Optimal Design Of Building Cooling Heating And Power System And Its Multi-criteria Integrated Evaluation Method

The sustainable development is being popularized in the world and the subjects such as improving the utilization efficiency of energy and protecting the environment are increasingly prominent. Consequently, building cooling, heating and power (BCHP) system, one of the secondly generation energy technology, is broadly paid more and more attention to. This thesis combined with the climate zones and the energy demands of public buildings to deal with the BCHP system, explored and analyzed the performances including thermodynamics, economy, environmental impact and reliability, etc, optimized the structure and the operation strategy of BCHP system from the energetic, economic and environmental characteristics, and compared the integrated performance of BCHP system applied to the different buildings in different climate zones in China, which would be beneficial to its development in China and to the sustainable goals of energy system.Firstly, based on the design standard for energy efficiency of public buildings in China, this paper simulated the hourly cooling, heating and power loads of four different styles of building (hotel, office, hospital and mall) in five different climate zones (severe cold, cold, hot summer and cold winter, mild, and hot summer and warm winter) using the software DeST. The energy demands including cool, heat and power of the buildings were presented and analyzed.Secondly, a traditional separation production system to supply cool, heat and power to building was referenced and a general redundant BCHP system was proposed and designed. The evaluation criteria for BCHP system was compared and analyzed. A hotel in Beijing was selected to be a case study, and the BCHP systems which operate with the central electric grid or without the grid were constructed. Moreover, the energetic, economic and emission performances of BCHP systems following the thermal load and the electrical load were respectively analyzed and compared. Then, the sensitivity of the performance of BCHP system to the technical, economic and emission parameters was studied and the effect potential was obtained.Thirdly, to begin with the optimization problem, the optimization model of a redundant BCHP system for a hotel in Beijing was constructed. The variables, objective function, constraints and solving method were described. The genetic algorithm was employed to solve the optimization problem and to obtain the optimal capacity and the best operation mode. The reliability of the optimization model was verified. The operation performances including the annual performance and the seasonal performance were obtained and then compared to the performances of the traditional BCHP system. Then, the sensitivity of the performance of BCHP system to the prices of electricity and natural gas was analyzed.Then, there were presented the criteria selection, the normalization, the weighting methods including subjective weight, objective weight and combination weight, the evaluation method and the aggregation method during the multi-attribute evaluation of BCHP systems. The multi-attribute integrated evaluation model for BCHP systems was constructed, which was applied to the comparison between the BCHP systems for different buildings in the five climate zones in China. The application conclusions of BCHP system in China were obtained.Finally, the Markov model and the state space method were employed to analyze the effect of the failure rate and the repair rate of the equipments to the availability and reliability of BCHP system. The reliability analysis models including the redundant BCHP system and the traditional BCHP system were proposed respectively. The reliabilities of supplying cool, heat and power for building from the redundant BCHP system, the traditional BCHP system and the separation production system were compared.