Temperature Control Method Research Articles

Strength and Deformation Responses of Biocemented Sands Using a Temperature-Controlled Method

AbstractThe strength and deformation responses of sands improved by a temperature-controlled biotreatment method were investigated through a series of drained triaxial compression tests under vario...

Understanding and Practice of Room Temperature Control Method Based on Energy Saving Reconstruction of Public Buildings

In order to respond to national energy conservation and environmental protection policies, green building development strategies should be implemented in urban public buildings construction, and large-scale project energy-saving renovation plans should be implemented from the perspective of energy conservation. Different projects can adopt different energy-saving control methods according to actual conditions and adopt different control strategies, but the ultimate goal is to change the current situation of large energy consumption, high utilization efficiency, noise pollution, water pollution and air pollution emissions. Building energy-saving renovation and technical control, effectively improves the building energy-saving level, achieves energy-saving and consumption-reduction goals, and gives full play to the value of various resources. At the same time, the energy-saving renovation project can also help enterprises to obtain the maximum economic and social benefits and promote the sustainable development of the construction industry. In view of this, this paper will talk about how to achieve energy-saving goals in the energy-saving renovation of public buildings from the aspects of energy-saving design of indoor supporting facilities, energy-saving design of walls, energy-saving design of doors and windows and roofing energy-saving design, and how to achieve reasonable control of room temperature.

Practical Nozzle Temperature Control Method for Robot FDM Printing System

Fused Deposition Modeling (FDM) technology in 3D printing has beendeveloped for many years. In this paper, a robot FDM 3D printingsystem is proposed and the nozzle temperature control issue isfocused primarily. The temperature measurement adopts a data driven modeling method andthe parameters of the measurement model are trained by the particle swarm optimization algorithm. A practical temperature control method is presented in which thetemperature control of nozzle is divided into two periods. Duringthe temperature flying period, the heating voltage is givenaccording to the current temperature value and its varying trend. In thefalling time of nozzle temperature, the corresponding controlvoltage value is provided correspondingly. Based on this practical control strategy, a partdesigned with Solidworks software is printed using the robot FDM printing system which validates theeffectiveness of the practical temperature control method.

A Novel Algorithm to Differential Scanning Calorimeter Temperature Control Based on Liquid Nitrogen Feedforward Technique

Differential scanning calorimeter (DSC) is an important instrument in the thermal analysis which could be pervasively applied to property analysis of inorganic compounds, organic compounds and drugs. An effective temperature control technique could ensure DSC thermal experimental accuracy. Unlike the traditional temperature control methods which have limited temperature control ranges and change rates, this paper presents a novel algorithm which exploits the liquid nitrogen feedforward technique to control the temperature of DSC. To be specific, the proposed approach fully takes advantage of the characteristic of the liquid nitrogen that has the ability to rapidly decrease the objective temperature. Furthermore, a cold-heat synergistic feedforward-feedback control is utilized. On one hand, the feedforward controller is able to avoid the singularities for the amount of liquid nitrogen. On the other hand, the feedback controller is able to compensate for the temperature errors due to external disturbances. The proposed algorithm has been applied to the DSC. The experimental results and analysis prove that the control method is able to change the temperature accurately within a wider range.

Design and Implementation of Temperature Control for a Mini-chamber using Self-Tuning PID Controller

Despite its popularity in industrial application, PID controller suffers parameters setting difficulty due to set point change, disturbance, and ageing. This paper proposed Self-tuning PID controller using Dahlin method for temperature control of a laboratory scale mini-chamber. Experimental results show that the proposed controller has better performance compared to the conventional PID controller in term of rise time and settling time. It also shows that the algorithm can compensate the changing environment and robust toward the existence of disturbance.

Control methods for a direct-ground cooling system: An experimental study on office cooling with ground-coupled ceiling cooling panels

This article experimentally investigates the performance of two control methods (the supply water temperature method and the water flow control method) for a direct-ground cooling system. The control methods were implemented through three types of indoor feedback controllers: 1) an on/off controller, 2) an on/off controller with a deadband and 3) P controller. The performances of the control methods were evaluated regarding room temperature stability and pump energy use. Ceiling cooling panels were employed to keep the test room air temperature at 25.0 °C under periodic heat gain conditions. The cooling system used a ground heat exchanger with a U-pipe in an 80-meter-deep borehole as a cooling source. The findings show that room air temperature was maintained close to the set-point with both control methods, but it was more stable with the temperature control method. In addition, condensation risk was easily preventable with the temperature control method. A parametric study showed that pump energy use when using two-position controllers could be as low as when using modulating controllers if the on-state flow rate of the circulating pump is selected in relation to the ground temperature and heat transfer characteristics of the heat exchanger.

A Thermoelectric Device for Coupling Fluid Temperature Regulation During Continuous Skin Sonoporation or Sonophoresis.

During skin sonoporation and sonophoresis, time-consuming duty cycles or fluid replacement is often required to mitigate coupling fluid temperature increases. This study demonstrates an alternative method for temperature regulation: a circulating, thermoelectric system. Porcine skin samples were sonoporated continuously for 10min at one of three intensities (23.8, 34.2, 39.4W/m2). A caffeine solution was then applied to the skin and left to diffuse for 20h. During sonoporation, the system was able to maintain the temperature between 10 and 16°C regardless of the intensity. No increase in transdermal transport was achieved with an intensity of 23.8W/m2. Intensities of 34.2 and 39.4W/m2 resulted in 3.5-fold (p< 0.05) and 3.7-fold (p< 0.05) increases in mean transport, relative to a control case with no ultrasound. From these results, it is concluded that a significant transport increase can be achieved with a system that circulates and cools the coupling fluid during ultrasound application. Relative to the previous methods of temperature control (duty cycles and fluid replacement), use of this circulation system will lead to significant time savings in future experimental studies.

Molecular dynamic simulation of bubble nucleation in a nanochannel with a groove

Molecular dynamics methods are used to investigate the effect of wall wettability and initial fluid density on the nucleation and growth of nanobubbles in a nanochannel with a groove. Surface wettability is controlled by adjusting the parameters of the solid-liquid potential energy and the results show that groove wettability greatly influences the bubble nucleation process. In the case of a groove with a weak solid-liquid interaction, fluid atoms in the groove are strongly affected by repulsive forces attributed to solid atoms, the density of the fluid atoms is low, and atomic collision frequency increases. The local activation energy is concentrated in the groove, resulting in bubble nucleation. In the case of a groove with a stronger solid-liquid interaction, the bubble is formed in the center of the nanochannel. In general, the bubble radius of curvature and contact angle remain unchanged during the growth process in the case of a uniform wettability nanochannel with a groove, while significant changes are observed for a nonuniform wettability nanochannel. The radius of curvature for the generated bubble increases with increasing fluid initial density, while the steady contact angle decreases. At the request of the authors this paper is being retracted. This action is taken because in the simulation cases of β=0.3 and β=0.4, the temperature control method is incorrect, resulting in flawed simulation results in Figs. 8 and 9. In addition, the number of atoms (and hence the density) in the simulation box is also not correct due to errors in the initialization phase of the simulation. Thus, the calculated phase diagram in Fig. 2 is incorrect. The authors sincerely apologize for these errors and omissions and regret any inconvenience they may have caused.

Temperature control of fermentation bioreactor for ethanol production using IMC-PID controller

The state-space model is identified using the identification tool of MATLAB, and the best fit of 99% of measured and simulated data was obtained. Further, state-space model was converted to a transfer function model and finally simplified to an unstable second order time-delay transfer function model. Internal model control based proportional integral derivative (IMC-PID) controller design method was proposed for unstable second order time delay with RHP zero (USOPDT) and successfully tested to the nonlinear bioreactor process model. The temperature of the bioreactor was successfully controlled by proposed controller in both cases setpoint and disturbance change. The performance of the controller was evaluated in terms of IAE, ISE, ITAE and the corresponding values of 20.99, 49.02 and 292.50 were obtained respectively. Proposed method shows better closed-loop performance in terms of IAE and settling time than the other reported methods for temperature control of bioreactor.

Research and design of semiconductor laser temperature stabilization system in laser system

The power output stability of semiconductor laser in the laser system is closely related to the working temperature. As the control precision is not high and control speed of temperature control system is slow in the laser system, this paper discusses a new temperature stabilization system. This system gets laser temperature by PT-100 temperature sensor, and uses the least squares fitting to process the temperature data, thus to ensure the temperature measurement accuracy of 0.01 ℃. And the system adjusts the temperature by PID controller whose parameter is optimized by particle swarm optimization algorithm. Simulation experiments and actual test show that of the temperature system can quickly stabilize the temperature of laser, the time of adjustment is less than 11 s. And the fluctuations of temperature is about 0.02 ℃ after the system reaching the steady state. Compared with the traditional temperature control method, the system can achieve self-tuning of parameters and automatically adjust the temperature, the laser temperature in the high-power laser system has a good stability.

Application of Titanium Dioxide (TiO₂)-Embedded Buoyant Photocatalyst Balls Using Expanded Polystyrene.

A new immobilization technique of nanoscale TiO₂ powders to expanded polystryrene (EPS) balls with temperature-controlled melting method was validated for mass production, and the photocatalytic activity of TiO₂ powder-embedded EPS (TiEPS) balls using methylene blue (MB) solution with different concentrations under ultraviolet irradiation and under the natural solar light irradiation. Whereas MB molecules were weakly adsorbed onto the surface of both TiO₂ powders and supporting polymers without any specific interactions, the photocatalytic efficiency of TiEPS balls with UV (Kapp =0.016~0.043 min-1) was greater through coupled reaction processes (adsorption, photolysis, and photocatalysis). After 5-min sonication, more TiO₂ powders on the TiEPS balls can be involved into the both adsorption and photocatalytic reactions of MB, and can increase the MB removal efficiencies. TiEPS balls can be reused for several consecutive runs without any significant decrease in photocatalytic activity until the recalcitrant contaminants were completely coated on the surface of TiEPS balls and loss of TiO₂ powders embedded on the surface of TiEPS balls was significant. Based on the aforementioned results, self-floating TiEPS balls manufactured from this simple and cost-effective melting method can be used to remove the organic contaminants and to inhibit the excessive growth of harmful algae in the stagnant water body.

Study on cooling down law and temperature control method of liquid blast furnace slag storage device from energy saving of steel industry

The metallurgical industry is a typical energy-intensive industry, whose energy-saving potential is enormous. Liquid blast furnace slag temperature is about 1400 °C, and its volume is large and discharged discontinuously. Existing technologies, using boilers and steam turbine to recover the waste heat, need to be carried out continuously. To solve the bottleneck of mismatch between intermittent slagging and waste heat continuous recovery, this paper discussed the liquid slag storage and temperature control device referring to the liquid metal buffer device such as ladle and tundish. Then, the heat transfer process and temperature distribution of the liquid blast furnace slag at different baking temperatures were numerically simulated by using the solidification-melting model. The effects of different baking temperature and slag residence time on the temperature distribution of slag were analyzed. The optimum baking temperature was obtained. The slag solidification crust phenomenon was overcome, so that slag can maintain a high-temperature level to facilitate its subsequent waste heat recovery and resource utilization.

Temperature control of a PCM integrated open-air swimming pool in cold season: a numerical and experimental study

In a conventional swimming pool temperature control, the return water temperature is considered as the representative temperature of the swimming tool rather than the average temperature although the latter is more representative regarding to thermal comfort. This is because the average temperature is difficult to measure. This paper uses field data to identify a relationship between the average and the return water temperature and develops a temperature control method based on this relationship. This control method is applied to an open-air swimming pool, for which the heat is supplied from a PCM storage tank. Numerical study, which is resorted to a simulation platform constructed using TRNSYS and MATLAB, is used to analyze the control performance of the new method and demonstrate its effectiveness by comparing with the conventional control.

A precision temperature control approach for piezoelectric jet dispenser

Jet dispenser is widely used in LED (light emitting diode), microelectronic and optoelectronic packaging field. Temperature fluctuation of adhesives is a significant factor which affects the consistency of jet dispenser. As the working condition of jet dispenser is variable, the traditional PID temperature control method cannot meet requirements of high precision dispensing. A new temperature control system is designed for a proposed jet dispenser. Fuzzy PID temperature control approach is applied in the system. Temperature fluctuation is decreased from ±3.2 to ±1.1 °C with the new system. The jetting performance will be improved with the temperature control approach.

TherMouseDuino: An affordable Open-Source temperature control system for functional magnetic resonance imaging experimentation with mice

IntroductionFunctional magnetic resonance imaging (fMRI) is one of the most highly regarded techniques in the neuroimaging field. This technique is based on vascular responses to neuronal activation and is extensively used in clinical and animal research studies. In preclinical settings, fMRI is usually applied to anesthetized animals. However, anesthetics cause alterations, e.g. hypothermia, in the physiology of the animals and this has the potential to disrupt fMRI signals. The current temperature control method involves a technician, as well as monitoring the acquisition MRI sequences, also controlling the temperature of the animal; this is inefficient. MethodsIn order to avoid hypothermia in anesthetized rodents an Open-Source automatic temperature control device is presented. It takes signals from an intrarectal temperature sensor, as well as signals from a thermal bath, which warms up the body of the animal under study, in order to determine the mathematical model of the thermal response of the animal. ResultsA Proportional-Integral-Derivative (PID) algorithm, which was discretized in an Arduino microcontroller, was developed to automatically keep stable the body temperature of the animal under study. The PID algorithm has been shown to be accurate in preserving the body temperature of the animal. ConclusionThis work presents the TherMouseDuino. It is an Open-Source automatic temperature control system and reduces temperature fluctuations, thus providing robust conditions in which to perform fMRI experiments. Furthermore, our device frees up the technician to focus solely on monitoring the MRI sequences.

Method of Temperature Control and Its Validation for Atomic Clock Cabin on Navigation Satellite

原子钟是导航卫星的重要组成部分，可为卫星系统提供高准确及高稳定度的时间频率源.原子钟工作性能与环境温度变化密切相关，为保证其在轨连续、稳定运行，热控系统需为其提供良好的工作温度环境.本文以某导航卫星原子钟舱温度控制为研究内容，给出原子钟舱热控设计方案、控制算法，并进行仿真分析和试验验证.在轨遥测数据表明，卫星原子钟舱热控方案和控制算法设计合理，仿真分析及试验结果有效，各原子钟在轨工作温度满足要求，原子钟温度稳定度满足并优于设计指标近一个数量级.

Methods for Investigating TRP Channel Gating.

A complete characterization of temperature -and voltage-activated TRP channel gating requires a precise determination of the absolute probability of opening in a wide range of voltages, temperatures, and agonist concentrations. We have achieved this in the case of the TRPM8 channel expressed in Xenopus laevis oocytes. Measurements covered an extensive range of probabilities and unprecedented applied voltages up to 500mV. In this chapter, we describe animal care protocols of patch-clamp pipette preparation, temperature control methods, and analysis of ionic currents to obtain reliable absolute open channel probabilities.

Study on Temperature Control and Crack Prevention of Mass Concrete for Large Powerhouse Constructed in Cold Area

Due to complex structure, large scale, and cold climate, the temperature field and stress field during construction of BoYi Station is different with ordinary mass concrete. Therefore the corresponding crack prevention method must be explored. In order to simulate the complicated construction course, cold climate, multiple materials and unusual structure, a finite element program is adopted. In 5 numerical simulation cases, different temperature control methods are tried to decrease the tensile stress of mass concrete. Based on the simulation analysis and combined with the engineering experience, the scheme and indexes of temperature control and crack prevention are recommended. The mainly measures are controlling pouring temperature, insulation of concrete surface, pipe cooling, block partition and extra steel bar reinforcement. The values of temperature indexes are sharply lower than that of ordinary hydropower station mass concrete. The suggested measures and indexes in this paper, which are various with season, structure position and material, may provide some reference to similar large hydropower station workshop in cold area.

Контроль температуры обмоток и защита от перегрева электрических машин переменного тока

The paper reviews and analyzes basic methods of alternating current electric machines (EM) windings temperature control, such as thermometer methods, resistance and embedded thermocouples set out by GOST 11828–86. It also reviews indirect control methods based on the direct measurement of other physical quantities functionally related to the desired value, and computational control methods, based on mathematical modeling of the unit heating process using thermal equivalent circuits. The paper shows that the most appropria­te EM winding temperature control method is the resistance method based on the principle of the conductor resistance – temperature dependence, which uses the EM winding as a thermal sensor. However, the EM windings thermal control problem has not been fully resolved and requires new principles for the construction of operational heating control systems. The paper suggests new method of the in-operation EM windings heating control, which does not require disconnecting from the network or disrupt the normal mode of operation. The method is based on the use of phase relationships between measured values as an additional informative parameter. The physical effects underlying this method are analyzed, the necessary operational implementation procedure is described. It is shown that the proposed temperature control method may serve as a convenient basis to build a thermal protection system, which can be in use both in the EM shutdown and in the control signaling modes. The paper also presents the results of the experimental test of the device based on the suggested method.

Application of Siemens PLC in Thermal Simulator Control System

In this paper, Siemens PLC controller, new generation SINAMICS V90 PN servo control system and real-time communication technology are used to design a control system of the thermal simulator for closed-loop control tasks in thermal simulation control systems. The hardware configuration, communication structure, allocation of closed-loop control tasks, data acquisition mode and logic control system of the system are introduced, and through the specific control process, the main controller S7-400CPU cooperates with the FM458 controller to complete the hammer position control, the temperature control methods of the direct resistance heating method and the induction heating method, and the method and characteristics of the real-time communication between the main controller and the S7_1200PLC to control the SINAMICS V90 PN servo motor to realize deformation displacement control are focused on