Temperature Control Method Research Articles

Temperature Field Analysis of Novel Die Bonding Stage for MEMS Thermopile

Packaging and die bonding of conventional micro‐electro‐mechanical‐systems (MEMS) and semiconductor devices include separate dispensing, mounting and heating curing. A novel die bonder's work stage and temperature control method are proposed so that dispensing, mounting and heating curing can be completed at the same station. This paper introduces the working principle of the thermopile sensor and the requirements for temperature change during die bonding, analyses the main structure and working process of the novel die bonding stage, and uses commercial finite element analysis software to evaluate the temperature field of the novel die bonding stage and devices during the process of heating, holding and cooling to provide process guidance for accurate temperature control of die bonding. Dispensing, mounting and heating curing are integrated in the same station, avoiding the position error of devices when transferring, reducing the number of equipment and floor area, and effectively saving production costs. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

A Temperature Control Method of Electric Heating Furnace Based on Fuzzy PID

The traditional PID control method has a series of problems such as overshoot or static error. This paper takes the electric heating furnace temperature control system as the background, combines the fuzzy algorithm to design the fuzzy PID system, and uses the MATLAB fuzzy control box to set up the fuzzy reasoning system and the fuzzy rule table., and use the Simulink platform to build the temperature control system simulation model of ordinary PID and fuzzy PID, and verify the influence of parameters on the system.

Research on thermal protection of piezoelectric pressure sensor for shock wave pressure measurement in explosion field

PurposeThe purpose of this study is to clarify the mechanism of ambient and transient temperature effects on piezoelectric pressure sensors, and to propose corresponding compensation measures. The temperature of the explosion field has a significant influence on the piezoelectric sensor used to measure the shock wave pressure. For accurate shock wave pressure measurement, based on the actual piezoelectric pressure sensors used in the explosion field, the effects of ambient and transient temperatures on the sensor should be studied.Design/methodology/approachThe compensation method of the ambient temperature is discussed according to the sensor size and material. The theoretical analysis method of the transient temperature is proposed. For the transient temperature conduction problem of the sensor, the finite element simulation method of structure-temperature coupling is used to solve the temperature distribution of the sensor and the change in the contact force on the quartz crystal surface under the step and triangle temperatures. The simulation results are highly consistent with the theory.FindingsBased on the analysis results, a transient temperature control method is proposed, in which 0.5 mm thick lubricating silicone grease is applied to the sensor diaphragm, and 0.2 mm thick fiberglass cloth is wrapped around the sensor side. Simulation experiments are carried out to verify the feasibility of the control method, and the results show that the control method effectively suppresses the output of the thermal parasitic.Originality/valueThe above thermal protection methods can effectively improve the measurement accuracy of shock wave pressure and provide technical support for the evaluation of the power of explosion damage.

High-Speed Temperature Control Method for MEMS Thermal Gravimetric Analyzer Based on Dual Fuzzy PID Control.

The traditional thermal gravimetric analyzer (TGA) has a noticeable thermal lag effect, which restricts the heating rate, while the micro-electro-mechanical system thermal gravimetric analyzer (MEMS TGA) utilizes a resonant cantilever beam structure with high mass sensitivity, on-chip heating, and a small heating area, resulting in no thermal lag effect and a fast heating rate. To achieve high-speed temperature control for MEMS TGA, this study proposes a dual fuzzy proportional-integral-derivative (PID) control method. The fuzzy control adjusts the PID parameters in real-time to minimize overshoot while effectively addressing system nonlinearities. Simulation and actual testing results indicate that this temperature control method has a faster response speed and less overshoot compared to traditional PID control, significantly improving the heating performance of MEMS TGA.

Crystal morphology prediction of CL-20 and 1,4-DNI co-crystal at different temperatures.

The morphologies of hexanitrohexaazaisowurtzitane (CL-20) and 1,4-dinitroimidazole (1,4-DNI) co-crystal under vacuum or solvent at different temperatures were predicted. The CL-20/1,4-DNI co-crystal has six important growth crystal planes: (002), (011), (101), (11‒1), (110), (111). The areas of (002), (101), and (011) planes account for a relatively large proportion, which are important crystal planes that affect the crystal morphology. The crystal habits at different temperatures were simulated. The simulation results showed that the crystal plane attachment energy of CL-20 and 1,4-DNI co-crystal increases with the increase of temperature, indicating that the increase of temperature is conducive to the growth of crystal planes. The aspect ratio decreases with the increase of temperature and the morphology of co-crystal becomes more spherical at a higher temperature. The theoretical predictions are in good agreement with the experiment. The simulation results can provide guidance for the crystallization of CL-20/1,4-DNI to obtain a nearly spherical crystal morphology. The CL-20/1,4-DNI unit cell structure was geometrically optimized by the COMPASS force field. The AE model was used to predict the morphology of CL-20/1,4-DNI under vacuum, resulting in the most morphologically important growth planes. Ethyl acetate was selected as the solvent. The interaction energy between the solvent and the crystal plane, and the attachment energies in solvent at 298 K, 320 K, 340 K, 360 K, and 380 K were predicted. The NVT ensemble is used in the molecular dynamics calculation process. The simulation step is 1 fs and the total simulation time is 500 ps. The Andersen thermostat is selected as the temperature control method. In the potential energy calculation, the atom-based and Ewald methods were selected to calculate the van der Waals force and the electrostatic interaction force, respectively.

Assessing the energy storage potential of electric hot water cylinders with stochastic model-based control

ABSTRACT As electric hot water cylinders (HWCs) have a large capacity for thermal storage, they are well-suited for Demand Side Management (DSM). This paper compares different methods of HWC temperature control and presents a methodology to assess the amount of thermal storage available in HWCs for demand side management based on use behaviour in different household types. Simple stochastic methods for domestic hot water (DHW) demand prediction were employed to design a smart controller that produced lower rates of unmet DHW demand and higher available storage than setpoint and ripple controllers. The average storage available for DSM from the use of this smart controller is predicted to be between 3.63 and 7.20 kWh per household. These results indicate the use of HWCs for thermal storage is a low-cost viable option for peak-shaving of power system load and could decrease power system greenhouse gas (GHG) emissions in countries such as Aotearoa New Zealand, where GHG-emitting electricity generation is primarily used to meet peak loads.

Integration of the PEMFC with a hydrogen production device adopting sodium borohydride and metal cobalt catalyst

Hydrolysis technology that releases hydrogen from chemical hydrogen storage materials is a method to produce hydrogen. Hydrogen storage has excellent development potential and is also one of the sources of large amounts of hydrogen. A sodium borohydride hydrogen production experiment was carried out based on steam hydrolysis technology. The system reaction tank is divided into a water-carrying bed and a catalyst bed. A mixed aqueous solution with a concentration of 1 wt% sodium hydroxide (NaOH) + 10 wt% sodium borohydride (NaBH4) was used for the hydrogen production reaction test. These experiments determined the appropriate aqueous solution and water vapor combination, and optimal parameters for hydrogen production. The hydrogen production catalyst powder, blend ratio, different steel ball ratios, and ball milling time at the steam hydrogen production end will all affect the powder's fineness and hydrogen production stability. Under catalyst temperature control, the by-products solidify at a specific temperature, which affects the gas passage and causes blockage. Increasing the hydrogen production in an aqueous solution requires a Co2+/Al2O3 catalyst, or a temperature control method to catalyze hydrogen production to obtain stable hydrogen production suitable for emergencies without hydrogen storage containers. This experiment built a hydrogen production system combined with a fuel cell for power generation testing. The test process and results indicate whether the aqueous solution and steam technology can be an effective solution when the hydrolysis hydrogen production technology is matched.

Temperature Control After Cardiac Arrest: A Narrative Review.

Cardiac arrest (CA) is a critical public health issue affecting more than half a million Americans annually. The main determinant of outcome post-CA is hypoxic-ischemic brain injury (HIBI), and temperature control is currently the only evidence-based, guideline-recommended intervention targeting secondary brain injury. Temperature control is a key component of a post-CA care bundle; however, conflicting evidence challenges its wide implementation across the vastly heterogeneous population of CA survivors. Here, we critically appraise the available literature on temperature control in HIBI, detail how the evidence has been integrated into clinical practice, and highlight the complications associated with its use and the timing of neuroprognostication after CA. Future clinical trials evaluating different temperature targets, rates of rewarming, duration of cooling, and identifying which patient phenotype benefits from different temperature control methods are needed to address these prevailing knowledge gaps.

A novel hierarchical temperature control method of an electric oven and its experimental evaluation

PurposeOvens are semi-industrial multipurpose equipment that are used to provide a desired temperature for specific chemical processes. Temperature regulation in the presence of different type of disturbances and dealing with nonlinear dynamics with large dead time (up to a few minutes) are some undesirable factors that have to be considered in the controller design procedure of the oven systems. Due to these factors, the classical PID controller tuned using Cohen-Coon or Ziegler–Nichol’s tuning methods often fails to meet satisfactory closed-loop performance.Design/methodology/approachIn this paper, to deal with the limitations on the oven system due to the undesirable factors, a hierarchical automaton-guided form controller has been designed. The proposed controller includes several discrete PI controllers, each of which operates locally in the defined operating regions whose separation idea is specific to this paper. Based on the idea proposed in the separation of regions, the controller’s coefficients tuning rules are extracted prior to any determination. Then, a supervisor controller has assumed the task of switching between local controllers. In the next step, by considering a conceptual model for the oven system and using a candidate Lyapunov function, the stability conditions of closed-loop system are discussed and the necessary conditions for the asymptotic stability are derived. The proposed controller is practically implemented with the help of the Arduino Nano platform.FindingsUsing several experiments, the superiority of the proposed hierarchical controller in terms of performance and energy consumption has been demonstrated.Originality/valueThe proposed hierarchical controller has been implemented practically and an acceptable closed-loop performance has been achieved. To illustrate the efficiency of the proposed method, the closed-loop stability of this method is shown using the Lyapunov theory.

An Advanced Fractional Order Method for Temperature Control

Temperature control in buildings has been a highly studied area of research and interest since it affects the comfort of occupants. Commonly, temperature systems like centralized air conditioning or heating systems work with a fixed set point locally set at the thermostat, but users turn on or turn off the system when they feel it is too hot or too cold. This configuration is clearly not optimal in terms of energy consumption or even thermal comfort for users. Model predictive control (MPC) has been widely used for temperature control systems. In MPC design, the objective function involves the selection of constant weighting factors. In this study, a fractional-order objective function is implemented, so the weighting factors are time-varying. Furthermore, we compared the performance and disturbance rejection of MPC and Fractional-order MPC (FOMPC) controllers. To this end, we have chosen a building model from an EnergyPlus repository. The weather data needed for the EnergyPlus calculations has been obtained as a licensed file from the ASHRAE Handbook. Furthermore, we acquired a mathematical model by employing the Matlab system identification toolbox with the data obtained from the building model simulation in EnergyPlus. Next, we designed several FOMPC controllers, including the classical MPC controllers. Subsequently, we ran co-simulations in Matlab for the FOMPC controllers and EnergyPlus for the building model. Finally, through numerical analysis of several performance indexes, the FOMPC controller showed its superiority against the classical MPC in both reference tracking and disturbance rejection scenarios.

Suitability analysis of a temperature and humidity control device using a desiccant rotor

As the amount of ventilation required in buildings has increased to prevent the spread of COVID-19, the inflow of high humidity outside air in summer has increased the processing rate of latent heat loads as well as sensible heat loads. Accordingly, the ability to handle the latent heat load with low energy consumption has become important in order to maintain a comfortable indoor environment. In this study, a humidity control device composed of a desiccant rotor was designed and manufactured, and performance experiments were performed. Using an empirical formula obtained through experiments, a thermal environment simulation was conducted for a school classroom. Furthermore, a temperature-humidity control device that combines a desiccant rotor and heat pump was proposed, and the performance and energy consumption were analyzed by comparing it with the existing heat pump design. With conventional temperature control method using a heat pump, the average indoor relative humidity values in August were 65.7 %, which exceeds the set relative humidity range of 50±5 %. On the other hand, when using the temperature-humidity control device, the average indoor relative humidity values in August was 50.2 %, a more comfortable indoor environment than when using a conventional method. In addition, the energy consumption was reduced by 3 % compared to existing heat pump design.

A Reliable Data-Driven Control Method for Planting Temperature in Smart Agricultural Systems

With the rapid development of intelligent computing technologies, the smart agricultural systems has gradually received more research attention. Precisely controlling planting conditions via intelligent means, it is expected to technically improve reliability of smart agricultural systems. For this purpose, this paper introduces the idea of big data fusion, and proposes a reliable data-driven control method for planting temperature in smart agricultural systems. Firstly, a variety of sensors are used to collect the values of environmental factors such as air temperature and light intensity during the experiment, and the “Digi” wireless communication technology is used to transmit the data. Then, the collected data is sent to the server through the 5G module, and the important data of the growth process is stored in the MySQL database. Taking the cultivation of yams as the investigation object, experiments on the real-world data are utilized to evaluate the proposal. And it is shown that the propose framework can work well to control temperature for yam planting from the perspective of data fusion.

СИНТЕЗ НЕЧІТКОГО РЕГУЛЯТОРА ТЕМПЕРАТУРИ ПАСТЕРИЗАЦІЇ МОЛОКА

The article solves the actual scientific and technical task of reducing the energy intensity of pasteurization of milk in the POU5 apparatus by means of research and development of an automated system for controlling the pasteurization temperature regime. A study of the features of the device's functioning, setting the parameters of the control process was carried out; the improvement of the mathematical model and the algorithm for regulating milk pasteurization parameters was carried out; an automated system for controlling the temperature of milk pasteurization in the POU5 installation was created. The synthesis of a fuzzy regulator of milk pasteurization temperature was carried out. Constructed response surface of milk temperature changes depending on the consumption of milk for pasteurization and the temperature of the hot water of the heat exchange r. The application of the fuzzy logic apparatus for building an adaptive system makes it possible to create adaptive systems with optimal control for the purpose of approximating the output variable of the fuzzy controller.A structural scheme of the milk pasteurizer was created, as well as effective methods of temperature control and para-metric schemes of sections (recovery, pasteurization and cooling of the plate milk pasteurizer) were developed, which allow improving the accuracy of technological process control.As a result of conducting theoretical research, a dynamic characteristic of the pasteurization section was obtained ac-cording to the channel «hot water consumption - temperature of pasteurized milk». The specified model will allow to develop temperature control algorithms to increase pasteurizer productivity

Temperature control method of CO<sub>2</sub> laser operating in airborne wide temperature range

The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed

Active temperature control method based on time grating principle for the feed system of precision machine tool and its application

Active temperature control method based on time grating principle for the feed system of precision machine tool and its application

Synthesis of wrinkle silica nanospheres by solvent evaporation-induced self-assembly method for hydrogenation reaction

Wrinkle silica nanoparticles (WSNs) possess the typical characteristics in their short diffusion path and central-radial pore structure, which are favorable to use in a wide range of practical application. In this research, a solvent evaporation-induced self-assembly strategy was adopted for the preparation of WSN materials to give an insight into the formation mechanism of the WSNs. Through one-step temperature-controlled method, it was found that the WSNs could be successfully synthesized under the temperature of 60 °C, while the pore sizes and particle sizes were both gradually decreased as the synthesis temperature continued to increase. Comparably, a two-step temperature-controlled method was employed through modulating the stirring time length in order to synthesize silica nanospheres with large pore size and small particle size. The results showed that Ni2P/WSNs-8+16 catalyst performed the highest naphthalene hydrogenation activity (almost 100% conversion at 300 °C) when the stirring time in the first stage and the second stage was 8 h and 16 h, respectively.

Characteristic Prediction and Temperature-Control Strategy under Constant Power Conditions for Lithium-Ion Batteries

Accurate characteristic prediction under constant power conditions can accurately evaluate the capacity of lithium-ion battery output. It can also ensure safe use for new-energy vehicles and electrochemical energy storage. As the battery voltage continues to drop under constant power conditions, the battery current output will accordingly increase, which brings a risk of thermal runaway in instances of weak heat dissipation. Therefore, knowing how to control the battery temperature is very critical for safe use. At present, the model-based method for characteristic prediction and temperature control has been used by most scholars, and that is also the key to this method. This work firstly extends a cell model to a pack-based electrochemical two-dimensional thermal coupling model, considering the heterogeneity of different cells inside the pack, and obtains the model parameters for a prismatic lithium-ion battery with a rated capacity of 42 Ah. Characteristic prediction under constant power conditions is then conducted based on an iterative solution method. Validations of characteristic prediction indicate the convenience of the developed models, with average absolute errors of voltage and temperature less than 36 mV and 0.4 K, respectively, and power error less than 0.005%. Finally, two model-based temperature feed-forward control strategies with lower cooling costs and shorter prediction times were developed based on the battery characteristic predictions, which leaves room for further controller development.

Simulating Temperature in a Soil Incubation Experiment

The study of warming impact on soils requires a realistic and accurate representation of temperature. In laboratory incubation studies, a widely adopted method has been to render constant temperatures in multiple chambers, and via comparisons of soil responses between low- and high-temperature chambers, to derive the warming impact on soil changes. However, this commonly used method failed to imitate both the magnitude and amplitude of actual temperatures as observed in field conditions, thus potentially undermining the validity of such studies. With sophisticated environmental chambers becoming increasingly available, it is imperative to examine alternative methods of temperature control for soil incubation research. This protocol will introduce a state-of-the-art environmental chamber and demonstrate both conventional and new methods of temperature control to improve the experimental design of soil incubation. The protocol mainly comprises four steps: temperature monitoring and programming, soil collection, laboratory incubation, and warming effect comparison. One example will be presented to demonstrate different methods of temperature control and the resultant contrasting warming scenarios; that is, a constant temperature design referred to as stepwise warming (SW) and simulated in situ temperature design as gradual warming (GW), as well as their effects on soil respiration, microbial biomass, and extracellular enzyme activities. In addition, we present a strategy to diversify temperature change scenarios to meet specific climate change research needs (e.g., extreme heat). The temperature control protocol and the recommended well-tailored and diversified temperature change scenarios will assist researchers in establishing reliable and realistic soil incubation experiments in the laboratory.

Experimental Investigation into the Effect of Fin Shapes on Heat Dissipation Performance of Phase Change Heat Sink

In this paper, the thermal management of missile-borne components in a flight state is studied. Avoiding excessive component temperatures under the high-temperature circumstances brought by aerodynamic heat is a requirement to guarantee the equipment’s safe and reliable operation. In this work, we designed four finned shell constructions for a phase change module using the phase change temperature control method and then studied their effects on the module’s ability to dissipate heat using an experimental approach. Three sizes of 30 mm, 40 mm, and 50 mm heating pads were used to replicate heat sources with various heat flux densities and heat dissipation regions, with reference to the heating characteristics of various chips. The results demonstrated that the square-shaped fin had the best heat dissipation effect after operating for 10 min under the power of 10 W and 20 W, while the strip-shaped fins exhibited the highest performance under the power of 30 W. The square-shaped fins had the best heat dissipation effect when reducing working time to 5 min. This paper proposes the optimal fin scheme under different power densities, as well as an enhanced heat dissipation idea for the melting process of the phase change materials based on the test results.

Recent advances and challenges in temperature monitoring and control in microfluidic devices.

Temperature is a critical-yet sometimes overlooked-parameter in microfluidics. Microfluidic devices can experience heating inside their channels during operation due to underlying physicochemical phenomena occurring therein. Such heating, whether required or not, must be monitored to ensure adequate device operation. Therefore, different techniques have been developed to measure and control temperature in microfluidic devices. In this contribution, the operating principles and applications of these techniques are reviewed. Temperature-monitoring instruments revised herein include thermocouples, thermistors, and custom-built temperature sensors. Of these, thermocouples exhibit the widest operating range; thermistors feature the highest accuracy; and custom-built temperature sensors demonstrate the best transduction. On the other hand, temperature control methods can be classified as external- or integrated-methods. Within the external methods, microheaters are shown to be the most adequate when working with biological samples, whereas Peltier elements are most useful in applications that require the development of temperature gradients. In contrast, integrated methods are based on chemical and physical properties, structural arrangements, which are characterized by their low fabrication cost and a wide range of applications. The potential integration of these platforms with the Internet of Things technology is discussed as a potential new trend in the field.