SK762015U1 - Thermoelectric unit using heat-pipe technology - Google Patents

Abstract

A thermoelectric unit using heat-pipe technology is an electrical device that can generate or remove heat from a heat-insulated space. It uses serial-parallel connection of thermoelectric cells (1) on the principle of Peltier effect, by which a direct current controlled by the control unit (2) flows. The thermocouples (1) are connected to the printed circuit board (3) and are mechanically mounted between the aluminum cooler (4) and the heat-pipe cooler (5) by means of mechanical parts - grips. The aluminum heat sink (4) is designed for indoor use, in the room for the required temperature and the heat-pipe cooler (5) is designed for outdoor use, in the heat-dissipating area, both types of heat sinks are equipped with thermoelectric cells (1). heat transfer paste (6) for the best heat transfer. The warm and cold side between the aluminum cooler (4) and the heat-pipe cooler (5) is separated by the thermal insulation (8), e.g. polyurethane foam PUR. The internal aluminum cooler (4) and heat-pipe cooler (5) are blown by the fans (7) to improve heat transfer to the ambient air. Heat-pipe technology conducts heat more efficiently to distant cooler locations, such as heat conduction in aluminum coolers.

Description

Thermoelectric unit using heat-pipe technology

Technical field

This technical solution is used when it is necessary to maintain the temperature, thermally insulated space from the outside space. The technical solution belongs to the field of refrigeration technology.

Prior art

According to the known state, the use of thermoelectric cells on the principle of the Peltier effect is always solved by two copper or aluminum coolers, between which flat ceramic plates of thermoelectric cells are placed. For better heat conduction, thermally conductive pastes are used, which are applied in a thin layer to the ceramic surfaces of the thermocouples with the contact surface of a pair of heat sinks. The coolers are blown by fans for better heat dissipation into the surrounding space. This method of cooling radiators has drawbacks, especially at higher ambient temperatures, when the desired temperature in the refrigerated space cannot be reached.

The essence of the technical solution

The thermoelectric unit using heat-pipe technology uses excellent heat dissipation properties through heat-pipe tubes. Due to the fact that the thermoelectric cell is relatively thin, the heat that is dissipated on the hot side and the heat that is absorbed on the cold side are also affected by radiation due to the small thickness of the thermoelectric cell. The use of heat-pipes allows heat to be dissipated directly from the source to a distance where there is no longer the effect of thermal radiation, heat-pipes dissipate heat directly from the surface of thermocouples to the remote aluminum fins of the cooler. This creates space for sufficient thermal insulation between the cooled and heated side. The concept of two aluminum heatsinks does not allow this, because the contact area of the hot and cold side is significantly larger. Only about 3 mm of air gap (thermocouple thickness) separates the coolers. The thermoelectric unit using heat-pipe technology works in any position.

The advantage of this solution is lower fan noise compared to the use of two aluminum coolers, due to the larger surface of the heat-pipe coolers, it is not necessary to compensate for heat dissipation by more powerful fans.

The disadvantage is the larger dimensions compared to the use of two aluminum coolers, due to the larger cooling area of the hot side.

The power input of the thermoelectric unit using heat-pipe technology is controlled by the control unit with regard to the control methodology, the basic idea of which is to pre-cool the isolated air-conditioned space at night and close the isolated air-conditioned space in the morning before the outdoor temperature rises. In this context, the term insulation state is introduced, (example: thermoelectric power = 300W, insulation power = 10W) This state makes the thermoelectric unit a thermal insulator with variable thermal resistance. This feature of the thermoelectric unit enables controlled control of heat transfer to the air-conditioned space with regard to the maximum use of favorable thermal conditions in the vicinity of the air-conditioned space.

Overview of pictures for you

Figure 1 - shows the thermoelectric unit using heat-pipe technology in the assembled state, unmarked parts are mechanical mounts

Figure 2 - shows the thermoelectric unit using heat-pipe technology in an exploded state, unmarked parts are mechanical mounts

Examples of embodiments

The use of a heat-pipe cooler to remove heat from the thermocouples 1 is advantageous mainly due to the better efficiency of heat transfer to the ambient air, the heat being conducted by heat-pipe tubes to the aluminum fins in the whole area of the cooler as well. An important aspect is that the heat-pipe cooler is designed by the construction itself so that its parts are physically distant from the surface of the thermocouples 1, which significantly eliminates heat transfer by radiation. The aluminum heatsink 4 and the neat-pipe heatsink are connected by a thermally conductive paste to the thermocouples L. The aluminum heatsink 4 and the heat-pipe heatsink are thermally separated by thermal insulation 8. The fans 7 blow the surface of both the aluminum heatsink 4 and the Tieatpipe heatsink. The electrical connection of the thermocouples 1 and the fans 7 is solved by one printed circuit board 3, to which a direct current from a direct current source is supplied and which is controlled for the thermocouples 1 by pulse width modulation of direct current for power regulation or other regulation. The switching on and off of the fans 7 and the power control is controlled by the control unit 2. The control unit 2 can further evaluate the failure of the fans 7, the failure of the thermocouples 1, or measure the temperatures on the outside or inside.

Example 1

The thermoelectric unit using heat-pipe technology is used to transport medicines, food, biological material and other material, where it is necessary to maintain the required temperature, during transport. The thermoelectric unit is powered by DC voltage and can therefore be connected directly to a socket in the car. The thermoelectric unit is powered from DC voltage and therefore does not require mains power when connected to an electric battery, which allows easy transport.

Example 2

The thermoelectric unit using heat-pipe technology is used for cooling technological systems, especially for cooling lead-acid batteries to maintain longevity. The thermoelectric unit is powered from DC voltage and can therefore be connected directly to the voltage of the cooled battery.

Industrial applicability

The use of the technical solution can be in electrical installations of telecommunications operators, control systems, security systems, wherever lead-acid batteries are used as backup power supplies. According to the EUROBAT Standard, the optimum temperature for the operation of lead-acid batteries is 20 ° C in order to maintain their declared service life.

The use of the technical solution can be in healthcare, food industry, refrigeration technology, where there is a great advantage in the mobility of the technical solution and power supply without the need for mains power.

The use of the technical solution can be in the automotive industry for car refrigerators.

Claims (4)

CLAIMS FOR PROTECTION 1. Thermoelectric unit using heat-pipe technology, characterized in that it consists of at least one thermoelectric cell (1), which is provided with a thermally conductive paste (6) and is connected by its surface to at least one aluminum heat sink (4) and at least one heat-pipe cooler (5) and these are thermally insulated from each other by thermal insulation (8). Thermoelectric unit using heat-pipe technology according to claim 1, characterized in that it comprises a control unit (2) for controlling the condition of the fans (7), controlling the output of the thermoelectric cells (1). Thermoelectric unit using heat-pipe technology according to claim 1, characterized in that the connection of the thermoelectric cells (1) and the connection of the fans (7) are made on one printed circuit board (3). Thermoelectric unit using heat-pipe technology according to claim 1, characterized in that the aluminum cooler (4) and the heat-pipe cooler (5) are provided with fans (7).