Performance comparison for oil−water heat transfer of ...

Post on 08-Feb-2023

0 views 0 download

Transcript of Performance comparison for oil−water heat transfer of ...

J. Cent. South Univ. (2016) 23: 2720−2727 DOI: 10.1007/s11771-016-3333-4

Performance comparison for oil−water heat transfer of circumferential overlap trisection helical baffle heat exchanger

WANG Wei-han(王伟晗)1, CHENG Dao-lai(程道来)1, LIU Tao(刘涛)2, LIU Ying-hao(刘颖昊)2

1. College of Urban Construction and Safety Engineering, Shanghai Institute of Technology, Shanghai 201418, China;

2. Energy and Environment Research Institute, Baoshan Iron & Steel Co., Ltd, Shanghai 201900, China

© Central South University Press and Springer-Verlag Berlin Heidelberg 2016

Abstract: The performance tests were conducted on oil–water heat transfer in circumferential overlap trisection helical baffle heat exchangers with incline angles of 12°, 16°, 20°, 24° and 28°, and compared with a segmental baffle heat exchanger. The results show that the shell side heat transfer coefficient ho and pressure drop Δpo both increase while the comprehensive index ho/Δpo decreases with the increase of the mass flow rate of all schemes. And the shell side heat transfer coefficient, pressure drop and the comprehensive index ho/Δpo decrease with the increase of the baffle incline angle at a certain mass flow rate. The average values of shell side heat transfer coefficient and the comprehensive index ho/Δpo of the 12° helical baffled scheme are above 50% higher than those of the segmental one correspondingly, while the pressure drop value is very close and the ratios of the average values are about 1.664 and 1.596, respectively. The shell-side Nusselt number Nuo and the comprehensive index Nuo·Euzo

−1 increase with the increase of Reynolds number of the shell side axial in all schemes, and the results also demonstrate that the small incline angled helical scheme has better comprehensive performance. Key words: performance experiments; helical baffled heat exchangers; circumferential overlap of baffles; incline angle of baffle; heat transfer enhancement

1 Introduction

The segmental baffled heat exchangers (sgSTHXs) are traditional and mature shell-and-tube heat exchangers (STHXs) which are widely used in various industrial fields, such as petroleum refining, power generation and chemical process. However, they have some drawbacks including stagnant zones, higher pressure drops, and a propensity to induce vibration and fouling. Based on these reasons, YOU et al [1−2] designed the STHX with flower baffles (fbSTHX) and with trefoil-hole baffles (thbSTHX), and the results verified that they are of good thermo hydraulic performance and less liable to foul. On the other hand, some researchers improved the performance of sgSTHX by replacing segmental baffles with the helical ones. LUTCHA and NEMCANSKY [3] used planar surface quadrant sector baffles to replace the curved surface ones to achieve the spiral flow in the helical baffled heat exchangers (HSTHX). But the adjacent baffles can form the V gap, which can cause the leakage flow and affect the performance of the heat exchanger. Many researchers paid attention to the phenomenon and put forward some improved measures,

which were focused on the optimum incline angle of the sector baffles and the baffle shapes and connection configurations. It is clear that with the increasing velocity, the smaller the incline angles of the sector baffles are, the higher the heat transfer coefficient and the pressure drop are. LUTCHA and NEMCANSKY [3] indicated that the optimum incline angle of the sector baffles is 40° in the chart of heat transfer coefficient ho versus pressure drop Δpo. However, JAFARI NASR and SHAFEGHAT [4] obtained a fluctuated curve of heat transfer coefficient versus incline angle. STEHLIK et al [5−7] thought that the optimal helical angle for comprehensive performance of helical baffle heat exchanger was 40°, and proposed to use axial-overlap method to reduce the thread pitch and the leakage flow from the V gap of the adjacent baffles. WANG et al [8] tried to block the V gap with plates, but the experimental results indicated that the comprehensive index of heat transfer coefficient was lower than that of the non-block scheme and the pressure drop increased greatly. WANG et al [9−11] used continuous helical baffles to replace non-continuous helical baffles, and the experimental results showed that the heat transfer performance of the continuous helical baffle heat exchanger was better than the segmental baffle heat

Foundation item: Project(50976035) supported by the National Natural Science Foundation of China; Project(4521ZK120064004) supported by the Science

and Technology Commission Green Energy and Power Engineering of Special Fund Project of Shanghai, China Received date: 2015−06−23; Accepted date: 2015−11−19 Corresponding author: CHENG Dao-lai, Professor, PhD; Tel: +86−13311998959; E-mail: darkliu@sohu.com

J. Cent. South Univ. (2016) 23: 2720−2727

2721

exchanger, and the greater the flow velocity is, the more obvious the advantage is. However, compared with the non-continuous helical baffle (such as quadrant and trisection baffles) heat exchanger, the shortcoming of the continuous helical baffle heat exchanger is higher manufacturing difficulty and the higher cost. JI et al [12−13] adopted numerical simulation to prove the staggered overlap helical baffle and continuous helical baffle can effectively improve the comprehensive performance of the heat exchanger. SONG et al [14] designed a kind of baffle structure which widened two straight edges of fan-shaped baffles to form the structure of overlap helical baffles to prevent the short circuit flow, and the experiments showed that the heat transfer performance of this baffle structure was obviously improved. LIN et al [15] applied HTRI software to simulate the best helical angle of helical baffle heat exchanger, and considered that if the shell diameter was certain the optimal helical angle was also certain and the change of the shell side flow rate had no effect on the optimal helical angle. But the simulation result needs to be verified by the plenty of experiments. CHEN et al [16−19] proposed the trisection helical baffled heat exchangers design, especially the circumferential overlap trisection helical baffled shell- and-tube heat exchanger (cothSTHX), which was more suitable to the equilateral triangular tube layouts and had better thermo-hydraulic performances in physical structure. The design of circumferential overlapped of adjacent baffles can minimize the short-cut leakage loss at triangular conjunction notches and improve the rigidity of the heat exchanger tube bundle as well, which were proved by numerical simulation and experimental research. WANG et al [20−21] used fold baffles blocked the triangle leakage zone near the joint point between two plain baffles. In the testing scope the overall heat transfer coefficient increased 7.9%−9.7%, while the shell side pressure drop increased 2.9%−8.0%, and the thermal performance factor TEF enhanced by 28.4−30.7%. DU et al [22−23] put forward a kind of sextant sector helical baffles heat exchanger with six pieces of quadrant sector baffles in each cycle. It also used circumferential overlap to reduce the leakage flow from the V gap, and the study suggested that the comprehensive heat transfer performance was best when the helical angle was 40°.

Compared with the above-mentioned folding baffle and sextant sector baffle schemes, the circumferential overlap trisection helical baffle design was liable to be used in practice as minimal number of parts and simpler structure. In addition, as a new heat exchanger must meet the demand of heat transfer firstly, the larger incline angle design for the pursuit of the best heat transfer coefficient of unit pressure drop at the shell side often

can not meet the target of the heat transfer coefficient. So, this work discusses the performances of circumferential overlap trisection helical baffle heat exchanger with incline angles of 12°, 16°, 24° 20° and 28°, and gives the comparison between it and the segmental baffle heat exchanger in order to research the application of circumferential overlap trisection helical baffles scheme in the smaller incline angle range. 2 Performance test rig

The heat exchanger performance test rig was built by Shanghai Institute of Technology and Southeast University, China. It contains two separate systems of oil−water and water−water heat transfer. There are three kinds of heat exchangers in the test rig, shell-and-tube heat exchanger, plate heat exchanger and double pipe heat exchanger. This work chooses the oil−water system and shell-and-tube heat exchanger. The tube-side fluid is municipal water, and the shell side fluid is heat transfer oil. The schematic diagram of test rig is shown in Fig. 1.

Figure 2 shows the photos of five tube bundles in the test helical baffle heat exchanger with incline angles of 12°, 16°, 20°, 24° and 28° and one tube bundle in the segmental baffled heat exchanger. The cylinder shell in the test rig can be shared by two kinds of heat exchanger and the tube bundles are replaceable. One-way counter- flow layouts are used in both shell and tube sides. The inner diameter of the shell is 81 mm, and the diameter of the baffles is 79 mm; the effective geometry (outer diameter×thickness×length) of the heat transfer tubes is 10 mm×l mm×832 mm. The number of heat transfer tubes is 16 and the tubes are equilateral triangularly arranged. There are also 3 sets of rods and spanning tubes to fix the baffles. The other geometric parameters are listed in Table 1. Figure 3 shows the projection view of baffles and the tube layout of helical heat exchangers (left) and segmental heat exchangers (right). In the circumferential overlap trisection helical baffle heat exchanger, the two straight edges of each baffle are widened and the baffle occupies more than one third cross sections, which makes the circumferential overlap area of the adjacent baffles be accommodated by a row of tubes for dampening reverse leakage. Both mass flow rate and volume flow rate of heating oil are measured with Emerson F025 mass flow meter (uncertainty ± 0.15%), while the volume flow rate of cooling water is measured with a turbo-flow-meter (uncertainty ± 0.5%). The temperature is measured with platinum resistance thermometers (uncertainty ± 0.15°C). And the shell side pressure drop is measured with a Rosemount 3051S differential pressure transmitter (uncertainty ± 0.15%). The temperature and pressure measuring points are

J. Cent. South Univ. (2016) 23: 2720−2727

2722

Fig. 1 Schematic diagram of heat transfer test rig: (a) Schematic diagram of oil-water test rig; (b) Photo of oil−water and water–water

test rig

Fig. 2 Photo of tube bundles of testing heat exchangers: (a) From left to right: 12°, 16°, 20°, 24°, 28° and seg; (b) From left to right:

28°, 24°, 20°, 16° ,12° and seg (sectional)

Table 1 Geometric parameters of testing helical and segmental

baffled heat exchangers

Item Inclined angle/(°) Baffle

number Helical

pitch/mm

cothSTHX

12 50 47.2

16 38 62.7

20 30 78.8

24 25 95.8

28 21 113.9

sgSTHX 0 10 75.5

arranged at the tubular bent conjunctions to the inlets and outlets of the testing heat exchanger. The experimental data were collected by an Agilent 34970A data acquisition instrument and processed by operation software programmed on the platform of LabVIEW.

3 Method and analysis 3.1 Experiment data process

During the oil-to-water performance tests, the flow rate of heat transfer oil was adjusted by changing the oil pump motor frequency from 25 Hz to 50 Hz by 5 Hz step with an inverter; and its inlet temperature was kept at 85 (±0.5) °C by a electric heater controlled with a solid state relay. The inlet temperature and the flow rate of cooling water in tube-side were kept at 11(±0.4) °C and 0.20 (±2.5%) kg/s (Reynolds number about 2000).

The heat exchanger overall heat transfer coefficient K can be obtained from the Eq. (1). Because of the heat exchanger is new, scale formation can be ignored. The flow of tube side heat transfer coefficient hi can be estimated by Eq. (2) [24], and the shell side heat transfer coefficient ho can be calculated by Eq. (3).

J. Cent. South Univ. (2016) 23: 2720−2727

2723

Fig. 3 Projection view of baffles and tube layout of helical heat exchangers (a) and segmental heat exchangers (b)

m

oi

2 tA

QQK

(1)

14.0

w

i3

1

iii

i

ii 86.1

l

dPrRe

dh (2)

i

oo

ii

oo

ln2

1

1

d

dd

hd

d

K

h

(3)

where Qi and Qo are are the transferring heat at tube-side and shell-side, respectively; A is the heat transfer area; Δtm is the logarithmic mean temperature difference; l is the length of heat exchange tube; do and di are the tube outer and inner diameters respectively; λ is the thermal conductivity of material of the tubes; μ is fluid dynamic viscosity.

Using dimensionless numbers to process the experiment data is significant for analyzing data, fitting formula of heat transfer and resistance, and the heat exchanger design. Because the shell-side Reynolds number Re0 demonstrates no additional merit but difficult in calculating the cross section of the helical channel, the shell-side axial Reynolds number Rez0 defined in Eq. (4) is used reasonably as the independent variable for comparing different schemes, which actually corresponds to the flow rate in the shell side and more fair to compare the performance of different schemes. Equation (5) reflects the relationship between Rez0 and the axial velocity w0. The shell-side Nusselt number Nu0 and the shell-side hydraulic diameter dh0 are respectively defined in Eqs. (6) and (7). For the similar reason that the friction factor is quite difficult to determine because of the complexity of flow in the helical channel, so the shell-side axial Euler number Euz0 is adopted and defined in Eq. (8) based on the Fanning formula to reflect the shell side flow friction factor of different baffle schemes. The shell side pressure drop can be calculated by the Eq. (8) as long as the shell-side axial Euler number Euz0 is obtained from the correlation equation. Therefore, this

paper uses comprehensive index Nu0·Rez0−1 to analyze

and compare the heat transfer capability of all heat exchanger schemes.

v

dwRe 00

0z (4)

)(π

42r

20

2s

00

ndNdD

Gw

(5)

0

000

hdhNu (6)

00

2

0

20

2

0 π

32

2/π

8/π4/34 d

d

a

d

dadh

(7)

200

00

2

wg

pEuZ

(8)

where G0 is the mass flow rate of the shell side; Ds, dr and a are the shell inner diameter, the spanning tube diameter and the tube pitch, respectively; N and n are the tube number and rod number in the radius of the shell, respectively. 3.2 Experimental error analysis

The experimental error of direct measurement parameters can transfer to the indirect ones. The direct measurement parameters include length and diameter of the heat exchanger, the fluid temperature and pressure of inlet and outlet, the flow rate of tube and shell side, and so on. And the direct measurement parameters include the quantity of heat transferred in tube-side and shell- side, the overall heat transfer coefficient and the heat transfer coefficient of shell side, and others.

The indirect experimental error of overall heat transfer coefficient K is estimated with Eq. (9).

222

mtAQK (9)

The indirect experimental error of the quantity of heat transferred Q is estimated with Eqs. (10) and (11).

J. Cent. South Univ. (2016) 23: 2720−2727

2724

oi QQQ (10)

0,

222,

ijtCGQ jjpjj

(11)

Through analyzing the main measuring instrument

accuracy of the test rig, the relative experimental error of direct measurement parameters of six heat exchanger schemes are shown in Table 2.

The relative experimental error of indirect measurement parameters of six heat exchanger schemes is obtained by the experimental error transfer theory are listed in Table 3.

Table 3 shows that the maximum relative experimental error of indirect measurement parameters is ±6.45%, thus the experiment data are effective and reliable. 4 Experimental results and discussions

As all the experiments were completed within the same shell and both the size and the number of the replaceable tube bundles are identical, the shell side flow rate G0 can be reasonably considered independent variable for comparing characteristics of different schemes.

Figures 4 to 7 show the curves of the overall h.t.c. K, the shell side h.t.c. ho, the shell side pressure drop Δpo and the comprehensive index of ho/Δpo varied with the shell side flow rate Go of oil-to-water heat transfer. From the figures it can be seen that the overall h.t.c. K, the

shell side h.t.c. ho and the shell side pressure drop Δpo increases with the increase of the shell side flow rate Go for all schemes. These parameters increase with the decrease of the baffle incline angle at a constant flow rate for helical schemes. The segmental baffled scheme has the lowest average values of overall h.t.c. and shell side h.t.c. and the second highest average value of shell side pressure drop. Within the testing scope,unlike other helical baffled schemes,12° curve of the overall h.t.c. K and the shell side h.t.c. ho have shape increase gradient at smaller flow rate Go and then rise slowly with the increase of flow rate Go. All of the values of 20° are very close to those of 24° correspondingly. As the flow rate is only changed with the frequency of the pump motor, it can be seen from the Fig. 6 that the flow rate increases but the pressure drop reduces somewhat with the increase of the incline angles at the same pump motor frequency. Figure 7 shows that the curves of the comprehensive index ho/Δpo of the 12° is highest, followed with 20°, 24° and 28° sequentially, and the segmental baffled scheme is lowest. The ratios of average values of overall h.t.c. K, shell side h.t.c. ho, pressure drops Δpo and comprehensive index ho·Δpo

−1 of the 12° helical baffled scheme over those of the segmental baffled scheme are 1.416, 1.664, 1.039 and 1.596, respectively. It shows that ho/Δpo decreases with the increase of the shell side flow rate for all schemes.

The results indicate that the smaller the baffle incline angle is, the higher the overall h.t.c., shell side h.t.c. and pressure drop of the testing helical baffle

Table 2 Direct measurement parameters’ relative experimental error of six kinds of heat exchangers

Angle/(°) Shell side inlet

temperature (To/To

)/%

Shell side outlet temperature (To/To

)/%

Shell side mass flow rate

(Go/Go)/%

Shell side pressure drop (Δpo/Δpo)/%

Tube side inlet temperature (Ti/Ti

)/%

Tube side outlet temperature (Ti/Ti

)/%

Tube side mass flow rate (Gi/Gi)/%

12 ±(0.21−0.22) ±(0.24−0.26) ±(0.15) ±(0.075) ±(1.37−1.38) ±(0.63−0.75) ±(0.5)

16 ±(0.21−0.22) ±(0.24−0.26) ±(0.15) ±(0.075) ±(1.29−1.33) ±(0.64−0.76) ±(0.5)

20 ±(0.21−0.22) ±(0.24−0.26) ±(0.15) ±(0.075) ±(1.30−1.33) ±(0.64−0.76) ±(0.5)

24 ±(0.21−0.22) ±(0.24−0.26) ±(0.15) ±(0.075) ±(1.37−1.43) ±(0.69−0.80) ±(0.5)

28 ±(0.21−0.22) ±(0.24−0.25) ±(0.15) ±(0.075) ±(1.39−1.43) ±(0.70−0.83) ±(0.5)

Seg ±(0.21−0.22) ±(0.24−0.26) ±(0.15) ±(0.075) ±(1.08−1.36) ±(0.62−0.87) ±(0.5)

Table 3 Indirect measurement parameters’ relative experimental error of six kinds of heat exchangers

Angle/(°) Shell side heat transfer

(Q1/Q1)/% Tube side heat transfer

(Q2/Q2)/% Average heat transfer

(Q/Q)/% Overall heat transfer coefficient (K/K)/%

12 ±(1.09−1.95) ±(1.50−1.92) ±(2.21−2.46) ±(3.86−5.18)

16 ±(1.13−2.02) ±(1.62−2.04) ±(2.33−2.59) ±(3.84−6.20)

20 ±(1.18−2.20) ±(1.61−2.06) ±(2.37−2.73) ±(4.10−5.32)

24 ±(1.39−2.20) ±(1.67−2.19) ±(2.49−2.76) ±(4.60−6.45)

28 ±(1.31−2.38) ±(1.73−2.27) ±(2.58−2.94) ±(4.47−5.81)

Seg ±(1.32−2.30) ±(1.74−2.52) ±(2.74−2.89) ±(4.16−5.87)

J. Cent. South Univ. (2016) 23: 2720−2727

2725

Fig. 4 Overall heat transfer coefficient versus shell side flow

rate

Fig. 5 Shell side heat transfer coefficient versus shell side flow

rate

Fig. 6 Shell side pressure drop versus shell side flow rate

schemes are. The shell side h.t.c. ho and comprehensive index ho·Δpo

−1 of the 12° helical scheme are above 50% higher than those of the segmental baffled scheme correspondingly, while the pressure drop is very close, which are attractively indicating the superior features of the cothSTHXs. The results also indicated that it is unnecessary for cothSTHXs to deliberately pursue large baf f le inc l ine ang le wi th g rea te r d i f f i cu l ty in

Fig. 7 Comprehensive index of ho·Δpo

−1 versus shell side flow

rate

manufacturing helical baffles for small volumetric liquid fluids.

Figure 8 shows the shell side heat transfer coefficient ho versus shell side pressure drop Δpo of six schemes. The ho−Δpo curve is often used to compare comprehensive performance of heat exchangers. It shows that the change regulation of shell side h.t.c. ho versus the shell side pressure drop Δpo in all schemes is the same with those in Fig. 7.

Fig. 8 Shell side heat transfer coefficient versus shell side

pressure drop of six schemes

Figures 9 and 10 show the regulation that the shell side axial Euler number Euz0 and the shell side Nusselt number Nu0 change with the shell side axial Reynolds number Rez0. Unlike the linear-like increasing curves of Nusselt number, each curve of Euler number has shaped decrease gradient at smaller axial Reynolds number and then falls slower with the increase of axial Reynolds number. Figure 11 shows the comprehensive index of Nu0·Rez0

−1 varies with the shell side axial Reynolds number Rez0 of these schemes. The positive proportional trend of the curves of comprehensive index Nu0·Rez0

−1 versus Reynolds number is quite different from that of the decreased trend of the comprehensive index ho·Δpo

−1

J. Cent. South Univ. (2016) 23: 2720−2727

2726

Fig. 9 Shell side Nusselt numbers versus shell side axial

Reynolds number

Fig. 10 Shell side axial Euler numbers versus shell side axial

Reynolds number

Fig. 11 Comprehensive indexes Nu0·Euz0

−1 versus shell side

axial Reynolds number

versus shell side flow rate as shown in Fig. 7. The above test results show that the best incline

angle for the circumferential overlap trisection helical baffle heat exchangers with small shell side flow rate (such as oil cooler) is around 12°. Small incline angle scheme not only has the highest heat transfer coefficient and the highest comprehensive evaluation index, but also

easy to manufacture. However, whether this conclusion is suitable for larger volume flow rate or larger size heat exchangers has yet to be confirmed by further studies. 5 Conclusions

1) The testing schemes on oil−water test rig include five circumferential overlap trisection helical baffle heat exchangers (cothSTHXs) with incline angles of 12°, 16°, 20°, 24°, 28° and a segmental baffled one. Incline angle of baffle has important influence on the heat transfer performance of cothSTHXs.

2) The heat transfer performance test results are presented including both overall h.t.c. K and shell-side h.t.c. ho, pressure drop Δpo and the comprehensive index ho·Δpo

−1 vary with the shell side flow rate. In the testing scope, the small angled helical scheme demonstrates better performance that the shell side heat transfer coefficient ho and comprehensive index ho·Δpo

−1 of the 12° helical scheme are about 66.4% and 59.6% higher than those of the segmental baffled one with approximate pressure drop, which also verifies the superior heat transfer features of the cothSTHXs.

3) The regulation that the shell side axial Euler number Euz0, the shell side Nusselt number Nu0 and the comprehensive index Nu0·Euz0

−1 change with the shell side axial Reynolds number Rezo are studied. In the testing scope, the shell-side Nusselt number Nu0 and the comprehensive index Nu0·Euz0

−1 increase with the increase of the shell side axial Reynolds number for all cothSTHXs and demonstrate that the small inclined angle helical scheme has better performance.

References [1] YOU Yong-hua, FAN Ai-wu, HUANG Su-yi, LIU Wei. Numerical

modeling and experimental validation of heat transfer and flow

resistance on the shell side of a shell-and-tube heat exchanger with

flower baffles [J]. International Journal of Heat and Mass Transfer,

2012, 55: 7561−7569.

[2] YOU Yong-hua, FAN Ai-wu, LAI Xue-jiang, HUANG Su-yi, LIU

Wei. Experimental and numerical investigations of shell-side thermo-

hydraulic performances for shell-and-tube heat exchanger with

trefoil-hole baffle [J]. Applied Thermal Engineering, 2013, 50:

950−956.

[3] LUTCHA J, NEMCANSKY J. Performance improvement of tubular

heat exchangers by helical baffles [J]. Chemical Engineering

Research & Design, 1990, 68(3): 263−270.

[4] JAFARI N M R, SHAFEGHAT A. Fluid flow analysis and extension

of rapid design algorithm for helical baffle heat exchangers [J].

Applied Thermal Engineering, 2008, 28(11/12): 1324−1332.

[5] STEHLIK P, NEMCANSKY J, KRAL D. Comparison of correction

factors for shell-and-tube heat exchangers with segmental or helical

baffles [J]. Heat Transfer Engineering, 1994, 15(1): 55−65.

[6] STEHLIK P, WADEKAR V. Different strategies to improve

industrial heat exchange [J]. Heat Transfer Engineering, 2002, 23(6):

36−48.

J. Cent. South Univ. (2016) 23: 2720−2727

2727

[7] SUN Qi, CHEN Jia-jia, ZHU Ying, WANG Hai-xiu, WANG Shu-li.

Hydrodynamic studies on the shells of the heat exchangers with

overlap helical baffles [J]. Chemical Engineering & Machinery, 2008,

35(1): 10−13. (in Chinese)

[8] WANG Liang, LUO Lai-qin, WANG Qiu-wang, ZENG Min, TAO

Wen-quan. Effect of inserting block plates on pressure drop and heat

transfer in shell-and-tube heat exchangers with helical baffles [J].

Journal of Engineering Thermo Physics, 2001, 22(Suppl): 173−176.

(in Chinese)

[9] ZENG Min, PENG Bo-tao, YU Peng-qing,CHEN Qiu-yang, WANG

Qiu-wang, HUANG Yan-ping, XIAO Zhe-jun. Experimental study of

heat transfer and flow resistance characteristics for shell-and-tube

heat exchangers with continuous helical baffles [J]. Nuclear Power

Engineering, 2006, 27(Suppl): 102−106. (in Chinese)

[10] WANG Qiu-wang, CHEN Qiu-yang, CHEN Gui-dong, ZENG Min.

Numerical investigation on combined multiple shell-pass shell-and-

tube heat exchanger with continuous helical baffles [J]. International

Journal of Heat and Mass Transfer, 2009, 52(5/6): 1214−1222.

[11] WANG Qiu-wang, ZENG Min, MA Ting, DU Xue-ping, YANG

Jian-feng. Recent development and application of several high-

efficiency surface heat exchangers for energy conversion and

utilization [J]. Applied Energy, 2014, 135: 748−777.

[12] JI Shui, DU Wen-jing, CHENG Lin. Numerical studies on double

shell-pass heat exchanger with continuous helical baffles [J]. Journal

of Engineering Thermo Physics, 2010, 31(4): 651−654. (in Chinese)

[13] JI Shui, DU Wen-jing, WANG Peng, CHENG Lin. Field synergy

analysis on shell-side flow and heat transfer of heat exchanger with

staggered overlap helical baffles [J]. Proceedings of the CSEE, 2011,

31(20): 75−79. (in Chinese)

[14] SONG Xiao-ping, PEI Zhi-zhong. Shell and tube heat exchanger

with anti-short circuit spiral baffle plate [J]. Petro-Chemical

Equipment Technology, 2007, 28(3): 13−17. (in Chinese)

[15] LIN Yu-juan, LIU Dan, YANG Xiao-bo, LI Lei-peng. Study on the

best spiral angle of helical baffle heat exchanger based on htri

software [J]. Science Technology and Engineering, 2012, 12(5):

1181−1184. (in Chinese)

[16] CHEN Ya-ping, SHENG Yan-jun, DONG Cong, WU Jia-feng.

Numerical simulation on flow field in circumferential overlap

trisection helical baffle heat exchanger [J]. Applied Thermal

Engineering, 2013, 50(1): 1035−1043.

[17] DONG Cong, CHEN Ya-ping. Impact of block plates on the flow and

heat transfer performance of middle-axial-overlap helical baffle heat

exchangers [J]. Journal of Mechanical Engineering, 2014, 50(6):

135−140. (in Chinese)

[18] WANG Wei-han, CHEN Ya-ping, CAO Rui-bing, SHI Ming-heng.

Analysis of secondary flow in shell-side channel of trisection helix

heat exchangers [J]. Journal of Southeast University: English Edition,

2010, 26(3): 426−430.

[19] DONG Cong, CHEN Ya-ping, WU Jia-feng. Comparison of heat

transfer performances of helix baffled heat exchangers with different

baffle configurations [J]. Chinese Journal of Chemical Engineering,

2015, 23: 255−261.

[20] WANG Si-min, WEN Jian. Experiment on heat transfer performance

of helical baffled heat exchanger without short circuit flow [J].

Journal of Xi’an Jiaotong University, 2012, 46(9): 12−15, 42. (in

Chinese)

[21] WEN Jian, YANG Hui-zhu, WANG Si-min, XU Shi-feng, XUE

Yu-lan, TUO Han-fei. Numerical investigation on baffle

configuration improvement of the heat exchanger with helical baffles

[J]. Energy Conversion and Management, 2015, 89: 438−448.

[22] DU Wen-jing, WANG Hong-fu, CAO Xing, CHENG Lin. Heat

transfer and fluid flow on shell-side of heat exchangers with novel

sextant sector helical baffles [J]. CIESC Journal, 2013, 64(9):

3123−3129. (in Chinese)

[23] GAO Xing, DU Wen-jing, CHENG Lin. Performance of heat

exchanger with novel overlapped helical baffles [J]. Journal of

Engineering Thermo Physics, 2013, 34(6): 1130−1132. (in Chinese)

[24] YANG Shi-ming, TAO Wen-quan. Heat transfer [M]. Fourth Edition.

Beijing: Higher Education Press, 2006: 251−252. (in Chinese)

(Edited by DENG Lü-xiang)