• 대한기계학회논문집B
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• 제25권10호
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• pp.1318-1326
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• 2001

The evaporation heat transfer coefficient and pressure drop for refrigerant R-22 flowing in the plate and shell heat exchanger were investigated experimentally in this study. Two vertical counterflow channels were farmed in the exchanger by three plates of commercial geometry with a corrugated trapezoid shape of a chevron angel of 45 ° Upflow boiling of refrigerant R-22 in one channel receives heat from the hot downf1ow of water in the other channel. The effects of the mean vapor quality, mass flux, heat flux and pressure of R-22 on the evaporation heat transfer and pressure drop were explored. The quality change of R-22 between the inlet and outlet of the refrigerant channel ranges from 0.03 to 0.05. The present data showed that both the evaporation heat transfer coefficient and pressure drop increase with the vapor quality. At a higher mass flux, the evaporation heat transfer coefficient and pressure drop are higher for the entire range of the vapor quality Raising the imposed wall heat flux was found to slightly improve the heat transfer, while at a higher refrigerant pressure, both the heat transfer and pressure drop are slightly lower.

• 설비공학논문집
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• 제16권9호
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• pp.845-854
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• 2004

The evaporation heat transfer coefficient for R-l34a, R-407C (a mixture of 23wt% R-32, 25 wt% R-125, and 52 wt% R-l34a) and R-410A (a mixture of 50 wt% R-32 and 50 wt% R-125) flowing in the oblong shell and plate heat exchanger were investigated experimentally in this study. Four vertical counterflow channels were formed in the exchanger by four plates of commercial geometry with a corrugated sinusoid shape of a chevron angle of 45 degree. The effects of the mean vapor quality, mass flux, heat flux, and saturation temperature of different refrigerants on the evaporation heat transfer were explored in detail. Similar to the case of a Plate heat exchanger, even at a very low Reynolds number, the flow in the oblong shell and plate heat exchanger remains turbulent. It is found that the evaporation heat transfer coefficient in the plates is much higher than that in circular pipes. The present data show that the evaporation heat transfer coefficients of all refrigerants increase with the vapor quality. At a higher mass flux h, is higher than for the entire range of the vapor quality. Raising the imposed wall heat flux was found to slightly improve h$_{r}$, while h$_{r}$ is found to be lower at a higher refrigerant saturation temperature. A comparison of the performance of the various refrigerants reveals that R-410A has the highest heat transfer performance followed by R-l34a, and R-407C had the lowest performance of the refrigerants tested. Based on the present data, empirical correlations of the evaporation heat transfer coefficient were proposed.sed.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1748-1755
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• 2001

The shell and tube heat exchangers were introduced to apply to a big capacity condenser and a high pressure feed water heater for power plant in the beginning of 1990s. Design and manufacturing technology fur shell and tube heat exchangers have been developed until now. But it is very difficult to calculate the expected performance characteristics of the shell and tube heat exchanger, because there are many design parameters to be considered according to internal structure and the shell side heat transfer mechanism complicately related to the design parameters. Design parameters to be considered in the design stage of shell and tube heat exchanger are shell and tube side fluids, flow rate, inlet and outlet temperature, physical properties, type of heat exchanger, outer diameter, thickness, length of tube, tube arrangement, tube pitch, permissive pressure loss on both sides, type of baffle plate, baffle cutting ratio. The propose of study is an analysis TEMA(Tubular Exchanger Manufacturers Association) E shell and tube heat exchanger performance with changing a number of baffles(3, 5, 7, 9, 11) and tubes(16, 20) and determined optimal baffle spacing.

• 한국생산제조학회지
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• 제8권1호
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• pp.89-99
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• 1999

The automatic design of shell & tube type oil cooler can be used in real industrial environments. Since the automatic design system is intended to be used in small companies, it is designed to be operated well under environments of CAD package in the personal computer. It has adopted GUI in design system, and has employed DCl language. Design parameters to be considered in the design stage of shell and tube type oil cooler are type of oil cooler, outer diameter, thickness, length of tube, tube arrangement, tube pitch, flow rate, inlet and outlet temperature, physical properties, premissive pressure loss on both sides, type of baffle plate, baffle plate cutting ratio, clearance between baffle plate outer diameter and shell inner diameter and clearance between baffle plate holes. As a result, the automatic design system of shell & tube type oil cooler is constructed by the environment of CAD software using LISP. We have built database of design data for various kinds of shell & tube type oil coolers. The automatic design system have been assessed and compared with existing specification of design. Good agreement with Handbook of heat exchanger and design dta of real industrial environments has been found.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1002-1007
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• 2009

The research are performed to check the characteristics of the ice slurry transport system for the district cooling. The system are installed at the 1st floored building which is as large as the $1204\;m^2$ ($86\;m{\times}14\;m$). Three kinds of heat exchanger are selected, such as, plate, spiral and shell & tube type, to apply to the ice slurry systems. Experiment was done in the two cases. The first case, circulation water flow fixed at the design conditions for the state to change the flow of the supply of ice slurry. The second case, Ice slurry flow fixed at the design conditions for the state to change the flow of circulation water. Both side of Energy balance was calculated. The performance of plate heat exchanger is higher than others and it's enthalpy effectiveness is higher too.

• 한국전산유체공학회지
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• 제21권4호
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• pp.28-32
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• 2016

In the previous study, it is proved by numerical simulation that the baffle shaped as the porous plate installed in the inlet chambers improves the redistribution of the flow injecting to the tube bundles. In the present study, numerical simulation has been performed to investigate the effects of the flow distributors on the thermal characteristics of the shell and tube heat exchangers. The flow fields have been analysed by the three-dimensional Navier-Stokes solvers including the thermal conditions on the shell sides. The numerical results showed that the presence of the baffles improves the redistribution of the heat transfer to the tube bundles though the overall performance drop slightly on the present flow conditions.

• 설비공학논문집
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• 제13권10호
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• pp.930-938
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• 2001

In this study, evaporation pressure drop experiments were conducted with two types of plate and shell heat exchangers (P&SHE) using R-22. An experimental refrigerant loop has been established to measure the evaporation pressure drop of R-22 in a vertical P&SHE. The flow channels were formed by adding three plates having a corrugated channel of a chevron angle of $45^{\circ}$. The R-22 flows down in one channel exchanging heat with the hot water flowing up in the other channel. The effect of the refrigerant mass flux, average heat flux, system pressure and vapor quality were explored in detail. During the experiment, the quality change between the inlet and outlet of the refrigerant channel ranges from 0.03 to 0.15. The present data showed that two types of P&SHE have similar trends. The pressure drop increases with the vapor quality for both types of P&SHE. At a higher mass flux, the pressure drop is higher for the entire range of the vapor quality. Also, the increase in the average heat flux increases the pressure drop. Finally, at a higher system pressure, the pressure drop is found to be slightly lower.

• 동력기계공학회지
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• 제16권4호
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• pp.24-29
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• 2012

The numerical analysis by using CFX 11.0 commercial code was done for prediction of fluid flow and thermal field in the vertical heat exchanger. The present experimental studies were also conducted to investigate the effects of circulating solid particles on the fluid flow and temperatures in the fluidized bed vertical shell and tube type heat exchanger with counterflow, at which the solid particles of glasses (3 $mm{\Phi}$) were used in the fluidized bed with a smooth tube. The effect of circulation on the distance(L) of tube inlet and baffle plate was also examined. The present experimental and numerical results showed that the particles in the distance (Ds) of 15 mm showed a more efficient circulation without stacked the space and the LMTD(Log Mean Temperature Difference) in the fluidized bed type was much lower than that in the typical type shell and tube heat exchanger.

• 한국전산유체공학회지
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• 제19권3호
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• pp.20-23
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• 2014

The flow pattern inside the inlet chamber of the tube side is one of the key parameters influencing on the performances of the shell-and-tube type of heat exchangers(STHE). In order to improve the flow distribution, the baffle shaped as the porous plate is installed in the inlet chambers. In the present study, numerical simulation has been performed to investigate the flow features of the tube side of the STHE in sense of the hydraulic performances. The flow fields have been analysed by the three-dimensional Navier-Stokes solvers with the proper turbulent models. Computational domain is ranged in the whole of the tube side of the STHE. The numerical results showed that the presence of the baffles improves the redistribution of the flow injecting to the tube bundels. The good agreements of the numerical results with the experimental results of PIV measurements have been shown for the validation of the numerical methods adopted in the present papers.

• Journal of Advanced Marine Engineering and Technology
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• 제38권6호
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• pp.639-647
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• 2014

지구 온난화와 화석 연료 고갈로 인해 $CO_2$ 저감과 효율 상승을 동시에 만족하는 기술 개발이 요구된다. 배기 열 회수 기술은 두 가지를 모두 만족할 수 있는 대표적인 기술이다. 본 연구는 배기 열 회수 장치를 위한 세 가지 형식의 증발기용 열교환기를 배기관에 설치하여 실험 및 분석하였다. 고속최대부하에서 판형 열교환기의 배압이 가장 높아지고 실린더 최고 압력이 낮아지며 일산화탄소 배출량도 증가하였다. 또한 고속에서 배압이 2배 이상 증가하며 연료소비율이 2% 증가되어 열교환기 중 가장 높은 증가량을 나타내었다. 핀 튜브 열교환기는 전반적으로 배기 배출물이 적게 배출되고 연료소비율도 가장 적게 나타났다. 쉘 앤 튜브는 판형과 핀 튜브 성능의 중간정도이다. 엔진에 미치는 영향으로만 판단할 때 핀 튜브 열교환기가 배기 열 회수에 가장 적합한 열교환기로 판단된다.