Study Of Optimization Of Heat Recovery Steam Generators For Building Cooling Heating & Power Generation Systems

Currently, The energy's development and usage are facing the bigness pressure in the economy increase and the environmental protection, making use of the energy validly and reasonably has became the sustainable development's crux in our country. The project which our country are consuming the enormous investment to construct transporting the natural gas from west to east is one of the measure to reply this pressures. The Building Cooling Heating and Power Generation (BCHP) system can realize not only the most reasonable usage to the primary energy but also the best path and the most valid means to make use of the natural gas resources. But recently in our country the initial investment and the fuel costs of BCHP system are higher, so in this case it is necessary to optimize the important equipment-Heat Recovery Steam Generator (HRSG) to make the whole system have the best thermal-economic, and it will have the important meaning to popularize the BCHP system smoothly in our country.According to the practical result for a running BCHP system, the thermal model of HRSG was established. Because there is not the special cost apportionment method for the products of the BCHP system, on the bases of analysis the cost apportionment methods for Combined Cycle, with the workability and calorific methods and using operating data of the system, the costs of unit amount of exergy of cool, heat and electric power were calculated by apportioning the overall cost of the system among the cool, heat and power. The cost apportionment method to the whole system was established. The cost-evaluation model of HRSG was also established, the data and empirical correlations used in cost model are all from domestic manufactures and hence are real and practical.For the optimization function of HRSG, the cool costs is considered as the objective function and the variables are the number of row, the number of tube per row, the horizontal distance and vertical distance between tubes of the Evaporator and the Economizer. Using the optimization model, the optimization results can be calculated respectively on the off-design performance of the system, discussions on the calculation results were carried out. A group of optimal parameters of HRSG can be received by combined the models in this paper and the chart of the BCHP system's actual load.Based on the optimal results an important conclusion can be predicted out that the optimal structure of HRSG are related with the load characteristic of the BCHP system. Furthermore, the factors which affect the load characteristic of the BCHP system were analyzed, finally, it was pointed out that the optimal structure of HRSG just be applicable to a particular BCHP system and so it cannot be used generally.