A Study on the Effects of Coolant Strategy on the Instantaneous Energy Balance During the Warm-up Period in a Spark Ignition Engine

Authors : Galip KALTAKKIRAN

Pages : 1-8

View : 13 | Download : 13

Publication Date : 2021-12-15

Article Type : Research Paper

Abstract :It is very important to examine the instantaneous effects of energy losses on each other in order to ensure high efficiency during the warm-up period in internal combustion engines. In this regard, the effects of energy losses can be examined and some improvements can be achieved with different thermal energy management strategies involving various electromechanical components. Two different thermal energy management strategies were implemented in this study under different operating conditions of the engine. These strategies comprise applications with mechanical and electrical water pump integrated cooling system components. In the configuration with a mechanical pump, the coolant is circulated in the engine block in proportion to the engine speed. Under the same operating conditions, the coolant flow rate was reduced to 50%, in the configuration with the electric water pump. The warm-up time of the engine, instantaneous change in the coolant flow rate and temperature during the warm-up period of the engine, instantaneous input fuel energy balance, and specific fuel consumption were investigated under all operating conditions. As a result, thanks to the electric pump strategy, the engine efficiency was observed to have improved and the total unaccounted energy loss to have reduced. Furthermore, engine warm-up time improved by 2.6% to 8.3% and the specific fuel consumption by 17.9% to 2.1%, respectively, under low and high load conditions. Thus, the coolant control strategy has been shown to have a significant effect on engine efficiency.
Keywords : Energy balance, Coolant flow rate, Warm up, Thermal energy management, SI engine