This page has only limited features, please log in for full access.
Evaporative pre-cooling technology improves the cooling performance of natural draft dry cooling towers (NDDCTs) by introducing a certain amount of water into the air entrance. This paper compares the effects of different evaporative pre-cooling systems (i.e., normal wet-medium arrangement, A-frame wet-medium arrangement and nozzle spray) on the cooling performance of a 167 m high NDDCT. Based on the meteorological data of Naomao lake in Xinjiang in 2015, two MATLAB programs were developed for case studies. This study finds all the evaporative pre-cooling systems can improve the NDDCT's cooling performance in high temperature period. In non-high temperature period, the NDDCT's performance improvement is unremarkable, and the NDDCT's cooling performance even deteriorates in the case of evaporative pre-cooling using wet medium. In the hottest month of July, the water outlet temperatures of the NDDCT pre-cooled with normal wet-medium arrangement, A-frame wet-medium arrangement and nozzle spray drop 3.2 K, 3.5 K and 3.3 K, respectively when compared with no pre-cooling counterpart. The annual average water consumption values are 39.0 kg/s, 56.4 kg/s and 124.1 kg/s, respectively. Considering all the year around performance improvement, it is suggested to use nozzle spray pre-cooling system while intermittent operation or certain-time period operation should be considered to save water.
Jiayu Miao; Suoying He; Yuanwei Lu; Yuting Wu; Xuehong Wu; Guanhong Zhang; Ming Gao; Zhe Geng; Shuzhen Zhang. Comparison on cooling performance of pre-cooled natural draft dry cooling towers using nozzles spray and wet medium. Case Studies in Thermal Engineering 2021, 27, 101274 .
AMA StyleJiayu Miao, Suoying He, Yuanwei Lu, Yuting Wu, Xuehong Wu, Guanhong Zhang, Ming Gao, Zhe Geng, Shuzhen Zhang. Comparison on cooling performance of pre-cooled natural draft dry cooling towers using nozzles spray and wet medium. Case Studies in Thermal Engineering. 2021; 27 ():101274.
Chicago/Turabian StyleJiayu Miao; Suoying He; Yuanwei Lu; Yuting Wu; Xuehong Wu; Guanhong Zhang; Ming Gao; Zhe Geng; Shuzhen Zhang. 2021. "Comparison on cooling performance of pre-cooled natural draft dry cooling towers using nozzles spray and wet medium." Case Studies in Thermal Engineering 27, no. : 101274.
To enhance the thermal performance and relieve the impact of crosswind on the super large-scale natural draft wet cooling towers (SLWCTs), based on our previous research, through the three-dimensional numerical simulation of the SLWCT equipped with an axial fan, the impact of the fan positions on the thermal performance was investigated at various crosswind velocities (1–9 m/s) when the fan power was fixed to 200 kW. It is obtained that the optimized fan diameter and the installation height are 20 m and 18 m. Additionally, the characteristics of the aerodynamic and temperature field inside the tower with different fan positions were discussed based on the above results, subsequently, the change rules of water temperature drop, evaporation loss, and heat transfer coefficient are analyzed. The results manifested that the optimization scheme efficiently relieves the adverse effects of the crosswind, and the air velocity near the fan is significantly increased. By comparison with the case of no fan, the heat transfer coefficient and water temperature drop increase by 4.79% and 0.226 °C, respectively, and the evaporation loss increases by 2.86% at the utmost.
Deying Zhang; Rui Chen; Zhengqing Zhang; Suoying He; Ming Gao. Crosswind influence on heat and mass transfer performance for wet cooling tower equipped with an axial fan. Case Studies in Thermal Engineering 2021, 27, 101259 .
AMA StyleDeying Zhang, Rui Chen, Zhengqing Zhang, Suoying He, Ming Gao. Crosswind influence on heat and mass transfer performance for wet cooling tower equipped with an axial fan. Case Studies in Thermal Engineering. 2021; 27 ():101259.
Chicago/Turabian StyleDeying Zhang; Rui Chen; Zhengqing Zhang; Suoying He; Ming Gao. 2021. "Crosswind influence on heat and mass transfer performance for wet cooling tower equipped with an axial fan." Case Studies in Thermal Engineering 27, no. : 101259.
To improve the heat and mass transfer performance of large wet cooling towers, a synergetic optimization method of non-equidistant fillings and non-uniform water distribution was proposed in this paper. The impact of the optimization scheme on the cooling performance was studied for the cooling tower equipped for a 600 MW unit. Firstly, the fillings were divided into two zones, and the optimized inner fillings radius was obtained according to the different non-equidistant fillings patterns, namely the optimized radius dividing point in the filings zone. Then, the cooling performance variation under different non-uniform water distribution patterns was discussed based on this optimized radius dividing point. The simulation results showed that the synergetic optimization coupling the fillings and water-spraying zones improves significantly the uniformity of the air dynamic and temperature field. The water temperature drops and ventilation rate all increase firstly and then decrease with the increase of the water distribution ratio in the inner zone. Compared with the equidistant fillings layouts of 26 mm and 30 mm, after the synergetic optimization, the outlet water temperature drops increase by 0.21 ℃, 0.22 ℃, and the ventilation rate enhances by 6.68%, 1.13% respectively in the design condition, but 0.28 ℃, 0.31℃ and 7.03%, 1.53% in the typical operating condition in summer. Additionally, the evaporation loss all decreases by about 3.3% in the design condition by comparison with the equidistant fillings layouts of 26 mm and 30 mm, but increases in the typical operating condition in summer.
Deying Zhang; Zhengqing Zhang; Qiang Han; Feixiang Wu; Suoying He; Ming Gao. Numerical simulation on synergetic optimization of non-equidistant fillings and non-uniform water distribution for wet cooling towers. International Journal of Heat and Mass Transfer 2021, 179, 121676 .
AMA StyleDeying Zhang, Zhengqing Zhang, Qiang Han, Feixiang Wu, Suoying He, Ming Gao. Numerical simulation on synergetic optimization of non-equidistant fillings and non-uniform water distribution for wet cooling towers. International Journal of Heat and Mass Transfer. 2021; 179 ():121676.
Chicago/Turabian StyleDeying Zhang; Zhengqing Zhang; Qiang Han; Feixiang Wu; Suoying He; Ming Gao. 2021. "Numerical simulation on synergetic optimization of non-equidistant fillings and non-uniform water distribution for wet cooling towers." International Journal of Heat and Mass Transfer 179, no. : 121676.
Large eddy simulations and Ffowcs Williams–Hawkings acoustic analogy methods have been adopted to simulate the flow-induced noise for variable cross-section pipelines under variable flow velocity conditions in this paper, and the main influencing factors of flow-induced noise are analyzed numerically, including the flow velocity and variable diameter angle. Results manifested that the flow field distribution, sound source characteristics, and frequency spectrum characteristics of the sound pressure level (SPL) at different flow velocities follow similar trends. The average acoustic source intensity increases gradually with the increase in flow velocity. The maximum of the acoustic source intensity is located near the outlet of the variable diameter angle due to the vortex effect. The flow-induced noise in variable cross-section pipelines is mainly low-frequency noise, and its energy is mainly concentrated below 200 Hz according to the frequency spectrum characteristics. Additionally, the SPL increases with the increase in flow velocity. Compared with v = 1 m/s, the SPL at v = 2 m/s and v = 3 m/s increases by 9.4% and 22.1%, respectively. In addition, there is an approximate linearly increasing relationship between the SPL and the variable diameter angle. The minimum of the SPL appears at φ = 15.2°, and the maximum appears at φ = 25.7° at different flow velocities, which is up to 70.18 dB. Briefly, the flow-induced noise characteristics, including the average acoustic source intensity, the SPL, and the frequency spectra, are revealed in this paper. This provides a theoretical basis for the optimization of variable cross-section piping systems and the investigation of flow-induced noise control techniques.
Lihui Sun; Chuntian Zhe; Chang Guo; Shen Cheng; Suoying He; Ming Gao. Numerical simulation regarding flow-induced noise in variable cross-section pipelines based on large eddy simulations and Ffowcs Williams–Hawkings methods. AIP Advances 2021, 11, 065118 .
AMA StyleLihui Sun, Chuntian Zhe, Chang Guo, Shen Cheng, Suoying He, Ming Gao. Numerical simulation regarding flow-induced noise in variable cross-section pipelines based on large eddy simulations and Ffowcs Williams–Hawkings methods. AIP Advances. 2021; 11 (6):065118.
Chicago/Turabian StyleLihui Sun; Chuntian Zhe; Chang Guo; Shen Cheng; Suoying He; Ming Gao. 2021. "Numerical simulation regarding flow-induced noise in variable cross-section pipelines based on large eddy simulations and Ffowcs Williams–Hawkings methods." AIP Advances 11, no. 6: 065118.
Fillings are the core part of wet cooling towers, and generally speaking, the fillings are arranged in an equidistant pattern, which actually hampers the heat and mass transfer process. So the non-equidistant fillings which is the combination of large-spacing and small-spacing fillings are adopted to enhance the thermal performance. In this study, numerical simulation was conducted on one real wet cooling towers equipped for a 600 MW unit to study the relatively optimal combination of 26 mm and 30 mm spacing fillings (30 mm fillings are arranged in the inner zone and 26 mm fillings are stalled in the outer zone). The simulation results indicated that, compared with conventional equidistant fillings, the thermal and resistance performance improve partly under the non-equidistant fillings pattern. After adopting non-equidistant fillings, the aerodynamic field and the temperature field improve significantly. Furthermore, with the increase of the inner zone radius R1, the water temperature drop Δt, cooling efficiency η and Merkel number N rise first and then decline, and the relatively optimal inner radius is 47.5 m in this case. When R1 = 47.5 m, compared with 26 mm equidistant fillings condition, Δt, η, and N increase about 0.13 °C, 0.8%, and 0.03. And the ventilation rate G increases by about 751.32 kg/s at most. While the ambient air temperature changes, the non-equidistant fillings can also improve the cooling performance. Under the summer typical conditions, compared with all 26 mm and 30 mm equidistant fillings, the Δt with the relatively optimal non-equidistant fillings rises by 0.17 °C and 0.2 °C, respectively.
Rui Chen; Deying Zhang; Zhengqing Zhang; Qiang Han; Suoying He; Ming Gao. Numerical study regarding cooling capacity for non-equidistant fillings in large-scale wet cooling towers. Case Studies in Thermal Engineering 2021, 26, 101103 .
AMA StyleRui Chen, Deying Zhang, Zhengqing Zhang, Qiang Han, Suoying He, Ming Gao. Numerical study regarding cooling capacity for non-equidistant fillings in large-scale wet cooling towers. Case Studies in Thermal Engineering. 2021; 26 ():101103.
Chicago/Turabian StyleRui Chen; Deying Zhang; Zhengqing Zhang; Qiang Han; Suoying He; Ming Gao. 2021. "Numerical study regarding cooling capacity for non-equidistant fillings in large-scale wet cooling towers." Case Studies in Thermal Engineering 26, no. : 101103.
Numerical simulation is an important means to study the thermal and resistance characteristics of natural draft wet cooling towers. The treatment method of droplet diameter distribution in the rain zone directly affects the accuracy of the numerical model, which becomes a key problem in the numerical simulation at present. In this paper, to provide an appropriate treatment method of droplet diameter, three kinds of droplet diameter distribution treatment models for the numerical simulation are studied and compared, including equivalent diameter method (EDM), Gaussian distribution method (GDM), and diameter distribution method based on field test (FTDM), and the influences of each treatment method on the simulation results are presented respectively, which provide references for the subsequent numerical simulation. It is found that each method can reasonably simulate the thermal characteristics of the cooling tower by determining their key parameters, but the temperature drop calculated by FTDM is the most accurate with a relative error of 0.58%. Additionally, FTDM can most accurately simulate the pressure drop with a relative error of 4.18% and the motion trajectory of the water droplets, so the FTDM should be given priority under the premise of known the droplet diameter distribution data of the tower.
Zhengqing Zhang; Deying Zhang; Qiang Han; Feixiang Wu; Ming Gao; Suoying He. Numerical simulation on the three kinds of water droplet diameter treatments in rain zone of wet cooling towers. International Journal of Heat and Mass Transfer 2021, 170, 121054 .
AMA StyleZhengqing Zhang, Deying Zhang, Qiang Han, Feixiang Wu, Ming Gao, Suoying He. Numerical simulation on the three kinds of water droplet diameter treatments in rain zone of wet cooling towers. International Journal of Heat and Mass Transfer. 2021; 170 ():121054.
Chicago/Turabian StyleZhengqing Zhang; Deying Zhang; Qiang Han; Feixiang Wu; Ming Gao; Suoying He. 2021. "Numerical simulation on the three kinds of water droplet diameter treatments in rain zone of wet cooling towers." International Journal of Heat and Mass Transfer 170, no. : 121054.
To reveal the impact mechanism of water droplet diameter distribution in the rain zone on the cooling capacity and water-splashing noise for natural draft wet cooling towers (NDWCTs), a 3 D numerical model of thermal performance and a theoretical calculation model of water-splashing noise were established and validated, respectively. Using these two models, the influences of different diameter distributions on the ventilation, thermal performance, and the sound pressure level (SPL) of water-splashing noise were analyzed to an NDWCT used for 1000 MW unit. The diameter distribution is described by the number ratios, which is the ratio of the number of water droplets with the same diameter to the total number of all the water droplets in the rain zone. The results revealed that, as the number ratio of the water droplet with a diameter of 1 mm or 2 mm increases, the SPL decreases and the cooling capacity worsens. Conversely, when the number ratio of the water droplet with the diameter of 4 mm increases, the SPL also increases, and the cooling capacity is enhanced. In addition, an increase in the number ratio of the water droplet with a diameter of 3 mm acts to improve the ventilation and thermal performance, while the SPL demonstrates a slight reduction. Therefore, when considering the simultaneous optimization of cooling capacity and water-splashing noise, it is recommended that the number ratio of the water droplet with a diameter of 3 mm is increased. When the number ratio of the water droplet with the diameter of 3 mm reaches 45%, compared with the working condition of the actual measured water droplet diameter distribution, the outlet water temperature reduces by 0.22 °C, the ventilation rate increases by 4.72%, while there is no significant change in the SPL.
Lei Jiang; Qiang Han; Nini Wang; Ming Gao; Suoying He; Hongjun Guan; Xiaohui Tan. The effects of water droplet diameter distribution in the rain zone on the cooling capacity and water-splashing noise for natural draft wet cooling towers. International Journal of Thermal Sciences 2021, 164, 106875 .
AMA StyleLei Jiang, Qiang Han, Nini Wang, Ming Gao, Suoying He, Hongjun Guan, Xiaohui Tan. The effects of water droplet diameter distribution in the rain zone on the cooling capacity and water-splashing noise for natural draft wet cooling towers. International Journal of Thermal Sciences. 2021; 164 ():106875.
Chicago/Turabian StyleLei Jiang; Qiang Han; Nini Wang; Ming Gao; Suoying He; Hongjun Guan; Xiaohui Tan. 2021. "The effects of water droplet diameter distribution in the rain zone on the cooling capacity and water-splashing noise for natural draft wet cooling towers." International Journal of Thermal Sciences 164, no. : 106875.
A numerical simulation method based on the Ffowcs-Williams and Hawkings model is employed to predict the mechanisms of the near-field aerodynamic noise distribution characteristics of an adjustable-blade axial-flow fan with different installation angles of moving blades (Δβ). The simulated results reveal that with Δβ changing from −12° to 12°, the changing curves of the maximum total sound pressure level (MTSPL) at the tip clearance region (A region), the leading edge region (B region), and the trailing edge region (C region) exhibit an apparently rising trend, which increase by 4.0 dB, 5.7 dB, and 4.3 dB, respectively. Besides, the MTSPL at the C region is always smaller than that at A and B regions within the studied installation angles. Additionally, the acoustic energy ratio (Cpi) is the ratio of the sound energy density of a certain frequency to the total sound energy density, which shows the various frequency distribution characteristics under studied angles. It is found that when Δβ deflects from −12° to 0°, Cp1 (the acoustic energy ratio at the low-frequency in the range of 20–500) decreases from 0.71 to 0.59, Cp2 (the acoustic energy ratio at the intermediate-frequency in the range of 500–2000) increases from 0.18 to 0.25, and Cp3 (the acoustic energy ratio at the high-frequency in the range of 2000–3000) rises from 0.1 to 0.16. This study derives the aerodynamic distribution characteristics of the TSPL and acoustic energy in the near field of moving blades, which reveals its changing rules and frequency distribution under various installation angles. The conclusions may provide guidance for the research regarding the technology of the noise control of the adjustable-blade axial-flow fan.
Lin Wang; Nini Wang; Chunguo An; Suoying He; Ming Gao. Numerical simulation on near-field aerodynamic noise of an adjustable-blade axial-flow fan. AIP Advances 2020, 10, 095116 .
AMA StyleLin Wang, Nini Wang, Chunguo An, Suoying He, Ming Gao. Numerical simulation on near-field aerodynamic noise of an adjustable-blade axial-flow fan. AIP Advances. 2020; 10 (9):095116.
Chicago/Turabian StyleLin Wang; Nini Wang; Chunguo An; Suoying He; Ming Gao. 2020. "Numerical simulation on near-field aerodynamic noise of an adjustable-blade axial-flow fan." AIP Advances 10, no. 9: 095116.
To enhance the performance of the super-large natural draft wet cooling towers (S-NDWCTs), and finally to achieve the goal of energy-saving in thermal systems, the dry-wet hybrid rain zone was proposed in our previous paper. However, the previous work failed to discuss the effects of crosswind which are extremely significant for the research for S-NDWCTs. Therefore, the thermal and aerodynamic performances of the cooling tower are investigated for variation crosswind speeds (0 m/s ~ 16 m/s) and crosswind angles (0° ~ 45°) by numerical method. The results show that the airflow and circulating water temperature distributions in the dry-wet tower are more uniform than those in the usual tower within the range of studied crosswind velocities; The water temperature drop raises by about 0.40°C on average within the studied crosswind speed range; For the dry-wet rain zone tower, while the environment wind speed raises from 2 to 4 m/s, the water temperature drop decreases by 0.63°C, the ventilation rate decreases by 9.5%, the Merkel number decreases by 0.17; The influences of changing crosswind angle on the performance of wet cooling tower are not obvious.
Zhengqing Zhang; Mingyong Wang; Yang Liu; Ming Gao; Suoying He; Yuetao Shi. An exploratory research on performance improvement of super-large natural draft wet cooling tower based on the reconstructed dry-wet hybrid rain zone, part 2: Crosswind effects. International Journal of Heat and Mass Transfer 2020, 160, 120225 .
AMA StyleZhengqing Zhang, Mingyong Wang, Yang Liu, Ming Gao, Suoying He, Yuetao Shi. An exploratory research on performance improvement of super-large natural draft wet cooling tower based on the reconstructed dry-wet hybrid rain zone, part 2: Crosswind effects. International Journal of Heat and Mass Transfer. 2020; 160 ():120225.
Chicago/Turabian StyleZhengqing Zhang; Mingyong Wang; Yang Liu; Ming Gao; Suoying He; Yuetao Shi. 2020. "An exploratory research on performance improvement of super-large natural draft wet cooling tower based on the reconstructed dry-wet hybrid rain zone, part 2: Crosswind effects." International Journal of Heat and Mass Transfer 160, no. : 120225.
To explore a higher efficiency and lower noise operating condition of adjustable axial-flow fans, a three-dimensional (3D) numerical model is established to study the inside flow field distribution characteristics. Thus, it is indispensable extremely to study the flow field distribution characteristics inside axial-flow fans. In this study, the adjustable blade is installed at seven different angles \(\Delta \beta = 0^\circ , \pm 4^\circ , \pm 8^\circ , \pm 12^\circ\) to investigate the effects on the static pressure distribution in an adjustable blade axial-flow fan. The numerical results manifested that with the increase of the installation angle, the high-pressure region of the intermediate flow surface remains unchanged, but that of the top flow surface is movable. The average static pressure of the radial flow surface increases from the blade bottom to top, and the growth rate increases sharply at the highest 30% of blade. This study can provide guidance for the variable angle operation of axial-flow fans and lay a theoretical foundation for the further study of the evolution rules of aerodynamic noise under different blade angles.
Lin Wang; Kun Wang; Nini Wang; Suoying He; Yuetao Shi; Ming Gao. 3D Numerical Simulation on Flow Field Characteristic Inside the Large-Scale Adjustable Blade Axial-Flow Fan. Soil and Recycling Management in the Anthropocene Era 2020, 395 -403.
AMA StyleLin Wang, Kun Wang, Nini Wang, Suoying He, Yuetao Shi, Ming Gao. 3D Numerical Simulation on Flow Field Characteristic Inside the Large-Scale Adjustable Blade Axial-Flow Fan. Soil and Recycling Management in the Anthropocene Era. 2020; ():395-403.
Chicago/Turabian StyleLin Wang; Kun Wang; Nini Wang; Suoying He; Yuetao Shi; Ming Gao. 2020. "3D Numerical Simulation on Flow Field Characteristic Inside the Large-Scale Adjustable Blade Axial-Flow Fan." Soil and Recycling Management in the Anthropocene Era , no. : 395-403.
Flow-induced noise is a significant concern for the design and operation of centrifugal pumps. The negative impacts of flow-induced noise on operating stability, human health and the environment have been shown in many cases. This paper presents a comprehensive review of the flow-induced noise study for centrifugal pumps to synthesize the current study status. First, the generation mechanism and propagation route of flow-induced noise are discussed. Then, three kinds of study methodologies, including the theoretical study of hydrodynamic noise, numerical simulation and experimental measurement study, are summarized. Subsequently, the application of the three study methodologies to the analysis of the distribution characteristics of flow-induced noise is analyzed from aspects of the noise source identification and comparison, the frequency response analysis, the directivity characteristics of sound field and the noise changing characteristics under various operating conditions. After that, the analysis of the noise optimization design of centrifugal pumps is summarized. Finally, based on previous study results, this paper puts forward the unsolved problems and implications for future study. In conclusion, the information collected in this review paper could guide further study of the flow-induced noise of centrifugal pumps.
Chang Guo; Ming Gao; Suoying He. A Review of the Flow-Induced Noise Study for Centrifugal Pumps. Applied Sciences 2020, 10, 1022 .
AMA StyleChang Guo, Ming Gao, Suoying He. A Review of the Flow-Induced Noise Study for Centrifugal Pumps. Applied Sciences. 2020; 10 (3):1022.
Chicago/Turabian StyleChang Guo; Ming Gao; Suoying He. 2020. "A Review of the Flow-Induced Noise Study for Centrifugal Pumps." Applied Sciences 10, no. 3: 1022.
The acoustic field distribution and evolution characteristics in a time domain inside a centrifugal pump are studied. During the fluid motion process, the acoustic source and acoustic pressure are basically less than 0, and the minimum value of the two parameters is distributed near the tongue. Additionally, the concentration, break, extend, migration and reaggregation phenomena of the minimum acoustic source region exist. Specifically, as the blade passes through the tongue, the minimum acoustic source region concentrates on the tongue firstly, then extends and migrates downstream slightly with the blade motion, and aggregates again around the tongue, which results in the similar evolution characteristics of acoustic pressure. Moreover, the standard deviation (STD) of acoustic source mainly focuses near the pressure side of blade tail and volute tongue, and the maximum STD is located at the tongue. Compared with the source component induced by stretching of the vortex, the source component induced by non-uniformity of fluid kinetic energy is closer to the overall acoustic source. Take the tongue as an example, at various rotational speeds, the STD proportions of the two components are about 5% and 95%, respectively. This study discusses the generation, distribution and evolution characteristics of acoustic field, which lays a foundation to analyze the acoustic field propagation mechanism of centrifugal pumps.
Chang Guo; Jingying Wang; Ming Gao. A Numerical Study on the Distribution and Evolution Characteristics of an Acoustic Field in the Time Domain of a Centrifugal Pump Based on Powell Vortex Sound Theory. Applied Sciences 2019, 9, 5018 .
AMA StyleChang Guo, Jingying Wang, Ming Gao. A Numerical Study on the Distribution and Evolution Characteristics of an Acoustic Field in the Time Domain of a Centrifugal Pump Based on Powell Vortex Sound Theory. Applied Sciences. 2019; 9 (23):5018.
Chicago/Turabian StyleChang Guo; Jingying Wang; Ming Gao. 2019. "A Numerical Study on the Distribution and Evolution Characteristics of an Acoustic Field in the Time Domain of a Centrifugal Pump Based on Powell Vortex Sound Theory." Applied Sciences 9, no. 23: 5018.
Zhengqing Zhang; Ming Gao; Zhigang Dang; Suoying He; Fengzhong Sun. An exploratory research on performance improvement of super-large natural draft wet cooling tower based on the reconstructed dry-wet hybrid rain zone. International Journal of Heat and Mass Transfer 2019, 142, 1 .
AMA StyleZhengqing Zhang, Ming Gao, Zhigang Dang, Suoying He, Fengzhong Sun. An exploratory research on performance improvement of super-large natural draft wet cooling tower based on the reconstructed dry-wet hybrid rain zone. International Journal of Heat and Mass Transfer. 2019; 142 ():1.
Chicago/Turabian StyleZhengqing Zhang; Ming Gao; Zhigang Dang; Suoying He; Fengzhong Sun. 2019. "An exploratory research on performance improvement of super-large natural draft wet cooling tower based on the reconstructed dry-wet hybrid rain zone." International Journal of Heat and Mass Transfer 142, no. : 1.
Suoying He; Zhiyu Zhang; Ming Gao; Fengzhong Sun; Manuel Lucas; Kamel Hooman. Experimental study on the air-side flow resistance of different water collecting devices for wet cooling tower applications. Journal of Wind Engineering and Industrial Aerodynamics 2019, 190, 53 -60.
AMA StyleSuoying He, Zhiyu Zhang, Ming Gao, Fengzhong Sun, Manuel Lucas, Kamel Hooman. Experimental study on the air-side flow resistance of different water collecting devices for wet cooling tower applications. Journal of Wind Engineering and Industrial Aerodynamics. 2019; 190 ():53-60.
Chicago/Turabian StyleSuoying He; Zhiyu Zhang; Ming Gao; Fengzhong Sun; Manuel Lucas; Kamel Hooman. 2019. "Experimental study on the air-side flow resistance of different water collecting devices for wet cooling tower applications." Journal of Wind Engineering and Industrial Aerodynamics 190, no. : 53-60.
Numerical simulation method based on Powell vortex sound theory is adopted to explore the mechanisms of acoustic field distribution characteristics of a centrifugal pump with different blade outlet angles. Results reveal that with the increasing of the angle, the fluctuation range of acoustic source at the tongue in time domain extends, which causes the same fluctuation characteristics of acoustic pressure. As the angle increases from 15° to 35°, the total acoustic source intensity (TASI) and total acoustic pressure level (TAPL) at the tongue increase by 1.68% and 2.54% on average under various rotational speeds, respectively. Additionally, the TASI and TAPL show the similar directivity characteristics under different angles, and the change of the angle has slight effect on the extremum distribution characteristics. Besides, the A-weighted average acoustic pressure level (Lp) and A-weighted average acoustic source intensity level (La) are adopted to describe the overall level of TAPL and TASI. When the angle increases from 15° to 35°, the La and Lp increase gradually and increase by 1.59% and 2.21% on average under various rotational speeds, respectively. The study reveals the acoustic source and acoustic pressure distribution characteristics in time and frequency domain qualitatively and quantitatively, and manifests that the distribution and variation patterns of acoustic source lead to those of acoustic pressure. The conclusions could lay a foundation for the empirical formula proposition between acoustic pressure and acoustic source.
Chang Guo; Ming Gao; Jingying Wang; Yuetao Shi; Suoying He. The effect of blade outlet angle on the acoustic field distribution characteristics of a centrifugal pump based on Powell vortex sound theory. Applied Acoustics 2019, 155, 297 -308.
AMA StyleChang Guo, Ming Gao, Jingying Wang, Yuetao Shi, Suoying He. The effect of blade outlet angle on the acoustic field distribution characteristics of a centrifugal pump based on Powell vortex sound theory. Applied Acoustics. 2019; 155 ():297-308.
Chicago/Turabian StyleChang Guo; Ming Gao; Jingying Wang; Yuetao Shi; Suoying He. 2019. "The effect of blade outlet angle on the acoustic field distribution characteristics of a centrifugal pump based on Powell vortex sound theory." Applied Acoustics 155, no. : 297-308.
In order to evaluate the thermal performance of different zones for high level water collecting wet cooling towers (HWCTs) precisely, field test was conducted on one real HWCT equipped for a 1000 MW unit under different crosswind and water-spraying density conditions. In this paper, three parameters αs, αf and αr, which represent the cooling capacity of water-spraying zone, fillings zone and rain zone, respectively, are introduced to evaluate the crosswind influence on different zones. The variations of αs, αf and αr under windless and crosswind conditions were researched. The results demonstrate that, under windless condition, αf exceeds 88%. As crosswind velocity rises from 0.28 m/s to 4.79 m/s, when Q = 68646 t/h, αf decreases by 8.8%, while αs keeps around 10%, and αr increases by 5.6%. Additionally, it can be obtained that the cooling capacity of fillings is more outstanding under lower circulating water flow rate and small crosswind velocity conditions. Based on the test data, the fitting equations between αf and crosswind velocity are obtained. Briefly, the cooling capacity of different zones is obtained in this paper, and derived the changing rules of cooling capacity with different crosswind velocity, which can be used to guide the engineering design.
Zhigang Dang; Ming Gao; Guoqing Long; Jian Zou; Suoying He; Fengzhong Sun. Crosswind influence on cooling capacity in different zones for high level water collecting wet cooling towers based on field test. Journal of Wind Engineering and Industrial Aerodynamics 2019, 190, 134 -142.
AMA StyleZhigang Dang, Ming Gao, Guoqing Long, Jian Zou, Suoying He, Fengzhong Sun. Crosswind influence on cooling capacity in different zones for high level water collecting wet cooling towers based on field test. Journal of Wind Engineering and Industrial Aerodynamics. 2019; 190 ():134-142.
Chicago/Turabian StyleZhigang Dang; Ming Gao; Guoqing Long; Jian Zou; Suoying He; Fengzhong Sun. 2019. "Crosswind influence on cooling capacity in different zones for high level water collecting wet cooling towers based on field test." Journal of Wind Engineering and Industrial Aerodynamics 190, no. : 134-142.
In order to improve the operating performance of the natural draft wet cooling towers (NDWCTs), some structural improvement measures, including adding air-deflectors, using non-uniform fillings, and adding air-ducts, were taken in one large-scale NDWCT in China. The effects of structural improvement on the ventilation and thermal performance were researched based on the field test method. Field test results showed that, in the crosswind velocity range of 1.15–3.2 m/s (test condition), the thermal and ventilation performance decrease gradually with the rising of crosswind velocity, but the structural improvement weakens the adverse influence of crosswind. Compared with before structural improvement, the intake air uniformity coefficient, the ratio factor of ventilation rate, the temperature uniformity coefficient, and the ratio factor of Merkel number increase by about 36.6%, 15.5%, 5.5%, and, 14.5%, respectively. It manifested that the structural improvement for the NDWCT can improve the thermal and ventilation performance to a great extent.
Zhengqing Zhang; Ming Gao; Mingyong Wang; Hongjun Guan; Zhigang Dang; Suoying He; Fengzhong Sun. Field test study on thermal and ventilation performance for natural draft wet cooling tower after structural improvement. Applied Thermal Engineering 2019, 155, 305 -312.
AMA StyleZhengqing Zhang, Ming Gao, Mingyong Wang, Hongjun Guan, Zhigang Dang, Suoying He, Fengzhong Sun. Field test study on thermal and ventilation performance for natural draft wet cooling tower after structural improvement. Applied Thermal Engineering. 2019; 155 ():305-312.
Chicago/Turabian StyleZhengqing Zhang; Ming Gao; Mingyong Wang; Hongjun Guan; Zhigang Dang; Suoying He; Fengzhong Sun. 2019. "Field test study on thermal and ventilation performance for natural draft wet cooling tower after structural improvement." Applied Thermal Engineering 155, no. : 305-312.
In this paper, an axial fan was introduced for thermal performance improvement of super-large natural daft wet cooling towers (S-NDWCTs), and the model experiment was performed to study the thermal performance of S-NDWCTs installed with an axial fan under windless and crosswind conditions. The experimental results manifested that, compared with traditional natural ventilation pattern, the thermal performance of forced ventilation is outstanding by analyzing the inlet air uniformity coefficient, cooling water temperature drop, Merkel number, etc. Moreover, the cooling water temperature drop is proportional to fan power under windless condition, and it enhances approximately by 12.06% at 3.77 W fan power, compared with natural ventilation pattern. Under crosswind conditions, the inlet air uniformity coefficient (ψ) and the water temperature difference on the water basin surface at forced ventilation pattern are more uniform than those of natural ventilation pattern, and ψ at 2.67 W condition increases by 8.08% compared with natural ventilation pattern while the crosswind velocity reaches to 0.6 m/s. Additionally, the cooling water temperature drop and Merkel number at forced ventilation pattern are also higher than those of natural ventilation pattern. Compared with natural ventilation pattern, these two parameters enhance by 6.46–13.35% and 0.69–5.62%, respectively within the experimental crosswind velocity ranges (0–0.6 m/s).
Yang Zhou; Ming Gao; Guoqing Long; Zhengqing Zhang; Zhigang Dang; Suoying He; Fengzhong Sun. Experimental study regarding the effects of forced ventilation on the thermal performance for super-large natural draft wet cooling towers. Applied Thermal Engineering 2019, 155, 40 -48.
AMA StyleYang Zhou, Ming Gao, Guoqing Long, Zhengqing Zhang, Zhigang Dang, Suoying He, Fengzhong Sun. Experimental study regarding the effects of forced ventilation on the thermal performance for super-large natural draft wet cooling towers. Applied Thermal Engineering. 2019; 155 ():40-48.
Chicago/Turabian StyleYang Zhou; Ming Gao; Guoqing Long; Zhengqing Zhang; Zhigang Dang; Suoying He; Fengzhong Sun. 2019. "Experimental study regarding the effects of forced ventilation on the thermal performance for super-large natural draft wet cooling towers." Applied Thermal Engineering 155, no. : 40-48.
To predict the slurry temperature in wet flue gas desulfurization system, a theoretical model was put forward and the calculation method was set up, the correlation between the parameters of inlet flue gas and the slurry temperature was first found. Based on the predicted slurry temperature, a 1-D coupled model of droplets motion, heat and mass transfer and pressureloss of liquid-gas two phases was established, and the numerical solutions were acquired by Runge-Kutta method, meanwhile, field tests were made to validate its reliability. Additionally, the distribution characteristics of droplet velocity, temperature and relative humidity of flue gas, and pressure loss over the height of spraying zone were discussed. The effect of drop diameter and other factors on the performance of spraying process were analyzed. The results show that the slurry temperature and pressure loss agree well with the operation values with errors of less than 5% and 7%. Outlet flue gas is near saturation state under discussed range of parameters. The drop diameter is the main factor that affects the performance of wet flue gas desulfurization system.
Baokui Chen; Fengzhong Sun; Ming Gao; Yuetao Shi. A 1-D model of spraying performance for wet flue gas desulfurization scrubber based on predicted slurry temperature. Applied Thermal Engineering 2019, 155, 259 -266.
AMA StyleBaokui Chen, Fengzhong Sun, Ming Gao, Yuetao Shi. A 1-D model of spraying performance for wet flue gas desulfurization scrubber based on predicted slurry temperature. Applied Thermal Engineering. 2019; 155 ():259-266.
Chicago/Turabian StyleBaokui Chen; Fengzhong Sun; Ming Gao; Yuetao Shi. 2019. "A 1-D model of spraying performance for wet flue gas desulfurization scrubber based on predicted slurry temperature." Applied Thermal Engineering 155, no. : 259-266.
For the super large-scale natural draft wet cooling towers (S-NDWCTs), the higher rain zone produces water dropping potential energy which can be used to drive an axial fan, meanwhile, the larger diameter deteriorate the whole ventilation performance. Based on these issues, a three dimensional (3D) numerical model for a S-NDWCT equipped with an axial fan was established to analyze the thermal performance at different fan diameters and fan power. In order to evaluate the influence of fan, one dimensionless number m, represents the ratio between the fan diameter and the cooling tower diameter, was introduced in this paper, as well as air velocity uniformity coefficient ψvel and air temperature uniformity coefficient ψtem. Simulation results manifested that, compared with natural draft pattern, the thermal performance and ventilation performance of S-NDWCT with an axial fan improve partly according to these two uniformity coefficient and several thermal performance parameters, and they improve continuously with the increasing of fan diameter and fan power. At the given fan rotate speed (20 rpm), the water temperature drop ΔT, ventilation rate G, Merkel number N and cooling efficiency η enhance persistently as the diameter of the fan increases, while these parameters enhance firstly, and then reduce at the given power (300 kW). Under 15.0 m fan diameter (m = 0.125) and 300 kW fan power conditions, compared with natural draft pattern, ΔT, G, N, and η all reach to the maximum of 9.31 °C, 31,549 kg/s, 1.65 and 53.5%, and enhance by 0.14 °C, 611 kg/s, 0.04 and 0.8%, respectively. It demonstrates that the cooling tower shows out the outstanding thermal and ventilation performance when the diameter ratio m is 0.125.
Zhigang Dang; Zhengqing Zhang; Ming Gao; Suoying He. Numerical simulation of thermal performance for super large-scale wet cooling tower equipped with an axial fan. International Journal of Heat and Mass Transfer 2019, 135, 220 -234.
AMA StyleZhigang Dang, Zhengqing Zhang, Ming Gao, Suoying He. Numerical simulation of thermal performance for super large-scale wet cooling tower equipped with an axial fan. International Journal of Heat and Mass Transfer. 2019; 135 ():220-234.
Chicago/Turabian StyleZhigang Dang; Zhengqing Zhang; Ming Gao; Suoying He. 2019. "Numerical simulation of thermal performance for super large-scale wet cooling tower equipped with an axial fan." International Journal of Heat and Mass Transfer 135, no. : 220-234.