External speed characteristics of a diesel engine when operating on cooled fuel

Abstract

The results of research of the possibility of improving the performance of diesel engine D-243 (type 4Ch 11/12,5) designed for agricultural tractor at its operation on cooled fuel are presented. The research was carried out on a computer model. Two variants of the external velocity response of the diesel engine are calculated: at a typical fuel temperature in the injector atomizer equal to 380 K; and when the fuel is cooled to 303 K (30 °C). The crankshaft speed of the diesel engine varied from 1000 to 2200 min^–1. The effective power and the operating torque of the diesel engine when operating on cooled fuel were higher by 16.9–17.8%. This result is mainly due to the growth of hourly fuel consumption by 16.4–16.8%. Specific fuel consumption differs within ±1.9 g/(kWh), and at cooling with favorable result in the most demanded speed range: 1800÷2200 min^–1. The main thermodynamic parameter, the internal efficiency, changes by ±1.1% relative to the first variant, which indicates that the quality of the diesel working process is preserved. Smokiness on cooled fuel is higher and has an absolute difference of 1–10%. Emission of nitrogen oxides increases by 0.9–1.4 g/(kWh). Greenhouse gas emissions, on the contrary, decrease by 0–6 g/(kWh). Due to the forced cooling of the fuel supplied it is possible to significantly improve the traction and power properties of the D-243 diesel engine when working on the external speed characteristic in the period of spring-summer operation. Environmental indicators do not change significantly. One should expect an increase in the lubricity of modern low-sulfur diesel fuel when it is cooled and an increase in the reliability of the fuel system during the specified period of the tractor's operation. At the same time, the changes in the fuel system operation are the same as in case of natural fuel cooling in the fall-winter period of operation in the conditions of continental climate of Western Siberia and other regions. Regulating parameters of the fuel system remain unchanged.