Combined cooling, heating and power: A review of performance improvement and optimization

Analysis and optimization of CCHP systems based on energy, economical, and environmental considerations

The combined cooling, heating and power (CCHP) system – a typical representative of the decentralized energy system – has been increasingly attracting attention in academia and industries in recent years, thanks to its distinctive advantages of high system and economic efficiency, and less greenhouse gas (GHG) emissions In this paper, the state of the art of CCHP research is surveyed First, the development and working scheme of the CCHP system will be presented Some analyses of the advantages of this system and a brief introduction of the related components are then given in the first part In the second part of this paper, we elaborately introduce the prime mover and thermally activated facilities Recent research progress on the management, control, system optimization and sizing will be summarized in the third part The development of the CCHP system in representative countries and the development barriers will be discussed in the last part

Combined cooling, heating and power systems: A survey

Heating and cooling energy requirements for buildings are usually supplied by separated systems such as furnaces or boilers for heating, and vapor compression systems for cooling. For these types of buildings, the use of combined cooling, heating, and power (CCHP) systems or combined heating and power (CHP) systems are an alternative for energy savings. Different researchers have claimed that the use of CCHP and CHP systems reduces the energy consumption related to transmission and distribution of energy. However, most of these analyses are based on reduction of operating cost without measuring the actual energy use and emissions reduction. The objective of this study is to analyze the performance of CCHP and CHP systems operating following the electric load (FEL) and operating following the thermal load (FTL), based on primary energy consumption (PEC), operation cost, and carbon dioxide emissions (CDE) for different climate conditions. Results show that CCHP and CHP systems operated FTL reduce the PEC for all the evaluated cities. On the other hand, CHP systems operated FEL always increases the PEC. The only operation mode that reduces PEC and CDE while reducing the cost is CHP-FTL. Copyright © 2009 John Wiley & Sons, Ltd.

Performance analysis of CCHP and CHP systems operating following the thermal and electric load

The serious energy supply problems along with the conventional resources depletion and the environmental conscience regarding global warming and climate change have urged the need for a complete change in the energy production, supply and consumption patterns. Therefore, the switch towards renewable energy resources including solar, biomass, wind and hydro-power in addition to the development of energy efficient technologies are two key factors to attain a secure and reliable energy sector and to mitigate the global warming problem. Tri-generation is one of the most promising technologies allowing the efficient simultaneous production of heat, coolth and power with potential technical, economic and environmental benefits. This paper provides a comprehensive review of the latest developments in the field of combined cooling, heating and power generation. Recent tri-generation supporting mechanisms, prime movers, cooling technologies, system configurations, fuels and renewable energy resources employed are presented and discussed. As the operation strategy is the critical factor governing the tri-generation system performance, the current work presents the recent strategies developed and implemented to optimize the system performance and improve its overall efficiency. While certain technologies employed in tri-generation systems as internal combustion engines, gas turbines and absorption cooling are well-established and have already found their way to the commercial market, other promising technologies including organic Rankine systems, fuel cells and liquid desiccant cooling, are still in the research and development phase with additional work needed to demonstrate their potential and reach commercialization. Based on the detailed and comprehensive review conducted, a summary with the main conclusions in addition to recommendations for future work are reported.

Tri-generation systems: Energy policies, prime movers, cooling technologies, configurations and operation strategies

The increasing demand for electrical power as well as energy for heating and cooling of residences and small commercial buildings is a growing worldwide concern. Micro-cooling, heating, and power (micro-CHP), typically designated as less than 30 kW electric, is decentralized electricity generation coupled with thermally activated components for residential and small commercial applications. The number of combinations of components and parameters in a micro-CHP system is too many to be designed through experimental work alone. Therefore, theoretical models for different micro-CHP components and complete micro-CHP systems are needed to facilitate the design of these systems and to study their performance. This paper presents a model for micro-CHP systems for residential and small commercial applications. Some of the results that can be obtained using the developed model include the cost per month of operation of using micro-CHP versus conventional technologies, the amount of fuel per month required to run micro-CHP systems, the overall efficiency of micro-CHP systems, etc. A case study is used to demonstrate differences in the system performances of micro-CHP systems driven by a natural gas internal combustion engine and a diesel engine. Some of the results show that both systems have similar performance and that system total efficiencies in cooler months of up to 80% could be obtained. Also, modeling results show that there is a limit in fuel price that economically prevents the use of CHP systems, which is $11 MBTU−1 for this specific case. Copyright © 2008 John Wiley & Sons, Ltd.

Thermoeconomic modeling of micro‐CHP (micro‐cooling, heating, and power) for small commercial applications

The increasing demand for electrical power as well as energy for heating and cooling of residences and small commercial buildings is a growing worldwide concern. Cooling, Heating, and Power (CHP) is a promising technology for increased energy efficiency through the use of distributed electric and thermal energy delivery systems at end-user sites. Micro-cooling, heating, and power (micro-CHP) is decentralized electricity generation coupled with thermally activated components for residential and small commercial applications. Micro-CHP systems, typically designated as less than thirty kilowatts electric, can simultaneously produce heat, cooling effects, and electrical power. The number of combinations of components and parameters in a micro-CHP system are too many to be designed through experimental work alone. Therefore, theoretical models for different micro-CHP components and complete micro-CHP systems are needed to facilitate the design of these systems and to study their performance. This paper presents a model for micro-CHP systems for residential and small commercial applications. Some of the results that can be obtained using the developed model include: the cost per month of operation of using micro-CHP versus conventional technologies, the amount of fuel per month required to run micro-CHP systems, the overall efficiency of micro-CHP systems, etc. Also, this model allows to evaluate micro-CHP systems using different type of fuels such as: natural gas, propane, biofuels, etc, to determine the fuel that provides the best performance.© 2006 ASME

Alan Moran

Papers

Thermoeconomic modeling of micro‐CHP (micro‐cooling, heating, and power) for small commercial applications

Modeling of Micro-Cooling, Heating, and Power (Micro-CHP) for Residential or Small Commercial Building Applications