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Analysis the power of mechanical losses of ICE and
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| Analysis the power of mechanical losses of ICE and
methods of its determination. Power of mechanical losses of piston internal combustion engine is an indicator of its braking properties, it is composed of the following main components: M T P A N N N N (1) here T N – power of friction loss; P N – pumping power losses. The power of pumping losses, which is spent to suction into the cylinder and then to push gases out of it; A N – power loss on auxiliary mechanisms drive. These include: liquid, oil and fuel pumps, generator, interrupter-distributor, fan, etc. The results of the study of power components of mechanical losses of the diesel engine 4CH 10.5/12 at nominal operation mode at a speed of 2000 rpm are given in Table 1. 35 Table 2 – Power of components of mechanical losses of a diesel engine 4CH 10.5/12 Items Absolute value of mechanical losses. kW Relative value of mechanical losses. % Cylinder-piston group 6.5 39 Crank-rod mechanism 4.1 24 Pumping losses 2.4 14 Gas distribution mechanism 1.8 11 Pumps (oil + fuel) 1.5 9 Ventilator+generator 0.5 3 General 16.8 100 Analysis of the table data shows that the main losses occur in the cylinder piston group and the crank-rod mechanism. The results of comparative tests of diesel 4CH 10.5/12 and gasoline engine ZMZ-402.10 in the form of absolute values of mechanical losses for various components are presented in Figure 1 [2]. Figure 1 – Power distribution of mechanical losses on the basic parts and units of an IC engine: 1 – losses in cylindrical piston group; 2 – losses in the crank-rod mechanism; 3 – pump losses due to gas exchange; 4 – losses in the gas distribution mechanism; 5 – losses in auxiliary units 36 Comparison of distribution of components of mechanical losses on nodes and units of gasoline and diesel engines (Figure 1) shows that they differ insignificantly, and at a diesel engine loss in the cylindrical piston group and the crank-rod mechanism are slightly higher, and pump losses and losses of the gas distribution mechanism are slightly lower. This is due to the fact that the diesel engine has a much higher degree of compression. The power of mechanical losses of an internal combustion engine depends on the speed of its shaft. It is determined on the stand, both on the running motor and in the forced no-load mode [3][4]. Various methods are used for this purpose: 1. pressure indication in ICE cylinders; 2. by sequential disconnection of cylinders; 3. extrapolation of loading characteristic; 4. run-out methods; 5. forced scrolling of the combustion engine crankshaft. жүктеу/скачать 6,6 Mb. Достарыңызбен бөлісу:
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