RU2008581C1 - Thermoelectric refrigerator for automotive vehicles - Google Patents

Abstract

FIELD: refrigerating appliances. SUBSTANCE: thermoelectric refrigerator has from 2 to 10 thermal batteries on "hot" and "cold" joints of which heat tubes with heat carrier are secured. Refrigerator has device for alternately switching on the thermal batteries. When thermal battery is switched on, heat tube of "cold" joints serves as heat seal precluding reverse flow of heat from "hot" joints of thermal battery to refrigerating chamber. EFFECT: enlarged operating capabilities. 1 dwg

Description

 The invention relates to thermoelectric cooling devices used as automobile, household, portable refrigerators.

 Known thermoelectric car refrigerators with natural convective, as well as forced air and water cooling of the heat exchanger of the "hot" junctions of the thermopile, thermoelectric refrigerators using a cold accumulator, having an additional chamber or heat-conducting bridge.

 Refrigerators are known where the cooling of “hot” junctions of a thermopile is carried out by changing the state of aggregation of a coolant substance.

 Closest to the invention is a thermoelectric cooler having a thermopile and a heat pipe mounted on the "hot" junctions of the thermopile, filled with an intermediate heat carrier that changes its state of aggregation during circulation between the condensation and evaporation zones.

 However, in such a device, the operation of the thermal batteries of the refrigerator in continuous mode requires high power consumption. When the refrigerator is turned off, the temperature in the refrigerator immediately begins to increase due to the penetration of the heat flux through the thermal battery. This is due to the fact that there are no thermal gates on the cold junctions of the thermopile. In the car parks, after turning off the engine, the included refrigerator discharges the battery.

 The aim of the invention is to reduce energy consumption, increase cooling capacity, rate of decrease in temperature and increase thermal insulation.

 This goal is achieved by the fact that the car refrigerator contains from 2 to 10 thermal batteries, working alternately or in pairs, located on the side walls of the camera. The use of less than two thermal batteries will not allow achieving the necessary cooling capacity in the refrigerator chamber when the battery is periodically turned on. Using more than ten thermal batteries will increase the cost, power consumption and weight of the device.

 Alternating (if the device has 2 or 3 thermal batteries) and pairwise (4; 6; 8; 10 thermal batteries) turning on the thermal batteries reduces power consumption and allows you to maintain a low temperature in the refrigerator chamber for a long time.

 Heat pipes are fixed on the “cold” and “hot” junctions of each thermopile. The heat pipe from the side of the "hot" junctions is made in the form of a metal tank with ribbing of the outer wall, which forms part of the wall of the outer case of the refrigerator. The heat pipe is filled with an intermediate coolant (for example, water, acetone, pentane), which changes its state of aggregation during circulation between the condensation and evaporation zones. The heat pipe of "cold" junctions is also a metal tank with a coolant that enhances the cooling capacity of thermal batteries and increases the rate of temperature decrease due to a change in the aggregate state of the coolant. In addition, when the thermal batteries are periodically turned off, the heat pipe of the "cold" junctions serves as a thermal shutter, preventing the flow of heat from the "hot" junctions into the working volume of the refrigerator. This is achieved by the fact that the heat transfer of the "cold" junctions of the thermal battery is attached to the upper part of the heat pipe, where the coolant is in a vapor state. The thermal conductivity of steam is an order of magnitude lower than the thermal conductivity of a liquid. When the thermopile is turned off, when the heat flows back from the “hot” junctions to the “cold” junctions, the heat carrier vapors prevent the flow of this heat into the refrigerator chamber.

 Comparative analysis with the prototype shows that the proposed automobile refrigerator is characterized by high cooling capacity with low power consumption due to the alternate operation of thermal batteries and increased thermal insulation provided by thermal gates. Thus, the claimed device meets the criterion of "Novelty."

 Signs that distinguish the proposed technical solution from the prototype are not identified in other technical solutions when studying this and related technical field, therefore, ensure that it meets the criterion of "significant differences".

 The drawing shows a diagram of a car refrigerator.

 It has two cases made of plastic, for example polystyrene: external 1 and internal 2. The space between the buildings is filled with heat-insulating material 3, for example, foam. Thermoelectric batteries 4 are mounted on the side walls of the chambers. Each thermopile has a heat pipe 5 mounted on the “hot” junctions of the thermopile, in the form of a metal reservoir with coolant. The outer fin surface of this tank is installed in the grooves of the outer plastic case of the refrigerator.

 On the "cold" junctions of thermal batteries, a heat pipe 6 with a coolant is also strengthened. The outer wall of this heat pipe is installed in the grooves of the inner case of the refrigerator. The electronic unit for alternating activation of the thermopiles 7 is placed in one of the walls of the refrigerator. The refrigerator is tightly closed with a lid 8.

 The device operates as follows.

 Thermal batteries 4 located in the side walls of the refrigerator operate independently of each other and are connected in pairs. They are electrically connected to the generator or the car’s battery and the electronic unit 7. Turning on the thermal batteries one at a time reduces the power consumption of the device, which is especially important when the refrigerator is running on battery power.

 The heat pipe of the "cold" junctions 6 during the operation of the thermopile enhances its refrigeration resource, making effective thermal contact between the thermopile and the refrigerating chamber. When the thermopile is turned off, the heat pipe of the "cold" junctions serves as a thermal shutter, preventing the heat from flowing from the "hot" junctions of the thermopile to the cooling chamber. This is ensured by the fact that the heat transfer of the thermopile is in contact with that part of the heat pipe where it is filled with steam whose thermal conductivity is lower than the thermal conductivity of the liquid. The penetration of heat into the chamber when the thermopile is turned off occurs only through the walls of the heat pipe and only a small part is transmitted through the volume of the radiator with steam.

 At the heat junctions of the “hot” junctions of the thermopile, a heat pipe 5 is strengthened, which, with its ribbed surface, is in contact with the environment. In this way, heat transfer is provided "at the hot" junctions of thermopiles.

The proposed thermoelectric car refrigerator, in comparison with the prototype, allows due to the alternate operation of thermal batteries and the use of a heat pipe on “cold” junctions of thermal batteries to reduce energy consumption by 20%; increase the cooling capacity of thermal batteries; increase the rate of temperature decrease in the refrigerator chamber; keep the temperature in the refrigerator compartment lower for a longer time. (56) Copyright certificate of the USSR
N 464769, CL F 25 B 21/02.

Claims (1)

 AUTOMOTIVE THERMOELECTRIC REFRIGERATOR containing a thermopile with a heat pipe filled with a heat carrier for cooling hot junctions, characterized in that it contains 2 to 10 thermopiles, on whose cold junctions a heat pipe with a heat carrier is fixed, and is equipped with a device for alternately switching on the heat batteries.

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