DE3521027A1 - Electrically heated or solar-heated cooker with heat accumulator - Google Patents

Abstract

An accumulator container is filled with a liquid heat transfer medium (thermal oil). Arranged in the centre on the accumulator container is an expansion space, in which cone valves with regulating levers are arranged. Around the expansion space, cooking plates are embedded in the insulation on the accumulator container. From the cooking plates, down pipes lead outside the accumulator container in the insulation to the ground. For the cooking process, the cone valve is opened with the regulating lever. The heat transfer medium flows through the cooking plate and cools down, after which it flows by convection in the down pipe to the bottom of the accumulator container. The circuit for the circulation is thus closed. The accumulator container is equipped with connection pipes for heating by solar collectors and with at least one electric resistance heater for electric heating. The cooker is universal and can also be heated by small wind and water power installations. Its use is therefore possible in many regions.

Description

Electrically or solar-heated stove with heat storage.

The invention relates to an electrically and / or solar heated Cooker with heat storage, the heat storage and carrier of which is a liquid medium and heated both by solar panels and by the electrical heating resistor can be.

The stove itself consists of a storage container that is connected to a liquid heat transfer medium is filled and thermally insulated from the outside. On the storage container an expansion space is arranged in the middle, in which the storage fluid above the cone valve. The cone valve immersed in the liquid becomes with a control lever protruding upwards from the expansion space as far as desired opened or closed, which regulates the flow through the hotplate.

The heat transfer medium cools down in the hotplate and flows by convection in a downpipe attached outside the storage container down to the storage floor. The hotplate is provided with bars on the inside for better heat exchange achieve. Further special features emerge from the other subclaims.

Devices for direct cooking during solar radiation are known. They are parabolic mirrors that concentrate the rays in the focal point, in which the saucepan is. Unfortunately, these devices are used by the general public not accepted in the desert countries. They dazzle, have to follow the sun are and are dependent on the time of usable sunshine.

An improved cooking device with a safety block goes from the patent (DE 3226 782 C2>. It has a simple structure and depends on the location and time of day independent. From a solar collector goes diagonally upwards to the storage block Heat pipe in which an easily evaporating medium circulates.

A second heat pipe is arranged above this, which is the storage block connects to a cooking device.

By lifting the solar panel, the storage block with the Cooking device tilted, causing the heat pipe to incline in the opposite direction and in it the heat circulates from the storage block to the cooking device. At the memory block Several openings are provided that have different angles of rise of the heat pipe enable and thus influence the heat transport accordingly.

This type of scheme is complicated. It does not allow a stepless Temperature control over a wide range.

The level of the cooking device can also be difficult to see on all sides bring it into a horizontal position.

The invention has therefore set itself the task of providing a universal to create electrically and / or solar-heated cooking system, the hotplate through circulation of the heat transfer medium regulated by means of a cone valve in the closed Circuit can be controlled according to the heat demand.

This is achieved by a stove with heat storage, as in the Claims is characterized.

The stove is also the storage tank and is equipped with a heat transfer medium, mainly filled with thermal oil. In the middle is a on the storage container Expansion space arranged in which the cone valves are attached to the control levers are. Several hotplates are embedded in the insulation around the expansion space. From the hotplates lead outside the container wall in the thermal insulation depending on a downpipe to the bottom of the container. Thus the cycle is for a circulation of the Heat transfer medium 'closed. For the connection to solar collectors is on the storage tank a flow pipe which opens above and a return pipe is provided on the bottom.

For electrical heating there is an electrical heating resistor near the floor appropriate.

The heat transfer medium (thermal oil) can up to 220 "C electrically from small Wind or hydropower plants or be heated by solar panels. So a long service life is achieved and the stove can be used in many regions Wei'dj By arranging the cone valve in the heat transfer medium within of the expansion space, sealing and insulation problems are avoided.

The cone valve is opened with the control lever for the cooking process. The heat transfer medium flows through the cone valve and the connection piece to the hotplate. Here he gives off the heat via the bars and hotplate to the saucepan, whereby he cools down and flows in the downpipe to the bottom of the storage tank.

Shortly before the end of the cooking process, the circulation is turned off by closing of the cone valve interrupted.

The following numerical example is intended to demonstrate the advantageous mode of operation of the stove.

A stove with a heat storage of 290 1 thermal oil can be a usable Thermal output of 15 kWh with a temperature difference of 220 - 100 "C = 120 OC to save. This enables 7 families of 5 people each to prepare their meals every day.

The stove is easy to assemble and operate because it works without pressure.

The following is a way of carrying out the invention explained in more detail on the drawing. It shows: Figure 1 stove with memory in section and FIG. 2 shows a plan view with partial section according to FIG. 1.

As shown in Figure 1, the stove and the storage container 1 are one Unit. In the middle, an expansion space 2 is arranged on the storage container 1, in which the cone valves 8 lever with the rule 7 in the liquid heat carrier 6 are immersed. Four hotplates are concentric around the expansion space 2 9 embedded in the insulation 13, on which downpipes 12 to the bottom of the storage container 1 are connected. For electrical heating, at least is near the floor a heating resistor 5 installed. For heating by solar panels are a flow pipe 3, which opens into the heat accumulator at the top, and a return pipe 4 arranged on the ground.

Figure 2 shows that in this embodiment, the stove a has a circular shape. The hotplates 9 are arranged at right angles to one another. A partial section shows that the hot plate 9 has webs 11 inside, whereby the Interstices 10 are formed. On the control lever 7 is on the insulation 13 of the Expansion space 2 attached a scale 14, which allows fine adjustment.

For the cooking process, the cone valve 8 is opened with the control lever 7. The heat transfer medium 6 flows through the cone valve 8, the connecting piece to the hotplate 9 and gives off the heat via the webs 11 and the hotplate 9 to the saucepan. It cools down and flows in the downpipe 12 by convection to the bottom of the Storage container 1. Thus, the circuit of the heat carrier 6 is for the cooking process closed. Shortly before the end of cooking, the cone valve 8 is closed again and so the circulation is interrupted. The hotplates 9 can also have a Insulating cover can be provided.

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Claims (4)

Claims 1. Electrically or solar-heated stove with heat storage, its liquid heat transfer medium through solar collectors or an electrical heating resistor is heated, characterized in that in the expansion space (2) of the storage container (1) a cone valve (8) immersed in the heat transfer medium (6) is arranged through its control lever (7) protruding upwards from the expansion chamber (2) controls the flow rate the heat transfer medium (6) through the hotplate (9) and to the bottom of the storage container (1) leading downpipe (12) can be regulated as required. 2. Electric or solar heated stove according to claim 1, characterized in that that the hotplate (9) has webs (11) on the inside, whereby gaps (10) arise, through which the heat transfer medium (6) flows and gives off the heat quickly. 3. Electric or solar heated stove according to claim 1 and 2, characterized characterized in that from the hotplate (9) a downpipe (12) outside the storage container (1) arranged parallel to the container wall in the insulation (13) to the container bottom is in which the cooled heat transfer medium flows downwards. 4. Electric or solar-heated stove according to one of claims 1 to 3, characterized in that several hotplates (9) are concentric around the expansion space (2) are embedded in the insulation (13).