• 월간 기계설비
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• s.30
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• pp.91-97
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• 1993

원적외선은 인류가 최초로 이용한 난방열원이다. 불을 사용하기 이전의 유일한 난방은 태양열을 받는 것이었으며, 그 태양열 중 인체를 따뜻하게 해주는 빛이 바로 원적외선이기 때문이다. 현대 과학에서는 이미 1920년대에 원적외선 난방이론이 정립되었으며, 1940년대에 들어서는 미국에서 원적외선 튜브히터가 개발되어 충고가 높고 면적이 넓어 다른 난방시스템으로는 불가능했던 산업 및 상업용건물의 난방이 가능해졌을 뿐만 아니라 복사난방의 대표적인 시스템으로 인정되고 있다. 우리나라의 경우는 `80년대 초반부터 원적외선 히터가 선보이기 시작했고, 극히 일부 공장건물에 사용된 실적이 있으나 아직까지 원적외선 난방시스템 자체에 대한 인식이 부족하고 이 분야에 대한 자료 또한 전무한 실정이다. 이에 필자는 수년간 외국(특히 미국)의 자료를 분석하고 현지를 답사하므로써 확인될 수 있었던 원적외선 난방시스템의 유용성을 토대로 하여 이론과 실제적인 내용을 다루어 보고자 하는 것이다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.6
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• pp.512-518
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• 2002

The real chip and similarity model were used to investigate the thermal behavior and velocity distribution of air from the heat source with the location and the amount of heat experimentally and numerically, and compared. The heat generated in the block is not cooled by convection and show the high temperature by the stagnation of heat flow. After maintaining the high temperature of block by the natural convection, the sudden drop of temperature with the air flow was shown in the channel but the decreasing rate was small with the time. The inward block was effected by infinitesimal air flow generated between block and channel and outward block was effected by the entry condition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.10
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• pp.854-862
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• 2002

In the previous research, a simplified correlation method was developed as an easy prediction tool for comparing energy use of cooling plants. The purpose of this paper is to test the applicability of this method for economic evaluation with two zones of a 20-story commercial building in Seoul. The results of this method were compared with the DOE-2 simulation and actual measured data. Then, Comparisons of life cycle cost were carried out for three types of cooling plants. Testing of one zone showed good agreement of within 10% error in cooling energy use and within 2% error in LCC. But testing of the other zone indicated that the use of this method were invalid when input variables were used beyond its valid range.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.9
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• pp.881-888
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• 2004

Control algorithms for a dual source chiller air conditioning system were developed. These are control algorithms for the supply air temperature control, the supply header chilled water temperature control, the chiller chilled water temperature control, and the cooling tower water temperature control. These algorithms were analyzed by using a dynamic simulation program. Simulation results showed the energy savings and the satisfactory controls of an absorption and centrifugal chiller air conditioning system. Therefore, control algorithms developed for this study may effectively be used for the improved controls of the dual source chiller air conditioning system.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.201-201
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• 2007

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.22-22
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• 2007

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.480-483
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• 2008

The cold-air distribution system is expected as an efficient method to reduce energy consumption in the air-conditioning system. We introduced some control strategies for the system by summarizing some references in the view point of energy saving. Direct digital control is specially emphasized as an important control technique for the system. Some drawbacks which habe been conventionally mentioned to apply the cold-air distribution to real fields can be solved by using the technique. The control strategy which is introduced in here will be available to build control system for the air-conditioning based on the cold-air distribution for energy saving.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.248-248
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• 2003

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.6
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• pp.505-513
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• 2001

A revised VX cycle using ammonia/water as the working fluid is a cycle which is suitable to produce cooling utilizing low temperature hat sources. The cycle was analyzed numerically to investigate the effects of the design and operating conditions on the performance. It was shown that both COP and cooling capacity were significantly influenced by the performance of he rectifier. Insufficient UA of the rectifier reduced both ammonia mass fraction and mass flow rate of the vapor entering the condenser, which produced cooling effect in the evaporator. As the temperature and the mass flow rate of the heat source increased, both COP and exergetic efficiency decreased due to the irreversibilities produced in heat exchangers, but cooling capacity did not vary much. Cooling capacity increased significantly as the coolant temperature decreased, although COP and exergetic efficiency remained nearly constant.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.3
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• pp.339-348
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• 1999

A computer model was developed in order to predict the temperature distribution and the performance of the vertical tube-in-tube ground coil heat exchanger. This model has been validated by experimental results conducted by ORNL. The heat exchanger performance with the variation of the length is calculated and compared. As results, the heat exchanger performance is proportional to the length but the performance per unit length decreases. The minimum performance of 70m - PVC heat exchanger during cyclic operation for a week is obtained 20,054kJ/h for cooling operation and 13,915kJ/h for heating operation. And minimum temperature difference is $4.64^{\circ}C$ for cooling operation and $2.64^{\circ}C$ for heating operation. In each case, it is noted that the temperature difference between the pipe and the far-field occurs within 0.8m from the heat exchanger.