Abstract
Research and/or Engineering Questions/Objective
Extension of EV cruising range is an important requirement for increasing mainstream usage of EV. Air Conditioner power consumption is one of the major contributors to the decrease in EV cruising range. The objective of this study is to reduce air conditioner power consumption in order to increase EV crusing range, as well for actual fuel consumption improvement of all vehicles. ECS (Ejector Cycle System) STEP1 has already been developed and released in the market for automotive air conditioner systems in 2009. This paper will report on advanced ECS STEP2.
Methodology
Ejectors are already known as fluid jet pumps which can recover the expansion energy loss, that conventional expansion valve systems cannot recover. A new refrigeration system with highly efficient ejector has been successfully developed for automotive air conditioner systems. The high efficiency has been achieved through the development of ARC (Active flow Ratio Control), which is a vapor-liquid partition by swirl flow, a highly efficient ejector shape, and system optimization. ECS STEP2 has been achieved at the same level of simplification as ECS STEP1 by integrating ARC and the new ejector into an evaporator.
Results
The new ejector system ECS STEP2 achieves high energy recovery and dramatically reduces annual automotive air conditioner power consumption by 10 percent from ECS STEP1 and by 20 percent from conventional expansion valve systems.
Limitations of this study
The ejectors in this study are optimized for automotive air conditioner systems and their respective refrigerant. However, there is already the potential for other ejector applications, for example; water heater systems, vending machine systems, and automotive freezer systems. This technology can be applied to many kinds of refrigeration systems by optimization of the ejector shape for each application.
What does the paper offer that is new in the field including in comparison to other work by the authors?
This paper outlines the first introduction of ECS STEP2, which includes the new highly efficient ejector and a novel system configuration with ARC, in an automotive air conditioner system.
Conclusions
A highly efficient ejector refrigeration system, ECS STEP2, has been developed. It achieves 20 percent annual energy saving compared to conventional expansion valve systems. By this method, EV cruising range can be greatly increased.
Key Words : Automotive Air Conditioner, Air Conditioner Power Consumption, Ejector