Hot Steam Injection Research Articles

Numerical study of the impact of hot steam injection in the condensation flow through the low-pressure stage of steam turbine

Nowadays, steam turbines are the devices vastly used for energy generation in power plants. Accordingly, their performance and efficiency are crucially significant. In the last stages of the steam turbine, the presence of liquid phase decreases the efficiency and causes thermodynamic and dynamic losses. Various parameters can affect the steam flow and change the liquid droplets generated as well as the wetness fraction. In the present study, the hot steam injection parameter which affects the wetness decrease for the low-pressure stage of a steam turbine (LPST) has been investigated. First, the impact of hot steam injection (HSI) was studied on the wet steam flow parameters. Hot steam is injected on the suction surface of the stator with various slot angles and slot widths to select the optimal case. The goal of this study is to achieve the optimal value of injection variables to use this method further. To apply this, the LKHCE (Liquid mass, Kinetic energy, Hot steam, Condensation loss, Efficiency) criterion is used for all modes. Also, by examining the results of this method and using the TOPSIS, the optimal case can be selected. The condensing flow of wet steam through the stator-rotor blades is modeled using an Eulerian-Eulerian model and the SST k-turbulence model. Case 6 (angle 40°, slot width 0.1(cm)) for HSI is predicted as the optimal case, in which RL and RC decrease by 35.5 % and 34.6%, respectively, and RE is increased by 1.3%. The HSI caused a slight decrease in RK by 0.3% at the steam turbine stage’s outflow.

Perbandingan Performa Antara Treatment Hydrochloric Acid dan Carboxylic Acid Terhadap Kenaikan Produksi pada Sumur Minyak Berat

Duri steam flood is the largest hot steam injection project in Indonesia, facing challenges in preventing production declines. Objective project is showed decrease in production due to crustal deposition (scale). The Stiff and Davis method shows a Stability Index of 1.43, with a tendency for scale formation, especially CaCO3, in accordance with the Ryznar method. Increasing the production of x, yz layer wells in the Duri field, designing acidification stimulation with a pumping pressure of 400 psi, an injection rate of 2 bbl/minute and an acid volume of 600 gallons, after that comparing the performance of hydrochloric acid and carboxylic acid. Analysis showed that hydrochloric stimulation resulted in a significant increase in production of 115 BFPD / 8 BOPD (42% increase), while carboxylate stimulation showed a slower increase of 40 BFPD / 3 BOPD (24% increase). An economic evaluation shows chloride acidification produces an annual NPV gain of $48,002, compared to carboxylate acidification with an annual NPV gain of $22,554. Thus, chloride acidification proved to be economically profitable for the x, yz layers in the Duri field. This study highlights optimal acid stimulation strategies to mitigate scale-related production challenges in steam flood projects.

Implementation of hot steam injection in steam turbine design: A novel mean-line method coupled with multi-objective optimization and neural network

Low-pressure turbines usually work in wet conditions which causes both lifetime and efficiency reduction. Hot steam injection (HSI) which has received great interest recently, is a suggested solution to reduce wetness. There is a research gap in implementing HSI in the mean-line procedure, which is a conventional method of designing and analyzing turbines. In this paper for the first time, an object-oriented in-house mean-line code is developed with the ability of HSI calculation for steam turbines. The validation of code is performed with the 3D simulation of a 2-stage axial steam turbine. In addition, considering that HSI may reduce efficiency of the turbine due to mixing entropy generation, a multi-objective genetic algorithm optimization and a neural network is used to redesign the steam turbine. Mass fraction and total temperature of injected flow from the trailing edge of blade rows are the decision variables and, liquid mass fraction and efficiency of turbine are the objective functions. The comparison of Pareto front points reveals that the maximum possible improvement of quality and power relative to baseline is 5% and 10%, respectively. Furthermore, if efficiency is the desired objective function, by enhancing 1% of steam quality, it can be increased by 0.1%.

Optimization of inlet conditions of hot steam injection into the non-equilibrium condensing steam

Injecting hot steam into the cascade flow is one of the procedures for resisting losses and damages caused by condensation. In the current study, utilizing a 3D (three-dimensional) geometry for steam turbine blades, the hot steam has been injected into the steam cascade via the embedded channel. In the power plant industry, the hot steam injection process is done in two ways: constant pressure with a reservoir or constant mass flow rate utilizing a control valve. Therefore, considering these two methods and the TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) optimization method, the best temperature for injecting hot steam into non-equilibrium steam in a constant steam turbine blade has been gained. At the optimal temperature of 540 K at the constant pressure mode, Er (erosion rate ratio) and Lr (condensation loss ratio) were obtained as 66.6% and 30.7%, respectively, and Kr (kinetic energy ratio) showed a 0.6% growth in the hot steam injection mode, in comparison with the original mode. In addition, the economic cost of hot steam injection was calculated as 0.457 ($/hour). By the TOPSIS optimization method, the optimal temperature of hot steam injection, utilizing the constant mass flow rate method, has been obtained as 460 K, and the Er, Lr, and Kr values were 31.2%, 66.1%, and 88.48%, respectively at the optimal temperature. Moreover, the economic cost was 0.43 ($/hour). It is easier to control the steam injection by the constant mass flow rate method utilizing a control valve; therefore, the 460 K temperature and constant mass flow rate method are introduced as the optimal method.

Numerical analysis of hot steam injection through an embedded channel inside a 3D steam turbine blade

The steam expands rapidly and releases its latent heat at the last stages of steam turbines, forming a large number of tiny liquid droplets. This non-adiabatic process results in a sudden phenomenon known as condensation shock, leading to significant thermodynamic losses. Given that the condensation phenomenon can reduce the performance of steam turbines and shorten their lifespan, several studies in recent years have been proposed to eliminate liquid droplets, some focusing on surface heating, others on hot steam injection. However, providing a practical platform design for hot steam injection remains to be studied, which defines the primary goal of this investigation. In this research, a channel is installed inside the 3D turbine blade, allowing hot steam to enter and be stored there. Then, the stored hot steam enters the mainstream flow through eight injection holes with unequal mass flow rates from each hole. Six criteria are defined to see how hot steam injection contributes to decreasing wet steam losses and affects other key parameters. The results of CFD simulations indicate that hot steam injection reduces the rate of erosion, condensation losses, and wetness, respectively, by 58%, 28.5%, and 31.5%. Notwithstanding the advantages of this method, kinetic energy decreases by about 0.5%. This, however, seems to be acceptable due to the remarkable reduction of erosion and condensation losses. Finally, the obtained results indicated the fact that injecting hot steam through the designed channel costs roughly 0.45 ($/hour).

Reduction of water droplets effects in steam turbine blade using Multi-objective optimization of hot steam injection

As one of the most important equipment for energy conversion, steam turbine plays an irreplaceable role in industry. Due to the high velocity, the non-equilibrium condensation will take place in the steam turbine, emerging lots of tiny droplets. The tiny drops will not only deteriorate the efficiency but also endanger the safety of the steam turbine. The control of droplets size and liquid mass fraction is essential issue in steam turbine blade. One of the techniques that reduce the effects of the liquid phase on steam turbine blades is to inject hot steam. This study investigates hot steam injection in steam turbine blades for dehumidification by considering friction and thermal entropy generation. First, the injection parameters (injection location, slot width, pressure and temperature) are examined parametrically, and their impacts on the generated friction and thermal entropies, condensation loss, erosion rate, hot steam injection rate, and blade inlet flow rate are investigated. The optimization is carried out by the genetic algorithm. The results show the generated friction and thermal entropies increase through the hot steam injection, which, in an optimum state, can reduce the condensation loss, erosion rate, and blade inlet flow rate by 21%, 89%, and 4.9%, and raise the generated entropy by 22%. Moreover, the rate of the hot steam injection equals 4.3% in this condition.

Simultaneous Effects of Hot Steam Injection and Surface Heating through an Embedded Channel of Steam Turbine Cascade

One of the challenges of turbines in the last stages is the condensation of the water droplets of the steam flow; resisting against the droplets condensation could be one of the negative effects of the presence of droplets in the flow. The presence of droplets leads to erosion and damage to the blade as well as losses and efficiency drop in the turbine. Surface heating and hot steam injection are approaches suggested for solving the problem of droplets condensation; in the present study, a channel embedded in the turbine blade has been used to solve the problem of condensation. This is a step forward for making the hot steam injection and the blade surface heating practical. To prevent the condensation effects in the steam turbine cascade, two methods have been, simultaneously, utilized: surface heating and hot steam injection in a 3D study. As a result of applying the two heating methods mentioned, Er, Lr, and Wr decreased by 28.2%, 31.3%, and 61.5%, respectively. Moreover, the kinetic energy (one of the most important parameters in the turbine nozzle application) has increased by 0.35%. The results show a more surface temperature transfer on the blade's suction side.

An investigation of finding the best arrangement of hot steam injection holes in the 3D steam turbine blade cascade

An investigation of finding the best arrangement of hot steam injection holes in the 3D steam turbine blade cascade

Numerical Investigation of Hot Steam Injection Through a Channel Inside the Steam Turbine Blade

Numerical Investigation of Hot Steam Injection Through a Channel Inside the Steam Turbine Blade

Numerical Investigation of Hot Steam Injection Through a Channel Inside the Steam Turbine Blade

Numerical Investigation of Hot Steam Injection Through a Channel Inside the Steam Turbine Blade

The best angle of hot steam injection holes in the 3D steam turbine blade cascade

Steam turbines play an undeniable role in the power generation cycle. In this paper, in order to increase the efficiency of steam turbines, hot steam is injected between the steam turbine blades in 3D mode. Therefore, by defining five comparative criteria (liquid mass fraction, condensation loss, kinetic energy, hot steam injection ratio, and economic cost), injections with holes in various angles are investigated. For this purpose, the effects of the angle of the hot steam injection holes are discussed at the suction side on the two-phase flow parameters. The optimal angle for hot steam injection holes is selected (−60°), at which liquid mass fraction, condensation loss, and kinetic energy are reduced by 40%, 22%, and 1%, respectively. In addition, economic costs and hot steam injection holes are 0.56 ($/hour) and 0.07 for the suggested case.

Optimization variables of the injection of hot-steam into the non-equilibrium condensing flow using TOPSIS method

Nowadays, one of the concerns of the searchers is the increasing performance of industrial equipment. The phenomenon of spontaneous non-equilibrium condensation and the presence of droplets have caused efficiency and economic losses for industrialists. The hot steam injection causes reduction of the averaged radius droplets, liquid mass fraction, and erosion. In this study, an optimization analysis of the hot steam injection variables (location, angle, and width slots of injection) according to LKLEE criterion (Liquid mass fraction, Kinetic energy, Losses, Entropy, and Efficiency) has been performed by TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). Results show injecting at the Optimal mode has the highest kinetic energy and efficiency and less entropy. Also, Optimal mode is resulted a 1.05% increase of the Mach number than Original mode. Therefore, injection of hot steam at Optimal mode is caused a 9%, 60%, and 7.1% reduction in the droplet radius, losses, and liquid mass fraction compare to the Original mode, respectively. Overall, this optimal injection leads to the increased energy efficiency of industrial equipment at the output.

Experimental Study on Flow-Induced Corrosion of Casing and Tubing Steel for Heavy Oil Thermal Recovery Wells

The tubing and casing in the thermal recovery well are subjected to corrosion damage of multiple thermal fluid flow during the service period, which may cause safety accidents such as thinning, perforation and even fracture of the pipe wall. In this paper, the corrosion behavior of J55 casing steel and N80 tubing steel in flowing media were studied by using high temperature and high pressure reactor. The test results reflected the effects of single gas concentration and temperature of O2 and CO2 on tubing and casing corrosion. Comparing and analyzing the corrosion law of tubing in distilled water and produced water, the results of column corrosion rate under hot steam injection and production conditions were obtained, which indicated the difference of corrosion and the influencing factors of tubing in two working conditions.

Analysis of models for porosity evolution in reservoir during steam injection

Depletion of traditional hydrocarbon reserves leads to the development of extracting methods for heavy crude oil and bitumen characterized by extremely high viscosity. The most effective technology is the steam-assisted gravity drainage. The aim of this method is to decrease oil viscosity by injection of hot steam into the reservoir. Increase of temperature, pore pressure and change of stress-strain state during this process significantly affect porosity which is the key storage parameter of the reservoir. This work is devoted to the analysis of models for porosity evolution during the steam-assisted gravity drainage process. The authors have developed an original model to describe steam-assisted gravity drainage which includes the mass balance equation for a three-phase flow, the energy balance equation involving latent heat due to vaporization/condensation of water/steam and Darcy’s law for fluid filtration. Numerical implementation of the proposed equations was based on the pressure-saturation algorithm. The results have shown a substantial qualitative and quantitative disagreement between the considered models. Coupling of porosity with volumetric strain leads to the rise of its magnitude. Models relating porosity to pore pressure show simultaneous existence of high-porous (near the injection well) and low-porous (near the production well) areas. In case when porosity is dependent on effective stress a circular area of a compacted soil is formed. Therefore, to obtain a correct estimation of the oil production rate in an arbitrary reservoir it is necessary to define the prevailing mechanism of porosity evolution (volumetric strain, pore pressure or effective stress).

A comprehensive investigation of finding the best location for hot steam injection into the wet steam turbine blade cascade

In the power plant industry, a major part of energy losses in the thermodynamic cycle is related to the steam turbines, which are not made to work with wet steam flow, and the presence of the liquid phase causes efficiency reduction and mechanical damages such as erosion, which leads to high expenses due to the high cost of steam turbines. The present study used the hot steam injection (HSI) to decrease condensation loss and erosion rate. Location for HSI effects on the pressure distribution, Mach number, and liquid mass fraction of flow at the suction and pressure surfaces. For this purpose, several locations on suction and pressure sides were considered to select an appropriate location for injection. In this study, EEHIC (entropy generated, erosion rate, HSI ratio, inlet mass flow rate to the blade and condensation loss) method is used to select the most suitable HSI location. Results indicated that injecting on the suction side is more effective on mentioned parameters than the pressure side. HSI on the suction side (the lowest temperature in the center line of blade) decreased the condensation loss and erosion rate ratio by 81% and 99%, respectively, compared to the case of no injection.

In-situ heavy oil viscosity prediction at high temperatures using low-field NMR relaxometry and nonlinear least squares

Heavy oil and bitumen resources are the most abundant hydrocarbon energy source worldwide. However, due to their high viscosity, complex thermal enhanced oil recovery (EOR) methods are frequently applied to reduce it. Information about the distribution of oil viscosity within the reservoir can be used to help management of thermal EOR project. Nuclear magnetic resonance (NMR) downhole tools provide a non-destructive way to determine the oil viscosity without having to recover samples (core or produced oil) from the wellbore. Tests showed that the accuracy of the literature NMR viscosity models significantly decreases with temperature increase, making them ineffective for monitoring high temperature. Moreover, improved accuracy is required for high viscosity ranges of oil representative of original reservoir conditions.An enhanced NMR viscosity model was developed and tested on a suite of 23 Canadian heavy oils recovered from different reservoirs. Subsequently, the model was tested on a single bitumen sample at temperature range 26–200 °C. Results were compared to nine well-known NMR viscosity models from the literature, and in both cases, the enhanced model scored the lowest root mean square error (RMSE) in this study. Furthermore, a simple model optimization procedure was presented, which employs nonlinear least squares (NLS) regression.Experiments were carried out at the temperatures that correspond to those in the hot steam injection EOR treatments. The same methodology can be extended for use in cyclic solvent injection (CSI) where NMR model can detect the change of oil viscosity when the solvent vapor dissolves into the oil.

Non-Isothermal Compositional Model for Simulation of Multiphase Porous Media Flows

The research carried out in this work is aimed at the development of an explicit computational algorithm to simulate non-isothermal flow of multiphase multicomponent slightly compressible fluid through porous media. Such a modeling is necessary, for example, at solving practically important problems of hydrocarbon recovery via thermal methods and contaminated soil remediation via the hot steam injection. The original model and algorithm developed by the authors earlier draw the analogy with the quasi-gas-dynamic set of equations. Phase continuity equations were modified to get regularizing terms, while the type of equations was changed from parabolic to hyperbolic for the approximation by an explicit scheme with a mild enough stability condition. Since an adequate description of temperature-dependent porous media processes requires an explicit consideration of the transfer of mass and energy between the phases, the present work focuses on the generalization of the proposed approach to the case of multicomponent composition of fluids. Conservation laws are currently formulated for the components in terms of the mass concentrations of components in the phases. Constants of the phase equilibrium were used to close the set of equations. The developed model and algorithm have been verified numerically via test predictions of twoand three-phase flows, and, the phase transition of water into the gas phase at heating has been reproduced correctly.

Numerical Modeling of Heavy-Oil Recovery Using Electromagnetic Radiation/Hydraulic Fracturing Considering Thermal Expansion Effect

Production of heavy oil from deep/tight formation using traditional technologies (“cold” production, injection of hot steam, etc.) is ineffective or inapplicable. An alternative is electromagnetic (EM) heating after fracturing. This paper presents the results of a numerical study of heavy oil production from a well with hydraulic fracture under radiofrequency (RF) EM radiation. Two parameters ignored in our previous modeling studies, namely adiabatic effect and the thermal expansion of oil, are considered in the new formulation, while high gradients of pressure/temperature and high temperature occur around the well. The mathematical model calculates the distribution of pressure and temperature in the system of “well-fracture-formation.” The distribution of thermal heat source is given by the Abernetty expression. The mathematical model takes into account the adiabatic effect and the thermal expansion of heavy oil. The latter makes a significant contribution to heavy oil production. Multistage heavy production technology with heating is assumed and several stages are recognized: stage 1: “Cold” heavy oil production, stage 2: RF-EM heating, and stage 3: RF is turned off and “hot” oil production continues until the flow rate reaches its initial (before heating) value. These stages are repeated starting from the second stage. Finally, RF-EM heating technology is compared to “cold” production in terms of additional oil production and economics. When producing with RF-EM heating with power 60 kW (50 days in the second stages), the oil rate increased several times. Repeated RF-EM heating (25 days in the fourth stage) doubled the production rate. Near-well region temperature increased by ∼82 °C in the second stage with RF-EM heating. Temperature increased by ∼87 °C in the fourth stage with repeated RF-EM heating and production cycles. Economic analysis and evaluation of energy balance showed that the multistage production technology is more efficient; i.e., the lower the payback period, the greater the energy balance. With the increase in pressure difference, the payback period and energy balance increased linearly.

Study of oil filtration in porous media under the steam-assisted gravity drainage process

This work is devoted to the development and computer realization of a three-dimensional mathematical model describing the processes of flow, filtration and phase transition during the hot steam injection into a rock mass. The specific feature of the developed model is the possibility to take into account the dependence of thermophysical properties of each component in a multicomponent flow on time or spatial coordinates. It is assumed that considered media is a multicomponent system consisting of steam, oil and water filling the pore space. The developed model includes mass balance equation for components characterizing water and steam saturations, the condition of a fully saturated media to define the oil component of the flow, Darcy’s law for the filtration flow of the multicomponent stream and the law of conservation of energy taking into account the convective heat transfer and the source describing the «steam-water» phase transition. Computer realization of the proposed model is based on the transformation of the system of equations in such a way that the values of steam and water saturations as well as pressure act as unknown variables; representation of the resulting system of equations in a weak form and the introduction of additional stabilization terms. The adequacy of the proposed model and the efficiency of the developed approach to its implementation are illustrated by a three-dimensional numerical simulation of oil production process through the steam-assisted gravity drainage method in the oil sand.

Multi-objective optimization of hot steam injection variables to control wetness parameters of steam flow within nozzles

Abstract The formation of liquid droplets in the low pressure steam turbines has devastating impacts on the turbine adiabatic efficiency and also causes the mechanical damage of blades due to the occurrence of severe erosion phenomenon. Previous investigations have shown that the injection of steam can decrease liquid mass fraction as well as the size of the averaged radius of droplets. To exploit the maximum potentials of this method, the optimization of injection variables is necessary. In the present study, the numerical solution of wet steam flow by the injection of hot steam within convergent-divergent nozzles together with a multi-objective genetic algorithm method are used to evaluate the appropriate injection parameters. It is concluded that to reduce liquid droplet size by 66% and liquid mass fraction by 13%, an injection steam flow rate of 4% of the main stream flow rate with a temperature 1.8 times of inlet steam temperature is required. Such a reduction of liquid droplet size has an enormous effect on lowering the erosion damages of blades. Furthermore, the injection drives the liquid droplets away from the solid boundaries, which is also expected to reduce the possible mechanical damages to the blades and the casings of turbine.