Study On Dynamic Characteristics And Control Strategy Of Thermal Rotary Regenerator

Rotary Air-preheater is one of the main auxiliaries in heavy-duty plant. Low temperature corrosion and high leakage are the intractable problems existing in it, which affect security and economy seriously. Based on the structure designed, mathematics models are established correspond to dynamic characteristics mechanisms of low temperature corrosion and leakage are investigated generally, control strategy of seal clearance is put forword. The main originality innovations in the dissertation are:To prevent low temperature erosion and analyze thermal distortions in it, supervise the metal temperature performance and install air-warm machine to improve temperature level are needed. An analytical-numerical computation method was provided to simulate the temperature distribution in rotary air-preheate inner, which includes matrix and fluids 3D temperature pattern and the results are definitude and exactitude, an applied tool is provided in the form of line abac. Through analyzing of economy benefit, scheme of air-warm machine's operation is abstracted also.Rotary air-preheater is optimum designed from various aspects, relationship of structure parameter and aim function is set up, then the regenerator assembly principle is selected out also, which provide reference to manufactory.It is analyzed and proved theoretically rotor-housing"mushroom"thermal distortions based on matrix temperature distribution, the method proposed permits one to evaluated leakage pattern within steam boiler rotary regenerators.Point out insufficiency of national criterion expression in appraising capability of air-preheater and export an testing expression considered fuel property. Derive a model describing the network leakage, taking into account of rotor structure, medium parameter and fuel component etc. Leakage paths shown in the network is clear and distinct, which can guide airproof leakage adjustment and improve regenerator efficiency and reliability.The analysis and minimization of the irreversibilities associated with the rotary regenerator will be useful if an increase in power plant efficiency results. Based on entropy generation theory in thermodynamics, gas enthalpy-entropy model is established also, it is convenient to evaluate the irreversibilities associated with air-preheater only and to show their relationship to the efficiency of a steam power plant. It is useful for drawing conclusions to show the final leakage effect on the difference in efficiency of a steam power plant with no leakage and with leakage. Gas enthalpy model can be indicated the most economical fuel angle and entropy model can be simulated the most oecumenical leakage distribution.Fuzzy control theory system is adopted into adjusting automatically of radial seal clearance at hot end, this production can make up the flaw of low precision and short life-span in control system existing, it has been validated by theory and verified by experiment.This dissertation has comprehensive investigations on rotary air-preheater economic characteristic and control strategy, a series achievements are obtained, which means much in both theory and practice.