Studies On Design And Operating Characteristics Of Gas Turbine And Tunnel Kiln Integrated System

When the tunnel kiln system works,the chemical energy of natural gas is transformed into heat energy.After burning natural gas,high temperature gas is sprayed into the kiln for firing ceramics.There are specific requirements for the temperature system in kiln of tunnel kiln.Generally,the sintering temperature of ceramic is about 1,200 degrees Celsius.The highest temperature of the gas in the kiln is about 1,400 degrees Celsius.If the excess air coefficient is 1,the natural gas theory burns at 2,000 degrees Celsius.Actually,a large amount of excess air is added to the combustion chamber to reduce the combustion temperature.If the excess air coefficient is above 1.58,the theoretical combustion temperature is 1400 degrees Celsius.The smoke containing a large amount of excess air is emitted into the environment.The loss of exhaust smoke of the system is too high and the utilization rate of heat is too low,which leads to huge waste of gas energy.The problem of high energy consumption and low thermal efficiency of traditional tunnel kiln system is a major problem in ceramic production industry.As a kind of high quality fuel energy,natural gas is converted into low quality heat energy in tunnel kiln,and the efficiency of energy utilization is very low.This is an urgent problem to be solved at present.After the second combustion,the heat is supplied to the kiln for firing ceramic products.The energy saving analysis of traditional tunnel kiln is showed in this paper.The effect of excess air coefficient on heat loss of traditional tunnel kiln was studied.The results show that the heat loss rate of the traditional tunnel kiln is up to 19.66%.To reduce the excess air coefficient of the flue gas from the kiln,the integrated system of gas turbine and tunnel kiln is proposed.The energy saving analysis of the integrated system is carried out.The integrated system reduces the oxygen content of the flue gas from the kiln because of two combustion reactions of natural gas.After the first combustion reaction,heat energy is transformed into mechanical energy and electrical energy.Electric energy can be used in factories.The integrated system has realized the cascade utilization of energy.Some of the natural gas is used to generate high quality electrical energy,which improves the energy utilization quality of natural gas and improves the efficiency of energy utilization of the systemThermodynamic mathematical model of the traditional tunnel kiln system is established.The thermal calculation method of traditional tunnel kiln is put forward.The simulation results provide datas for the design of gas turbine and tunnel kiln integrated system.The form of gas turbine and tunnel kiln integrated system was designed.The calculation method of gas turbine and tunnel kiln integrated system is put forward.The energy consumption of integrated system is analyzed.The influence of pressure ratio and excess air coefficient on the performance of the integrated system is analyzed by using the system thermal efficiency and generation efficiency as the objective function.The results show that increasing the pressure ratio and reducing the excess air coefficient can improve the thermal efficiency of the integrated system.The power generation efficiency of the integrated system is independent of them.The economic analysis of the integrated system is completed in this paper,which provides technical support for the popularization of the system.The calculation and analysis of 72-meter-calcined sanitary ceramics tunnel kiln were carried out.The traditional tunnel kiln operation parameters were obtained,which consumed 66.62 cubic meters of natural gas per hour.In the form of integrated system,86.06 cubic meters of natural gas is consumed per hour,and 169 degrees of electricity is generated per hour.The thermal utilization ratio of the integrated system can be increased to over 23%,which is about 15% higher than the thermal utilization rate of traditional tunnel kiln system.Compared with a single gas turbine system,the efficiency of the integrated system can be 87%,which is more than 45% higher than that of a single gas generator.The economic analysis results show the investment recovery period of the integrated system is less than one year.