Mobile QR Code QR CODE : Korean Journal of Air-Conditioning and Refrigeration Engineering
Korean Journal of Air-Conditioning and Refrigeration Engineering

Korean Journal of Air-Conditioning and Refrigeration Engineering

ISO Journal TitleKorean J. Air-Cond. Refrig. Eng.
  • Open Access, Monthly
Open Access Monthly
  • ISSN : 1229-6422 (Print)
  • ISSN : 2465-7611 (Online)

Korean Journal of Air-Conditioning
and Refrigeration Engineering

A journal devoted to investigations of HVAC and building technologies in various climatic conditions

• Editors-in-Chief: Doosam Song

LiCl 수용액을 이용한 충전탑식 액체 제습기의 성능평가 Performance Evaluation of Pack-Bed Type Liquid Desiccant Dehumidifier using LiCl Aqueous Solution

https://doi.org/10.6110/KJACR.2024.36.2.65

Dong-Soon Jeon

Liquid desiccant dehumidification systems are among the air conditioning systems that can individually control humidity. Also, these systems have the advantage of effectively removing latent heat from humid air, as well as using low-grade energy sources such as solar heat and waste heat. Because of these advantages, liquid desiccant dehumidification systems have attracted increasing attention, as a potential alternative to the conventional dehumidification methods. Therefore, in this paper, the performance of the liquid dehumidifier according to the process of air conditioning was evaluated. LiCl aqueous solution was used as a working fluid. A material of 150 mm in width, 300mm in depth, and 400 mm in height was used for the experiment. Experimental conditions were chosen using general full factorial DOE, and dehumidification performance according to the experimental conditions was analyzed. The experimental conditions were temperature (30 ~ 40℃), relative humidity (50 ~ 70%), and velocity of (0.75 ~ 1.75 m/s). From the results, the dehumidification effectiveness was mostly affected by the velocity and humidity of the supply air. The dehumidification rate was about 18.7 ∼ 34.8 g/min and dehumidification effectiveness was 25 ∼ 39%.

기계설비 착공 전 확인신청서 작성 실태조사를 통한 제도개선 연구 A Fact-finding Survey and Improvement Plans for Mechanical Equipment Preconstruction Verification Application

https://doi.org/10.6110/KJACR.2024.36.2.73

Hiwon Yun ; Young June Lee ; Jang Sung An

This paper presents the results of a fact-finding survey conducted among on-site mechanical equipment engineers. Additionally, it proposes improvement plans for completing the mechanical equipment preconstruction verification application. Currently, errors occur due to the unclear method of filling out the preconstruction verification application. This leads to a decrease in the quality of construction and undermines the purpose of enforcing the Machinery Equipment Act. Accordingly, this paper proposed a plan to improve the efficiency and accuracy of mechanical equipment construction. First, items for apartment housing information were added. Second, the types of registration certificates for mechanical equipment design, construction work, and supervision were specified to verify the qualifications of companies and personnel. Third, the technical level of the on-site mechanical equipment technician and the on-site mechanical equipment supervisor was required to be written so that the appropriate manpower arrangement could be confirmed. Through this, it is expected that the overall level of mechanical equipment construction can be improved by reducing errors in filling out preconstruction verification applications and increasing the transparency of construction.

공동주택 적용을 위한 액체식 제습 중앙공조시스템의 여름철 현장성능 실증연구 Field Study of a Liquid-Desiccant Central Air-Conditioning System for an Apartment Building

https://doi.org/10.6110/KJACR.2024.36.2.82

Jae-Hee Lee ; Bosun Kim ; Hyungwook Chu ; Jeehoon Yang ; Hyun-Min Nam ; Byoungdoo Lee ; Jae-Weon Jeong

As an alternative to a conventional vapor compression cooling system, a liquid-desiccant central air-conditioning system controlling air temperature and humidity independently, was installed in an apartment building testbed located in Yongin, South Korea. Indoor and supply air conditions of each room were compared, and indoor thermal comfort and energy performance were evaluated under hot and humid weather to verify applicability as a central air-conditioning system for an apartment building. The proposed system can achieve high thermal comfort satisfaction in all rooms, in terms of indoor temperature and humidity distribution and indoor air velocity, when operating for 45 h under the hot and humid weather in summer. The seasonal energy efficiency ratio was estimated to be 1.91, which will increase to 3.40 via the optimization of duct work and the use of energy-efficient fans. Based on the field test results, it can be concluded that the proposed liquid-desiccant system is highly applicable as a central air-conditioning system for multizone apartment buildings.

공조설비 소음저감장치의 설계방법에 따른 압력손실 변화에 대한 실증적 연구 A Study on the Pressure Drop Changes by Design of Noise Mitigation Device in HVAC Equipment

https://doi.org/10.6110/KJACR.2024.36.2.91

Jin Woo Oh

The purpose of this study was to evaluate the impact of noise mitigation device design on pressure drop changes in HVAC equipment. The pressure loss by the noise mitigation device was measured and the change of pressure drop according to the noise mitigation device design was analyzed. Since the main factors determining the pressure loss are the dynamic loss coefficient due to the shape of the noise mitigation device and the flow rate, the pressure loss was tested by varying the length and shape of the noise mitigation device and applying the flow rate step by step. Representative noise mitigation devices for HVAC equipment were silencers and acoustic louver. The noise reduction theory of the two devices is the same but the difference between the two devices is the internal shape. The pressure loss is proportional to the complexity and length of the internal shape of the noise mitigation device. In the case of the silencer, the length is the main factor due to the relatively low dynamic loss coefficient, while for the acoustic louver with a bending shape of a splitter, a higher-pressure loss was measured compared to the silencer and the main factor is the bending angle rather than the length.

기계설비 비정형 데이터 활용 강화를 위한 기계설비산업 정보체계 고도화 정책제언 A Study on Upgrading the Information System of the Mechanical Equipment Industry to Enhance the Utilization of Unstructured Data in Machinery and Equipment

https://doi.org/10.6110/KJACR.2024.36.2.97

Sang Ki Jin ; Su In Chae ; Ja Kang Yang ; Sun Hyo Park

This study explored and suggested ways to improve the information system of machinery and equipment, which is one of the important data required for energy management policies and carbon neutrality policies for urban buildings. The study examined how information system in the Ministry of Land, Infrastructure, and Transport's machinery and equipment industries can increase the utilization value and obtain adequate valuable information from building machinery and equipment through expert research and on-site opinions. The results showed that it is necessary to consider technical policies on how to utilize unstructured data in the machinery and equipment. industries Based on the results, improvement measures for building an information system that can contain unstructured data were derived. In addition, it is necessary to improve the information system platform for the generation and distribution management of unstructured data and to develop technology to process it, and to improve the system and legal improvements that can activate unstructured data.