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1.
吸收式热泵多效蒸发海水淡化热力性能研究 总被引：1，自引：0，他引：1
提出了两级吸收式热泵多效蒸发海水淡化工艺流程,并建立了系统的数学模型。计算分析了溴化锂溶液浓度和加热蒸汽温度对系统的造水比、生产单位淡水所需传热面积和吸收式热泵的热力系数的影响。研究结果表明,系统的造水比和吸收式热泵的热力系数随加热蒸汽温度和LiBr浓溶液浓度的降低而增大,生产单位质量淡水所需传热面积随加热蒸汽温度的降低而急剧增加;通过调整溴化锂溶液的浓度,能够实现对不同品质热源的利用;该系统不仅能够保证淡水不被溴化锂污染,而且其造水比明显优于喷射泵多效蒸发系统和多效蒸发系统。 相似文献
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The prototype of combined vapour compression–absorption refrigeration system was set up, where a gas engine drove directly an open screw compressor in a vapour compression refrigeration chiller and waste heat from the gas engine was used to operate absorption refrigeration cycle. The experimental procedure and results showed that the combined refrigeration system was feasible. The cooling capacity of the prototype reached about 589 kW at the Chinese rated conditions of air conditioning (the inlet and outlet temperatures of chilled water are 12 and 7°C, the inlet and outlet temperatures of cooling water are 30 and 35°C, respectively). Primary energy rate (PER) and comparative primary energy saving were used to evaluate energy utilization efficiency of the combined refrigeration system. The calculated results showed that the PER of the prototype was about 1.81 and the prototype saved more than 25% of primary energy compared to a conventional electrically driven vapour compression refrigeration unit. Error analysis showed that the total error of the combined cooling system measurement was about 4.2% in this work. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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In the medical field, refrigeration systems are used to store and transport vaccines, blood, and other medical supplies that require specific temperature ranges to remain effective. As technology continues to advance, the demand for more efficient and sustainable refrigeration systems is also increasing. The freezer compartment is typically designed to maintain a temperature of −18°C to −23°C for storing frozen items. Consequently, this work aims to develop a hybrid refrigeration system that combines a thermoelectric cooler system (TEC) and a vapor compression refrigeration cycle (VCC) system to achieve lower temperatures than conventional refrigerators. Also, the performance of the proposed hybrid refrigeration system is experimentally assessed with various operating conditions, including varying the voltage delivered to the system. The experimental results exhibited that the temperature inside the freezer room reached −33°C, while the cold side temperature is −47°C. Also, the maximum coefficient of performance of the VCC system, TEC, and hybrid system is 2.07, 1.06, and 0.37, respectively, at a DC voltage applied of 6 V. Moreover, the results revealed that the hybrid system combining a TEC and a VCC system can be a valuable technology for specific applications with low temperatures and limited capacity requirements. 相似文献
4.
This paper presents a new design of a prototype refrigeration-cum-hot water heating system for domestic use. The system uses the heat energy rejected from the compressor and condenser of a vapour-compression refrigerator by storing it in a heat sink. This energy is then transferred to mains water entering the hot water cylinder, where the water temperature is boosted by an electric resistance heater to a preset temperature for domestic usage. A prototype system of such a configuration was assembled as an integrated unit with the refrigerator adjacent to the water tank. The system is called the Home Energy Centre (HEC). Power consumption and temperature distribution were measured for standing and draw off tests using the unit as a conventional hot water cylinder, refrigerator or as the combined system. A new parameter, ϕ, is defined to compare the system performance as the HEC prototype against its performance when working only as a refrigerator or a water heater. The system performed better as the prototype than it did as a hot water heater, but needs to be improved further to fully explore its expected potential. © 1998 John Wiley & Sons, Ltd. 相似文献
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Edson Adriano Vendrusculo Guilherme de Castilho Queiroz Gilberto De Martino Jannuzzi Herculano Xavier da Silva Júnior José Antenor Pomilio 《Energy Efficiency》2009,2(3):271-286
The purpose of this paper was to present the results of a life cycle cost analysis concerning the purchase and operation of
a more efficient popular refrigerator model compared with a baseline design in Brazil. The summarized results may be useful
for organizations working to promote sustainable energy development. This paper specifically focuses on refrigerators, since
their energy consumption is predicted to constitute over 30% of the total average domestic electricity bill in Brazilian households.
If all new Brazilian refrigerators had an energy efficiency at the level consistent with the least life cycle cost of ownership,
it would result in an annual savings of 2.8 billion dollars (US$) in electricity bills, 45 TWh of electricity demand, and
18 Mt of CO2 emissions, with a respective payback period of 7 years which is less than half the average estimated lifetime of a refrigerator.
The analysis was conducted following the guidelines of similar analyses available from the US Department of Energy and the
Collaborative Labeling and Appliance Standards Program.
相似文献
| Edson Adriano VendrusculoEmail: |
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Due to the rapid economic development, living standards in China are improving fast. Chinese families are having more household electrical appliances, among which refrigerators are indispensable. Energy consumption of refrigerators is huge in China and causes environmental concerns. China has issued the national energy efficiency standards of household refrigerators, GB12021.2-2003 and GB12021.2-2008 to promote high-efficiency refrigerator production and use. This study evaluated the impacts of the standards on the environment, manufacturers and consumers over a long-term period of 2003–2023. It first evaluated the potential electricity conservation and GHG emission reduction resulting from energy efficiency improvements driven by the standards. Next, manufacturers’ technological and economic concerns about complying with the standards were discussed. Some efficiency improving design options were considered and the resulting increases in manufacturing cost and retail price were estimated. The return of consumers from invest in efficiency was analyzed based on lifecycle cost saving of the improved models. The economical viability of the standards was then evaluated by national consumer costs and benefits. Results showed that the considered efficiency standards will potentially save a cumulative total of 588–1180 TWh electricity, and reduce emission of 629–1260 million tons of CO2, 4.00–8.04 million tons of SOx and 2.37–4.76 million tons of NOx by 2023, depending on sale share of models by efficiency. In a more environmentally optimal case (75% sale share of high-efficiency models), the national consumer benefits are 121 billion RMB (discounted), with the benefit/cost ratio of consumer’s expenditure being 1.45:1. However, the preference to high-efficiency models is substantial influenced by consumer’s expectation on return from the additional cost on efficiency. 相似文献
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The present work focused on the comparative analysis of organic Rankine cycle (ORC) operated with nanoparticles. The effect of CuO and Al2O 3 nanoparticles synthesized with water and circulated within heat exchangers are examined. Thermal efficiency and levelized energy cost (LEC) of the nanofluid based ORC are evaluated simultaneously in the present work. The optimization problem of ORC is formed and solved using heat transfer search algorithm. Operating parameters of the nanofluid based ORC such as pinch point temperature difference of heat exchangers, evaporation pressure, the mass flow rate of refrigerant, and concentration of nanoparticles are investigated in the optimization study. Further, the effect of turbine ratio, heat source temperature, and mass flow rate of heat source fluid on CuO and Al 2O 3 based ORC is explored and discussed. It was observed that a total variation of 35.2% was obtained at the cost of 3.5% variation in LEC between extreme design points. The maximum thermal efficiency of 19.3% and 19.32% can be obtained with CuO and Al 2O 3 with 2.616 and 2.62 $/kWh, respectively. Comparative results reveal that CuO based ORC shows dominance in terms of economic performance over Al 2O 3 based ORC for any given value of the thermal efficiency. 相似文献
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Thermoelectric generator is among the earliest initiated electricity‐harvesting methods. It is a very potential power harvester that can convert wasteful thermal energy into electricity. However, it often suffers from low energy conversion rate due to its inconsistent heat source, inefficient thermoelectric material (or thermoelement) performance, and incompetent structural issues. Progressively for the first time, detailed methodological surveys and analyses are made for bulk, thick, and thin films in this review. This is in order to accommodate better insights and comprehensions on the emerging trends and progresses of thermoelectric generators from 1989 to 2017. The research interests in thermoelectric generators have started back in 1989, and have continuously experienced emerging progresses in the number of studies over the last years. The methodological reviews and analyses of thermoelectric generator showed that almost 46.6% of bulk and 46.1% of thick and thin film research works, respectively, are actively progressed in 2014 to 2017. Nearly 86.2% of bulk and 44.1% of thick and thin film thermoelectric generators are realizing in between 0.001 and 4 μW cm?2 K?2, while 43.1% of thick and thin films are earning among 10?6 to 0.001 μW cm?2 K?2. The highest achievement made until now is 2.5 W cm?2 at a temperature difference of 140 K and thermoelectric efficiency factor of 127.55 μW cm?2 K?2. This achievement remarked positive elevation for the field and interest in thermoelectric power generation. Consecutively, the research trends of fundamental devices' structure, thermoelement, fabrication, substrate, and heat source characteristics are analyzed too, along with the desired improvement highlights for the applications of thermoelectric generators. 相似文献
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通过在光伏组件的背面连接了一个热电转换模块,形成一个光伏一热电混合模块,从而将光伏组件工作过程中产生的废热转换成电能的同时又降低了光伏组件的温度,进而提高了光电转换效率。将光伏一热电模块与百叶有效结合,从而实现了室内采光、通风及节约空间等多种功能。同时,为了提高光伏组件的入射太阳辐射,引入了可调节的抛物型双面聚焦板,减少了太阳能电池板的面积,从而减少了太阳能发电的成本。 相似文献
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《Energy Policy》2013
In a post-carbon energy economy, just as during the Age of Fossil Fuel, the locations where men take control of energy resources (e.g., the coal-pit, the mill wheel, the terminals of a concentrating solar power generator) will often be far removed from the locations where they wish to expend those resources. Therefore, the captured energy resource, once isolated, must somehow be translated from its point of origin to its point of use; and in doing so, its owner must expend energy. In this paper it is argued that, in a sustainably fueled future: (i) renewable energy in its initially transportable form will be overwhelmingly electrical; (ii) energy frugality will dictate long-distance transport of energy as electricity; (iii) intermediate-term (less than a fortnight) storage of energy will be via compressed air energy storage or pumped hydro- or electrochemical batteries, which can not be comparatively evaluated without extensive expensive development and demonstration; and (iv) massive conversion of electrical energy into synthetic fuels will be restricted to selected transportation applications. 相似文献
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采用模拟的方法,对朗肯循环、卡琳娜循环和上原循环建模,在不同热源温度环境下,分析不同循环流程热效率η和平准化度电成本CLCOE的差异;同时,通过对循环蒸发温度和透平入口压力进行分析,探究其在不同循环流程中对热经济性能的影响。研究结果表明,卡琳娜循环在各热源温度下均有较高的热效率,但经济指标表现不佳;低温热源环境,纯氨工质朗肯循环在同等条件下CLCOE最低,在设计时,朗肯循环应选用饱和蒸汽状态,尽可能增加透平入口压力,减小蒸发过热度;高温热源环境,上原循环CLCOE最低,卡琳娜循环和上原循环CLCOE极小值与热效率极大值对应的透平入口压力存在偏差,按最小CLCOE标准可获得更高的发电量和更低的设备成本。因此,在流程设计时,需考虑不同循环在各热源环境中的热经济性能。 相似文献
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对分布式能源系统的冷热电三联供系统进行了热力学分析,比较了原动机（燃气轮机与燃气内燃机）和制冷机组（单效与双效制冷溴化锂机组）的优缺点及其在三联供系统中的应用特点,揭示了微型燃气原动机三联供系统的设计优化原则。 相似文献
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热管废热溴化锂制冷机的优化设计 总被引：1，自引：0，他引：1
介绍了烟气驱动的热管废热溴化锂制冷机的优化设计，建立了热管废热溴化锂制冷机的优化设计计算模型，并编写了优化设计程序，得出了整个装置的结构参数。 相似文献
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We report a study of using the waste heat from a window-type air-conditioner to heat water for domestic use. Results show 401 of water can be heated to about 90°C in about and the room cools faster when the water heating system is introduced than in the case when it functions normally. A qualitative discussion of the efficiency of the water heating system is presented. This elimination of the traditional unnecessary waste of energy can be a significant saving of energy in Malaysia where window units and traditional (electrically heated) hot water tanks are common in typical housing estates in Malaysia. 相似文献
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以能源平均成本和动态投资回收期为经济性指标,对采用平板集热器、真空管集热器、复合抛物面集热器和槽式集热器驱动的太阳能单效溴化锂吸收式制冷系统进行了对比分析,同时以?效率和动态投资回收期为目标对优选的太阳能制冷系统进行了多目标优化。结果表明：采用真空管集热器的太阳能制冷系统的能源平均成本最低及动态投资回收期最短;发生器热水进口温度存在最优值使得系统?效率最高,能源平均成本最低;增加系统装机容量可有效降低系统的能源平均成本并且缩短投资回收期;太阳辐照强度越大,太阳能制冷系统的能源平均成本越低及投资回收期越短。此外,多目标优化结果表明发生器热水进口温度存在最优值可使得综合目标函数取得最小值。 相似文献
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Kotaro Tanaka 《亚洲传热研究》2001,30(3):234-244
The alkali metal thermal to electric converter (AMTEC) system which utilizes the sodium ion conductivity of a beta″‐alumina solid electrolyte (BASE) is expected to have high conversion efficiency above 30% including practical heat losses. However, the achieved experimental efficiencies have been around 15%. In this paper, current–voltage characteristics and heat and mass transfer processes on a single cell have been examined experimentally and thermal electrode conversion efficiency has been discussed. Measured electrode conversion efficiency without thermal losses showed that it was about 40% at a power density of 0.3 W/cm2. A theoretical analysis on the thermal losses has also been conducted and these losses are estimated to be 0.3 W/cm2 in a practical tube type cell, so that an actual cell system efficiency of 30% is expected. © 2001 Scripta Technica, Heat Trans Asian Res, 30(3): 234–244, 2001 相似文献
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The current Spanish energy model has become obsolete for social, economic and environmental reasons. This conditions the economic and social model of the country. To change the model, a transition period is required and the identification of energies available in the vicinity, citizen commitment, the mobilisation of technological and economic resources, a model of efficiency, generation and distribution. In this new model, compliance with environmental commitments, the generation of economic activity and the guarantee that the transition will not involve uncertainty in terms of availability and security of supply, must be unquestionable commitments. To this end, the possibilities of implementing a sustainable energy model, of proximity, that allows maintaining an industrial economic structure, has been studied in a region of the Basque Autonomous Community (Spain). This article presents the different phases of the study, the methodology used, conclusions and the bases for a sustainable model. 相似文献