Performance Analysis of Extraction Condensing Turbine - Unit 1 at Pltu X, Bekasi, West Java

Boilers are one of the main equipment in the PLTU apart from turbines and generators. Each year there must be a difference in the actual boiler efficiency value with the conditions during commissioning. Periodically, boiler performance evaluations are carried out in order to identify losses from several factors. In this study, the method used for evaluation is the energy balance method. During the experiment, the standard test guide (ASME PTC - 4) was used. The boiler under test has a capacity of 660 MW. Evaluation is done by comparing the boiler efficiency value at the time of commissioning with the latest performance tests. From the results of performance testing, it is known that the decrease in boiler efficiency when compared with the commissioning results from 86.92% to 82.625%. The reduction in boiler efficiency is due to an increase in heat loss due to dry gas, hydrogen content in coal, and incomplete combustion.Keywords: boiler, efficiency, evaluation, reduction, performance

Relevance. Saving natural gas, reducing heat and steam emissions into the environment through deep utilization of heat from exhaust gases in a waste heat boiler and heat and moisture in a condensation waste heat boiler. Aim. Development of a combined gas-steam plant scheme and its calculation methods. Objects. Combined gas-steam plant with the introduction of water vapor into the combustion chamber of a gas turbine and deep heat recovery in a waste heat boiler and a condensing heat and moisture recovery unit from the exhaust gases. Methods. Numerical methods based on material and energy balances of systems and elements of gas-steam plants. Results. The authors have developed the thermal scheme of a combined gas-steam plant with water vapor introduction into the combustion chamber of a gas turbine and deep heat recovery in a waste heat boiler and heat and moisture from exhaust gases in a condensing waste heat boiler. Rhey developed as well the algorithm for calculating this scheme. Based on this scheme the authors written the calculation program in the EXCEL spreadsheet package using the Coolprop database of functions for calculating thermodynamic and thermal physical parameters of substances. This program allows calculating indicators with changes in the outside air parameters, the fuel burned composition, the air compression degree in the compressor, the flow rate of steam introduced into the combustion chamber, the temperature of combustion products at the inlet of the gas turbine, the electrical load on the gas turbine generator, and the exhaust gases temperature at the outlet of the heat recovery unit. The paper introduces the example of the circuit calculation for one variant of the initial data. This example showed that with the given initial data, when using the heat leaving in the waste heat boiler and condensing heat recovery unit in additional Rankine cycles, it is possible to obtain, relative to the electric power of the gas turbine of 100 MW, an increase in power of 12.34 MW: of which 8.94 MW in the steam turbine and 3.40 MW in the turbine on a low-boiling working fluid. The electrical efficiency of the combined gas-steam plant was 57.68%: while the efficiency of the gas turbine was 51.35%, the efficiency of the steam turbine was 83.48% and the efficiency of the turbine on a low-boiling working fluid was 4.86%.

Performance analysis of low speed axial impulse turbine using two type nozzles for small-scale organic Rankine cycle

The American Society of Mechanical Engineers (ASME) Performance Test Codes (PTCs) have provided the power industry with the premier source of guidance for conducting and reporting performance tests of their evolving base technologies of power producing plants and supporting components. With an overwhelming push for renewable energy in recent years, ASME PTCs are in the development of similar standards for the testing of concentrating solar thermal technologies based power plants by the formation of a committee to develop “PTC 52, Performance Test Code on Concentrated Solar Plants”, on July 2009. The U.S. Department of Energy’s (DOE) SunShot Initiative goal is to reduce costs and eliminate market barriers to make large-scale solar energy systems cost-competitive with other forms of energy by the end of the decade. The ASME PTC-52 similarly removes critical barriers hindering deployment and speeds the implementation of concentrating solar power technologies by reducing commercial risk by facilitating performance testing procedures with quantified uncertainty. As with any commercialization of power producing technologies, clearly defining risk and providing methods to mitigate those risks are essential in providing the confidence necessary to secure investment funding. The traditional power market accomplishes this by citation of codes and standards in contracts; specifically ASME PTCs which supply commercially accepted guidelines and technical standards for performance testing to validate the guarantees of the project (Power Output, Heat Rate, Efficiency, etc.). Thus providing the parties to a power project with the tools they need to ensure that the planned project performance was met and the proper transfer of funds are accomplished. To enable solar energy systems to be fully embraced by the power industry, they must have similar codes and standards to mitigate commercial risks associated with contractual acceptance testing. The ASME PTC 52 will provide these standard testing methods to validate Concentrating Solar Power (CSP) systems performance guarantees with confidence. This paper will present the affect that solar resource variability and measurement accuracies have on concentrating solar field performance uncertainty based on calculation methods like those used for conventional fossil power plants. Measurement practices and methods will be discussed to mitigate that uncertainty. These uncertainty values will be correlated to the levelized cost of electricity (LCOE), and LCOE sensitivities will be derived. The results quantify the impact of resource variability during testing, test duration and sampling rate to annual performance calculation. These uncertainties will be further associated with costs and risks based on typical technology performance guarantees. The paper will also discuss how the development of standard measurements and calculation methods help to produce lower uncertainty associated with the overall plant result, which is already being accomplished by ASME PTCs in conventional power genreation.

In the turbine governor valve (GV) operating system there are two modes, that is single mode and sequence mode. Single mode is GV operation with the same % valve opening between numbers one until four, while sequence mode is GV operation that varies between numbers one until four. In August 2020, the GV turbine unit 1 changed the operating mode, which previously used single mode since commissioning in 2014 and changed it to sequence mode. In this mode change, look for differences in values, especially on the efficiency of the high pressure (HP) turbine. The aim is to find out whether this change in operating mode has an impact on the performance of the unit 1 steam power plant. The data collected in this process are steam operating parameters which are used to calculate HP turbine efficiency with single mode and HP turbine efficiency with sequence mode. For data accuracy, these parameters are taken from DCS with the same load of 196 MW, the same coal source and calorific value. The method used to calculate the efficiency of the HP turbine is to use the first law of thermodynamics which is in accordance with the standard EPRI Heat Rate Improvement Reference Manual TR-109546. At a load of 196 MW, the efficiency of the HP turbine with single mode operating mode is 79.96%, and with sequence mode operating mode is 82.55%. From the change in operating mode, there is an increase in the efficiency of the HP turbine so that the performance of the generator is increasing.KeywordsGovernor valveHigh pressure turbineEfficiencySingle modeSequence mode

This study aims to determine the performance of steam turbine PT. PJB UBJOM PLTU Pulang Pisau Kalimantan Tengah the results of data obtained during each performance test in commisioning 2016 and 2018. This research data is taken from the control room of PT. PJB UBJOM PLTU Pulang Pisau, variable data obtained in the form of load, main inlet steam temperature, main inlet steam pressure, HP heater feed outlet temperature, HP heater feed outlet pressure, main steam flow, and turbine by pass flow. The data is processed to get the turbine heat rate and the efficiency per time of each performance test and then averaging the data results over time, then comparing the turbine heat rate and the average efficiency of each performance test. The calculation of turbine heat rate using heat & mass balance method, turbine efficiency is obtained by comparing the energy of 1 kW with turbine heat rate and multiplying 100%. The result of the average heat turbine calculation per performance test highest ie September 2016 is 3,51and Juli 2018 is 3,27. The average value of turbine efficiency in September 2016 was 29,03% and Juli 2018 was 33,84. Turbine power plant performance of PT. PJB UBJOM PLTU Pulang Pisau increase from 2016 to 2018 by 4,81 %.Keywords:Turbin Heat Rate, Efisiensi Turbin

Global economic and social development has led to the growth in demand for electrical power. Gas turbines play an essential role in many societies, and as the requirements for power generation increase, the power output and thermal efficiency of gas turbines must also increase. This paper presents one of the ways to improve the performance of the gas turbine with a study of exergy analysis of combined Brayton and inverse Brayton cycles with steam injected into the combustion chamber. The effect of variation of operating conditions (compression ratio and ambient temperature) on the performance of gas turbine (thermal efficiency, power) were investigated, the results were compared with the same cycle, but without injection with the analytical formulae of exergy and exergy destruction. The programming of performance model for gas turbine was developed utilizing the commercially available software IPSEpro. The analysis shows that the highest exergy destruction occurs in the combustion chamber. In addition, the performance has been improved by using steam injection by 11% in efficiency and 57% in power output and decrease linearly with the increase of the ambient temperature. However, steam injection increases the specific fuel consumption and heat rate. Thus, the thermodynamic parameters on cycle performance are economically feasible and beneficial for the gas turbine operations.

<div class="htmlview paragraph">The carbon dioxide removal assembly (CDRA) is an essential part of the International Space Station (ISS) environmental control and life support system. As such, this system is required to selectively remove carbon dioxide from the cabin atmosphere, and discharge it overboard to space vacuum. Verification of the many CDRA requirements is divided into analysis, demonstration, inspection, and test methods. This paper focuses on the results of protoflight performance testing conducted on the first deliverable CDRA. The results of this performance testing indicated that the CDRA design exceeded all of the performance requirements.</div>

In power plant engineering, gas turbine (GT) evaporative cooling is traditionally thought as one of the few power augmentation alternatives for existing plants. For most combined cycle plants operating at part load, the GT Inlet Guide Vanes (IGV) will throttle the air flow to the combustor to maintain the turbine exhaust temperature (TET) as high as possible, thus maximizing the overall combined cycle efficiency. The IGV air throttling results in a reduction of the turbine inlet air temperature (TIT) due to a reduction on the mass of fuel burned in the combustors as the available combustion air decreases due to IGV throttling to maintain an optimum air to fuel ratio, resulting on a lower TET compared with the same GT at base load. The compounded result of these effects limits the maximum steam production capacity on the heat recovery steam generator, particularly for the high-pressure section, hampering the efficiency of the steam turbine. The methodology developed in the subject study aims at counteracting the afore-mentioned effects by optimizing the evaporative cooler air/water ratio which results in the lower possible heat rate for full load and part load operation. By dynamically controlling the air/water ratio, a preheating effect can be achieved in the compressor inlet air, which results on higher exhaust gas temperature, thus augmenting the high-pressure steam production on the heat recovery steam generator and accordingly the steam turbine efficiency. For a newly built 907 MWe Combined Cycle Gas Turbine (CCGT) plant, application of the evaporative cooling part load optimization methodology presented in this study could lead to a potential reduction of up to 158kJ/kWh on heat rate and 9.318 g/kWh of CO2 emissions if compared with the same plant without dynamic control of the evaporative cooler air/water ratio.

The purpose of the performance test for Unit 1 of Maanshan nuclear power plant is to determine the electrical output and heat rate after the retrofit of the high pressure turbine in the latest refueling outage in 2012. The performance test was conducted in order to verify that the actual improvement in electrical output resulting from the replacement of the high pressure turbine meets the vendor’s guarantee. A total of two performance test runs was conducted in accordance with the ASME performance test code (PTC) 6. The measured electrical powers for the two test runs were 977.4 and 975.0 MWe, respectively, and the average value was 976.2 MWe. After correcting the electrical power to the rated conditions specified in the performance test procedure, the gross electric output was 983.2 MWe. The corrected heat rate for the two performance tests were 10365 and 10353 kJ/kW, respectively. The deviation between the two corrected heat rates was 0.11% and thereby satisfying the test code of 0.25% for the permitted test deviation. Moreover, the performance test results also demonstrated that the improvement in gross electrical output was 17.6 MWe comparing with the pre-retrofit performance test, which exceeded the 10.0 MWe basic performance guarantee by 7.6 MWe.

In a steam power plant, electricity is generated by a turbine-generator system driven by high-pressure steam produced by a drum-boiler. Changes in power output cause variations in the heating rate and water level, which, if not properly controlled, can lead to system shutdown. Water level control in such systems is still commonly performed manually or with PID controllers, which are less suitable due to the system’s nonlinear, MIMO characteristics and multiple operating points. Nonlinear Model Predictive Control (NMPC) has recently been adopted as it can handle these characteristics, but gradient-based optimization methods used in NMPC are prone to getting stuck in local optima. Genetic algorithms, as a gradient-free optimization method, offer an alternative by using a population-based approach, making them more capable of escaping local optima. This study aims to: (1) develop a Nonlinear Auto Regressive with Exogeneous Input (NARX) model representing the nonlinear drum-boiler system, and (2) design an NMPC controller based on genetic algorithms and compare its performance with NMPC using the interior-point method and PID gain scheduling in drum-boiler water level control system. The research involves collecting drum-boiler system data from industry, modeling with NARX, designing the genetic algorithm-based NMPC controller, tuning its parameters, and evaluating its performance. The challenge for the controller is to maintain water level despite varying power demands. The resulting NARX model achieved an RMSE of 5.2105 for training data and 3.6446 for testing data. The genetic algorithm-based NMPC maintained the water level effectively with an RMSE of 5.1944 and total control signal energy of 454590 (Ton/H)<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. The interior-point NMPC yielded an RMSE of 13.0492 and energy of 264990 (Ton/H)<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, while the PID gain scheduling controller had an RMSE of 13.5215 and energy of 1016600 (Ton/H)<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. This result demonstrates that the NMPC with genetic algorithm provides the best performance in maintaining water level stability with efficient control effort.

Presently, the major contribution in energy generation comes from conventional sources. Micro-hydropower is found to be a promising source of the future for rural electrification which can be economical and ecologically acceptable where conventional turbines are neither economical nor ecologically undisputed and cross-flow turbine is found most suitable. Many studies have been done in the past for different parameters in cross-flow turbine. Efficiency of turbine was found to be in lower range. In present study, CFD analysis is done for performance analysis of cross-flow turbine with variation in shaft diameter. From the results, it is found that on decreasing the diameter of shaft, pressure is found to be decreasing at the nozzle inlet. Maximum power output is obtained when the shaft diameter approaches zero value. Hydraulic efficiency of cross-flow turbine is found to be inversely proportional to shaft diameter. The increase in the value of hydraulic efficiency is about 5% when there is no shaft present as compared to the case when there is shaft of diameter 50 mm inside the runner.

Core performance tests for the JOYO MK-III upgrade

Augmentation of energy efficiency in the power generationsystemscan aid in decarbonizing the energy sector, which is also recognizedby the International Energy Agency (IEA) as a solution to attain net-zerofrom the energy sector. With this reference, this article presentsa framework incorporating artificial intelligence (AI) for improvingthe isentropic efficiency of a high-pressure (HP) steam turbine installedat a supercritical power plant. The data of the operating parameterstaken from a supercritical 660 MW coal-fired power plant is well-distributedin the input and output spaces of the operating parameters. Basedon hyperparameter tuning, two advanced AI modeling algorithms, i.e.,artificial neural network (ANN) and support vector machine (SVM),are trained and, subsequently, validated. ANN, as turned out to bea better-performing model, is utilized to conduct the Monte Carlotechnique-based sensitivity analysis toward the high-pressure (HP)turbine efficiency. Subsequently, the ANN model is deployed for evaluatingthe impact of individual or combination of operating parameters onthe HP turbine efficiency under three real-power generation capacitiesof the power plant. The parametric study and nonlinear programming-basedoptimization techniques are applied to optimize the HP turbine efficiency.It is estimated that the HP turbine efficiency can be improved by1.43, 5.09, and 3.40% as compared to that of the average values ofinput parameters for half-load, mid-load, and full-load power generationmodes, respectively. The annual reduction in CO2 measuring58.3, 123.5, and 70.8 kilo ton/year (kt/y) corresponds to half-load,mid-load, and full load, respectively, and noticeable mitigation ofSO2, CH4, N2O, and Hg emissions isestimated for the three power generation modes of the power plant.The AI-based modeling and optimization analysis is conducted to enhancethe operation excellence of the industrial-scale steam turbine thatpromotes higher-energy efficiency and contributes to the net-zerotarget from the energy sector.

Huge coal fueled power plants in the 1000MWel class are requiring high efficient steam turbines which can handle supercritical steam conditions up to 300bar and 600°C. Besides these boundary conditions, the capability for stabilising the grid fluctuations is also one key requirement. Siemens is focussing on this topic by using the so-called overload valve(s), which enhance the maximum amount of main steam mass flow entering the high-pressure turbine by use of additional valve(s). Using this technique, a power increase in the range of up to 20% is theoretically achievable. Siemens PG has collected a lot of positive service experiences throughout the past decades with this technique, and therefore this principle is being well established in the field. The connection between the additional steam mass flow passing through the overload valve and the standard blading path is somewhat downstream from the first stage. These connecting points can be varied (for this current turbine design) — if necessary — between the third and fifth stage after the turbine inlet. From an economic point of view, the approach of extending the power range via overload valves is even better than throttling the whole machine during standard operating condition and opening the valves fully at certain peak load requirements. Historically based, Siemens designs and manufactures reaction stages, ‘reaction turbines’, which must be thrust compensated via a separate piston to equalize and reduce the overall axial thrust down to a small number. Increasing the main steam temperatures up to the previously mentioned levels makes the internal cooling device of this thrust equilibrium piston a major key point for the whole turbine. No external cooling pipe-work or special materials are required. In Figure 1, a longitudinal cross-section 3D-view of the newly designed high-pressure turbine is drawn. The outer casing — at the steam inlet regime — is cast steel of 10% chromium content with significantly reduced wall thickness, whereas the outer casing at the hp-exhaust is a 1% chromium steel. The thrust-balancing piston on the shaft can be identified on the right hand side near the steam inlet channel. As noted further on, the steam outlet channels are both connected to the lower part of the turbine, whereas the inlet chambers are located at 3 o’clock and 9 o’clock, respectively. The outer casing has no horizontal splitting line; the turbine is being built as a barrel-design. This paper deals with the described turbine regarding the major design criteria from the thermodynamic point of view. Based on several calculations, the following design topics were covered: • Developing a turbine-internal cooling system for the thrust equilibrium/balancing piston as well as for the inner and outer casing. • Evaluation of staged piston with new internal cooling system adjusted for the impact on heat rate. • Quantification of all related mass flows, temperatures and pressures. • Axial thrust calculation to determine the required diameters of the staged piston. • General remarks concerning efficiency behaviour of hp-turbines with different geometrical designs.