제습냉방시스템의 제습로터 회전주기변화에 따른 제습성능해석

피창헌(Chang Hun Pi),강병하(Byung Ha Kang),장영수(Young Soo Chang) 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.5

제습냉방시스템에서 주요 구성부품인 제습로터의 성능을 극대화 시키기 위한 방법으로 제습로터의 회전 주기의 제어에 대한 연구를 수행하였다. 열과 물질전달의 과정을 모델화하여 얻은 수치해를 바탕으로 제습로터 성능 시뮬레이션 프로그램을 구성하여, 재생공기 온습도, 풍량 등의 운전조건에 대하여 회전 주기에 따른 제습 로터의 제습량을 구하였다. 성능 시뮬레이션 결과 검증을 위하여, 실험을 통해 측정된 값과 성능해석 모델을 이용하여 계산된 값을 비교함으로써 성능 시뮬레이션 모델의 타당성을 보였다. 각 운전조건에서 제습량이 최대가 되는 제습로터의 회전주기를 최적 회전주기로 정의하였고, 회전주기를 고정(400s)할 때의 제습성능과 비교하여, 최적 회전주기제어가 제습성능에 미치는 영향을 분석하였다. 그리고 회귀분석법을 이용하여 재생온도, 외기상대 습도, 풍량을 변수로 하는 최적 회전주기의 예측상관식을 개발하고 시뮬레이션 값과 비교하여 검토하였다. The performance simulation of a desiccant rotor, which is a core component of a desiccant cooling system, was conducted on the basis of a theoretical solution of the heat and mass transfer process in the rotor. The simulation model was validated by comparing simulation results with experimental data; reasonable agreement was observed. The effect of the rotation speed on the performance of the desiccant rotor was investigated for various operation conditions: temperature (50 to 70°C), humidity ratio (0.01 to 0.02 kg/kg DA), and flow rate of regeneration air. The optimum rotation speed was determined from the maximum moisture removal capacity (MRC) of the desiccant rotor, and it was found to vary with the operation conditions. Further, the correlation for the optimum rotation speed was determined by regression analysis.

제습로터의 공기누설모델 개발 및 성능 특성에 관한 실험적 연구

강병하(Byung Ha Kang),피창헌(Chang Hun Pi),장영수(Young Soo Chang) 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.1

제습로터에서 발생하는 공기누설은 로터와 브러쉬 형태의 누설방지모 틈새의 양단 사이 차압에 의해 발생하는 압력누설이 지배적이며, 실험을 통해 압력누설특성을 파악하였다. 그 결과로, 압력누설량을 로터와 누설방지모의 틈새면적과 차압의 함수로 나타내었다. 위의 상관식을 바탕으로 제습로터의 공기누설모델을 개발하였으며, 실험을 통해 측정된 값과 위 모델을 바탕으로 계산된 값을 비교함으로써 공기누설모델을 검증하였다. 그리고 풍량에 따른 제습로터의 성능실험을 수행하였으며, 공기누설모델을 적용한 성능 분석을 통하여 실질적인 제습량과 공기누설량을 확인 하였다. 또한 동일한 제습로터가 적용된 제습냉방시스템을 고려하여 차압변화에 따른 공기누설의 영향을 공기누설모델을 이용하여 고찰하였다. This study investigates the pressure leakage characteristics of a desiccant rotor with a brush-type air seal. Through a pressure leakage experiment, a correlation equation for the leakage air flow rate is obtained as a function of the air seal area and pressure difference. Using this equation, an air leakage model for the desiccant rotor is developed. By comparing simulation results with the experimental results for the desiccant rotor, the accuracy of the air leakage model is demonstrated. A performance test of a desiccant rotor with various air flow rates is carried out. Using the air leakage model, the effective mass flow rate and air leakage rate are found. In addition, the characteristics of the air leakage are analyzed for a desiccant cooling system using the developed air leakage model.

제습로터 성능지표 제안

이대영,이길봉,김민수 대한설비공학회 2007 설비공학 논문집 Vol.19 No.7

To facilitate comparative analysis on the effects of numerous parameters concerning design and operation of a desiccant rotor, it is firstly required to represent the dehumidification performance as numerical indices. In this work is proposed two performance indices of a desiccant rotor: the humidity effectiveness and the enthalpy-leak ratio. The humidity effectiveness represents the actual dehumidification as compared with the dehumidification in an ideal case, while the enthalpy-leak ratio represents the enthalpy transfer from the regeneration side to the dehumidification side. In an ideal case, the two indices approach one and zero, respectively. The effects of numerous parameters on the dehumidification performance of a desiccant rotor are investigated through numerical simulation and represented with the two indices. The results show that the performance indices are mainly determined by three nondimensional parameters each representing the thermal capacity, the sorption capacity, and the transfer capacity of a desiccant rotor.

재생온도가 저온인 경우 제습로터의 재생부/제습부 면적비율과 회전속도 최적화

정재동,이대영,윤석만 대한설비공학회 2007 설비공학 논문집 Vol.19 No.7

The desiccant rotor is the most essential component of desiccant cooling system, but its design relies on manufacturer’s experience and principles are not yet clear in spite of a lot of theoretical/experimental work published. The mathematical modeling of desiccant rotor needs solution of coupled partial differential equations of heat and mass transfer. In this study, numerical program is developed and validated using a real desiccant rotor. The calculation results are in reasonable agreement with the experimental data and other available numerical results. Optimization of desiccant rotor on the condition of low regeneration temperature are investigated. The optimal rotor speed at which the process outlet humidity becomes minimized, shows same as that of the system optimization. Compared to high regeneration temperature, broad is the range of optimal speed of low regeneration temperature. Systematic analysis on the optimal area ratio of regeneration to dehumidification section has also been conducted.

제습냉방시스템에서 요소성능이 시스템성능에 미치는 영향

장영수,이대영 대한설비공학회 2007 설비공학 논문집 Vol.19 No.10

Cycle simulation is performed for two types of the desiccant cooling system incorporating a regenerative evaporative cooler. The cooling capacity and COP are evaluated at various effectiveness values of the regenerative evaporative cooler, the desiccant rotor and the sensible heat exchanger. As either of the effectiveness of the regenerative evaporative cooler or the humidity effectiveness of the desiccant rotor increases, both the cooling capacity and COP increase, but the enthalpy leak ratio gives the opposite effect on the system performance. It is found that COP of cycle A mainly depends on the humidity effectiveness of the desiccant rotor, while for cycle B enthalpy leak ratio of desiccant rotor has the major impact on COP. The effect of the sensible heat exchanger on the cooling capacity is small about 1/10 compared with those of other components.

제습제와 채널이 제습로터 성능에 미치는 영향

정재동,이대영,윤석만 대한설비공학회 2007 설비공학 논문집 Vol.19 No.8

The desiccant rotor is the most essential component of desiccant cooling system, but one of its drawbacks to spread out is rotor size. To reduce the size of rotor the analysis of rotor performance is crucial. Systematic examination on the effect of desiccant and channel geometrics has been conducted based on the numerical program previously developed. Considered parameters related to channel geometrics are channel shape and cross section area of channel, and parameters related to desiccant are mass fraction, heat capacity, density, maximum water uptake and separation factor of isotherm. Considerable reduction of rotor size is expected by adjusting the parameters.

제습로터 회전속도에 따른 성능 시뮬레이션

피창헌(Chang Hun Pi),장영수(Young Soo Chang),강병하(Byung Ha Kang),강명철(Myeong Cheol Kang) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

The performance simulation has been conducted based on a theoretical solution of the heat and mass transfer process in a desiccant rotor, which is a core component of a desiccant cooling system. The simulation model was validated by comparing simulation results with experimental data. The calculation results are in reasonable agreement with experimental results. The effect of the rotation speed on the performance of desiccant rotor has been investigated for various operation conditions; temperature (50 to 70℃), humidity ratio (0.01 to 0.02 kg/kg DA), and flow rate of regeneration air. The optimum rotation speed was obtained based on maximum moisture removal capacity(MRC) of desiccant rotor, and the optimum rotation speed varies according to operation conditions. Also constant rotation speed (400s) at which the MRC seems to be evenly high for various operation conditions is founded by comparing the optimum rotation speed for the MRC.

고분자 제습로터의 저온재생 성능시험

이진교(Jin-Kyo Lee),이대영(Dae-Young Lee),오명도(Myung-Do Oh) 대한설비공학회 2009 대한설비공학회 학술발표대회논문집 Vol.2009 No.-

The polymeric desiccant rotor is made from the super absorbent polymer by ion modification. The moisture sorption capacity of the super desiccant polymer(SDP) is 4 to 5 times larger than those of common desiccant meterials such as silica gel or zeolite. It is also known that SDP can be regenerated even at the relatively low temperature. To fabricate the desiccant rotor, firstly the SDP was laminated by coating the SDP on polyethylene sheet. Then corrugated and rolled up into a rotor. The diameter, the depth, the dimensions of the corrugated channel, etc. were pre-determined from numerical simulation on the heat and mass transfer in the desiccant rotor. The dehumidification performance was tested in a climate chamber. The relevant tests were carried out at the process air inlet temperature of 32℃, the regeneration air inlet temperature of 60℃ and the inlet dew-point temperature of both the process air and the regeneration air of 18.5℃.when the rotation period is long, the moisture sorption is not effective. In the desiccant rotor developed in this study, the optimum rotation period is found about 350s at the regeneration temperature of 60 ℃. It was found from further experiments that the optimum rotation tends to decreases as the regeneration temperature increases. Meanwhile, the outlet temperature of the process air deceases monotonically as the rotation period increases.

고분자 제습로터의 운전 변수가 성능에 미치는 영향

이진교(Jin-Kyo Lee),이대영(Dae-Young Lee),오명도(Myung-Do Oh) 대한설비공학회 2010 대한설비공학회 학술발표대회논문집 Vol.2010 No.6

In this study, The polymeric desiccant rotor is made from the super absorbent polymer by ion modification. It is known that Super Desiccant Polymer(SDP) can be driven by low-grade waste heat. To fabricate the desiccant rotor, firstly the SDP was laminated by coating the SDP on polyethylene sheet. Then corrugated and rolled up into a rotor. The diameter, the depth, the dimensions of the corrugated channel, etc. were pre-determined from numerical simulation on the heat and mass transfer in the desiccant rotor. The dehumidification performance was tested in a climate chamber. The relevant tests were carried out at the process air inlet temperature of 32℃, the regeneration air inlet temperature of 55℃-70℃ and the inlet dew-point temperature of both the process air and the regeneration air of 18.5℃. when the rotation period is long, the moisture sorption is not effective. In the desiccant rotor developed in this study, the optimum rotation period is found about 300s at the regeneration temperature of 60℃. It was found from further experiments that the optimum rotation tends to decreases as the regeneration temperature increases. Meanwhile, the outlet temperature of the process air deceases monotonically as the rotation period increases.

이론적 방법에 의한 제습로터 최적 회전속도의 결정

이대영(Dae-Young Lee),송귀은(Gwi-Eun Song) 대한설비공학회 2009 설비공학 논문집 Vol.21 No.10

The optimum rotation speed of a desiccant rotor is studied theoretically based on a theoretical solution to the heat and mass transfer processes in the desiccant rotor. A simple correlation equation for the optimum rotation speed is derived to show the effects of various parameters including the thermo-physical properties, the geometric dimension, and the operating condition of the desiccant rotor. The theoretical result is compared with existing experimental data to validate the linearization and simplification included in the solution procedure. Based on the theoretical solution, the effects of major parameters on the optimum rotation speed are studied and the fundamental mechanism of the influences is investigated.