Study Of The Rules Of Distribution For Gas Detonating Shock Wave And Applications On Boiler Ash-clearing

Through study the super-pressure and distribution rules of detonating for a one-hole vessel, which is full of air- ethyne mixed gas. Use and control the energy of detonating shock wave in reason, to clean the ash which accumulating on the surface of boiler heaters, and to solve some problems that occur in the process of engineering application, in order to solve the difficult problem of ash accumulating.At present, all kinds of Soot-blower have been used in every types boiler heaters ash cleaning, but those soot-blowers exist some flaws, such as consumed high energy, reliability and cleaning effect bad, etc. And some side effects harmed equipment. This paper introduces the status of study gas detonating, gas-detonating-types soot-blower, the theory research of gas detonating and the mechanism of ash accumulating on the surface of boiler heaters. Emphases studied the chemistry component and ash-accumulating characteristic for two power plants. As the gas detonating shock wave soot-blowers usually use ethyne as fuel, so introduce ethyne's characteristic, such as ignition point emphases, ignition energy, explode limit, detonating of disassemble and the ability of transmit.The air- ethyne mixed gas explode is a typical gas-phrase detonating. As easy to seek the solution of flow-field which after air- ethyne mixed gas detonating. It must unbind the C-J parameter of gas-phrase detonating. Assume the exploders and productions are ideal gas, and obey ideal-gas equation. As the process of detonating and transmit is very quickly, so this process can be considered as entropy equation process. According Hugoniot equation, ideal-gas equation, entropy equation, mass and momentum equation, we will figure out the C-J parameter of gas-phrase detonating, such as pressure, temperature, velocity and density. Using VB computer language we will write programs to calculate C-J parameter of gas-phrase detonating. The calculate result have some error, the reason may be that detonating products decompose don't take into account. Despite this, used the programs to calculate C-J parameter as the initial value, there are more credibility for safety design and safety evaluate.Through establishing grid numerical value and control equation, disperse pressure domino effect steps and transportation steps by controlvolume cell methods, and than circulative calculation detonating shock wave's pressure and velocity. The study reckoned that detonating has distribution rules there in after for a one-hole vessel, which is full of air- ethyne mixed gas:The pressure on axis is more greater than that on radial, the pressure on axis is about 1.0mpa, 30-40 times as same as that on radial.The distance that to the open hole is longer, the pressure and velocity on axis is lower, and attenuation quickly.The ethyne equivalent weight bigger, the detonating pressure on axis is increase, when the ethyne equivalent weight is 1.0, the detonating pressure on axis is the biggest, and then will be decrease.As diameter of the hole is smaller, the detonating pressure on axis is lower.The maximal velocity of detonating transportation is about 2290m/s.For the engineering application, this paper introduces the base principle of shock wave soot-blower and the characteristics of soot-blower alteration. The soot-blower alteration has fully taken into account the constructers of economizer, boiler running condition and the situations of ash on the economizer. The cleaning areas of shock wave soot-blower can bestrew about 80 percent of economize surface. The constructer of shock wave occurs devices are designed accord with the boiler running condition. The detonating energy is proper. Used the high- energy-ignited device to insure detonate successfully and boiler tube's safe. And solved the key-technology problems, such as gas self-ignite, backfire when the Shock wave Soot-blower be used in the high temperature areas. This technology has been successfully applied in utility boilers ash cleaning, It has features reliable performance, easy maintenance, low initial investment, greatly reducing flue gas temperature, and increased boiler thermal efficiency, with remarkable energy saving benefit gained.