The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Hua Tian - One of the best experts on this subject based on the ideXlab platform.
-
theoretical analysis and comparison of rankine cycle and different organic rankine cycles as waste heat recovery system for a large Gaseous Fuel internal combustion engine
Applied Thermal Engineering, 2016Co-Authors: Xuan Wang, Hua TianAbstract:Abstract As oil crisis and environment pollution problem become increasingly prominent, Gaseous Fuel internal combustion engines (gas engines) have been valued more and more because of the great resources potential and the feature of low pollution of Gaseous Fuel. However, their average efficiency is just about 30–40% wasting large amount of energy by exhaust, cooling water and so on. Therefore, it is an effective way of improving the efficiency to recover waste heat. Both the RC (steam Rankine Cycle) and the ORC (Organic Rankine Cycle) are considered as quite suitable methods of WHR (waste heat recovery), especially for large engines. As the WHR system for a specific large gas engine, RC and ORC both have advantages and disadvantages. A gas engine of rated power 1000 kW is the studied object in this paper. According to the characters of its waste heat, the WHR systems of RC and ORC with different working fluids, including a two-stage Organic Rankine Cycle (DORC) are built in math model and they are compared from the aspects of recovered power, thermal efficiency, system feasibility and so on, which provides a reference for the engineering application. Finally, the economic performance of ORC, RC and DORC are evaluated and compared.
-
part load performance prediction and operation strategy design of organic rankine cycles with a medium cycle used for recovering waste heat from Gaseous Fuel engines
Energies, 2016Co-Authors: Xuan Wang, Hua TianAbstract:The Organic Rankine Cycle (ORC) is regarded as a suitable way to recover waste heat from Gaseous Fuel internal combustion engines. As waste heat recovery systems (WHRS) have always been designed based on rated working conditions, while engines often work under part-load conditions, it is quite significant to analyze the part-load performance and corresponding operation strategy of ORC systems. This paper presents a dynamic model of ORC with a medium cycle used for a large Gaseous Fuel engine and analyzes the effect of adjustable parameters on the system performance, giving effective control directions under various conditions. The results indicate that the intermediary fluid mass flow rate has nearly no effect on the output power and thermal efficiency of the ORC, while the mass flow rate of working fluid has a great effect on them. In order to get a better system performance under different working conditions, the system should be operated with the working fluid mass flow rate as large as possible, but with a slight degree of superheating. Then, with the control of constant superheat degree at the end of the heating process, the performance of the combined system that consists of ORC and the engine at steady state under seven typical working conditions is also analyzed. The results indicate that the energy-saving effect of WHRS becomes worse and worse as the working condition decreases. Especially at 40% working condition the WHRS nearly has no energy-saving effect anymore.
-
analysis of an electricity cooling cogeneration system for waste heat recovery of Gaseous Fuel engines
Science China-technological Sciences, 2015Co-Authors: Xuan Wang, Hua Tian, Youcai LiangAbstract:Waste heat recovery (WHR) is one of the most useful ways to improve the efficiency of internal combustion engines, and an electricity-cooling cogeneration system (ECCS) based on Rankin-absorption refrigeration combined cycle for the WHR of Gaseous Fuel engines is proposed in the paper. This system can avoid wasting the heat in condenser so that the efficiency of the whole WHR system improves, but the condensing temperature of Rankin cycle (RC) must increase in order to use absorption refrigeration system, which leads to the decrease of RC output power. Therefore, the relationship between the profit of absorption refrigeration system and the loss of RC in this combined system is the mainly studied content in the paper. Because the energy quality of cooling and electricity are different, cooling power in absorption refrigeration is converted to corresponding electrical power consumed by electric cooling system, which is defined as equivalent electrical power. With this method, the effects of some important operation parameters on the performance of the ECCS are researched, and the equivalent efficiency, exergy efficiency and primary energy rate are compared in the paper.
Xuan Wang - One of the best experts on this subject based on the ideXlab platform.
-
theoretical analysis and comparison of rankine cycle and different organic rankine cycles as waste heat recovery system for a large Gaseous Fuel internal combustion engine
Applied Thermal Engineering, 2016Co-Authors: Xuan Wang, Hua TianAbstract:Abstract As oil crisis and environment pollution problem become increasingly prominent, Gaseous Fuel internal combustion engines (gas engines) have been valued more and more because of the great resources potential and the feature of low pollution of Gaseous Fuel. However, their average efficiency is just about 30–40% wasting large amount of energy by exhaust, cooling water and so on. Therefore, it is an effective way of improving the efficiency to recover waste heat. Both the RC (steam Rankine Cycle) and the ORC (Organic Rankine Cycle) are considered as quite suitable methods of WHR (waste heat recovery), especially for large engines. As the WHR system for a specific large gas engine, RC and ORC both have advantages and disadvantages. A gas engine of rated power 1000 kW is the studied object in this paper. According to the characters of its waste heat, the WHR systems of RC and ORC with different working fluids, including a two-stage Organic Rankine Cycle (DORC) are built in math model and they are compared from the aspects of recovered power, thermal efficiency, system feasibility and so on, which provides a reference for the engineering application. Finally, the economic performance of ORC, RC and DORC are evaluated and compared.
-
part load performance prediction and operation strategy design of organic rankine cycles with a medium cycle used for recovering waste heat from Gaseous Fuel engines
Energies, 2016Co-Authors: Xuan Wang, Hua TianAbstract:The Organic Rankine Cycle (ORC) is regarded as a suitable way to recover waste heat from Gaseous Fuel internal combustion engines. As waste heat recovery systems (WHRS) have always been designed based on rated working conditions, while engines often work under part-load conditions, it is quite significant to analyze the part-load performance and corresponding operation strategy of ORC systems. This paper presents a dynamic model of ORC with a medium cycle used for a large Gaseous Fuel engine and analyzes the effect of adjustable parameters on the system performance, giving effective control directions under various conditions. The results indicate that the intermediary fluid mass flow rate has nearly no effect on the output power and thermal efficiency of the ORC, while the mass flow rate of working fluid has a great effect on them. In order to get a better system performance under different working conditions, the system should be operated with the working fluid mass flow rate as large as possible, but with a slight degree of superheating. Then, with the control of constant superheat degree at the end of the heating process, the performance of the combined system that consists of ORC and the engine at steady state under seven typical working conditions is also analyzed. The results indicate that the energy-saving effect of WHRS becomes worse and worse as the working condition decreases. Especially at 40% working condition the WHRS nearly has no energy-saving effect anymore.
-
analysis of an electricity cooling cogeneration system for waste heat recovery of Gaseous Fuel engines
Science China-technological Sciences, 2015Co-Authors: Xuan Wang, Hua Tian, Youcai LiangAbstract:Waste heat recovery (WHR) is one of the most useful ways to improve the efficiency of internal combustion engines, and an electricity-cooling cogeneration system (ECCS) based on Rankin-absorption refrigeration combined cycle for the WHR of Gaseous Fuel engines is proposed in the paper. This system can avoid wasting the heat in condenser so that the efficiency of the whole WHR system improves, but the condensing temperature of Rankin cycle (RC) must increase in order to use absorption refrigeration system, which leads to the decrease of RC output power. Therefore, the relationship between the profit of absorption refrigeration system and the loss of RC in this combined system is the mainly studied content in the paper. Because the energy quality of cooling and electricity are different, cooling power in absorption refrigeration is converted to corresponding electrical power consumed by electric cooling system, which is defined as equivalent electrical power. With this method, the effects of some important operation parameters on the performance of the ECCS are researched, and the equivalent efficiency, exergy efficiency and primary energy rate are compared in the paper.
Jerry D Murphy - One of the best experts on this subject based on the ideXlab platform.
-
potential of seaweed as a feedstock for renewable Gaseous Fuel production in ireland
Renewable & Sustainable Energy Reviews, 2017Co-Authors: Muhammad Rizwan Tabassum, Jerry D MurphyAbstract:Resource depletion and mitigation of climate change are the driving forces to find alternatives to fossil Fuels. Seaweeds (macroalgae) have been considered as a promising alternative source of bioFuels due to higher growth rates, greater production yields and a higher rate of carbon dioxide fixation, than land crops. A comparatively easily depolymerized structure, lack of need of arable land and no fresh water requirement for cultivation, make seaweed a potential feedstock for Gaseous bioFuel production. Biomethane potential of seaweed is greatly dependent on its chemical composition that is highly variable due to its type, habitat, cultivation method and time of harvest. Saccharina latissima and Laminaria digitata are the highest biomethane yielding Irish brown seaweeds. Seaweed harvested in July (northern hemisphere) was estimated to give gross energy yields in the range 38–384 GJ ha−1 yr−1; higher values are dependent on innovative cultivation systems. An integrated model is suggested where seaweed can be co-digested with other feedstock for the sustainable production of Gaseous Fuel to facilitate EU renewable energy targets in transport.
-
potential of seaweed as a feedstock for renewable Gaseous Fuel production in ireland
Renewable & Sustainable Energy Reviews, 2017Co-Authors: Muhammad Rizwan Tabassum, Ao Xia, Jerry D MurphyAbstract:Resource depletion and mitigation of climate change are the driving forces to find alternatives to fossil Fuels. Seaweeds (macroalgae) have been considered as a promising alternative source of bioFuels due to higher growth rates, greater production yields and a higher rate of carbon dioxide fixation, than land crops. A comparatively easily depolymerized structure, lack of need of arable land and no fresh water requirement for cultivation, make seaweed a potential feedstock for Gaseous bioFuel production. Biomethane potential of seaweed is greatly dependent on its chemical composition that is highly variable due to its type, habitat, cultivation method and time of harvest. Saccharina latissima and Laminaria digitata are the highest biomethane yielding Irish brown seaweeds. Seaweed harvested in July (northern hemisphere) was estimated to give gross energy yields in the range 38–384 GJ ha−1 yr−1; higher values are dependent on innovative cultivation systems. An integrated model is suggested where seaweed can be co-digested with other feedstock for the sustainable production of Gaseous Fuel to facilitate EU renewable energy targets in transport.
Su Shiung Lam - One of the best experts on this subject based on the ideXlab platform.
-
Progress in waste valorization using advanced pyrolysis techniques for hydrogen and Gaseous Fuel production.
Bioresource technology, 2020Co-Authors: Shin Ying Foong, Yi Herng Chan, Wai Yan Cheah, Noor Haziqah Kamaludin, Tengku Nilam Baizura Tengku Ibrahim, Christian Sonne, Wanxi Peng, Pau Loke Show, Su Shiung LamAbstract:Abstract Hydrogen and Gaseous Fuel derived from wastes have opened up promising alternative pathways for the production of renewable and sustainable Fuels to substitute classical fossil energy resources that cause global warming and pollution. Existing review articles focus mostly on gasification, reforming and pyrolysis processes, with limited information on particularly Gaseous Fuel production via pyrolysis of various waste products. This review provides an overview on the recent advanced pyrolysis technology used in hydrogen and Gaseous Fuel production. The key parameters to maximize the production of specific compounds were discussed. More studies are needed to optimize the process parameters and improve the understanding of reaction mechanisms and co-relationship between these advanced techniques. These advanced techniques provide novel environmentally sustainable and commercially procedures for waste-based production of hydrogen and Gaseous Fuels.
Ujjwal K Saha - One of the best experts on this subject based on the ideXlab platform.
-
effect of engine parameters and type of Gaseous Fuel on the performance of dual Fuel gas diesel engines a critical review
Renewable & Sustainable Energy Reviews, 2009Co-Authors: Bibhuti B Sahoo, Niranjan Sahoo, Ujjwal K SahaAbstract:Petroleum resources are finite and, therefore, search for their alternative non-petroleum Fuels for internal combustion engines is continuing all over the world. Moreover gases emitted by petroleum Fuel driven vehicles have an adverse effect on the environment and human health. There is universal acceptance of the need to reduce such emissions. Towards this, scientists have proposed various solutions for diesel engines, one of which is the use of Gaseous Fuels as a supplement for liquid diesel Fuel. These engines, which use conventional diesel Fuel and Gaseous Fuel, are referred to as 'dual-Fuel engines'. Natural gas and bio-derived gas appear more attractive alternative Fuels for dual-Fuel engines in view of their friendly environmental nature. In the gas-fumigated dual-Fuel engine, the primary Fuel is mixed outside the cylinder before it is inducted into the cylinder. A pilot quantity of liquid Fuel is injected towards the end of the compression stroke to initiate combustion. When considering a Gaseous Fuel for use in existing diesel engines, a number of issues which include, the effects of engine operating and design parameters, and type of Gaseous Fuel, on the performance of the dual-Fuel engines, are important. This paper reviews the research on above issues carried out by various scientists in different diesel engines. This paper touches upon performance, combustion and emission characteristics of dual-Fuel engines which use natural gas, biogas, producer gas, methane, liquefied petroleum gas, propane, etc. as Gaseous Fuel. It reveals that 'dual-Fuel concept' is a promising technique for controlling both NOx and soot emissions even on existing diesel engine. But, HC, CO emissions and 'bsfc' are higher for part load gas diesel engine operations. Thermal efficiency of dual-Fuel engines improve either with increased engine speed, or with advanced injection timings, or with increased amount of pilot Fuel. The ignition characteristics of the Gaseous Fuels need more research for a long-term use in a dual-Fuel engine. It is found that, the selection of engine operating and design parameters play a vital role in minimizing the performance divergences between an existing diesel engine and a 'gas diesel engine'.
-
Effect of engine parameters and type of Gaseous Fuel on the performance of dual-Fuel gas diesel engines—A critical review
Renewable & Sustainable Energy Reviews, 2008Co-Authors: Bibhuti B Sahoo, Niranjan Sahoo, Ujjwal K SahaAbstract:Abstract Petroleum resources are finite and, therefore, search for their alternative non-petroleum Fuels for internal combustion engines is continuing all over the world. Moreover gases emitted by petroleum Fuel driven vehicles have an adverse effect on the environment and human health. There is universal acceptance of the need to reduce such emissions. Towards this, scientists have proposed various solutions for diesel engines, one of which is the use of Gaseous Fuels as a supplement for liquid diesel Fuel. These engines, which use conventional diesel Fuel and Gaseous Fuel, are referred to as ‘dual-Fuel engines’. Natural gas and bio-derived gas appear more attractive alternative Fuels for dual-Fuel engines in view of their friendly environmental nature. In the gas-fumigated dual-Fuel engine, the primary Fuel is mixed outside the cylinder before it is inducted into the cylinder. A pilot quantity of liquid Fuel is injected towards the end of the compression stroke to initiate combustion. When considering a Gaseous Fuel for use in existing diesel engines, a number of issues which include, the effects of engine operating and design parameters, and type of Gaseous Fuel, on the performance of the dual-Fuel engines, are important. This paper reviews the research on above issues carried out by various scientists in different diesel engines. This paper touches upon performance, combustion and emission characteristics of dual-Fuel engines which use natural gas, biogas, producer gas, methane, liquefied petroleum gas, propane, etc. as Gaseous Fuel. It reveals that ‘dual-Fuel concept’ is a promising technique for controlling both NOx and soot emissions even on existing diesel engine. But, HC, CO emissions and ‘bsfc’ are higher for part load gas diesel engine operations. Thermal efficiency of dual-Fuel engines improve either with increased engine speed, or with advanced injection timings, or with increased amount of pilot Fuel. The ignition characteristics of the Gaseous Fuels need more research for a long-term use in a dual-Fuel engine. It is found that, the selection of engine operating and design parameters play a vital role in minimizing the performance divergences between an existing diesel engine and a ‘gas diesel engine’.
