Performance Curves of I.C Engines
- The engine speed of an engine is maintained constant with the help of governor and the load on the engine is varied. The variation of indicated thermal efficiency, mechanical efficiency and brake specific fuel consumption Vs percentage of load on the engine is shown in Figure A, B and C respectively.
- It could be observed from performance curves of diesel engines that with increase in load the specific fuel consumption first decreases and then increases but the variation is not large and opposite is the case with regard to its thermal efficiency.
Log Sheet :
A log sheet is an half hourly record of the data with regard to the performance of each unit of plant. Log sheet includes the following data.
- Magnitude of voltage and current in each phase.
- Power produced in kW.
- Temperature and pressures of both cooling water and oil at inlet and outlet.
- Fuel consumption/hr.
- Air flow in m3/hr.
- Surrounding temperature and exit temperature of flue gases.
The data recorded on these log sheets enables the personnel to check whether the plant is working satisfactorily or not. It also helps to evaluate the performance of the plant.