Papers by Keyword: Combined Heat and Power (CHP)

Abstract: CO₂ is the main determining factor for global climate change. For this reason, the emissions of this gas have to be reduced as much and as quickly as possible. This paper discusses the possibility to realize a CO₂-neutral heat and power supply for single and multi-family homes. There have been a lot of studies in the past, as well as several unsuccessful-attempts to commercialize such a system. However, this paper presents a new and simple 1 kW_el setup for a smart combined heat and power (CHP) plant offers solutions for the deficiencies of previously published and demonstrated systems. A commercial pellets firing system is linked with an organic Rankine cycle (ORC), which is built with mass-produced parts. In addition, inexpensive and proven-in-use hot-water storage tanks are used as an energy buffer and for storage, resulting in reduced investment costs. Furthermore, we demonstrate that it is necessary to embed such a system into a smart home environment in order to achieve an efficient and profitable setup.

Abstract: The advantages of high energy efficiency and economic benefit promote the wide application of combined heat and power system (CHP) based microgrid. Firstly, a mathematical model of the CHP based microgrid is developed. Then, a cost function for the coordination of heat and electric load is proposed. Finally, an optimal dispatch model is developed to achieve the economical and coordinated operation of the CHP based microgrid system. Simulation results verify effectiveness of the proposed dispatch model, which is a powerful tool for the energy management of CHP based microgrid with renewable energy resources.

Abstract: Fuel cells are devices for electrochemically converting the chemical energy of a fuel gas into electrical energy and heat without the need for direct combustion as an intermediate step. The main advantages of fuel cells are that they rely on the high conversion efficiency and low environmental impact than traditional energy conversion systems. One promising fuel cell type, Solid oxide Fuel Cell, has all the components in the solid phase utilises nano-ceramic composite materials and operates at elevated temperatures in the range 500-1000°C. It has suitable perspectives to replace their classical counterparts for the distributed generation of electrical energy with small and medium power sources. The inherent advantages of such high temperature fuel cells are internal reforming of methane and waste heat production at high temperatures which lower the demands on the fuel processing system and lead to higher efficiency compared with low temperature fuel cells. Using natural gas as feed, an electric efficiency of more than 88% has been predicted. On the other hand, considerable research is going on to reduce the operating temperatures between 600°C to 800°C to increase life-time and thereby reduce costs. These can be achieved only by using electrolytes with proper ionic conductivity at the intermediate temperatures. In addition, this technology does not produce significant amounts of pollutants such as nitrogen oxides compared with internal combustion engines. Solid oxide fuel cells are seen as ideal energy sources in transport, stationary, and distributed power generators.

Abstract: The working principle of the micro-CHP based on biomass direct-fired Stirling engine and the thermal energy conversion process of the biomass direct-fired fuels were analyzed. On the basis of analysis, a 1kW β-type Stirling generator was designed and constructed for lab tests. Then, experiments were carried out to evaluate the effectiveness of the prototype. Through the analysis of experimental data and simulation, the change law of charge voltage, charge current with the engine speed and pressure, as well as the relation of heat and electricity, the power generation efficiency and the overall efficiency of the thermoelectric in the working process was obtained. The results showed that biomass energy use efficiency will be improved through the use of micro-CHP based on biomass direct-fired Stirling engine.