Supply Valve Research Articles

Remote Detection of Leakages from a Compromised Buried Water Supply Pipe through Geophysical Measurements

The continuous drastic loss of stored water at a private household presumed to be caused by leakage(s) was subjected to geophysical investigations with a view to delineating the source(s) of the leakage(s). The Spontaneous Potential (SP) and Electrical Resistivity (ER) methods were deployed for the study. Measurements were taken along four (4) traverses at two intervals – firstly when the water supply valve from the overhead storage tank was closed and secondly when it was opened. The Total Field array was adopted for SP measurements with constant station separation of 0.5 m. ER measurements were taken via the Wenner array with electrode spacing (a) varied with an interval of 0.5 m from 0.5 m to 1.5 m. SP data were presented as profiles and maps while ER data were presented as 3-D resistivity depth stacks. SP values varied from -100 mV to 350 mV during the two measurement periods. ER values also varied from 100 ohm.m to 1200 ohm.m during the closed valve period and 100 ohm.m to 900 ohm.m during the opened valve period. During the closed valve period, pipeline routes were interpreted as manifesting oval-shaped high potential anomalies with central linear trend on the SP map; and as linearly-trending high resistivity intrusion within low resistivities on resistivity maps. The disparities between the results of closed valve and opened valve measurements were pointers to leakage-induced inhomogeneity in the subsurface. The diminished high potential SP anomaly and the anomalously low resistivity specks within linearly-trending high resistivity values were regarded as the source of leakage.

How to better match predicted loads of district heating system: A novel control approach focused on coupling source and network by data-driven methods

Deconstructing the load forecast into appropriate control parameters is essential for effective intelligent heating control. Drawing from the predicted load, a novel heating control approach is proposed, emphasizing the integration of source and network. The heating regulation of the energy station is achieved through controlling the supply water temperature, while the thermal entrance of the heating network is regulated by adjusting the flow rate using valve control. The heat transfer mechanism influencing the regulation of District Heating Systems (DHSs) operation and the alignment of supply and demand are analyzed to deconstruct the four key factors: load, flow, load-flow ratio, and supply water temperature. Multiple Linear Regression (MLR) method is employed to formulate the parameter equations relating to supply water temperature and valve opening. Given the uncertainty interference in DHS in practice, the model undergoes periodic dynamic revisions. The model’s validity is confirmed by the empirical data from three different heating seasons. The average absolute deviation of the calculated supply water temperature and valve opening from the actual DHS is 0.42℃ and 1.12%, respectively. When implemented in an actual system, the approach effectively decreased gas consumption by 29.3% while effectively fulfilling heating requirements.

Automated Gas Line Shut Off Mechanism Using Solenoid Operated Valve and Gas Leak Detector (At the Event of Gas Leakage in PNG Line)

Gas leaks that cause deadly flames have become a major issue in homes and other places where domestic gas is handled and utilized. Gas leaks cause a variety of mishaps that result in financial damage as well as personal injuries and/or loss. The project’s goal is to create a system that detects gas leaks and notifies the subscriber through alarm and status display, as well as shutting off the gas supply valve as the main safety precaution. The turning off of the supply valve prevents further gas flow to the cooker, preventing a fire breakout caused by an attempt to ignite the cooker. The device, which functions more like a first- aid kit, utilizes a usually closed solenoid valve to shut off the gas valve before asking for assistance via visual display and loud alert to anyone in the vicinity. The system is clever in that it does not cause a loud nuisance by constantly sounding the alarm, but rather the siren stops beeping once the concentration of the gas in the atmosphere after leaking falls below the predetermined value and the valve is opened again for regular operations. This effort will reduce injuries and losses caused by explosions caused by gas leaks, as well as enhance the safety of people and property while utilizing home cooking gas.

Aeroacoustic two-port characterisation technique for ventilation valves

This paper describes a measurement method to characterise the low-frequency aeroacoustic properties of ventilation extraction and supply valves based on an active two-port formulation for network modelling purposes. The method uses a more compact controlled environment compared to commonly used semi-(anechoic) or reverberations rooms, and relies on a radiation model that assumes the valve radiates similarly to plane waves from an open duct. Using a loudspeaker excitation inside the set-up, a passive two-port model representing the reflection and transmission properties of the valve is obtained. This passive two-port model is then extended to an active two-port model including the source properties by characterising a reflection-free source vector. The resulting properties do not include the influence of the radiation impedance of the environment and can be used to estimate the reflection coefficient and the sound power radiated from the valve when the valve is backed by a different environment. Predictions of the one-port reflection coefficient and the predicted radiated airborne sound power, obtained from the experimentally characterised two-port properties of a ventilation valve, are compared to measurements using established methods in a semi-anechoic environment, showing good agreement in the targeted frequency range where plane wave propagation can be assumed.

Evaluation of supply air temperature control performance with different control strategies at air handling units

Due to its nonlinear feature, supply air temperature control systems at air handling units using single-loop fixed gain control frequently suffer unstable response under dynamic conditions. This paper is aimed at identifying a more effective control strategy to stabilize the valve control and achieve desirable supply air temperature response under various operation conditions by evaluating three control strategies, cascade, gain scheduling and cascade plus gain scheduling controls. Firstly, a control-oriented model is developed and calibrated through open-loop tests. Then, the control issues with single-loop fixed gain control are evaluated through simulations and field tests, which indicates that the system has more aggressive response or becomes unstable under lower load conditions when the chilled-water flow rate is less than 0.1 L/s. Finally, three control strategies are proposed and evaluated. The results reveal that all three proposed controls can achieve better robustness with the integral square error of supply air temperature decreased to 16%, 47% and 5%, respectively, under lower load condition. However, since high-frequency oscillation of the control valve occurs with cascade and cascade plus gain scheduling control, the gain scheduling control is recommended considering a trade-off among the supply air temperature response, valve lifetime and implementation complexity.

Compressor and Valve Control Performance Implications on Active Flow Control Aircraft

This study presents the feasibility of implementing commercial-off-the-shelf reciprocating piston compressors for a developed active flow control (AFC) actuation framework to quantify the aerospace relevant performance ramifications of control architecture and compressor operational choices. Three architectures are studied: supply valve metering, exit area metering, and a combined approach. All concepts are studied under varying compressor operation schedules. The analysis framework in this study integrates internal pneumatic actuation and discharge dynamics, an experimentally calibrated compressor pressure and thermal dynamics model, three feedback control architectures, and flight dynamics models. The framework is implemented in simulation to provide a user-friendly tool for linking AFC architecture choices to achievable flight trajectories. Actuator performance is evaluated using actuation time, output, compressor duty cycle, and specific energy consumption. Aircraft tracking performance is evaluated as usable time and slalom centerline deviation. The analysis indicates that a supply-volume-based metering approach is comparatively inefficient concerning an exit-area-based metering, resulting in high flight tracking error. Exit area metering provides the best efficiency and run time with some structural drawbacks, while the combined approach provides the best flight tracking performance at the expense of additional complexity. These results inform the choice of onboard AFC hardware choices.

ДОСЛІДЖЕННЯ ВДОСКОНАЛЕНОЇ БОКОВОЇ СИСТЕМИ ВЕНТИЛЯЦІЇ В ПТАШНИКУ ЗА ДОПОМОГОЮ CFD

One of the main factors in the poultry house is maintaining a standardized microclimate. The quality of the product output in the final result depends precisely on the quality indicators of the air parameters. Poultry during its maintenance requires significant efforts and technological solutions. In this regard, authors improved microclimate system in air environment of the poultry house by installing exhaust fans on the side wall in a total number of 8 units. CFD modeling using ANSYS Fluent is a powerful tool for predicting the air flow scheme in a poultry house and is considered an alternative to experimental studies. Based on the obtained results of CFD modeling, it was established that the valves located at a height of 330 mm from the ceiling work most efficiently. Pressure drop for the inlet valves is 45.85 Pa. Air velocity at the inlet of the supply valves is equal to 9.17 m/s. Air velocity at a height of 0.7 m from the floor level varies within 0.57 m/s, the temperature is 9.91 °С.

A Study on Points of Respiratory Assist Devices Using in Pre-Hospital Care Respiratory Assist Devices in Pre-Hospital Care.

In Japan, increasing the number of ambulance requests, the case with the use of respiratory assistance devices in prehospital care by paramedics is also increasing1. When patient experiences respiratory failure, the first responders frequently select a respiratory assist device (RAD) such as Bag Valve Mask (BVM), Jackson Rees (JR), or BVM with Gas Supply Valve® (BVM+GSV). This is based on both evaluation and experience as there is no study indicating which RAD is the best choice at the pre-hospital emergency site. This study clarified the precautions when using BVM, JR, and BVM+GSV in pre-hospital emergency medical care with healthy volunteers. Twenty healthy adults were fitted with a RAD while breathing spontaneously, and changes in vital signs and ETCO2 were observed. The level of ETCO2 became elevated after each RAD was attached. The value was significantly higher in the JR group than in the others. The study showed that even in the presence of spontaneous breathing, ETCO2 increased markedly with the application of respiratory assist devices that are used in pre-hospital care for conditions such as hypoxemia and ventilatory disturbance. The increase in ETCO2 was particularly significant in the JR group, suggesting the need for caution when selecting JRs for pre-hospital care. As the number of subjects was only 20 for each RAD, studies with a larger sample size are needed.

Intelligent PID control of an industrial electro-hydraulic system

In this study, an intelligent PID (i-PID) controller is designed for position control of a nonlinear electro-hydraulic system with uncertain valve characteristics and supply pressure variations. The proposed controller uses estimation of ultra-local model of the system. To exhibit the capability of the proposed method, the controller parameters are optimized via the particle swarm optimization method through a nominal nonlinear model of the system. Then, the performance of the i-PID controller, parameters of which are optimized by using the nominal model, is examined under uncertainties caused by valve characteristics and supply pressure variations. Moreover, the friction between the piston and the hydraulic cylinder is also considered in experiments. A PID controller whose parameters are also optimized based on the same performance criteria, is used for comparison purposes with i-PID control both in simulations and experiments. Performance metrics of the controllers are examined and presented by employing two separate reference signals: Sine wave and ramp. The results show that the i-PID controller shows significantly better results than the classical PID controller in tracking the test signals under various supply pressures and valve modes.

Design, analysis and fabrication of hydro fixture for testing of 32” and above size valve

A hydrostatic test is a way in which pressure vessels such as pipelines, plumbing, gas cylinders, boilers and fuel tanks can be tested for strength and leaks. The test involves filling the vessel or pipe system with a liquid, usually water, which may be dyed to aid in visual leak detection, and pressurization of the vessel to the specified test pressure. Pressure tightness can be tested by shutting off the supply valve and observing whether there is a pressure loss. The location of a leak can be visually identified more easily if the water contains a colorant. Strength is usually tested by measuring permanent deformation of the container. Hydrostatic testing is the most common method employed for testing pipes and pressure vessels. Using this test helps maintain safety standards and durability of a vessel over time. Newly manufactured pieces are initially qualified using the hydrostatic test. They are then re-qualified at regular intervals using the proof pressure test which is also called the modified hydrostatic test .Testing of pressure vessels for transport and storage of gases is very important because such containers can explode if they fail under pressure. Hydrostatic tests are conducted under the constraints of either the industry's or the customer's specifications, or may be required by law. The vessel is filled with a nearly incompressible liquid - usually water or oil - pressurized to test pressure, and examined for leaks or permanent changes in shape. The test pressure is always considerably higher than the operating pressure to give a factor of safety.

Research of thermal and hydrodynamic flows of heat exchangers for different air cooling systems in poultry houses

Increasing the productivity of poultry farms is connected with the need to create an optimal regulated microclimate in poultry houses. This problem becomes of primary importance due to the decrease in the productivity of poultry farming due to the imperfection of the existing systems. The purpose of the study was the development and numerical modeling of a shell-and-tube heat exchanger of a new design for cooling supply air as an element of the air conditioning system used in ventilation systems of various types in the summer period. Two types of ventilation systems are considered, namely tunnel and lateral. For these ventilation systems, heat exchangers designed to cool incoming air in the summer season have been developed. A total of 80 automatic inlet valves measuring 0.3 × 0.85 m were arranged in the side walls. In addition, evaporative cooling systems 5.3 × 1.1 m were located on the front end walls. When considering these two separate systems, the heat exchangers were installed instead of the evaporative cooling system and automatic supply valves. The processes of heat and mass transfer in developed heat exchangers for various types of ventilation systems were investigated. Numerical modeling of hydrodynamics and heat transfer was carried out, as well as analysis of the operation of heat exchangers of two different designs for tunnel and side ventilation systems. Velocity, temperature, and pressure fields in the studied channels were obtained. The conditions of the hydrodynamic flow in the channels of the heat exchangers were analyzed. In the case of the tunnel ventilation system, the pressure drop is 991 Pa, which is 3.3 times less compared to the side ventilation system. The outlet temperature is +23 ℃, which meets the design requirements. The main disadvantage is the financial costs for the purchase, cutting of pipes and, actually, their welding. Both the tunnel and side ventilation systems are quite effective. In order to ensure standardized conditions of the air environment in the poultry house, taking into account all aspects of technical and economic analysis, it is proposed to choose a heat exchanger for the tunnel ventilation system. In practice, such heat exchange devices can be used not only in microclimate systems of poultry houses, but also in the industrial, energy industry and critical infrastructure facilities

Передпускові роботи на нових коксових батареях та установках сухого гасіння коксу, запроєктованих ДП «ГИПРОКОКС».

The article considers the peculiarities of pre-commissioning works performed under the supervision of SE GIPROKOKS at the coke oven battery and coke dry cooling plant (CDCP) at the NMDC metallurgical plant, which is just starting its operation. In particular, the paper shows the difficulties of applying preheating of a coke oven battery under conditions of coke oven gas deficit - using liquefied natural gas (LPG) as a heat carrier. The most significant difference between the latter and coke oven gas is its high calorific value and the need for much more air to ensure complete combustion. Long-term operation with LPG can lead to gassing of gas supply valves. All of this led to the decision to increase the warm-up temperature according to a temporary scheme to a temperature of 1100 °C, after which the battery was to be launched. The battery was scheduled to be loaded when at least 26 coking chambers out of 67 were ready to be loaded with charge. After charging approximately 20 coking chambers, the raw coke gas was to be transferred to the coke product recovery shop, cleaned and fed to Coke Battery No. 1 for transfer to the permanent heating scheme. There were a number of problems that arose during the emergency heating. In particular, due to the fact that LPG begins to decompose into its individual components after a temperature of 950 °C, the temporary furnaces had to be cleaned of soot and graphite almost daily. The difficulties encountered during the start-up of the dry coke cooling plant, in particular, the alkalization of the boiler when using LPG as a burner fuel, etc. are highlighted. Solutions are presented to avoid similar problems in the future. In particular, the necessity to: provide for an increase in the height of temporary furnaces by 300 mm in all coke oven batteries that will be heated with LPG; improve the instructions for heating the coke oven battery and starting the CDCP, etc. Keywords: liquefied natural gas, coke oven battery, coke dry cooling plant, boiler alkalization, preheating. Corresponding author: F.F. Kachura, е-mail: anatoliykachura@gmail.com

Design features of underwater breathing apparatus

The problem of finding and disposing of explosive objects in the water areas of seas and rivers that remain as a result of hostilities on the territory of our country is urgent and requires appropriate technical equipment. The technical support (equipment) for performing underwater work, which is in service with the Armed Forces of Ukraine, is outdated and can pose a threat to the life and health of sapper divers during the performance of complex combat tasks on a regular basis. One of the pressing issues today is the transition of the Armed Forces of Ukraine to NATO standards. Taking this into account, the issue of not only transitioning to international standards that regulate the processes of development, planning, testing, operation, repair or modernization of weapons and equipment, but also the preservation of the lives of personnel during combat missions is an urgent issue. Accordingly, the search for ways to increase the safety of military personnel during diving descents with explosive work is relevant. The purpose of the study is to analyze the possibility of making structural changes in underwater breathing apparatus (UBA) with an open breathing circuit of the ABA type and to evaluate the effectiveness of the changes made using a composite efficiency index. The types of UBAs with an open breathing circuit of the ABA type are analyzed, the main advantages and disadvantages of UBAs with open, semi-closed and closed circuits of gas supply for breathing are indicated. The principlescheme of the UBA type ABA was considered and constructive solutions were proposed to increase the safety of diving descents and works. Introducing a fundamentally different design of the reducer and the reserve air supply valve into the design scheme will provide an opportunity to control the air supply in the UBA, increase the safety of diving descents and work. The proposed changes in the design will improve the safety of diving descents and underwater work. The obtained results can be used in further scientific research in the direction of modernization and development of promising means of diving equipment.

Investigation of the lateral ventilation system in a poultry house using CFD

Maintaining a normalised microclimate in a poultry house is one of the main factors. It is the quality indicators of air parameters that ultimately determine the quality of product output. Keeping poultry requires considerable efforts and technological solutions. In this regard, the purpose of the study is to improve the microclimate system in the poultry house by installing ventilation equipment on the side wall. A powerful tool for predicting the air flow pattern in a poultry house is Computational Fluid Dynamics (CFD) modelling using ANSYS Fluent. This is an alternative to experimental research. CFD modelling results have shown that the valves operate most efficiently at 330 mm from the ceiling. The pressure drop of the supply valves is 45.85 Pa. The air velocity at the inlet of the supply valves is 9.17 m/s. The air velocity at a height of 0.7 m from the floor level varies within 0.57 m/s, the temperature – 9.91°C

Pitfall of Respiratory Assist Devices in Pre-hospital Care〜A Comparison between Bag Valve Masks（BVM）, BVM with gas supply valve, and Jackson Rees〜

Pitfall of Respiratory Assist Devices in Pre-hospital Care〜A Comparison between Bag Valve Masks（BVM）, BVM with gas supply valve, and Jackson Rees〜

MATHEMATICAL MODELLING OF THE VENTILATION SYSTEM OF A RESIDENTIAL BUILDING IN CONDITION THAT DIFFER FROM STANDARD

The natural ventilation systems of multi-story residential buildings are designed to meet the requirements for maximum air exchange. Their calculations under conditions significantly different from the standard, usually do not carry out and therefore do not provide measures to prevent their unstable operation. The article presents the results of the analysis of the ventilation system of a two-room section of a ten-story residential building using a mathematical model. To supply air to the apartment, ventilation valves are used. The air is removed from the apartments through two ventilation ducts. All apartments, except the last two floors, are connected to them via satellite channels. The system of equations of the model is based on the graph of the hydraulic network. It includes equations of the balance of air flow in the nodes of the graph and equations of pressure change in the links. In this case, the data presented in the catalogs of equipment manufacturers was used. The calculation results for conditions that differ from the design ones are presented, such as: significant differences in the supply air flow in individual apartments, the use of exhaust fans in some apartments, low outdoor temperature. The model under consideration allows us to explain the observed in practice air penetration through ventilation ducts from one apartment to another. It is shown that the main causes of this phenomenon are the low air transmission of modern window structures and the high hydraulic resistance of the supply valves, the use of ventilation ducts with various hydraulic resistances. The proposed approach allows already at the project stage to quantify the operation of the ventilation system in conditions that differ from standard and to optimize its design.

A model predictive controller of the blowing mode during basic oxygen furnance process

Today in Ukraine and the world, the problem of energy saving and reducing the cost of smelted steel is state of art. Metallurgical enterprises are developing in conditions of fierce competition, the main reason is that Ukrainian products are extremely energy-intensive due to the depreciation of fixed assets and outdated technological processes. The basic oxygen furnace process is a process of producing steel from liquid cast iron with the addition of steel scrap to the converter and blowing oxygen from above through a water-cooling lance. Nowadays, the production of steel by BOF process is the most popular in the world and is becoming increasingly common. The main disadvantage of the basic oxygen furnace is the need to provide the initial amount of heat (in the form of liquid cast iron) and as a consequence - restrictions on the processing of scrap metal. Reducing the cost of basic oxygen furnace steel is achieved by increasing the share of scrap metal by increasing the degree of afterburning of CO to CO2 in the cavity of the converter, by optimal control of the parameters of the blast mode using model-predictive control. The principle of model-predictive control is based on a mathematical model of the plant. This approach minimizes the functional that characterizes the quality of the process. The linear-quadratic functional was chosen. A forecasting model is proposed taking into account the constraint on changing the position of the lance and the pneumatic oxygen supply valve. It was found that the change in the rate of decarburization of the metal depends on the distance of the lance to the level of the quiet bath and affects the degree of afterburning of CO to CO2. The decarburization process is non-stationary, described by a first-order inertial model, the transfer coefficient and time constant of which depends on the melting period and the duration of the purge. The mathematical model of the blast mode of oxygen-converter melting has been improved, taking into account the influence of the blast intensity on the decarburization process of the bath, which allowed to increase the accuracy and quality of blast control in terms of changing oxygen flow during purging. The simulation results of the automatic control system show that the model-predictive regulator provides the required level of carbon dioxide in the converter gases when the flow rate of oxygen for purge changes.

High-throughput deterministic plasma etching using array-type plasma generator system.

A deterministic processing method is a high-precision finishing method, where the to-be-removed amount of material at each pointof the work surface is calculated based on an accurately measured present surface shape and is removed precisely using a numerically controlled (NC) processing system. Although this method has achieved nanometer-scale accuracy, the method requires considerable time to scan the work surface, leading to low productivity. Therefore, using an individual on-off controllable array-type plasma generator covering the entire work surface, enabling simultaneous NC plasma processing is proposed herein. A novel intermittent gas flow system was constructed using cyclic on-off control of the gas supply and exhaust valves instead of the commonly used continuous gas flow to achieve uniform in-plane plasma etching. It was found that uniform removal could be achieved by combining it with a pulse-modulated high-frequency power supply and setting the plasma generation time in one cycle to be sufficiently short. Furthermore, a power control approach was developed for maintaining a constant plasma state, even while varying the plasma-generating array elements, which resulted in a demonstration experiment of NC plasma etching that successfully reduced the thickness variation of a silicon substrate.

Computer modeling of the heat exchange process in the calefacient chamber of the evaporator

A system analysis is considered in the construction of a computer model of processes in the heating chamber of a steam heat exchanger, based on the MATLAB application program, by combining blocks of process models of the quasi-apparatus of the regulatory body, the steam zone, the condensate and the wall. According to the computer model of the dynamics of the heating chamber process, depending on the changes in the input parameters (steam pressure in the heating water supply pipeline, changes in the opening coefficient of the heating water supply valve, the temperature of the heating steam in the heating water supply pipeline, the heat sink from the wall), the computer automatically calculates the values of the heating steam pressure, the flow rate of the heating steam passed through the control valve, the condensation temperature of the heating steam, the wall temperature. Calculations show that with an increase in the pressure in the supply line of heating water vapor or the opening of the valve, the steam pressure in the heating chamber increases, along with this, the condensation temperature increases, and the transfer of heat energy through the heat exchange wall increases. For the example under consideration, when the water vapor pressure in the heating chamber increased to 250 kPa, the condensate temperature increased to 1200C.

A framework for model-based assessment of resilience in water resource recovery facilities against power outage

Current practice to enhance resilience in Water Resource Recovery Facilities (WRRFs) is to ensure redundancy or back-up for most critical equipment (e.g. pumps or blowers). Model-based assessment allows evaluation of different strategies for quantitatively and efficiently enhancing resilience and justifying the allocation of resources. The goal of this study is to provide guidance for the development of tailored deterministic models of full-scale WRRFs. A framework for model-based resilience assessment is proposed that provides guidance on data collection, model selection, model calibration and scenario analysis. The framework is embedded into the Good Modeling Practice (GMP) Unified Protocol, providing a new application for resilience assessment and an initial set of stressors for WRRFs. The usefulness of the framework is illustrated through a resilience assessment of the WRRF of Girona against power outage. Results show that, for the Girona facility, limited energy back-up can cause non-compliance of WRRF discharge limits in the case of a blower power shut-down of 6 h, and around 12 h when the blower shut-down is also combined with a shut-down of the recirculation pumps. The best option to enhance resilience would be increasing the power back-up by 218%, which allows the plant to run with recirculation pumps and blowers at minimum capacity. In such a case, resilience can be further enhanced by manipulating the air supply valves to optimise the air distribution, to balance oxygen needs in each reactor with the overall system pressure. We conclude that, with industry consensus on what is considered an acceptable level of resilience, a framework for resilience assessment would be a useful tool to enhance the resilience of our current water infrastructure. Further research is needed to establish if the permit structure should accommodate levels sof functionality to account for stress events.