This project describes the process of improving the engine oil cooler performance for future vehicle applications, from ideas to simulated concepts. Increasing market expectations of high engine power, low fuel consumption and high towing capabilities results in an ever rising pressure on the cooling system in modern cars.
The desire to prevent a future situation where the engine oil could become too hot, formed the basis for this thesis. The thesis was performed during 10 weeks from March to June 2015, at Volvo Car Corporation in Gothenburg.
The working process started with literary studies where the theory behind automotive cooling systems and heat exchangers were studied to increase the general knowledge about the theory. Studies of engine oil, heat transfer and the overall design of engine cooling systems were performed.
An important part was to clarify why the oil must not exceed a certain temperature limit. This gave answers to how the oil and engine components would be affected, if the oil did exceed the set temperature limit.
To get a clear target and measurable parameters, the goal of this thesis was defined by estimating what the heat transfer demands could be in the future. A competitor analysis was made to examine how and if, the competitors to VCC use a different kind of oil cooling. Generation of concept ideas were made continuously during the early stage of the work process. Concepts that proved to be interesting were analysed more deeply with performance simulations and packaging studies.
Five concepts were analysed and the performance simulations indicated that all the presented concepts can reach the heat transfer goal set early in the process. They do however use different methods, and meet the goal with different levels of efficiency. All concepts are listed with their heat transfer performance results and their advantages and disadvantages.
The concept that showed to be the most promising in an oil cooling perspective, was to connect an additional heat exchanger in series after the current plate heat exchanger. This is a solution which will support the current engine oil cooler by handling the additional heat produced during certain driving scenarios.
The best concept reached a heat transfer rate of 40 kW at half the air flow required by the second best concept. The concepts that has been presented will implicate an alteration of the current oil cooling system design. The lack of available space in the cars will also result in some rearranging of components in order to make space for an additional heat exchanger.
Source: Uppsala University
Authors: Hjälm Wallborg, Martin | Palmgren, Joakim