Integration and Optimization of the Gas Removal System for Hybrid-Cycle OTEC Power Plants

1990 ◽  
Vol 112 (1) ◽  
pp. 19-28 ◽  
Author(s):  
T. J. Rabas ◽  
C. B. Panchal ◽  
H. C. Stevens
Keyword(s):  
Power Plants ◽  
Gas Flow ◽  
High Efficiency ◽  
Preliminary Design ◽  
Gas Removal ◽  
Practical Design ◽  
Previous Design ◽  
Specific Number ◽  
Removal System ◽  
Hybrid Cycle

A preliminary design of the noncondensible gas removal system for a 10 MWe, land-based hybrid-cycle OTEC power plant has been developed and is presented herein. This gas removal system is very different from that used for conventional power plants because of the substantially larger and continuous noncondensible gas flow rates and lower condenser pressure levels which predicate the need for higher-efficiency components. Previous OTEC studies discussed the need for multiple high-efficiency compressors with intercoolers; however, no previous design effort was devoted to (a) the details of the intercoolers, (b) integration and optimization of the intercoolers with the compressors, and (c) the practical design constraints and feasibility issues of these components. The resulting gas removal system design uses centrifugal (radial) compressors with matrix-type crossflow aluminum heat exchangers as intercoolers. Once-through boiling of ammonia is used as the heat sink for the cooling and condensing of the steam-gas mixture. A computerized calculation method was developed for the performance analysis and subsystem optimization. For a specific number of compressor units and the stream arrangement, the method is used to calculate the dimensions, speeds, power requirements, and costs of all the components.

SOFC-Based Hybrid Cycle Integrated With a Coal Gasification Plant

2009 ◽  
Author(s):  
Matteo C. Romano ◽  
Stefano Campanari ◽  
Vincenzo Spallina ◽  
Giovanni Lozza
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Power Plants ◽  
Large Scale ◽  
Coal Gasification ◽  
High Efficiency ◽  
Thermal Power ◽  
Operating Pressure ◽  
Efficiency Gain ◽  
Hybrid Cycle

Application of large scale high temperature fuel cells on syngas fuel produced from coal would be a turning point in the power generation sector, dramatically improving the efficiency and the environmental performance of coal-fired power plants. The purpose of this study is the assessment of a system constituted by a SOFC-based hybrid cycle integrated with a coal gasification process. In this system, syngas produced in a high efficiency, dry feed, oxygen blown, entrained flow Shell gasifier is cooled, depurated from particulate and sulfur compounds and reheated; the clean syngas feeds a pressurized SOFC together with high pressure air generated by the compressor of a gas turbine. After combustion of unconverted syngas, fuel cell exhausts are expanded and cooled, providing heat to a bottoming steam cycle for an efficient energy recovery. A high integration between gasification and power islands is necessary in order to obtain an elevated efficiency: the heat recovery system from syngas cooling is carefully arranged to provide thermal power for clean syngas reheating, air preheating and steam generation. The paper presents a preliminary analysis of literature results and a discussion of the thermodynamic implications arising from the use of different primary fuels in a fuel cell-gas turbine cycle. Then the work presents a detailed thermodynamic analysis of the proposed IGFC layout, assessing the effect of SOFC operating pressure on power balance and net plant efficiency. A sensitivity analysis on the variation of fuel and air utilization in the fuel cell is also performed. Results show that the present innovative SOFC-based power system may achieve an efficiency gain of 7–11 percentage points, with respect to an advanced IGCC based on state of the art technology.

scholarly journals Primary System Design Studies for Advanced Direct Cycle Nuclear Gas Turbine Plant

1977 ◽  
Author(s):  
Colin F. McDonald ◽  
John C. Bass ◽  
Hans H. Amtmann
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Gas Flow ◽  
Economic Incentives ◽  
Inlet Temperature ◽  
Primary System ◽  
Preliminary Design ◽  
Reactor Outlet ◽  
Helium Gas ◽  
Direct Cycle

Continuing studies of the Gas Turbine High Temperature Gas Cooled Reactor (GT-HTGR) power plant have been directed toward identification of a plant configuration with improved economic incentives over competing electric power plants. This paper outlines the studies which led to the selection of the primary system for a plant with optimized parameters from the standpoint of minimum power generating cost. As in previously reported designs, an integrated type of plant embodying multiple helium gas turbine loops was selected. The layout of the power conversion loop (PCL) components in the prestressed concrete reactor vessel (PCRV) and the development of the primary system helium gas flow paths are discussed. The studies reported in this paper led to changes in the PCRV geometry which had a significant impact by reduction in the size of the PCRV and attendant cost savings. With orientation and configuration of the major PCL components forming the basis of these studies, some of the preliminary design considerations for the turbomachinery, heat exchangers, thermal barrier and control valves together with maintenance considerations are discussed. The reference plant preliminary design presented is based on a 3000 MW(t) core thermal rating with a reactor outlet (turbine inlet) temperature of 850 C: the overall plant efficiency of the dry-cooled direct cycle nuclear gas turbine is 40 percent.

"Recent Patents on the Triboelectrostatic Separation of Fly Ash"

2019 ◽  
Vol 13 ◽  
Author(s):  
Haisheng Li ◽  
Wenping Wang ◽  
Yinghua Chen ◽  
Xinxi Zhang ◽  
Chaoyong Li
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
High Efficiency ◽  
Separation Efficiency ◽  
High Reliability ◽  
Operating Conditions ◽  
Security Requirements ◽  
Unburned Carbon ◽  
Efficient Operation ◽  
Triboelectrostatic Separation

Background: The fly ash produced by coal-fired power plants is an industrial waste. The environmental pollution problems caused by fly ash have been widely of public environmental concern. As a waste of recoverable resources, it can be used in the field of building materials, agricultural fertilizers, environmental materials, new materials, etc. Unburned carbon content in fly ash has an influence on the performance of resource reuse products. Therefore, it is the key to remove unburned carbon from fly ash. As a physical method, triboelectrostatic separation technology has been widely used because of obvious advantages, such as high-efficiency, simple process, high reliability, without water resources consumption and secondary pollution. Objective: The related patents of fly ash triboelectrostatic separation had been reviewed. The structural characteristics and working principle of these patents are analyzed in detail. The results can provide some meaningful references for the improvement of separation efficiency and optimal design. Methods: Based on the comparative analysis for the latest patents related to fly ash triboelectrostatic separation, the future development is presented. Results: The patents focused on the charging efficiency and separation efficiency. Studies show that remarkable improvements have been achieved for the fly ash triboelectrostatic separation. Some patents have been used in industrial production. Conclusion: According to the current technology status, the researches related to process optimization and anti-interference ability will be beneficial to overcome the influence of operating conditions and complex environment, and meet system security requirements. The intelligent control can not only ensure the process continuity and stability, but also realize the efficient operation and management automatically. Meanwhile, the researchers should pay more attention to the resource utilization of fly ash processed by triboelectrostatic separation.

scholarly journals Effect of Flue Gases’ Corrosive Components on the Degradation Process of Evaporator Tubes

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3860
Author(s):  
Mária Hagarová ◽  
Milan Vaško ◽  
Miroslav Pástor ◽  
Gabriela Baranová ◽  
Miloš Matvija
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Gas Flow ◽  
Degradation Process ◽  
Flue Gases ◽  
Saturated Steam ◽  
Mineral Salts ◽  
Related Factors ◽  
Local Overheating ◽  
Inner Surface

Corrosion of boiler tubes remains an operational and economic limitation in municipal waste power plants. The understanding of the nature, mechanism, and related factors can help reduce the degradation process caused by corrosion. The chlorine content in the fuel has a significant effect on the production of gaseous components (e.g., HCl) and condensed phases on the chloride base. This study aimed to analyze the effects of flue gases on the outer surface and saturated steam on the inner surface of the evaporator tube. The influence of gaseous chlorides and sulfates or their deposits on the course and intensity of corrosion was observed. The salt melts reacted with the steel surface facing the flue gas flow and increased the thickness of the oxide layer up to a maximum of 30 mm. On the surface not facing the flue gas flow, they disrupted the corrosive layer, reduced its adhesion, and exposed the metal surface. Beneath the massive deposits, a local overheating of the inner surface of the evaporator tubes occurred, which resulted in the release of the protective magnetite layer from the surface. Ash deposits reduce the boiler’s thermal efficiency because they act as a thermal resistor for heat transfer between the flue gases and the working medium in the pipes. The effect of insufficient feedwater treatment was evinced in the presence of mineral salts in the corrosion layer on the inner surface of the tube.

Performance and Water Consumption of the Solar Steam-Injection Gas Turbine Cycle

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Maya Livshits ◽  
Abraham Kribus
Keyword(s):  
Gas Turbine ◽  
Water Consumption ◽  
Power Plants ◽  
Solar Power ◽  
Low Cost ◽  
Steam Injection ◽  
Water Recovery ◽  
Solar Power Plants ◽  
Improved Model ◽  
Hybrid Cycle

Solar heat at moderate temperatures around 200 °C can be utilized for augmentation of conventional steam-injection gas turbine power plants. Solar concentrating collectors for such an application can be simpler and less expensive than collectors used for current solar power plants. We perform a thermodynamic analysis of this hybrid cycle, focusing on improved modeling of the combustor and the water recovery condenser. The cycle's water consumption is derived and compared to other power plant technologies. The analysis shows that the performance of the hybrid cycle under the improved model is similar to the results of the previous simplified analysis. The water consumption of the cycle is negative due to water production by combustion, in contrast to other solar power plants that have positive water consumption. The size of the needed condenser is large, and a very low-cost condenser technology is required to make water recovery in the solar STIG cycle technically and economically feasible.

Effect Of Equivalent Ratio (ER) On the Flow and Combustion Characteristics in A Typical Underground Coal Gasification (UCG) Cavity

2021 ◽  
Vol 86 (2) ◽  
pp. 28-38
Author(s):  
Arup Kumar Biswas ◽  
Wasu Suksuwan ◽  
Khamphe Phoungthong ◽  
Makatar Wae-hayee
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Coal Gasification ◽  
High Efficiency ◽  
Combustion Characteristics ◽  
Raw Material ◽  
Underground Coal Gasification ◽  
Equivalent Ratio ◽  
Rubble Pile

Underground Coal Gasification (UCG) is thought to be the most favourable clean coal technology option from geological-engineering-environmental viewpoint (less polluting and high efficiency) for extracting energy from coal without digging it out or burning it on the surface. UCG process requires only injecting oxidizing agent (O2 or air with steam) as raw material, into the buried coal seam, at an effective ratio which regulates the performance of gasification. This study aims to evaluate the influence of equivalent ratio (ER) on the flow and combustion characteristics in a typical half tear-drop shape of UCG cavity which is generally formed during the UCG process. A flow modeling software, Ansys FLUENT is used to construct a 3-D model and to solve problems in the cavity. The boundary conditions are- (i) a mass-flow-inlet passing oxidizer (in this case, air) into the cavity, (ii) a fuel-inlet where the coal volatiles are originated and (iii) a pressure-outlet for flowing the product Syngas out of the cavity. A steady-state simulation has been run using k-? turbulence model. The mass flow rate of air varied according to an equivalent ratio (ER) of 0.16, 0.33, 0.49 and 0.82, while the fuel flow rate was fixed. The optimal condition of ER has been identified through observing flow and combustion characteristics, which looked apparently stable at ER 0.33. In general, the flow circulation mainly takes place around the ash-rubble pile. A high temperature zone is found at the air-releasing point of the injection pipe into the ash-rubble pile. This study could practically be useful to identify one of the vital controlling factors of gasification performance (i.e., ER impact on product gas flow characteristics) which might become a cost-effective solution in advance of commencement of any physical operation.

FEATURES OF THE METHODOLOGY OF THERMODYNAMIC MODELING OF GAS TURBINE AND COMBINED ON THEIR BASIS POWER PLANTS

2017 ◽  
Author(s):  
Gennadii Liubchik ◽  
◽  
Nataliia Fialko ◽  
Aboubakr Regragui ◽  
Julii Sherenkovskii ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Thermodynamic Modeling ◽  
Power Plants ◽  
High Efficiency ◽  
Technical Facility

The article presents the enthalpy-entropy methodology of thermodynamic analysis of gas turbine and combined power plants on their basis, the results of testing the method on a real technical facility, proving its high efficiency.

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