温度对跨临界CO_2热泵系统的性能影响。研究结果表明:系统运行时外部参数冷却水温度和流量及蒸发温度的变化将引起系统性能参数(制热量Q、系统COP_h值)变化,尤其是气冷器进口水温对系统性能的影响最大,为了保证气冷器中CO_2工质实现跨临界循环,降低气冷器进口水温是关键因素。     

带闪发器的两种补气热泵系统性能模拟研究

对热泵系统分别建立了中间补气和吸气补气两种热力学模型,模拟研究了系统的性能,并与常规热泵系统进行了对比。结果表明:混合后的吸气温度与吸气管路温度之间的差值Δt是影响吸气补气热泵系统的关键;中间补气热泵系统在各个性能上优于吸气补气热泵系统,但吸气补气热泵系统可以通过调节合适的Δt和补气量来提高系统性能;在不同的蒸发温度下,各热泵系统同一性能参数的变化趋势基本相同;蒸发温度在-10~-20℃范围变化时,与常规热泵系统相比,中间补气系统的最优COP提高了7. 53%~8. 90%;在Δt为0. 2℃的工况下,当蒸发温度从-20℃提升到-10℃时,吸气补气对系统性能的影响更显著。     

太阳能与空气源热泵联合供热水系统控制策略的研究

以长沙地区某宿舍建筑为例,基于TRNSYS软件建立了太阳能与空气源热泵联合供水的双水箱系统数学模型,模拟不同季节水箱内的水温变化及运行能耗特点,利用正交试验法分析集热器的质量流量、热泵启停温度和供水负荷等因素对系统运行能耗的影响,并与传统的双热源单水箱系统进行比较。结果表明:影响系统能耗大小的显著性因素,在夏季时为恒温水箱进水温度,在冬季时为热泵启停温度;与单水箱系统相比,双水箱系统运行能耗更低(夏季可降低45%、冬季可降低9.5%)。研究结果对指导太阳能热水系统的设计和优化控制具有重要意义。     

T2Well单井地下水源热泵水-热耦合数值模拟研究

以北京地区实际井参数刻画的单井地下水源热泵为研究对象,利用T2Well模拟器对单井系统地源热泵运行过程进行全面模拟,并对主要参数进行敏感性分析,探究对单井系统生产井温度、热突破时间的影响。距离井筒相同位置不同深度的点,埋深越大受回灌水温度的影响越小。每个运行周期结束时,温度场分布都能得到一定程度的恢复(同一周期内初始温度场相比)。水平方向渗透率同垂向渗透率的比值越大,越有利于回灌水在含水层中的运移,可有效保证热泵系统的取热温差。初步预计一个单井水源热泵系统能满足北京地区约1.5万m2面积建筑的供暖需求,约1.6万m2面积建筑制冷需求。     

双水位可控节水洁具装置的研究

介绍一种双水位卫生间洁具水箱节水型排水阀装置。本装置为串联式提拉阀,第一级为低水位阀门,第二级为高水位阀门,两级阀门控制两个档位的排水,以适用对大小便等冲污量不同的用水量要求．尤其适合于对旧水箱的节水改进。     

A novel thermal water pump for circulating water in a solar water heating system

This research purpose was to perform a parametric study of a novel thermal water pump well fitted in a simulated solar water heating system (SWHS). The SWHS was composed of a heating tank (HT), a hot water storage tank (ST) and an overhead tank (OT). The HT together with a specially designed valve act as a novel thermal water pump that gets power from hot water vapor and air pressure produced by a built-in electric heater in order to transfer heat from the HT to ST. The general operation of this pump has four stages for each cycle: heating, water circulating, vapor circulating and water supplying. The discharge water heads were varied with an increment of 0.25 m from 0.75 to 3 m. According to the experiment, it was found that the pump could operate at an average HT temperature of about 80–95 °C leading to 70–80 °C ST temperatures and 20–35 pumping cycles and consumed 17 MJ energy input during 9-h period. The overall thermal efficiency of the SWHS was 33–42% and the mean pump efficiency was about 0.005–0.011% depending upon the discharge heads.     

Hydrogen and fresh water production from sea water

A review of hydrogen production as a source of energy was made. Electrolysis was found to be the major technique of hydrogen production from sea water. A potential difficulty with this process is the chlorine and oxygen that are evolved at the anode. A new concept for hydrogen production from sea water by an electrochemical method was investigated. In this concept fresh water and hydrogen are produced simultaneously. The electric cell consists of a set of electrodes with each electrode suspended between two plastic membranes (cations and anions). Hydrogen is evolved from the cation compartment and chlorine gas from the anion compartment. Cost estimation and evaluation of the process were made.     

去离子水电解液与蒸馏水电解液的比较

简要介绍了去离子水的制备过程,分析了用去离子水作铅酸蓄电池硫酸稀释剂的好处。通过两种蓄电池 三充二放"试验、装车试验及经济效益分析,得出去离子水铅酸蓄电池更能提高铅酸蓄电池使用可靠性。     

太阳+海水=淡水

法国南锡化学工程实验室的化学家皮埃利戈夫,经过不断的失败和挫折后,终于研制成功一种结构简单、使用方便的太阳能淡化海水新装置,可大大节约淡化海水的成本。 在海湾地区,尽管海水取之不尽,但每个国家几乎都缺少淡水。虽然许多国家已建起海水淡化工厂,     

风能提水与节水灌溉技术

以风能为动力提水并利用地形自然落差发展节水灌溉技术，解决了无电偏远山区的缺水问题。介绍了风力提水原理、特点、适用及适宜的节水灌溉形式。     

Solar water pumping clean water for Sudan rural areas

The Republic of Sudan in Eastern Africa has one of the fastest growing economies in Africa. However, its remotely isolated rural areas pose problems to rural energy management and development because of poor road links with the urban centres, and remoteness from the national electrical transmission grid. Development of renewable energy sources, therefore, has a vast potential in Sudan. Solar energy, with excellent sunshine of over 3000 h per year, is of paramount importance, the applications of which are already quite siginficant and are growing at steady rate. Solar energy is suitable for small-scale water pumping in remote areas where the demand is regular, such as for drinking water, but it may also be used for irrigation. Most areas in Sudan have climates suitable for solar pumping. A review is given of the use of solar energy for water pumping to improve the living conditions of the population in rural areas and to develop techniques for utilization of solar energy in a tropical environment condition. Results, suggests that, solar powered water pumping must be encouraged, promoted, invested, implemented, and demonstrated by full scale in Sudan.     

空调冷凝水作为水资源的回收利用

理论分析了在户式空调、中央空调末端装置的空调冷凝水的产生量，介绍了冷凝水作为冷却塔补充水、景观灌溉、水景等用途及注意事项。     

From water to energy: The virtual water content and water footprint of biofuel consumption in Spain

Energy diversification and the use of renewable energy sources are key points in the European energy strategy. Biofuels are the most popular renewable resource option for the transport sector, and the European Union has established objectives that the Member States must adopt and implement. However, biofuel production at such a scale requires a considerable amount of water resources, and this water–energy nexus is rarely taken into account. This paper shows the strong nexus between water and energy in biofuel production and estimates the virtual water (VW) content and the water footprint (WF) from the raw material production that will be needed to reach the Spanish targets for biofuel consumption by 2010. The results show how the impact of such targets on the global and local water situation could be reduced through virtual water imports and, at the same time, how these imports could increase Spain’s water and energy dependence. Hence, in order to manage water from an integral perspective of the territory, the inclusion of biofuel consumption objectives should go hand in hand with measures to reduce the demand of energy in the transport sector.