MONITOR ING OF STATE QUANTITIES OF DIESEL ENGINES IN LABORATOR Y CONDITIONS

Worsening of ecological parameters of an engine causes a pressure drop in the combustion chamber or declines the technical condition of the fuel system (H o f m a n n , R a u s c h e r , 1996). The present experiment describes the possibility of low pressure turbocharging at the atmospheric diesel engine and provides necessary information on the state quantity pressure at the end of the compression stroke. Contribution points out the effect of wear of functional pairs in combustion chamber and a subsequent decrease of the level of air internal energy at the end of the compression stroke. The observed diesel engine is atmospheric, so its low pressure supercharging can be ensured from a separate air tank. Simulation of the worn engine was secured by changing the exhaust valve’s clearance to 0.50 mm for comparison of the measured values, so the limit wear state reached 28%. The objectives of the experiment were fulfilled, and applied low-pressure supercharging has been proved. On the basis of the measured data, the detected value of the supercharging was just 40 kPa, while the pressure at the end of compression stroke of the simulated worn engine equaled to the pressure of the new engine at the selected speed.