KR102184192B1 - Heat accumulator for a motor vehicle - Google Patents

Abstract

The present invention relates to a heat storage device 10 for an automobile, wherein the heat storage device 10 includes a phase change material 5 and a heat insulating material as a heat storage medium, and this heat insulation material is at least one phase change material separated from the heat storage medium It has a layer (2).

Description

Heat accumulator for automobile {HEAT ACCUMULATOR FOR A MOTOR VEHICLE}

The present invention relates to a heat accumulator for an automobile.

In automobiles equipped with an internal combustion engine, the accumulated heat is used to heat the engine more quickly during a cold start of the engine, and thereby a regenerator is used to reduce the fuel consumption in the above operating conditions. . For this purpose, the heat recovered from the exhaust gas is stored in the regenerator for up to 16 hours and released to the engine at a specified time. In this case, inevitably, there is a separate challenge to prevent the heat accumulated by suitable insulation during the time mentioned above from escaping to the outside. In addition, the heat insulating material and the overall heat storage should be designed in a manner that does not take up as much space as possible.

As pre-use objects, heat accumulators having an insulating material including aerogel are known. These heat accumulators are designed to be relatively simple, can be manufactured at low cost, and further have high temperature resistance. However, the insulation properties are limited and results in a relatively thick insulation material. This disadvantage is reduced by so-called vacuum panels, in which the vacuum panels can be filled with, for example, airgel, provide an improved thermal insulation effect, and/or require a reduced installation space. However, the temperature resistance is relatively low. Such vacuum panels are described for example in US 6 863 949 A.

In the end, solutions are given that include vacuum insulation between two housing shells, which have essentially the best thermal insulation properties, but these solutions can not only be manufactured at high cost, but also take 12 to 16 hours. It is not suitable for heat accumulating heat.

Against this background, an object of the present invention is to provide an improved heat storage device.

This problem is solved by the object of claim 1.

Thus, automotive heat accumulators, on the one hand, comprise a phase change material (PCM) as a heat storage medium and an insulating material having at least one PCM layer. This, on the one hand, increases the heat storage capacity of the system as a whole. Thus, an additional, outer PCM layer improves the "thermal inertia" of the insulation and absorbs heat that can be radiated to the surroundings through the insulation without, for example, a solution according to the invention. In this case, a temperature distribution is established over the thickness of the insulating material, and this temperature distribution shows a decrease in temperature from about 140°C to 80°C over the innermost insulating layer. The temperature is actually kept constant by the PCM contained in the heat insulating layer, because the PCM as described above basically accumulates the transferred heat. In the outermost area of the insulating layer, the temperature drops from about 80°C to the ambient temperature level. Furthermore, the decrease in temperature toward the outer surface realizes external insulation by a vacuum insulation panel, as a result of which overall thermal resistance is improved, and at the same time, a smaller installation space is required. In particular, it is expected that the heat storage requirement is achieved at the total thickness of the insulation in the range of about 25 mm, while in conventional insulation systems a thickness of about 80 mm is expected to be required, as a result over the entire thickness of the system with insulation in the front. 110 to 120 mm will be saved.

In general, the present invention can be regarded as a heat accumulator comprising a three-layered insulating material, wherein the layers need not necessarily have a PCM layer. Rather, any combination of the above-described and hereinafter described insulation layers is possible within this conceptual scope of the present invention.

Preferred refinements are described in further sections.

Preferably the insulation has in particular one or more aerogel layers on the inner side, i.e. lines for coolant flowing around the PCM to dissipate heat to the PCM and/or on the inner side of the PCM. The temperature of the PCM, which can reach a maximum of 140° C., dropped to about 80° C. by the most internal insulation made of airgel, and as a result, the first critical step reached the predominant ambient temperature level on the outer surface of the regenerator. With regard to the internal insulation made of airgel, this insulation can be replaced by such a vacuum panel if a vacuum panel is selected that can withstand the prevailing temperatures on the inside.

Outside the further PCM layer according to the invention, there is preferably a vacuum insulation panel or vacuum insulation panel, also hereinafter referred to as a vacuum panel, since such panels can withstand temperatures of up to about 80° C. , By the configuration according to the present invention, the above-described temperature level has already been reached on the inner side of the vacuum panel). The outermost vacuum panels provide good insulation in a desirable manner and with less installation space requirements, as a result of which heat can accumulate during the above-mentioned time. The vacuum insulation panel is basically a heat insulation material occluded in a vacuumized coating material.

Preferably, the outermost vacuum panel is filled, particularly with airgel.

The need for particularly small installation space described above can be achieved through particularly preferred embodiments, in which the innermost airgel layer has a thickness of 13 to 17 mm, preferably about 15 mm, and/or The outermost vacuum panel has a thickness of about 4 to 6 mm, preferably about 5 mm, and the total thickness of the insulation material reaches 20 to 30 mm, preferably about 25 mm.

Hereinafter, embodiments shown in the drawings will be described in detail with reference to these drawings.
1 schematically shows the arrangement of a heat accumulator in a thermal management system of an internal combustion engine.
2 schematically shows a cross-sectional view of a heat accumulator according to the present invention.
Figure 3 shows a temperature change according to the thickness of the heat insulating material of the heat storage device according to the present invention.

As shown in FIG. 1, a compressor 16 is installed in front of the internal combustion engine 14 in the flow direction, and the exhaust gas discharged from the internal combustion engine 14 first flows through the exhaust gas turbine 18. After passing, it is passed through a catalytic converter 20. In order to prevent ceramic particles that can be discharged from the catalytic converter 20 from reaching the fresh air side together with the recirculated exhaust gas, a filter 22 is installed behind the catalytic converter 20 in the flow direction. Is active in full operation.

Through the internal combustion engine 14, an oil circulation system 24 is guided on the one hand, and a coolant circulation system 26 on the other hand. The oil circulation system 24 is guided through an oil-coolant heat exchanger 28. On the other hand, the coolant circulation system 26 has a valve 26, which will guide the coolant flow through the radiator 28 to dissipate heat in an operating state in which the internal combustion engine 14 is to be cooled. I can. The additional valve 30 allows the coolant flow to pass through the regenerator 10 or through the exhaust gas-coolant heat exchanger 32.

The heating of the engine in the engine low temperature condition is supported by the coolant passing next to the radiator 28 by the appropriate position of the valve 26 and passing the heat accumulator 10 by the appropriate position of the valve 30, thus This allows the engine to heat up quickly.

In the first step, the valve 30 is switched so that the coolant no longer passes through the regenerator 10, typically reaching a state where it has released the heat that has already been regenerated at this point. On the other hand, the coolant is guided through the heat exchanger 32, whereby heat can be absorbed from the exhaust gas in the heat exchanger. In addition, the oil guided through the heat exchanger 28 absorbs heat. The corresponding position of the valve 34 in this case allows the entire exhaust gas heat to be used not only for heating the coolant, but also for oil heating.

When the engine is sufficiently heated, cooling of the oil is required, which takes place in the heat exchanger 28, which now dissipates the heat taken from the oil to the heat accumulator 10. The heat of the coolant can be dissipated through the radiator 28 by the corresponding position of the corresponding valve 26. Supplementally, the exhaust gas heat management module described above is denoted by reference numeral 36.

As can be seen from Figure 2, the heat accumulator 10 according to the present invention includes a PCM 5 as a heat storage medium in which the coolant flows around it, wherein the coolant is in connection with this through the inlet 6 It reaches the inside of the provided lines, and after heat is dissipated to the PCM (5), it leaves the lines through the outlet (7). Airgel is provided on the inner heat insulating layer 1 outside the vessel 4 surrounding the lines and/or the PCM, and the PCM layer 2 according to the present invention is provided outside the inner heat insulating layer. The outer surface is formed by a vacuum insulating panel 3.

In other words, the airgel layer 1 is in contact with the vessel 4, and/or the lines, and/or the PCM 5. Between the airgel layer 1 and the PCM layer 2 a thin layer of material may be provided for delimiting, and in the outward direction the PCM layer 2 is a vacuum insulating panel 3, in particular such a vacuum insulating panel Contact with the inner cladding of

As shown in FIG. 3, in the heat accumulator according to the present invention, a temperature change is given according to the temperature of the heat insulating material, and in this case, the temperature drops from about 140° to about 80° over the inner heat insulating layer 1. The heat insulating layer may have a thickness of, for example, about 1.5 cm. For example, the temperature is actually kept constant over the PCM (2) contained in the insulating layer, which may have a thickness of 0.5 cm, because the PCM basically stores the transferred heat. In the region of the outermost insulating layer 3, the temperature drops from about 80° to the ambient temperature level.

Claims (7)

A phase change material (PCM) 5 as a heat storage medium, a coolant line flowing around the phase change material 5, and an insulating material surrounding the coolant line, the The insulating material has at least one phase change material layer 2 separated from the phase change material 5,
The phase change material layer (2) is characterized in that the heat storage capacity is increased while preventing the heat from escaping to the outside by accumulating heat of the coolant line separately from the phase change material (5). (heat accumulator)(10). 2. The automotive heat accumulator according to claim 1, characterized in that the heat insulating material has at least one aerogel layer (1). 2. An automotive heat accumulator according to claim 1, characterized in that the insulation has at least one vacuum insulation panel (3). 4. The vehicle heat accumulator according to claim 3, wherein the vacuum insulation panel is filled. The vehicle heat accumulator according to claim 2, wherein the airgel layer has a thickness of 13 to 17 mm. 4. The vehicle heat accumulator according to claim 3, wherein the vacuum insulation panel has a thickness of 4 to 6 mm. 7. The automobile heat accumulator according to any one of claims 1 to 6, wherein the heat insulating material has a total thickness of 20 to 30 mm.

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