The Experts below are selected from a list of 366 Experts worldwide ranked by ideXlab platform

Long Jiang - One of the best experts on this subject based on the ideXlab platform.

  • Exergy analysis of the turbine system in a 1000 MW double reheat ultra-supercritical power plant
    Energy, 2017
    Co-Authors: Zhigang Zhao, Yi Wang, Xu Jun, Long Jiang, Gang Chen, Jun Xiang
    Abstract:

    This study aims to achieve Exergy distribution in a turbine system for a 1000 MW double reheat ultra-supercritical power plant. An Exergy Balance Equation is used to identify the real points of energy loss in the turbine system, which can provide a reference for optimizing operation and conserving energy. Results show that irreversibilities yield the highest Exergy loss in the turbine, particularly in the very high pressure (VHP) and low pressure (LP) cylinders. Compared with that in the turbine of a single reheat unit, Exergy loss in the studied turbine is higher and Exergy efficiency is lower. For the regenerative system, Exergy loss is lower and Exergy efficiency is higher in the double reheat unit than in the single reheat unit. Thus, the layout of the regenerative heaters in the double reheat unit is more reasonable. However, Exergy loss in high pressure regenerative heater Nos. 3 and 6 and low pressure regenerative heater Nos. 7 and 10 in the heat recovery system is extraordinary because of different reasons. Exergy loss in the condenser of the double reheat unit is relatively smaller than that in the condenser of the single reheat unit.

  • Exergy analysis of a 1000 MW double reheat ultra-supercritical power plant
    Energy Conversion and Management, 2017
    Co-Authors: Zhigang Zhao, Yi Wang, Xu Jun, Pengshuai Han, Zhijun Sun, Cui Xiaoning, Long Jiang
    Abstract:

    Abstract This study evaluates the performance of a 1000 MW double reheat ultra-supercritical power plant. An Exergy analysis was performed to direct the energy loss distribution of this system. Based on the Exergy Balance Equation, together with Exergy efficiency, Exergy loss coefficient, and Exergy loss rate, the Exergy distribution and efficiency of the unit were determined. Results show that the highest Exergy loss in furnace is as high as 85%, which caused by the combustion of fuel and heat exchange of water wall. The VHP and the two LPs suffer the highest Exergy losses, namely 1.86%, 2.04% and 2.13% respectively. The regenerative heating system has an Exergy loss rate of 2.3%. The condenser suffers a heat loss of 999 MW, but its Exergy is as low as 20.49 MW. The sensitivity variations of the unit’s Exergy efficiency with load, feedwater temperature, main steam temperature and pressure, the twice reheat steam temperatures, and steam exhaust pressure were also analyzed, indicating that load, feedwater temperature, and steam exhaust pressure influence the Exergy efficiency of this unit than other elements. The overall Exergy efficiency decreases along with the gradual increase of steam exhaust pressure at any constant outlet boiler temperature, but it increases as the load, feedwater temperature, main steam temperature and pressure, and twice reheat steam temperatures increase at fixed steam exhaust pressure.

Zhigang Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Exergy analysis of the turbine system in a 1000 MW double reheat ultra-supercritical power plant
    Energy, 2017
    Co-Authors: Zhigang Zhao, Yi Wang, Xu Jun, Long Jiang, Gang Chen, Jun Xiang
    Abstract:

    This study aims to achieve Exergy distribution in a turbine system for a 1000 MW double reheat ultra-supercritical power plant. An Exergy Balance Equation is used to identify the real points of energy loss in the turbine system, which can provide a reference for optimizing operation and conserving energy. Results show that irreversibilities yield the highest Exergy loss in the turbine, particularly in the very high pressure (VHP) and low pressure (LP) cylinders. Compared with that in the turbine of a single reheat unit, Exergy loss in the studied turbine is higher and Exergy efficiency is lower. For the regenerative system, Exergy loss is lower and Exergy efficiency is higher in the double reheat unit than in the single reheat unit. Thus, the layout of the regenerative heaters in the double reheat unit is more reasonable. However, Exergy loss in high pressure regenerative heater Nos. 3 and 6 and low pressure regenerative heater Nos. 7 and 10 in the heat recovery system is extraordinary because of different reasons. Exergy loss in the condenser of the double reheat unit is relatively smaller than that in the condenser of the single reheat unit.

  • Exergy analysis of a 1000 MW double reheat ultra-supercritical power plant
    Energy Conversion and Management, 2017
    Co-Authors: Zhigang Zhao, Yi Wang, Xu Jun, Pengshuai Han, Zhijun Sun, Cui Xiaoning, Long Jiang
    Abstract:

    Abstract This study evaluates the performance of a 1000 MW double reheat ultra-supercritical power plant. An Exergy analysis was performed to direct the energy loss distribution of this system. Based on the Exergy Balance Equation, together with Exergy efficiency, Exergy loss coefficient, and Exergy loss rate, the Exergy distribution and efficiency of the unit were determined. Results show that the highest Exergy loss in furnace is as high as 85%, which caused by the combustion of fuel and heat exchange of water wall. The VHP and the two LPs suffer the highest Exergy losses, namely 1.86%, 2.04% and 2.13% respectively. The regenerative heating system has an Exergy loss rate of 2.3%. The condenser suffers a heat loss of 999 MW, but its Exergy is as low as 20.49 MW. The sensitivity variations of the unit’s Exergy efficiency with load, feedwater temperature, main steam temperature and pressure, the twice reheat steam temperatures, and steam exhaust pressure were also analyzed, indicating that load, feedwater temperature, and steam exhaust pressure influence the Exergy efficiency of this unit than other elements. The overall Exergy efficiency decreases along with the gradual increase of steam exhaust pressure at any constant outlet boiler temperature, but it increases as the load, feedwater temperature, main steam temperature and pressure, and twice reheat steam temperatures increase at fixed steam exhaust pressure.

Qinglin Cheng - One of the best experts on this subject based on the ideXlab platform.

  • studies of the unavoidable Exergy loss rate and analysis of influence parameters for pipeline transportation process
    Case Studies in Thermal Engineering, 2018
    Co-Authors: Qinglin Cheng, Anbo Zheng, Hao Wu, Lu Yang, Lili Lv
    Abstract:

    Abstract According to the Exergy Balance relationship among the various items in the crude oil transportation process system, the Exergy Balance Equation is established and each Exergy loss is calculated. In a sense, the essence of Exergy analysis method relies on the calculation and the analysis of system Exergy loss. The unavoidable Exergy loss is defined based on the required minimum Exergy loss from the technology standpoint during the pipeline conveying process. In order to truly reflect the degree of effective energy utilization, this article puts forward the unavoidable Exergy loss rate as evaluation index, which is based on the Exergy analysis criterion consisted by Exergy loss coefficient and Exergy loss rate. Taking an oil pipeline as an example, the changes of the unavoidable Exergy loss are studied under different designed parameters. And the unavoidable thermal Exergy loss is the dominant position. Change situations of the unavoidable Exergy loss rate are explored. Through analysis, the trend and the regularity of the unavoidable total Exergy loss rate are identical with the unavoidable thermal Exergy loss rate. Then the orthogonal experiment method is used to compare the different influence degrees to the pipeline unavoidable Exergy loss rate. The results are as follows: diameter, insulation thickness and buried depth, which can provide the reference for the energy-saving transportation of crude oil pipeline.

  • Studies on the Exergy Transfer Law for the Irreversible Process in the Waxy Crude Oil Pipeline Transportation
    Entropy (Basel Switzerland), 2018
    Co-Authors: Qinglin Cheng, Anbo Zheng, Shuang Song, Yang Liu
    Abstract:

    With the increasing demand of oil products in China, the energy consumption of pipeline operation will continue to rise greatly, as well as the cost of oil transportation. In the field of practical engineering, saving energy, reducing energy consumption and adapting to the international oil situation are the development trends and represent difficult problems. Based on the basic principle of non-equilibrium thermodynamics, this paper derives the field equilibrium Equations of non-equilibrium thermodynamic process for pipeline transportation. To seek the bilinear form of “force” and “flow” in the non-equilibrium thermodynamics of entropy generation rate, the oil pipeline Exergy Balance Equation and the Exergy transfer pipeline dynamic Equation of the irreversibility were established. The Exergy Balance Equation was applied to energy Balance evaluation system, which makes the system more perfect. The Exergy flow transfer law of the waxy oil pipeline were explored deeply from the directions of dynamic Exergy, pressure Exergy, thermal Exergy and diffusion Exergy. Taking an oil pipeline as an example, the influence factors of Exergy transfer coefficient and Exergy flow density were analyzed separately.

  • Studies of the unavoidable Exergy loss rate and analysis of influence parameters for pipeline transportation process
    Elsevier, 2018
    Co-Authors: Qinglin Cheng, Anbo Zheng, Lu Yang, Hongjun Xie, Yang Liu
    Abstract:

    According to the Exergy Balance relationship among the various items in the crude oil transportation process system, the Exergy Balance Equation is established and each Exergy loss is calculated. In a sense, the essence of Exergy analysis method relies on the calculation and the analysis of system Exergy loss. The unavoidable Exergy loss is defined based on the required minimum Exergy loss from the technology standpoint during the pipeline conveying process. In order to truly reflect the degree of effective energy utilization, this article puts forward the unavoidable Exergy loss rate as evaluation index, which is based on the Exergy analysis criterion consisted by Exergy loss coefficient and Exergy loss rate. Taking an oil pipeline as an example, the changes of the unavoidable Exergy loss are studied under different designed parameters. And the unavoidable thermal Exergy loss is the dominant position. Change situations of the unavoidable Exergy loss rate are explored. Through analysis, the trend and the regularity of the unavoidable total Exergy loss rate are identical with the unavoidable thermal Exergy loss rate. Then the orthogonal experiment method is used to compare the different influence degrees to the pipeline unavoidable Exergy loss rate. The results are as follows: diameter, insulation thickness and buried depth, which can provide the reference for the energy-saving transportation of crude oil pipeline. Keywords: Unavoidable Exergy loss, Exergy analysis criterion, Unavoidable Exergy loss rate, Orthogonal experimen

Lili Lv - One of the best experts on this subject based on the ideXlab platform.

  • studies of the unavoidable Exergy loss rate and analysis of influence parameters for pipeline transportation process
    Case Studies in Thermal Engineering, 2018
    Co-Authors: Qinglin Cheng, Anbo Zheng, Hao Wu, Lu Yang, Lili Lv
    Abstract:

    Abstract According to the Exergy Balance relationship among the various items in the crude oil transportation process system, the Exergy Balance Equation is established and each Exergy loss is calculated. In a sense, the essence of Exergy analysis method relies on the calculation and the analysis of system Exergy loss. The unavoidable Exergy loss is defined based on the required minimum Exergy loss from the technology standpoint during the pipeline conveying process. In order to truly reflect the degree of effective energy utilization, this article puts forward the unavoidable Exergy loss rate as evaluation index, which is based on the Exergy analysis criterion consisted by Exergy loss coefficient and Exergy loss rate. Taking an oil pipeline as an example, the changes of the unavoidable Exergy loss are studied under different designed parameters. And the unavoidable thermal Exergy loss is the dominant position. Change situations of the unavoidable Exergy loss rate are explored. Through analysis, the trend and the regularity of the unavoidable total Exergy loss rate are identical with the unavoidable thermal Exergy loss rate. Then the orthogonal experiment method is used to compare the different influence degrees to the pipeline unavoidable Exergy loss rate. The results are as follows: diameter, insulation thickness and buried depth, which can provide the reference for the energy-saving transportation of crude oil pipeline.

Yi Wang - One of the best experts on this subject based on the ideXlab platform.

  • Exergy analysis of the turbine system in a 1000 MW double reheat ultra-supercritical power plant
    Energy, 2017
    Co-Authors: Zhigang Zhao, Yi Wang, Xu Jun, Long Jiang, Gang Chen, Jun Xiang
    Abstract:

    This study aims to achieve Exergy distribution in a turbine system for a 1000 MW double reheat ultra-supercritical power plant. An Exergy Balance Equation is used to identify the real points of energy loss in the turbine system, which can provide a reference for optimizing operation and conserving energy. Results show that irreversibilities yield the highest Exergy loss in the turbine, particularly in the very high pressure (VHP) and low pressure (LP) cylinders. Compared with that in the turbine of a single reheat unit, Exergy loss in the studied turbine is higher and Exergy efficiency is lower. For the regenerative system, Exergy loss is lower and Exergy efficiency is higher in the double reheat unit than in the single reheat unit. Thus, the layout of the regenerative heaters in the double reheat unit is more reasonable. However, Exergy loss in high pressure regenerative heater Nos. 3 and 6 and low pressure regenerative heater Nos. 7 and 10 in the heat recovery system is extraordinary because of different reasons. Exergy loss in the condenser of the double reheat unit is relatively smaller than that in the condenser of the single reheat unit.

  • Exergy analysis of a 1000 MW double reheat ultra-supercritical power plant
    Energy Conversion and Management, 2017
    Co-Authors: Zhigang Zhao, Yi Wang, Xu Jun, Pengshuai Han, Zhijun Sun, Cui Xiaoning, Long Jiang
    Abstract:

    Abstract This study evaluates the performance of a 1000 MW double reheat ultra-supercritical power plant. An Exergy analysis was performed to direct the energy loss distribution of this system. Based on the Exergy Balance Equation, together with Exergy efficiency, Exergy loss coefficient, and Exergy loss rate, the Exergy distribution and efficiency of the unit were determined. Results show that the highest Exergy loss in furnace is as high as 85%, which caused by the combustion of fuel and heat exchange of water wall. The VHP and the two LPs suffer the highest Exergy losses, namely 1.86%, 2.04% and 2.13% respectively. The regenerative heating system has an Exergy loss rate of 2.3%. The condenser suffers a heat loss of 999 MW, but its Exergy is as low as 20.49 MW. The sensitivity variations of the unit’s Exergy efficiency with load, feedwater temperature, main steam temperature and pressure, the twice reheat steam temperatures, and steam exhaust pressure were also analyzed, indicating that load, feedwater temperature, and steam exhaust pressure influence the Exergy efficiency of this unit than other elements. The overall Exergy efficiency decreases along with the gradual increase of steam exhaust pressure at any constant outlet boiler temperature, but it increases as the load, feedwater temperature, main steam temperature and pressure, and twice reheat steam temperatures increase at fixed steam exhaust pressure.