1. Steam Power Generation: Based on the evaporation capacity and other parameters of the waste heat boiler, a screw expander or steam turbine generator set can be selected. In this way, the steam generated by the waste heat boiler not only meets the production and living needs of the treatment center, but any excess steam is used to generate electricity through the screw expander or steam turbine generator set. The annual operating hours of the screw expander or steam turbine generator set match those of the incineration system, eliminating steam exhaust and fully utilizing the incineration system to incinerate the flue gas waste heat. While this method ensures full and effective utilization of the flue gas waste heat, it requires significant investment, requires significant floor space, and is complex. Therefore, if the project is constrained by investment and land, this method may be difficult to implement.
2. Comprehensive Utilization: For small-scale hazardous waste incineration projects where steam power generation is unavailable, comprehensive utilization of the flue gas waste heat should be considered. First, consider preheating the air used to support combustion in the incineration system. The advantages of using hot air to assist combustion in incineration systems are significant. First, it improves combustion. Preheating the combustion air accelerates the combustion process, which is particularly important for auxiliary fuels, especially waste oil. Preheating the combustion air accelerates the vaporization of atomized oil droplets, improving ignition conditions and increasing the combustion reaction rate. This allows for complete combustion with a lower excess air ratio, reducing the processing capacity of the subsequent flue gas purification system. Second, it directly reduces fuel consumption. Increasing the combustion air temperature by 100°C can directly reduce the fuel rate by 4%-5%. Preheating the combustion air to 200-300°C is recommended, which can directly reduce fuel consumption by 8%-15%. Because the flue gas generated by hazardous waste incineration can reach temperatures as high as 1100°C and release a significant amount of heat, preheating the combustion air alone can only partially recover the waste heat. Therefore, a waste heat boiler is also required to recover excess flue gas heat in the form of steam. When designing a specific waste heat recovery and utilization plan, the unique characteristics of the flue gas generated by hazardous waste incineration should be carefully considered. If the high-temperature flue gas is directly used to preheat the combustion air in an air preheater, the problems of excessive wall temperatures and excessive smoke must be carefully addressed. If the incineration flue gas first enters a waste heat boiler, where it recovers most of the waste heat as steam and settles most of the smoke, this creates optimal operating conditions for the subsequent air preheater. Therefore, the design sequence is for the incineration flue gas to first pass through the waste heat boiler and then enter the air preheater. In summary, due to the remote location of the disposal project, there are few other potential steam users. Therefore, steam utilization is primarily focused on internal use. However, in addition to power generation, the author believes that utilizing waste heat for central air conditioning is another promising avenue. This involves converting waste heat into energy and supplying it to absorption chillers, thus achieving central air conditioning in integrated management areas. The main parameters of steam-type chillers are shown in Table 1. Taking a 1160kW refrigeration unit as an example, the key performance indicators of steam-type refrigeration and air conditioning are compared with those of conventional electric refrigeration and air conditioning units in Table 2. As can be seen from Table 2, the power consumption of the steam-type refrigeration air-conditioning main unit is only 2.33% of that of electric refrigeration, and the system power consumption is only 36.5% of that of electric refrigeration, which can greatly reduce operating costs. At the same time, steam-type refrigeration air-conditioning is a mature technology. It can be put into operation once installed. It is simple to operate, stable, and has a low failure rate, and can be widely used.
1. Steam Power Generation: Based on the evaporation capacity and other parameters of the waste heat boiler, a screw expander or steam turbine generator set can be selected. In this way, the steam generated by the waste heat boiler not only meets the production and living needs of the treatment center, but any excess steam is used to generate electricity through the screw expander or steam turbine generator set. The annual operating hours of the screw expander or steam turbine generator set match those of the incineration system, eliminating steam exhaust and fully utilizing the incineration system to incinerate the flue gas waste heat. While this method ensures full and effective utilization of the flue gas waste heat, it requires significant investment, requires significant floor space, and is complex. Therefore, if the project is constrained by investment and land, this method may be difficult to implement.
2. Comprehensive Utilization: For small-scale hazardous waste incineration projects where steam power generation is unavailable, comprehensive utilization of the flue gas waste heat should be considered. First, consider preheating the air used to support combustion in the incineration system. The advantages of using hot air to assist combustion in incineration systems are significant. First, it improves combustion. Preheating the combustion air accelerates the combustion process, which is particularly important for auxiliary fuels, especially waste oil. Preheating the combustion air accelerates the vaporization of atomized oil droplets, improving ignition conditions and increasing the combustion reaction rate. This allows for complete combustion with a lower excess air ratio, reducing the processing capacity of the subsequent flue gas purification system. Second, it directly reduces fuel consumption. Increasing the combustion air temperature by 100°C can directly reduce the fuel rate by 4%-5%. Preheating the combustion air to 200-300°C is recommended, which can directly reduce fuel consumption by 8%-15%. Because the flue gas generated by hazardous waste incineration can reach temperatures as high as 1100°C and release a significant amount of heat, preheating the combustion air alone can only partially recover the waste heat. Therefore, a waste heat boiler is also required to recover excess flue gas heat in the form of steam. When designing a specific waste heat recovery and utilization plan, the unique characteristics of the flue gas generated by hazardous waste incineration should be carefully considered. If the high-temperature flue gas is directly used to preheat the combustion air in an air preheater, the problems of excessive wall temperatures and excessive smoke must be carefully addressed. If the incineration flue gas first enters a waste heat boiler, where it recovers most of the waste heat as steam and settles most of the smoke, this creates optimal operating conditions for the subsequent air preheater. Therefore, the design sequence is for the incineration flue gas to first pass through the waste heat boiler and then enter the air preheater. In summary, due to the remote location of the disposal project, there are few other potential steam users. Therefore, steam utilization is primarily focused on internal use. However, in addition to power generation, the author believes that utilizing waste heat for central air conditioning is another promising avenue. This involves converting waste heat into energy and supplying it to absorption chillers, thus achieving central air conditioning in integrated management areas. The main parameters of steam-type chillers are shown in Table 1. Taking a 1160kW refrigeration unit as an example, the key performance indicators of steam-type refrigeration and air conditioning are compared with those of conventional electric refrigeration and air conditioning units in Table 2. As can be seen from Table 2, the power consumption of the steam-type refrigeration air-conditioning main unit is only 2.33% of that of electric refrigeration, and the system power consumption is only 36.5% of that of electric refrigeration, which can greatly reduce operating costs. At the same time, steam-type refrigeration air-conditioning is a mature technology. It can be put into operation once installed. It is simple to operate, stable, and has a low failure rate, and can be widely used.