The Inside Story on Thermal Management

March 1, 2020

Travis Mueller, Design Engineer for TLX Technologies

TLX Technologies designs and manufactures custom electro-mechanical solenoid products for the automotive industry. In this Q&A piece, Travis Mueller, Design Engineer for TLX Technologies, discusses the importance of thermal management in today’s vehicle designs.

Why is thermal management a critical concern in vehicle design today?

The quality of a thermal management system is directly related to the vehicle’s efficiency. Whether the vehicle has an internal combustion engine or is electrically powered, heat is always a by-product of the vehicle’s primary function—converting stored energy into motion. Since heat is a form of energy, any heat lost to the environment during the conversion process is considered a loss and is deducted from the efficiency of the system. A well-crafted thermal management system collects this excess heat energy and transfers it to another area of the vehicle that can use it for another purpose, increasing the overall efficiency of the vehicle.

How do internal combustion, hybrid and electric vehicles differ in their use of thermal management systems?

Internal combustion vehicles use thermal management to cool the engine, transmission and other mechanical systems throughout the vehicle. Hybrid vehicles use electronic, valve-controlled cooling systems, as well as traditional internal combustion cooling strategies. Electric vehicles have more systems that require precise thermal management (such as batteries and control electronics) than both internal combustion and hybrid vehicles. Each of these vehicle types has a different temperature requirement that must be maintained in order to operate efficiently.

How can OEMs increase the value of their thermal management system?

OEM’s can increase the value of their thermal management system by using customized designs that are specific to their application requirements. Custom designs ensure that the system is operating at its greatest efficiency and is not over- or under-engineered. OEM’s can also incorporate system valve requirements early in the design process to identify possible challenges and allow the engineer more freedom in the design without overconstraining the system.

What effect does flow rate have on thermal management efficiency?

Flow rate allows for better temperature control of a system. If one system needs to heat up quickly to function properly, it will need a large flow rate to transfer excess heat from other systems to this system. However, once the system reaches its optimal temperature, it needs to maintain this temperature to reach its maximum potential. Through precise flow control, the system can maintain a near constant temperature, allowing it to operate at maximum efficiency.

What are the key considerations that engineers should review as they start their next thermal management project?

Engineers should review flow rate and pressure drop requirements of their application. This will help to determine the optimal package size for the design and can reduce material cost and overall weight. Engineers should also review the system’s power consumption specifications. This will affect the size of the design and is crucial in electric vehicle applications that require high efficiency. When considering materials for the thermal management design, engineers should review the leakage specification and any agency ratings associated with the valve they plan to use. Lastly, engineers should review the duty cycle and control strategy of their thermal management system.

What is TLX Technologies doing in the thermal management space today?

TLX Technologies has developed different technologies for high flow and low flow coolant applications. Typically, when discussing solenoid valves, binary and proportional are the two options. However, TLX has added a third type of valve we call the discrete proportional valve. This kind of technology can provide a cooling system with stepped proportional control allowing it to achieve zero hysteresis, low pressure drop, and great energy efficiency. Past and current projects include proportionally redirecting coolant, managing urea temperature control, and utilizing latching technology in valves to increase efficiency. These technologies have been developed and used in internal combustion, hybrid and electric vehicle applications.