Horizontal Steam Research Articles

Study of the Mechanical Behavior of a Single-Cylinder Horizontal Steam Engine with a Crosshead Trunk Guide through the Finite-Element Method

Study of the Mechanical Behavior of a Single-Cylinder Horizontal Steam Engine with a Crosshead Trunk Guide through the Finite-Element Method

Evaluation of the Pilot Test Effect of Steam Stimulation in Horizontal Wells of Sand Bodies 1-1308 in Bohai L Oilfield

In order to reduce the risk of large-scale thermal recovery of heavy oil in Bohai Oilfield, L Oilfield is selected to carry out horizontal well steam stimulation pilot tests. Previous studies have summarized the rationality of the injection parameters and initial production characteristics of this experiment, but the evaluation of its development effectiveness is still blank. Based on the study of the decline law of A23H well cold recovery using reservoir engineering methods, this article evaluates the initial production capacity, production increase effect, technical recoverable reserves, and throughput cycles of steam stimulation. The results show that the thermal recovery production of steam stimulation is three times that of cold recovery, which can significantly improve the production capacity of a single well. The initial daily oil production of two wells is 74m<sup>3</sup>/d and 90m<sup>3</sup>/d, respectively, which is 3.0 times and 3.6 times that of the initial production of cold recovery, exceeding the design level of the reservoir; The first round has the best yield increase effect, with an average daily oil increase of 31m<sup>3</sup>/d, and gradually decreasing thereafter. By the fifth round, it was only 13m<sup>3</sup>/d. In terms of yield increase multiples, each round can reach about 2 times; The technically recoverable reserves are 19.03 × 10<sup>4</sup>m<sup>3</sup>, requiring 8-9 rounds. Through this performance evaluation, we have strengthened our confidence in promoting the application of steam injection technology in Bohai Oilfield to achieve large-scale thermal recovery.

Analysis from the Functional Viewpoint of a Single-Cylinder Horizontal Steam Engine with a Crosshead Trunk Guide through Engineering Graphics

This paper explores a historical innovation created by Henry Muncaster: a stationary steam engine featuring a single-cylinder horizontal design with a crosshead trunk guide. Through the application of engineering graphics techniques, we have elucidated the functioning of this invention by developing a 3D CAD model based on the original drawings published in Model Engineer magazine in 1957. However, the geometric modeling process faced challenges due to missing and erroneous dimensions for several components. Consequently, dimensional, geometric, and movement constraints were applied to ensure the coherence and functionality of the 3D CAD model, alongside conducting an interference analysis. Ultimately, the proper alignment of the cylinder and crosshead was ascertained, which is crucial for maintaining uniform forces and motions within the steam engine. This alignment is pivotal for achieving balanced operation, minimizing vibrations, and enhancing the overall efficiency of the invention.

Validation of the STEG Code against Experimental Data on Hydrodynamics of a Horizontal Steam Generator

Validation of the STEG Code against Experimental Data on Hydrodynamics of a Horizontal Steam Generator

Study on Characteristics of Steam Chamber and Factors Influencing Nitrogen-Assisted Vertical–Horizontal Steam Drainage Development

With the notable achievements attained through the implementation of steam-assisted gravity drainage (SAGD), the vertical–horizontal steam drive (VHSD) emerges as a pivotal technological advancement aimed at significantly enhancing the efficiency of thin reservoir heavy oil recovery subsequent to steam cyclic stimulation. The inclusion of nitrogen assistance has proven effective in enhancing the efficacy of gravity drainage techniques in reservoir development. However, it is noteworthy that this method has only led to improvements in approximately 50% of the well groups within the observed field. The comprehensive evaluation index of VHSD was proposed, and as the objective function, it was determined that the greatest contribution to the VHSD technique lies in oil saturation, accounting for 40% of the overall evaluations. This differs from conventional SAGD operations, where reservoir thickness serves as the primary determinant. Building upon an enhanced physical simulation similarity criterion, two comparative injection scheme experiments were conducted to explore the impact of nitrogen injection on the performance of VHSD and the characteristics of the steam chamber. Nitrogen is distributed in the vicinity of the steam chamber, leading to the formation of a dual mechanism characterized by ‘top heat insulation and lateral traction’ on the steam chamber. The lateral traction accounts for approximately 25% of the team chamber volume. Additionally, the inducement of nitrogen causes a downward displacement of crude oil, resulting in its accumulation within the high-temperature region of the steam chamber. This, in turn, enhances the contact area between the high-temperature steam and the crude oil, ultimately leading to improvement in production efficiency. Further validation of the impact of nitrogen on steam lateral traction and interlayer steam drainage within the reservoir was confirmed using Xinjiang oilfield testing. The well temperature increased from 75 °C to 130 °C.

Comparison of thermal hydraulic performance between horizontal and vertical steam generators in nuclear power plants

Abstract Steam generators (SG) for Nuclear Power Plants (NPPs) are important large-sized metal consuming equipment of nuclear power installations. Efficiency of steam generator operation determines the overall service life of the whole nuclear facility. Vertical steam generators are used normally in North America, Europe and South East Asia, but horizontal steam generators are currently of great importance to reduce building heights and construction costs that govern the overall cost of new nuclear power plants. The objective of the current study is to measure the performance of nuclear steam generators in NPPs through comparative assessments of vertical and horizontal configurations. For this purpose, the vertical U-tube steam generators of a typical 4-loop Pressurized Water Reactor (PWR) was replaced by a VVER-1000 horizontal steam generators to evaluate the horizontal SG performance, at the same plant conditions and characteristics, in comparison with the vertical SG. The thermal hydraulic system code RELAP5 was used in the current work to perform the required analysis, during steady and transient scenarios.

Investigation on thermohydraulic characteristics of novel superheated steam supply system for low temperature nuclear heating reactor

In a new Chinese low temperature nuclear heating reactor (NHR) demonstration project, a novel superheated steam supply system was designed to meet new requests for the steam produced in the secondary circuit. Different from the previous version of NHR200-II, which used a vertical steam generator to produce saturated steam, this newly designed system features a preheater, a horizontal steam generator, and a superheater for generating superheated steam. Numerical simulation method was used to investigate the feasibility and thermal hydraulic characteristics of this novel superheated steam supply system. The simulation results verify the accuracy and reliability of the system design, showing that the three heat exchangers can operate in coordination under different power levels, and the superheated steam generated in the secondary circuit can meet the users’ requirements. The system also demonstrated a remarkable ability to recover from sudden disturbances within 13.64 % change of the secondary circuit mass flow rate or 2.39 % change of the secondary circuit temperature under full power condition. Besides, the system has a power adjustment ability of ±10 %, and the system can quickly return to the new steady state. RELAP5 simulation results can provide theoretical guidance for the subsequent experimental research of this novel superheated steam supply system.

Experimental and simulation studies of oxygen-blown, steam-injected, entrained flow gasification of lignin

This article presents results from experimental and simulation studies on a laboratory-scale pressurized O2-blown Entrained Flow biomass gasification Reactor (EFR) using pulverized commercial lignin pellets as feedstock. The primary focus lies in the assessment of the EFR’s performance indicators such as the H2/CO ratio, the Cold Gas Efficiency (CGE), and the Carbon Conversion Efficiency (CCE). The gasifier was operated at an absolute pressure of 8.2 bars, with varying amounts of O2 and steam. In the first series of experiments, the O2 equivalence ratio varied between 0.2 and 0.8, with no steam injection. This yielded a maximum CGE of 47%, a CCE of 94%, and an H2/CO ratio within the range of 0.4–0.7. In the last series of experiments, a perforated horizontal steam tube was installed allowing for a variation of the steam-to-biomass ratio (S/B), between 0.5 and 1.5. At a S/B of 1.5, the CGE and the CCE were at their highest levels of 91% and 99%, respectively. Based on the experimental setup, a 3D multiscale Eulerian-Lagrangian computational particle fluid dynamics (CPFD) model for the reactor was developed and validated against the experimental data. This model was then employed to explore the impacts of reactor temperature, S/B, equivalence ratio (λ), and the lignin particle size distribution (PSD) on the gasification process. The findings show that increased reactor temperature enhances H2 and CO production. Higher S/B ratios lead to greater H2 production but reduced CO production. Increased S/B ratios improve both CGE and CCE. Larger particles and higher λ values decrease CO and H2 production. Without steam injection, the peak CGE occurs at λ ≈ 0.45, corresponding to complete CH4 conversion. Beyond this point, as λ increases, reactor temperatures rise while CGEs decrease. Simulations reveal the optimal λ range for steam injection is 0.15–0.35. A sensitivity analysis highlights the significant impact of reactor temperature on H2 and CO production. While λ shows high sensitivity for H2 production, the S/B ratio exerts a greater impact on CO production.

A thermal-hydraulic and control model for a Pb-Bi micro reactor

Lead-bismuth cooled reactor offers substantial potential in terms of safety, design simplification, proliferation resistance and economic performance. A Pb-Bi micro reactor was studied in this paper, and the primary coolant system models including the horizontal helical-coil once-through steam generator (S/G) model based on four-equation drift-flux, the annular gas tank pressurizer model and the core model, and the control model based on “load following” mode were established. Adopting the fully implicit scheme, Gear algorithm, quasi-Newton method, Steffensen method and first-order Taylor polynomial expansion method were flexibly selected in each module for numerical solution. The steady-state results show that the proposed model can successfully simulate the characteristics of the Pb-Bi micro reactor, and the steady-state calculation results are in good agreement with the design values. The transient results show that the proposed model can successfully simulate the dynamic process under different loads, and can realize the “load following” operation mode.

Dynamic process simulation of a 780 MW combined cycle power plant during shutdown procedure

The share of variable renewables in power generation is increasing due to the push to reduce emissions, and the flexibility of conventional power plants has become a major concern. There are many ways to increase the flexibility of existing power plants and implement a more flexible system for the future, such as a fast start-up procedure and higher load change rates. In this study, a 2D dynamic process simulation model of a reference combined cycle power plant is presented to increase the flexibility of cyclic operation by investigating, for the first time in the literature, the shutdown procedure using APROS software. The 780 MWel Tambak Lorok reference combined cycle power plant consists of the GE 9HA.02 heavy-duty gas turbine and a three-stage horizontal heat recovery steam generator with reheat. Several steps were considered to improve the accuracy of the developed dynamic process simulation model, including varying the steam leakage to the atmosphere to control how much thermal energy remains in the heat recovery steam generator, changing the shape loss coefficients of the tubes to achieve higher or lower recirculation, and decoupling the reheater and the intermediate pressure drum. The developed model is validated with real data from three different combined cycle power plants in different countries with various capacities. The comparison shows that the developed dynamic simulation model can accurately represent the real behaviour of natural convection in the heat recovery steam generator. The main outcome was to provide detailed information on the shutdown procedure of large-scale combined cycle power plants, addressing the aspect of the development of new start-up strategies to reduce the time required for the start-up procedure.

Physical Simulation of Steam Absorption Characteristics in Horizontal Wells of Super Heavy Oil Reservoir

In the process of dual Horizontal well SAGD development of super heavy oil, the steam absorption balance of upper horizontal steam injection well is an important factor to determine the development effect of SAGD. The factors affecting the steam absorption of upper horizontal wells involve reservoir permeability, steam injection technology, steam injection parameters, etc. The physical simulation method is used to study the influence degree of each specific factor and improvement measures. Based on the similarity criterion, the reservoir scale model is designed and made according to the oilfield prototype, and the simulation experiment is carried out on the steam absorption characteristics and influencing factors along the horizontal wellbore. The experimental results show that the steam injection rate, non condensable gas, the location of the steam injection string and the reservoir permeability have great effects on the steam absorption of the reservoir. The heating uniformity along the horizontal well can be improved by properly increasing the steam injection speed, adding a certain amount of non condensable gas to the steam, and the position of the steam injection string end in the relatively low permeability area of the reservoir. This achievement has a strong guiding significance for improving the steam absorption balance of horizontal wells and improving the development level of dual level SAGD.

Degradation analysis of horizontal steam generator tube bundles through crack growth due to two-phase flow induced vibration

A correct understanding of vibration-based degradation is crucial from the standpoint of maintenance for Steam Generators (SG) as crucial mechanical equipment in nuclear power plants. This study has established a novel approach to developing a model for investigating tube bundle degradation according to crack growth caused by two-phase Flow-Induced Vibration (FIV). An important step in the approach is to calculate the two-phase flow field parameters between the SG tube bundles in various zones using the porous media model to determine the velocity and vapor volume fraction. Afterward, to determine the vibration properties of the tube bundles, the Fluid-Solid Interaction (FSI) analysis is performed in eighteen thermal-hydraulic zones. Tube bundle degradation based on crack growth using the sixteen most probable initial cracks and within each SG thermal-hydraulic zone is performed to calculate useful lifetime. Large Eddy Simulation (LES) model, Paris law, and Wiener process model are considered to model the turbulent crossflow around the tube bundles, simulation of elliptical crack growth due to the vibration characteristics, and estimation of SG tube bundles degradation, respectively. The analysis shows that the tube deforms most noticeably in the zone with the highest velocity. As a result, cracks propagate more quickly in the tube with a higher height. In all simulations based on different initial crack sizes, it was observed that zone 16 experiences the greatest deformation and, subsequently, the fastest degradation, with a velocity and vapor volume fraction of 0.5 m/s and 0.4, respectively.

Hydrodynamics of vapor-liquid flows in curvilined channels of separation devices of power plants

The main factor that affects the efficiency of the separation process is the lack of contact with the surface of the shutter when moving in the flow of small droplets of wet steam. This process depends on the physical and chemical properties of the wet vapor, the dispersion of the droplets, the parameters of the movement of the two-phase medium, adhesion and edge angle, and the geometry of the channel. Purpose. Determination of the limit modes of operation of separation shutter devices depending on the dispersion and quantity of droplet liquid, flow parameters and geometric characteristics of curved channels. Methodology. The methodology is based on the analysis of the physical model of the movement of a two-phase medium under the action of mass and gravitational forces in a curved horizontal channel. Findings. A mathematical model is presented for determining the trajectory of a liquid droplet in a curvilinear corrugation channel of the louvered package of a separator-superheater. The main conditions of film destruction and dynamic droplet break-up are defined. A method for expanding the range of stable operation of separation devices is proposed. Based on the obtained correlations, the design of the blind package is optimized. Originality. Based on the analysis of the physical model of the movement of a two-phase medium in a curved horizontal channel, a mathematical model was developed and the limit of capture of the dispersed phase was determined. Practical value. The presented results allow optimization of separation devices of boiler drums, horizontal steam generators and steam superheater separators of the II circuit of VVER-1000, fuel preparation systems of GTU.

DESIGN CHARACTERISTICS OF THE HORIZONTAL STEAM GENERATOR PGV-1000

The materials of the article consider the design characteristics of horizontal steam generators PGV-1000 for WWER NPPs. The NPP steam generator, in particular the PGV-1000 steam generator, is a specific heat exchange unit. This unit, together with a nuclear reactor and a steam turbine, is one of the main equipment of multi-circuit (double-circuit) steam turbine NPPs. The steam generator produces working steam using heat dissipated from the reactor core by the cooling medium and sent to the heat exchange surface of the steam generator. NPP steam generators, connecting the contours of the coolant and the working substance, equally belong to each of them. The heat-absorbing medium in the steam generator is the working substance (water, steam). PGV-1000 type NPP steam generators with pressurized water reactors produce dry saturated steam. The requirement to maintain high purity of the coolant is due to the heat transfer surfaces of such steam generators made of austenitic stainless steel with electropolished surfaces. WWER reactors do not allow the coolant to boil in the core, so the temperature of the coolant at the outlet of the reactor (at the inlet to the steam generator) is always lower than the saturation temperature corresponding to the water pressure in the coolant circuit. Underheating of the coolant to the saturation temperature (approximately 25 ÷ 30 °С) guarantees the exclusion of vaporization even in the most loaded reactor channels. The design characteristics of modern horizontal steam generators such as PGV-1000 of various modifications provide high technical and economic performance of NPP units with WWER-1000 and high maintainability, which allows to extend the service life of domestic NPPs.

Modeling of horizontal steam injection in a water pool

A comprehensive understanding of the direct contact condensation (DCC) phenomena of steam discharged into a subcooled water pool is essential for the nuclear engineering field. DCC is the most rapid and efficient way to condense high-pressure and high-temperature steam with simple engineering systems. However, the pressure oscillation due to the rapid condensation and small length and time scales of turbulent two-phase flow make the investigation of DCC phenomena challenging either by experiments or with numerical simulations.This paper presents the computational fluid dynamics (CFD) simulations of the small-scale separate effect test facility (SEF-POOL) experiment of Lappeenranta-Lahti University of Technology (LUT University). In the SEF-POOL test, the steam was injected using the orifice of a diameter of 16 mm. All simulations were performed by employing the compressible two-phase solver of OpenFOAM which was based on the Eulerian–Eulerian two-fluid approach. The interfacial heat transfer between steam and water was modeled by using the Nusselt number formulation of Coste (2004). The Rayleigh–Taylor interfacial (RTI) area model of Pellegrini et al. (2015) was applied for the interfacial area modeling. In this work, the formation and collapse of the steam bubbles are studied using the extended pattern recognition based image analysis algorithm. The pattern recognition (PR) algorithm is based on the video material recorded during the SEF-INF2 experiment of the SEF-POOL test facility.The presented study show that if the two-phase interface is rough and smear into the subgrid scale, the interfacial area density calculation solely with the volume fraction gradient is inadequate for predicting rapid condensation rates. Results indicate that rapid and high interfacial accelerations in DCC trigger interfacial instabilities which increased the interface roughness and total interfacial area consequently. Thus, interfacial area modeling with the RTI increased the total interfacial heat transfer rate in the simulations. The achieved results exhibit that the selected modeling approach captured the rapid bubbling condensation oscillation mode of the SEF-POOL test. Presented results demonstrate that image analysis and pattern recognition have great potential in thermal-hydraulic research that can be beneficial for direct contact condensation and phase-interface dynamics model development.

Mathematical model of the horizontal steam generator PGV-1000

The materials of the article consider the design characteristics of horizontal steam generators PGV-1000 for WWER NPPs. The NPP steam generator, in particular the PGV-1000 steam generator, is a specific heat exchange unit. This unit, together with a nuclear reactor and a steam turbine, is one of the main equipment of multi-circuit (double-circuit) steam turbine NPPs. The steam generator produces working steam using heat dissipated from the reactor core by the cooling medium and sent to the heat exchange surface of the steam generator. NPP steam generators, connecting the contours of the coolant and the working substance, equally belong to each of them. The heat-absorbing medium in the steam generator is the working substance (water, steam). PGV-1000 type NPP steam generators with pressurized water reactors produce dry saturated steam. The requirement to maintain high purity of the coolant is due to the heat transfer surfaces of such steam generators made of austenitic stainless steel with electropolished surfaces. The design characteristics of modern horizontal steam generators such as PGV-1000 of various modifications provide high technical and economic performance of NPP units with WWER-1000 and high maintainability, which allows to extend the service life of domestic NPPs.

Improvement of Steam Injection Efficiency in Horizontal Well with the Semi-Analytical Model: A Case Study of Liaohe Oilfield Steam Injection Well

As China’s largest heavy oil field, Liaohe oilfield encounters many problems after long-term thermal recovery, including high water percentage at early production stage, steam channelling and water cresting. To solve the above problems, the steam flow behavior and thermal characteristics in horizontal well should be understood. In this paper, a semi-analytical model is proposed to investigate the thermal properties and heat losses along the steam injection horizontal wellbore. The flow pattern is determined by the modified Beggs-Brill method and different conservation equations are incorporated to calculate the steam pressure, steam temperature and steam quality. The model shows good consistency with the field data of the horizontal steam injection well in Liaohe oilfield. The sensitivity analysis shows that the steam quality along the wellbore is strongly affected by the steam pressure, steam injection rate and steam quality at the heel. Generally, the steam injection rate does not have significant effect on steam pressure, steam temperature and steam quality. The model is then used to optimize the injection parameters of Well XH27 to improve the steam injection efficiency. After optimization, more steam is injected to the formation to heat the region near the wellbore, which leads to a higher production rate. In summary, this study presents a semi-analytical model to calculate the thermal properties of steam and the model can be used to optimize steam injection process for field application.

Numerical investigation on the thermal-hydraulic performance of separated structure steam generator with different tube arrangements

The horizontal steam generator is generally used in nuclear power plant and industry to produce steam. To increase the heat load and reduce the size, a steam drum can be added above the shell. However, it makes the overall flow of water cycle complicated. In this article, the two-phase boiling flow and heat transfer inside tube bundle under the separated structure has been investigated numerically based on the previous experiment. The Drift-Flux model was utilized to solve the equations of heat and mass transfer in the mixture flow. The local pressure drop, void fraction and heat transfer characteristics have been presented and discussed for different arrangements in detail. The analysis results showed that the overall boiling HTC of the tube arrangements of 30°and 60° appear better for this steam generator under the same condition. The boiling heat transfer in both bottom and upper tube bundle was mainly controlled by the nucleate boiling mechanism. However, both heat flux and vapor void fraction were found to affect the heat transfer performance. Beyond this analysis, a new type of heat transfer correlation has been proposed herein to evaluate the local HTC with a good accuracy. These correlations allow better predictions of the boiling heat transfer inside the SS-SG, which provide designers with better reference and guidance.

Two-Phase Flow-Induced Vibration Among the Horizontal Vver-1000 Steam Generator Tubes

Two-Phase Flow-Induced Vibration Among the Horizontal Vver-1000 Steam Generator Tubes

Simulation of the two-phase flow across tube bundle

Experiments on two-phase flow across an in-line tube bundle are analyzed with the STEG code, which has been developed for modeling thermal-hydraulic processes in a horizontal steam generator (SG). An adiabatic, vertical two-phase flows of air-water across horizontal in-line, 5 x 20 rod bundles, with a pitch-to-diameter ratio P/D=1.3 are considered, the mass velocity is varied in the range 27 - 818 kg/m2s. The calculated values of void fraction in the tube bundle are compared with the experimental ones measured by a gamma densitometer. A reasonable agreement between the calculations and the experimental data is obtained.