Research On Power Generation System Using Coke Oven Gas And It's Running Management

At present, the energy efficiency in China is rather low, the unit energy consumption of most products is higher than that of developed countries. The heat value of waste gas discharging into environment accounts for more than 20% of the total energy consumption of industrial furnaces, the utilization rate of the waste gas is only 4% to 5%. Therefore, there is a big energy conservation potential. This dissertation is based on the project of the power generation using the remaining coke oven gas in Zi Xing Coke Electricity Limited Corporation, constructs a reasonable power generation system, and carries on the thermodynamic calculation on the gas internal combustion engine and the heat recoverer. It aims at reducing the energy consumption, increasing the economic efficiency, and discussing the best running management when the gas flowrate changes.The main contents and conclusions in this dissertation are followimg:(1) The best power generation scheme was chosen, and the types of the main facilities were selected. The selected type of the gas internal combustion engine is 500GF-RJ which is researched and developed by the Shengli Power and Machinery Engineering Limited Corporation. For matching the gas internal combustion engine, the type of the generator is 1FC6 406-4LA42-Z, and the waste heat recoverer produced by Qingdao Kaineng Limited Corporation is specialized in recycling the waste heat from the exhaust pipes. The system is composed of 14 engines and boilers, and has been put in practice by twice.(2) The monitoring and control system of the project were designed, and the principles of the control system were introduced.(3) The thermodynamic calculation of the gas internal combustion engine were performed by programming adopting C++language, and the efficiency curves was gained by Matlab. The electricity generation and the coke gas consumption was calculated when the work status of the gas internal combustion engine changes. The result shows that the effective power increases with the improvement of the rotating speed of the internal combustion engine. On the contrary, the effective gas consumption rate decreases with the improvement of the rotating speed. At the rated speed, it has a minimum gas consumption value, i.e.286.7g/kWh every engine. That is to say, in order to get a high effective power, the internal combustion engine should run at a high rotating speed as possible.(4) The heat exchange of the pin-tube boiler was completed by using the combined means of log-mean temperature difference and the number of heat transfer unit, which is used to recover the waste heat of flue ejected from the gas internal combustion engine. The steam outputs of the pin-tube heat boiler were gained, and the graph of steam outputs changing with the load of the internal combustion engine was drawed. The results show that the steam outputs increase with the improvement of the flue temperature and the load of the internal combustion engine. When the internal combustion engine runs at the full load, the steam output reachs a maximum value, that is 365.3kg/h every boiler.(5) The best number of the running units in different intake for coke oven gas was discussed, and the effect of gas charging on the economics of the system was analyzed. The reasonable scheme of running management of the system was proposed, and the economy of the system was evaluated.The research shows that, project of coke oven gas power generation in Zi Xing Coke Electricity Limited Corporation has good economy benefit. It can not only save energy and reduce the environment pollution, which accords with the energy-saving and environmental protection policy of the nation, but also can create economic benefit for the corporation. In addition, the result can provide a theoretical basis for the running management of the coke oven gas power generation system.