Design of Water Temperature Stabilizer Using Element Peltier and Atemga16 for Louhan’s Aquariums

This study aims to design a water temperature stabilizer in the louhan fish aquarium by using a cooling system based on a Thermoelectric Cooler (TEC) or a Peltier element. The system is built using several tools including a DS18B20 temperature sensor, a relay circuit and 3 Peltier elements. and AVR microcontroller. Temperature control is done by comparing the desired temperature set-point with the temperature from the sensor. The test was carried out by stabilizing the water temperature with two conditions, namely running water and inot flowing water and observing the behavior of the fish while the stabilizer system was running. The working principle of the stabilizer is that the sensor will read the water temperature, then the data is processed on the microcontroller. The temperature data will be compared with a predetermined set-point value which is around 29°C. If the temperature is more than 290C, then the cooler will turn on. The on-off control signal is generated by the microcontroller to turn on the relay and cooling system. From the test results obtained, the tool is able to stabilize the temperature of 290C and shows the behavior of fish with good conditions.

A portable calorimeter for measuring the calorific value of natural gas

Natural gas quality assessment is a relevant issue. A critical analysis of calorimeter designs for measuring the calorific value of natural gas was carried out. The most common methods for determining the calorific value of natural gas are as follows: direct by gas calorimeters; indirect by gas chromatographs; indirect, based on correlations. The advantages of isoperibolic calorimeters of measuring calorific value of natural gas directly in the consumer’s conditions are substantiated. The design of a portable calorimeter containing a thermostated shell, calorimetric tank, Peltier element with tank, circulating pump, gas burner, thermostat systems, metered supply of natural gas and air, fuel ignition, sensors, combustion analyzer and control and measurement unit, was developed. The geometric dimensions of the calorimetric tank are optimized, materials and technologies of manufacturing parts are specified. The metrological analysis of the developed portable calorimeter was carried out. A method for measuring the calorific value of natural gas directly in the conditions of household consumers and transport enterprises was developed. The results of testing the prototype calorimeter in the laboratory confirmed its high performance and metrological characteristics, and the deviation of the measurement of the calorific value of natural gas from that determined using a gas chromatograph was 0.6%.

Fabrication of Instant Water Cooler Using Thermoelectric Module

Hot and cold water is always needed for human being and we use different systems to get hot and cold water. The devices which are available in market for heating and cooling purpose have more costly and heavy like refrigerator, electric heater and solar water heater. So, we decide to make project on “fabrication of instant water cooler using thermoelectric module to get cold water and hot water at same time.” Peltier effect is used to get cold as well as hot water at same time with cheapest cost and applicable to use in residential area also. Our aim is toward developing a system which will provide cooling and heating effect at same time without moving mechanical parts. Thermoelectric cooling and heating system not require working fluids. This device can be used to cool water without refrigerants. And simultaneously heating can be achieved from the hot side of thermoelectric module to heat the water, this because of heat absorption and rejection using Peltier element. This compact design is very useful in elimination of CFC and it would replace refrigeration system.

Computer 2D modelling of a micro-grip fluid cooling system

Представлено компьютерное численное моделирование системы жидкостного охлаждения камеры микрозахвата. Построены математические модели течения жидкости, переноса тепла жидкостью, теплообмена между жидкостью и радиатором, теплообмена между радиатором и элементом Пельтье. Определено влияние геометрических и физических параметров камеры микрозахвата на эффективность системы охлаждения, а также найдена зависимость максимальной температуры, установившейся на радиаторе, от скорости течения охлаждающей жидкости и коэффициента теплопередачи между радиатором и жидкостью для стационарного течения. Проведено исследование влияния нестационарного течения жидкости на колебания температуры радиатора. На основе результатов численного моделирования предложены простые аналитические формулы, которые можно использовать в программном обеспечении системы управления микрозахватом Numerical simulation of a micro-grip chamber fluid cooling system is presented. The mathematical models for mass and heat transfer in a fluid, heat exchange between the fluid and the radiator as well as the heat exchange between the radiator and the Peltier element are constructed in a variational form. The equations of hydrodynamics and heat equations were simulated by the finite element method in the FreeFem++ software. The influence of the geometric and physical parameters of the cooling system chamber on the efficiency of the device is determined. It is shown that as the heat transfer coefficient between the radiator and the fluid and the velocity of the coolant increases, the maximum steady-state temperature on the radiator nonlinearly decreases with saturation. When flow of coolant oscillates then the temperature on the radiator so does with the flow frequency. As the flow frequency increases, the amplitude of temperature fluctuations decreases. The increasing amplitude of flow oscillations leads to the amplification of the temperature amplitude. Using orthogonal central compositional method, the influence of the parameters (heat transfer coefficient, fluid velocity) on the efficiency of the cooling system is found, and the contribution of pairwise interaction is determined. Based on the results of numerical modelling, simple analytical formulas are proposed that can be used in the software module of the micro-grip cooling control system.

DEVELOPMENT AND RESEARCH OF OPERATING MODES OF AN AUTONOMOUS THERMOREGULATION SYSTEM FOR THE TRANSPORTATION OF SMALL-SIZED CARGO

The article briefly discusses the possibilities of using quadrocopters for the delivery of various goods and provides examples of companies engaged in development in this area. For the practical implementation of cargo delivery, a portable autonomous module was implemented, capable of maintaining a set temperature for a certain time. The best option is to use the Peltier element for cooling, as it is quite compact. Key words: quadrocopters, cargo delivery, organization of delivery, container for cargo delivery, peltier element.

USE OF THERMAL PROCESSES TO OBTAIN ELECTRICITY

As a result of the analysis of the research results, it is easy to see that the voltage at the output of our electrothermal generator increases with increasing temperature difference between the surface of the heating system pipe and the aluminum air cooling radiator, between which are Peltier elements. However, the efficiency of such a generation is much lower than the efficiency indicated in the development guides of the corresponding model of the Peltier element (Appendix B). The reason for this is, obviously, the negative impact of the applied structural elements of the created model, which reduce the efficiency of heat transfer between the source of the temperature difference and the Peltier element. The step-up voltage converter used in the created model allows to receive necessary for power supply of useful devices of 5 V of a voltage on an output of the generator, but according to the parameters, this device needs a certain (though rather small) voltage on the input. In the study without load, we were able to obtain at the output of the converter 5 V standard voltage at a temperature difference ΔT = 16.1 ° C. Instead, in the second study, when the output of the converter was used as a source for the cooling fan, the required 5 V was achieved only at ΔТ = 23.2 ° С. This temperature difference is easily achieved by the surface of the heating radiator and the air of the living space during the heating season. That is, a generator based on four Peltier elements TPP 1 - 12706 will really be able to produce the required amount of electricity to power useful devices and charge mobile devices. Of particular interest is the result of a study of the efficiency of active air cooling, powered by the output of our generator. As we can see, the voltage at the Peltier elements under the conditions of the current at the generator output (Fig. 4, dependence 4) is noticeably lower than that in the case of the no-load experiment (Fig. 4, dependence 1). But only until the step-up converter can provide a voltage of 5 V (Fig. 4, dependence 3 has a jump near ΔT = 23.2 ° C) to power the fan active cooling radiator! After that, the active cooling fan is switched on and the generation efficiency becomes higher than that during the idling study. This means that the use of active cooling of the radiator makes sense in such devices. The scientific novelty of the work is to confirm the possibility of creating a heat generator using as a source of energy available in everyday life temperature difference, in particular, obtained the characteristics of the modern Peltier element. The practical significance of the work lies in the possibility of using the device at home when using a heated battery to obtain electricity that can be used to connect a flashlight, humidifier, charge the fitness bracelet.

STUDY OF PELTIER ELEMENT POWER CHARACTERISTICS

Цель исследования состоит в определении количества выделяемой и поглощаемой теплоты элементом Пельтье марки ТЭК-12705, который в силу своих конструкционных особенностей имеет особую характеристику по потреблению электрической энергии, зависимости которой и необходимо определить. Материалы и методы исследования. Для достижения цели исследования и ответа на поставленные исследовательские вопросы было проведено экспериментальное исследование. Объектом исследования являлся термоэлектрический преобразователь, для которого были созданы условия, позволяющие наблюдать характеристики элемента Пельтье в замкнутой термодинамической системе. Элемент Пельтье – это термоэлектрический преобразователь, принцип действия которого базируется на эффекте Пельтье, а именно возникновении разности температур при протекании электрического тока. В основу работы элементов Пельтье положен спай двух полупроводниковых материалов с разными уровнями энергии электронов в зоне проводимости. При протекании тока через контакт таких материалов электрону необходимо приобрести энергию, чтобы перейти в более высокоэнергетическую зону проводимости другого полупроводника. При поглощении этой энергии происходит охлаждение места контакта полупроводников. Принимая во внимание компактные габаритные размеры этих элементов (пластинки толщиной от 3 до 7 мм), можно заключить, что данные устройства могут быть использованы в сушильных установках. Результаты исследования и их анализ. Результаты настоящего исследования показали, что при изменении разности температуры элемента Пельтье марки ТЭК-12705 от 16,1 до 50,2 °С потребляемая им мощность изменяется от 36,6 до 30,1 Вт, при этом напряжение питания составляет 11,2 В. Продолжительность работы следует определять экспериментальным путем, так как эффективность работы элемента зависит от эффективности теплоотвода. Заключение. В результате проведённого исследования были установлены зависимости, показывающие, что работа элемента Пельтье по своей характеристике наиболее близка к линейному нагревательному устройству, но только при продолжительной эксплуатации и превышении рабочей температуры выше нормы. Problem and goal. The purpose of this study is to determine the amount of heat released and absorbed by the Peltier element of the TEK-12705 brand, which, due to its design features, has a special characteristic for the consumption of electrical energy, the dependencies of which must be determined. Methodology. To achieve the research goal and answer the research questions, an experimental study was conducted. The object of the study was the thermoelectric converter itself, for which conditions were created that allow us to observe the characteristics of the Peltier element in a closed thermodynamic system. The Peltier element is a thermoelectric converter, the principle of operation of which is based on the Peltier efect, namely, the occurrence of a temperature diference when an electric current fows. The work of the Peltier elements is based on the junction of two semiconductor materials with diferent levels of electron energy in the conduction band. When a current fows through the contact of such materials, the electron needs to acquire energy in order to move to a higher-energy conduction band of another semiconductor. When this energy is absorbed, the contact point of the semiconductors cools. Taking into account the compact overall dimensions of these elements (plates with a thickness of 3 to 7 mm), it can be concluded that these devices can be used in drying plants. Results. The results of this study showed that when the temperature diference of the Peltier element of the TEK-12705 brand changes from 16.1 to 50.2 °C, the power consumed by it changes from 36.6 to 30.1 W, while the supply voltage is 11.2 V. The duration of operation should be determined experimentally, since the efciency of the element depends on the efciency of the heat sink. Conclusion. As a result of the conducted research, the dependences were established, showing that the operation of the Peltier element in its characteristic is closest to a linear heating device, but only with prolonged operation and exceeding the operating temperature above the norm.

Controller design by the motion separation method with applying stability criterions for non-linear objects with transport delays

Controllers and feedback are applied for performing many technical tasks, for example, maintaining the desired temperature stabilization in the thermostat and speed electric motor stabilization. Different methods such as the time-scale separation method, the frequency-response design method, and the Ziegler–Nichols method are applied to design controllers. The Ziegler–Nichols method does not provide the required transient process quality. The Smith predictor is sometimes applied to control objects with a transport delay. However, it may be difficult to apply the Smith predictor when a mathematical model is not fully known. There is a paper where the application of the motion separation method with a delay is considered. However, the calculation method proposed in that work requires solving a system of four nonlinear equations for a second-order object. Therefore, in this paper, we investigate the possibility of a simpler method for calculating the controller, namely, the possibility of using the Mikhailov criterion in the synthesis of a controller by the motion separation method for nonlinear objects with a delay. Also, the application of the Nyquist stability criterion with a simpler than the proposed earlier calculation procedure is considered in the paper. The values of the regulator coefficients obtained using the Nyquist criterion and the Mikhailov criterion are compared. The Mikhailov criterion and the Nyquist criterion are applied to estimate the stability of the fast motions subsystem. The derivation of formulas to calculate the parameters of the controller designed by the motion separation method for first-order non-linear objects with transport delays and second-order non-linear objects with transport delays with the use of the Mikhailov criterion is also considered in the paper. Transient processes are studied by numerical simulation. Transient processes plots are also given. The parameters of the controller that are needed to improve the performance of transient processes in the presence of a delay are found. The Peltier element, an aircraft strength test stand, a thermostat, and equipment for metal rolling are non-linear control objects with a transport delay. The Mikhailov hodographs for objects with a transport delay are presented.

Design of Peltier Element Based on Semiconductors with Hopping Electron Transfer via Defects

The study of thermoelectric properties of crystalline semiconductors with structural defects is of practical interest in the development of radiation-resistant Peltier elements. In this case, the spectrum of energy levels of hydrogen-like impurities and intrinsic point defects in the band gap (energy gap) of crystal plays an important role.The purpose of this work is to analyze the features of the single-electron band model of semiconductors with hopping electron migration both via atoms of hydrogen-like impurities and via their own point triplecharged intrinsic defects in the c- and v-bands, as well as to search for the possibility of their use in the Peltier element in the temperature range, when the transitions of electrons and holes from impurity atoms and/or intrinsic defects to the c- and v-bands can be neglected.For Peltier elements with electron hopping migration we propose: (i) an h-diode containing |d1)and |d2)-regions with hydrogen-like donors of two types in the charge states (0) and (+1) and compensating them hydrogen-like acceptors in the charge state (−1); (ii) a homogeneous semiconductor containing intrinsic t-defects in the charge states (−1, 0, +1), as well as ions of donors and acceptors to control the distribution of t-defects over the charge states. The band diagrams of the proposed Peltier elements in equilibrium and upon excitation of a stationary hopping electric current are analyzed.A model of the h-diode containing hydrogen-like donors of two types |d1) and |d2) with hopping migration of electrons between them for 50 % compensation by acceptors is considered. It is shown that in the case of the reverse (forward) electrical bias of the diode, the cooling (heating) of the region of the electric double layer between |d1)and |d2)-regions is possible.A Peltier element based on a semiconductor with point t-defects is considered. It is assumed that the temperature and the concentration of ions of hydrogen-like acceptors and donors are to assure all t-defects to be in the charge state (0). It is shown that in such an element it is possible to cool down the metal-semiconductor contact under a negative electric potential and to heat up the opposite contact under a positive potential.