连续稳定循的三效吸附式热泵单元——三效冷环的设计和原理分析

设计了连续而又稳定循环的三效吸附式热泵单元－－三效冷环，使各吸附床的吸附循环之间具有先后连贯性，既可避免吸附床的过热，又能消除热泵输出端的不稳定工作状态，使得热泵系统的ＣＯＰ值、ｙｏｎｇ效率以及各级附循环的效率均有显著提高。此外，单元化使三效冷环易于长期维持真空度，便于根据余热量的大小进行并联组合成较大的热泵系统。     

连续稳定循环的三效吸附式热泵在两种工况下的COP值计算

设计了连续而又稳定循环的三效吸附式热泵单元－三效冷环，由于各吸附床的吸附循环之间具有先后连贯性，因此既避免了吸附床的过热，又消除了热泵输出端的不稳定工作状态，使得热泵系统ＣＯＰ值，Ｙｏｎｇ效率以及各吸附循环的效率比双效和单效系统有显著提高，重点分析了回收和不回收降温，吸附热时三效吸附式热泵比之与其它系统所存在的优越性。     

连续稳定循环的三效吸附式热泵在两种工况下的COP值针算

设计了连续而又稳定循环的三效吸附式热泵单元——三效冷环，由于各吸附床的吸附循环之间具有先后连贯性，因此既避免了吸附床的过热，又消除了热泵输出端的不稳定工作状态，使得热泵系统的ＣＯＰ值、■效率以及各吸附循环的效率比双效和单效系统有显著提高。重点分析了回收和不回收降温、吸附热时三效吸附式热泵比之与其它系统所存在的优越性。     

采用床内强制对流进行传热传质的固体吸附式循环分析

采用一维两温度模型，以活性炭纤维－氨为工质对，模拟计算了对流热波循环的吸附床加热过程和冷却过程中床内的温度分布和变化趋势，并分析计算了对流热波循环的性能参数。系统的回热率达０．４，热泵效率达１．７８，热泵系统的能量密度为１６１６Ｗ／ｋｇ。对系统加以优化，可获得更高的回热率和ＣＯＰ。     

三效溴化锂吸收制冷循环的参数优化

三效吸收循环是提高现有单效和双效吸收循环性能的一个发展方向。本文建立了使用溴化锂水溶液在做工质的三效吸收制冷循环模型,并进行了性能比较计算。结果表明：并联流程涵环的性能系数（ＣＯＰ）最高。同时对并联流程和串联流程的三效吸收循环分别进行了系统发生压力和溶液分配率的性能系数以及经济性能指标的优化计算,为三效吸收循环的最优设计提供理论依据。     

利用热管强化吸附床内的传热传质

为了强化吸附式制冷吸附床内的传热传质，设计了利用高效传热元件热管作为内翅片的吸附床。在能量守恒关系和吸附平衡方程的基础上建立了吸附床的数学模型，并对此模型用数值方法进行了求解。求解结果表明利用热管元件可以显著的改善吸附床内的传热传质过程，缩短了吸附式制冷的循环时间，提高了系统的效率，该数学模型为吸附床的设计参数的选择和优化等提供了依据。     

三效MVR与三效蒸发技术的能耗对比分析

对于海水淡化过程中的高能耗问题,将多效蒸发和MVR工艺相结合,提出多效MVR节能工艺的新思路。介绍了三效MVR蒸发系统的工作原理,用人工配制的氯化钠溶液模拟海水,以1 t/h氯化钠溶液为例,对三效MVR和三效蒸发技术进行能耗对比分析。分析结果显示,三效MVR蒸发系统每年可节省308 697.6元的加热蒸汽费用,并且还省去了末效蒸汽冷凝的装置,因此每年还可节省85 564.8元的冷凝水费用,相当于节省了63.6%的标准煤。     

连续回热型吸附式空调/热泵性能改进试验研究

研制了一台连续回热型吸附式空调/热泵,对吸附床设计进行了改进,并在样机上采取一系列控制措施,使工况稳定,通过改变热源温度、蒸发温度、循环周期等参数,获取多组实验数据,该样机在100℃热源驱动下SCP达到150W/kg,COP达0.4。     

吸附式海水淡化循环热力学分析

建立双床吸附海水淡化基本循环的数学模型,以硅胶和沸石分子筛为吸附剂,计算并讨论循环的热力性能,结果表明:虽然基本吸附式循环的性能比和效率最大可较常规蒸发式海水淡化系统高约30%,但考虑传热温差、吸附床金属热容等实际因素后其性能并无优势,如能通过有效途径提高吸附床间的回热率,则可成倍提高该系统的热力性能。     

热泵系统的(火用)分析

用[火用]分析法对热泵供热循环进行了分析，评价了热泵系统的能质利用和损失状况，指出在环境温度、压缩机效率和两器（蒸发器和冷凝器）换热温差一定时，热泵循环存在一个可使循环[火用]效率达到最大的冷凝温度，可在实际中加以利用。     

一种新型第二类吸收式热泵的原理及性能分析

提出一种包含吸收溶液冷却结晶过程的新型第二类吸收式热泵循环,并对其工作过程及性能特性进行理论分析与实验研究。结果表明,该循环可在吸收器吸收溶液质量分数显著高于发生器吸收溶液质量分数的条件下工作,其热泵温升能力明显优于现有AHT循环。当冷却结晶终温和冷凝器温度为35℃、发生器温度和蒸发器温度为92℃时,其热泵温升理论上可达97℃。     

二类热泵在利用余热供热中的热力分析

对单级二类吸收式热泵进行热力分析,建立了热泵系统各部分质量守恒、能量平衡和火用分析数学模型。根据火用平衡方程计算了各个部分的火用损失和热泵系统的火用效率。分析了溶液换热器稀溶液温差、热源温差、余热源温度和冷却水温度对火用损失、循环倍率和COP等的影响。对热泵系统进行了火用能质量评定,确定了火用能的薄弱环节。     

高温热泵及热泵蒸汽机的研究进展

本文从新型工质的研发和系统效率的提高两方面综述了高温蒸汽压缩式热泵的研究现状,对于高温吸收式热泵,则从新型循环设计、系统控制与仿真、参数优化、提高换热效率等方面做了综述。文章最后介绍了国内外最新研制的两种热泵蒸汽机的运行原理和结构特点,并根据热泵蒸汽机组的运行要求,提出了今后的研究方向和要解决的主要技术问题。     

单双效结合运行的溴化锂第一类吸收式热泵

在传统的单效和双效溴化锂第一类吸收式热泵的基础上,开发单双效结合运行的溴化锂第一类吸收式热泵机组。当用户需求热水温度较低时,机组以双效模式运行;反之,机组则以单效模式运行。克服了溴化锂第一类吸收式热泵供热系统中机组模式单一化、运行效率低的缺点,实现了一台机组两种模式运行的方案,提高了设备和资源的利用率,具有良好的节能效益和经济效益。     

Mass and energy storage analysis of an absorption heat pump with simulated time dependent generator heat input

This communication presents an assessment of the feasibility of energy storage via refrigerant mass storage within an absorption cycle heat pump with simulated time dependent generator heat input. The system consists of storage volumes with the condenser and absorber of the conventional absorption cycle heat pump to store liquid refrigerant, weak and strong solutions during the generation period, which are required for the heat pump operation during the generation off period. A time dependent mass and energy storage analysis based on mass and energy balance equations for various components of the heat pump system has been carried out to evaluate energy storage concentration and storage efficiency for combined and separate storage schemes for the weak and strong solutions. Two possible performance modes, viz constant pumping ratio or the constant flow of the strong solution from the absorber to the generator have been analysed: the latter is preferable over the former from a practical point of view. Numerical computer simulation has been made for a typical winter day in Melbourne (Australia) with the desired heating load specified. It is found that the concept of refrigerant storage within the absorption cycle heat pump is technically feasible for efficient space heating. The energy storage concentration in the condenser store is slighly higher while that in absorber store is slightly lower for the separate storage mode as compared to the combined storage. However, the combined storage has an advantage of less storage volume and hence is more cost effective than separate storage and the disadvantage of limited system operation due to the decrease of solution concentrations.     

不可逆吸收式热泵循环的基本优化关系及性能分析

在恒温热源内可逆四热源吸收式热泵循环的基础上，建立了线性(牛顿)传热定律下考虑泵热空间到环境热源的热漏、工质的内部耗散以及工质与外部热源间的热阻损失的不可逆吸收式热泵循环模型。导出了总换热面积一定的条件下循环的泵热率和泵热系数的基本优化关系、最大泵热率和相应的泵热系数、最大泵热系数和相应的泵热率、以及循环中最佳工质工作温度和最佳换热面积分配关系；并通过数值算例分析了循环参数对循环最优性能的影响规律。     

An experimental investigation of bubble pump performance for diffusion absorption refrigeration system with organic working fluids

An experimental investigation was undertaken to study the performance of the bubble pump for diffusion absorption refrigeration units. The bubble pump is the motive force of the diffusion absorption cycle and is a critical component of the absorption diffusion refrigeration unit. The purpose of the bubble pump (besides the circulation of the working fluid) is to desorb the solute refrigerant from the solution. Therefore the efficiency of the bubble pump will be set by the amount of the refrigerant desorbed from the solution. The performance of the diffusion absorption cycle depends primarily on the efficiency of the bubble pump. A continuous experimental system was designed, built and successfully operated. The experiments were performed in which some of the parameters affecting the bubble pump performance were changed. During the experimental investigation, photographs were taken showing that the bubble pump operates at slug flow regime with a churn flow regime at the entrance of the bubble pump tube. It was obtained that the performance of the bubble pump depends mainly on the motive head and on the heat input to the bubble pump.     

Evaluation of the performance of an absorption–demixtion heat pump for upgrading thermal waste heat

An absorption/demixtion heat pump is used to overcome the classic heat pump's performance limitation due to the high cost of the amount of energy consumed in the separation process. This heat pump concept uses a partially miscible mixture as working fluid instead a binary miscible mixture. Under low pressure the mixture is a heterogeneous solution of two non-miscible phases in thermodynamic equilibrium but at very different compositions. Then the solution spontaneously splits into two liquid phases without any energy supply. Beyond a critical pressure of dissolution the two earlier non-miscible phases become miscible and then form a homogeneous liquid phase. In these conditions, at high temperature, the more volatile phase is evaporated and its vapor absorbed in the less volatile phase in exactly the same way as in the classical heat pump. The features of this system are presented and a comparison is made against the classic absorption heat pump and the compression heat pump. The different steps of the system are represented by the conventional methods of McCabe and Thiele, and Ponchon–Savarit, to provide a good understanding. We calculated the performance of this system and compared its values against those of the absorption heat pump and the compression heat pump: the COP is respectively 2 and 100 times greater because the separation does not need costly energy. Moreover, the system presents investment cost saving because the separator is a simple decanter.     

A high temperature absorption heat pump as topping process for power generation

With a high temperature absorption heat pump as a topping device to the Rankine-water cycle, the efficiency for power generation may be improved by 40–50% above present values. A possible heat-pump process working with water as absorbent and CaO as absorber is discussed by using diagrams which are suited to study the combination of a heat pump with the Rankine cycle.     

Parametric analysis and yearly performance of a trigeneration system driven by solar‐dish collectors

Solar‐driven polygeneration systems are promising technologies for covering many energy demands with a renewable and sustainable way. The objective of the present work is the investigation of a trigeneration system, which is driven by solar‐dish collectors. The examined trigeneration system includes an organic Rankine cycle (ORC), which operates with toluene, and an absorption heat pump, which operates with LiBr/H₂O. The absorption heat pump is fed with heat by the condenser of the ORC, which operates at medium temperature levels (120°C to 150°C). The absorption heat pump produces both useful heat at 55°C and cooling at 12°C. The ORC produces electricity, and it is fed by the solar dishes. The examined ORC is a regenerative cycle with superheating. The total analysis is performed with a developed model in Engineering Equation Solver (EES). The system is investigated parametrically for different ORC heat‐rejection temperatures, different superheating levels in the turbine inlet, and various solar‐beam irradiation levels. Furthermore, the system is investigated on a yearly basis for the climate conditions of Athens (Greece) and for Belgrade (Serbia). It is found that the yearly system energy and exergy efficiencies are 108.39% and 20.92%, respectively, for Athens, while 111.38% and 21.50%, respectively, for Belgrade. The values over 100% for the energy efficiency are explained by the existence of a heat pump in the examined configuration. For both locations, the payback period is found close to 10 years and the internal rate of return close to 10%. The final results indicate that the examined configuration is a highly efficient and viable system, which operates only with a renewable energy source.