A Humid Air Turbine–Organic Rankine Cycle combined cycle for distributed microgeneration

2015 ◽  
Vol 104 ◽  
pp. 115-126 ◽  
Author(s):  
Ricardo Chacartegui ◽  
José A. Becerra ◽  
Maria J. Blanco ◽  
José M. Muñoz-Escalona
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Humid Air ◽  
Air Turbine

scholarly journals Humid Air Turbine Cycles With Water Recovery: How to Dispose Heat in an Efficient Way

1998 ◽  
Author(s):  
Umberto Desideri ◽  
Francesco Di Maria
Keyword(s):  
Flue Gas ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Plant Performance ◽  
Water Recovery ◽  
Humid Air ◽  
Air Turbine ◽  
Recovery System ◽  
Additional Costs ◽  
Original Configuration

Since the humid air turbine (HAT) cycle was first presented by Rao and Joiner (1990), several modifications were proposed to the original configuration to further improve its efficiency. In the last years, the attention was focused in the water recovery from flue gas and in determining the most suitable systems to separate water from gas and solving the problem of low temperature at the stack. In all the above studies it was shown that condensing water from flue gas requires a significant flow rate of a cooling medium (generally water) which is needed to remove condensation heat which must then be disposed in the environment. This worsens power plant performance because large cooling towers are needed. On the other hand, the reduced cost of water treatment may compensate the additional costs of the condensation equipment. In this paper, the introduction of an Organic Rankine Cycle (ORC), which transforms in mechanical power a fraction of the heat recovered from the HAT cycle, both in the water recovery system and in other heat exchangers, is presented. Results were obtained by using three different fluids and maximizing the ORC input exergy. The substances which were used are the conventional R502 refrigerant fluid, ammonia and the new HF134a, which is replacing phased-out CFCs in refrigeration systems.

Biomass combined cycles based on externally fired gas turbines and organic Rankine expanders

2011 ◽  
Vol 225 (8) ◽  
pp. 1066-1075 ◽  
Author(s):  
C M Invernizzi ◽  
P Iora ◽  
R Sandrini
Keyword(s):  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Economic Feasibility ◽  
Maximum Efficiency ◽  
Working Fluid ◽  
Inlet Temperature ◽  
System A ◽  
Combined Cycles

This article investigates the possibility to enhance the performance of a biomass organic Rankine cycle (ORC) plant by adding an externally fired gas turbine (EFGT), yielding a combined EFGT + ORC system. A typical ORC configuration is first modelled and validated on data available from an existing unit 1.5 MW reference plant. Then, different working fluids belonging to the methyl-substituted benzene series and linear methylpolysiloxanes have been evaluated for the ORC section on the basis of both thermodynamics considerations and design issues of the regenerator and the turbine. Results of the simulations of the combined cycle (CC) referred to a furnace size of about unit 9 MW, assuming a maximum GT inlet temperature of 800 °C, show a maximum efficiency of 23 per cent, obtained in the case where toluene is adopted as a working fluid for the bottoming section. This value is about 4 points per cent higher than the efficiency of the corresponding simple ORC. Finally, to conclude, some preliminary considerations are given regarding the techno-economic feasibility of the combined configuration, suggesting the need of a further investigation on the possible technological solution for the furnace which represents the main uncertainty in the resulting costs of the CC.

Performance Evaluation of a Small Scale High Efficiency Cogeneration System

2006 ◽  
Author(s):  
Mauro Reini
Keyword(s):  
High Efficiency ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Small Scale ◽  
Performance Parameters ◽  
Cogeneration System

In recent years, a big effort has been made to improve microturbines thermal efficiency, in order to approach 40%. Two main options may be considered: i) a wide usage of advanced materials for hot ends components, like impeller and recuperator; ii) implementing more complicated thermodynamic cycle, like combined cycle. In the frame of the second option, the paper deals with the hypothesis of bottoming a low pressure ratio, recuperated gas cycle, typically realized in actual microturbines, with an Organic Rankine Cycle (ORC). The object is to evaluate the expected nominal performance parameters of the integrated-combined cycle cogeneration system, taking account of different options for working fluid, vapor pressure and component’s performance parameters. Both options of recuperated and not recuperated bottom cycles are discussed, in relation with ORC working fluid nature and possible stack temperature for microturbine exhaust gases. Finally, some preliminary consideration about the arrangement of the combined cycle unit, and the effects of possible future progress of gas cycle microturbines are presented.

scholarly journals Thermodynamic Investigation of an Integrated Solar Combined Cycle with an ORC System

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 428 ◽  
Author(s):  
Wang ◽  
Fu
Keyword(s):  
Solar Radiation ◽  
Thermal Efficiency ◽  
Unit Cost ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Exhaust Gas Temperature

An integrated solar combined cycle (ISCC) with a low temperature waste heat recovery system is proposed in this paper. The combined system consists of a conventional natural gas combined cycle, organic Rankine cycle and solar fields. The performance of an organic Rankine cycle subsystem as well as the overall proposed ISCC system are analyzed using organic working fluids. Besides, parameters including the pump discharge pressure, exhaust gas temperature, thermal and exergy efficiencies, unit cost of exergy for product and annual CO2-savings were considered. Results indicate that Rc318 contributes the highest exhaust gas temperature of 71.2℃, while R113 showed the lowest exhaust gas temperature of 65.89 at 800 W/m2, in the proposed ISCC system. The overall plant thermal efficiency increases rapidly with solar radiation, while the exergy efficiency appears to have a downward trend. R227ea had both the largest thermal efficiency of 58.33% and exergy efficiency of 48.09% at 800W/m2. In addition, for the organic Rankine cycle, the exergy destructions of the evaporator, turbine and condenser decreased with increasing solar radiation. The evaporator contributed the largest exergy destruction followed by the turbine, condenser and pump. Besides, according to the economic analysis, R227ea had the lowest production cost of 19.3 $/GJ.

Efficiency Improvement of Natural Gas Combined Cycle Power Plant With CO2 Capturing and Sequestration

2012 ◽  
Author(s):  
Abdullah Al-Abdulkarem ◽  
Yunho Hwang ◽  
Reinhard Radermacher
Keyword(s):  
Natural Gas ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Simulation Software ◽  
Combined Cycle ◽  
Co2 Removal ◽  
Efficiency Improvement ◽  
Absorption Chillers ◽  
Natural Gas Combined Cycle

Although natural gas is considered as a clean fuel compared to coal, natural gas combined cycles (NGCC) emit high amounts of CO2 at the plant site. To mitigate global warming caused by the increase in atmospheric CO2, CO2 capture and sequestration (CCS) using amine absorption is proposed. However, implementing this CCS system increases the energy consumption by about 15–20%. Innovative processes integration and waste heat utilization can be used to improve the energy efficiency. Four waste heat sources and five potential uses were uncovered and compared using a parameter defined as the ratio of power gain to waste heat. A new integrated CCS configuration is proposed, which integrates the NGCC with the CO2 removal and CO2 compression cycles. HYSYS simulation software was used to simulate the CO2 removal cycle using monoethanolamine (MEA) solution, NGCC, CO2 compression cycle, CO2 liquefaction cycles and Organic Rankine Cycle (ORC). The developed models were validated against experimental data from the literature with good agreements. Two NGCC with steam extraction configurations were optimized using Matlab GA tool coupled with HYSYS simulation software. Efficiency improvement in one of the proposed CCS configurations that uses the available waste heat in absorption chillers to cool the inlet-air to the gas turbine and to run an ORC, and uses the developed CO2 liquefaction and pumping instead of multistage compression is 6.04 percent point, which represents 25.91 MW more power than the conventional CCS configuration.

Research on the Combined Cycle of a Biogas Micro Gas Turbine and an Organic Rankine Cycle

2019 ◽  
Vol 13 (5) ◽  
pp. 683-689
Author(s):  
Zheng Jian ◽  
Feng Zheng-Jiang ◽  
Wang Jian ◽  
Wang Yan ◽  
Li Xin-Yi ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Micro Gas Turbine

scholarly journals Technologies for Waste Heat Recovery in Off-Shore Applications

2013 ◽  
Author(s):  
Leonardo Pierobon ◽  
Fredrik Haglind ◽  
Rambabu Kandepu ◽  
Alessandro Fermi ◽  
Nicola Rossetti
Keyword(s):  
Thermal Efficiency ◽  
Heat Recovery ◽  
Net Present Value ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Present Value ◽  
Payback Time ◽  
Low Weight

In off-shore oil and gas platforms the selection of the gas turbine to support the electrical and mechanical demand on site is often a compromise between reliability, efficiency, compactness, low weight and fuel flexibility. Therefore, recovering the waste heat in off-shore platforms presents both technological and economic challenges that need to be overcome. However, onshore established technologies such as the steam Rankine cycle, the air bottoming cycle and the organic Rankine cycle can be tailored to recover the exhaust heat off-shore. In the present paper, benefits and challenges of these three different technologies are presented, considering the Draugen platform in the North Sea as a base case. The Turboden 65-HRS unit is considered as representative of the organic Rankine cycle technology. Air bottoming cycles are analyzed and optimal design pressure ratios are selected. We also study a one pressure level steam Rankine cycle employing the once-through heat recovery steam generator without bypass stack. We compare the three technologies considering the combined cycle thermal efficiency, the weight, the net present value, the profitability index and payback time. Both incomes related to CO2 taxes and natural gas savings are considered. The results indicate that the Turboden 65-HRS unit is the optimal technology, resulting in a combined cycle thermal efficiency of 41.5% and a net present value of around 15 M$, corresponding to a payback time of approximately 4.5 years. The total weight of the unit is expected to be around 250 ton. The air bottoming cycle without intercooling is also a possible alternative due to its low weight (76 ton) and low investment cost (8.8 M$). However, cycle performance and profitability index are poorer, 12.1% and 0.75. Furthermore, the results suggest that the once-trough single pressure steam cycle has a combined cycle thermal efficiency of 40.8% and net present value of 13.5 M$. The total weight of the steam Rankine cycle is estimated to be around 170 ton.

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