The Effect of Chamber Pressure on the Thermal Performance of New Refrigerant R513a During Spray Cooling

2019 ◽  
Author(s):  
Nabeel M. Abdulrazzaq ◽  
Azzam S. Salman ◽  
Noble Anumbe ◽  
Amitav Tikadar ◽  
Saad K. Oudah ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Closed Loop ◽  
Cooling System ◽  
Heated Surface ◽  
Saturation Temperature ◽  
Spray Cooling ◽  
Copper Surface ◽  
Chamber Pressure ◽  
Refrigeration System ◽  
Spray Chamber

Abstract In this paper, the performance of a new low-GWP refrigerant R513a was experimentally investigated, during spray cooling. A spray cooling system was designed to work as a sub-system within a closed-loop refrigeration system. The influence of chamber pressure on heat flux and heat transfer coefficient were experimentally investigated. A smooth plain copper surface heated by a cartridge heater was cooled by the refrigerant (R513a) while flowing through a nozzle in the spray chamber. The results showed that chamber pressure has a significant impact on the overall thermal performance of the spray cooling operation. It was also determined that higher chamber pressures resulted in higher thermal performance. The highest chamber pressure attained in this study was 0.6 MPa. Furthermore, the surface temperature of the heated surface increased due to the increase of the saturation temperature of the liquid over the surface.

Spray Cooling for Time Resolved Emission Measurements of ICs

2004 ◽  
Author(s):  
Rama R. Goruganthu ◽  
David Bethke ◽  
Shawn McBride ◽  
Tom Crawford ◽  
Jonathan Frank ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Performance ◽  
Flip Chip ◽  
Cooling System ◽  
Spray Cooling ◽  
Junction Temperature ◽  
Maximum Temperature ◽  
Uniform Heat Flux ◽  
High Heat Flux ◽  
Time Resolved

Abstract Spray cooling is implemented on an engineering tool for Time Resolved Emission measurements using a silicon solid immersion lens to achieve high spatial resolution and for probing high heat flux devices. Thermal performance is characterized using a thermal test vehicle consisting of a 4x3 array of cells each with a heater element and a thermal diode to monitor the temperature within the cell. The flip-chip packaged TTV is operated to achieve uniform heat flux across the die. The temperature distribution across the die is measured on the 4x3 grid of the die for various heat loads up to 180 W with corresponding heat flux of 204 W/cm2. Using water as coolant the maximum temperature differential across the die was about 30 °C while keeping the maximum junction temperature below 95 °C and at a heat flux of 200 W/cm2. Details of the thermal performance of spray cooling system as a function of flow rate, coolant

A gas-atomized spray cooling system integrated with an ejector loop: Ejector modeling and thermal performance analysis

2019 ◽  
Vol 180 ◽  
pp. 106-118 ◽  
Author(s):  
Ji-Xiang Wang ◽  
Yun-Ze Li ◽  
Jia-Xin Li ◽  
Chao Li ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Thermal Performance ◽  
Cooling System ◽  
Spray Cooling

scholarly journals Ground experimental investigations into an ejected spray cooling system for space closed-loop application

2016 ◽  
Vol 29 (3) ◽  
pp. 630-638 ◽  
Author(s):  
Hongsheng Zhang ◽  
Yunze Li ◽  
Shengnan Wang ◽  
Yang Liu ◽  
Mingliang Zhong
Keyword(s):  
Closed Loop ◽  
Cooling System ◽  
Spray Cooling ◽  
Experimental Investigations

Startup time of closed loop spray cooling system

2011 ◽  
Vol 23 (9) ◽  
pp. 2356-2360
Author(s):  
王照亮 Wang Zhaoliang ◽  
马永 Ma Yong ◽  
张伟 Zhang Wei ◽  
赵欣 Zhao Xin
Keyword(s):  
Closed Loop ◽  
Cooling System ◽  
Spray Cooling ◽  
Startup Time

Multi-Nozzle Spray Cooling in a Closed Loop

2011 ◽  
Author(s):  
Lanchao Lin ◽  
Quinn Leland
Keyword(s):  
Thermal Performance ◽  
Closed Loop ◽  
Target Surface ◽  
Spray Cooling ◽  
High Heat ◽  
High Heat Flux ◽  
Gear Pump ◽  
Two Phase ◽  
Power Sources ◽  
Phase Loop

A closed two-phase loop system was developed that combined with a multi-nozzle spray cooling unit for the cooling of high heat flux power sources. The fluid circulation was sustained by a magnetic gear pump operating with an ejector pump unit. The motive flow of the ejector shared the pumping liquid flow with the multi-nozzle spray. The use of the ejector stabilized the circulation of the two-phase flow. A multi-nozzle plate with 48 miniature nozzles was designed to generate an array of 4×12 sprays. A closed loop spray cooling experimental setup with a cooling area of 19.3 cm2 was built. The spray nozzle to target distance was 10 mm. Water and FC-72 were used as the working fluids. Spray cooling experiments were performed in three orientations of the spray target surface, namely (a) horizontal facing upward, (b) vertical, and (c) horizontal facing downward. The thermal performance of the horizontal facing downward surface was the best. A comparison with the thermal performance data for a smaller cooling surface area of 2.0 cm2 was made.

Experimental Study of Inclination on Non-Boiling Regime Spray Cooling

2008 ◽  
Author(s):  
Yongxian Guo ◽  
Jianyuan Jia ◽  
Weidong Wang ◽  
Shaorong Zhou
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heated Surface ◽  
Spray Cooling ◽  
Copper Surface ◽  
Experimental Results ◽  
Working Fluid ◽  
Distilled Water ◽  
Optimal Heat ◽  
Inclination Angles

Based on the maximum CHF (critical heat flux) criterion, an optimal heat transfer criterion, which is called H criterion, was proposed. Experimental apparatuses were conducted. Distilled water was used as the working fluid. Three different DANFOSS nozzles with cone angles being 54°, 50° and 54° respectively were used. A 30×30mm2 square copper surface was used as the heated surface. Experimental results indicated that the volumetric fluxes were proportioned to P0.5, where P is the pressure drop across the nozzles. The optimal distance between the nozzles and the heated surface were derived. The results indicated that the optimal heat transfer appeared while the outside of the impellent thin spray film inscribed in the square heated surface. Based on the H criterion aforementioned, two DANFOSS nozzles of the three, with cone angles being 54° and 50° respectively, were used to study the temperature distribution of the heated surface while there were spray inclination angles during spray cooling experiments. Distilled water was also used impacting on the 30×30mm2 square copper surface aforementioned and a circular heated copper surface with diameters being 30mm respectively. The heat flux of the surface was kept in constant (about 26–35W/cm2). The inclination angles were 0°, 10°, 20°, 30°, 40° and 50° respectively. Three thermocouples imbedded in the heated surface were used to predict the grads of the temperature of the surface. Experimental results indicated that the temperature and the grads of the temperature of the surface increases first and then decreases with the increase of the inclination angle.

Influence of air on heat transfer of a closed-loop spray cooling system

2020 ◽  
Vol 111 ◽  
pp. 109903 ◽  
Author(s):  
Pengfei Liu ◽  
Ranjith Kandasamy ◽  
Huicheng Feng ◽  
Teck Neng Wong ◽  
Kok Chuan Toh
Keyword(s):  
Heat Transfer ◽  
Closed Loop ◽  
Cooling System ◽  
Spray Cooling

Formation of Nano-Adsorption Layer and Its Effects on Nanofluid Spray Heat Transfer Performance

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Tong-Bou Chang
Keyword(s):  
Heat Transfer ◽  
Layer Thickness ◽  
Adsorption Layer ◽  
Heat Transfer Performance ◽  
Cooling System ◽  
Heated Surface ◽  
Spray Cooling ◽  
Working Fluid ◽  
Transfer Performance ◽  
Test Pieces

For spray cooling using nanofluid as the working fluid, a nano-adsorption layer is formed on the heated surface and affects the heat transfer performance of the cooling system. This study performs an experimental investigation into the formation of this nano-adsorption layer and its subsequent effects on the spray heat transfer performance of a cooling system using Al2O3–water nanofluid as the working fluid. The experiments consider four different nanoparticle volume fractions (i.e., 0 vol. %, 0.001 vol. %, 0.025 vol. %, and 0.05 vol. %) and two different surface roughnesses (i.e., 0.1 μm and 1.0 μm). The experimental results show that the 0.001 vol. % nanofluid yields the optimal heat transfer performance since most of the nanoparticles rebound from the heated surface directly on impact or are washed away by subsequently arriving droplets. The surface compositions of the spray-cooled specimens are examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results reveal that for all of the nanofluids, a nano-adsorption layer is formed on the surface of the spray-cooled test pieces. Moreover, the layer thickness increases with an increasing nanoparticle concentration. A greater nano-adsorption layer thickness not only results in a higher thermal resistance but also reduces the effect of the surface roughness in enhancing the heat transfer performance. In addition, the nano-adsorption layer absorbs the nanofluid droplets under the effects of capillary forces, and therefore reduces the contact angle, which induces a hydrophilic surface property.

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