On-line Washing Research Articles

How to obtain product green design requirements based on sentiment analysis and topic analysis: Using washing machine online reviews as an example

Green design involves the entire life cycle of a product, including stages such as raw material acquisition, production and manufacturing, sales and transportation, use, recycling, and disposal. Extracting customer requirements (CRs) related to product green design (PGD) is one of the necessary conditions for achieving the dual carbon goal. However, only a few studies have evaluated CRs for PGD from a full life cycle perspective. This study obtained 20,000 online reviews of washing machines from e-commerce platforms. The customers' sentiment tendencies toward the requirements of washing machines at various stages of their life cycle are analyzed and evaluated. The CRs contained in online washing machine reviews were identified through cluster analysis. Based on the life cycle theory, the product green design requirements (PGDRs) of CRs were extracted and analyzed. This study can provide theoretical and methodological support for green product design.

Aerothermodynamic and rotordynamic performance evaluation to diagnose deposits accumulation in a gas lift centrifugal compressor

The paper presents a case study focusing on the assessment of the aerothermodynamic and rotordynamic performance to diagnose deposit accumulation on the internals of a centrifugal compressor. The case involves a four-stage gas lift centrifugal compressor powered by a 5.9 MW induction motor and utilizing a fluid coupling to regulate the compressor's rotational speed. The Huntington 4-point method was employed to evaluate the polytropic head and efficiency of the four compressor sections over a 20-month period, with pressure and temperature data sampled every 6 hours. The efficiency model was supported by the GERG-2008 equation of state, used to calculate the necessary thermodynamic properties at intermediate and endpoint states. The aerothermodynamic analysis identified a deterioration in polytropic efficiency in compressor section 3, accompanied by a pressure drop and an increase in discharge temperature. Simultaneously, the rotordynamic response was examined through various vibration plots. Although the increase in the vibration amplitudes was not significant, a notable phase shift was observed. This decline in polytropic efficiency and change in vibration patterns were attributed to severe fouling, which was confirmed during the overhaul of the HP compressor. Root cause investigations revealed the deposit as reactive, leading to the installation of an online washing system. Over a nine-month observation period post-maintenance, the compressor operation was stable with no degradation in its polytropic efficiency.

Droplets impact against the random rough surface with a liquid film

Aero-engine fouling will affect the economy and safety of aircraft, and online washing is the main method to solve the problem of aero-engine fouling. Online washing is considered to be the removal of fouling particles by the impingement of droplets on a flowing liquid film. Here, we simulate a flowing liquid film of droplets impinging on a randomly rough surface to predict the removal of fouling particles. We considered the situation that the horizontal flow velocity of the liquid film is between 5 and 20 m/s and the thickness of the liquid film is 5–20 μm. An analysis of the droplet impact velocity field, radial velocity, and extension length shows that the vortex strength, radial velocity, and extension length all increase with increasing liquid film flow velocity, while increasing liquid film thickness inhibits the growth. Moreover, we constructed a fouling particle detachment model to evaluate the effects of different liquid film flow velocities and film thicknesses on particle removal. A particle removal plot shows the dominance of liquid film flow velocity stations. This study not only reveals the removal process of fouling particles on random rough surfaces but also provides insight into the optimization of spray cleaning process parameters.

A phenomenological study and comparison of the characteristics of droplet impact liquid film dynamics on randomly rough surfaces

The fouling of aero-engine blades is the main cause of degradation of engine performance and online washing is one of the most effective methods for restoring engine performance. The flow characteristics of the washing fluid after it impinges on the blade surface are critical to the process. The liquid film flow becomes complicated after being impacted by a droplet, because the fouling blade is a random rough surface. The purpose of this study is to evaluate the dynamical characteristics of droplets after they impact the liquid film, focusing on the diameter, the height of the coronal water bloom, and the near-wall flow. We establish a random rough surface to simulate the droplet impacting the liquid film on the fouling surface and analyze the morphological evolution of the corona during the droplet impact process. The results show that an increase in the particle size has a greater impact on the coronal diameter than the coronal height. In addition, a higher droplet impact velocity and thicker liquid film are conducive to the secondary atomization of droplets and improve the transport rate of the cleaning solution. However, the flowability of the liquid film at the impact point is best when the droplet impacts the thin liquid film. Increasing the thickness of the liquid film gradually helps to improve its overall fluidity and results in a better cleaning effect.

Performance Degradation Due to Fouling and Recovery After Washing in a Multistage Test Compressor

Abstract Land-based power units have to fulfill even more high levels of production and reliability. In harsh environments (desert and tropical installations, typically), the power unit ingests high amounts of dust that might deposit inside the compressor. In this paper, the analysis of a multistage compressor performance that operates under sandy and humid conditions has been assessed. The compressor units, which equips the Allison 250 C18 compressor, has been subjected to multiple runs under severe conditions of soil dust ingestion. The compressor has been operated according to subsequent runs, and at the end of each run, the performance curve was recorded; the performance losses, in terms of pressure ratio, have been measured during the operations. The characteristic curve of each run is representative of the level of contamination of the unit. Finally, the compressor has been washed, and the performance curve, in the recovered conditions, has been recorded. The results show the modification and the downward shift of the characteristic curves which lead to a gradual loss of the compressor performance. The curves realized after dust ingestion have been compared with the recovered curve after online washing. The measurement shows a promising recovery of the performances, even if the compressor flow path appears affected by localized deposits able to resist to the droplet removal action. Detailed photographic reports of the inlet guide vane (IGV) and the first compressor stages have been included in this analysis. After each run, the IGV, the rotor blade and stator vane of the first stage, and the hub and the shroud surfaces have been photographed. The pictures show the deposition patterns on the blades and the compressor surfaces. The comparison of the pictures of the internal surfaces, before and after the washing, highlights the parts that are more critical to clean and needy of attention during offline washing and overhaul.

Optimal Design of a UF-RO Treatment System for Shale Gas Fracturing Flowback Wastewater

A membrane-based desalination system under consideration for shale gas fracturing flowback wastewater treatment involves ultrafiltration (UF), reverse osmosis (RO), and storage tanks. The membrane unit (UF, RO) consists of online washing, operation, and offline chemical washing sub-units. These sub-units operate in semi-continuous mode and have the similar characteristics as batch water-using processes. Based on their semi-continuous behaviors, the models of UF and RO sub-units are developed. The objective is to maximize the total water production ratio and profit while minimizing storage tank capacity. Three nonlinear programming optimization models are developed for an optimal design of the UF-RO treatment system for shale gas fracturing flowback wastewater. Two scenarios, fixed schedule and fixed operating period, for UF/RO treatment sub-units are investigated. Results show that with the increasing of the operation duration of treatment sub-units, the water production ratio and profit will increase. The schedule of treatment sub-units has significant impact on the water storage profiles, without adversely affecting the water production ratio. The proposed approach can guide the design of the UF-RO desalination system.

Reagent approach for silicate deposits prevention in waste heat boilers

New reagent composition with optimal phosphate:thermal polymer ratio has been developed and studied for steam-and-condensate channel protection and its corrosion prevention as well as for on-line washing to remove old silicate deposits formations. Optimal dosage and water-chemistry conditions for a medium pressure steam boiler with specified quality of feed water have been selected. The causes of silicate deposits in medium pressure waste-heat boiler have been analyzed. The reagent efficiency has been evaluated while industrial applications.

Study on the Mechanism of a Carrier-based Engine Parts' Performance Decline and Its Impact on the Whole Engine Performance

The technical approach "use – parts' change - engine performance change" has been adopted to study and analyse the gas unit parts' performance changes of an engine after a long time operation. The mechanism of performance decline of the turbine is analysed based on the numerical simulation, the impact of components' performance decline on overall engine performance is studied and the correlation analysis is carried out. The results show that the change of turbine tip clearance, roughness increase and surface change will lead to the enhancement of secondary flow and the increase of influence area, and the turbulence effect is strengthened, resulting in the decrease of turbine circulation capacity and efficiency. The booster ratio of high pressure compressor, the flow capacity of high pressure and low pressure turbines, the flow capacity and efficiency of fan are the major component parameters causing the overall engine performance's degradation. And it also provides theoretical basis for the prevention of engine performance's degradation and online washing of parts and the whole machine.

Application of a simple column-switching ion chromatography technique for removal of matrix interferences and sensitive fluorescence determination of acidic compounds (pharmaceutical drugs) in complex samples

This work illustrates the introduction of a simple, rugged and flexible column-switching ion chromatography (IC) technique for an automated on-line QuEChERS extracted samples extracts washing followed by sensitive fluorescence (FLD) determination of five acidic pharmaceutical drugs namely; clofibric acid (CLO), ibuprofen (IBU), aspirin (ASP), naproxen (NAP) and flurobrofen (FLU) in three complex samples (spinach, apple and hospital sewage sludge). An old anion exchange column IonPac® AS11-HC was utilized as a pre-treatment column for on-line washing of inorganic and organic interferences followed by isocratic separation of five acidic drugs with another anion exchange IonPac® AS12A analytical column by exploiting the column-switching technique. This novel method exhibited good linearity with correlation coefficients (r2) for all drugs were in the range 0.976–0.996. The limit of detection and quantification of all five acidic drugs were in the range 0.024μg/kg to 8.70μg/kg and 0.082μg/kg to 0.029mg/kg, respectively, and better recoveries in the range 81.17–112.5% with percentage relative standard deviations (RSDs) less than 17.8% were obtained. This on-line sample pre-treatment method showed minimum matrix effect in the range of 0.87–1.25 except for aspirin. This simple rugged and flexible column-switching system required only 28min for maximum elimination of matrices and interferences in three complex samples extracts, isocratic separation of five acidic drugs and for the continuous regeneration of pre-treatment column prior to every subsequent analysis. Finally, this simple automated IC system was appeared so rugged and flexible, which can eliminate and wash out most of interference, impurities and matrices in complex samples, simply by adjusting the NaOH and acetonitrile concentration in washing mobile phase with maximum recoveries of acidic analytes of interest.

Design of Online Washing Process for an Engine Based on Washing Experiments

In order to develop online washing process of a carrier-based aircraft engine and improve washing efficiency, washing equipments were employed in cold operation state to carry out experimental study on structural strength of spray frame, selection of nozzle and determination of injection parameters of online washing spray system, determination of washing injection timing, determination of drying procedure, liquid-washing experiments of different concentrations and water-washing experiments and so on. The results show that if engine is washed in cold operation state, mid-nozzle with upward offset angel of 7°30′ can be selected and the feed liquid pressure provided by washing vehicle is 0.9Mpa. The start time is 20s after an engine cold start-up, and sustains 30s for once washing. After a liquid-washing with the use of washing fluid, the liquid concentration of which is no more than 20%, twice water-washing can be carried out to rinse the almost all cleaning agent remaining in the engine runner(the residue is less than 1%). The engine can be thoroughly dried by power-on operation, the procedure of which is engine operating 2min in ideal state, then 2min in state of n2=85% and 2min of ideal state lastly. Washing will not affect the engine function.

Industrial Gas Turbine Health and Performance Assessment With Field Data

The paper presents a thorough analysis of the historical data and results acquired over a period of two years through an on-line real-time monitoring system installed at a combined heat and power (CHP) plant. For gas turbine health and performance assessment, a gas path analysis tool based on the adaptive modeling method is integrated into the system. An engine adapted model built through a semi-automated method is part of a procedure which includes a steam/water cycle simulation module and an economic module used for power plant performance and economic assessment. The adaptive modeling diagnostic method allowed for accurate health assessment during base and part load operation identifying and quantifying compressor recoverable deterioration and the root cause of an engine performance shift. Next, the performance and economic assessment procedure was applied for quantifying the economic benefit accrued by implementing daily on-line washing and for evaluating the financial gains if the off-line washings time intervals are optimized based on actual engine performance deterioration rates. The results demonstrate that this approach allows continuous health and performance monitoring at full and part load operation enhancing decision making capabilities and adding to the information that can be acquired through traditional analysis methods based on heat balance and base load correction curves.

Evaluating Gas Turbine Performance Using Machine-Generated Data: Quantifying Degradation and Impacts of Compressor Washing

Gas turbine (GT) operators are often met with the challenge of utilizing and making meaning of the vast measurement data collected from machine sensors during operation. This can easily be about 576 × 106 data points of gas path measurements for one machine in a base load operation in a year, if the width of the data is 20 columns of measured and calculated parameters. This study focuses on the utilization of large data in the context of quantifying the degradation that is mostly related to compressor fouling, in addition to investigations on the impact of offline and online compressor washing. To achieve this, four GT engines operating for about 3.5 years with 51 offline washes and 1184 occasions of online washes were examined. This investigation includes different wash frequencies, liquid concentrations, and one engine operation without online washing (only offline). This study has involved correcting measurement data not only just with compressor inlet temperatures (CITs) and pressures but also with relative humidity (RH). turbomatch, an in-house GT performance simulation software has been implemented to obtain nondimensional factors for the corrections. All of the data visualization and analysis have been conducted using tableau analytics software, which facilitates the investigation of global and local events within an operation. The concept of using of handles and filters is proposed in this study, and it demonstrates the level of insight to the data and forms the basis of the outcomes obtained. This work shows that during operation, the engine performance is mostly deteriorating, though to varying degrees. Online washing also showed an influence on this, reducing the average degradation rate each hour by half, when compared to the engine operating only with offline washing. Hourly marginal improvements were also observed with an increased average wash frequency of nine hours and a similar outcome obtained when the washing solution is 2.3 times more concentrated. Clear benefits of offline washes are also presented, alongside the typically obtainable values of increased power output after a wash, also in relation to the number of operating hours before a wash.

Reliability evaluation of a Gas Turbine Water Wash System – A case study

In this article, a reliability analysis was carried out on a Gas Turbine Water Wash System used for washing the compressors of three (3) GE Frame 7 EA Gas Turbines using Weibull Distribution. Note that availability of this system is crucial to recovering compressor efficiency and by extension generation capability that has been lost due to contaminants on the compressor blades. This system therefore, helps maintain and improve the reliability of the turbine and of plant-wide generation. The reliability analysis covered two failure modes for each piece of equipment and took into account the reliability of the system in two operational modes, off-line washing cycle and online washing cycle for a 300 h operational time. Based on the results obtained it can be concluded that the entire water wash system can be taken as 76% reliable based on a 300 h running time. It is more reliable to perform an online water wash than an off-line water wash by at least 4% based on a 300 h operating time. This increased reliability of the water wash system to perform an online water wash is due to an off-line water wash requiring additional equipment which must be run in series.In addition to the aforementioned analysis fault trees were created to model two scenarios which relate directly to the efficiency of the gas turbine compressors and the generation capability of the turbine: (1) the likelihood of no water being present when conducting a water wash; and (2) the likelihood of cold water being sent to the water wash manifold. Based on the estimated reliabilities, the likelihood of no water being present when conducting a water wash was found to be 3.7% and the likelihood of cold water being sent to the water wash manifold is 1.6%.

The Development and the Field Application of the On-Line Dry Ice Washing Vehicle System

Abstract: In order to wash the polluted substation insulator quickly and safely, so as to improve the reliability of substation systems, an on-line dry ice washing system which would be applied in 220 kV voltage level was developed. Based on the results of the indoor simulation tests which provided the optimal washing parameters, the on-line dry ice system was developed. Moreover, a trial test was run in a 220 kV substation belonging to Hubei State Grid. The test results show that the vehicle system can meet the requirements of on-line washing tasks in 220 kV substation. Therefore, the washing system features advanced technology, excellent performance, and promotional value.

Industrial Gas Turbine Performance: Compressor Fouling and On-Line Washing

Industrial gas turbines are susceptible to compressor fouling, which is the deposition and accretion of airborne particles or contaminants on the compressor blades. This paper demonstrates the blade aerodynamic effects of fouling through experimental compressor cascade tests and the accompanied engine performance degradation using turbomatch, an in-house gas turbine performance software. Similarly, on-line compressor washing is implemented taking into account typical operating conditions comparable with industry high pressure washing. The fouling study shows the changes in the individual stage maps of the compressor in this condition, the impact of degradation during part-load, influence of control variables, and the identification of key parameters to ascertain fouling levels. Applying demineralized water for 10 min, with a liquid-to-air ratio of 0.2%, the aerodynamic performance of the blade is shown to improve, however most of the cleaning effect occurred in the first 5 min. The most effectively washed part of the blade was the pressure side, in which most of the particles deposited during the accelerated fouling. The simulation of fouled and washed engine conditions indicates 30% recovery of the lost power due to washing.

Multiphase flow modeling and optimization for online wash systems of gas turbines

Compressor blade fouling in gas turbines could lead to significant loss in power and efficiency. Online wash systems are used to remove fouling without having to shut down the gas turbine. Hence, the design of efficient online wash systems could lead to significant recovery of performance. The present study aims at developing a generalized numerical approach for the optimization of online wash systems for gas turbines. The procedure utilizes a Lagrangian particle-tracking multiphase flow model combined with constrained multi-objective optimization to develop design charts for selecting the optimal nozzle diameter, location, mass flow rate and half-cone angle. The developed approach is used to optimize the design of the online wash system for the General Electric MS5002 gas turbine model. Comparisons and differences between the optimized design and the existing design are highlighted and presented.

Simultaneous oxytocin and arg-vasopressin measurements in microdialysates using capillary liquid chromatography–mass spectrometry

Oxytocin (OXT) and arg-vasopressin (AVP) are nonapeptides with many important functions both peripherally and centrally. Intracerebral microdialysis has helped characterize their importance in regulating complex social and emotional processes. Radioiummunoassay is the most commonly used analytical method used for OXT and AVP measurements in microdialysates. These measurements have several well-known issues including single peptide per assay limit, possible cross-reactivity between structurally related peptides, and laborious sample preparation with radioactive materials. Here we demonstrate the use of capillary LC–MS3 for measuring OXT and AVP simultaneously in dialysates at a 10min sampling frequency. Microdialysate samples required no preparation and instrumentation was commercially available. Microdialysis probes made with polyacrylonitrile membranes were suitable for high level recovery of the peptides in vitro and in vivo. Responses were linear from 1 to 100pM. Matrix effect was assessed by standard addition experiments and by comparing signal intensities of OXT and AVP standards made in aCSF or dialysate. It was determined that the online washing step used on this setup was adequate for removing contaminants which interfere with electrospray ionization efficiency. In vivo, both peptides were stimulated by high K+ (75mM) aCSF perfusion in the paraventricular nucleus (PVN). Also, a systemic injection of high Na+ (2M) caused a rapid and transient increase in PVN OXT while AVP increased only after 1.5h. Our findings suggest that capillary LC–MS3 is a straightforward method for monitoring OXT and AVP simultaneously from complex samples such as dialysates.

Predicting Compressor of Gas Turbine Power Plant On-Line Washing Interval Using Proportional Hazards Model

Due to compressor fouling, gas turbine efficiency decreases over time, resulting in decreased power output of the plant. To counteract the effects of compressor fouling, compressor on-line and off-line washing procedures are used. The present research is aimed to propose a method of mathematical modeling of offline washing interval which will be estimated as the RUL of compressor based on Proportional hazards model. Application of the proposed prediction method to the case of Civil Aero-engine proved its effectiveness.

Predicting Compressor of Gas Turbine Power Plant On-Line Washing Interval Using Proportional Hazards Model

Predicting Compressor of Gas Turbine Power Plant On-Line Washing Interval Using Proportional Hazards Model

Compressor performance recovery system: which solution and when

During normal operation, compressor is mainly affected by fouling due to air pollution, which causes its performance to degrade over time. The main solutions to reduce compressor fouling are off-line compressor washing, on-line compressor washing, and advanced air filtration systems. Overall, the choice of the best recovery system for each gas turbine in the specific power plant is not trivial. The aim of this study is to provide a guide to identify the best washing or filter devices for a gas turbine (GT) in a specific power plant site, using literature information and GT users data. Two procedures were conceived in order to have an user-friendly tool. ‘Best cleaning device’ was developed to help a GT user in the choice of the best devices for recovering compressor performance. Gathering information about GT performance and environmental conditions from real applicatios and literatures, a value of recommendation for each technology is provided. ‘Best cleaning time’ is based on the thermoeconomics theory of ‘best maintenance time’ and it provides the user an estimation about the best time to perform a compressor off-line or on-line washing. Both procedures have been proved on a few real cases, showing good results and indications to more in-depth development.