UNPRESSURIZED HEAT ACCUMULATOR WITH COMPENSATION LINE

Abstract

A heat accumulator for storing and providing heat energy accruing when power is generated, includes a tank for a fluid, including an expansion line, which exits from the tank and which extends above the tank in order to increase the static pressure in the tank, the expansion line having an open end opposite the tank-side end for establishing a connection between the tank interior and the atmosphere, wherein the expansion line extends into the tank. A method for storing and providing heat energy accruing when power is generated wherein the fluid is used in a district heating grid and is stored in a tank.

Claims

1-10. (canceled)

11. A method for storing and providing heat energy, which occurs during the generation of electricity, by means of a fluid, wherein the fluid is used in a district heating grid and is stored in a tank of the heat accumulator, wherein an operating pressure in a the hottest part of a heat accumulator comes to lie above a saturation pressure of the fluid corresponding to a maximum possible district heat supply temperature, the method comprising: storing the fluid in a tank, and increasing the static pressure in the tank by a compensation line which starts from the tank and extends above the latter, wherein the compensation line extends into the tank, and wherein a connection of the tank interior to the atmosphere is established with an open end, opposite the tank-side end, of the compensation line, and the fluid, which is water, below an upper region of the tank passes into the compensation line.

12. The method as claimed in claim 11, wherein the compensation line is kept filled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention is explained in detail by way of example and with reference to the drawings, in which, schematically and not to scale:

[0025] FIG. 1 shows a heat accumulator.

DETAILED DESCRIPTION OF INVENTION

[0026] The heat accumulator 1 in FIG. 1 comprises a tank 2 with a height of typically between 10 and 50 meters for a fluid, and a compensation line 3 which starts from the tank 2 and extends, for example, approximately 25 meters above the tank 2 in order to increase the static pressure in the latter. That end 5 of the compensation line 3 opposite the tank-side end 4 is open, as a result of which a connection of a sealed tank interior 6 to the atmosphere 7 is established.

[0027] The static pressure in the tank 2 is increased by the thin, water-filled compensation line 3 extending above the tank 2. The height of the compensation line 3 determines the maximum elevated pressure that can be set in the upper region 14 of the tank 2 and hence the maximum charging temperature, for example 135 C. The compensation line 3 is preferably extended downward through the tank 2 and is connected to the lower colder region 8 of the tank 2.

[0028] During operation, the compensation line 3 is permanently fed (for example, overfed) and hence kept filled with water which is cold (for example, at 60 C.) compared to the maximum charging temperature. The excess water flows at the open end 5 out of the compensation line 3 and falls into a collecting container 10, open to the atmosphere and situated underneath, from where it is pumped back again into the tank 2 via a line 11 within which a pump 12 is connected.

[0029] Different charging/discharging mass flows and incidences of thermal expansion in the heat accumulator are compensated by the permanent filling/overfeeding of the compensation line 3.

[0030] So that the transfer of heat in the tank 2 from the hot to the cold medium is as low as possible, that part 9 of the compensation line 3 which extends into the tank 2 is at least partially thermally insulated.

[0031] In the exemplary embodiment, the tank 2 has a connection 13, arranged in the lower region 8, to the district heat return line, and a connection 15, arranged in an upper region 14, to the district heat supply line.

[0032] The heat accumulator 1 can also be charged and discharged via these connections 13, 15.