Combined cooling, heating and power: A review

Combined cooling, heating and power (CCHP) systems, including various technologies, provide an alternative for the world to meet and solve energy-related problems, such as energy shortages, energy supply security, emission control, the economy and conservation of energy, etc. In the first part of this paper, the definition and benefits of CCHP systems are clarified; then the characteristics of CCHP technologies—especially technical performances—are presented, as well as the status of utilization and developments. In the third part, diverse CCHP configurations of existing technologies are presented, particularly four typical systems of various size ranges. The worldwide status quo of CCHP development is briefly introduced by dividing the world into four main sections: the US, Europe, Asia and the Pacific and rest of the world. It is concluded that, within decades, promising CCHP technologies can flourish with the cooperative efforts of governments, energy-related enterprises and professional associations.     

Prospects for solar cooling – An economic and environmental assessment

Producing refrigeration and/or air conditioning from solar energy remains an inviting prospect, given that a typical building’s cooling load peaks within 2 or 3 h of the time of maximum solar irradiation. The attractiveness of “free” cooling obtained from the sun has spawned a wealth of research over the last several decades, as summarized in a number of review articles. Obstacles—especially high initial costs—remain to the widespread commercialization of solar cooling technologies. It is not clear at the present time if thermally driven systems will prove to be more competitive than electrically driven systems. We therefore describe a technical and economic comparison of existing solar cooling approaches, including both thermally and electrically driven. We compare the initial costs of each technology, including projections about future costs of solar electric and solar thermal systems. Additionally we include estimates of the environmental impacts of the key components in each solar cooling system presented. One measure of particular importance for social acceptance of solar cooling technologies is the required “footprint,” or collector area, necessary for a given cooling capacity. We conclude with recommendations for future research and development to stimulate broader acceptance of solar cooling. The projections made show that solar electric cooling will require the lowest capital investment in 2030 due to the high COPs of vapor compression refrigeration and strong cost reduction targets for PV technology.     

Solar refrigeration and cooling

In this paper a review of solar cooling and refrigeration technologies is presented. A discussion on the main reasons why these technologies are not presently economically feasible is carried out. and two installations in Mexico are analysed.     

A comprehensive review of solar thermoelectric cooling systems

The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. This paper provides an overview of solar thermoelectric (TE) cooling systems. Thus, this review presents the details referring to TE cooling parameters and formulations of the performance indicators and focuses on the development of TE cooling systems in recent decade with particular attention on advances in materials and modeling and design approaches. Additionally, the TE cooling applications have been also reviewed in aspects of electronic cooling, domestic refrigeration, air conditioning, and power generation. Finally, the possibility of solar TE cooling technologies application in “nearly zero” energy buildings is briefly discussed, and some future research directions are included. This research shows that TE cooling systems have advantages over conventional cooling devices, including compact in size, light in weight, high reliability, no mechanical moving parts, no working fluid, being powered by direct current, and easily switching between cooling and heating modes.     

Combined cooling heat and power in supermarkets

With recent initiatives from the UK government on reduced energy use, energy efficient systems such as combined heat and power (CHP) have been considered for new applications, including supermarkets. In these commercial buildings, the seasonal demand for heat results in underutilisation of the CHP equipment, limiting the primary energy savings that may be achieved. To increase the utilisation time, it has been proposed that heat generated by the CHP unit could be used to power an absorption refrigeration system providing cooling for the refrigerated cabinets. The application of an integrated CHP/absorption scheme or combined cooling heat and power (CCHP) in the supermarket is the subject of this paper.The paper initially describes the cooling/heating/power requirements of a typical supermarket and then reviews a number of CCHP options involving the use of different cooling and engine technologies. The investigation calculates and compares the energy savings/capital costs of the different options against typical conventional supermarket technology.     

冷热电联产系统的发展及前景

1前言能源的价格、电网的稳定性、能量的品质、空气的品质以及全球气候的改变,是21世纪我们面临的严重问题。随着经济和社会的发展,这些问题将变得更加尖锐。在传统的利用燃料产生电力的过程中,将近三分之二的输入能量没有有效利用就被释放到环境中,能量损失十分严重。利用总能     

Selection of sustainable prime mover for combined cooling,heat, and power technologies under uncertainties: An interval multicriteria decision‐making approach

This study aims at developing an interval multicriteria decision‐making method for helping the stakeholders to select the most sustainable prime mover for combined cooling, heat, and power (CCHP) technologies under uncertainties for promoting the sustainable development of CCHP system. The “interval best‐worst method,” which can address the vagueness and ambiguity existing in the judgments of the decision‐makers, has been developed for determining the weights of the evaluation criteria. The interval VIKOR method which can rank the alternatives with imprecise data has been used to prioritize the alternative prime movers for CCHP technologies. Four alternative prime movers including internal combustion engine, gas turbines, microturbines, and fuel cells were studied by the developed method, and the sustainability order of the 4 prime movers from the most sustainable to the least is fuel cells, microturbines, gas turbines, and internal combustion engine. Sensitivity analysis was also carried out to investigate the influences of the weights of the sustainability criteria on the sustainability ranking of the alternative prime movers, and the results reveal that the sustainability rankings are very sensitive to the weights of sustainability criteria.     

Review of solar sorption refrigeration technologies: Development and applications

In this paper, a review of the research state of art of the solar sorption (absorption and adsorption) refrigeration technologies is presented. After an introduction of basic principles, the development history and recent progress in solar sorption refrigeration technologies are reported. The application areas of these technologies are categorized by cooling temperature demand. It shows that solar-powered sorption refrigeration technologies are attractive alternatives that not only can serve the needs for air-conditioning, refrigeration, ice making and congelation purposes, but also can meet demand for energy conservation and environment protection. However, a lot of research work still needs to be done for large-scale applications in industry and for the replacement of conventional refrigeration machines.     

A high proportion of new energy access–combined cooling,heating, and power system planning method

Distributed generation (DG) technologies are environmentally friendly and have low operating costs, and thus, distributed generators are widely used for the energy supplies of buildings. Solar energy used for on‐demand heating of buildings is also a mature technology that is environmentally friendly and inexpensive and has a short recycling life cycle. This paper proposes a high proportion of new energy access–combined cooling, heating, and power (HPNE‐CCHP) system composed of a distributed generator and solar energy heat pump system. To obtain the optimum capacity of the HPNE‐CCHP system, nondominated sorting genetic algorithm‐II (NSGA‐II) was used to optimize the system by considering the life cycle cost (LCC) and life cycle pollutant emissions (LCPE) as the objective functions. A mixed integer economic scheduling model (MIESM) was proposed to make the HPNE‐CCHP system operate more economically. Finally, an HPNE‐CCHP system was constructed for a building in Northern China. The simulation results show that an HPNE‐CCHP system with a moderate proportion of new energy is more economical and environmentally friendly than a traditional CCHP system. Building occupants, depending on their desired spending, can select the best capacity configuration on the Pareto frontier. Although pollutant emissions will be reduced as the proportion of new energy increases, this type of configuration is expensive.     

Performance comparison of combined cooling heating and power system in different operation modes

Operation mode of combined cooling heating and power (CCHP) system determines its energetic and environmental performances. This paper analyzes the energy flows of CCHP system and separated production (SP) system. The fuel energy consumptions of CCHP system following electrical demand management (EDM) and thermal demand management (TDM) are deduced respectively. Three indicators: primary energy saving, exergy efficiency and CO₂ emission reduction, are employed to evaluate the performances of CCHP system for a commercial building in Beijing, China. The feasibility analysis shows that the performance of CCHP system is strictly dependent upon building energy demands. The selection of CCHP operation modes is systemically based on building loads, CCHP system and local SP system. The calculation results conclude that CCHP system in winter under EDM achieves more benefits than in summer. The sensitivity discussion indicates that the coefficient of performance for cooling and the efficiency of electricity generation are the most sensitive variables to the energetic and environmental performances of CCHP system.     

Multiple effects of energy storage units on combined cooling,heating and power (CCHP) systems

Albeit numerous studies discussing manifold issues of combined cooling, heating and power (CCHP) systems, there is still lack of theoretical studies indicating to what extent the energy mismatch and the deviating working conditions affect the CCHP performance, absence of reports systematically summarizing the multiple effects of energy saving units (ESUs), and deficiency of research quantifying the benefits from ESUs to energy savings. The shortage of such studies will confuse some CCHP designers when a CCHP system is designed. Therefore, in this research, theoretical discussions have been undertaken about the energy mismatch issue between CCHP systems and their users as well as the multiple effects of ESUs on CCHP systems. An improved calculational method of energy storage rate (ESR) has been adopted to evaluate the energy savings performance of CCHP systems. Two general heat‐to‐electricity ratios (R_user for CCHP users and R_CCHP for CCHP systems) have been used to quantify the energy mismatch between CCHP systems and their users. In the regime of ‘priority of providing cooling’, the ESR reaches its maximum when R_user is equal to R_CCHP. Otherwise, the ESR tends to decrease rapidly, especially when the electrical demand must be supplemented from the grid. Furthermore, when the CCHP system produces more electricity than required, the payment mode of extra electricity from the CCHP system will significantly affect the ESR. Therefore, it is imperative to reach an international consensus regarding the dispose of extra CCHP products. The theoretical analyses also corroborate the advantages of incorporating an ESU into a CCHP system. The ESU enables the CCHP system components to operate at their optimal working conditions. Meanwhile, the power generation unit and the absorption refrigerator capacities can then be reduced. Moreover, the ESU also promotes the productivity of electricity and ensures an undiminished ESR regardless of what extra electricity payment mode is adopted. Copyright © 2016 John Wiley & Sons, Ltd.     

Thermally driven cooling coupled with municipal solid waste-fired power plant: Application of combined heat,cooling and power in tropical urban areas

Energy recovery from flue gases in thermal treatment plants is an integral part of municipal solid waste (MSW) management for many industrialized nations. Often cogeneration can be employed for both enhancing the plant profitability and increasing the overall energy yield. However, it is normally difficult to justify traditional cogeneration in tropical locations since there is little need for the heat produced. The main objective of this article is to investigate the opportunities and potentials for various types of absorption technologies driven by MSW power plants for providing both electricity and cooling. Results show that cogeneration coupling with thermally driven cooling is sustainably and economically attractive for both electricity and cooling production. The thermally driven cooling provides significant potential to replace electrically driven cooling: such systems are capable of providing cooling output and simultaneously increasing electricity yield (41%). The systems are also capable of reducing the fuel consumption per unit of cooling in comparison with conventional cooling technology: a reduction of more than 1 MW_fuel/MW_cooling can be met in a small unit. MSW power plant coupled with thermally driven cooling can further reduce CO₂ emissions per unit of cooling of around 60% as compared to conventional compression chiller and has short payback period (less than 5 years).     

Analysis of combined cooling,heating, and power systems based on source primary energy consumption

Combined cooling, heating, and power (CCHP) is a cogeneration technology that integrates an absorption chiller to produce cooling, which is sometimes referred to as trigeneration. For building applications, CCHP systems have the advantage to maintain high overall energy efficiency throughout the year. Design and operation of CCHP systems must consider the type and quality of the energy being consumed. Type and magnitude of the on-site energy consumed by a building having separated heating and cooling systems is different than a building having CCHP. Therefore, building energy consumption must be compared using the same reference which is usually the primary energy measured at the source. Site-to-source energy conversion factors can be used to estimate the equivalent source energy from site energy consumption. However, building energy consumption depends on multiple parameters. In this study, mathematical relations are derived to define conditions a CCHP system should operate in order to guarantee primary energy savings.     

Review on solar-driven ejector refrigeration technologies

The objective of this paper is to provide a literature review on solar-driven ejector refrigeration systems and to give useful guidelines regarding background and operating principles of ejector. The development history and recent progress in solar-driven ejector refrigeration systems are reported and categorized. It shows that solar-driven ejector refrigeration technologies are not only can serve the needs for cooling requirements such as air-conditioning and ice-making and medical or food preservation in remote areas, but also can meet demand for energy conservation and environment protection. For these reasons, the research activities in this sector are still increasing to solve the crucial points that make these systems not yet ready to compete with the well-known vapour compression system. However, a lot of research work still needs to be done for large-scale applications in industry and for the replacement of conventional refrigeration machines.     

Performance characteristics and modelling of a micro gas turbine for their integration with thermally activated cooling technologies

We have developed a simple model of a micro gas turbine system operating at high ambient temperatures and characterized its performance with a view to integrating this system with thermally activated cooling technologies. To develop and validate this model, we used experimental data from the micro gas turbine test facility of the CREVER research centre. The microturbine components were modelled and the thermodynamic properties of air and combustion gases were estimated using a commercial process simulator. Important information such as net output power, microturbine fuel consumption and exhaust gas mass flow rate can be obtained with the empirical correlations we have developed in this study. This information can be useful for design exhaust gas fired absorption chillers. Copyright © 2006 John Wiley & Sons, Ltd.     

A new combined cooling, heating and power system driven by solar energy

A new combined cooling, heating and power (CCHP) system is proposed. This system is driven by solar energy, which is different from the current CCHP systems with gas turbine or engine as prime movers. This system combines a Rankine cycle and an ejector refrigeration cycle, which could produce cooling output, heating output and power output simultaneously. The effects of hour angle and the slope angle of the aperture plane for the solar collectors on the system performance are examined. Parametric optimization is conducted by means of genetic algorithm (GA) to find the maximum exergy efficiency. It is shown that the optimal slope angle of the aperture plane for the solar collectors is 60° at 10 a.m. on June 12, and the CCHP system can reach its optimal performance with the slope angle of 45° for the aperture plane at midday. It is also shown that the system can reach the maximum exergy efficiency of 60.33% under the conditions of the optimal slope angle and hour angle.     

Research,development and the prospect of combined cooling,heating, and power systems

The development of a combined cooling, heating, and power (CCHP) system in China is presented in this paper. The key scientific problems of a distributed energy system and the integration principles of a CCHP system are also pointed out. Moreover, two corresponding CCHP systems: one with the complementarities of fossil fuels energy and renewable energy, and the other integrated with desalination technology, are investigated. With special attention to thermal energy utilization, the integrating characteristics of these systems are likewise revealed, and the important role that the principle of cascade utilization of physical energy plays in system integration is identified. We have found that the energy-saving ratio of the integrated CCHP systems can be as high as 30%, and as such, the innovative CCHP systems suitable for China's sustainable development are also recommended.     

燃气轮机进气喷雾蒸发式冷却与Li-Br吸收式制冷冷却增能对比分析

燃气轮机进气冷却技术是一种能够有效提高高温环境下燃气轮机发电机组输出功率的重要手段。介绍了几种主要的进气冷却技术方法,并分析了进气冷却技术的作用机理。着重对比分析了华菱涟钢能源中心所采用的两种进气冷却技术对燃气轮机输出功率的影响规律,并阐明了两种进气冷却技术各自的优缺点。根据运行参数以及相关数据分析的对比研究结果,为燃气轮机进气冷却技术在实际工程上的应用提供一定的参考。     

高炉余能余热驱动的内可逆闭式布雷顿热电冷联产装置火用经济性能分析

用有限时间热力学理论研究恒温热源条件下由一个内可逆闭式布雷顿热机循环和一个内可逆四热源吸收式制冷循环组成的高炉余能余热驱动的热电冷联产装置的火用经济性能,导出热电冷联产装置的利润率和火用效率与压气机压比的关系。利用数值计算,分析热电比和吸收式制冷循环总放热量在吸收器和冷凝器之间的分配率对利润率与火用效率关系的影响,并研究联产装置各种参数对最大利润率及相应火用效率特性的影响。     

Review of passive solar heating and cooling technologies

Heating, ventilating, and air-conditioning (HVAC) are parts of the major energy consumption in a building. Conventional heating and cooling systems are having an impact on carbon dioxide emissions, as well as on security of energy supply. In this regard, one of the attempts taken by researchers is the development of solar heating and cooling technologies. The objective of this paper is to review the passive solar technologies for space heating and cooling. The reviews were discussed according to the working mechanisms, i.e. buoyancy and evaporative effects. The advantages, limitations and challenges of the technologies have been highlighted and the future research needs in these areas have also been suggested.