(Luận văn thạc sĩ hcmute) nghiên cứu thực nghiệm quá trình bay hơi của nước cấp lò hơi trong kênh micro

BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH LUẬN VĂN THẠC SĨ NGUYỄN HUY VŨ NGHIÊN CỨU THỰC NGHIỆM QUÁ TRÌNH BAY HƠI CỦA NƯỚC CẤP LỊ HƠI TRONG KÊNH MICRO NGÀNH: KỸ THUẬT NHIỆT – 8520115 SKC007276 Tp Hồ Chí Minh, tháng 05/2021 Luan van BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH LUẬN VĂN THẠC SĨ NGUYỄN HUY VŨ NGHIÊN CỨU THỰC NGHIỆM QUÁ TRÌNH BAY HƠI CỦA NƯỚC CẤP LÒ HƠI TRONG KÊNH MICRO NGÀNH: KỸ THUẬT NHIỆT – 8520115 Tp Hồ Chí Minh, tháng 5/2021 Luan van BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH LUẬN VĂN THẠC SĨ NGUYỄN HUY VŨ NGHIÊN CỨU THỰC NGHIỆM Q TRÌNH BAY HƠI CỦA NƯỚC CẤP LỊ HƠI TRONG KÊNH MICRO NGÀNH: KỸ THUẬT NHIỆT – 8520115 Hướng dẫn khoa học: PGS.TS ĐẶNG THÀNH TRUNG LÝ LỊCH KHOA HỌC Tp Hồ Chí Minh, tháng 5/2021 Luan van QUYẾT ĐỊNH GIAO ĐỀ TÀI i Luan van ii Luan van iii Luan van iv Luan van v Luan van vi Luan van vii Luan van [33] Batan Le, Vanmanh Nguyen, and Thanhtrung Dang, “The Effects of Inlet Temperature on Heat Transfer Behaviours of Evaporation in Rectangular Microchannels”, International Journal of Innovative Science, Engineering & Technology, 2017, Vol [34] Thanhtrung Dang, Jyh-Tong Teng, “Comparisons of the heat transfer and pressure dropof the microchannel and minichannel heat exchangers ”, Heat Mass Transfer, 2011, 1311–1322 [35] Thanhtrung Dang, Hoangtuan Nguyen, Giadat Nguyen, “Experimental Investigations for Fluid Flow Characteristics of Refrigerant R134a in a Microtubes Evaporator”, International Conference on Green Technology and Sustainable Development (GTSD), 2018 [36] Kimhang Vo, Thanhthao Nguyen, Thanhtrung Dang, Tronghieu Nguyen, Hoangtuan Nguyen, “An Experimental Investigation on the Heat Transfer Coefficient of CO2 in Minichannel and Microchannel Evaporators”, International Conference on “Physics and Mechanics of New Materials and Their Applications” PHENMA, 2019 [37] Congkhanh Le, Thanhtrung Dang, Batan Le, Kiencuong Giang, “The Comparisons OnDistribution Between Perpendicular Flow And Parallel Flow Of Microchannel Evaporators By The Separated Manifolds”, Mechanics, Materials Science & Engineering, 2018, 2412-5954 [38] Nguyễn Tấn Sa, “ Ảnh hưởng lưu lượng nhiệt độ đến truyền nhiệt tổn thất áp suất trình bay kênh micro”, ngày 19 tháng 09 năm 2016, ĐH Sư Phạm Kỹ Thuật TP.HCM [39] Nguyễn Văn Mạnh, “Nghiên cứu ảnh hưởng hình dáng hình học đến q trình bay kênh micro cho dịng chảy hai pha”, ngày 19 tháng 09 năm 2017, ĐH Sư Phạm Kỹ Thuật TP.HCM 64 Luan van [40] Nguyễn Ngọc Sang, “Nghiên cứu ảnh hưởng hình dáng hình học đến trình bay kênh micro cho dòng chảy hai pha”, ngày 04 tháng 04 năm 2019, ĐH Sư Phạm Kỹ Thuật TP.HCM [41] PGS.TS Hoàng Đình Tín, “Cơ sở truyền nhiệt thiết kế thiết bị trao đổi nhiệt”, nhà xuất Đại học quốc gia TP.HCM năm 2013 [42] Yunus A Cengel, “Internal Forced Convection”, in Heat Transfer: A Practical Approach, 2nd end New York: McGraw –Hill, 2002, pp 419-440 [43] S.Kandlikar, S.Garimella, D.Li, S.colin, M.R.King, “Heat transfer and fluid flow in minichannels and microchannels”, Elsevier Internet Homepage, 2006 [44]https//vi.wikipedia.org/wiki/Th%C3%A0nh_ph%E1%BB%91_H%E1%B% 93_Ch%C3%AD_Minh 65 Luan van PHỤ LỤC 66 Luan van 67 Luan van 68 Luan van 69 Luan van 70 Luan van EXPERIMENTAL INVESTIGATION ON PRESSURE DROP AND HEAT TRANSFER BEHAVIORS OF THE MICROCHANNEL EVAPORATORS USING THE BOILER FEED WATER Thanhtrung Dang Huyvu Nguyen Batan Le Jyh-tong Teng Department of Thermal Department of Thermal Department of Thermal Department of Engineering, Engineering, Engineering, Mechanical Engineering, HCMC University of HCMC University of HCMC University of Chung Yuan Christian Technology and Technology and Technology and University, Chungli City, Education Education Education Taiwan HCM City, Vietnam HCM City, Vietnam HCM City, Vietnam trungdang@hcmute.edu.vn ks.nguyenhuyvu@gmail.com lebatan@hcmute.edu.vn jtteng1@gmail.com Abstract–In this study, the pressure drop and heat transfer making a deeply research related to microchannel heat behaviors of the microchannel evaporators using the exchangers, boiler feed water were investigated experimentally The evaporators Regarding to this field, Li et al [1] physical and chemical components of the boiler feed investigated in single-phase heat transfer and flow water were also determined for this case study The characteristics of microchannels with microribs The results of the pressure drop obtained from two results showed that the Nusselt number increases with measurement methods are the same, with the maximum increasing of volumetric flow rate and inlet temperature percentage error is less than 3% At the low flow rate, the Besides, the friction factor decreases with increasing of microchannel evaporator with short channel length has inlet temperature In addition, they also showed that the lower pressure drop; however, this evaporator has higher thermal pressure drop at the high flow rate The experimental data microchannels with rectangular ribs on one side was above are essential for designing the microchannel higher than those of the smooth rectangular microchannel evaporators and the rectangular microchannels with rectangular ribs especially performance with index the of the microchannel rectangular on both sides Keywords - Heat transfer rate, pressure drop, boiler feed water, evaporation, water hardness, microchannel Yin et al [2] studied in the heat transfer and pressure drop characteristics of water flow boiling in open microchannels using deionized (DI) water as a working I INTRODUCTION fluid The results showed that the small size - open One of the most interesting topics in this decade is microchannel with a great number of channels gives a energy saving and environmental protection Compacting better heat dissipation capability and a higher pressure and intergrating are the primary tasks for getting higher drop in stratified flow regimes The fluid flow and heat heat transfer efficiency Therefore, it is very necessary to transfer characteristics of double-layer microchannel heat learn about pressure drop and heat transfer behaviors by exchanger are investigated by Zhou et al [3] The results Luan van indicated that the microchannel heat exchanger with the [8] The results indicated that larger channel diameter and height of 1-1.5mm, the width of 0.4-0.6mm and 0.6- longer channel length show less flow reversal with a 0.8mm lower frequency Foo et al [9] studied in the single-phase in spacing shows better heat exchange performance Jia et al [4] studied on the comparison of convective flow drop microchannels by using macro geometry and distilled characteristics in porous-wall microchannel heat sink with water as the working fluid The results showed that the the working fluid of pure acetone liquid The results microchannels with higher wave amplitudes and shorter showed that comparing to the conventional rectangular wavelengths give better heat transfer performance microchannel heat sink, the porous-wall microchannel Besides, the enhanced microchannel is capable of heat sink has better critical heat flux Besides, the porous- removing 51% heat comparing to the plain annular wall microchannel heat sink reduces the pressure drop channel, at a given pumping power Markal et al [10] and gives significant enhancement on heat transfer focused on the heat transfer and the pressure drop of the Rostami et al [5] focused on conjugate heat transfer in saturated flow boiling in square microchannels The wavy walls microchannels with different geometrical results showed that the local two phase heat transfer parameters for searching the optimum geometry with the coefficient decreases with increasing of heat flux largest Nusselt number The results indicated that the Whereas, the total pressure drop increases with increasing Nusselt number in wavy microchannel is larger than the of heat flux; however, pressure drop generally decreases one of flat walls microchannels Besides, there is an with increasing the mass flux for a constant heat flux The optimum geometry for wavy walls in opposite of flat effect of surface roughness on the hydrodynamic and walls microchannels, which give the largest Nusselt thermal performance of microchannel evaporators was number studied by Jafari et al [11] The results showed that the boiling heat transfer and pressure heat transfer performance of wavy Col et al [6] measured the heat transfer coefficients two-phase heat transfer coefficient is capable of during flow boiling of HFC-134a and HFC-32 in single increasing up to 45% with increasing surface roughness at circular channel The results showed that R134a shows low to moderate heat flux Abdollahi et al [12] studied on lower saturation and higher pressure than R32 In the fluid flow and heat transfer of liquid-liquid Taylor addition, the heat transfer coefficient of R134a and R32 flow in a square microchannel The results indicated that depend on the heat flux strongly; however, it does not liquid-liquid Taylor flow is capable of increasing the rate depend on the mass flux Besides, the heat transfer of heat transfer up to 700 % comparing to that single coefficients rise with the rising of heat flux in the phase flow Besides, the friction factor decreases with saturated region Morshed et al [7] studied in the effect of increasing of the Reynolds Number from to 100 the Al2O3 nanoparticle deposition on flow boiling From the literature reviews above, the deionized performance of deionized water in a single microchannel water and several refrigerants were used as the working The experiments were carried out in a copper fluid to investigate The effects of the physical and microchannel coated with Al2O3 nanoparticle The results chemical components of several types of water on showed that the heat transfer coefficient reduces evaporation in microchannel heat sinks did not mention marginally, the critical heat flux increases up to 39% for clearly, especially with the boiler feed Therefore, it is the nanoparticles coated surface comparing to the bare important to experiment a case study on pressure drop surface The effect of channel geometry on flow reversal and heat transfer phenomena of microchannel evaporators in microchannel evaporators was investigated by Li et al using the boiler feed water Luan van II METHODOLOGY A and specific heat maintained at a constant pressure of 904 Structure design J/(kgK) The governing equations were used as follows: Based on the scope of the study, three types of The evaporative heat transfer rate was calculated as: Q = m × (h2 – h1), W Aluminum microchannel evaporators were designed and manufactured with the evaporative capacity around 250W Fig.1 shows the dimensions of these microchannel For the sensible heat, the evaporative heat transfer rate was calculated as: Q = m × cp × (T2 – T1), W evaporators These three samples are almost the same, only with a different channel length, as shown in Table The pressure drop was determined as: p = p2 – p1, Pa and Fig.2 where cp is specific heat at constant pressure, m is mass flow rate (kg/s), h is enthalpy (kJ/(kg.K), p is pressure (Pa), and T is temperature (K) The subscripts: stands for inlet and stands for outlet B Experimental Setup The schematic diagram of the test loop is shown in Fig The microchannel evaporator was heated on two surfaces by two resistors Each resistor has the power input of 150 W The Fig.4 shows the real photo of the system The accuracy of parameters is listed in Table There are some devices were used for experimental setup: Figure Dimensions of the microchannel evaporators Temperature sensors: T – types Infrared thermometer, Raynger@ST, made by Raytek Thermal camera, Fluke Ti9, made by Fluke, USA Pumps: PU-2087, manufactured by Jasco Heater: AXW-8, manufactured by Medilab Pressure sensor: made by SENSYS, Korea Figure Three types of microchannel evaporators Difference pressure transducer: PMP4110, manufactured by Duck Electric balance: TE-214S, manufactured by Sartorious Table Summary of microchannel dimensions Sample Length (mm) Width (mm) Thickness (mm) A B C 140 160 180 14 14 14 2.2 2.2 2.2 Hydraulic diameter (mm) 0.9 0.9 0.9 Aluminum was used for the substrate with a thermal conductivity of 237 W/(mK), a density of 2,700 kg/m3, Figure Schematic diagram of the test loop Luan van Table Accuracy of parameters Parameters Temperature Thermal camera Infrared thermometer Pressure Pressure drop Mass flow rate Power meter 3.1 The experimental results for the sample A Tolerance ± 0.1 °C 2%  C of reading ± 0.05% FS ± 0.04% FS ± 0.0015 g ± 0.01% From experimental data for the sample A, with the inlet water temperature of 40 °C, the resistor power for evaporation is 150 W at the mass flow rate of 0.04 g/s and the resistor power for evaporation is 299 W at the mass flow rate of 0.1 g/s It is indicating that the resistor power increases as increasing the mass flow rate When the mass flow rate increases from 0.04 g/s to 0.1 g/s, the pressure drop (1) obtained from the two pressure sensors increases from 687 Pa to 1687 Pa while the pressure drop (2) obtained from the difference pressure transducer increases from 707 Pa to 1707 Pa The maximum difference of the pressure drop between two measument methods is 20 Pa, with the maximum percentage error is less than 3% This Figure A photo of the test loop has shown that the experimental pressure drop results in In this case study, the boiler feed water has the this study are reliable, as shown in Fig chemical and physical components: DO (Dissolved Oxygen) is 7.04 mgO2/L; NTU (Nephelometric Turbidity Unit) is 0; PH (Power of Hydrogen) is 8.7; water hardness is 22 mgCaCO3/L; and TDS (Total Dissolved Solids) is 0.6 ppm The TDS number in this study is met with the ABMA (American Boiler Manufacturers Association) standards The pressure drops for these evaporators were determined experimentally for two measurement methods to double check: The pressure drop was determined by Figure The pressure drop vs the mass flow rate for the two pressure sensors at the heads of the evaporator and sample A the pressure drop was determined by a difference With the same flow rate condition, when the inlet water temperature is changed from 40 C to 60 C, the pressure transducer heat transfer rate of evaporation is reduced This rule was III RESULTS AND DISCUSSION achieved for the rising of the mass flow rate from 0.04 g/s Experimental data obtained from the microchannel to 0.1 g/s At the inlet water temperature of 40 C, the evaporators are under the constant room temperature heat transfer rate of evaporation increases from 103.6 W condition of 29 °C The mass flow rate of the boiler feed to 252.8 W as increasing the mass flow rate from 0.04 g/s water is changing from 0.04 g/s to 0.1 g/s The inlet water to 0.1 g/s However, at the same flow rate of 0.04g/s, the temperature is changing from 40 °C to 60 °C The outlet heat transfer rate is reduced from 103.6 W to 100.9 W steam temperature is kept at 107 °C With the outlet when the inlet water temperature increases from 40 C to steam pressure is less than 102800 Pa, its state is 60 C, as shown in Fig This phenomenon is due to the superheated Luan van inlet water temperature increases, the Enthalpy increases, leading to the heat transfer rate for evaporation decreases if the outlet steam condition is constant Figure The heat transfer rate of evaporation for the sample B Figure The heat transfer rate of evaporation for the sample A 3.3 The experimental results for the sample C As the same rule with the sample A and the sample B, the 3.2 The experimental results for the sample B Fig shows a relationship between the pressure drop and From experimental data for the sample B, with the inlet the mass flow rate of the sample C at the inlet water water temperature of 40 °C, the resistor power for temperature of 40 oC When the mass flow rate increases evaporation is 160 W at the mass flow rate of 0.04 g/s from 0.04 g/s to 0.1 g/s, the pressure drop increases from The Fig shows a relationship between the pressure drop 1000 Pa to 1395 Pa The results of the pressure drop and the mass flow rate of the sample B at the inlet water obtained from two measurement methods are also the temperature of 40 oC When the mass flow rate increases same for sample C From three figures (Fig 5, Fig 7, and from 0.04 g/s to 0.1 g/s, the pressure drop increases from Fig 9), it is observed that at the low flow rate, the 948 Pa to 1473 Pa The results of the pressure drop evaporator with short channel length has lower pressure obtained from two measurement methods are the same for drop; however, this evaporator has higher pressure drop at sample B The evaporative heat transfer rate of the sample the high flow rate It is due to the effects of the heat B is shown in Fig At the inlet water temperature of 40 transfer from the resistor to the fluid flow C, the heat transfer rate of evaporation increases from 107 W to 257.8 W as increasing the mass flow rate from 0.04 g/s to 0.1 g/s Figure The pressure drop vs the mass flow rate for the sample C The evaporative heat transfer rate of the sample C is shown in Fig 10 From three figures (Fig 6, Fig 8, and Figure The pressure drop vs the mass flow rate for the sample B Fig 10), it is indicated that the sample A has the most stable heat for evaporation Besides, using the same the Luan van resistor, the inlet water temperature, and the mass flow ACKNOWLEDMENTS rate, the sample A has lowest resistor power The The supports of this work by the project No B2020-SPK- experimental data above are essential to verify the results 04 (sponsored by the Vietnam Ministry of Education and of the numerical simulation, making an important Training) are deeply appreciated contribution for designing the microchannel evaporator REFERENCES [1] Juan Li, Zhangyu Zhu, Liang Zhao, Hao Peng, “Experimental investigation of the heat transfer and flow characteristics of microchannels with microribs”, International Journal of Heat and Mass Transfer, 2019, Volume 143, 118-482 [2] Liaofei Yin , Peixue Jiang , Ruina Xu , Haowei Hu , Li Jia, “Heat transfer and pressure drop characteristics of water flow boiling in open microchannels”, International Journal of Heat and Mass Transfer, 2019, 204–215 [3] Fang Zhou, Wei Zhou, Qingfu Qiu, Wei Yu, Xuyang Chu, Figure 10 The heat transfer rate of evaporation for the sample C “Investigation of Fluid Flow and Heat Transfer Characteristics of Parallel Flow Double-Layer Microchannel Heat Exchanger”, Applied Thermal Engineering, 2018, S1359-4311 [4] Y.T Jia, G.D Xia, L.X Zong, D.D Ma, Y.X Tang, “A comparative study of experimental flow boiling heat transfer and pressure drop IV CONCLUSION The pressure drop and heat transfer behaviors of the characteristics in porous-wall microchannel heat sink”, International Journal of Heat and Mass Transfer, 2018, 818–833 microchannel evaporators using the boiler feed water [5] Javad Rostami, Abbas Abbassi, Majid Saffar-Avval, “Optimization of have investigated experimentally The physical and conjugate heat transfer in wavy walls microchannels”, Applied Thermal chemical components of the boiler feed water were also Engineering 82, 2015, 318-328 [6] Davide Del Col, Stefano Bortolin, Luisa Rossetto, “Convective determined for this case study The results of the pressure boiling inside a single circular microchannel”, International Journal of drop obtained from two measurement methods are the Heat and Mass Transfer, 2013, 1231–1245 same, with the maximum percentage error is less than [7] A.K.M.M Morshed, Titan C Paul, Jamil A Khan, “Effect of Al2O3 nanoparticle deposition on flow boiling performance of water in a 3% microchannel”, Experimental Thermal and Fluid Science, 2013, 6–13 At the low flow rate, the microchannel evaporator with [8] Huize Li, Pega Hrnjak, “Effect of channel geometry on flow reversal short channel length has lower pressure drop; however, in microchannel evaporators”, International Journal of Heat and Mass this evaporator has higher pressure drop at the high flow Transfer, 2017, 1–10 [9] Zi Hao Foo, Kai Xian Cheng, Aik Ling Goh, Kim Tiow Ooi, “Single- rate Some typical results for the sample A at the inlet phase convective heat transfer performance of wavy microchannels in water temperature of 40 C and the outlet steam macro geometry”, Applied Thermal Engineering, 2018, S1359-4311 temperature of 107 C: when the mass flow rate increases [10] Burak Markal, Orhan Aydin, Mete Avci, “An experimental investigation of saturated flow boiling heat transfer and pressure drop in from 0.04 g/s to 0.1 g/s, the pressure drop increases from square microchannels”, International Journal of Refrigeration, 2015, 707 Pa to 1707 Pa and the heat transfer rate of S0140-7007 evaporation increases from 103.6 W to 252.8 W also In addition, the experimental results are valuable for [11] Rahim Jafari, Tuba Okutucu-Ozyurt, Hakkı Özgür Ünver, Özgür Bayer, “Experimental Investigation of Surface Roughness Effects on the Flow Boiling of R134a in Microchannels”, Experimental Thermal and calculating design and numerical simulation of the Fluid Science, 2016, S0894-1777 microchannel evaporators [12] Ayoub Abdollahi, Stuart E Norris, Rajnish N Sharma, “Fluid Flow and Heat Transfer of Liquid-Liquid Taylor Flow in Square Microchannels”, Applied Thermal Engineering, 2020, S1359-4311 Luan van Luan van Luan van ... HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH LUẬN VĂN THẠC SĨ NGUYỄN HUY VŨ NGHIÊN CỨU THỰC NGHIỆM QUÁ TRÌNH BAY HƠI CỦA NƯỚC CẤP LÒ HƠI TRONG KÊNH MICRO NGÀNH: KỸ THUẬT NHIỆT – 8520115 Hướng dẫn... Tôi cam đoan luận văn thạc sĩ ? ?Nghiên cứu thực nghiệm trình bay nước cấp lị kênh Micro? ?? cơng trình nghiên cứu tơi Các số liệu, kết nêu luận văn trung thực chưa công bố cơng trình khác Tp Hồ Chí... HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH LUẬN VĂN THẠC SĨ NGUYỄN HUY VŨ NGHIÊN CỨU THỰC NGHIỆM QUÁ TRÌNH BAY HƠI CỦA NƯỚC CẤP LỊ HƠI TRONG KÊNH MICRO NGÀNH: KỸ THUẬT NHIỆT – 8520115 Tp Hồ Chí