• Title/Summary/Keyword: Hybrid air-conditioner

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Study on the Armature Winding Design of Interior Permanent Magnet Synchronous Motor for Maximum Power (최대 출력 확보를 위한 매입형 영구자석 전동기의 전기자 권선설계)

  • Lim, Ho-Kyoung;Lee, Jeong-Jong;Lee, Tae-Guen;Hong, Jung-Pyo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.875_876
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    • 2009
  • Recently, Interior Permanent Magnet Synchronous Motor(IPMSM) is widely used in the industry applications such as power train for hybrid vehicles and compressor motors of air-conditioner due to its high power density and wide speed range. There are some ways for confirming of maximum power in IPMSM. However, This paper suggests that there is a way about making sure maximum power by reducing turn numbers of armature winding. Setting up the voltage equation through the equivalent circuit and vector diagram of IPMSM first, and then estimating the parameter and power of IPMSM by changing the turn numbers of armature winding and voltage. In order to satisfy output power, the turn numbers of armature winding is changed by using the characteristic analysis, and then checking whether secure maximum power or not.

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Sensorless Controller Development of IPMSM to Drive Air-conditioner Compressor in a Hybrid Electrical Vehicle (하이브리드 전기자동차를 위한 에어컨 압축기용 IPMSM의 센서리스 제어기 개발)

  • Song, Doo-Young;Kwak, Sang-Hyun;Tao, Yu;Song, Sung-Geun;Lee, Sung-Ho;Jung, Tae-Uk;Park, Sung-Jun
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.970-971
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    • 2008
  • 본 논문은 하이브리드 전기자동차를 위한 에어컨 압축기용 구동 드라이브에 대해 연구하였다. 전기자동차의 경우 열악한 환경에서 구동되기 때문에 센서리스 타입은 필수적이며, 고효율화와 고집적화를 위해서 매입형 영구자석 전동기 IPMSM (Interior Permanent Magnet Synchronizing Motor)을 사용하였다. 본 논문에서 사용된 IPMSM은 비정현적인 역기전력과 입력전류를 가지기 때문에 기존 IPMSM의 센서리스 방식은 불가능하다. 이를 해결하기 위해 최소차원의 관측기를 구성하고 속도함수에 의한 가변차단주파수에 의한 강인한 필터회로를 이용한 새로운 제어 알고리즘을 제안하였다.

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A Study on the Performance Improvement of Rotor Structure Modifications in Single-Phase Motors for Compressor Applications (압축기용 단상 전동기의 회전자 자계구조 변경에 따른 성능에 관한 연구)

  • Tae-Uk Jung
    • Journal of the Korean Society of Industry Convergence
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    • v.27 no.2_2
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    • pp.325-332
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    • 2024
  • Contemporary power systems demand efficient and sustainable technologies. Single-phase induction motors, while widely used, face efficiency challenges due to inherent rotor losses. Proposed solutions include the Line-start Permanent Magnet Synchronous Motor (LSPMSM), leveraging permanent magnets for enhanced energy density but facing demagnetization and cost issues. Alternatively, the Line-start Synchronous Reluctance Motor (LSRM) operates as a hybrid motor without permanent magnets, reducing rotor losses and potentially improving efficiency. This paper focuses on designing an LSRM rotor for air conditioner compressors, analyzing start-up characteristics and efficiency through finite element analysis. A comparative study with single-phase induction motors provides insights for future motor technology selection, balancing efficiency and other requirements.

Noise Robust Text-Independent Speaker Identification for Ubiquitous Robot Companion (지능형 서비스 로봇을 위한 잡음에 강인한 문맥독립 화자식별 시스템)

  • Kim, Sung-Tak;Ji, Mi-Kyoung;Kim, Hoi-Rin;Kim, Hye-Jin;Yoon, Ho-Sub
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.190-194
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    • 2008
  • This paper presents a speaker identification technique which is one of the basic techniques of the ubiquitous robot companion. Though the conventional mel-frequency cepstral coefficients guarantee high performance of speaker identification in clean condition, the performance is degraded dramatically in noise condition. To overcome this problem, we employed the relative autocorrelation sequence mel-frequency cepstral coefficient which is one of the noise robust features. However, there are two problems in relative autocorrelation sequence mel-frequency cepstral coefficient: 1) the limited information problem. 2) the residual noise problem. In this paper, to deal with these drawbacks, we propose a multi-streaming method for the limited information problem and a hybrid method for the residual noise problem. To evaluate proposed methods, noisy speech is used in which air conditioner noise, classic music, and vacuum noise are artificially added. Through experiments, proposed methods provide better performance of speaker identification than the conventional methods.

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

An Experimental Study on Radiation/Convection Hybrid Air-Conditioner (복사-대류 겸용 하이브리드 냉방기에 대한 실험 연구)

  • Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.288-296
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    • 2019
  • Radiation cooling has used ceilings or floors as cooling surfaces. In such cases, to avoid moisture condensation on the surface, the surface temperature needs be higher than the dew point temperature or an additional dehumidifier is added. In this study, with a goal for residential application, intentional moisture condensation on the cooling surface was attempted, which increased the cooling capacity and improved the indoor comfortness. This method included two separate refrigeration cycles - convection-type dehumidifying cycle and the panel cooling cycle. Test results on the panel cooling cycle showed that, at the standard outdoor ($35^{\circ}C/24^{\circ}C$) and indoor ($27^{\circ}C/19.5^{\circ}C$) condition, the refrigerant flow rate was 8.8 kg/h, condensation temperature was $51^{\circ}C$, evaporation temperature was $8.8^{\circ}C$, cooling capacity was 376 W and COP was 1.75. Furthermore, the panel temperature was uniform within $1^{\circ}C$ (between $13^{\circ}C$ and $14^{\circ}C$). As the relative humidity decreased, the cooling capacity decreased. However, the power consumption remained approximately constant. In the convection-type dehumidification cycle, the refrigerant flow rate was 21.1 kg/h, condensation temperature was $61^{\circ}C$, evaporation temperature was $5.0^{\circ}C$, cooling capacity was 949 W and COP was 2.11 at the standard air condition. When both the radiation panel cooling and the dehumidification cycle operated simultaneously, the cooling capacity of the radiation panel cycle was 333 W and that of the dehumidification cycle was 894 W, and the COP was 1.89. As the fan flow rate decreased, both the cooling capacity of the radiation panel and the dehumidification cycle decreased, with that of the dehumidification cycle decreasing at a higher rate. Finally, a possible control logic depending on the change of the cooling load was proposed based on the results of the present study.

Numerical investigation into cavitation flow noise of hydrofoil using quadrupole-corrected Ffowcs Williams and Hawkings equation (사중극자 보정 Ffowcs Williams and Hawkings 방정식을 이용한 수중 익형 공동 유동소음에 대한 수치적 고찰)

  • Ku, Garam;Ryu, Seo-Yoon;Cheong, Cheolung
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.5
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    • pp.263-270
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    • 2018
  • In most industry fields concerning external flow noise problems, the hybrid computational aeroacoustic techniques based on the FW-H (Ffowcs Williams and Hawkings) equation are widely used for its numerical efficiency. However, when the surface integral form of FW-H equation is used without volume quadrupole sources, it is known to generate significant non-physical noise in a certain case. Especially, in the case of a flow in which the tip vortex cavitation is formed in the distant downstream direction such as flow driven by an underwater propeller, the accuracy in noise prediction becomes poor unless it is not properly modelled. Therefore, in this study, the nonphysical acoustic waves caused by the surface integral form of FW-H equation is reduced by adding the quadrupole correction term. First, to verify the accuracy of the in-house code of FW-H equation, the noise by an axial fan used in the outdoor unit of air conditioner was calculated and compared with the results of ANSYS Fluent. In order to verify the effects of the quadrupole correction term, the noise prediction for isentropic vortex convection is performed and it is confirmed that the error is reduced by the quadrupole correction term. Finally, the noise prediction is performed for the flow field generated by the Clark-Y hydrofoil in underwater. It is confirmed that the error caused by the cavitation passing through the integral surface can be reduced by the quadrupole correction term.