CN116793132A - Intelligent waste heat recycling system - Google Patents

Abstract

The invention relates to the field of thermoelectric technology, and in particular to an intelligent waste heat recovery and utilization system, which includes: a temperature control part that can sense temperature changes to be measured in the external environment and control the circuit; and a module that generates cooling when the external environment temperature is higher than the set temperature. , when the external ambient temperature is lower than the set temperature, the module performs the thermoelectric conversion part of waste heat utilization. This system is versatile and flexible and can be equipped on existing servers that require high-precision temperature control to reduce power consumption and improve stability.

Description

An intelligent waste heat recovery and utilization system

Technical field

The invention relates to the field of thermoelectric technology, and in particular to an intelligent waste heat recovery and utilization system.

Background technique

The electronic devices commonly used by people in daily life have brought great convenience to people, so one of the most popular research subjects now is the improvement of the performance of electronic devices. Cooling of electronic equipment is very important, and the loss of electrical energy due to high temperatures is becoming more and more important. With the rapid development of economy and technology, the total energy consumption is increasing. As a secondary energy generated during the production process of primary energy, waste heat is rich in resources and comes in various forms, accounting for a large proportion of total fuel consumption. Recently, it is considered to be a conventional energy source with the same development and utilization value as coal, oil, natural gas and hydraulic power. The heat transfer process of electronic equipment includes three methods: heat conduction, heat convection and heat radiation. Among them, heat conduction from the heating element to the radiator and heat convection from the radiator to the surrounding environment are the main heat transfer methods. Therefore, the heat dissipation design of electronic equipment mainly starts from these two aspects. Common heat dissipation methods can be divided into active heat dissipation, passive heat dissipation and thermoelectric cooling according to the way they take away heat from the radiator. Among them, passive heat dissipation mainly includes common natural convection, indirect contact gas-liquid, solid-liquid phase change cooling, and direct contact immersion liquid cooling and phase change cooling; active heat dissipation mainly includes common forced air cooling, forced Liquid cooling and other methods. Traditional electronic equipment cooling equipment generally uses air cooling or water cooling. The air-cooled fin radiator is divided into two parts. The part in direct contact with the heat source is called the fin radiator. It is responsible for drawing out the heat emitted by the heat source, and the fan It is used for forced convection cooling of the radiator. The cooling effect of the air-cooled fin radiator is closely related to the structure of the radiator used. Another factor that affects the effect of air cooling is wind speed. The greater the wind speed, the smaller the thermal resistance of the radiator. However, the greater the flow resistance, the heat dissipation capacity is limited. It is meaningless to increase the wind speed after it exceeds a certain value and cannot be reduced. The temperature drops below room temperature. The water cooling device usually consists of a radiator, water pipes and a water pump, which can give full play to the advantages of water cooling and take away more heat. At the same time, because the water cooling system does not have a fan, it makes less noise. However, the price of the water-cooling system is relatively expensive. Water in a closed state is prone to scale and deterioration. During use, it is necessary to completely prevent water leakage, water interruption, etc. The system has a complex structure, many parts, and its volume and weight are significantly larger than It uses air cooling to dissipate heat, so there are certain restrictions on its application environment.

Thermoelectric technology is an emerging technology that achieves direct conversion of thermal energy and electrical energy. It uses the Peltier effect and Seebeck effect of semiconductor materials, that is, when current flows through the interface of two different materials, it will absorb or release heat from the outside world. In recent years, with the development of semiconductor material manufacturing technology, thermoelectric cooling methods have developed rapidly. The refrigeration end of thermoelectric cooling can control the heat source temperature below the ambient temperature, which is something that conventional air cooling, natural cooling or even liquid cooling cannot do. Thermoelectric refrigeration uses electric energy to achieve efficient and rapid refrigeration in a small range. This technology has the advantages of being vibration-free, noise-free, safe and reliable, and has a wide range of application scenarios in waste heat power generation, refrigerator refrigeration, etc. The Seebeck effect of thermoelectric technology is an effect in which a current is generated in the loop when a temperature difference is generated at both ends of the thermoelectric piece. Thermoelectric generators convert low-grade heat into electricity. Thermoelectric generators generate electricity based on the temperature difference between the two ends. The greater the temperature difference, the higher the power generation performance. Thermoelectric generators generate electricity that can power electronic devices with power requirements ranging from the microwatt (μW) level to the watt (W) level. The Seebeck effect of thermoelectric technology can effectively utilize a large amount of waste heat and waste heat in life and industry to generate electricity, realize secondary utilization of energy, and thereby improve energy utilization efficiency, such as waste heat recovery in human skin, waste heat recovery in combustion chambers, etc. .

Research at this stage often only focuses on the Peltier effect of thermoelectric technology to cool the heat source. The waste heat of the system is directly dissipated in the form of dissipation or only focuses on the Seebeck effect of thermoelectric technology for waste heat recovery. However, although the plug of thermoelectric technology The Baker effect can reduce the temperature of the heat source, but its total heat dissipation capacity is limited by the heat dissipation capacity of the cold end, and its cooling effect is far less than the Peltier effect of thermoelectricity. Therefore, there is a lack of research on the conversion between the two effects and the utilization of the mutual conversion between the two effects to achieve high-precision temperature control.

Contents of the invention

In order to overcome the above shortcomings, the purpose of the present invention is to provide an intelligent waste heat recovery and utilization system. When the heat source temperature is low, the system is connected to a thermoelectric power generation low-temperature circuit for waste heat recovery. When the temperature is high, the system is connected to a thermoelectric refrigeration high-temperature circuit to realize waste heat recovery. Perform refrigeration. When the temperature of the heat source is low, the low-temperature circuit is connected, and the thermoelectric sheet produces the Seebeck effect. At this time, the thermoelectric surface attached to the waste heat source serves as the hot end of the thermoelectric generator, the air side serves as the cold end, and the fan on the air side creates a forced convection environment. To enhance heat exchange, the waste heat of the system can be recovered to convert thermal energy into electrical energy for the operation of other power-consuming devices. As the temperature of the waste heat source gradually increases and exceeds the temperature set by the temperature control module, the temperature control switch of the low-temperature circuit is turned off, the temperature control switch of the high-temperature circuit is closed, and the thermoelectric sheet generates Peltier under the driving of the DC power supply. Effect, the thermoelectric surface attached to one side of the waste heat source serves as the cold end, and the air side serves as the hot end. In an environment of forced air convection, the cold end is cooled to a much lower temperature than the air side, achieving cooling of the heat source. On the contrary, when the temperature of the heat source gradually decreases, the system switches from a high-temperature circuit to a low-temperature circuit, and the thermoelectric sheet converts from cooling the heat source to using the waste heat of the heat source to generate electricity.

The technical solution of the present invention is implemented as follows: a system that realizes intelligent recovery of waste heat and refrigeration of heat sources, including a thermoelectric module and an intelligent temperature identification control device. The system includes a temperature controller that can sense the temperature changes to be measured in the external environment and control the circuit. Intelligent identification control device; when the external environment temperature is higher than the set temperature, the temperature intelligent identification control device generates cold energy; when the external environment temperature is lower than the set temperature, the temperature intelligent identification control device activates a thermoelectric module that can utilize waste heat for thermoelectric conversion.

The thermoelectric module is composed of a thermoelectric sheet, a flat radiator and a fan. The thermoelectric sheet and the flat radiator are attached and filled with thermal conductive medium. The thermoelectric module is close to the waste heat source, and the space between the thermoelectric module and the waste heat source is also filled. There is a heat-conducting medium, and there is a heat-insulating sealing ring outside the thermoelectric piece.

The cooling end of the thermoelectric plate is close to the waste heat source, and the other end is close to the flat plate radiator. The flat plate radiator uses a fan to perform forced air convection heat dissipation.

The temperature intelligent identification control device includes a first temperature control switch and a second temperature control switch. Both the first temperature control switch and the second temperature control switch are equipped with temperature measurement probes, and the accuracy of the temperature measurement probes is greater than ±2°C. The temperature measuring probe is attached to the surface of the waste heat source. The temperature control switch of the high temperature circuit and the temperature control switch of the low temperature circuit are both equipped with temperature probes, and the temperature probes are attached to the surface of the heat source.

The temperature intelligent identification control device includes a parallel circuit composed of the first temperature control switch and a second temperature control switch. When the first temperature control switch is set to be lower than the set temperature T1, the switch is closed, and the second temperature control switch is set to be closed. When the temperature of the waste heat source T0 is higher than the set temperature T1, the switch is closed. When the waste heat source temperature T0 is higher than the set temperature T1, the high-temperature loop is turned on. The high-temperature loop temperature control switch, that is, the second temperature control switch, is closed. At this time, the thermoelectric The chip will produce the Seebeck effect and use waste heat to generate electricity. When the waste heat source temperature T0 is lower than the set temperature T1, the low-temperature loop is turned on, and the low-temperature loop temperature control switch, that is, the first temperature control switch, is closed. At this time, the thermoelectric chip will Under the action of DC power supply, the Peltier effect is generated for cooling.

The invention has the following advantages:

1. The present invention can control the heat source temperature below the ambient temperature, which cannot be achieved by conventional air cooling, natural cooling or even liquid cooling.

2. The present invention can not only achieve precise temperature control of the heat source, but also recover waste heat to achieve secondary utilization of energy.

3. The entire device of the present invention is not only small in size, light in weight, sustainable, can realize heat energy recovery, but also can improve the service life of electronic equipment.

4. The thermoelectric module is easy to load. It only needs to attach the thermoelectric block to the surface of the heat source. It has a long life, simple structure and easy maintenance. Through temperature detection and control means, high-precision temperature control can be achieved.

5. The thermal inertia of the semiconductor refrigeration chip is very small and the cooling time is very fast.

The present invention fills in the single problem of current research on the Seebeck thermoelectric power generation effect and Peltier effect of thermoelectric sheets. In the case of the same thermoelectric sheet, the Peltier effect of thermoelectric technology can be used to cool the heat source, or the waste heat source can be recovered based on the Seebeck effect of thermoelectric technology. Thermoelectric technology combined with temperature sensor control devices can not only realize heat dissipation and waste heat recovery of heat sources, but also achieve high-precision temperature control.

Description of the drawings

In order to explain the technical solution of the present invention more clearly, the accompanying drawings needed to be used in the description of the present invention will be briefly introduced below.

Figure 1 is a schematic diagram of the system of the present invention.

Figure 2 is a schematic structural diagram of the thermoelectric module of the present invention.

In the picture: 1-waste heat source, 2-thermoelectric module, 3-first temperature control switch, 4-second temperature control switch, 5-power supply, 6-temperature measurement probe, 7-fan, 8-flat plate radiator, 9 - Thermoelectric film.

Detailed ways

The content of the present invention will be further described in detail below with reference to the accompanying drawings.

The drawings illustrate specific embodiments of the invention.

Referring to Figure 1, the intelligent waste heat recovery and utilization system of the present invention includes a thermoelectric module 2, a first temperature control switch 3 and a second temperature control switch 4, and a temperature measurement probe 6 carried by them, and a DC power supply 5. The positive electrode of the DC power supply 5 is connected to the thermoelectric chip 9 and the low temperature loop temperature control switch, which is the first temperature control switch 3. The low temperature loop temperature control switch is connected to the electrical appliance. The other end of the thermoelectric chip 9 is connected to the electrical appliance and the high temperature loop temperature control switch, which is the second temperature control. Switch 4 is connected to the negative pole of the DC power supply. The first temperature control switch 3 and the second temperature control switch 4 are both attached with a temperature measuring probe 6, and the temperature measuring probe 6 is attached to the surface of the waste heat source 1. Considering that if the temperature control switch of the high temperature circuit and the temperature control switch of the low temperature circuit have different setting temperatures, the low temperature circuit and the high temperature circuit will be turned on at the same time or both will be open within a certain period of time, so the settings of the high temperature circuit and the low temperature circuit are The temperature is the same and can meet the different needs of users.

Referring to Figure 2, 7 is a fan, 8 is a flat plate radiator, and 9 is a thermoelectric plate. In order to reduce the contact thermal resistance and convection heat transfer thermal resistance, the thermal conductive medium is filled between the thermoelectric sheet 9 and the flat plate radiator 8, and between the thermoelectric sheet 9 and the waste heat source 1. The thermoelectric sheet 9 is provided with a heat-insulating sealing ring. The cooling end of the thermoelectric plate 9 is close to the heat source. Considering that air cooling is used for cooling, the heat transfer coefficient of natural convection is very low, which is much smaller than the heat transfer coefficient of forced convection at the same temperature, so the fan 7 is used to increase the heat transfer coefficient. At the same time, in order to increase the contact area between the thermoelectric sheet and the air, a plate radiator 8 is attached to the other end of the thermoelectric sheet to enhance heat dissipation.

Claims (7)

1. An intelligent waste heat recycling system is characterized by comprising a temperature intelligent identification control device which can sense the temperature change to be detected in the external environment and control a circuit; when the external environment temperature is higher than the set temperature, the temperature intelligent identification control device generates cold energy, and when the external environment temperature is lower than the set temperature, the temperature intelligent identification control device starts the thermoelectric module (2) capable of utilizing waste heat to perform thermoelectric conversion.

2. The intelligent waste heat recycling system according to claim 1, wherein the thermoelectric module (2) is composed of a thermoelectric sheet (9), a flat plate radiator (8) and a fan (7), a heat conducting medium is filled between the thermoelectric sheet (9) and the flat plate radiator (8), the thermoelectric module (2) is close to the waste heat source (1), and the heat conducting medium is filled between the thermoelectric module (2) and the waste heat source (1).

3. The intelligent waste heat recovery and utilization system according to claim 2, wherein a heat insulation sealing ring is arranged outside the thermoelectric sheet (9).

4. The intelligent waste heat recycling system according to claim 2, wherein the temperature intelligent identification control device comprises a first temperature control switch (3) and a second temperature control switch (4), the first temperature control switch (3) and the second temperature control switch (4) are provided with temperature measuring probes (6), and the temperature measuring probes (6) are attached to the surface of the waste heat source (1).

5. The intelligent waste heat recycling system according to claim 4, wherein the temperature intelligent recognition control device comprises a parallel circuit formed by the first temperature control switch (3) and the second temperature control switch (4), the first temperature control switch (3) is closed when being lower than a set temperature T1, the second temperature control switch (4) is closed when being higher than the set temperature T1, the high temperature loop is connected when the temperature T0 of the waste heat source (1) is higher than the set temperature T1, the second temperature control switch (4) is closed, the thermoelectric sheet (9) generates the Seebeck effect at the moment, the waste heat is utilized to generate electricity, the low temperature loop is connected when the temperature T0 of the waste heat source (1) is lower than the set temperature T1, the first temperature control switch (3) is closed, and the thermoelectric sheet (9) generates the Peltier effect to perform refrigeration under the action of the direct current power supply (5).

6. The intelligent waste heat recovery and utilization system according to claim 5, wherein the refrigerating end of the thermoelectric sheet (9) is close to the waste heat source (1), the other end of the thermoelectric sheet is close to the flat radiator (8), and the flat radiator (8) adopts a fan (7) to perform forced air convection heat dissipation.

7. The intelligent waste heat recovery and utilization system according to claim 4, wherein the accuracy of the temperature probe (6) is greater than ±2 ℃.