Temperature-controlled Sensor Research Articles

Research and implementation of fault data recovery method for dry-type transformer temperature control sensor based on ISSA-LSTM algorithm

This study proposes a temperature control sensor fault data recovery model based on the improved Sparrow Search Algorithm (ISSA) optimizing Long Short-Term Memory (LSTM) to address erroneous data output caused by temperature monitoring sensor failures in dry-type transformers. The model aims to recover faulty sensor data in dynamic processes. It enhances the algorithm by initializing the population using Tent chaotic mapping, employing t-distribution and differential variation perturbations, and introducing a dynamic step size factor. Simulation experiments evaluated the performance of ISSA-LSTM, SSA-LSTM, PSO-LSTM, GA-LSTM, and ACSA-LSTM algorithms. The ISSA-LSTM model outperforms the worst PSO-LSTM model by 82.6%, 82.1%, and 1.8% in terms of MAE, RMSE and R2 values, respectively. Field experiments confirmed the algorithm's effectiveness in recovering data from faulty sensors and different fault types, improving the accuracy and stability of temperature control sensor fault data recovery in dry-type transformers.

A novel temperature-responsive electrochemical sensing platform for reversible switch-sensitive detection of acetamidophenol.

A novel facile, quick, and temperature-controlled sensor was constructed based on a polystyrene-poly-N,N-diethyl acrylamide-polystyrene (PS-PDEAM)/carboxylated multi-walled carbon nanotube (MWCNT) composite modified glass carbon electrode. The sensor achieves acetaminophen (AP) reversibility through better temperature sensitivity. PS-PDEAM shrinks when the temperature exceeds its lower critical temperature (LCST). When AP molecules pass through the modified interface, the electron transfer rate is accelerated, and the sensor is turned on. In the off state, the electrochemical response of AP cannot be detected. Under ideal experimental conditions, for composite modified films, there is a wide detection range of AP between 1.5-85.1 μM and 85.1-235.1 μM, and the limit of detection of acetaminophen is as low as 0.57 μM (S/N = 3). This method has been successfully applied to the determination of AP in tablets, and shows high stability, good reproducibility and excellent anti-interference ability. The on-off sensor opens up a wide range of possibilities for the use of temperature-sensitive polymers in electro-catalysis, sensors, and environmental pollutant monitoring.

Transient Energy Models of Housing Facilities Operation

Buildings are the main consumer of energy resources in the total energy balance of the countries in Central and Eastern Europe, the main energy consumption is allocated for heating. Efficient use of energy resources for heating needs to a large extent depends on the efficiency of regulation of heating systems. In the article, dynamic mathematical models of a two-room typical apartment in Ukraine, built in 2016, were developed in Matlab and EnergyPlus software environment. The simulations were carried out using IWEC hourly climate data for the city of Kyiv. The results of simulations of thermal energy consumption in Matlab are characterized by a larger range of fluctuations of the heating system load, which is typical for the real operating conditions of the system with the controller of ON/OFF type. In EnergyPlus it is assumed that the gas boiler operates continuously in the ON mode. In the research, the change of load on the apartment heating system was studied at different numbers and locations of air temperature control sensors installation, according to which the controller of the autonomous gas boiler operates.

Development and Research of the System for Control of Parameters of Manufacture of Halva Technological Process

The paper considers the solution of the scienti­fic and practical problem of improving the system of control of the parameters of the technological process of halva production from the creation of the structu­ral scheme to the development of the electrical circuit diagram. The results of direct multiple measurements obtained from the control system, namely the humi­dity and temperature sensor (SHT21), have been pro­cessed. The equations of direct and inverse regression were constructed and the nature of the relationship between temperature and humidity was established using the pair correlation coefficients.
 The developed control system makes it possible to provide a relative measurement error of not less than 2,5 %. Control systems are proposed for use at halva plants with the duty to control the basic parameters of the process to ensure the production of quality products.
 The measuring device includes the follo­wing primary measuring transducers: raw material moisture sensor (FIZEPR-SW100.11.x), air humi­dity sensor (SHT21), water temperature sensor, ca­ramel mass, halves during mixing (DS18B20 Dallas Semiconductor model), temperature control sensor halva storage air (ADT7420). ATmega16 was used as the microcontroller. The proposed meter is capable of transmitting data up to 50 m over a 2,4 GHz radio channel with a SPI interface to the microcontroller. This transmission enables the nRF24L01 radio to operate at 2,4 GHz (Wi-Fi frequency).
 The need to improve the existing meter has been proved by the use of a radio channel due to the fact that at this time it is necessary to avoid using wired interfaces where possible, due to the inability, sometimes, to draw communication lines due to the pre­sence of already installed equipment.

Numerical Optimisation of a Helicopter Engine Inlet Electrothermal Ice Protection System

<div class="section abstract"><div class="htmlview paragraph">This paper details the process involved in the numerical optimisation of a helicopter engine inlet electrothermal ice protection system. Although the process was developed using a production aircraft, it is demonstrated here using a generic intake and flight conditions, due to confidentiality of the actual design. The process includes adherence to the overall system design objectives (maximum power demand), including tolerances required to account for an industrial system (aircraft voltage variation, manufacturing tolerances). The numerical optimisation was performed using a combination of 2D and 3D methods to define the required heated area, power density, locations and settings for temperature control sensors. The use of 2D design tools allows a rapid iteration process to be performed, leading to the possibility of a higher level of optimisation within the allowable time-frame compared to the use of full 3D methods. Different flight settings (different Angle of Attack and Angle of Sideslip) were analysed, for two different droplet diameters (MVD values of 20 microns and 40 microns, coherent with the requirements of the CS-29 Appendix C icing envelope). An iterative transient thermal analysis was then performed, over the required temperature range of 0°C to -30°C, to optimise the heater placement and heater powers, assessing the predicted level of ice accretion in all cases. Assessment in dry conditions in the range of +5°C to -30°C was also performed in order to ensure that structural over-temperature did not occur. The positions of embedded temperature sensors were defined as part of the analysis, including the temperature control values which would feed into the controller. The process was deemed to be successful as the final design was successfully tested in flight and in an icing wind tunnel facility.</div></div>

Simulation of standard temperature control indications at the outlet of a fuel assembly of VVER1000 reactor of Rostov NPP unit No. 2

Abstract In 2016 OECD put forward a routine problem to simulate the operation conditions in VVER-1000 reactor of Rostov NPP unit No. 2 taking into account control rod motions. The participants were encouraged to simulate the integrated process and obtain the indications of the hot leg temperature control sensors depending on control rod motions. The data from in the experiment at 75% nominal power was selected for the first test carried out in the frames of the international task. Insertion of the 10th and 9th CPS rod groups into the core without driving was carried out in the low power testing experiments at Rostov NPP unit No. 2 (May 31, 2010). The task was split into several subtasks, each with its own specifics. One of such subtasks is focused on the simulation of the standard temperature control indications at the FA outlet. The way of solving the abovementioned subtask is reflected in the present report.

WAYS TO MANAGE HEATING INERTIA

Purpose. The research paper proposes to estimate the effect of heat inertia of the water heating system, in transient operation modes, on the temperature condition in the passenger car, as well as to offer technical solutions intended to reduce the heating system inertia effect and to maintain a stable temperature condition in the passenger car premises in transitional modes of the heating system. Methodology. The author developed the method for controlling the heat transfer of heating system pipes with the help of regulating casing. To control the heating system and the heat transfer of heating pipes, two types of temperature control sensors were used in the passenger car: certain sensors interacted with regulatory casings, while the others interacted with high-voltage tubular heating element control devices. To assess the efficiency of heat interchange regulation of heating pipes and the heating system control, with installed regulating casings, the operation of the heating system with regulating casings and two types of sensors was mathematically modelled. Mathematical modelling used the experimental test data. The results of experimental tests and mathematical modelling were compared. Findings. Currently in operated passenger cars, control of heating appliances is not constructively provided. Automatic maintenance of the set temperature in a passenger car is limited to switching on and off of high-voltage tubular heating elements. The use of regulating casings on heating pipes allows reducing the effects of heat inertia and maintaining stable thermal conditions in a passenger car, using the heating system as a heat accumulator, and also provides the opportunity to realize an individual control of air temperature in the compartment. Originality. For the first time, the paper studied the alternative ways of regulating the temperature condition in a passenger car. Using of the heating system as a heat accumulator. Practical value. The regulation of the heat transfers of the heating pipes by regulating casings allows reducing the effect of thermal inertia of the heating system on the temperature condition in a passenger car, implementing individual adjustment of air temperature in a compartment within 40% of the power of the heating pipe section, using the heating system as a heat accumulator.

Lessons learnt during the design, construction and start-up phase of a molten salt testing facility

In 2010, CIEMAT (Centro de investigaciones energéticas medioambientales y tecnológicas) signed a turn-key contract to have an experimental plant for thermal storage using molten salts at its PSA (Plataforma Solar de Almeria) facilities. This plant was designed to evaluate components, instrumentation and operation strategies and to give support to the industry in the qualification and evaluation of components.During the design, construction and start-up phases of this plant, many different aspects regarding design, construction and commissioning have been learnt and these will contribute to the improvement of other plants.Among other tips explained in the paper, we recommend the use of venting valves to eliminate the water present in the system after the pressure test or released by the salts during the first melting. The selection of instrumentation with no electronic components near a heat source, thus preventing them from overheating, is also advisable. The heat exchanger design and dimensioning should take into account not only the thermal losses to the atmosphere and through pipes and supports, but any possible reduction in the heat exchange surface that could have detrimental consequences in the thermal performance.Special attention must be paid when dimensioning and installing the EHT and insulation because both components are decisive in the avoidance of plug formation. Its correct installation in valves and supports and the proper positioning of the temperature control sensors, i.e. where no other heat source can distort the readings, are crucial.Recommendations and strategies for the operation and shutdown of this experimental plant are being gathered for a future paper.

Temperature Control for Seed Cotton Drying Systems

In order to determine the best recommendations for seed cotton dryer temperature control as part of ASABE standard S530.1, 20 tests were conducted during the ginning seasons of 2007, 2008, 2009, and 2010 to measure air temperature variation along various heated air seed cotton drying systems. The cooperating cotton gins were located in Texas, Arizona, New Mexico and the San Joaquin Valley, California. Drying systems tested included: standard tower, short tower, hot shelf, crossflow, hi-slip, pipe, hot box, fountain, and collider systems. Temperature measurements were taken over a 2-h time period at the mixpoint and every 2 m (6.5 ft) after the mixpoint. Although there was a significant correlation between mixpoint temperature variation and distance of the primary temperature control sensor from the mixpoint, the sensor location recommendations of ASABE standard S530.1, Temperature Sensor Locations for Seed-Cotton Drying Systems, appear to be satisfactory for seed cotton drying systems with well-maintained burners and well-adjusted temperature controls. All systems, except for the hot shelf dryer, had a larger temperature drop in the first 2 m (6.5 ft) after the mixpoint than occurred in the remainder of the drying system. Thus, for all but the hot shelf dryer, locating a temperature control sensor at 2 m or more past the mixpoint would achieve satisfactory temperature control.

Modeling Thermal Stratification in Fan-Ventilated Greenhouses

A two-dimensional thermal model was developed to investigate the thermal stratification in fan-ventilated greenhouses. Model inputs include outside weather (air temperature, humidity, and solar radiation), geometric parameters of crop rows and leaf area index, greenhouse ground and roof temperatures, ventilation rate, and operation of evaporative cooling pads. Comparing predictions with observed data indicated that the air temperature and relative humidity were modeled at acceptable accuracies, with air temperature underpredicted by 1.3C and relative humidity overpredicted by 9%, on average for a planted greenhouse. For an unplanted greenhouse, the air temperature was predicted with an absolute error of 0.7C, while for relative humidity the absolute error was 3%. Vertical temperature variation, defined as maximum temperature minus minimum temperature at approximately the central location of greenhouse, was predicted with an absolute error of 0.1C and a relative absolute error of 10% for the planted greenhouse, while for an unplanted greenhouse it was 0.6C for the absolute error and 12% for the relative absolute error. Simulations with the model suggest that increasing ventilation rate reduced the vertical temperature gradient. Increased ventilation reduced air temperature more at the top than the bottom of the greenhouse. Greater air temperature variation was produced when using evaporative pad cooling than not. Air temperature was reduced more at the bottom than at the top with evaporative pad cooling. The presence of a canopy altered the vertical air temperature distribution and reduced the temperature variation. A sample simulation showed that on a typical summer day at Raleigh, North Carolina, the presence of a canopy row with a height of 1.75 m occupying 69% of the ground area reduced the air temperature variation from 11.5C to 1.8C in a fan-ventilated greenhouse operating with a ventilation rate of 0.087 m3 m-2 s-1 and using evaporative pad cooling. The peak air temperature generally occurred at the top of canopy or somewhat below the canopy top. This finding may have some significance in establishing the location of temperature control sensors in future control systems.

Preliminary Commissioning and Energy Audit of a UNLV Building

ABSTRACT A partial commissioning and energy audit were performed on a recently constructed building at the University of Nevada, Las Vegas (UNLV). Although the building is relatively new and has passed all building code requirements, it has not undergone a formal commissioning process to check that the mechanical systems, such as the heating, ventilation, and air conditioning (HVAC), were performing at optimally designed conditions. The building is approximately 35,000 ft2 spread over three floors. The following components and systems were inspected, tested, and/or analyzed during the project: rooftop units, ducting flow rates, VAV units, room supply air fl ows, thermostats, temperature control sensors, some preliminary aspects of IAQ, some aspects of lighting, hot water heating, occupancy and occupant perceptions, and operating parameters. The building chosen has an energy management system (EMS), and hence its data can be reasonably evaluated. In addition to the inspections of the above items in the above areas, an energy use simulation was conducted using RESHEAT to test the effects of changing thermostat and hours of operation settings on the predicted energy savings in the building. The simulation showed that with the proposed changes, as much as 16.0 percent reduction of energy use could be achieved. The proposed changes resulting from this study were deemed to minimally impact the interior environment and occupants.

Further consideration of temperature measurement and control in thermogravimetry

A previous paper to NATAS in 1992 discussed the importance of more precise temperature measurement and control in quantitative thermoanalytical techniques. In particular, the locations of the temperature measurement and temperature control sensors are critical. These can have a significant effect on the determination of the beginning and ending of reactions and subsequent evaluation of relevant quantitative parameters. Experiments have been carried out on the dehydration of calcium oxalate using a thermobalance utilizing an infrared gold image furnace with the measurement and control temperature sensors. These are disposed in the three different configurations that are used in thermoanalytical techniques. Significant differences have been found between the three methods. These illustrate that using one temperature sensor for both temperature measurement and for temperature control purposes provides themost relevant data for use in further analysis of reaction kinetics, etc.

Fiber optic sensor for oxygen determination in liquids

Abstract A fiber optic sensor for the determination of oxygen in liquids is presented. Potential applications range from environmental analytics to medical diagnostics and process control. The sensing principle is based on dynamic luminescence quenching by oxygen. A ruthenium complex used as oxygen-sensitive dye is immobilized on an optical fiber by adsorption and subsequent coating with a membrane. Excitation of the Ru complex is performed both by the evanescent field associated with light guided in the optical fiber and by direct irradiation, dependent on the refractive index profile of the fiber/membrane/medium system. The emitted light is collected by the same fiber. The temperature-controlled sensor is exposed to a liquid stream of defined oxygen concentration. Oxygen is detectable in the range 0–800 Torr, with a resolution of 2 Torr in the 0–100 Torr range and of 2% for oxygen partial pressures above 100 Torr. Response times are of the order of 30 s. Generally, sensor signals are affected by sample medium. Optimized sensors exhibit a good performance, with no effects of protein adsorption or background fluorescence, even in serum.

Heating characteristics of a helical microwave applicator for transurethral hyperthermia of benign prostatic hyperplasia

A new applicator for intraurethral hyperthermic treatment of benign prostatic hyperplasia is described. The applicator uses an insulated helical antenna wound on the outer surface of a silicone urological (Foley) balloon catheter. The balloon catheter assures rapid and reproducible localization of the antenna in the prostatic urethra. Two small cannulae are fixed to the exterior surface of the applicator. One holds a temperature control sensor at a fixed location, the other is used to map temperature along the applicator. Two-dimensional SAR and steady-state temperature distributions measured in a plane tangent to the applicator in a tissue-equivalent phantom are presented, as well as longitudinal temperature distributions measured in situ at the applicator-urethral interface. Prostatic temperatures were also measured intraoperatively. The applicator appears to be capable of elevating temperature to greater than 42 degrees C in a cylindrically symmetric volume of about 4 cm length and about 0.5 cm radial penetration surrounding the antenna. The heating characteristics of this applicator are similar to an earlier design that employed an array of three dipoles. The helical applicator is narrower, more flexible and simpler to use than the earlier design.

Thermal screens — Environmental and plant studies

The microclimate and yield of an early tomato crop were studied in a glasshouse fitted with a thermal screen, which could be pulled over the crop each night to save energy. The screen was made of aluminised polyester material, slightly permeable to air, and it gave an estimated saving of 31% of the “unscreened” energy costs. The parked screen caused a radiation loss of 3–5% during the day. At night, the humidity under the screen was slightly higher than in the unscreened control, depending on outside temperature, but there was little difference in leaf—air temperatures between the plants of the 2 treatments. One important effect of the screen was the lower heat input, which reduced the convectional distribution of heat. A vertical thermal gradient developed such that young plants were 2°C colder than those in an unscreened house set to the same temperature, based on temperature-control sensors in an aspirated screen 1.5 m from the ground. Under the screen, fruiting was slightly delayed compared with the unscreened crop, possibly due to the temperature differences referred to above. Final yields were slightly higher from the screened house, but the trial was not replicated, and because of the temperature differences, the crops were not strictly comparable.

An Aluminum Block Digester for Plant and Soil Analysis

AbstractAlmost every institution, whether it be a university, a government agency, or a medical or industrial facility, that conducts research on and is concerned with the elemental analysis of biological material has a need for equipment to ash or acid‐digest samples. Often funds are not available with which to purchase commercial equipment and the researcher is required to be innovative and to design and engineer his own. Because of the lack of research funds and a need for soil and plant analysis equipment, this study was made to design and construct a large capacity, electrically‐heated and thermostatically‐controlled aluminum block digester for plant and soil samples. A drawing was prepared giving dimensions needed for shop‐work to be performed. A block of aluminum 10.2 cm (4 inches) thick was used. The block has a capacity of 126, 2.54‐cm (1 inch) diameter test tubes. The overall block dimensions are 10.2 cm (4 inches) thick, 35.6 cm (14 inches) wide, and 55.1 cm (21 11/16 inches) long. Electric heater strips are bolted to the block inside 1.9‐cm (¾ inch) milled slots. The temperature control sensor is a thermocouple inserted into the block and wired to the thermostat controller. The block heats almost linearly from room temperature to 240C at a rate of almost 4C/minute. The heating rate from room temperature to 375C is over 2C/minute and requires 2.5 hours heating time.