Trigeneration: Thermodynamic Performance and Cold Expander Aerodynamic Design in Humid Air Turbines

Author(s):  
Magnus Genrup ◽  
Marcus Thern ◽  
Mohsen Assadi

Improving electrical efficiency has been proposed as the most convenient means of reducing, e.g. CO2 emission from power plants. Increasing fuel utilization through combined heat and power generation is another useful measure for emission reduction. Trigeneration technology for the production of heat, power and cooling is an interesting alternative for further improvement of fuel utilization. Previous studies at The Department of Heat and Power Engineering in Lund, Sweden, have shown that wet cycles are the best candidates, with a high potential to achieve fuel utilization higher than 100%, based on the fuel’s lower heating value [1, 2, 8]. Apart from high fuel utilization, trigeneration technology can produce cooling without the use of harmful cooling agents. The basic principle of trigeneration is to interrupt the expansion at an elevated pressure level and extract heat from the working medium. The final expansion then takes place at low temperature admission levels resulting in a very low temperature at the turbine exhaust. In this paper results from both thermodynamic analysis of the humid air turbine concept in conjunction with trigeneration, and the expander design criterion required for realization of the last section of the expander are presented. The thermodynamic study gives the boundary conditions for the cold turbine design. Optimum conditions for the inlet to the cold expander are a pressure of 2 to 3 bar and a temperature of 47°C. This may put serious loading constraints on the final cold expander design due to Mach and Reynolds number effects. This problem has been investigated and a detailed study of the aerodynamic loading and efficiency levels achievable is presented, using a mid-span and SCM-throughflow approach. This paper will address the cycle performance and the cold turbine aerodynamic limitations on the thermodynamic optima.

2020 ◽  
Vol 12 (4) ◽  
pp. 281-285
Author(s):  
A. V. Martynov ◽  
N. E. Kutko

The article deals with the problem of waste disposal and, accordingly, landfills in the Moscow Region, which have now become the number 1 problem for the environment in Moscow and the Moscow Region. To solve this problem, incineration plants (IP) will be established in the near future. 4 plants will be located in the Moscow Region that will be able to eliminate 2800 thousand tons of waste per year. Burning of waste results in formation of slag making 25% of its volume, which has a very high temperature (1300.1500°C). An arrangement is considered, in which slag is sent to a water bath and heats the water to 50.90°C. This temperature is sufficient to evaporate any low-temperature substance (freons, limiting hydrocarbons, etc.), whereupon the steam of the low-temperature working medium is sent to a turbine, which produces additional electricity. The creation of a low-temperature thermal power plant (TPP) increases the reliability of electricity generation at the IP. The operation of low-temperature TPPs due to the heat of slag is very efficient, their efficiency factor being as high as 40.60%. In addition to the efficiency of TPPs, capital costs for the creation of additional devices at the IP are of great importance. Thermal power plants operating on slag are just such additional devices, so it is necessary to minimize the capital costs of their creation. In addition to equipment for the operation of TPPs, it is necessary to have a working medium in an amount determined by calculations. From the wide variety of working media, which are considered in the article, it is necessary to choose the substance with the lowest cost.


Author(s):  
Andrea Corti ◽  
Bruno Facchini ◽  
Giampaolo Manfrida ◽  
Umberto Desideri

A comparison between power plants built according to the HAT (Humid Air Turbine) and SCGT/CC (Semi-Closed Gas Turbine/Combined Cycle) concepts is presented, ranging from thermodynamic performance (efficiency and specific power output) to projected data for plant construction and operating costs. Both options appear to be of potential interest to electric utilities considering advanced gas turbine power plants, with significant differences form the point of view of plant size, water consumption, and adaptability to advanced developments for the limitation of environmental impact (CO2 emissions).


Author(s):  
Shane E. Powers ◽  
William C. Wood

With the renewed interest in the construction of coal-fired power plants in the United States, there has also been an increased interest in the methodology used to calculate/determine the overall performance of a coal fired power plant. This methodology is detailed in the ASME PTC 46 (1996) Code, which provides an excellent framework for determining the power output and heat rate of coal fired power plants. Unfortunately, the power industry has been slow to adopt this methodology, in part because of the lack of some details in the Code regarding the planning needed to design a performance test program for the determination of coal fired power plant performance. This paper will expand on the ASME PTC 46 (1996) Code by discussing key concepts that need to be addressed when planning an overall plant performance test of a coal fired power plant. The most difficult aspect of calculating coal fired power plant performance is integrating the calculation of boiler performance with the calculation of turbine cycle performance and other balance of plant aspects. If proper planning of the performance test is not performed, the integration of boiler and turbine data will result in a test result that does not accurately reflect the true performance of the overall plant. This planning must start very early in the development of the test program, and be implemented in all stages of the test program design. This paper will address the necessary planning of the test program, including: • Determination of Actual Plant Performance. • Selection of a Test Goal. • Development of the Basic Correction Algorithm. • Designing a Plant Model. • Development of Correction Curves. • Operation of the Power Plant during the Test. All nomenclature in this paper utilizes the ASME PTC 46 definitions for the calculation and correction of plant performance.


2015 ◽  
Vol 5 (2) ◽  
pp. 89
Author(s):  
Munzer S. Y. Ebaid ◽  
Qusai Z. Al-hamdan

<p class="1Body">Several modifications have been made to the simple gas turbine cycle in order to increase its thermal efficiency but within the thermal and mechanical stress constrain, the efficiency still ranges between 38 and 42%. The concept of using combined cycle power or CPP plant would be more attractive in hot countries than the combined heat and power or CHP plant. The current work deals with the performance of different configurations of the gas turbine engine operating as a part of the combined cycle power plant. The results showed that the maximum CPP cycle efficiency would be at a point for which the gas turbine cycle would have neither its maximum efficiency nor its maximum specific work output. It has been shown that supplementary heating or gas turbine reheating would decrease the CPP cycle efficiency; hence, it could only be justified at low gas turbine inlet temperatures. Also it has been shown that although gas turbine intercooling would enhance the performance of the gas turbine cycle, it would have only a slight effect on the CPP cycle performance.</p>


Author(s):  
Bruce A. Young ◽  
Sang-Min Lee ◽  
Paul M. Scott

As a means of demonstrating compliance with the United States Code of Federal Regulations 10CFR50 Appendix A, General Design Criterion 4 (GDC-4) requirement that primary piping systems for nuclear power plants exhibit an extremely low probability of rupture, probabilistic fracture mechanics (PFM) software has become increasingly popular. One of these PFM codes for nuclear piping is Pro-LOCA which has been under development over the last decade. Currently, Pro-LOCA is being enhanced under an international cooperative program entitled PARTRIDGE-II (Probabilistic Analysis as a Regulatory Tool for Risk-Informed Decision GuidancE - Phase II). This paper focuses on the use of a pre-defined set of base-case inputs along with prescribed variation in some of those inputs to determine a comparative set of sensitivity analyses results. The benchmarking case was a circumferential Primary Water Stress Corrosion Crack (PWSCC) in a typical PWR primary piping system. The effects of normal operating loads, temperature, leak detection, inspection frequency and quality, and mitigation strategies on the rupture probability were studied. The results of this study will be compared to the results of other PFM codes using the same base-case and variations in inputs. This study was conducted using Pro-LOCA version 4.1.9.


Author(s):  
A. Agazzani ◽  
A. F. Massardo ◽  
T. Korakianitis

This paper presents optimized cycle performance that can be obtained with systems including a Closed Cycle Gas Turbine (CCGT). The influence of maximum temperature, minimum temperature and recuperator effectiveness on cycle performance is illustrated. Several power-plant arrangements are analyzed and compared based on: thermodynamic performance (thermal efficiency and specific work); enabling technologies (available at present); and developing technologies (available in the near term or future). The work includes the effects of utilization of high temperature ceramic heat exchangers and of coupling of CCGT systems with plants vaporizing Liquid Hydrogen (LH2) or Liquefied Natural Gas (LNG). Given the versatility of energy addition and rejection sources that can be utilized in closed gas-cycle systems, the thermodynamic performance of power plants shown in this paper indicate the remarkable capabilities and possibilities for closed gas-cycle systems.


Author(s):  
Helmer Andersen

Fuel is by far the largest expenditure for energy production for most power plants. New tools for on-line performance monitoring have been developed for reducing fuel consumption while at the same time optimizing operational performance. This paper highlights a case study where an online performance-monitoring tool was employed to continually evaluate plant performance at the Kalaeloa Combined Cycle Power Plant. Justification for investment in performance monitoring tools is presented. Additionally the influence of various loss parameters on the cycle performance is analyzed with examples. Thus, demonstrating the potential savings achieved by identifying and correcting the losses typically occurring from deficiencies in high impact component performance.


2018 ◽  
Vol 53 ◽  
pp. 04005 ◽  
Author(s):  
Ding Yang ◽  
Yi Luo ◽  
XingLian Ye ◽  
WeiXiang Chen ◽  
Jun Guo ◽  
...  

SO3 is one of the main precursors of atmospheric PM2.5, and its emission has attracted more and more attention in the industry. This paper briefly analyzes the harm of SO3 and the method of controlled condensation to test SO3. The effect of cooperative removal of SO3 by ultra-low emission technology in some coal-fired power plants has been tested by using the method of controlled condensation. The results show that the cooperative removal of SO3 by ultra-low emission technology in coal-fired power plants is effective. The removal rate of SO3 by low-low temperature electrostatic precipitators and electrostatic-fabric integrated precipitators can be exceeded 80%, while the removal rate of SO3 by wet flue gas desulfurization equipment displays lower than the above two facilities, and the wet electrostatic precipitator shows a better removal effect on SO3. With the use of ultra-low emission technology in coal-fired power plants, the SO3 emission concentration of the tail chimney reaches less than 1 mg / Nm3.


2021 ◽  
pp. 83-90
Author(s):  
Alyona Shilova ◽  
◽  
Nikolay Bachev ◽  
Roman Bulbovich ◽  
◽  
...  

For a stable position of the flame front in the combustion chambers of gas turbine power plants, the fresh gas-air mixture must be heated to the ignition temperature during the entire operation process. With air excess coefficients in the interval between the upper and lower concentration limits, reverse currents from the zone of developed combustion successfully cope with this task. When organizing low-temperature combustion near the lean limit, the contribution of reverse currents to heating the fresh gas-air mixture turns out to be insufficient and additional external heating of the components in special heaters with exhaust gases from the turbine is required. The temperature characteristics of the fresh gas-air mixture at the inlet to the chamber and in the zone of return currents, as well as combustion products in the developed flame zone, were obtained from the solution of the energy balance equations. The modes of low-temperature lean combustion with excess air coefficients exceeding the lower concentration limit α = 2 are considered. The calculations were carried out for two values of the ejection coefficient in the zone of reverse currents K = 0.14 and K = 0.30. A K value of 0.14 was obtained using empirical relationships. The value K = 0.30 was obtained from the condition that during stoichiometric combustion, the gas-air mixture is heated completely by reverse currents. It is shown that with an increase in the excess air ratio to ensure a stable position of the flame front, the role of external heating of components increases.


2018 ◽  
Vol 7 (2.12) ◽  
pp. 151
Author(s):  
Gee Soo Lee ◽  
Moo Yeon Lee ◽  
Ki Hyun Kim ◽  
Chan Jung Kim

Background/Objectives: This paper focused on the simplified design of passive mount modulein electric power plants using only spring and damper elements.Methods/Statistical analysis: The selection of elements in a proposed simplified passive mount module was proceeded under the requirement, which is to show the response level same or less as compare to the case of current mount module. The response at the upper location of mount affect to negative effect on the responsible electric power plants so the design criterion should be satisfied with the newly proposed simple mount module.Findings: The frequency response function between the force and response acceleration at upper position of mount module was calculated from the theoretical mount module and the transmissibility function, between two response accelerations at two different passive mount modules, was evaluated for interesting harmonic frequencies (from 1X to 4X). The primary interesting frequency(X)was determined at 30(Hz) since the operation condition of the combustion engine in electric power plant is scheduled to be operated at constant 1,800(rev/min). Several simulation cases can be obtained for different combination of selected dampingcoefficients at the proposed mount module. The magnitude of transmissibility function should be less than one all interesting frequencies and the reasonable condition of the simple mount module can be derived from the simulation result.Then, the validation of the designed simplified mount module was conducted by preparing two kinds of mount module and the acceleration responses were measured at 1,800(rev/min) operation under 100% electric load. The spectral response at interesting frequencies confirms the superiority of the newly proposed mount module.Improvements/Applications: The simplified structure of mount module can be possible to save installation cost and time simultaneously and it is easy to conduct the maintenance of mount module.  


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