Scheme Evaluation Analysis Of Natural Gas Combined Cooling, Heating And Power System

In recent years, with West-East Gas Pipeline and natural gas of Shanxi, Gansuand Ningxia into Beijing, adjustments of energy structure are happening in theeastern large and medium cities of China. And the traditional primary energy whichis given priority to the coal is replaced by natural gas. However utilization ofprecious natural gas resources in the city is burned off directly. How to apply naturalgas more reasonably in cities? One of the effective ways is to utilize the system ofcombined cooling, heating and power. The system makes use of natural gas anddrives the generator to produce electricity. And then its waste heat is used for heatingor driving absorption chiller to refrigerate. Thus it realizes energy’s cascadeutilization so as to create conditions for efficient use of natural gas. At the same time,in the past two years, major cities across the country are faced with different levelsof power supply tension, especially in major cities of the east. In order to alleviatethe situation, countries also introduced some incentives accordingly to supportpopularization and application of combined cooling, heating and power technologyas the leading factor of distributed energy system.This paper expatiates on the system of combined cooling, heating and power andits characteristics and simply analyzes system’s working principle. And from theperspective of energy form, the system is divided into power system and thermalsystem. The two parts are introduced respectively.This article also puts forward evaluation method of CCHP system. That is, toevaluate the plan comprehensively by three aspects of energy efficiency,environmental protection and economy. First of all, the energy efficiency’sbenchmark selection is introduced. Next put forward the definition and calculationmethod of energy saving rate; secondly, about the environmental assessment,introduce how to determine pollutant emission factor and calculate system’s reductionrate relative to gas production system; finally, for economic evaluation, this paperintroduces the concept of incremental evaluation and analyzes the calculation processof various economic indicators. And then put forward the incremental evaluationmethod of CCHP system. It is pointed out that the evaluation method can avoidinterference of artificial factors such as heat price or cold price and make understanding of project technology economy more objective. At the same time, theincremental method will make CCHP system equivalent to a pure power plant toavoid the interference such as heat price or cold price and make system complexeconomics problem become simpler and clearer.Finally, take the energy system of a university in Beijing for example to discussthe evaluation method of CCHP system from three aspects of energy efficiency,environmental protection and economy. And then put forward the optimal scheme ofthe energy system.