Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production Theory
A regulating valve is a key control element in the coal liquefaction industry, whose flow field distribution is related to the entropy production. In order to make a quantitative evaluation of the energy loss in the cavitation flow and calculate the magnitude and location of the hydraulic loss in th...
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| Format: | Article |
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MDPI AG
2022-09-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/15/17/6480 |
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| author | Jie He Qihang Liu Zheng Long Yujia Zhang Xiumei Liu Shaobing Xiang Beibei Li Shuyun Qiao |
| author_facet | Jie He Qihang Liu Zheng Long Yujia Zhang Xiumei Liu Shaobing Xiang Beibei Li Shuyun Qiao |
| author_sort | Jie He |
| collection | DOAJ |
| description | A regulating valve is a key control element in the coal liquefaction industry, whose flow field distribution is related to the entropy production. In order to make a quantitative evaluation of the energy loss in the cavitation flow and calculate the magnitude and location of the hydraulic loss in the flow field more accurately, entropy production theory is employed to analyze the flow field in the regulating valve numerically. The entropy production under cavitation condition and its influence on steady-state flow force are also discussed. When the opening of the valve increases, the entropy production and energy loss change dramatically. The entropy production rate (EPR) is mainly distributed at the orifice and downstream of the regulating valve, the entropy production rate (EPR) reaches the maximum value at the orifice, and turbulent pulsation entropy production (TPEP) is the main part of the total entropy production for flow. When the valve’s opening increases from 40% to 70%, the total entropy production (TEP) increases from 467.14 W/K to 630.04 W/K. The entropy production by cavitation (EPC) increases firstly and then decreases. The smallest value of EPC is 0.103 W/K at the 40% opening, while the maximum value is 0.119 W/K at 60% opening. Furthermore, the relationship between total entropy production (TEP) and steady-state flow force can be approximated by an exponential distribution. When the steady-state flow force increases, the total entropy production for flow also increases. Cavitation effect on the steady-state flow force is strengthened firstly and then weakened with increasing the valve’s opening. Finally, a discriminant method based on the change of the steady-state flow force is proposed to detect whether cavitation occurs in the valve or not. The results in this paper could provided a directional and quantitative evaluation of energy loss in the regulating valve, which is help for the structural shape optimization and service life extension combining with external characteristics of the valve and internal flow field. |
| first_indexed | 2024-03-10T01:50:16Z |
| format | Article |
| id | doaj.art-a9815f88cb6046319c179f251fc4c8ad |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T01:50:16Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-a9815f88cb6046319c179f251fc4c8ad2023-11-23T13:06:56ZengMDPI AGEnergies1996-10732022-09-011517648010.3390/en15176480Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production TheoryJie He0Qihang Liu1Zheng Long2Yujia Zhang3Xiumei Liu4Shaobing Xiang5Beibei Li6Shuyun Qiao7School of Electrical and Control Engineering, Xuzhou University of Technology, Xuzhou 221018, ChinaMechatronic Engineering Institution, China University of Mining and Technology, Xuzhou 221116, ChinaChina Tobacco Shangdong Industrial Co., Ltd., Jinan 250014, ChinaMechatronic Engineering Institution, China University of Mining and Technology, Xuzhou 221116, ChinaMechatronic Engineering Institution, China University of Mining and Technology, Xuzhou 221116, ChinaMechatronic Engineering Institution, China University of Mining and Technology, Xuzhou 221116, ChinaMechatronic Engineering Institution, China University of Mining and Technology, Xuzhou 221116, ChinaSchool of Electrical and Control Engineering, Xuzhou University of Technology, Xuzhou 221018, ChinaA regulating valve is a key control element in the coal liquefaction industry, whose flow field distribution is related to the entropy production. In order to make a quantitative evaluation of the energy loss in the cavitation flow and calculate the magnitude and location of the hydraulic loss in the flow field more accurately, entropy production theory is employed to analyze the flow field in the regulating valve numerically. The entropy production under cavitation condition and its influence on steady-state flow force are also discussed. When the opening of the valve increases, the entropy production and energy loss change dramatically. The entropy production rate (EPR) is mainly distributed at the orifice and downstream of the regulating valve, the entropy production rate (EPR) reaches the maximum value at the orifice, and turbulent pulsation entropy production (TPEP) is the main part of the total entropy production for flow. When the valve’s opening increases from 40% to 70%, the total entropy production (TEP) increases from 467.14 W/K to 630.04 W/K. The entropy production by cavitation (EPC) increases firstly and then decreases. The smallest value of EPC is 0.103 W/K at the 40% opening, while the maximum value is 0.119 W/K at 60% opening. Furthermore, the relationship between total entropy production (TEP) and steady-state flow force can be approximated by an exponential distribution. When the steady-state flow force increases, the total entropy production for flow also increases. Cavitation effect on the steady-state flow force is strengthened firstly and then weakened with increasing the valve’s opening. Finally, a discriminant method based on the change of the steady-state flow force is proposed to detect whether cavitation occurs in the valve or not. The results in this paper could provided a directional and quantitative evaluation of energy loss in the regulating valve, which is help for the structural shape optimization and service life extension combining with external characteristics of the valve and internal flow field.https://www.mdpi.com/1996-1073/15/17/6480regulating valveentropy productionflow forcecavitation |
| spellingShingle | Jie He Qihang Liu Zheng Long Yujia Zhang Xiumei Liu Shaobing Xiang Beibei Li Shuyun Qiao Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production Theory Energies regulating valve entropy production flow force cavitation |
| title | Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production Theory |
| title_full | Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production Theory |
| title_fullStr | Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production Theory |
| title_full_unstemmed | Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production Theory |
| title_short | Characteristics of Cavitation Flow for a Regulating Valve Based on Entropy Production Theory |
| title_sort | characteristics of cavitation flow for a regulating valve based on entropy production theory |
| topic | regulating valve entropy production flow force cavitation |
| url | https://www.mdpi.com/1996-1073/15/17/6480 |
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