• Journal of Korean Society for Atmospheric Environment
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• v.30 no.1
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• pp.59-67
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• 2014

In 1995 Kimchi refrigerator was developed at first, and has used HFC-134a as refrigerant. Kimchi refrigerator has been made 1,044,694 on the basis of 2010, disposed about 160,000 per year. Although mobile air conditioning, commercial refrigerator, general refrigerator is regarded as a major source of HFC-134a, little information is available for its emission characteristics of HFC-134a. This paper addresses the fugitive emission factors of Kimchi refrigerator at use-phase and disposal-phase. The residual quantities of Korean-made fifty three waste Kimchi refrigerators were weighed using a commercial recover of refrigerants to determine the emission factors at the disposal-phase. On the other hand, the emission factors at use-phase were estimated from the residual quantities and operating times. The average residual rate of forty three scarp Kimchi refrigerators is determined to be $74.6{\pm}5.2%$. The emission factor at the use-phase is estimated to be $3.5{\pm}0.8%/yr$ as a result of using average age of 11.7 years and the average residual rate determined here. The emission factor at the disposal-phase is determined to be 31.3% after adopting 58% of the recycling rate of refrigerant reported by Recycling Center. We estimate 3.1 g/yr for the average emission quantity of HFC-134a per operating refrigerator, while 22.5 g for that per waste Kimchi refrigerator. Since the chemical compositions of refrigerant of waste Kimchi refrigerator were the same as those of new refrigerant, it is expected that the HFC-134a recovered from waste Kimchi refrigerator can be reused for refrigerant.

• Resources Recycling
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• v.22 no.4
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• pp.70-80
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• 2013

Waste refrigerator is the most large amount of item being recycled and the recycling process is the most complicated in WEEE (Waste Electrical and Electronic Equipment) because refrigerator is biggest product and consists of various parts and materials such as ferrous, non-ferrous, and plastics. Recently, recycling process of waste refrigerator has been being more complex since large capacity 2 door refrigerators and standing Kimchi refrigerators with various material are distributed on custom market. In addition, recycling of valuable resource from waste refrigerator is mandatory by WEEEs recycling legislation; therefore, high efficiency recycling enough for economic and environment-friendly recovery of valuable resource through present technical situation analysis and comparison of recycling technologies of waste refrigerator with advanced country.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.18-28
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• 1994

An exhaust-heated gas turbine cycle equipped with a waste heat recovery boiler and ammonia absorption-type refrigerator using waste heat is newly devised and analyzed. The general performance of this cycle is compared with that of the conventional gas turbine cycle. This cycle shows a potential high efficiency. When 1500K of gas turbine inlet temperature the efficiency is 53 percent as compared to 45 percent for a conventional combined cycle. Suction cooling of this cycle leads to improve the thermal efficiency and the specific output.

• Journal of IKEEE
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• v.22 no.1
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• pp.156-161
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• 2018

Recently, as the population rapidly increases, food shortages and waste are emerging serious problem. In order to solve this problem, various countries and enterprises are trying research and product development such as a study of consumers' purchasing patterns of food and a development of smart refrigerator using IoT technology. However, the smart refrigerators which currently sold have high price issue and another waste due to malfunction and breakage by complicated configurations. In this paper, we proposed a low-cost smart refrigerator system based on IoT for solving the problem and efficient management of ingredients. The system recognizes and registers ingredients through QR code, image recognition, and speech recognition, and can provide various services of the smart refrigerator. In order to improve an accuracy of image recognition, we used a model using a deep learning algorithm and proved that it is possible to register ingredients accurately.

• Journal of Surface Science and Engineering
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• v.57 no.2
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• pp.92-97
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• 2024

The LiBr aqueous solution, which is the absorption liquid of absorption refrigerator, must be replaced periodically because the concentration of impurities such as Cu²⁺, Fe²⁺, Ca²⁺, etc., increases due to corrosion of the tubes as the period of use increases, and the refrigeration efficiency decreases significantly. In order to reuse the waste absorption liquid, flocculation-precipitation method is mainly applied to precipitate the impurities, which requires hundreds of times the concentration of impurities and generates additional waste. In this study, a process for removing Cu ion impurities from cyclone electrolyzer by electrolytic reduction is presented in a small-scale facility without additional waste. It was confirmed that Cu ion impurities can be removed down to 1 ppm by electrolytic reduction process, and to further improve the removal rate, the mass transfer rate was increased by using a cyclone electrolyzer. The removal rate of Cu ions increased with the increase of flow rate and current density, and it was confirmed that Cu was removed at a rate of 1.48 ppm/h under the condition of 330 mL/sec and 2.5 mA/cm².

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.59-64
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• 2001

On July 5, 1997, environmental Protection Administration of Taiwan publicized the recycling regulation of waste home appliances that include four items, namely, television, refrigerator, washing machine, and air conditioner. It is believed that this regulation pioneers the law enforcement of waste home appliances in the world. To comply with tile policy, several contemporary waste disposal plants specialized in waste home appliances were established according to a follow-up technical specification oil the waste treatment facilities and methodology. Therefore, the traditional dismantling facilities were substituted and waste collection routes were altered as well accordingly. This study investigates the collection and recycling costs of waste home appliances in accordance with these newly established routes and facilities, respectively. Cost survey was conducted among collectors and recycling plants of waste home appliances; consequently, tire collection and recycling costs were analyzed, correspondingly. Results show that the recycling costs of waste home appliances were much higher than that of other waste items. Since the market share of recycled materials is lacking, these waste recycling plants of home appliances can only survive under the subsidy of EPA in Taiwan. Due to some arduous problems, the subsidiary system has already caused serious financial unbalance for a foundation under EPA of Taiwan, which associated with waste recycling in Taiwan.

• Environmental Engineering Research
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• v.24 no.1
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• pp.74-81
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• 2019

Upcycling generally refers to the conversion of waste materials to something useful or valuable and is a useful concept that can be applied not only to the waste design industry but also to waste recycling and resource circulation. Our study highlights upcycling as the key concept for improving the value of waste by redefining the concept as "the recycling of waste materials and discarded products in ways that enhance their value." Four upcycling strategies are linked to material flow analyses conducted on waste electronic and electrical equipment, specifically waste refrigerators and waste computers, to examine the technologies available for implementation and suggest guidelines for the promotion of upcycling. The amount of waste refrigerators collected by the formal sector was 121,642 tons/y and the informal sector, 63,823 tons/y. The current recycling ratio of waste refrigerators was estimated as 88.53%. A total of 7,585 tons/y of waste computers were collected by the formal sector and 3,807 tons/y by the informal sector after discharge. Meanwhile, the current recycling ratio of waste computers was estimated as 77.43%. We found that it is possible to introduce 28 upcycling technologies in the case of refrigerators, and 15 technologies are available to promote upcycling in the case of computers. By refining the broad concept of upcycling and looking at the stages of material flow, our approach presents universally applicable directions for incorporating upcycling in resource recovery and recirculation plans.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.87-95
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• 1997

A chemical heat pump based on the reversible reactions between metal chlorides and ammonia gas is attractive alternative to compression system and liquid absorption systems in cooling and refrigerating fields. The advantages of chemical heat pump are no regulatory constants due to CFC refrigerants, utilization of gas, industrial waste heat, electricity, fuel oil etc. as heat sources and wide applications to energy storage system, large-scale energy managements for industrial process. The scale-up of chemical heat pump from laboratory prototype to pilot plants necessitates the interpretation of system performance and evaluation of dynamic behavior in the chemical reactor. This study contains the prediction of performance of chemical refrigerator according to operating condition, the dynamic simulations through reactor modelling, which is used for the calculation of reactive medium temperature and the conversion variation with reactor cooling temperature, and the effect survey of block parameters on the power of refrigerator.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.15 no.4
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• pp.362-371
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• 1986

In the normal Refrigeration process, the condensation heat of refrigerant s not been used because of its low-temperature waste heat. To recover the condensation waste heat of R-12 refrigerator, a drying and hot water system was designed and experimented. The results obtained were summarized as follows: 1. As the temperature a temosphere was increased, the temperature of discharge gas of compressor was increased. And the temperature was $80-84^{\circ}C$ for air condensing type and was $68-71^{\circ}C$ for water condensing type during summer. 2. The condensation waste heat could be obtained up to $50-55^{\circ}C$ of drying heat-source and Hot water in summer. In this case, recovered rate was about $73\%$. And the more temperature of drying Heat-source and Hot water were increased, the more a recovered rate were decreased. 3. When comparing drying characteristics of Agro-products in dryer of waste heat utilization and Hot air, there was no quality difference in products. But drying time of the former was 3 Hours longer than the latter. 4. The condensation waste heat of compressor could be applied into the drying of marine products, the predrying of agro-products and making hot water. And showed high possibility of the waste heat using in low-temperature storage.

• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.129-138
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• 2013

This paper studies the improvement of a pre-processing line for waste refrigerators in a metropolitan recycling center(MRC). We performed ARENA modeling and simulation by using work analysis and time measurement on the current processing line. Combined this result with some practical experiences from workers, we generated 3 alternatives to improve the current line and evaluated them by using ARENA simulation. The final decision selected consists of changing 2-line process into 1-line and having a separate cell-line for collecting refrigerant. Currently, the result of this study was applied to MRC by improving cycle time, throughput, and space utilization compared to the previous one.