Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice i...Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.展开更多
In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energ^^ of liquefied natural gas （LNG） could be fully utilized as well. A system...In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energ^^ of liquefied natural gas （LNG） could be fully utilized as well. A system simulation and ther^nodynamic analysis were carried out, the Kalina cycle was reorganized by changing the concentration of “basic composition”, so that a better thermal matching in the heat exchanger could be obtained and the irreversibility of the system was decreased. It was found that the Kalina cycle generally used in the bottom of combined power cycle could also be used to recover the cold energy of LNG. The results show that the exergy efficiency of 42.97% is obtained. Compared with the previous system attained the exergy efficiency of 39.76%, the improved system has a better performance.展开更多
In modern times,worldwide requirements to curb greenhouse gas emissions,and increment in energy demand due to the progress of humanity,have become a serious concern.In such scenarios,the effective and efficient utiliz...In modern times,worldwide requirements to curb greenhouse gas emissions,and increment in energy demand due to the progress of humanity,have become a serious concern.In such scenarios,the effective and efficient utilization of the liquified natural gas(LNG)regasification cold energy(RCE),in the economically and environmentally viable methods,could present a great opportunity in tackling the core issues related to global warming across the world.In this paper,the technologies that are widely used to harness the LNG RCE for electrical power have been reviewed.The systems incorporating,the Rankine cycles,Stirling engines,Kalina cycles,Brayton cycles,Allam cycles,and fuel cells have been considered.Additionally,the economic and environmental studies apart from the thermal studies have also been reviewed.Moreover,the discussion regarding the systems with respect to the regassification pressure of the LNG has also been provided.The aim of this paper is to provide guidelines for the prospective researchers and policy makers in their decision making.展开更多
Liquefied natural gas （LNG）, an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG ...Liquefied natural gas （LNG）, an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG cold energy are introduced and summarized. The direction of cycle improvement can be divided into the key factors affecting basic power generation cycles and the structural enhancement of cycles utilizing LNG cold energy. The former includes the effects of LNG-side parameters, working fluids, and inlet and outlet thermodynamic parameters of equipment, while the latter is based on Rankine cycle, Brayton cycle, Kalina cycle and their compound cycles. In the present paper, the diversities of cryogenic power generation cycles utilizing LNG cold energy are discussed and analyzed. It is pointed out that further researches should focus on the selection and component matching of organic mixed working fluids and the combination of process simulation and experi- mental investigation, etc.展开更多
文摘Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.
基金Sponsored by the Liaoning Provincial Science and Technology Program Project(Grant No.2012219024)
文摘In order to improve efficiency of a combined power system in which waste heat from exhaust gas could be efficiently recovered and cold energ^^ of liquefied natural gas （LNG） could be fully utilized as well. A system simulation and ther^nodynamic analysis were carried out, the Kalina cycle was reorganized by changing the concentration of “basic composition”, so that a better thermal matching in the heat exchanger could be obtained and the irreversibility of the system was decreased. It was found that the Kalina cycle generally used in the bottom of combined power cycle could also be used to recover the cold energy of LNG. The results show that the exergy efficiency of 42.97% is obtained. Compared with the previous system attained the exergy efficiency of 39.76%, the improved system has a better performance.
基金the National Research Foundation of Korea(NRF)funded by the Korea government(MSIT)(Grant Nos.2020R1A5A8018822 and 2021R1C1C2009287)the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry and Energy(MOTIE)of the Republic of Korea(No.20223030040120).
文摘In modern times,worldwide requirements to curb greenhouse gas emissions,and increment in energy demand due to the progress of humanity,have become a serious concern.In such scenarios,the effective and efficient utilization of the liquified natural gas(LNG)regasification cold energy(RCE),in the economically and environmentally viable methods,could present a great opportunity in tackling the core issues related to global warming across the world.In this paper,the technologies that are widely used to harness the LNG RCE for electrical power have been reviewed.The systems incorporating,the Rankine cycles,Stirling engines,Kalina cycles,Brayton cycles,Allam cycles,and fuel cells have been considered.Additionally,the economic and environmental studies apart from the thermal studies have also been reviewed.Moreover,the discussion regarding the systems with respect to the regassification pressure of the LNG has also been provided.The aim of this paper is to provide guidelines for the prospective researchers and policy makers in their decision making.
文摘Liquefied natural gas （LNG）, an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG cold energy are introduced and summarized. The direction of cycle improvement can be divided into the key factors affecting basic power generation cycles and the structural enhancement of cycles utilizing LNG cold energy. The former includes the effects of LNG-side parameters, working fluids, and inlet and outlet thermodynamic parameters of equipment, while the latter is based on Rankine cycle, Brayton cycle, Kalina cycle and their compound cycles. In the present paper, the diversities of cryogenic power generation cycles utilizing LNG cold energy are discussed and analyzed. It is pointed out that further researches should focus on the selection and component matching of organic mixed working fluids and the combination of process simulation and experi- mental investigation, etc.
