Experimental study on the heat balance of turbocharged marine diesel engines with variable coolant flow

ABSTRACT

An engine heat balance experiment was conducted to analyse the influence of the freshwater pump speed on the overall performance of the diesel engine. At low and medium loads, appropriately reducing the coolant flow could reduce the fuel consumption rate and improve the effective power. At the rated load, when the pump speed was 2000 r/min, the diesel power and fuel economy were optimal. Under overload conditions, appropriately increasing the coolant flow could improve the fuel economy. The zone between the two exhaust valves of the cylinder head (Point C) had the highest thermal load. At medium loads—when the pump speed was 1600 r/min—the Point C temperature was close to the creep temperature. At rated and overload loads—when the pump speed was less than 2200 r/min—the Point C temperature entered the creep temperature range. The experimental results provided a theoretical basis for intelligent cooling control strategies..

KEYWORDS:

• Variable coolant flow
• marine diesel engine
• thermal load
• piston and cylinder head
• heat balance
• fuel consumption rate

Acknowledgements

This work was supported by the Chinese Hubei Province Natural Science Foundation (Grant number 2016CFB62) and the Chinese ‘13th Five-Year’ Advance Research Programme Foundation (Grant number 3020401030403). The authors gratefully acknowledge the Henan Diesel Engine Industry Co., Ltd (HND) for supplying the required data and experimental platform for the engine and cooperation in implementing the experiments.

Disclosure statement

No potential conflict of interest was reported by the author(s).