Gas Pumping Research Articles

Перспективы применения российских абсорбционных термотрансформаторов на ПГУ-ТЭЦ

The electrical power of power plants based on gas turbines (GT) decreases with an increase in air temperature and, as a result, a decrease in its mass flow at the compressor inlet. This makes it relevant to develop methods for increasing air density by lowering its temperature when wor¬king in hot arid regions and regions with a tropical humid climate. To cool the air, it is proposed to use absorption chillers (LBAC). It is shown that for air cooling in a dry hot climate, it is sufficient to use LBAC with single-stage absorption. For a humid tropical climate, where deeper air cooling is required with a simultaneous decrease in its moisture content, it is proposed to use ABCM with two-stage absorption, which are capable of producing cold at negative temperatures. To do this, it is proposed to introduce an additional evaporation and absorption unit with peri¬pheral equipment into the standard industrial design of the LBAC with single-stage absorption. Comparative energy efficiency of LBAC of standard design and LBAC with two-stage absorption during air cooling at the GT compressor inlet has been evaluated. For such critical facilities for the Russian economy as gas pumping stations using gas turbines, an LBAC unit with two-stage absorption and removal of absorption heat by water-circulating cooling systems based on cooling towers, or using air coolers (drycoolers) with the ability to turn off an additional evaporation unit if necessary, is proposed. and absorption.

A VALUE STREAM MAPPING IN ADVANCED MANAGEMENT SYSTEMS

All efforts in advanced management systems should maximize value for the customer. One effective way to identify and realize this value is to map the product's flow from end customer to a supplier by visualizing the value streams of individual processes. This paper aims to analyse and propose the introduction of a lean value stream in vacuum pump assembly to achieve increased production output. Vacuum technology is the field of engineering concerned with creating and using a vacuum. It, therefore, deals with an environment in which the gas pressure is lower than the atmospheric pressure. A vacuum pump is a gas pump that extracts air from an enclosed space to create a vacuum. The basic parameters are the vacuum level achieved and the pumping speed. Several design solutions are available that meet the aforementioned basic parameters. A turbomolecular pump was selected for this study. The incentive to improve the material and information flow on the vacuum pump assembly line is the significant increase in orders from the customer. The technique used is production value stream mapping. Following the output of the Value Stream Mapping (VSM), a change plan is determined to optimize the assembly process, which will positively influence the future state of the value stream to meet the customer's requirements.

Visible to Mid-Infrared Supercontinuum Initiated by Stimulated Raman Scattering of 1.03 μm Ultrashort Pulses in a Gas-Filled Silica Fiber

Multiband supercontinuum generation covering the bandwidth from 0.65 μm to 3.3 μm was demonstrated in a gas-filled hollow-core silica fiber pumped by chirped ultrashort pulses at 1.03 μm. The development of the SC spectrum into the mid-IR was initiated by cascade stimulated Raman scattering in gaseous D2, which was used as an active medium filling the hollow core. The influence of the Kerr nonlinearity was studied by changing the linear chirp of the pump pulses. The influence of gas pressure and pump pulse energy on the SC generation was investigated. As high as 14% of pump quanta were converted to the wavelength range above 2 μm.

Predictive state analytics of gas pumping units

Diagnostics of the technical condition of equipment is an important factor in the efficiency of any production. This fully applies to the oil and gas industry with its huge fleet of pumping and compressor equipment, the downtime and repair of which, as a result of any accidents, causes significant damage to enterprises. The development of digital technologies, such as Big Data, IIoT, and machine learning makes it possible to move on to the so-called predictive or predictive analytics, which makes it possible, based on the analysis of trends in a large number of variables, in real time to predict the possible onset of an emergency. The article considers the possibility of building a local system of predictive analytics for a gas compressor unit based on the analysis of its behavior before the accident, during the accident and after it. The predictive analytics system (PSA) was built based on the real data of the unit, on which surge occurred due to fatigue failure of the high-pressure compressor elements. The evaluation of the resulting model showed its high accuracy even under conditions of a limited set of initial data. The use of such systems makes it possible to avoid accidents that occur as a result of a change in the technical condition of the equipment and are absent, in connection with this, in emergency protection scenarios.

PRINCIPLES OF OPTIMIZING CONTROL OF GAS TRANSPORTATION SYSTEMS UNDER CONDITIONS OF THEIR UNDERLOAD

The work is devoted to establishing the regularities of the flow of technological processes in gas transportation systems to optimize the operational management of operating modes under the condition of their incomplete loading. On the basis of the study of the stationary modes of operation of the gas transportation system with changes in the volume of gas pumping, the principle of building a mathematical model based on the superposition of the characteristics of linear sections and compressor stations is proposed, which makes it possible to estimate the throughput of the system, parameters of the operating mode, and energy consumption for gas transportation. The methods of building a system of integral influence coefficients for gas transportation systems in order to evaluate the parameters of its operation in stationary modes of operation are presented. Each change in the technological parameters of the operating mode at the entrance of the gas transport system will necessarily cause a reaction of the system, which will manifest itself in a change of the corresponding parameters at its exit. It is obvious that the input and output parameters of the system are interconnected by a complex system of equations, the implementation of which requires certain time costs and the collection of additional information about the technical and hydro-gas-dynamic conditions of the system at each moment of time. In the conditions of incomplete loading of the gas transportation system, which involves frequent changes in its operation modes, the implementation of the task is not always possible. It is proposed to create a system of integral influence coefficients that characterize the ratio of input and output information in various stationary modes and to formally present it in a matrix form. On the basis of the research results, the principle of optimizing the operation modes of the gas transportation system under conditions of partial loading according to the criterion of minimum energy consumption for gas transportation at the maximum level of gas supply reliability is proposed.

Direct numerical simulation of a transitional, cryogenic cavitating mixing layer of liquefied natural gas behind a flat splitter plate using a homogenous equilibrium mixture cavitation model

A major challenge in the design of liquefied natural gas (LNG) pumps is concerned with the accurate prediction of flow behaviour at off-design conditions where destructive phase change from liquid to vapor - named cavitation - at cryogenic conditions may emerge undesirably and downgrade the machine performance. As a first step of our research towards addressing this challenge, the present study employs a homogenous equilibrium mixture (HEM) –based cryogenic cavitation solver to run direct numerical simulation (DNS) of a fundamental case study of transitional cavitating mixing layer of LNG behind a 3D planar flat plate, which resembles actual conditions of flow behind the vanes of industrial LNG sub-merged pumps. Assessment of the preliminary findings shows that the mixing layer is mainly driven by different modes of the well-known Kelvin-Helmholtz (K–H) instabilities, which develop coherent vortex structures that tend to shed off periodically across the mixing layer. The cavity structures are formed via transient interactions of the shedding vortices, and in the meantime of their pairing processes. The shedding of cavities, which mostly appear as “horse-shoe” and “croissant”-shaped vapor structures, maintains by the unsteady sheet cavity formed on the splitter upper wall and the latent heat exchange mechanisms, beside the dominant K–H instabilities. The presence of three-dimensionality is found to enhance instability of the mixing layer by increasing the frequency of phase change successions.

Calculation of the deflection of the blade of the disk of an axial gas pumping machine

The mechanism of occurrence of errors leading to failure of parts of compressors and pumps is investigated. A method is proposed for non-destructive control of the accuracy of manufacturing of non-rigid parts with end surfaces of revolution without reducing productivity. Keywords: compressor, non-rigid part, technological system, diagnostics. nga112001@list.ru

Temporal behavior of the high-power pulsed gas terahertz laser pumped by a fundamental mode TEA CO2 laser.

Optically pumped gas molecular terahertz (THz) lasers are promising for generating high-power and high-beam-quality coherent THz radiation. However, for pulsed gas THz lasers, the temporal behavior of the output THz pulse has rarely been investigated. In this study, the temporal behavior of a pulsed gas THz pumped by a fundamental-mode TEA CO2 laser has been presented for the first time both in simulation and experiment. A modified laser kinetics model based on the density matrix rate equation was used to simulate the temporal behavior and output pulse energy of a pulsed gas THz laser at different gas pressures. The results clearly show that the working gas pressure and pump pulse energy have critical influences on the output THz pulse shape. Three typical pulse shapes were obtained, and the THz pulse splitting caused by gain switching was quantitatively simulated and explained based on the laser dynamic process. Besides, with an incident pump pulse energy of 342 mJ, the maximum output THz pulse energy of 2.31 mJ was obtained at 385 µm, which corresponds to a photon conversion efficiency of approximately 56.1%, and to our knowledge, this is the highest efficiency for D2O gas THz laser. The experimental results agreed well with those of the numerical simulation for the entire working gas pressure range, indicating that our model is a powerful tool and paves the way for designing and optimizing high-power pulsed gas lasers.

Application of Industrial Internet of Things (IIoT) in Crude Oil Production Optimization Using Pump Efficiency Control

The collapse of oil prices in mid-2014 and early 2016 was the biggest in modern history that witnessed more than a 70% drop in the price to around $40 barrel. It prompted companies to think seriously to maintain profitability. Most companies were able to survive partly by simplifying their operations. Price recovery in 2021 is only 70% of its peak value. Companies are focusing on reducing the cost of operations, increasing production simultaneously, and finding new and different strategies to survive. The current scenario is witnessing strong research focusing on the development of process control for oil and gas upstream and downstream to improve the control and preventive maintenance to reduce operating costs and increase production. This paper presents the Industrial Internet of Things (IIoT) practical solution that improves the oil production rate from the well and increases the average pump efficiency (fillage) to 90%. This paper proposes a mechanism for collecting, storing, and analyzing all required parameters to build valuable charts. These charts’ data help optimize the values and parameters for controller setpoints to prevent pump gas lock problems. An artificial lift is required to lift the oil from the well. In this paper, the sucker rod pump is driven by a gas engine fed by the well’s gas. At the same time, SCADAPack 535E remote terminal unit collects all pump and well parameters such as hydraulic pressure, casing pressure, tubing pressure, and pump speed in stroke per minute (SPM). The remote terminal unit sends the data through a wireless network using a 5 GHz antenna to the main control room. The IIoT platform is designed using a visual basic programming language. Microsoft DDE (Dynamic Data Exchange) and Kepware OPC server were used to work on the received data to monitor, generate charts, and apply the controllers.

Experimental research on dynamic characteristics and control strategy of the pump-driven two-phase loop with dual evaporators

The pump-driven two-phase loop is a promising thermal management technology for avionics, but its dynamic characteristics and control strategy are not clear. A prototype of a pump-driven two-phase loop with a single/dual evaporator for cooling of avionics was developed and its dynamic characteristic under different heat loads and flow rates were studied. It was found that after the evaporator outlet reached saturation, increasing the flow rate would instead reduce the performance, due to the increasing flow resistance of the gas tube and pump power consumption. Based on this, a control strategy of controlling the vapor quality at the evaporator outlet to 0.9–0.95, by adjusting the speed of the pump, was proposed and verified under dynamic heat loads. The results showed that this control strategy ensured optimal system heat transfer performance while reduced the power consumption of the pump. In the experiments of the pump-driven two-phase loop with dual evaporators, it was found that the branch with the larger heat load had a lower flow rate, and was more likely to be superheated. Therefore, in the control of a pump-driven two-phase loop with multiple evaporators, the branch with the maximum heat load should be taken as the control object.

Dynamic behavior of solar thermochemical reactors for fuel generation: Modeling and control strategies

Solar thermochemical water splitting provides an efficient route for converting solar energy into renewable fuels. The operation of solar thermochemical reactor under real on-sun condition requires in-depth understanding of its dynamic behaivor under fluctuating direct normal irradiation (DNI). In this work, we developed a 2D axial-symmetric multi-physical model to assess the reactor’s dynamic behavior with three oxygen removing technologies electrochemical oxygen pump (EOP), sweep gas (SG), and vacuum pump (VP), under varying solar irradiations. To alleviate the negative effect of decreased DNI, two control strategies (CS) including varying operational conditions for oxygen removing technologies (CS1) and replacing the reduction step with the oxidation step (CS2) were conducted. We found that CS1 was only effective when DNI reduction was larger than 75 % over the whole reduction step (case 2). In general, CS2 can be implemented to alleviate the efficiency decrease for all DNI variations expect for the case 2 in this study. Especially, CS2 significantly increased the solar-to-fuel efficiency compared to the case without control strategy for the reduced DNI from 1000 W/m2 to 500 W/m2 during the whole reduction step. The reactor dynamic behavior in response to the daily DNI variations is also reported which shows that the efficiency profiles are highly in line with the DNI profile. This modeling work as well as proposed control strategies can be used to guide the design and control of solar thermochemical reactors under realistic conditions and hence for better assessing the performance of the reactor in practice.

Determination of organic impurities by plasma electron spectroscopy in nonlocal plasma at intermediate and high pressures

This study aims to improve impurity analysis by plasma electron spectroscopy for organic molecules. Various impurities can be registered simultaneously in one measurement, because the appearance energies of the characteristic Penning electrons vary for different chemical compounds. Herein, experimental studies were conducted on helium with alcohol vapor impurities in a nonlocal negative glow plasma of a short glow micro-discharge with an increase in pressure from 15 Torr to 150 Torr. As a result, plasma electron spectroscopy enables the detection of gas impurities in high-pressure (even at atmospheric) environments, which eliminates the need for expensive and cumbersome gas pumping systems and expands the scope of the method.

Конструктивные особенности лопастных решеток рабочих колес, перекачивающих газожидкостные смеси, позволяющие снизить объем газовых каверн

We employed numerical simulation methods to investigate how design features of impeller vane cascades in a centrifugal pump processing gas and liquid mixtures will affect the magnitude of gas caverns. We derived a mathematical model for multiphase flow of incompressible fluid. We performed hydrodynamic computations for various impeller vane cascade designs. We identified regions of local gas separation in commercially available and improved cascades that may result in gas plug formation and pump failure. The paper investigates the effect of the following parameters on the magnitude of a gas cavern: the angle of attack, pressure feed, pressure gradient, and the presence of through holes and transverse cutouts in a single-tier vane cascade. We consider design features of stacked van cascades and investigate how the vane length and vane distribution uniformity in the blading section of a stacked vane system affect gas cavern magnitudes. We selected the optimum vane cascade design for multiphase impellers. The paper then indicates further lines of research.

Disclosing the heat density of district heating in Austria in 2050 under the remaining European CO2 budget of the 1.5 °C climate target

The core objective of this work is to downscale the cost-effective heat supply of different European decarbonization scenarios generated by the aggregate model GENeSYS-MOD from the national to the community level in Austria and thus disclose the heat density of district heating in 2050. We assume that district heating encompasses geothermal, synthetic gas, hydrogen, waste, and large-scale heat pumps as renewable heat sources. The results determine district heating in 68 Austrian communities in Austria in 2050, which corresponds to 6% of the total number of communities. We find that GENeSYS-MOD results are capable in covering local trends in district heating since high shares of the projected heat densities at the local levels achieve values indicating economic viability. Further research should follow on how locally determined district heating and heat densities could be returned into more aggregate models, such as GENeSYS-MOD, in the sense of a feedback loop. That allows refining assumptions in the large-scale upper-level models, which in turn will increase the plausibility and realism of pathways at the European level.

Numerical design of self-pumped electrostatic precipitators for particle collection

Electrostatic precipitators (ESPs) have been widely used to remove particles from gas. However, an additional gas pumping system should be utilized to pump the particle-laden gas. A self-pumped ESP is proposed, in which the ESP itself pumps particle-laden gas. The gas flow and particle collection characteristics are evaluated numerically. Results demonstrate that a nearly unidirectional ion wind stream can be generated with a suitable arrangement of electrodes. Particles significantly restrain the corona discharge current and decelerate the gas accordingly. Particles with a smaller diameter and a higher concentration exert a more significant influence on the corona discharge and gas flow. The average velocity of 0.5 m/s at the inlet of the ESP (area of 0.3 m2) is achievable with a voltage of 23 kV and a power consumption of 20 W. A collection efficiency of more than 99 % is achievable for particles with a diameter of 5 µm.

Operational Performance Analysis of the Cryogenic Electrical Machine for Submerged Liquefied Natural Gas Pumps

The electrical machine is one of the key components for submerged liquefied natural gas (LNG) pumps. This study deals with a cryogenic permanent magnet synchronous motor (CPMSM) for submerged LNG pumps. An 18.5-kW CPMSM prototype was developed according to the needs of users. The basic design of the CPMSM was proposed by using a cryogenic temperature (CT) design method. To analyze the operational performance accurately, simulation modeling and analysis are carried out, and a liquid nitrogen (−196°C) experimental platform is built. The test results verify the rationality of the design and the accuracy of the simulation. Based on the simulation and experimental data, the working characteristics and mechanical properties of the prototype in liquid nitrogen are analyzed. In addition, the performance of the prototype operating in liquid nitrogen (−196°C) and LNG (−161°C) are compared and analyzed, and the results show that the operating characteristics of the prototype in the two fluid environments are similar.

Energy, emissions, economic analysis of air-source heat pump with radiant heating system in hot-summer and cold-winter zone in China

The energy savings and economic performance study of the air-source heat pump (ASHP) and wall-hanging gas boiler (WGB) heating systems in hot-summer and cold-winter (HSCW) zones of China is beneficial to the development and implementation of relevant policies under the carbon neutrality background. This research presented a comprehensive analysis of the heat load, primary energy consumption, carbon dioxide and other emissions, and running costs of both heating systems in HSCW zones. Theoretical mathematical models of the energy consumption, emission, and economic performance of the ASHP and WGB heating systems were developed. The calculation results showed that the ASHP system consumed 12.3 % less primary energy than the WGB system, emitted 36.9 % more carbon dioxide, and reduced running costs by 26.0 %, where the increase in carbon dioxide emissions was mainly due to the limited heat-to-electricity conversion efficiency of grid systems. The experimental results showed the excellent energy consumption saving and economic benefits of the ASHP system compared to the WGB system, which promoted the applications of ASHP on a larger scale in HSCW zones of China. The comprehensive research results on the energy-saving and carbon dioxide emission performance of ASHP and WGB can contribute to evaluating the necessity of replacing WGB with ASHP and provide references for relevant policy planning in HSCW zones in China. The replacement of WGB with ASHP for spacing heating systems is promising coupled with the power system reformation to reduce carbon dioxide emissions and accomplish China's carbon neutrality target.

Predictive modeling of the deuterium gas puffing effect on impurity and heat flux compression for the HL-2M divertor by SOLPS

To study the effect of gas puffing on divertor operation regime and impurity level in the SOL region, we introduce deuterium gas puffing and pumping, based on the HL-2M lower single null (LSN) divertor configuration (Ip=2MA), using the SOLPS5.0 code. The simulation result indicates that the location of the gas puffing port impacts the divertor plasma condition, and puffing deuterium from the location near the divertor region can enhance the power dissipation and the divertor regime transformation from high recycling region to detachment. Besides, increasing deuterium gas puffing rate can strengthen the core confinement. Meanwhile, the impurity level in the SOL region is compressed rapidly, from Zeff=2.0 to 1.1, with a reasonable deuterium gas puffing rate of 2.5×1022s−1 puffed from the optimized port and a constant chemical sputtering yield Ychem of 1.0%, compared to the case with no gas puffing. The physics interpretation behind this phenomenon is also analyzed. It is demonstrated that the ionization rate distribution and the carbon ions’ poloidal velocity define the impurity flow in the SOL region. The higher ionized carbon ions (C4+ to C6+) retain in the ionization region and even flow downstream when they finish ionization before reaching the stagnation point with gas puffing. Then the impurity ions accumulate in the divertor region. The balance between the thermal and friction forces acting on the carbon ions results in the change of poloidal velocity. In general, deuterium gas puffing and pumping induces the modification of impurity flow and the decline of the Zeff. Furthermore, a chemical sputtering yield of 3.0% is also calculated to verify the efficiency of deuterium gas puffing on Zeff compression.

Energy optimization of wet air oxidation reactors with sub-millimeter bubble intensification

The huge investment in equipment and energy consumption required for wet air oxidation (WAO) severely limits its industrial application due to harsh operating conditions with high temperatures and pressures. In this work, the energy consumption of phenol WAO was calculated considering gas compression, pumping, preheating and bubble generation. The relationship between energy consumption, bubble diameter and phenol conversion was constructed to evaluate the main influencing factors. It was found that sub-millimeter bubbles can effectively improve the WAO process by enhancing the oxygen mass transfer, resulting in a decrease in operating temperature and pressure. Considering the maximum conversion and minimum cost, the initial air bubble diameter for phenolic WAO is preferably between 0.2 ∼ 0.4 mm. The model was validated using experiments with a WAO reactor dominated by sub-millimeter air bubble, and good agreement was obtained between simulated results and plant data.

Impact of sector-coupling in microgrid to residual electricity demand properties

This paper discusses how the contribution of microgrid (MG) introduction to the power grid depends on sector coupling. MG is designed to suppress the residual demand from the grid and its variation, under the cost constraint. In this paper, three levels of sector coupling are considered for electricity, heat, and hydrogen demand. In Lv.1, the MG supplies only electricity to the demand. The MG is equipped with photovoltaic (PV) and storage battery. In Lv.2, the MG equipped with PV, storage battery, heat pump, chiller, thermal tank, and hydrogen gas boiler to supply both electricity and heat to demand. For heat delivery, heat pipeline network is laid and used. In Lv.3, all electricity, heat, and hydrogen supplies are coupled at MG. From the obtained results, it is ascertained that the higher sector coupling can realize the higher flexibility in residual demand.