Passive Two-Phase Cooling of Automotive Power Electronics

Passive Two-Phase Cooling of Automotive Power Electronics
Author:
Publisher:
Total Pages: 10
Release: 2014
Genre:
ISBN:

Download Passive Two-Phase Cooling of Automotive Power Electronics Book in PDF, Epub and Kindle

Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated, and tests were conducted using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator design that incorporates features to improve performance and reduce size was conceived. Simulation results indicate its thermal resistance can be 37% to 48% lower than automotive dual side cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers--plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

Inverter-Scale, Passive Two-Phase Cooling System for Automotive Power Electronics

Inverter-Scale, Passive Two-Phase Cooling System for Automotive Power Electronics
Author:
Publisher:
Total Pages: 0
Release: 2014
Genre:
ISBN:

Download Inverter-Scale, Passive Two-Phase Cooling System for Automotive Power Electronics Book in PDF, Epub and Kindle

Reducing the cost, weight, and volume of automotive power electronic systems is necessary to increase electric-drive vehicle market penetration. These reductions can be achieved by improving power electronics thermal management to allow for greater power densities and lower operating temperatures.

A Two-phase Cooling Method Using R134a Refrigerant to Cool Power Electronics Devices

A Two-phase Cooling Method Using R134a Refrigerant to Cool Power Electronics Devices
Author:
Publisher:
Total Pages:
Release: 2004
Genre:
ISBN:

Download A Two-phase Cooling Method Using R134a Refrigerant to Cool Power Electronics Devices Book in PDF, Epub and Kindle

Power electronics are vital to the operation and performance of hybrid-electric vehicles (HEVs) because they provide the interface between the energy sources and the traction drive motor. As with any "real" system, power electronic devices have losses in the form of heat energy during normal switching operation, which has the potential ability to damage or destroy the device. Thus, to maintain reliability of the PE system, the heat energy produced must be removed. Present HEV cooling methods provide adequate cooling effects, but lack sufficient junction temperature control to maintain long-term reliability. This thesis is based on using the automobile's air conditioning system as an alternative to conventional power electronics cooling methods for hybrid-electric vehicle applications. This thesis describes the results from a series of experiments performed on a circuit containing an IGBT, gate controller card, and snubber while submerged in an automotive refrigerant bath (R134a). The circuit was then tested while being cooled using a mock automotive air conditioning system. Tests were performed on custom made thin-film resistors while being cooled by the same mock air conditioning system. The thin-film resistors were arranged to resemble a six-switch, three-phase inverter in steady-state operation. Lastly, an active IGBT junction cooling technique is described and simulated, which incorporates direct cooling of the junction of the power electronic device rather than its case. The results from the simulation indicate the exposed junction IGBT technique would benefit the device by reducing the junction temperature, increasing forward current ratings, and increasing reliability.

Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics Using Practical Enhanced Surfaces

Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics Using Practical Enhanced Surfaces
Author: Sulaiman Saleh Altalidi
Publisher:
Total Pages: 78
Release: 2017
Genre: Automobiles
ISBN:

Download Two-Phase Spray Cooling with HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics Using Practical Enhanced Surfaces Book in PDF, Epub and Kindle

The objective of this research was to investigate the performance of two-phase spray cooling with HFC-134a and HFO-1234yf refrigerants using practical enhanced heat transfer surfaces. Results of the study were expected to provide a quantitative spray cooling performance comparison with working fluids representing the current and next-generation mobile air conditioning refrigerants, and demonstrate the feasibility of this approach as an alternative active cooling technology for the thermal management of high heat flux power electronics (i.e., IGBTs) in electric-drive vehicles. Potential benefits of two-phase spray cooling include achieving more efficient and reliable operation, as well as compact and lightweight system design that would lead to cost reduction. The experimental work involved testing of four different enhanced boiling surfaces in comparison to a plain reference surface, using a commercial pressure-atomizing spray nozzle at a range of liquid flow rates for each refrigerant to determine the spray cooling performance with respect to heat transfer coefficient (HTC) and critical heat flux (CHF). The heater surfaces were prepared using dual-stage electroplating, brush coating, sanding, and particle blasting, all featuring "practical" room temperature processes that do not require specialized equipment. Based on the obtained results, HFC-134a provided a better heat transfer performance through higher HTC and CHF values compared to HFO-1234yf at all tested surfaces and flow rates. While majority of the tested surfaces provided comparable HTC and modestly higher CHF values compared to the reference surface, one of the enhanced surfaces offered significant heat transfer enhancement.