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1.
针对传统蒸气压缩制冷系统和太阳能吸收制冷系统的诸多问题,本文提出一种新型的可利用太阳能的蒸气压缩式制冷系统,该系统是由电驱动的蒸气压缩式制冷循环与太阳能驱动吸收式制冷循环组成的复合式系统,分析系统工作原理与特点,并通过理论计算分析24h时间段太阳辐射强度对组成新系统的吸收制冷循环的循环特性(COP)和新系统的循环特性(COP)的影响。  相似文献   

2.
耦合吸附吸收制冷系统的实现及其特性   总被引:1,自引:0,他引:1  
针对现有吸附制冷系统采用单组分工质作为吸附质导致系统的压力偏高或偏低,且吸附、吸收式制冷效率较低的状况,根据吸收式制冷和吸附式制冷的工作原理及特点,提出了耦合吸附吸收制冷的新技术;同时分别采用13X分子筛、氯化钙和硅胶作为吸附剂,双组分工质氨一水为制冷工质,在不同脱附温度和氨水含量下进行研究.实验结果表明,与使用单组分工质一水比较,系统性能系数可提高2倍以上;由于将脱附蒸汽的冷凝过程设计成吸收过程,因而使系统在常压下运行成为可能.该研究结果为高效率低成本制冷机的研制提供了理论基础.  相似文献   

3.
提出了用气-液喷射器代替机械泵,有效回收低品位余热能源的新型双喷射式制冷系统.该制冷循环本身不需要消耗电能.研究了气-液喷射器的运行特性和喷射系数与工作参数的关系,发现在一定范围内系统效率随工作压力提高而提高,然后下降.分析了双喷射式制冷系统COP与发生器温度、冷凝器温度的关系,模拟了不同余热温度条件下双喷射式制冷系统的运行性能,结果表明制冷剂R123制冷性能优于R134a.系统COP可达0.3.  相似文献   

4.
围绕以LiBr/H2O为工质对的单级太阳能吸收式制冷循环因对太阳能集热温度要求高而难以实现应用的问题,提出了CaCl2-LiBr(1.35:1)/H2O(CaCl2与LiBr的质量比为1.35:1)新型工质对,系统地测定了其结晶温度、饱和蒸气压、密度和黏度,并与LiBr/H2 O进行了比较.结果表明,采用CaCl2-LiBr(1.35:1)/H2 O作为太阳能单级吸收式制冷循环的工质对,在同一制冷工况条件下,其发生温度,即太阳能集热温度比采用LiBr/H2 O的情况低6.2℃.另外,采用浸泡法测试了碳钢、316L不锈钢和紫铜在CaCl2-LiBr(1.35:1)/H2 O中的腐蚀速率,结果表明316L不锈钢和紫铜的腐蚀性非常小,可满足实际工程应用的要求.  相似文献   

5.
This paper presents the importance and the cycle choice for long-distance transportation of low-grade thermal energy, and the thermodynamic and hydrodynamic feasibility of single-effect ammonia-water absorption system for heat or cold transportation over long distance are also involved. A model of a long-distance thermal energy transportation system is built and analyzed, which shows satisfactory and attractive results. When a steam heat source at 120℃ is available, the user site can get hot water output at about 55℃ with the thermal COP of about 0.6 and the electric COP of about 100 in winter, and cold water output at about 10℃ with the thermal COP of about 0.5 and the electric COP of 50 in summer. A small-size prototype is built to verify the performance analysis. Basically the experimental data show good accordance with the analysis results. The ammonia-water absorption system is a potential pro-spective solution for the heat or cold transportation over long distance.  相似文献   

6.
为研究天然气冷热电三联供分布式能源(combined cooling heating and power,CCHP)系统的能量利用特性,以某冷热电三联供能源站作为研究对象,利用EBSILON软件分别建立内燃机组、烟气-热水型溴化锂吸收式冷水机组、换热器组件等模型,分析了烟气-热水型溴化锂吸收式冷水机组在不同烟气与缸套水热源驱动下的制冷系数(coefficient of refrigeration,COP)特性,内燃机组不同负荷率下系统的综合供能特性.研究结果表明,CCHP采用单一热源制冷时,烟气热水型溴化锂吸收式冷水机组以烟气作为驱动热源可获得较高的COP,而以缸套水作为驱动热源时COP较低;在同时具备冷热负荷情况下,高温烟气更适合作为制冷热源,而高温缸套水更适合充当制热热源;采用双热源驱动制冷与单一热源相比,具有更高的综合能源利用效率,在内燃机75%负荷率、WY1工况下,COP与综合能源效率达到最大值1.28与92.0%;而在50%负荷率时采用缸套水作为单一热源驱动制冷机时,COP与综合能源利用效率达到最低值,分别为0.74与76.1%.模型分析得出的CCHP系统综合供能特性,在一定程度上可有效指导冷热电三联供能源站的高效运行.  相似文献   

7.
一种新型太阳能制冷循环的控制系统研究   总被引:2,自引:0,他引:2  
提出了一种新型太阳能混合吸收式蓄能循环的控制系统.混合式蓄能循环的控制系统采用n阶等容惯性环节来描述其动态特性,在比例积分调节方式下,从个别环节控制入手,进而达到综合能量控制.并利用C 语言编制程序对系统的运行进行仿真,达到了运行的最优化和蓄能节能的目的.  相似文献   

8.
提出一种太阳能驱动的小型风冷氨水吸收式制冷循环系统,该系统有效回收精馏热及吸收热,降低发生温度,实现机组风冷化以及对太阳能的有效利用,增加系统能效比。在建立组成系统各部件热力学数学模型基础上,对循环特性进行计算,得出在热源温度、蒸发温度、冷凝温度等参数变化时,性能因数的变化规律,为系统优化设计提供理论基础。  相似文献   

9.
R290/CO2自然工质低温复叠式制冷循环理论分析   总被引:7,自引:0,他引:7  
介绍了低温环境下采用自然工质R290和CO2的复叠式制冷循环。分析了R290和CO2的物性特征,通过对R290/CO2复叠式制冷循环的理论分析,在一定的蒸发温度和冷凝蒸发器传热温差下,计算出循环存在最优的低温循环冷凝温度和最优质量流量比;为提高循环效率和保证循环的安全运行。应尽可能地升高蒸发温度、降低冷凝温度和减少冷凝蒸发器的传热温差,可以看出R290/CO2的复叠式制冷循环在低温制冷条件下有很好的发展前景.  相似文献   

10.
固体吸附式制冷技术的概况及进展   总被引:13,自引:0,他引:13  
吸附式制冷作为能有效利用太阳能和工业废热等低品位能源,而又没有环境破坏性的新型制冷技术越来越多地受到重视.近年来,国内外众多学者从吸附剂-制冷剂工质对的性能、吸附式制冷循环的特性、吸附床的传热传质等诸多方面,在所建立的一些样机上对吸附式制冷系统的性能作了大量的研究工作.但目前对一些新型循环的可实现性和系统性能及其稳定性的提高方面还需要作大量的研究,以促进吸附式制冷技术走向实际应用市场.  相似文献   

11.
Membrane distillation technology is a new type of efficient separation technology that combines traditional distillation technology and membrane separation technology. In the study, applications of membrane distillation technology in thermal engineering and refrigerating engineering with typical energy transformation process were presented. Desorption and regeneration process of saline solution by vacuum membrane distillation was proposed on the basis of the concentration and separation properties of membrane distillation. Membrane distillation technology could be used in lithium bromide absorption refrigeration system, energy storage system, and the regeneration process of liquid desiccant solution in temperature-humidity independent control air-conditioning system. The aim of the applications was to use the low-grade energy such as waste heat, solar energy and geothermal energy adequately and to improve the available temperature difference of heat source. According to latent heat transfer and thermal conduction across the membrane in direct contact membrane distillation process, a novel membrane heat exchanger with both heat transfer and mass transfer processes was proposed. The heat exchanger could be used as the solution heat exchanger of lithium bromide absorption refrigeration system and as the special heat exchanger that recovered heat and pure water simultaneously. Some feasible process flows about the applications of membrane distillation technology to energy transformation process were listed and analyzed. Finally, future research emphases were indicated.  相似文献   

12.
为了使R744在复叠式制冷系统中运行的最低温度突破三相点的限制,用R744与自然工质(如R170或R1150)混合组成二元混合物,使其突破R744的三相点温度,完全使用自然工质混合物替代R13,在复叠式制冷系统的低温环路中运行.通过建立固液平衡和气液平衡的模型,得到保证R744在200K不结晶的摩尔分数,并针对固定组分的二元混合物进行循环性能计算.计算结果表明,R744/R170的一种混合物在相同的冷凝和蒸发温度下与R13相比,压缩比相同,压力曲线非常接近,单位容积制冷量、单位质量制冷量和制冷系数相差不大,具有与R13相近的循环性能.质量比为2:8的R744/R170混合物是R13的理想的自然工质替代物.  相似文献   

13.
通过建立R290/CO2复叠式制冷系统实验台,对R290/CO2蒸气压缩复叠式制冷循环进行了实验研究,结果表明,CO2循环在较低温度下运行,黏性对CO2经过压缩机的性能影响较大,对流过管路的影响较小,CO2压缩机的压力比高于11290压缩机的压力比,但由于CO2压缩机由吸入的较低温度的工质冷却,CO2压缩机的排气温度低于11290压缩机的排气温度;CO2循环的能量损失较大,使得CO2循环的性能系数低于11290循环的性能系数.在CO2循环中可利用无吸排气阀的回转式压缩机,用膨胀机代替节流阀,以提高R290/CO2复叠式制冷循环的性能系数.  相似文献   

14.
通过对双温冰箱压缩/喷射式混合制冷循环系统的分析阐明了混合循环的节能原理,同时推导了混合制冷循环的理想制冷系数.理论计算表明混合制冷循环系统的效率比简单制冷循环的高.  相似文献   

15.
Thermochemical sorption refrigeration powered by low-grade thermal energy is one of the energy-saving and environment friendly green refrigeration technologies. The operation principle of sorption refrigeration system is based on the thermal effects of reversible physicochemical reaction processes between sorbents and refrigerants. This paper presents the developing study on the different thermochemical sorption refrigeration cycles, and some representative high-efficient thermochemical sorption refrigeration cycles were evaluated and analyzed based on the conventional single-effect sorption cycle. These advanced sorption refrigeration cycles mainly include the heat and mass recovery sorption cycle, double-effect sorption cycle, multi-effect sorption cycle, combined double-way sorption cycle, and double-effect and double-way sorption cycle with internal heat recovery. Moreover, the developing tendency of the thermochemical sorption refrigeration is also predicted in this paper. Supported by the Key Project of the Natural Science Foundation of China (Grant No. 50736004)  相似文献   

16.
一种新型制冷机能量调节的控制算法   总被引:2,自引:0,他引:2  
研究新型混合吸收式制冷循环的能量调节的自动控制问题.采用动态矩阵预测控制算法设计多变量动态矩阵控制器,对新型混合吸收式制冷循环的能量进行自动调节,同时利用软件Matlab/Simulink对其进行仿真,结果表明该算法能有效地改善控制器的动态特性,显著提高制冷机的抗干扰性,表现出了较好的自适应能力.  相似文献   

17.
Different from the traditional hydraulic oil cooling method,a new type of constant temperature oil tank cooling system based on semiconductor refrigeration technology is designed. This paper studies the principle of semiconductor refrigeration and establishes a heat transfer model. Semiconductor cooler on piping refrigeration is simulated,and influence of the parameters on the outlet temperature,such as pipe pressure difference of inlet and outlet,pipe length,pipe radius,are gotten,and then hydraulic tank semiconductor refrigeration system is proposed. The semiconductor refrigeration system can control temperature at 37 ± 1°C.  相似文献   

18.
Adsorption refrigeration systems have the advan- tages of environment benign, zero ozone depletion po- tential (ODP) as well as zero global warming potential (GWP) due to the use of natural refrigerants such as ammonia, water, methanol, etc. Adsorption re…  相似文献   

19.
在分析基本吸附制冷循环的基础上,建立了基本吸附制冷循环热力过程中的各个热量的计算表达式.针对氯化钙氨吸附制冷实验系统的两种典型工况(制冷工况和空调工况),就解吸终了温度和吸附终了温度对制冷性能的影响进行了热力计算和分析,明确了空调工况下制冷系统性能更好的原因,并对计算结果从热力学理论角度进行了分析验证.  相似文献   

20.
The importance of organic compounds as significant constituents of atmospheric aerosols, and cloud condensation nuclei (CCN), as well as players influencing the tropospheric oxidation and atmospheric energy budget, have been increasingly recognized. Low molecular weight dicarboxylic acids (LMW-DCAs) are significant identified portions of atmospheric condensed matter including aerosols, fog and clouds. Besides the photochemical transformation of DCA, the implication of organic matter in ice nucleation processes has been considered. In this study, we investigated the freezing temperature of pure and mixed (C2-C6) DCA solutions in ultra-pure water and tap water solution droplets using a freezing nucleus counter at different pH, and in different water ionic conditions. The mean freezing temperature of different mixture of LMW-DCA in ultra-pure and tap water solution droplets ranged from -24.1±2.8 to -21.3±3.9℃ and -10.2±2.2 to -9.5±2.2℃, respectively. The mean freezing temperature of the control (ultra-pure and tap) water droplets (-22.6±3.5℃, 11.2±2.4℃) was also measured. The results, and their implications in atmospheric chemistry and physics of the atmosphere will be discussed.  相似文献   

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