Study On The Testing Method Of Jet Parameters In A High-pressure Coal Gasification Quench Process

Coal gasification technology as a clean coal technology has been widely applied and developed rapidly. SHELL coal gasification is one of the most advanced methods of coal gasification field so far. For increasing gas production, reducing costs, we improve the cooling technology of the compound gas, replace the compound gas quench technology with water quench technology. But, there is no industrial example of the water quench which is applied on the dry-pulverized coal gasifier. In order to industrial application, researches on water jet process in high temperature and ambient pressure should be done. Since there are few formulas to get the parameters of water jet in high temperature and ambient pressure, so, experiment should be performed to get the parameters of water jet.Parameters in water jet process include spray cone angle, velocity and particle size distribution generally. In this paper, we focus on spray cone angle and velocity field which related to the water quench process closely. According to the requirements of quench process, we designed a high temperature and ambient pressure experiment system, and made a full discussion of the testing of spray cone angle and velocity field in water jet process.High-speed digital imaging method was used to determine the spray cone angle, and a camera was used to capture images, we get the spray cone angle after the image processing, PIV was used to determine the velocity field. The experiment results show that the edge of the water jet is regular, and has no distortion almost, so we can use simple image processing methods to get the data for reducing experimental error in complex image processing.It is proved that reflection intensity of the water meet the requirements of the tracer particles in some region after velocity field is got by PIV. According to the experiment, it is found that the quality of velocity vector images after processed from the image captured CCD show a low - high - low trend with the injection pressure and ambient pressure increasing. This is because the increasing of pressure cause atomization intensity increasing which cause the number of particles increasing, so the particle information in the testing regions increase, however, there are some difficulties in CCD identification and correlation processing because of the high particle density causing by pressure increasing. We can use two methods, high resolution and seeding tracer particles, to solve the high particle density problem. In addition, near the exit of the nozzle, because of the poor dispersion of particles, the particle density is too high and particles bond with each other, the high resolution method performs poor in this region, we recommend using other methods to measure. With regard to the high reflection intensity in the central region of the jet near the exit of the nozzle, we use the water staining method to reduce the reflection intensity in the central area of the jet, simultaneously retain the particle information in the edge of the jet, through this method, we get good results.