Integration Principia And Performance Of CCHP System With Gas Turbine

Being a kind of total energy system that faces directly the end-user, CCHP is the branch of DG with the clearest prospect, and it could meet multi-kinds of energy demands and actualize multi-kinds of objects. Supported by the key project (No.2002AA503020) of 863 Program, the NSF of China (No.90210032) and Olympic Energy Park project, the dissertation researches the integration & evaluation of CCHP, the thermodynamic performances in the design-load & all-operation regions of CCHP with gas turbine, and the exploitation of the novel CCHP.Based on the principle of "matching of the temperatures for cascade utilizing the energy", the integration principia of CCHP is proposed. We should pay attention to the levels of thermal energies, and the interaction between different subsystems. The cascade utilization of the thermal energy is the main principle, and the all-operation regions performance, economics & the real user demands are considered, finally, we should adjust measures to local conditions. These results offer the theoretical base for the applications of CCHP.Both the evaluation criteria and the performance of saving energy of CCHP are studied. The fuel-utilization efficiency thinks all outputs as equal, and the exergy efficiency emphasizes egregiously the work availability, and the artificial thermal efficiency distorts the effects of cooling & heating outputs, so they are unfit for evaluation of CCHP. The economic-exergy efficiency reflects the markets demands, and FESR checks the saving fuel, thus they are fit for evaluation of CCHP. In addition, through analyzing the effects of the subsystems parameters and supplement fuel amount on the system, the dissertation puts forward the condition if the system could save the energy, and obtains the verdict how the recovered thermal energy should be used preferentially.All-operation regions of CCHP with gas turbine are studied. CCHP performances are raltive to the temperature ratios and the pressure ratios. In CCHP with simple gas turbine, the optimal pressure ratio of FESR is lower that that of thermal efficiency. As to CCHP with recuperative gas turbine, within the study range, if the heat transfer temperature differences are the same, the optimal pressure ratio of FESR is higher that that of thermal efficiency, and it is about 3.4. FESR of CCHP with simple gas turbine is lower than that of with recuperative gas turbine, and they decrease with the loads decreasing. If the power outputs decrease up to 10% of rated load, the advantages in saving energy maybe vanish. The FESRs decrease obviously in all-operation regions, but if the storing system is used or the adjustable recuperative gas turbine is used, the performance in all-operation regions would be improved greatly.A novel CCHP system with the renewable energy is proposed. In the system, the absorption chiller and the electric heat pump complement each other: in heating mode, they operate as heat pump, and the output of the electric heat pump acts as the input of the absorption chiller, and they form an integrated heat pump; in cooling mode, they operate in parallel mode, and the electric heat pump is the supplement of the absorption chiller. The renewable energy acts as the low-temperature heat source of the heat pumps in heating mode, and they are the "sink" of the chillers in cooling mode. In a representative case, it is found that FESRs are 45.6% and 31.6 in rated heating mode and cooling mode respectively, and these FESRs are higher 10 percentage points than that of traditional CCHP.