| Combined cooling, heating and power (CCHP), which is attracting more and more attentions, is a well-known technology of sufficient utilization of low-grade thermal energy with the principle of thermal cascading. The small-scale internal combustion (I.C.) engine based CCHP system enjoys the merits of good economic efficiency, flexibility and adaptability. The I.C. engine based CCHP system can absorb the thermal heat from jacket water and exhaust gas, the amount of which is always determined by the power generation. The operation characteristics of this kind cogeneration system are characterized by multi-heat inputs/outputs in combination with jacket water temperature control. To solve the practical problem of high initial cost, low flexibility and reliability of conventional method, a novel device of integrated Thermal Management Controller (TMC) is presented in this thesis. Based on pure thermodynamic process, the TMC effectively realize the function of heat source temperature control and waste heat recovery/management. Profound theoretical analysis is made to point out its further improvement. High reliability and good stability of the TMC have been proven by the experimental results. Combined the devices of 16kW I.C. gas engine, adsorption chiller and TMC, a movable micro-scale CCHP system is established, which is a great contribution to the commercialization and practicality of CCHP system. To draw a conclusion, the main works are summarized as following:(1) To solve the practical problem encountered in the application of I.C. engine based CCHP system, the concept of Thermal Management Controller (TMC) is presented based on the working principle of Temperature Control Heat Pipe (TCHP). The TMC, which is an integrated thermal management platform, can automatically realize the function of heat source temperature control and thermal management. It has been applied for national patent. Compared with the conventional thermal management method, the suitable application area and characteristics of the TMC are drawn.(2) Through the development of the TMC experimental prototype and testing system, the working principle is validated and important experimental data is accumulated. In the experiments, the stable and dynamic performance of the TMC, and the influence of working fluid and non-condensable gas are studied in details.(3) Based on the flat front model, the working process of the TMC is established. By the comparison of simulation and experiment results, the theoretical model is modified and broadened the application area of flat front model. Based on the modified model, the working process of the TMC is simulated and the influencing factors are analyzed. The theoretical results point out the direction of optimum design.(4) Based on the modification of theoretical model, the engineering prototype of the TMC is constructed. Combining the 16kW I.C. gas engine, adsorption chiller and the TMC, a movable micro-scale CCHP system is established, which is a good demonstration for the application of MCCHP system.(5) Through the experiments, it is proved that the TMC can effectively realize the function of jacket water temperature control and thermal management in different working conditions. The overall efficiency of the system is approximately 75.3%. In the designed limit working conditions, the variation of jacket water temperature is only 5.4°C. At the same time, the efficiency of the TMC reaches 90%. When the adsorption chiller is used as the heat consumer, the TMC still keeps a good performance of temperature control. The variation of jacket water temperature is within 2°C, and the TMC does a good job in thermal management.(6) All research work is summarized and the directions about the TMC are discussed.
|
PDF Full Text Request