Application of Intermediate Vapor Bypass to Mobile Heat Pump System: Extending Operating Range to Lower Ambient Temperature with Low Pressure Low GWP Fluid

Research output: Contribution to journalConference article

Abstract

With market share of electric vehicles continue to grow, there is an increasing demand of mobile heat pump for cabin climate control, as it has much higher energy efficiency when compared to electric heating and helps to cut drive range reduction. One big challenge of heat pump systems is that their heating capacities drop significantly when operating at very low ambient temperature, especially for those with low pressure refrigerants. This paper presents a way to improve low ambient temperature heating performance by using intermediate vapor bypass with the outdoor heat exchanger, which works as an evaporator in heat pump mode. The experimental results show a 35% increase of heating capacity at 20 °C ambient with the improved system as compared to the baseline, and heating performance factor also slightly increased when the system is working at higher ambient temperature to reach the same heating capacity as the baseline. Further improvement of system design and heat exchanger optimization is underway.

Original languageEnglish (US)
JournalSAE Technical Papers
Volume2018-April
DOIs
StatePublished - Jan 1 2018
Event2018 SAE World Congress Experience, WCX 2018 - Detroit, United States
Duration: Apr 10 2018Apr 12 2018

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Heat pump systems
Vapors
Heating
Fluids
Heat exchangers
Temperature
Pumps
Climate control
Electric heating
Refrigerants
Evaporators
Electric vehicles
Energy efficiency
Systems analysis

ASJC Scopus subject areas

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering

Cite this

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title = "Application of Intermediate Vapor Bypass to Mobile Heat Pump System: Extending Operating Range to Lower Ambient Temperature with Low Pressure Low GWP Fluid",
abstract = "With market share of electric vehicles continue to grow, there is an increasing demand of mobile heat pump for cabin climate control, as it has much higher energy efficiency when compared to electric heating and helps to cut drive range reduction. One big challenge of heat pump systems is that their heating capacities drop significantly when operating at very low ambient temperature, especially for those with low pressure refrigerants. This paper presents a way to improve low ambient temperature heating performance by using intermediate vapor bypass with the outdoor heat exchanger, which works as an evaporator in heat pump mode. The experimental results show a 35{\%} increase of heating capacity at 20 °C ambient with the improved system as compared to the baseline, and heating performance factor also slightly increased when the system is working at higher ambient temperature to reach the same heating capacity as the baseline. Further improvement of system design and heat exchanger optimization is underway.",
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