Simulation based identification of the ideal defrost start time for a heat pump system for electric vehicles

Steiner, Alois; Rieberer, René

doi:10.1016/j.ijrefrig.2015.04.018

Cited by 28 publications

(7 citation statements)

References 10 publications

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“…Ahn et al also studied effective dehumidification by a heat pump with a dual-evaporator system in electric vehicles [109]. A research study by Steiner and Rieberer concluded that incorrectly chosen defrost starting time reduced the efficiency of the heat pump system significantly [110].…”

Section: State-of-the-art Technologies For Cabin Thermal Managementmentioning

confidence: 99%

“…Their research focused on improving the efficiency of a heat pump by recovering heat from the fuel cell stack exhaust with different heat exchanger arrangements. Steiner and Rieberer developed a transient model of a reversible heat pump system with CO2 refrigerant aiming at analyzing the influence of defrosting start time [110].…”

Section: State-of-the-art Technologies For Cabin Thermal Managementmentioning

confidence: 99%

“…Due to the need of reducing thermal energy consumption in electric vehicles, approaches that are more complete have been introduced [20], [139]. Steiner and Mladek introduced an occupant centered holistic approach for reducing energy consumption including technologies of energy harvesting with photovoltaic cells and shock absorbers, and preconditioned battery as heat source [110]. Because electrified vehicles do not have a lot of excessive heat for the cabin heating, zonal and local heating solutions can be considered well suitable for increasing the heating energy efficiency.…”

Section: Other Technologiesmentioning

confidence: 99%

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Review of Cabin Thermal Management for Electrified Passenger Vehicles

Lajunen

Yang

Emadi

2020

IEEE Trans. Veh. Technol.

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The technical maturity and rapidly increasing market share of electrified vehicles have given more importance to the cabin thermal management. Efficient thermal management has a key role to maintain adequate electric operating range, protect components from aging and ensure passenger comfort. This research comprehensively reviews the cabin thermal management systems for electrified vehicles. Various vehicle cabin thermal modeling techniques and the key concepts for cabin thermal comfort have been discussed. Different technical and operational solutions of the cabin thermal management in hot and cold climate conditions are evaluated. The recent developments including heat pumps, thermal system control, passive thermal management, and cabin preconditioning to increase thermal management efficiency are analyzed. The results show that increasing amount of research is focusing on improving the thermal efficiency of the individual electrical components and the vehicle level systems. However, new solutions will be required for reducing the cabin thermal load under hot conditions and improving the heating system operational flexibility and efficiency in cold climates.

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Section: State-of-the-art Technologies For Cabin Thermal Managementmentioning

confidence: 99%

Section: State-of-the-art Technologies For Cabin Thermal Managementmentioning

confidence: 99%

Section: Other Technologiesmentioning

confidence: 99%

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Review of Cabin Thermal Management for Electrified Passenger Vehicles

Lajunen

Yang

Emadi

2020

IEEE Trans. Veh. Technol.

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“…Microfiber heating blankets, graphene-based heating bedding, and flexible flat heating elements based on stainless steel metal fiber electrodes are commercially available, and the application range of this technology continues to expand. However, warm clothing with full thermostatic properties at specific temperatures has not yet been reported [ 21 , 22 , 23 , 24 , 25 , 26 ]. A heating element without PTC characteristics relies on a thermostat or electronic circuit to control the applied power, but these components can be associated with discomfort during wearing or activity, performance degradation after washing, and burn or fire risks due to abnormal heat generation.…”

Section: Introductionmentioning

confidence: 99%

Properties of Surface Heating Textile for Functional Warm Clothing Based on a Composite Heating Element with a Positive Temperature Coefficient

Choi

Jee²,

et al. 2021

Nanomaterials

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A high-stretch positive temperature coefficient (PTC) surface heating textile (PTC-SHT) was fabricated using a composite of PTC powder and multiwall carbon nanotubes (MWCNTs). The PTC-SHT (heating area = 100 × 100 mm2) was produced by screen-printing the PTC-MWCNT composite paste onto a high-stretch textile with embroidered electrodes. Overall, the temperature increased to 56.1 °C with a power consumption of 5 W over 7 min. Subsequently, the surface temperature of the PTC-SHT remained constant despite the continued decrease in power consumption. This indicated that heating was accompanied by an increase in resistance of the PTC-SHT, which is typical of this process—i.e., heating to a constant temperature under a constant voltage over an extended period of time. In addition, 4.63 W power was required to heat the PTC-SHT surface from an external temperature of 5 to 45 °C in 10 min, after which stable low-temperature heat generation behavior was observed at a constant temperature of 50 °C, which was maintained over 40 min. In contrast, negative temperature coefficient (NTC) behavior has been observed in an NTC-SHT consisting of only MWCNTs, where a slow heating rate in the initial stage of power application and a continuous increase in surface temperature and power consumption were noted. The PTC-SHT consumed less power for heat generation than the NTC-SHT and exhibited rapid heating behavior in the initial stage of power application. The heat generation characteristics of the PTC-SHT were maintained at 95% after 100,000 cycles of 20% stretch–contraction testing, and the heating temperature remained uniformly distributed within ± 2 °C across the entire heating element. These findings demonstrated that an SHT with PTC characteristics is highly suitable for functional warm clothing applications that require low power consumption, rapid heating, stable warmth, and high durability.

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“…14 of the 19 tests developed in cooling mode. Only the testing conditions with condenser air supply temperature higher than 35ºC are considered in this table.…”

mentioning

confidence: 99%

Experimental characterization of a reversible heat pump for hybrid and electric vehicles

Cuevas

Declaye

Lemort

2019

Advances in Mechanical Engineering

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The most performant system for heating in electric and hybrid vehicles is the heat pump. This study proposes a heating system with a reversible heat pump, which works as a conventional air conditioning system in cooling mode and in heating mode it uses a secondary circuit with water/glycol to transfer the heat from the condenser to the heater core located in the air conditioning module. This system was experimentally validated with 61 tests in heating mode and 19 tests in cooling mode. In the heating mode, there is a test which was developed with an ambient temperature of -1ºC with the air circulating through the outdoor unit at a velocity of 3.2 mÁs 21 , an air flow rate of 388 kgÁh 21 supplied to the cabin and the compressor running at 2866 r/min. At these conditions, the air is supplied to the cabin at 41.5ºC, the heating power is 4.2 kW and the COP is 1.9. In the cooling mode, there are tests developed at a condenser supply air temperature of 45.4ºC with a velocity of 5.7 mÁs 21 . The air is supplied to the vehicle cabin with a temperature of 14.6ºC with a flow rate of 508 kgÁh 21 , with a cooling capacity of 3.88 kW and a coefficient of performance of 1.8.

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Simulation based identification of the ideal defrost start time for a heat pump system for electric vehicles

Cited by 28 publications

References 10 publications

Review of Cabin Thermal Management for Electrified Passenger Vehicles

Review of Cabin Thermal Management for Electrified Passenger Vehicles

Properties of Surface Heating Textile for Functional Warm Clothing Based on a Composite Heating Element with a Positive Temperature Coefficient

Experimental characterization of a reversible heat pump for hybrid and electric vehicles

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