Development of Closed loop pulsating heat pipes for application at elevated evaporator temperaturePulsating heat pipe (PHP) is a closed two-phase heat transfer device in which heat is transported from the evaporator section to the condenser section due to oscillating motion of the working fluid. Proper designing and better thermal performance of a PHP require considerations of the physical phenomena occurring inside it. These phenomena are primarily controlled by thermo-physical properties of the working fluid, the geometrical parameters of the PHP and the operational parameters or constraints to the system. Though simple in construction, the complicated thermo-fluidic physics of the PHPs and the high heat transfer rate has motivated the candidate to implement it for high temperature applications keeping the emphasis focused on nuclear power plants. In this study, the main aim is to increase the operational temperature range of the PHP. In this regard, suitable heat transfer fluids (KoolGard, Olive oil, Therminol-66 and Dowtherm-A) are considered to investigate the thermo-fluidic behaviour of the device. Initially, experiments are performed to study the behaviour of the fluid inside the PHP made of quartz tube. Complementary experiments are performed in copper tube made metallic loop for temperature measurements in PHP. Thereafter, the selected fluids are analysed over the important dimensionless numbers affecting the thermal performance of the PHP. Phenomenal difference in start-up, operational behaviour and flow regimes is observed for different fluids, which could be attributed to the difference in thermo-physical properties of fluids and their capability for transferring heat. Comparing rigorous experimental results for different fluids, Dowtherm A is selected as a possible option for high temperature applications and investigated for the later part of the work. Next, detailed experiments are planned to study the flow behavior and heat transfer characteristic of water (as benchmark fluid) and Dowtherm-A in a three-turn CLPHP. Variation of important operational parameters, mainly heat input, filling ratio and inclination angle are considered and their effect on the thermal performance of the device is investigated. Effect of inclination is studied for two mutually perpendicular axes of rotation. Investigation reveals the characteristic behavior of the fluid and establishes operational domain in terms of the controlling parameters. Successful start-up and operation at high temperature is achieved using Dowtherm-A. It has been also observed through experiment that the number of turns (N) is one of the primary parameters affecting the performance of the PHP. A low value of N puts limit over the performance of the PHP at different orientations. However, higher value of N relaxes this limit imposed by the gravitational force and scales up the heat transport capacity of the device, yet very large N leads to a detrimental effect in transfer of heat flux. Thus, a critical N exists which is observed to be strongly dependent on the working fluid. Therefore, after establishing successful operation of the PHP with working fluid Dowtherm-A in three-turn PHP, experiments are conducted in 14 and 30-turn PHPs for high temperature industrial applications. Parametric variation similar to that performed for three-turn PHP is considered. Using experimental results for various heat input and filling ratio, in a similar path as for three-turn PHP, operational limits and optimum value for performance have been proposed. For inclination angle, improvement in performance is observed with the increase in N. Further, with the 30-turn PHP, performance, independent of inclination, is achieved at high heat input.
38 Comments
5/9/2022 22:05:06
Really informative article, I had the opportunity to learn a lot, thank you. https://freecodezilla.net/wondershare-filmora-9-free-download/
Reply
12/9/2022 13:28:20
Really informative article, I had the opportunity to learn a lot, thank you. https://odemebozdurma.com/
Reply
15/9/2022 06:29:43
Really informative article, I had the opportunity to learn a lot, thank you. https://bit.ly/site-kurma
Reply
30/9/2022 17:41:17
It's great to have this type of content. Good luck with your spirit. Thank you. https://bit.ly/site-kurma
Reply
6/10/2022 02:05:03
It was a post that I found very successful. Good luck to you. https://escortnova.com/escort-ilanlari/bitlis-escort/
Reply
6/10/2022 22:15:41
I support your continuation of your posts. I will be happy as new posts come. Thank you. https://escortnova.com/escort-ilanlari/tokat-escort/yesilyurt-escort-tokat-escort/
Reply
7/10/2022 15:19:29
I think the content is at a successful level. It adds enough information. Thank you. https://escortnova.com/escort-ilanlari/tokat-escort/
Reply
8/10/2022 11:56:48
Thank you for your sharing. I must say that I am successful in your content. https://escortnova.com/escort-ilanlari/sanliurfa-escort/virasehir-escort/
Reply
22/11/2022 02:03:06
Hemen Göz At evde para kazanmaya basla: https://sites.google.com/view/evden-ek-is/
Reply
10/12/2022 01:27:53
Uygun fiyatlardan takipçi satın al: https://takipcialdim.com/
Reply
10/12/2022 04:42:47
Tiktok takipçi satın almak için tıkla: https://takipcialdim.com/tiktok-takipci-satin-al/
Reply
10/12/2022 04:48:34
İnstagram beğeni takipçi satın al: https://takipcialdim.com/instagram-begeni-satin-al/
Reply
16/12/2022 00:44:52
uygun fiyatlardan takipçi Hemen Göz At: https://takipcim.com.tr/
Reply
21/12/2022 16:34:36
İnstagram takipçi satın almak istiyorsan tıkla.
Reply
5/1/2023 01:32:07
100 tl deneme bonusu veren siteleri öğrenmek istiyorsan tıkla.
Reply
8/1/2023 21:20:47
100 tl deneme bonusu veren siteleri öğrenmek istiyorsan tıkla.
Reply
11/5/2023 04:51:16
Heets Çeşitlerine Göz At: https://bit.ly/heets-heets
Reply
30/6/2023 20:25:06
En iyi gümüşhane ilan sitesi burada. https://gumushane.escorthun.com/
Reply
10/8/2023 00:25:50
Steroid Siparis Steroid Fiyatlari Steroidler Anabolizan Orjinal Steroid Steroid Satis Steroid Satın Al Steroid Siparis Et
Reply
16/8/2023 01:47:22
https://www.sporunuyap8.com/ teşekkürler
Reply
Leave a Reply. |
Dr. Arup Kumar DasHere you will get the latest updates of the research work. Archives
February 2024
Categories |