Chapter 9 - Case Study: Temperature control project

In industrial production, temperature and humidity are common main manipulated parameters, especially in heat treatment industry, the temperature control is becoming more and more important. This paper from two aspects that hardware and software introduced single-chip microcomputer (SCM) C8051F intelligent temperature and humidity control system, and described schematic diagram of hardware and software. The design adds the integration of carbon dioxide concentration and light intensity detection and necessary communication function. It is a more humanized and more practical intelligent temperature and humidity measurement and control system.

The design and verification of accurate temperature control system of the oven with the small or middle scale programmable logic controller (PLC) base on the dahlin algorithm is introduced. The design can achieve accurate control to the pure lag system and regulate the other logic control form the same controller. The system is cost-effective on the specific modular or instrument for the complex computing in some automatic device. Meanwhile, the design is computed and simulated by the matlab softwear for verifying the implementation. DOI: http://dx.doi.org/10.11591/telkomnika.v11i8.3101

Aiming at the problems of low degree of intelligence and insufficient remote interaction ability of the traditional electric control box temperature control system, this study designs and implements an intelligent temperature control system based on STM32 microcontroller for the Internet of Things (IoT). The system adopts a multi-channel sensor fusion scheme, through the fixed point of multiple DS18B20 temperature sensors to build a distributed temperature measurement network, combined with the sound to determine the equipment failure method to achieve the intelligence of the temperature control system. A dual-channel power driver module was designed at the hardware level, with cooperative control of the heat source power and the AC fan. At the software level, an IoT architecture based on MQTT protocol was developed to realize real-time uploading of data to the built cloud platform and remote interaction through mobile APP to realize temperature regulation and control in the electric control box. The fan speed and the power of the heat source are adjusted in time according to the change of temperature in the real-time temperature control cabinet to ensure that the temperature in the temperature control cabinet remains constant. The content of this study helps to provide assistance in designing temperature control systems in the Internet of Things.

In this article, the new method for designing the temperature control system with low vibration for a scanning tunneling microscope using dual modes heat exchanging process is proposed. The system is designed to operate into two modes i.e. the temperature control mode and the temperature stabilization mode. In the temperature control mode, the cold water is used as a heat convector in heat exchanging process. To reduce the vibration introduced by flowing of water in heat exchanging process, the cold vapor is used as a low density heat convector in the temperature stabilization mode. To assess the feasibility of the new proposed method, the preliminary experimental system is setup and verified. The experimental result of temperature control with step changed of the set-point temperature shows that temperature inside the cylindrical closed surface capsule reached the set-point value with the rise time of 25 min. The experimental result also shows that temperature stability with the fluctuation level of 0.05 °C and 0.01 °C over periods of 15 min and 2 min, respectively, are achieved. The results indicate that our goal to construct the temperature control system for a scanning tunneling microscope with temperature fluctuation of 0.01 °C over a period of 1 hour and low vibration can be realized by using the proposed method.

With the development of science and technology in China, temperature control system has been widely used in many fields. The emergence of PLC effectively improves the shortcomings of PID control system, optimizes the performance of PID control system, and plays a very important role in promoting industrial production and construction. In view of the design of temperature control system of heating furnace, configuration software and PLC can be used the combination of technology can achieve the goal of furnace temperature control, and it can also monitor the furnace temperature in real time and comprehensively, and then adjust the furnace temperature according to the application requirements. The investment in the process is less, which can reduce the cost to a certain extent, and also has the application advantage of high accuracy. The temperature control system of electric heating furnace is designed in this paper. PLC is mainly used, and the temperature system is controlled intelligently with touch screen. According to the actual situation and cost budget, the controller of this paper chooses Mitsubishi FX2N- 48MR series PLC. In order to achieve intelligent control, it needs to use digital PID control algorithm, which is convenient for the staff to operate Gt1040-qbbd-c series touch screen is used to realize human-computer interaction. The system can be started and stopped. The touch screen for temperature setting can be very simple to operate. The temperature change can also be visually displayed and monitored, and the whole system can be automatically set.

The temperature control and monitoring system in the freezer room has an important role in maintaining the quality of food raw materials. Freezer space is used to store food raw materials to keep them fresh and undamaged. However, if the temperature in the freezer compartment is not properly monitored, food raw materials may be damaged which can affect their quality and safety. Therefore, an IoT-based temperature control and monitoring system in the freezer room was created using Wemos D1 R2. The design of this prototype uses hardware, namely the WeMos D1 R2 microcontroller based on ESP8266 because it can be connected to WiFi, DHT22 temperature sensor, I2C LCD and relay. The results of this prototype design are being able to read the temperature and humidity of the freezer room and having a temperature control system that can be seen on the Blynk application on a smartphone by displaying the temperature and humidity values. The conclusion from this study is that the prototype has succeeded in controlling the temperature of the freezer room as well as monitoring the temperature and humidity of the freezer room and displaying it on the Blynk application on a smartphone and has a warning notification when the temperature rises above -18 degrees celsius.

To solve the problem in which the output power and wavelength of semiconductor lasers in fiber optic sensing systems are easily affected by the drive current and temperature, a high-precision current drive and temperature control system was developed in this study. The embedded system was used to provide a stable drive current for the semiconductor laser through closed-loop negative feedback control; moreover, some measures, such as linear slow-start, current-limiting protection, and electrostatic protection, were adopted to ensure the stability and safety of the laser’s operation. A mathematical model of the temperature control system was constructed using mechanism analysis, and model identification was completed using the M sequence and differential evolution (DE) algorithms. Finally, the control rules of the fuzzy proportional integral differentiation (PID) algorithm were optimized through system simulation to make it more suitable for the temperature control system designed in this research, and the accurate control of the working temperature of the semiconductor laser was realized. Experimental results showed that the system could achieve a linearly adjustable drive current in the range of 0–100 mA, with an output current accuracy of 0.01 mA and a temperature control accuracy of up to 0.005 °C.

Electrical vs solar water heater: A case study

To solve the problem of large electric energy consumption of household electric water heater (EWH), firstly, an electric water heater model considering demand response is established, and an improved electric water heater optimization control strategy based on binary particle swarm optimization (BPSO) algorithm is proposed with time-of-use price as incentive, so that the load of electric water heater directly responds to the incentive signal sent by power grid company, By changing its own running state and energy consumption to achieve the optimization goal. Numerical simulation results demonstrate the effectiveness of the proposed strategy.

The paper represents the mathematical model for diagnostics of the corrosion protection potential for the electric water heaters (EWH). The research objectives are the problem of determining the EWH corrosion protection technical condition during its operation. The EWH corrosion protection diagnostics is based on the mathematical model of the corrosion protection potential for EWH. The model is based on the nonlinear equivalent circuit which is modelling the nonlinear impedance of the corrosion cathodic protection. In the development of the mathematical model the authors carried out experimental measurements of the impedance for the EWH body fragment. The obtained experimental results show that mathematical model includes the fractional integrating elements. By using of the experimental results the expressions of the impedance, the impulse response is obtained. The methodological approach to increasing the reliability of the EWH corrosion protection diagnostics has been proposed, in terms of the multi-parameter diagnostics, by applying the EWH corrosion protection impedance model.

The performance parameters and long-term operation stability of the photodetector in radiation temperature measurement will change with the change of working temperature. In order to meet the high precision temperature control demand of the photodetector, a temperature control system based on the thermoelectric refrigeration control chip ADN8831 is designed. The control system uses the thermistor as the temperature sensing element, and uses the analog proportional integral differential (PID) circuit to control the temperature closed-loop. The experimental results show that the Thermoelectric cooler (TEC) inside the photodetector can stabilize at the set temperature within 11 s under the drive of the temperature control system, and the temperature control accuracy is as low as ± 0.01 °C.

Microfluidic Lab on a Chip (LOC) devices are key enabling technologies for research and industry due to their compact size, which increases the number of integrated operations while decreasing reagent use. Common operations within these devices such as chemical and biological reactions, cell growth, or kinetic measurements often require temperature control. Commercial temperature controllers are constrained by cost, complexity, size, and especially versatility for use in a broad range of applications. Small companies and research groups need temperature control systems that are more accessible, which have a wide applicability. This work describes the fabrication and validation of an inexpensive, modular, compact, and user-friendly temperature control system that functions within a microscope. This system provides precise temperature acquisition and control during imaging of any arbitrary sample which complies with the size of a microscope slide. The system includes two parts. The first part is a compact and washable Device Holder that is fabricated from high-temperature resistant material and can fit securely inside a microscope stage. The second part is a robust Control Device that incorporates all the necessary components to program the temperature settings on the device and to output temperature data. The system can achieve heating and cooling times between 50 °C and 100 °C of 32 s and 101 s, respectively. A Bluetooth enabled smartphone application has been developed for real-time data visualization. The utility of the temperature control system was shown by monitoring rhodamine B fluorescence in a microfluidic device over a range of temperatures, and by performing a polymerase chain reaction (PCR) within a microscope. This temperature control system could potentially impact a broad scope of applications that require simultaneous imaging and temperature control.

A single electric water heater’s physical model based on first-order constant coefficient differential equations is constructed in this paper. An electric water heaters’ polymerization model is constructed based on the Monte Carlo method, and the error analysis is performed on the polymerization model. The influence of changing conditions on the frequency regulation response of the demand side of electric water heater is analyzed. The simulation results show that the electric water heaters can respond to changes in the frequency of the power system by adjusting their temperature setting point to provide a consider-able amount of frequency backup capacity.

In order to ensure the measurement accuracy and long-term working stability of the laser methane sensor in the field environment such as coal mines, a design method of a high-precision double-closed-loop laser temperature control system based on the laser absorption peak and working temperature is proposed to improve the temperature control system of the DFB laser. control accuracy. Based on ADN8834 integrated TEC controller chip, the temperature control system based on PI compensation network is designed, and the simulation analysis of the temperature control system is carried out. In order to verify the accuracy and long-term working stability of the temperature control system, the laser methane sensor has passed the (-20~60)℃ high and low temperature experiment. The application of methane sensors in industrial sites such as coal mines provides technical support.

<div class="htmlview paragraph">Unique challenges arise during the design of temperature and humidity control systems (THCS) for use in microgravity. The design of the Plant Research Unit’s (PRU) THCS builds on the experience gained during the Biomass Production System (BPS) project and extends the understanding of the critical design variables and necessary technical advancements to allow for longer on-orbit operation. Previous systems have been limited by loss of prime, clogging in the porous plates and component reliability. Design of THCSs for long-duration space flight experiments requires the mitigation of these issues as well as a complete understanding of the relevant design variables. In addition to the normal design variables (e.g. mass, power, volume), a complex and interdependent relationship exists between the THCS variables including operational temperature range, operational humidity range, required humidity condensation rate and system air flow.</div>