There are several ways to increase the efficiency of energy consumption and to decrease energy consumption. In this paper. the application of pinch technology in analysis of the heat exchangers network （HEN） in orde...There are several ways to increase the efficiency of energy consumption and to decrease energy consumption. In this paper. the application of pinch technology in analysis of the heat exchangers network （HEN） in order to reduce the energy consumption in a thermal system is studied. Therefore, in this grass root design, the optimum value of △Tmin, is obtained about 10℃and area efficiency （a） is 0.95. The author also depicted the grid diagram and driving force plot for additional analysis. In order to increase the amount of energy saving, heat transfer from above to below the pinch point in the diagnosis stage is verified for all options including re-sequencing, re-piping, add heat exchanger and splitting of the flows. Results show that this network has a low potential of retrofit to decrease the energy consumption, which pinch principles are planned to optimize energy consumption of the unit. Regarding the results of pinch analysis, it is suggested that in order to reduce the energy consumption, no alternative changes in the heat exchangers network of the unit is required. The acquired results show that the constancy of network is completely confirmed by the high area efficiency infirmity of the heat exchanger to pass the pinch point and from of deriving force plot.展开更多
An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more...An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more importantly its high cost.The recovery of internal waste heat becomes therefore very important in order to improve the coefficient of performance(COP).Analysis based on pinch technology can be helpful to optimal heat recovery operation.In this paper,temperature-heat diagrams and problem tables for adsorption refrigeration systems are proposed and analyzed using Pinch Technology.The results show that pinch point is located between beds and the main waste heat needs to be recovered between beds.Dynamic characteristic(time factor)of adsorption refrigeration system is the main resistance for heat recovery.The effect of pinch point temperature difference on the system COP is not distinct.Furthermore,when the driving temperature is 90°C,the COP of adsorption refrigeration via optimization of pinch analysis is 0.73 which is fairly comparable to Li Br-water absorption refrigeration system.Pinch Technology can be adopted in different types of adsorption refrigeration systems(two-bed,four-bed,mass recovery,et al.).展开更多
In this paper, the research was focused on optimizing low-temperature heat recovery to adopt multi-effect distil- lation （MED） in desalination by pinch technology. And further analysis indicated that phase changes o...In this paper, the research was focused on optimizing low-temperature heat recovery to adopt multi-effect distil- lation （MED） in desalination by pinch technology. And further analysis indicated that phase changes occurred during the heat recovery process. In such case, the feed stream was divided into two streams： the liquid feed stream and the gaseous feed stream. Through calculation, the optimal ATmin was established at 26℃, and the total cost of heat exchange process was only $1.098× 106. By using the Problem Table Algorithm for pinch analysis, the temperature of the hot and the cold steams was 119℃ and 93 ℃, respectively. At a temperature higher than 119 ℃, all heat of the hot stream could not be cooled by the condenser, and the minimum heat load of utility （QH.min） was 440457.64 kW; and at a temperature below 93 ℃, all heat of the cold stream could not be provided by the heater, and the minimum cold load of utility （QC.min） was 1965993.85 kW. Finally, the synthesis of heat exchanger network was established through integrating two heat exchanger networks.展开更多
In refineries,some hydrogen-rich streams contain considerable light hydrocarbons that are important raw materials for the chemical industry.Integrating hydrogen networks with light hydrocarbon recovery can enhance the...In refineries,some hydrogen-rich streams contain considerable light hydrocarbons that are important raw materials for the chemical industry.Integrating hydrogen networks with light hydrocarbon recovery can enhance the reuse of both hydrogen and light hydrocarbons.This work proposes an automated method for targeting hydrogen networks with light hydrocarbon recovery.A pinch-based algebraic method is improved to determine the minimum fresh hydrogen consumption and hydrogen sources fed into the light hydrocarbon recovery unit automatically.Rigorous process simulation is conducted to determine the mass and energy balances of the light hydrocarbon recovery process.The targeting procedures are developed through combination of the improved pinch method and rigorous process simulation.This hybrid method is realized by coupling the Matlab and Aspen HYSYS platforms.A refinery hydrogen network is analyzed to illustrate application of the proposed method.The integration of hydrogen network with light hydrocarbon recovery further reduces fresh hydrogen requirement by463.0 m^(3)·h^(-1) and recovers liquefied petroleum gas and gasoline of 1711.5 kg·h^(-1) and 643 kg·h^(-1),respectively.A payback period of 9.2 months indicates that investment in light hydrocarbon recovery is economically attractive.展开更多
The heat exchanger network(HEN)in a syngas-to-methanol process was designed and optimized based on pinch technology under stable operating conditions to balance the energy consumption and economic gain.In actual indus...The heat exchanger network(HEN)in a syngas-to-methanol process was designed and optimized based on pinch technology under stable operating conditions to balance the energy consumption and economic gain.In actual industrial processes,fluctuations in production inevitably affect the stable operation of HENs.A flexibility analysis of the HEN was carried out to minimize such disturbances using the downstream paths method.The results show that two-third of the downstream paths cannot meet flexibility requirements,indicating that the HEN does not have enough flexibility to accommodate the disturbances in actual production.A flexible HEN was then designed with the method of dividing and subsequent merging of streams,which led to 13.89%and 20.82%reductions in energy consumption and total cost,respectively.Owing to the sufficient area margin and additional alternative heat exchangers,the flexible HEN was able to resist interference and maintain production stability and safety,with the total cost increasing by just 4.08%.展开更多
This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utiliz...This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utilization systems were first divided into three groups, then water-supply priority algorithm was proposed. The results of case studies showed that the water networks designed by this method gave water consumption lower than that estimated by other approaches. In addition, the procedure was subject to no limitation on the problem scale.展开更多
文摘There are several ways to increase the efficiency of energy consumption and to decrease energy consumption. In this paper. the application of pinch technology in analysis of the heat exchangers network （HEN） in order to reduce the energy consumption in a thermal system is studied. Therefore, in this grass root design, the optimum value of △Tmin, is obtained about 10℃and area efficiency （a） is 0.95. The author also depicted the grid diagram and driving force plot for additional analysis. In order to increase the amount of energy saving, heat transfer from above to below the pinch point in the diagnosis stage is verified for all options including re-sequencing, re-piping, add heat exchanger and splitting of the flows. Results show that this network has a low potential of retrofit to decrease the energy consumption, which pinch principles are planned to optimize energy consumption of the unit. Regarding the results of pinch analysis, it is suggested that in order to reduce the energy consumption, no alternative changes in the heat exchangers network of the unit is required. The acquired results show that the constancy of network is completely confirmed by the high area efficiency infirmity of the heat exchanger to pass the pinch point and from of deriving force plot.
基金supported by the National Natural Science Foundation of China(Grant No.51906136)the Institute of Advanced Studies(IAS)of the University of Warwick in the UK(Grant No C5E3X56470T)Shanghai Sailing Program(Grant No.19YF1423100)。
文摘An adsorption refrigeration system can be driven by low grade heat and uses natural refrigerant with the advantage of reducing the greenhouse gases emission.However,one of the weaknesses is its low efficiency and more importantly its high cost.The recovery of internal waste heat becomes therefore very important in order to improve the coefficient of performance(COP).Analysis based on pinch technology can be helpful to optimal heat recovery operation.In this paper,temperature-heat diagrams and problem tables for adsorption refrigeration systems are proposed and analyzed using Pinch Technology.The results show that pinch point is located between beds and the main waste heat needs to be recovered between beds.Dynamic characteristic(time factor)of adsorption refrigeration system is the main resistance for heat recovery.The effect of pinch point temperature difference on the system COP is not distinct.Furthermore,when the driving temperature is 90°C,the COP of adsorption refrigeration via optimization of pinch analysis is 0.73 which is fairly comparable to Li Br-water absorption refrigeration system.Pinch Technology can be adopted in different types of adsorption refrigeration systems(two-bed,four-bed,mass recovery,et al.).
基金the National Nature Science Foundation (Grant No. 51178463)
文摘In this paper, the research was focused on optimizing low-temperature heat recovery to adopt multi-effect distil- lation （MED） in desalination by pinch technology. And further analysis indicated that phase changes occurred during the heat recovery process. In such case, the feed stream was divided into two streams： the liquid feed stream and the gaseous feed stream. Through calculation, the optimal ATmin was established at 26℃, and the total cost of heat exchange process was only $1.098× 106. By using the Problem Table Algorithm for pinch analysis, the temperature of the hot and the cold steams was 119℃ and 93 ℃, respectively. At a temperature higher than 119 ℃, all heat of the hot stream could not be cooled by the condenser, and the minimum heat load of utility （QH.min） was 440457.64 kW; and at a temperature below 93 ℃, all heat of the cold stream could not be provided by the heater, and the minimum cold load of utility （QC.min） was 1965993.85 kW. Finally, the synthesis of heat exchanger network was established through integrating two heat exchanger networks.
基金supported by the Fundamental Research Funds for the Central Universities (2020ACOCP04)。
文摘In refineries,some hydrogen-rich streams contain considerable light hydrocarbons that are important raw materials for the chemical industry.Integrating hydrogen networks with light hydrocarbon recovery can enhance the reuse of both hydrogen and light hydrocarbons.This work proposes an automated method for targeting hydrogen networks with light hydrocarbon recovery.A pinch-based algebraic method is improved to determine the minimum fresh hydrogen consumption and hydrogen sources fed into the light hydrocarbon recovery unit automatically.Rigorous process simulation is conducted to determine the mass and energy balances of the light hydrocarbon recovery process.The targeting procedures are developed through combination of the improved pinch method and rigorous process simulation.This hybrid method is realized by coupling the Matlab and Aspen HYSYS platforms.A refinery hydrogen network is analyzed to illustrate application of the proposed method.The integration of hydrogen network with light hydrocarbon recovery further reduces fresh hydrogen requirement by463.0 m^(3)·h^(-1) and recovers liquefied petroleum gas and gasoline of 1711.5 kg·h^(-1) and 643 kg·h^(-1),respectively.A payback period of 9.2 months indicates that investment in light hydrocarbon recovery is economically attractive.
基金This work is financially supported by"the Fundamental Research Funds for the Central Universities"(2020XJHH01)the Yueqi Distinguished Scholar Project of China University of Mining and Technology(Beijing)(2020JCB02).
文摘The heat exchanger network(HEN)in a syngas-to-methanol process was designed and optimized based on pinch technology under stable operating conditions to balance the energy consumption and economic gain.In actual industrial processes,fluctuations in production inevitably affect the stable operation of HENs.A flexibility analysis of the HEN was carried out to minimize such disturbances using the downstream paths method.The results show that two-third of the downstream paths cannot meet flexibility requirements,indicating that the HEN does not have enough flexibility to accommodate the disturbances in actual production.A flexible HEN was then designed with the method of dividing and subsequent merging of streams,which led to 13.89%and 20.82%reductions in energy consumption and total cost,respectively.Owing to the sufficient area margin and additional alternative heat exchangers,the flexible HEN was able to resist interference and maintain production stability and safety,with the total cost increasing by just 4.08%.
文摘This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utilization systems were first divided into three groups, then water-supply priority algorithm was proposed. The results of case studies showed that the water networks designed by this method gave water consumption lower than that estimated by other approaches. In addition, the procedure was subject to no limitation on the problem scale.
