scholarly journals Experimental Analysis on Heat Release of Pulsating Heat Pipe Phase Change Regenerator with Different Working Fluids

2021 ◽  
Vol 2087 (1) ◽  
pp. 012008
Author(s):  
Xiaohui Lu ◽  
Xiaoxue Luo ◽  
Shibo Cao ◽  
Changzhen Zou ◽  
Xiaochun Han
Keyword(s):  
Phase Change ◽  
Heat Release ◽  
Heat Pipe ◽  
Initial Temperature ◽  
Heat Storage ◽  
Cooling Water ◽  
Release Time ◽  
Pulsating Heat Pipe ◽  
Release Process ◽  
Release Device

Abstract In order to improve the problems of serious energy waste and low utilization rate, this paper designs and builds an experimental platform for a pulsating heat pipe type phase change heat storage device. The temperature changes with time in the heat storage and release device of the barium hydroxide octahydrate phase change material under different working conditions is studied. The results show that during the heat release process, when the pulsating heat pipe is filled with water, the cooling water temperature rises to the highest, and the heat recovery rate is as high as 64%. Otherwise, the initial temperature of the cooling water during the heat release process is studied. Result shows that the initial temperature of the cooling water increases, the longer the latent heat of phase change and the total heat release time, and the higher the temperature rise of the cooling water. The experimental design of this paper can provide a reference for researchers in related fields.

The Start-Up Performance of Pulsating Heat Pipe With Communicating Pipe at Different Inclination Angles

2019 ◽  
Author(s):  
Fu-Min Shang ◽  
Shi-Long Fan ◽  
Jian-Hong Liu
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Heat Pipe ◽  
Heat Transfer Performance ◽  
Working Fluid ◽  
Transfer Performance ◽  
Pulsating Heat Pipe ◽  
High Heat Transfer ◽  
Start Up ◽  
Inclination Angles

Abstract The pulsating heat pipe (PHP) is a passive cooling device, which has the advantages of simple structure, high heat transfer performance and low production cost. The complex vapor-liquid phase change occurs in the in the initial stage of PHP. In this work, we explore the start-up performance of PHP at different inclination angles and the experiment shows that start-up performance is respectively different when the angles are 0°, 45°, 90°, 135° and 180°. Since the gravitational auxiliary function, the working fluid in the communicating pipe which takes longer time to vaporize change phase earlier than that in PHP’s loop when the angles are 0° and 45°. Nevertheless, when the angle is 90°, the phase change of working fluid in communicating pipe and in the loop occurs at the same time. Meanwhile, the oscillating mode affects the stability of the starting and heat transfer performance of the PHP.

scholarly journals The Concept, Technical System and Heat Transfer Analysis on Phase-Change Heat Storage Backfill for Exploitation of Geothermal Energy

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4755
Author(s):  
Xiaoyan Zhang ◽  
Muyan Xu ◽  
Li Liu ◽  
Lang Liu ◽  
Mei Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Phase Change ◽  
Heat Release ◽  
Geothermal Energy ◽  
Heat Storage ◽  
Collaborative Optimization ◽  
Technical System ◽  
Heat Transfer Analysis ◽  
Mutual Cooperation

In view of high ground stress, high geothermal temperature, and thermal hazard during deep mineral resource exploitation, the concept of phase-change heat storage backfill was put forward in this study. Further, the corresponding technical system was constructed and the main content involved in technical system, which is the optimized proportion of the backfill slurry added with phase-change materials (PCMs), was examined. Moreover, we elaborated upon the collaborative optimization of a backfill body’s mechanical and thermal properties and the mutual cooperation on backfill mining, geothermal energy exploitation, and simultaneous stope cooling. The heat transfer behavior of a backfill body plays a key role in technology system. We numerically simulated the heat transfer among a backfill body, surrounding rock, and airflow in the heat storage process, as well as the heat transfer between backfill body and cold fluid during the heat release process. The temperature distribution of a backfill body at different heat storage/heat release times—i.e., the temperature distribution and its evolution—with heat transfer were revealed and analyzed. This study can provide theoretical guidance for a phase-change heat storage backfill, as it has an important significance for the collaborative exploitation of mineral resources and geothermal energy.

Heat Transfer Characteristics of a 3-D Printed Pulsating Heat Pipe: Fundamental Experiments Using Water As a Working Fluid

2017 ◽  
Author(s):  
Yasushi Koito ◽  
Masahiro Kawaji
Keyword(s):  
Heat Pipe ◽  
Cooling Water ◽  
Experimental Results ◽  
Working Fluid ◽  
Transient Temperature ◽  
Pulsating Heat Pipe ◽  
Two Phase ◽  
Condenser Section ◽  
Heater Power ◽  
Cooling Water Temperature

This paper describes extended experiments on a pulsating heat pipe (PHP) fabricated by using a 3-D printer and a graphene-laden PLA (PolyLactic Acid) filament. Water was used as a working fluid. To maintain airtightness, the 3-D printed PHP was electroplated by copper since the graphene in the filament allows electric currents to pass through. The PHP had ten square channels. A cross section and a length of the square channel were 1.5 mm × 1.5 mm and 80 mm, respectively. Ends of each channel were connected to form a single serpentine channel. A filling ratio of the working fluid was 50%. In experiments, an evaporator section of the PHP was heated by a heater and a condenser section was cooled using a water-cooling jacket. The heater power was increased stepwise from 2.0 W to 7.0 W while the cooling water temperature and its flow rate were maintained at 4.0 °C and 0.25 LPM, respectively. Transient temperature distributions of the PHP were measured by K-type thermocouples. From the experimental results, steady-state two-phase heat transport operation of the PHP was confirmed for the heater power between 3.0 W and 6.0 W. Moreover, the present experimental results were compared with the previous ones, where ethanol was used as the working fluid. It was also confirmed that the thermal resistance of the PHP with ethanol was slightly smaller than that with water.

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