The Experts below are selected from a list of 27 Experts worldwide ranked by ideXlab platform

Youngseok Choi - One of the best experts on this subject based on the ideXlab platform.

  • positive displacement turbine a novel solution to the pressure Differential Control Valve failure problem and energy utilization
    Energy, 2020
    Co-Authors: Arihant Sonawat, Hyeonmo Yang, Youngseok Choi
    Abstract:

    Abstract Micro hydro turbines are getting renewed research interest in recovering unused energy from systems like water supply pipelines, sewage treatment and transportation plants, chemical and oil refineries, etc. and making them energy efficient for sustainable development. The present work dealt with this aspect wherein the unused energy of the hot water transportation pipelines, which was earlier throttled by pressure Differential Control Valve (PDCV), was harvested and used elsewhere. A special class of multi-purpose micro hydro turbine known as the positive displacement turbine was developed for the present application which involved very low flow rates with high heads and very low specific speeds and to replace the PDCV which was frequently failing due to cavitation causing loss of energy. A framework was developed for designing such turbines and predicting their performance using CFD. The reasons for the occurrence of cavitation and flow pulsations were also examined and remedial measures were incorporated for their elimination. At the rated condition during experimental study, the base design generated 7.31 kW power with an overall efficiency of 67.7%. The socio-economic analysis was also carried out which concluded that the PDT will aid in energy conservation and reduction in CO2 emissions.

  • Effect of Stator Geometry on the Performance of a Positive Displacement Hydraulic Turbine
    Volume 3B: Fluid Applications and Systems, 2019
    Co-Authors: Arihant Sonawat, Youngseok Choi, Hyeonmo Yang
    Abstract:

    Abstract Positive displacement turbine (PDT) is a special class of hydraulic turbine which finds its usage in the applications involving very low flow rates with high heads and very low specific speeds. In the present case, a PDT was designed and developed to replace the pressure Differential Control Valve (PDCV) and to harness the unused Differential pressure energy from the water supply pipeline system. The turbine was designed considering the on-site available head and flowrate. The rotors were twisted to damp the fluctuations in pressure, flow rate and torque. The primary objective of the present study was to analyze the effect of the stator shape on the performance of PDT using Computational Fluid Dynamics approach. The governing equations of the fluid flow were solved using an unsteady approach to capture accurately the pulsating nature of the flow using ANSYS CFX v17.1. Initially a circular stator turbine was used for transporting the working fluid to and from the turbine rotors and later the effects of square and rectangular shaped stator designs were also checked. It was observed that the performance of the PDT slightly improved with rectangular and square stators in terms of hydraulic efficiency than with circular stator with low flow fluctuations.

Arihant Sonawat - One of the best experts on this subject based on the ideXlab platform.

  • positive displacement turbine a novel solution to the pressure Differential Control Valve failure problem and energy utilization
    Energy, 2020
    Co-Authors: Arihant Sonawat, Hyeonmo Yang, Youngseok Choi
    Abstract:

    Abstract Micro hydro turbines are getting renewed research interest in recovering unused energy from systems like water supply pipelines, sewage treatment and transportation plants, chemical and oil refineries, etc. and making them energy efficient for sustainable development. The present work dealt with this aspect wherein the unused energy of the hot water transportation pipelines, which was earlier throttled by pressure Differential Control Valve (PDCV), was harvested and used elsewhere. A special class of multi-purpose micro hydro turbine known as the positive displacement turbine was developed for the present application which involved very low flow rates with high heads and very low specific speeds and to replace the PDCV which was frequently failing due to cavitation causing loss of energy. A framework was developed for designing such turbines and predicting their performance using CFD. The reasons for the occurrence of cavitation and flow pulsations were also examined and remedial measures were incorporated for their elimination. At the rated condition during experimental study, the base design generated 7.31 kW power with an overall efficiency of 67.7%. The socio-economic analysis was also carried out which concluded that the PDT will aid in energy conservation and reduction in CO2 emissions.

  • Effect of Stator Geometry on the Performance of a Positive Displacement Hydraulic Turbine
    Volume 3B: Fluid Applications and Systems, 2019
    Co-Authors: Arihant Sonawat, Youngseok Choi, Hyeonmo Yang
    Abstract:

    Abstract Positive displacement turbine (PDT) is a special class of hydraulic turbine which finds its usage in the applications involving very low flow rates with high heads and very low specific speeds. In the present case, a PDT was designed and developed to replace the pressure Differential Control Valve (PDCV) and to harness the unused Differential pressure energy from the water supply pipeline system. The turbine was designed considering the on-site available head and flowrate. The rotors were twisted to damp the fluctuations in pressure, flow rate and torque. The primary objective of the present study was to analyze the effect of the stator shape on the performance of PDT using Computational Fluid Dynamics approach. The governing equations of the fluid flow were solved using an unsteady approach to capture accurately the pulsating nature of the flow using ANSYS CFX v17.1. Initially a circular stator turbine was used for transporting the working fluid to and from the turbine rotors and later the effects of square and rectangular shaped stator designs were also checked. It was observed that the performance of the PDT slightly improved with rectangular and square stators in terms of hydraulic efficiency than with circular stator with low flow fluctuations.

Hyeonmo Yang - One of the best experts on this subject based on the ideXlab platform.

  • positive displacement turbine a novel solution to the pressure Differential Control Valve failure problem and energy utilization
    Energy, 2020
    Co-Authors: Arihant Sonawat, Hyeonmo Yang, Youngseok Choi
    Abstract:

    Abstract Micro hydro turbines are getting renewed research interest in recovering unused energy from systems like water supply pipelines, sewage treatment and transportation plants, chemical and oil refineries, etc. and making them energy efficient for sustainable development. The present work dealt with this aspect wherein the unused energy of the hot water transportation pipelines, which was earlier throttled by pressure Differential Control Valve (PDCV), was harvested and used elsewhere. A special class of multi-purpose micro hydro turbine known as the positive displacement turbine was developed for the present application which involved very low flow rates with high heads and very low specific speeds and to replace the PDCV which was frequently failing due to cavitation causing loss of energy. A framework was developed for designing such turbines and predicting their performance using CFD. The reasons for the occurrence of cavitation and flow pulsations were also examined and remedial measures were incorporated for their elimination. At the rated condition during experimental study, the base design generated 7.31 kW power with an overall efficiency of 67.7%. The socio-economic analysis was also carried out which concluded that the PDT will aid in energy conservation and reduction in CO2 emissions.

  • Effect of Stator Geometry on the Performance of a Positive Displacement Hydraulic Turbine
    Volume 3B: Fluid Applications and Systems, 2019
    Co-Authors: Arihant Sonawat, Youngseok Choi, Hyeonmo Yang
    Abstract:

    Abstract Positive displacement turbine (PDT) is a special class of hydraulic turbine which finds its usage in the applications involving very low flow rates with high heads and very low specific speeds. In the present case, a PDT was designed and developed to replace the pressure Differential Control Valve (PDCV) and to harness the unused Differential pressure energy from the water supply pipeline system. The turbine was designed considering the on-site available head and flowrate. The rotors were twisted to damp the fluctuations in pressure, flow rate and torque. The primary objective of the present study was to analyze the effect of the stator shape on the performance of PDT using Computational Fluid Dynamics approach. The governing equations of the fluid flow were solved using an unsteady approach to capture accurately the pulsating nature of the flow using ANSYS CFX v17.1. Initially a circular stator turbine was used for transporting the working fluid to and from the turbine rotors and later the effects of square and rectangular shaped stator designs were also checked. It was observed that the performance of the PDT slightly improved with rectangular and square stators in terms of hydraulic efficiency than with circular stator with low flow fluctuations.

Sung Yong Park - One of the best experts on this subject based on the ideXlab platform.

  • Power Generation System for Using Unused Energy in District Heating Pipelines
    Energy Procedia, 2018
    Co-Authors: Mun Sei Oh, Sung Yong Park
    Abstract:

    Abstract When the hot water for district heating (DH) is supplied through a thermal grid, a pressure Differential Control Valve (PDCV) in a substation protects the users’ equipment from the high pressure water and helps to supply DH water to long distance. It also Controls the constant temperature and adjusts the constant pressure in the thermal grid. However, cavitation occurs in PDCV due to the use of high pressure DH water. It causes frequent failures, many problems and energy losses. It makes a complaint to both the operator and the user. In order to solve these problems, we have introduced the hydroelectric power generation method to replace PDCV with hydraulic turbine, convert the unused Differential pressure within a DH pipe into electricity. When a Differential pressure power generation system is operated in the user’s substation, power generation of about 10 to 20 MWh and reduction of carbon dioxide emission to about 7 tons can be seen for a year. It is possible to install more than 3,000 out of about 10,000 of the district heating in Korea. It can grow into a new energy business model. It is also calculated that the DH plant has a power saving effect. The cost of the DH pump power can reduce by more than 3%, and the efficiency of CHP plant can increase by more than 0.3% because 10% defective of PDCV is decreased.

  • Hydroelectric Power Generation Using Differential Pressure of District Heating Pipe in a Thermal Grid
    2017 4th Asia-Pacific World Congress on Computer Science and Engineering (APWC on CSE), 2017
    Co-Authors: Mun Sei Oh, Sung Yong Park
    Abstract:

    When the hot water for district heating (DH) is supplied through a thermal grid, a pressure Differential Control Valve (PDCV) in a substation protects the users’ equipment from the high pressure water and helps to supply DH water to long distance. It also Controls the constant temperature and adjusts the constant pressure in the thermal grid. However, cavitation occurs in PDCV due to the use of high pressure DH water. It causes frequent failures, many problems and energy losses. It makes a complaint to both the operator and the user. In order to solve these problems, we will introduce the hydroelectric power generation method to replace PDCV with hydraulic turbine, convert the unused Differential pressure within a DH pipe into electricity.

Haojie Ye - One of the best experts on this subject based on the ideXlab platform.

  • Numerical Analysis on Cavitation Erosion of a High Pressure Differential Control Valve
    Volume 3: Design and Analysis, 2016
    Co-Authors: Zhijian Zheng, Guofu Ou, Haojie Ye
    Abstract:

    The numerical simulation on the cavitation erosion of a high pressure Differential Control Valve is conducted. The characteristic of cavitation flow is obtained by using full cavitation model and RNG k-ε turbulence model with actual operational conditions and fluid physical parameters. Results showed that: the flow velocity increases rapidly as the fluid passes through the gap between the Valve spool and seat. Simultaneously the local static pressure decreases below the saturation pressure of the fluid, then the cavitation is formed. For the convergent - expansion structure, the flow separation occurs due to the pressure recovery, which leads to the formation of recirculation zone, where the cavitation cloud appears. The increases of fluid temperature and inlet pressure or the decreases of Valve spool angle and Valve opening result in the enlargement of cavitation area and enhancement of cavitation intensity. The numerical simulation results correlate well with actual failure morphologies, which proves that the method can be successfully applied in the cavitation prediction of a high pressure Differential Control Valve.