Power Plant Condenser Research Articles

Effects of motive flow temperature on holding steam ejector Performance under Condenser temperature change by considering Entropy generation and Non-equilibrium condensation

The condenser plays a crucial role as one of the key components in a power plant, directly influencing its overall efficiency. Any alteration in the power plant’s efficiency has a substantial impact on both energy consumption and the environment. The holding steam ejector (HSE) is essential for condenser operation by creating a vacuum and effectively removing air. The primary objective of this study is to evaluation the motive flow temperature (MFT) by considering various parameters such as steam price, production entropy, air suction, and entrainment ratio (ER). The investigation focuses on different temperatures within the power plant condenser. The study examines the changes in MFT within the range of 350 ˚C to 400 ˚C, as well as the variation in condenser temperature (CDT) spanning from 47 ˚C to 67 ˚C. The results demonstrate that varying the MFT impacts the functional parameters of the HSE. As the MFT increases, there is an increasing trend in the ER. Simultaneously, there is a decreasing trend observed in the cost of steam production, production entropy, and air suction. When the MFT increased from 350 ˚C to 400 ˚C, the suction air mass flow rate for temperatures of 47 ˚C, 57 ˚C and 67 ˚C decreases by 2.22%, 2.09% and 1.99%, respectively. These results highlight the influence of temperature on various parameters, showcasing how adjustments in the MFT and CDTs can affect the flow characteristics and associated factors in the system.

Research on enhancing power plant net power by integrating modeling heat transfer and operation optimization of once-through cooling water system

For low power generation efficiency and water source thermal pollution caused by irrational operation of once-through cooling water systems (OCWSs) in condensing power plants, this paper advances a method to maximize the power plant net power by OCWS operation optimization and a 2 × 330 MW power plant is taken as a study case. First, the power plant thermodynamic system is simulated by Ebsilon to obtain exhausted steam parameters. Then, a heat transfer analysis method for the whole OCWS is investigated to calculate the system water temperature. Next, a maximum net power optimization model is deduced and established. Particularly, the model sets the temperature difference between OCWS outlet and inlet as a constraint. Finally, an improved firefly algorithm is employed to solve the model to get the numbers of constant-speed pumps and variable-speed pumps in operation and the frequency conversion ratio of the latter. This paper analyses the optimization under various scenarios and the sensitivity of optimization results. After optimization, the net power of the case power plant is increased up to 2080.5 kW, approximately 0.524 %. The OCWS temperature difference is decreased under most conditions. The method effectively enhances power plant net power and reduces drainage impact on the environment.

Modeling and Predicting Steam Power Plant Condenser Vacuum based on Small-sized Operation Data

Modeling and Predicting Steam Power Plant Condenser Vacuum based on Small-sized Operation Data

Numerical study of transient diffusion behavior of SF6 and He in a nuclear power plant condenser

Numerical study of transient diffusion behavior of SF6 and He in a nuclear power plant condenser

Computational Fluid Dynamics Modelling of the Temperature Distribution in Power Plant's Cooling Canal

Seawater used as a heat exchanger in the coal-fired power plant condenser system has a higher water temperature than the natural temperature of seawater. There was an increase in the temperature of the waters around the coal-fired power plant due to the discharge of boiling water reaching 6.50C. According to the regulations in force in Indonesia, the hot water temperature at the water discharge outlet should not be more than 20C of the natural temperature of seawater. The purpose of this study is to predict the pattern of temperature decrease in the temperature of the boiling water along the cooling line. The method used to predict temperature drop patterns along the cooling line uses a 3-dimensional CFD (Computational Fluid Dynamics) modelling approach with the Ansys Fluent 2023 RI application. The K-Epsilon turbulence model was chosen to describe the effect of flow turbulence on temperature changes. The modelling results were validated by comparing the actual measurements of the water temperature field data representing along the cooling line. The results showed that the performance of reducing the temperature of the water increased when passing through the cascade aeration downstream of the channel. The flow of water along the channel tends to be on the lower side, and downstream, the flow is on the left–middle side. The error calculation using MAPE resulted in 9.49%.

A comparative study of latent heat thermal energy storage (LTES) system using cylindrical and elliptical tubes in a staggered tube arrangement

Numerical analysis was performed to compare the thermal and hydraulic performance of the elliptical and circular tube geometries in the prototype-scale latent heat thermal energy storage (LTES) system. A staggered tube array configuration was used for the analysis where the tubes were placed horizontally. Commercial grade hexahydrate calcium chloride (CC6) was selected as a phase change material (PCM) due to its phase change occurring at room temperature. The study included a numerical analysis of the melting and solidification processes of the PCM within the tube array for both tube shapes, employing transient two-dimensional Navier-Stokes equations and a Realizable k-ɛ turbulence model to predict fluid flow and heat transfer. The enthalpy-porosity technique was used to model PCM melting and solidification. Numerical predictions indicate that the thermal performance for both tube shapes is almost indistinguishable during the melting and freezing processes. However, due to the aerodynamic shape of the elliptical tube, the pressure drop across the horizontal elliptical tube array is approximately 80% lower compared to that of the circular geometry. This reduced pressure drop implies that less pumping power will be required to achieve the desired flow rate across the tube bank, leading to economic advantages for the horizontal elliptical tube array. The proposed design can be used as a dry cooling technique employing an Air Cooled Condenser (ACC) in a thermal power plant.

Thermodynamic analysis of heat storage of ocean thermal energy conversion integrated with a two-stage turbine by thermal power plant condenser output water

The ocean thermal energy conversion (OTEC) system uses the temperature difference between warm sea surface water and deep cold water to generate electrical power. Due to the low-temperature difference between surface warm water and deep-sea cold water, the thermal efficiency of these systems is low compared to fossil fuel-driven power plants. In the present study, to propose a method for increasing the output power, thermal efficiency, and heat storage of an OTEC cycle, the warm water outlet of the existing thermal power plant is used instead of surface water which is conventionally employed in basic OTEC cycles. The results show that, considering average electrical net power in the basic OTEC cycle per month the energy and exergy efficiencies are 3.34 % and 17.2 %, respectively. Then, the suggested OTEC cycle is investigated using a two-stage turbine and reheating in terms of energy and exergy. Comparing the results obtained for the two configurations shows that, in the proposed cycle, the average output power is increased by 552 kWh per month, and energy and exergy efficiencies are improved by 0.048 % and 0.31 %, respectively. As an existing thermal cycle performance, a case study of a real Combined Cycle Power Plant (CCPP) is modeled with the proposed cycle. The results show that the average net electrical power is produced by 17.72 MWh per month by using the outlet water from the condenser of CCPP and the energy and exergy efficiencies have been increased by 1.432 % and 8.02 %, respectively Compared to the base cycle. Also, using condenser outlet warm water, an average of 18,829 tons per day of fresh water is produced, and the thermal efficiency of the CCPP is improved by 1.87 %.

Optimization Analysis of Multiple Steam Turbines and Condensers in Paper Mill Power Plant

The cooling tower water’s influence on turbines and condensers thermal efficiency were researched in this paper and the condenser working condition impact to turbines thermal efficiency was also discussed. Based on the basic model of turbines, condensers and cooling water, the optimization model for the system of turbines, condensers, cooling water and cooling water towers fan was proposed. One paper mill power plant which has multiple turbines, condensers and cooling water towers was taken as a case to verify the optimization model, the result showed that the optimization model was practical and useful for paper mill power plant; it can improve power plant efficiency and bring good economical performance for paper

Investigation of the performance of cold-end system in direct air-cooled power units under the influence of ambient winds

Direct air-cooled condensers in power plants rely on heat transfer with the atmospheric environment to discharge thermal energy. The heat transfer process becomes complicated in practical operations when ambient wind is involved. To examine the impact of wind on the heat transfer performance of direct air-cooled condensers, this paper took into consideration three different wind directions, namely, headwind, crosswind and tailwind, as well as four different speeds (3 m/s, 6 m/s, 9 m/s, and 12 m/s), and numerically investigated their influences on the thermal performance of a 600 MW direct air-cooled power unit. The variation in ventilation rates and inlet air temperatures among the cells under the influence of ambient winds are also studied. Simulation results indicated that ambient winds induced thermal air re-circulation and air backflow phenomena in the air-cooled island. The cells located on the windward side were significantly affected in all three wind direction conditions. The ventilation rates and inlet air temperatures among the cells were not uniform, showing an overall increasing trend. In particular, negative pressure zones were generated under tailwind conditions, severely impacting air-flow rates at the fan inlet, and inlet air temperatures of cells. These phenomena became more pronounced with increasing wind speeds.

Simulation study on transport characteristics of leakage gas from the condenser of power plant

Exploring the transport characteristics of leakage gas in the condenser can facilitate quicker identification of leak points when using Helium tracer gas method for detection. We construct a 3-D physical model of the condenser to simulate the Helium gas leakage process within the tube bundle. On the steam side, we adopt RNG k-?, porous media, steam condensation, and convective diffusion models to describe steam and leakage gas-flow. On the waterside, we use the tube bundle thermal resistance model to describe the steam-water heat transfer. The research concludes with three key points. When the centripetal pressure gradient is insufficient, there will be leakage gas enrichment, resulting in flowing out in the form of diffusion. When there is no centripetal pressure gradient in the tube bundle region, it will extract only a small amount of upstream leakage gas along with steam through the flow. When reaching a stable level for leakage gas, the leakage intensity is proportional to the outlets? flow rate but is independent of the transport form. The deviation of the mass-flow rate decreases with the mesh quantity increasing, which is less than 2% when the mesh quantity is over 638228. The deviation between simulated and actual values of the two parameters is less than 5%, which reveals the good agreement between numerical calculation and actual work conditions. These conclusions can assist employees and researchers in evaluating data on leak points and enhancing detection techniques.

Dual Stratification on the Double Diffusive Magnetohydrodynamics Flow of Nanofluids with Dissipation Effects-Revised Buongiorno Model

We analyze the effects of double stratification and dissipation on the hydro magnetic free convection flow of nanofluids over a vertical plate in this work. Considered two different kinds of nanofluids, such as copper and alumina–water nanofluids. By employing the similarity transformation, partial differential equations are converted into non-linear ordinary differential equations, which can be numerically computed with MATLAB. In practical situations where the heat and mass transfer mechanisms run simultaneously, the analysis of natural convection in the influence of double stratification is a fundamentally interesting and important problem, because of its broad range of engineering applications. These applications include the rejection of heat into the environment, such as lakes, rivers, and seas; the storage of thermal energy, such as solar ponds; and the transmission of heat from thermal sources, such as the condensers of power plants. To highlight the impact of double stratification and dissipation on the hydromagnetic free convective flow of nanofluid over a vertical plate, a wide variety of parameter values are used. The numerical outcomes for the different parameters of velocity, temperature, volume fraction, and concentration are obtained and displayed graphically. The skin friction coefficient and reduced Nusselt number are also determined numerically and tabulated.

Determining steam condensation pressure in a power plant condenser in off-design conditions

Determining steam condensation pressure in a power plant condenser in off-design conditions

Electricity and water cogeneration using a small PWR of 75 MW(th) coupled to a DCMD desalination plant with heat recovery

The use of a small PWR of 75 MW(th) coupled to a Direct Contact Membrane Distillation (DCMD) desalination plant with heat recovery, for cogeneration of electricity and water, is investigated here. Part of the heat used for desalination is waste heat from the power plant, as the desalination plant collects warm seawater from the power plant condenser instead of taking water directly from the sea. Two distinct coupling strategies are considered. In the first one, the additional heating required for the desalination process is obtained from steam extractions, taken at the low pressure turbine, after the extracted steam has already done a substantial amount of mechanical work. The second strategy is based on splitting the steam produced in the steam generator into two parallel Rankine cycles. The condenser at one of those cycles is set to operate just below atmospheric pressure in order to provide extra heating, at a higher temperature, for the desalination plant. Both strategies analysed in this work, relying on the use of waste heat and employing a DCMD desalination plant with efficient heat recovery, are shown to be competitive with other well established thermal desalination technologies currently used in nuclear cogeneration plants, such as MED and MSF.

Modeling the cleaning cycle dynamics for air cooling condensers of thermal power plants: Optimization and global sensitivity analysis

Modeling the cleaning cycle dynamics for air cooling condensers of thermal power plants: Optimization and global sensitivity analysis

Study on the Influence of the Tube Bundle Arrangement on the Performance of Condenser in Nuclear Power Plant

Nuclear power generation technology is obviously a safe and economical way of generating power in modern society. As the low temperature heat source, the condenser of the nuclear power technology condenses the steam into condensate water and then establishes a certain degree of vacuum at the exhaust port of the turbine. The operation of condenser is critical to the nuclear power generation technology. In this paper, the influences of the arrangement of tube bundles on the condenser of nuclear power generation technology were investigated. Three types of condensers, including the church window type, the centripetal type, and the UT type, were analyzed using Ansys Fluent software. The steam flow velocity distribution, air concentration distribution, temperature distribution, and heat transfer coefficient distribution were studied. Under specific design conditions, the flow velocity in the church window type was large, the exhaust air concentration was small, the maximum flow rate distribution was relatively reasonable, and the air concentration distribution was more concentrated. The performances of the centripetal type and the UT type were slightly worse, and the steam condensation was less. In contrast, the condensation of the church window type was large, the relative performance was high, and the heat transfer performance was better.

A numerical study on film condensation of steam with non-condensable gas on a vertical plate

The film condensation of steam is very common in several industrial areas, such as condensers in power plants, seawater desalination, and air-conditioning systems. In some studies, the non-condensable gas and liquid film are overlooked for the sake of simplicity. To provide an integral computational scheme, in the present study, the film condensation of steam in the presence of non-condensable gas on a vertical plate has been simulated using a two-dimensional CFD model combining a wall condensation model and volume of fluid (VOF) model. After verification, the proposed computational scheme is used to simulate the steam condensation process, with the mass fractions of non-condensable gas varying from 5% to 45%. The results indicate that the concentration of non-condensable gas in the boundary layer decreases gradually with the condensation process, resulting in a decline in the synergy between temperature and velocity field. It can also be found that the fluctuation of the liquid film can influence the concentration distribution of the non-condensable gas layer. For cases with high concentrations of steam, the thermal resistance of liquid film can reach more than 20% of the total thermal resistance, which should not be ignored.

Assessment of Thermodynamic Efficiency of the Belarusian Energy System. Part 1

The energy system is one of the foundations of a modern state, so, the need for its successful development and functioning is beyond doubt. In this regard, an objective assessment based on a set of indicators (viz. economic, energy and thermodynamic) is relevant. However, the traditional assessment of the operation of the energy system is carried out on the basis of such characteristics as the specific consumption of conventional fuel for electricity generation and heat release, which does not provide a comprehensive picture and is not always applied correctly. In this article, for the first time on the basis of the exergetic method, the calculation of the exergetic efficiency is considered. The use of this indicator makes it possible to obtain an objective assessment of the thermodynamic efficiency of such a complex formation as the energy system of a modern country in the easiest way. As an example, the unified energy system of Belarus in general and condensing power plants in particular have been analyzed for a fairly long period (2000–2021) and in various characteristic time periods. The method of calculating the exergetic efficiency is described. The results obtained are presented graphically. Attention is paid to the issue of the acceptability of the error when generalizing data on the initial flows of primary energy resources and product flows of centralized generating sources of the energy system. The contribution of condensing power plants to the total volume of electricity generation is analyzed, the most advanced of them are determined from a thermodynamic point of view. The calculation of their energy and exergetic indicators was carried out; the changes associated with the commissioning of the Belarusian NPP were considered. The conclusion is made that further reconstruction of energy sources of the power system in order to reduce the relative weight of natural gas in the incoming part of the energy balance to 50 % is expedient. This can be achieved by increasing the thermodynamic efficiency.

Investigation of air-cooled condenser’s operating parameters in modern thermal power plant

Air-cooled condensers in thermal power plants have recently become increasingly popular. Besides all the advantages they have, like no demands for water supply on the plant site and no need for taking care of environmental regulations, they also have some serious disadvantages. One of the biggest disadvantages air-cooled condensers do have is precisely the nature of the Earth?s atmosphere being their low temperature reservoir. Low density and low heat capacity of the air as the cooling medium combined with extremely stochastic behavior of the atmosphere itself put some serious challenges in front of the air-cooled condenser?s proper and steady functioning. In this paper, the operating parameters of the air-cooled condenser in the chosen thermal power plant were investigated to gain a clearer insight into the influence of the atmospheric changes on its entropy generation and consequently on its efficiency. Also, the acquired results were further proposed as a starting point for potential optimization of the process inside the device.

Titanium tube blocking margin and defect management for condenser in nuclear power plant

Titanium tube blocking margin and defect management for condenser in nuclear power plant

Evaluation of the Process of Condensation of Water Vapour in the Presence of Deposits Using a Single Pipe in the Heat Exchanger of a Condensing Power Plant as an Example

Evaluation of the Process of Condensation of Water Vapour in the Presence of Deposits Using a Single Pipe in the Heat Exchanger of a Condensing Power Plant as an Example