Energy-saving Research On Regenerative Waste Heat Recovery For Thermal Plasma Medical Waste Treatment System

With the continuous advancement of Chinese medical industry,the output of medical waste is increasing year by year.Meanwhile,the types of medical waste are complex and harmful.Therefore,the treatment of medical waste has become the focus of attention.Thermal plasma medical waste treatment technology has many advantages,such as thorough decomposition of dioxins and harmless by-products.However,the traditional thermal plasma medical waste treatment system has the drawback of high power consumption.In this study,the energy-saving potential of thermal plasma medical waste treatment technology was analyzed by theoretical calculation method.Then,a set of experimental system was set up and preliminary experimental tests.were completed by combining waste preheating,high-temperature air gasification,high-temperature air combustion and waste heat limit recovery.In terms of theoretical calculation,the heat transfer model of garbage preheater is proposed.The rotary preheater designed can use high temperature air to preheat medical waste,improve the temperature of medical waste,remove moisture while crushing garbage,and avoid wasting a lot of heat energy due to water evaporation in gasifier.Through the energy balance analysis of gasifier and combustor,the power consumption of plasma torch under different working conditions is calculated,and the energy saved by adding rotary preheater is calculated from the angle of water content.The results show that when the water content is 20%,30%,40%and 50%,the plasma torch will save about 27kw,41kw,55kw and 69kw power respectively.The greater the water content,the more energy saved by the preheating effect of rotary preheater,and the more obvious the energy saving effect.In this paper,various indexes of high temperature air gasification are obtained by comprehensive calculation method.The gasification efficiency is 78.9%,the gasification yield is 1.853 m3/kg,and the carbon conversion rate is 82.4%.The gasification indexes are higher than those of traditional gasification indexes.Preliminary cold and hot tests were carried out on the experimental system.The change of air side resistance at different air inlet flow rate was tested by cold state test.According to the results of cold state test,the corresponding improved design scheme was put forward for the experimental system.The heat transfer performance of regenerator under different reversing cycles,furnace temperatures and inlet flow rate of combustion-supporting air was studied by thermal experiments.The results show that the temperature efficiency of the extreme waste heat recovery technology is over 90%,the thermal efficiency is close to 80%,and the emission concentration of nitrogen oxides in flue gas is also lower than the national flue gas emission standard.