Numerical Simulation And Experimental Studies On Combustion Process Of The Novel Gas Instantaneous Water Heater

With the improvement of people's living standards and requirement of the urban air pollution decrease, the whole country is making all-out efforts to develop city gas. During the widely used process of gas, gas instantaneous water heater is the gas user's main hot water provides equipment at present. But the combustion heat transfer device of the gas water heater on sale now is not perfect. Thus, how to make good use of the high quality energy, and how to improve the efficiency of the combustion attracted widespread attention。This article uses computational fluid dynamics software FLUENT to carry on the numerical simulation computation of the new gas instantaneous water heater. The aim is to draw water heater combustion process in specific details, identify some impact factors and characteristics of the water heater combustion process. It can be taken as the guidance and reference to the water heater design and the practical operation. Meanwhile, using numerical simulation method on water heater combustion is also one kind of new exploration which studies to the water heater.Through building a mathematical model of gas water heater and using the non- structure grid and the K ?εdouble equation model as a turbulence model, we can establish the closed equations composed with the continuity equation, the momentum equation component, K equation andεequation. Using eddy dissipation components combustion model, definition boundary conditions in turbulent flow of chemical composition mix and reaction, separation solver used for initialization and solve combustion model, we can obtain the temperature,pressure distribution of gas water heater, as well as CH4, O2, NO mass fraction of the concentration of distribution in combustion process. Through these distributions, the temperature field and each kind of combustion component characteristic were obtained, including some problems that in the design needs to be pay attention to. Through changing the air speed of flow in the software control panel, the difference of the combustion temperature and each kind of gas mass concentration distribution under the different excess air coefficient was obtained. Moreover, according to the calculation of water heaters ejector, we found it cannot satisfy inject request. Here, the author suggests to use negative pressure ejector, and calculated its size. Meanwhile, with the experiment of the gas water heater, by comparing the temperature and haze measurement result, difference between the analog...