Composite Phase Change Heat Storage Material Filling The Regenerator In The Numerical Simulation Of Thermal Process

High Temperature Air Combustion (HTAC) technology is, a new combustion technology arising internationally in the early 1990s. It integrates the technologies of recycling flue gas heat, promoting high-efficiency combustion and decreasing NO_X emission systematically into a new technology, which is characterized by some advantages, such as energy economy, high utilization ratio of heat, low NO_X emission and small scale furnace. This technology has made a rapid progress in the latest years because of its advantages of energy economy and pollution-free quality.The thesis includes a review of the history and status quo of HTAC, the elaboration of its principles and characteristics and the introduction of the previous studies on HTAC home and abroad. And then the key components of regenerative heat exchanger—the preparation and material selection of the regenerator—are summarized, and our lab's patent—the technology of the process and preparation of new high-performance composite regenerator—is presented at the same time. In view of the immaturity of present experimental conditions, large commercial CFD software—FLUENT can be used to establish a numerical model about heat process of high-temperature composite phase-change regenerative materials filling regenerative heat exchanger. Therefore, a numerical simulation research on the process of heat input and heat output is made, and the simulative result of computation can account for the following conclusions:First, a preliminary success has been achieved in the research on utilizing CFD software FLUENT to establish numerical model about heat process of honeycomb regenerator filling regenerative heat exchanger, and the unsteady coupled computation of two phase convection, conduction and radiation is realized.Second, the result of the numerical simulation reveals clearly that, with the differences of time, heat-exchange liquid temperature and flowing rate in the process of heat storage and heat output, honeycomb regenerator's temperature distribution isn't very uniform. And the non-uniformity ismajor reason for the breakage of Regenerator in the process.Third, the distribution of the high and low temperature areas depends on the initial velocity at which the smoke and warm-up air get in the regenerative heat exchanger through nozzle, and the relative size of regenerative heat exchanger and regenerator. It is required that, when choosing the sizes of regenerative heat exchanger and the parameters of burner in the optimized design of regenerative heat exchanger, not only is the output of furnace regarded as a standard, but the elements including initial velocity of the heat-exchange liquid and the direction-exchange time should be taken into consideration.Fourth, in the result of simulation computation, compared with the traditional heat-shown regenerator, the regenerator using the cpmposite phase-change regenerative materials makes the change of smoke temperature in the mouth much slower. Under the requirement for the same smoke temperature in the mouth, the direction-exchange time can be further lengthened so that the service life of the regenerator and correlative components is prolonged, and the frequency of maintenance is also reduced, thus the cost drops greatly.Compared with other numerical models of the regenerative materials, the numerical model based on computing hydrodynamics theory has less limitation of supposing condition, but has flexible boundary condition. It can simulate different operating modes and shapes of furnace. The, data set of the temperature field and flow field obtained from the numerical model can be showed in a visible form. It provides a new thinking for the primary research on the heat diffusion of honeycomb regenerator, as well as for the researches on the optimization of structural size and the operation controlling parameter.