JPS62182594A - Heat transfer body for dynamic latent heat accumulator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention makes particular use of phase change materials in which heating and cooling is achieved in a closed vessel or in direct contact with a heat transfer agent that boils and condenses by circulating it. It is used in the field of thermal storage engineering.

Prior Art A number of management structures and methods are known in the problem area of latent heat storage.

The solutions described in technical books and patent literature are: 1) A certain phase change material with as much phase change heat as possible, 2° heat introduction into the phase change material, phase The present invention relates to various materials and additive elements to balance out the special properties of phase transition materials that negatively affect heat extraction from the transition materials.

Interlayers of this type are for example DE, -OS 293795
9, I) D-AP209902. I)1)-Wl
15.1126 etc.

A feature of these solutions is the use of heat transport agents.

These heat transport agents are brought into direct contact with the phase change material to improve heat transfer capabilities and are moved to specifically increase the convective portion of heat transfer.

These solutions propose low-boiling or high-boiling liquids as heat transport agents. The former is, for example, oil, which maintains a fluid state during the introduction and removal of heat. The latter are, for example, coolants that repeatedly boil and condense during the introduction and removal of heat.

In this case, the premise is that the heat transport agent and the phase change material do not dissolve in each other and are separated.

In this case, it is important to note that all inventions in which hard-to-boil liquids are used require the heat transport agent to be moved by a circulation pump, while in other inventions the movement of the heat transport agent is achieved through a boiling process without a drive. mechanical movement is not necessarily required.

Solutions using circulation pumps are for example DE-092
82640/I, I)l-]-083023/19
/I.

DE-O829+651/I. Solutions using boiling and condensing heat transport agents working without circulation pumps are for example DI)-WP 225857 and EPO 079/
I52.

There is one problem with either solution. That is, in the hard state, the phase change material is not permeable or only slightly permeable to all heat transport agents. As a result of the impermeability of the metal, the introduction of heat into the phase change material is prevented or strongly impeded.

Circulation of non-boiling liquids is thereby not possible or is only possible with strong pump pressures. Circulation of the boiling liquid is possible only in the capillaries and cracks present in the phase change material or in the interspaces of the crystals in the phase change material present as layers of the crystals with special additives. During boiling, the vapor rising into the phase change material and the condensate flowing back are relatively hindered in the gap, thus making it impossible to develop a large heat transfer capacity. To solve this problem, DE-P
For liquids that are difficult to boil, S3010625 proposes a so-called melting conductor that is guided vertically through the phase change material, and the phase change material is melted in the form of a conduit by this melting conductor.

The circulation of the heat transport agent inside the heat accumulator can take place without any hindrance, being guided through the pipes.

This solution is an improvement only for liquids that are difficult to boil.

This solution cannot be applied to liquids that easily boil.

On the one hand, the vapor bubbles necessary for heat conduction rise inside the pipe without coming into contact with the phase transition material until heat dissipation, and on the other hand, the vapor bubbles escape through the pipe with an open top, and are trapped inside the heat storage material. It continues to dissipate heat, then condenses and then evaporates again.

A practical solution for boiling liquids may be possible by increasing the heat transfer area required for the introduction of heat, for example by means of ribs and laminae in the phase changer. However, these methods require high material costs and further impede the boiling and condensation process, so this form has hitherto only been used in static latent heat storages to enhance heat transfer capabilities.

Static latent heat storage does not work without these aspects.

OBJECTS OF THE INVENTION It is an object of the invention to improve the heat transfer capacity associated with a heat transport agent in a dynamic latent heat storage device that boils and condenses during heat introduction, while reducing material costs and increasing reliability of operation. It is about increasing.

DESCRIPTION OF THE INVENTION The basic object of the present invention is to enhance the heat accumulation in the phase change material of a dynamic latent heat storage device by means of structural elements.

Problem solving means This problem is solved by a single tubular cage.

This tubular cage consists of an upper small annular conduit and a lower large annular conduit, and these upper and lower large and small annular conduits are connected by numerous pipes extending from the lower annular conduit to the upper annular conduit on a truncated conical (imaginary) mantle. interconnected.

The convection portion of the heat conductor and the annular cage are connected in series or parallel to each other.

In the case of a parallel connection, a portion of the heating medium coming from the heat source is fed to the conventional part of the heat conductor via a distributor in the lower annular conduit.

Starting from this annular conduit, the heating medium travels high through the pipe.
-1 part flows into the annular conduit. The heating medium is then collected in a partially annular conduit and merges in the collector with the flow of heating medium exiting from the conventional section of the heating medium via a return pipe.

In the case of a series connection, the heating medium is first passed completely through the tubular basket and then guided through the conventional part of the heat conductor, or vice versa. In order to place a thermal conductor according to the invention in a dynamic latent heat storage, the conventional part of the thermal conductor must be in contact with the heat transport agent and the tubular cage with the phase change material.

In that case, what is important is to incline the piping in the (imaginary) side chamber of the cage so that the cage does not come out from the phase change material to -1-.

The slope of the tubular cage and the height restriction ensure that vapor bubbles rising from the conventional portion of the heat conductor can rise only in the obstructed inclined conduit.

In this way, the vapor bubble does not rise vertically and without contact with the phase change material and can exit the phase change material without rising and heat dissipation. Continuing, you can't go out from now on without heat dissipation.

The condensate generated by heat dissipation is constantly brought into contact with the phase change material by the slope of the pipe on the lower surface of the pipe and returned to the heat conductor, in which case the heat in the condensate is supplied to the phase change material to cause phase change. These steps, in which it is advantageous to preheat the material, result in an increased introduction of heat into the phase change material.

The action of the cage is then adjusted by improving the kinetics of heat introduction and not by expanding the heat transfer surface. Only a few tubes are therefore required to be retrofitted, and an increase in material costs is avoided. According to the present invention, the structure of the truncated conical tubular cage is such that 5 to 20% of the heat introduction capacity enters the phase change material from this tubular cage, and the side lines of the truncated cone are 50 to 50% of the horizontal line.
This is done to create an (inner) angle of 85°. In the special case of using as heating medium a coolant which is condensed by heat dissipation in the tubular cage, the upper annular conduit can be omitted and the opening to one side of the pipe is closed.

In this case, the pipes have the same working behavior as heat pipes filled with coolant. In the second aspect of the invention, the pipe arranged on the (imaginary) generatrix of the truncated cone is replaced by a loop pipe. This is made possible according to the invention by arranging the upper annular conduit directly above the lower annular conduit inside the (virtual) truncated cone. The diameters of the two annular conduits differ only slightly.

In a third embodiment of the present invention, a truncated cone-shaped tubular cage is constructed by forming the base surface of a truncated cone (virtual) by a spiral tube. In this case, two pipes are redundant.

Furthermore, the truncated conical tubular cage can be constructed in such a way that it only accommodates partially obstructed tubes in the plane of the truncated cone generatrices.

The figures showing examples will be described in more detail.

FIG. 1 shows a first embodiment of a tubular cage connected to any conventional heat conductor.

Both systems are configured with heat conductors for introducing heat according to the invention.

The use of known forms of dynamic latent heat storage will be described to illustrate the functional aspects of the thermal conductor.

The heat storage device consists of a pressure-resistant and gas-tight covering 3.

A conventional part 4 according to the invention and a tubular cage and heat conductor 5 for heat extraction are incorporated in the sheathing. The tubular cage is composed of a lower tubular conduit 9, a partially tubular conduit IO1 pipe 7, a distributor 14 for distributing the heat source medium, a collector 15 for collecting the heat source medium and a return pipe 6.

The conventional part 4 of the heat conductor and possibly also the lower annular conduit 9 are in the region of the heat introduction 1 filled with heat transport material.

- There is a phase change material 2 (due to an unnatural density difference),
This surrounds the tubular cage. A heat conduction region 13 is connected to the phase change material 2, and this heat conduction portion is filled only with the vapor of the heat transport agent.

The flow path If for the heat source medium and the flow path 12 for the heat consumption medium are likewise shown. In the case of heat introduction, a heat source medium flows through both the conventional part of the heat conductor and the tubular cage, the melting point of the heat source medium being higher than the melting point of the phase change material.

As a result of the flow through both systems, two processes proceed simultaneously.

On the one hand, the phase change material melts along the pipe 7 of the tubular cage to form a conduit 8, and on the other hand, the heat transport material vaporizes in the area for heat introduction 1 on the surface of the conventional part of the heat conductor 4.

The generated vapor bubbles rise within the pipe and are always in contact with the unmelted phase change material due to the slope of the pipe.

Such non-contact bubble evacuation is not possible. The vapor bubbles have a temperature above the melting point, since vaporization takes place above the melting temperature of the phase change material according to the functioning mechanism of the selected regenerator system.

Contact between the vapor bubble and the solid phase transition material 2, whose temperature is only slightly lower than the melting point in the non-molten state, causes condensation of the vapor with simultaneous conduction of the heat of condensation to the phase transition material.

Conduction of the heat of condensation will gradually heat the material to the melting point, or if already at the melting point, cause a phase change material to be in a soluble state.

The condensate formed from the vapor of the heat transport material drips in the line 8 and, due to the inclination of the line, returns to the phase change material 2 on the underside of the line 8.
come into contact with. The returning condensate is vaporized again in the conventional part of the heat conductor, so that the whole process is repeated in successive cycles.

Since the tubular cage does not protrude from the phase change material, this period is within the phase change material 2 where heat conduction is highly efficient.

From experiments carried out using Na, SO4/IOH, and O as phase change materials, it was found that a latent heat regenerator in which the pipe 7 of the tubular cage (or lateral line of a truncated cone) is inclined at 78 degrees with respect to the horizontal line, and the flow flows through the tubular cage. It has been found that when the amount of heat source medium supplied to the heat source medium is 8%, an increase in efficiency of heat introduction into the heat storage device by 20% can be obtained.

The same degree of efficiency increase would cost about eight times as much material using conventional means, ie, by increasing the heat transfer surface of conventional heat transfer.

[Brief explanation of drawings]

The figure is a longitudinal sectional side view of one embodiment. Symbol ■ in the figure: Heat introduction part, 2: Phase change material, 7: Piping,
9.10...Annular conduit.

Claims (1)

[Scope of Claims] 1) A thermal conductor for a dynamic latent heat storage, in which the processing operation is performed by a heat transfer agent that boils and condenses for heat introduction, and the heat transfer agent is in direct contact with a phase change material, comprising: It consists of a conventional part and a non-conventional part with a molten conductor, which parts are arranged in a dynamic detergent heat storage such that the conventional part is in contact with the heat transport agent and the unconventional part is in contact with the phase change material. In the heat conductor, the melting conductor forms a truncated conical annular cage as follows, i.e., a number of pipes (7) are arranged in a truncated conical shape inclined at an angle of 50 to 85 degrees with respect to the horizontal line. The pipe (7) forms the upper surface of the truncated cone, and the upper annular conduit (10) in the phase change material and the lower annular conduit (9) form the base of the truncated cone. A thermal conductor for a dynamic latent heat storage device, characterized in that the thermal conductor is interconnected through. 2) The pipe (7) is a loop pipe, the upper annular conduit (10) in the phase change material (2) being above the lower annular conduit (9) in the area of heat introduction (1). The thermal conductor described in 1). 3) The thermal transition material according to claim 1), wherein the truncated conical annular cage consists of a helical tube completely located within the phase change material (2). 4) The truncated cone-shaped annular cage has a lower annular conduit (9) and the parent surface consists of a number of upper closed tubes.
) The thermal conductor described in ).