ENGINE COOLING SYSTEM
By
PUNEET SAXENA
NEW HOLLAND, INDIA
Object of the Paper : To analyse the cooling system of the engine in order to achieve the optimum
performance for efficient working of engine.
ABSTRACT
This paper explores the technical aspects involved in the designing of the cooling systems for the tractor.
The heat carried by the cooling water jacket is 30% of the total energy produced in the engine. A small but
significant percentage of the power is being consumed by the fan and the pump, which should be
judiciously, combined with the suitable radiator to achieve not only the efficient performance of the engine
but also the cost effectiveness.
In tractors usually the air cooled radiators work in association with the fan which must provide the airflow
requirements of the cooling system against the pressure loss, operate effectively and quietly and while
being fitted in allocated space. These parameters must be considered to satisfy the requirement of airflow,
fan diameter and fan speed. The purpose of this paper is to apply the available data efficiently towards the
solution of the problem. By applying the Angular Momentum Equation to a fixed control volume the inlet
and outlet velocity polygons are developed to achieve the power consumed by the fan along with the
resulted volume flow rate.
Radiators are heat exchangers provided to help control engine operating temperatures. Operating fluids are
engine coolant on the inside and ambient air on the outside. In the radiator system out of engine coolant and
air, air is the minimum fluid. The critical parameter for tractors is the Air-to-Boil Temperature (ATB)
which determines the selection of the radiator in tractors. The engine power determines the heat exchange
required from the specific radiator. Further the parameters – Mixed or Unmixed flow, Boiling Temp.,
Ambient Temp., ATB and the Air inlet temp. are used to determine the Overall Heat Transfer Coefficient
to the corresponding volume flow rate of the air. The selection is made for the proper combination of the
volume flow rate (affecting the power consumed by the fan) and the overall heat transfer coefficient
(determining the cost of the radiator). The water flow rate is being used to calculate the effectiveness of the
radiator. Hence the combination of the Engine Horse Power along with the Water Flow Rate and Volume
Flow Rate from fan can be used to get the effective cooling. The radiator is being tested for ATB on the
tractor both at the rated and peak torque.
This study is being used to build the software program for determining the Radiator and Fan specification
for the effective cooling in the tractor.