• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.10
• /
• pp.4308-4313
• /
• 2011

The objective of this study is to investigate the cooling performance of the roof mounted air-conditioning system using electric driven scroll compressor for zero emission vehicles. This air conditioner with air source was used R-134a as a refrigerant and tested under various operating conditions such as refrigerant charge amount and indoor temperature, and compressor frequencies. Experimental results revealed that at all tested compressor frequencies, heat transfer rate of the evaporator increased and the cooling COP increased with the indoor temperature. In addition, the heat transfer rate of the evaporator was over 25.0kW sufficient for the cooling loads of an electric bus.

• Journal of Magnetics
• /
• v.19 no.3
• /
• pp.282-290
• /
• 2014

This paper discusses the development of a 3.5 kW switched reluctance motor (SRM)-based electric air-conditioning (AC) compressor, focusing primarily on the design aspects of the SRM and the integrated controller. In addition to the increased price of rare-earth magnets, SRM's operation capability at high speed and high temperature makes the SRM a viable alternative to the permanent magnet motor for electrically driven automotive air conditioning compressors. A compact and energy efficient scroll compressor is designed and constructed. Two feasible SRM topologies are considered, in terms of efficiency, torque ripple, and acoustic noise. Compact drive electronics are designed and employed to drive the SRM-based compressor. The static and dynamic performance is validated by simulation and experiment.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.1095-1100
• /
• 2006

An experimental study has been performed to investigate the correlation on compressor discharge temperature of system A/C in heating mode. Indoor and outdoor temperatures, the heating capacity, compressor discharge temperature and loading time are measured by the psychrometric calorimeter. The system is controlled by applying the scroll compressor, which Is operated by PWM valve and loading duty. With increasing outdoor temperature, the heating capacity increases, With increasing indoor temperature, it decreases. Also, with increasing loading duty the heating capacity increases. According to the increase in outdoor temperature and loading duty, compressor discharge temperature increases. From these experimental data, the correlation on compressor discharge temperature is proposed. It is expressed as a function of indoor temperature, outdoor temperature, and loading duty. The correlation obtained from the present study is agreed with the experimental data within $2^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.5
• /
• pp.531-538
• /
• 2013

The primary function of centrifugal compressor volute is to flow from the impeller and diffuser to the pipe system. The strength of the scroll vortex and flow pattern in the volute vary with the operating point. This is largely caused by the interaction between the impeller and the volute flow fields. The recirculation flow around the tongue and the scroll vortex can be used to understand the characteristics of the volute flow at off-design points. The present study aims to find the characteristics of a flow pattern in the diffuser and volute of a centrifugal compressor from the rectangular cross section of the volute. Measurements are carried out using PIV. The results obtained in this study show that the separation region around the tongue is reduced and that the recirculation flow increases as the flow coefficient decreases.

• Journal of Energy Engineering
• /
• v.24 no.4
• /
• pp.124-129
• /
• 2015

An experimental study was performed estimating COP(Coefficient of Performance) of air-conditioning cycle using inverter scroll compressor with and without $Al_2O_3$ nano particle. All experiments were done for various compressor speeds from 1000~4000 rpm and used the inverter controller called CANDY to change the compressor rpm. The air-conditioning cycle components in the apparatus were used as same with components of YF hybrid car. To estimate the COP, this study measured the temperature and pressure at inlets and outlets of compressor, condenser, and evaporator. And also measured the compressor input power using Powermeter. Through the experiments, the maximum error to estimate COP was shown about ${\pm}6.09%$ at 3500rpm. The COP of refrigeration cycle with $Al_2O_3$ nano-particle was similar with that of the base cycle without nano-particle between 1000~3000 rpm of the compressor speed. But, This study showed that the COP of the cycle with $Al_2O_3$ over 3000 rpm of the compressor speed was higher than that of the base cycle due to the higher heat transfer rate increased in the evaporator from the higher oil flow rate inside the cycle as well known. Those results can be used the basic and fundamental data to design the air-conditioning cycle using inverter scroll compressor with $Al_2O_3$ nano particle.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.419-423
• /
• 2000

• Proceedings of the SAREK Conference
• /
• 2003.07a
• /
• pp.160-160
• /
• 2003

• Proceedings of the SAREK Conference
• /
• 2004.06a
• /
• pp.142-142
• /
• 2004

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.10 no.4
• /
• pp.495-507
• /
• 1998

The transient characteristics of a 4.0㎾ inverter driven heat pump was investigated by theoretical and experimental studies. The heat pump used in this study consists of a high side scroll compressor and $\Phi$7 compact heat exchangers with two capillary tubes. A series of tests was peformed to examine the transient characteristics of heat pump in heating and cooling mode when the operating speed was varied from 30Hz to 102Hz. One of the major issues that has not been addressed so far is transient characteristics during speed modulation. A cycle simulation model has been developed to predict the cycle performance under frequency rise-up conditions, and the results of theoretical study were compared with the results of experimental study. The theoretical model was driven from mass conservation and energy conservation equations to predict the operation points of refrigerant cycle and the performances at various operating speeds. For transient conditions, the simulated results are in good agreement with the experimental results within 10%. The transient cycle migration of the liquid state refrigerant causes a significant dynamic change in system. Thus, the migration of refrigerant is the most important factor whenever An experimental analysis is performed or A simulation model is developed.

• Journal of Mechanical Science and Technology
• /
• v.14 no.10
• /
• pp.1061-1071
• /
• 2000

Linear cyclic systems (LCS's) are a class of systems whose dynamic behavior changes periodically. Such a cyclic behavior is ubiquitous in systems with fundamentally repetitive motion. Yet, the knowledge of the noise and vibration transmission paths in LCS's is quite limited due to the time-varying nature of their dynamics. The first part of this two-part paper derives a generic expression that describes how the noise and/or vibration are transmitted between two (or multiple) points in the LCS's. In Part II, experimental validation of the theoretical development of Part I is provided. The noise and vibration transmission paths of the scroll and rotary compressors (two typical LCS's) are examined to show that the LCS's indeed generate a series of amplitude modulated input signals at the output, where the carrier frequencies are harmonic multiples of the LCS' fundamental frequency. The criterion proposed in Part I to determine how well a given LCS can be approximated as a linear time-invariant systems (LTIS) is applied to the noise and vibration transmission paths of the two compressors. Furthermore, the implications of the experimental validations/applications are discussed in order to assess the applicability of the noise/vibration source and transmission path identification techniques based on the assumption that the system under consideration is linear and time-invariant.