Research Of The Intelligent Exhausting Temperature Measurement Device For Ship Diesel Engine Based On Genetic Algorithm

The diesel engine air cylinder discharge temperature is a key parameter which must be monitored during the operation of diesel engine. The reason of ship diesel engine's hyperpyrexia is the fuel's second combustion in the exhaust pipe caused by its imperfect combustion in the air cylinder. The hyperpyrexia of ships diesel engine affects its normal work, such as distorting and breaking the exhaust pipe to leak air and becoming a hidden fire danger, simultaneously it also pollutes the engine room and influences staff's normal work; The hyperpyrexia also causes the cavitations damage between engine piston and air cylinder and drops the rev of supercharger, then drops the charging coefficient, making it not in gear.Combining the traditional thermo-element temperature measurement technology, the genetic algorithm technology and the monolithic integrated circuit technology, this paper designs a digital intelligent temperature measurement device which can calibrate automatically and the manually and can be read directly and accurately. Adopting monolithic integrated circuit chip AT89C52 as the microprocessor, and thermoelement as the temperature sensor, this device can measure and demonstrate the 12 diesel engine cylinder's exhaust temperatures correctly, and alarm the ultra temperature.This thesis is composed by three parts: the establishment of the thermoelement mathematical model, the hardware design of the intelligent temperature measurement device and the software design of the intelligent temperature measurement device. The first part analyzes the elementary knowledge of thermoelement and the genetic algorithm, designs the thermoelement signal recuperation electric circuit, and uses AD590 to solve the thermo-element cold end compensation problem. At the same time, it establishes a mathematical model based on the genetic algorithm, and solves the non-linear problem of the K thermoelement (nichrome - nickel silicon). The second part of the thesis designs the hardware and the electric circuit of the intelligent temperature measurement device. This intelligent temperature measurement device is composed of five main parts: The temperature measurement electric circuit, a/d conversion, the power source, the keyboard entry and the nixietube demonstration. It also introduces each part's main chip, and designs its interface circuit.The third part designs the software of the intelligent temperature measurement device, introduces procedure compilation tool KeilC51, and takes modular the programming method, compiles suitable thermo-element temperature measurement procedure for monolithic integrated circuit, solves the non-linear problem between the thermoelement thermoelectric force and the temperature, reduces the temperature measurement error brought by the thermo-element oxidation, and accomplishes all the functions this intelligent temperature measurement device needed.