A modified Allam cycle without compressors realizing efficient power generation with peak load shifting and CO2 capture

Zhu, Zilong; Chen, Yaping; Wu, Jiafeng; Zhang, Shaobo; Zheng, Shuxing

doi:10.1016/j.energy.2019.01.165

Cited by 63 publications

(12 citation statements)

References 35 publications

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“…Further work, using the techniques in this paper, can be conducted to investigate the exergy analysis of the modified Allam Cycle (Z-cycle) proposed by Zhu et al [41] where they have utilized high pressure pumps instead of compressors. This would improve upon their findings of efficiency or help in the validation of their work.…”

Section: Conclusion and Recommendationsmentioning

confidence: 99%

Process and Carbon Footprint Analyses of the Allam Cycle Power Plant Integrated with an Air Separation Unit

Fernandes

Wang

et al. 2019

Clean Technol.

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The Allam cycle is the latest advancement in power generation technologies with a high cycle efficiency, zero NOx emission, and carbon dioxide available at pipeline specification for sequestration and utilization. The Allam cycle plant is a semi-closed, direct-fired, oxy-fuel Brayton cycle that uses high pressure supercritical carbon dioxide as a working fluid with sophisticated heat recuperation. This paper conducted process analyses including exergy analysis, sensitivity analysis, air separation unit (ASU) oxygen pump/compressor option analysis, and carbon footprint analysis for the integrated Allam power plant (natural gas)/ASU complex with a high degree of heat and work integration. Earlier works on exergy analysis were done on the Allam cycle and ASU independently. Exergy analysis on the integrated plants helps identify the equipment with the largest loss of thermodynamic efficiency. Sensitivity analysis investigated the effects of important ASU operational parameters along with equipment constraint limits on the downstream Allam cycle. Energy efficiency and carbon footprint are compared among the state-of-the-art fossil-fuel power generation cycles.

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Section: Conclusion and Recommendationsmentioning

confidence: 99%

Process and Carbon Footprint Analyses of the Allam Cycle Power Plant Integrated with an Air Separation Unit

Fernandes

Wang

et al. 2019

Clean Technol.

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“…Promising areas for further efficiency improvement of the Allam cycle are the transition to the Allam-Z cycle by the elimination of compressors [21] and integration of the additional low temperature cycles for utilization of the various low-grade heat sources.…”

Section: Parametric Optimization Of the Allam Cyclementioning

confidence: 99%

“…One of the latest modifications of the Allam cycle is the Allam-Z cycle proposed in [21]. The main modifications are that all the working media are pumped to high pressure by pumps instead of compressors, the cold energy of both liquid oxygen and liquefied natural gas is used for degrading the cooling water for carbon dioxide liquefaction, and a set of regenerative heat exchangers are arranged for turbine exhaust heat recovery.…”

Section: Introductionmentioning

confidence: 99%

Research and Development of the Oxy-Fuel Combustion Power Cycles with CO2 Recirculation

Rogalev

Kindra

et al. 2021

Energies

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The transition to oxy-fuel combustion power cycles is a prospective way to decrease carbon dioxide emissions into the atmosphere from the energy sector. To identify which technology has the highest efficiency and the lowest emission level, a thermodynamic analysis of the semiclosed oxy-fuel combustion combined cycle (SCOC-CC), the E-MATIANT cycle, and the Allam cycle was carried out. The modeling methodology has been described in detail, including the approaches to defining the working fluid properties, the mathematical models of the air separation unit, and the cooled gas turbine cycles’ calculation algorithms. The gas turbine inlet parameters were optimized using the developed modeling methodology for the three oxy-fuel combustion power cycles with CO2 recirculation in the inlet temperature at a range of 1000 to 1700 °C. The effect of the coolant flow precooling was evaluated. It was found that a decrease in the coolant temperature could lead to an increase of the net efficiency up to 3.2% for the SCOC-CC cycle and up to 0.8% for the E-MATIANT cycle. The final comparison showed that the Allam cycle’s net efficiency is 5.6% higher compared to the SCOC-CC cycle, and 11.5% higher compared with the E-MATIANT cycle.

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“…The heat loads of the heat exchangers and electric energy consumption are considered here as they close relatedly with the cost of the system. In the upper stage, the heat loads of the generator, condenser and intercooler are calculated by, , , in which the Wcom and Wpump are calculated by [38] ,, (14) in which ηcom represents the isentropic efficiency of compressor, and ηcom=0.85 [39] . Furthermore, the coefficient of performance (COP) of the system is given by In order to solve the equations mentioned-above, a flowchart is developed for the procedures.…”

Section: Thermodynamic Analysis Of Systemmentioning

confidence: 99%

Prospect of solar-driven ejector-compression hybrid refrigeration system with low GWP refrigerants in summer of Guangzhou and Beijing

Wang

Yan

et al. 2020

International Journal of Refrigeration

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In this paper, the prospect of low-GWP refrigerants used in solar-driven ejector-compression hybrid refrigeration system was analyzed and evaluated based on the solar radiation data in summer of Beijing and Guangzhou. Prominent environmental friendly alternative refrigerants, including HCFO-1233zd(E), HFO-1336mzz(Z), HFO-1234ze(Z), HCFO-1224yd(Z) and HC-600 were chosen as the working fluids to address the environmental concerns, while HFC-245fa was used as the baseline refrigerant. The hybrid refrigeration system composed of an ejector refrigeration system as the upper stage and a vapor compression system as the bottom stage, respectively. The results indicated that the system with HFO-1234ze(Z) showed the highest COP. HFO-1234ze(Z) was followed by HCFO-1233zd(E) and HC-600, and all of them showed higher COP than that of HFC-245fa. The system with HC-600 needed more electric energy than any other systems, while HFO-1336mzz(Z) consumed the lowest electric power. Meanwhile, the performances of HFO-1234ze(Z) and HFC-245fa systems were further compared. It was found that for both working fluids, the heat load of the condenser (Qe,c), total electric energy consumption (We) and electric energy of compressor (Wcom) in August were the highest in Beijing, while in Guangzhou, the highest of them was achieved in September. It was also suggested that the solar radiation had no influence on the relative magnitude of the Qe,c, We and Wcom between HFO-1234ze(Z) and HFC-245fa systems. The Qe,c, We and Wcom of the system with HFO-1234ze(Z) were higher than those of HFC-245fa by 0.8%, 4.44%, and 3.55%, respectively.

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A modified Allam cycle without compressors realizing efficient power generation with peak load shifting and CO2 capture

Cited by 63 publications

References 35 publications

Process and Carbon Footprint Analyses of the Allam Cycle Power Plant Integrated with an Air Separation Unit

Process and Carbon Footprint Analyses of the Allam Cycle Power Plant Integrated with an Air Separation Unit

Research and Development of the Oxy-Fuel Combustion Power Cycles with CO2 Recirculation

Prospect of solar-driven ejector-compression hybrid refrigeration system with low GWP refrigerants in summer of Guangzhou and Beijing

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