Regulator Valve Research Articles

Energy-efficiency-oriented optimal control for electrical environmental control system based on advanced neural network

Electric environmental control system (EECS) adopts the unique architecture of electric compressor bleed air and multi-stage expansion refrigeration. The state of EECS is regulated by the electric compressor and multiple regulation valves together, resulting in flow and temperature of each node strongly coupled. Traditional methods use a single valve to control each objective without considering the effect of control scheme on energy efficiency, which will not only lead to poor control effect, but also limit the coefficient of performance (COP) of EECS. This paper proposes an energy-efficiency-oriented optimal control strategy to improve the COP and control performance simultaneously. Part of the regulation valves are regarded as optimization variables and the corresponding control objectives are regarded as constraints to maximize COP. On this basis, an advanced control algorithm is proposed to further improve the control effect. The COP prediction model is developed with an offline trained neural network and the optimal valve openings are solved by the differential evolution algorithm. The controller is developed with another neural network online trained by adaptive learning rate algorithm to adapt to complex conditions. The results show that the COP and control performance of EECS are significantly improved. Compared to other strategies, the optimal control strategy can increase COP by up to 61.14%. This study provides an effective solution to the optimal control problem of systems with similar structure to EECS.

Flow characteristics and flow rate prediction of pulverized coal through a regulation valve

• The optimum valve sweeping gas fraction was determined. • Control characteristics of the regulation valve were studied. • Limit operating conditions of the regulation valve were defined. • A semi-empirical model was established for pulverized coal flow rate prediction. In this paper, experiments of dense-phase pneumatic conveying of pulverized coal were carried out in an industrial-scale system to study the control characteristics of the regulation valve and to predict the solid mass flow rate. Firstly, effects of valve sweeping gas on conveying stability and solid mass flow rate were investigated and the optimum valve sweeping gas was determined. Second, effects of valve opening on pressure distribution and solid mass flow rate were investigated by conducting experiments at different conveying pressure drops and different valve openings. A good linear relationship between the valve pressure drop ratio and the valve opening was found, and as the valve opening increased from 13 % to 70 % the solid mass flow rate increased gradually. Limit operating conditions of the regulation valve including flow blockage and control failure were consequently determined and analyzed. Finally, a robust model was established to predict the solid mass flow rate by introducing the valve sensitivity coefficient into the traditional pressure drop ratio model. The model can predict the solid mass flow rate well by providing errors mostly within ± 10 %. This study will provide certain reference for solid mass flow rate regulation in the dry coal gasification process.

Tracer Gas Test and CFD Analysis of Semiconductor Gas Box for Flammable Gas Leakage

Semiconductor manufacturing is performed through unit processes that use various chemicals and facilities. In particular, flammable gases, such as H2, NH3, and CH4, are used, and there is a risk of explosion when such gases leak. In this study, computational fluid dynamics (CFD) simulation and a “tracer gas test” according to the SEMI (Semiconductor Equipment and Materials International) S6 Environmental, Health, and Safety Guideline for Exhaust Ventilation of Semiconductor Manufacturing Equipment specification were performed during the leakage of hydrogen, a highly flammable gas used in the etching process of a gas box in the semiconductor industry. The CFD simulation was conducted to investigate the safety of semiconductor production facilities in relation to the explosion risk. Flow analysis was performed for the interior of a gas box used in the etching process. A steady-state analysis was performed to predict the concentration range of the explosion limit in the case of continuous hydrogen gas leakage. The interior of the gas box used in the simulation was modeled, and the ventilation flow rate, which has a significant impact on the leakage gas concentration distribution, obtained from experiments was used. The lower flammability limit (LFL) value of the leaked gas was 4% based on H2, and LFL/4 (25% of the LFL) was analyzed as the explosion limit concentration according to the acceptance criteria of the SEMI S6 tracer gas test. To validate the CFD simulation, a tracer gas test was performed according to SEMI S6. A mixture of hydrogen (5%) and nitrogen (95%) was used as the tracer gas. The flow rate was controlled by a gas regulator valve and measured using an Aalborg mass flow meter. The measured concentration of the tracer gas was calculated using the equivalent release concentration, which was calculated when 100% of the hydrogen was released, and the risk was assessed by comparing it with the LFL/4 of H2.

Rancang Bangun Alat Pendeteksi Kebocoran Gas LPG Berbasis Internet of Things Dengan Katup Regulator Otomatis

Liquefied Petroleum Gas (LPG) is a flammable gas. Leaks in LPG gas cylinders that are not known to the user can have a fatal impact if there is no system that detects and stop the leak. Therefore, this study designed a system to detect and solve LPG gas leaks based on the Internet of Things automatically. The way this system works is that the MQ-6 sensor detects the concentration of LPG gas around the cylinder with an analog value limit when the safe condition is <400 and the danger condition is 400. The sensor will continue to detect as long as the tool is on and send data to the microcontroller in the form of NodeMCU ESP8266 which then transmits the data to Firebase. From Firebase, users will get information about LPG gas levels in safe/dangerous conditions, gas position control, as well as fan and buzzer conditions through a smartphone application in real time. If the conditions are safe, the green LED will light up and the condition is dangerous, the microcontroller will physically respond to the servo motor to turn the regulator valve open, the fan, the red LED and the buzzer while virtually the user will get information through the application and notifications via the WhatsApp application in the form of a short message as a warning that gas was detected. The test results show that the LPG gas detection system can work well.

ОБОСНОВАНИЕ ПАРАМЕТРОВ ПЕРЕДАТОЧНОГО МЕХАНИЗМА СИСТЕМЫ АВТОРЕГУЛИРОВАНИЯ ТРИЕРА

An analysis of the operating conditions for the use of grain cleaning technologies is given. The necessity of automatic adjustment of the speed mode of the trier operation, taking into account the variability of the supply of grain mixture, is substantiated. A constructive scheme of the transmission mechanism of the automatic control system for the operation of the trier is proposed. It is substantiated that the relationship of the angles of rotation of the control and controlled links with the advance of the increment of the latter in the entire range of regulation is provided with a sliding contact between them. The rotation angle ranges of the control (α) and controlled (β) links are 19° and 27.6°, respectively. It is theoretically confirmed that the initial ratio of increments of angles (Δβ and Δα) is 1.4, and the final one is 1.75. This ensures a high quality of reproduction of the optimal high-speed modes of operation of the trier for each of the six levels of the interval-changing value of the feed of the grain mixture. The initial values of the lengths of the control and controlled links from the point of their contact to the axes of rotation are 70 and 50 mm, respectively. The initial position of the control link relative to the horizon is 54.75°. Its rotation together with the shaft of the regulator valves before contact with the controlled link, when the supply Wmin = 1.2 t/h is ensured, is 35.75°. Setting the controlled link on the handle of the fixed resistor to its original position is carried out after it is rotated through an angle of 172.1°, which ensures the minimum speed of the trier - nmin = 34 rp/m.

Study on the characteristics of self-developed pulverized coal flow regulation valve for coal gasification process

Pulverized coal flow regulation valve is one of the key equipment of pulverized coal gasification process, which plays an essential role in regulating coal flow rate. However, due to complex valve flow channels and gas-solid interactions, there were few reports on the characteristics of this valve. In this paper, experiments of dense-phase pneumatic conveying were carried out with a self-developed pulverized coal flow regulation valve installed in the pipeline. Firstly, the effect of the valve opening on the pressure distribution of the conveying system was analyzed. Then, the flow patterns of gas-solid two-phase flow inside the vertical pipe and inside the horizontal pipe were investigated by the Electrical Capacitance Tomography (ECT) system, respectively. Finally, after analyzing the influence of the regulation valve on the gas-solid flow parameters and based on data regression analysis, the relationship between valve opening and solid velocity and concentration were fitted, and a semi-empirical model was established for pulverized coal flow rate prediction. The model can effectively predict the pulverized coal flow rates under different valve openings with deviations mostly less than± 10%, which is of great significance for flow rate regulation in practical applications.

Changes in Cough Reflex Sensitivity in Children After Removal of Hypertrophied Adenoid Tissue.

PurposeThe co-occurrence of adenoids and chronic cough is common in children. The goal of this research was to specify changes in cough reflex sensitivity as a result of adenoid tissue removal.Patients and MethodsThe sample group consisted of 17 children (six boys and 11 girls, aged 4–12 years, mean age 6.24 years), all of them possessing symptoms of chronic cough and adenoids, confirmed by nasal fiberoptic endoscopy. This sample group underwent cough reflex sensitivity assessment, which took place both prior to and after endoscopic adenoidectomy. The definition of the cough reflex sensitivity is the lowest capsaicin concentration that caused two (C2) or five (C5) coughs. Capsaicin aerosol in ascending concentrations (from 0.61 to 1250 µmol/L) was inhaled by a single-breath method (KoKo DigiDoser), with the addition of an inspiratory flow regulator valve (RIFR).ResultsConcentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Cough sensitivity (geometric mean with 95% CI) for C2 was 31.86 (12.98–78.18) µmol/L preoperatively and 11.97 (6.16–23.26) µmol/L postoperatively (P=0.064). Cough sensitivity for C5 was 234.91 (97.19–567.77) µmol/L preoperatively and 69.13 (29.08–164.35) µmol/L postoperatively (P=0.022). The children’s pulmonary function was within the normal range.ConclusionIn our study, adenoidectomy significantly increased cough reflex sensitivity in non-atopic children suffering from chronic cough.

Research on recovery and utilization of waste heat in advanced compressed air energy storage system

In order to improve the efficiency of the advanced compressed air energy storage system, a method for recycling the system exhaust gas and waste heat of heat exchange working medium is proposed. A low expansion ratio expander is added to the original system. Residual heat enters the expander to work to increase the total output of the system. The Aspen Plus software is used to establish a four-stage advanced compressed air energy storage system model under steady-state operating conditions and perform simulation. The simulation results show the maximum increment of system output power is 4713.72 kW and its corresponding increment of system efficiency is 7.34% in comparison with no waste heat recovery, and verifies the effects of different expander exhaust pressures and pressure regulator valve outlet pressures on system efficiency and output power.

​Weed Control using Pre-emergence Herbicide Strip Application System Along with Sowing/Planting Devices

A 6-row pre-emergence herbicide strip-application system was designed and developed at ICAR-CIAE, Bhopal as an attachment to inclined-plate planter to apply herbicide at the time of sowing in widely spaced crops to control weeds along the crop rows, often not possible in mechanical weeding. It consisted of a frame on which 6 flat fan spray nozzles were mounted by means of clamps, a single action piston pump with 9 l/min capacity, pressure regulator valve and pressure gauge and pressure pipes. The spacing between the spray nozzles, angle and height of spray nozzles can be varied by adjusting the clamps. The developed system has ability of strip as well as blanket application of herbicide. The same machine can be used as post-emergence herbicide/pesticide applicator after the removal of furrow openers and increasing the height of nozzles from the ground. The machine was tested and evaluated during Kharif season for soybean and pigeon pea crops. The field capacity of the developed system was found to be 0.4 ha/h. The operating cost of the pre-emergence herbicide applicator with inclined plate planter was worked out as Rs 1350/- per ha. It can save about 40-50% herbicide.

Experimental research on universal characteristics and output performance of pneumatic motor for compressed air vehicle

Compressed air vehicle is characterized by low cost, easy operation, and zero pollution. In this study, a compressed air vehicle test table is built based on pneumatic motor (PM). Influences of key parameters, such as regulator valve pressure, rotation speed, and torque on exhaust pressure, intake pressure, expansion ratio, volume flow rate, power output and compressed air consumption rate of PM are discussed. Universal characteristics curve is an important reference to analyze the performance of PM. Hence, universal characteristics of PM is analyzed. Finally, relative error, error bar and sensitivity analysis of the experimental are discussed. Experimental results show that the high-power region of PM falls around regions with great volume flow rate, relatively high torque, and moderate rotation speed. For PM, the most economic region is expected to fall in the center of universal characteristics. Moderate torque and rotation speed are the relatively economic operation regions of PM. When the regulator valve pressure is 9 bar, the torque is 11 N·m, and the rotation speed is 880 r/min, the power output of PM reaches 1014.5 W.

A resonant piezoelectric proportional valve for high-flowrate regulation operated by a bending sandwich actuator

A resonant piezoelectric proportional valve for large flowrate regulation was proposed in this work. The large flowrate of the valve and its proportional regulation under high differential pressure were achieved using a bending sandwich actuator (BSA). First, the configuration and operation principle of the valve were depicted, and its structural parameters were determined by simulated analyses. Then, the theoretical analysis method was accomplished to predict the flowrate, and the direct fluid structure interaction simulation was used to validate the theoretical model. Ultimately, a prototype was fabricated and experimentally measured for the output performances. The results denoted that the output displacement of the BSA under the loaded condition was 91.69 μm when the resonant frequency and voltage were 2.19 kHz and 100 Vp-p; and the corresponding flowrates for the deionized water (DIW) and silicone oil (SLO) were 1.256 L/min and 0.221 L/min at 344.75 kPa. Besides, the cut-off pressures for the DIW and SLO were 289.59 kPa and 310.275 kPa under −300 V0-p; and the leakages were 0.5 mL/min and 0.2 mL/min under 344.75 kPa. This valve is expected to be applied to the cooling systems, hydraulic actuators.

Investigation on the Characteristics of a Combination Microflow Control Valve

Flow control valves have broad application prospects in aviation hydraulic systems. This paper proposes a combination microflow control valve (CMCV) instead of the traditional valve to optimize the performance. Influences of structural parameters of CMCV on its characteristics are numerically investigated to determine the static and dynamic characteristics of CMCV. The calculation results indicate that there is a negative feedback control between stages of the flow regulator, the orifice pressure drop is compensated, and the flow regulation deviation is reduced. The orifice area and the flow regulator valve port area have significant effects on flow characteristics. The diameter of orifice, the spring stiffness, the number of throttle holes, and the ultimate displacement of sleeve are positively correlated with the flow rate stability value of the valve. The valve port flow area gradient and initial overlap of the flow regulator affect the flow rate fluctuation range and response time of CMCV.

A new mixed integer non-linear programming model for optimal PAT and PRV location in water distributionnetworks

ABSTRACT Water distribution network are energy-demanding systems affected by low efficiency. In such systems, the pressure is generally kept under control by regulation valves to reduce the waste of water due to the leakages. The employment of energy production devices may be an efficient strategy to both reduce waste of water and produce energy, whose feasibility basically depends on the amount of recoverable energy, though. In this study, the optimal location of both pumps as turbines (PATs) and pressure-reducing valves (PRVs) within a literature water distribution network is investigated to maximize the production of energy and water savings. A new mixed integer non-linear model has been developed and a global optimization solver has been employed to perform the optimization. According to the results, the new optimization ensures good solutions, in term of water and energy savings, when compared with other procedures in literature.

Simplified Indirect Estimation of Pump Flow Discharge: An Example from Serbia

In the absence of a flowmeter or due to its inaccuracy, the flow rate at the discharge section of the pipeline following the observed pump can be roughly estimated if the pressure can be measured instead. To use the proposed procedure two main conditions should be achieved: (1) a manometer should be installed at the discharge pipeline between the pump and the flow regulation valve, and (2) the actual curve that relates pressure and flow for the observed pump unit should be known in advance. The described example is from Serbia, but it is of interest for any water pumping station with a submersible pump (installed in wells or tanks) where a limited number of adequate places for the measuring of flow are available (if any are available at all), but where the pressure at the discharge pipe of the observed pump can be measured. This simplified method can find applicability in installations in remote rural regions where limited resources are available. The results show that the calculated values of the flow obtained by the presented method deviate greatly in relation to the measured values provided by the portable ultrasonic flowmeter, up to 60% at one of the measuring points. However, in relation to the measured values provided by the permanently installed flowmeter the discrepancy is significantly lower (0.6–6.8%).

Experimental study on small power generation energy storage device based on pneumatic motor and compressed air

Compressed air energy storage has garnered much attention due to its advantages of long lifespan, low cost and little environmental pollution, and pneumatic motor is equally so due to its advantages of low price, easy operation, and wide power range. In this paper, a small power generation energy storage test device based on pneumatic motor and compressed air is built. The effects of regulator valve pressure and electronic load current on temperature difference, pressure difference, expansion ratio, rotating speed, torque, power output of pneumatic motor, and efficiency of generator are studied by experiments. The experimental results show that the temperature difference, pressure difference and expansion ratio of pneumatic motor increase with the increase of regulator valve pressure and electronic load current. The power output of the pneumatic motor and the efficiency of generator increase at first and then decrease with the increase of the electronic load current, while the power of pneumatic motor and the efficiency of generator increase with the increase of regulator valve pressure. The maximum power output of the pneumatic motor is about 290.3 W, and the maximum efficiency of the generator is about 75.1%.

Ensuring the Safety of Gas Distribution Stations When Increasing Capacity

The paper shows the dynamics of accidents and industrial fatality injuries at the Main Pipeline Transport of Hydrocarbons in the Russian Federation. The features of operation of a Gas Distribution Station (GDS) as one of the Hazardous Production Facilities of Main Pipeline Transport of Natural Gas are considered. The main technological units and systems for ensuring the complex safety of automated low-performance GDS are presented. The main factors contributing to the occurrence and development of accidents at the GDS are listed. To increase gas supplies to the consumer, the calculation of the technically possible throughput capacity of the existing GDS with a design capacity of 20 thousand m3/hour was carried out. Using a software complex “Vesta-GDS” we built process flow diagram that under the given constraints (pressure, temperature, gas velocity in the pipeline and the degree of opening of the gas pressure regulator valve) determined that the technically possible throughput capacity of GDS is 16.37 thousand m3/hour more than design capacity. With technically possible increased productivity, a qualitative and quantitative assessment of the risk of an accident at the GDS II class of danger was made, as a result of which the risk was assessed as “low” and not exceeding the background indicators of the oil and gas industry of the Russian Federation.

Relationship between cough reflex sensitivity and body mass index in children with chronic cough - a pilot study.

Obesity is characterized by chronic, low-grade systemic inflammation. Obesity may also be associated with chronic cough. The aim of this pilot study was to clarify relation of cough reflex sensitivity and body mass index (BMI) in children with chronic cough. Altogether 41 children having symptoms of chronic cough were submitted to cough reflex sensitivity measurement. We assessed the relation of cough reflex sensitivity (CKR) due to BMI. Cough reflex sensitivity was defined as the lowest capsaicin concentration which evoked two (C2) or five (C5) coughs. Capsaicin aerosol in doubling concentrations (from 0.61 to 1250 micromol/l) was inhaled by a single breath method (KoKo DigiDoser; nSpire heath Inc, Louisville, CO, USA), modified by the addition of an inspiratory flow regulator valve (RIFR; nSpire heath Inc, Louisville, CO, USA). BMI was calculated. Pulmonary function was within normal range. Concentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Children (22 boys and 19 girls, mean age 6.8 years) cough reflex sensitivity (median, with the Inter-Quartile Range) for C2 was 19.5 (73.4) micromol/l; for C5 it was 78.1 (605.5) micromol/l. We have noticed statistically significant relation of the cough reflex sensitivity (C5) and body mass index (P<0.0001); however, the effect size was small, R2=0.03. Increase of body mass index in one unit is associated with -34.959 micromol/l decrease of C5. We did not find a statistically significant relation between C2 and BMI (P=0.41). The median value of CKR (C2) in boys is not statistically significantly different than the median value of CKR (C2) in girls (P-value 0.5). The median value of CKR (C5) in boys is not statistically significantly different than the median value of CKR (C5) in girls (P-value 0.5). Increase of body mass index in children suffering from chronic cough relates to decrease of cough reflex sensitivity (C5 value).

Development of a High Differential Pressure Piezoelectric Active Proportional Regulation Valve Using a Bending Transducer

In this article, a piezoelectric active proportional regulation valve with high differential pressure is proposed based on a bending transducer. The output flowrate of the valve can be accurately controlled by a bending transducer. The configuration design and driving principle of the valve are presented and analyzed. The static analyses are performed to determine the structural parameters of the valve and deduce its transient overflow gap. On this basis, the overall flowrate model of the valve is established using the theory of circumferential flow and extended Bernoulli equation. The effects of differential pressure and driving voltage on output flowrate are clarified. A prototype of the valve is manufactured and the experimental setup is also established to evaluate the performances of the valve. The results indicate that the proportional regulation of the valve can be achieved by changing the driving voltage; the valve displacement and response time under no liquid-loading condition are 16.16 μm and 340 μs at the voltage of 300 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p-p</sub> ; the maximum output flowrate is 286.3 mL/min under the differential pressure of 344.75 kPa, and the leakage level is 0.11%; the maximum cut-off pressure of 275.8 kPa can be realized; the corresponding input power is 185 mW.

The implementation of optimized drip irrigation system based on semiconductor sensors

This article presents an optimized version of a drip irrigation system based on semiconductor sensors. In this study, the organizational parts of the drip irrigation system based on semiconductor sensors are fully automated, namely: control of the water base, water volume in the pipe, water velocity in the pipe, soil moisture, salinity, temperature, ph of hydrogen content in the soil, pressure regulator valves. The electrical properties of a drip irrigation system based on semiconductor sensors have been proven, on the basis of which a semiconductor material can achieve an optimal result. The system provides economic indicators for one hectare of land and an analysis of the complete replacement of imported products.

Investigation of Ultra-High Pressure Gas Control System for Hydrogen Vehicles

With the increasing demand to find new energy resources instead of using fossil fuels, for the protection of the environment, one of most attractive areas in renewable energy is hydrogen. Hydrogen gas has high energy efficiency, generates the least greenhouse gases and produces no noise. Moreover, overland transportation industries have been researching and developing hydrogen gas storage systems worldwide. Such a manner of fuel system consists of a hydrogen gas tank, high pressure regulator and solenoid valve, etc. In this paper, a test bed is suggested for ultra-high pressure systems integrating a valve and regulator with precision control. We carried out performance tests by applying voltage with wide ranges of input pressure, response time and output flow rate and pulsation repetition tests considering increases in temperature, etc. Moreover, the results indicated good potential for application in fuel charging and transporting commercial hydrogen vehicles.