Studies on thermal radiation ignition of coal-water slurry

The generally applied ignition method on the coal combustion boilers at the present all over the world is either the oil-ignition method or the gas-ignition method. The power plants in China Consume 500,000 tons of oil for ignition every year. To save on the ignition oil, we China has broadly developed the non-oil or little-oil ignition technologies since 1980`s, and made a great achievement. Either non-oil ignition or little-oil ignition technology, the key is to design the proper pre-combustion chamber and the economical and liable ignition energy source, and ignite the boiler with the least cost. The coal-water slurry, which is applied to replace the oil, is generally researched and tested by a lot of countries, such as Japan and Russia etc. Since 1986, Japenese carried on the industrial tests on a 75MW and a 600MW unit for a long time; Russian have constructed a large scale performing engineering for the coal-water slurry producing, pipe transportation and combustion. They combust the slurry on a 200MW boiler at the New Sibria heat-electricity power plant and practice successfully. Chinese also combust the slurry on several industrial boilers successfully and plan to test on the power plant boiler, but the ignition method ismore » still the convent method. The principle is as follows: to heat the ignitor inner wall with electricity, and raise it`s wall to a high temperature, as soon as the CWS is sprayed into ignition chamber, it receives the wall radiant heat and the droplet temperatures rise quickly to ignite point. The experiments have shown that this ignition technology merely consumes little electric energy, operates easily, ignites quickly, the ignition cost is very low and this technology is easily practice in the plant.« less