Storage system with a cooling circuit

Abstract

The invention relates to a storage system for storing thermal energy, which has a charging circuit that contains a vaporizer, a compressor, a heat exchanger coupled to a heat accumulator, and an air regulator, connected directly or indirectly to one another. The charging circuit also has a cooling circuit. This comprises the compressor, a cooling circuit air regulator, and a mixer with which water can be introduced into the cooling circuit, connected directly or indirectly to one another.

Description

DescriptionTITLEStorage System With a Cooling CircuitTECHNICAL FIELD

[0001] The invention relates to a storage system for storing thermal energy in which thermal energy is stored in a heat accumulator through a charging circuit. Water can be supplied intermittently in order to ensure that the system can be started reliably.BACKGROUND

[0002] Unneeded energy is available at times that has been obtained in particular in a regenerative manner. At other times, there may not be enough of this energy available. Various storage technologies are used to balance out the acquisition of energy and the need thereof.

[0003] One means of doing so is to store excess heat and electricity in the form of thermal energy in heat accumulators. This thermal energy can then be recovered at a later point in time.

[0004] In one embodiment, a charging circuit contains a vaporizer, a compressor, the heat accumulator and an air regulator. In this case, waste heat from other processors and energy obtained regeneratively is supplied to the vaporizer. Advantageously, the compressor is also powered by energy acquired regeneratively.

[0005] If more energy is needed at another time, the energy in the heat accumulator can be recovered by using it to vaporize and superheat water, such that the steam can be used in a steam turbine to drive a generator.

[0006] One problem with this is starting the charging process, in particular when all of the components of the charging circuit have cooled off. Excessive changes in pressure and temperature must be avoided a this point.SUMMARY OF THE INVENTION

[0007] The object of the present invention is to optimize energy storage and recovery.

[0008] This object is achieved with an inventive embodiment in accordance with the teachings of claim 1 . Advantageous embodiments are the subject matter of the dependent claims.

[0009] First, a storage system for storing thermal energy that has a charging circuit is used, which contains a storage vaporizer, a compressor, a charging heat exchanger coupled to a heat accumulator, and an air regulator, connected to one another directly or indirectly.

[0010] In accordance with the invention, the charging circuit is supplemented with a cooling circuit. This comprises the compressor, a cooling circuit air regulator, and a mixer with which water can be added to the cooling circuit, connected directly or indirectly to one another.DESCRIPTION OF THE INVENTION

[0011] This type of storage system is used to store thermal energy. It comprises a charging circuit and a discharge circuit.

[0012] The charging circuit contains a vaporizer, a compressor, a heat exchanger, and an air regulator, connected directly or indirectly to one another. The heat exchanger is coupled to a heat accumulator for storing thermal energy.

[0013] The charging circuit is operated when the storage system is charging. For this, water is first vaporized in the vaporizer, and the steam is subsequently compressed by the first compressor. The steam from the vaporizer is then compressed and thus heated. A portion of the thermal energy contained in the steam is diverted as it passes through the heat exchanger, and transferred to the heat accumulator. The cooled steam is then conducted through the air regulator before returning to the vaporizer.

[0014] A cooling circuit is used with which the system can be started gently, with low temperature and pressure fluctuations in the charging circuit. In doing so, a portion of the main flow in the charging circuit is diverted when starting the storage system, and conveyed through the cooling circuit. It is also possible to initially conduct the entire main flow through the cooling circuit.

[0015] The cooling circuit contains the compressor, a cooling circuit air regulator, and a mixer for this, connected directly or indirectly to one another. The important thing here is that water can be introduced into the cooling circuit with the mixer.

[0016] It is possible to control the heating and pressurization in the charging circuit by the addition of water through the cooling circuit.

[0017] It is particularly advantageous to be able to control the temperature and pressure in the charging circuit. The flow through the cooling circuit can be controlled by a valve.

[0018] The amount of water flowing through the cooling circuit can also be advantageously controlled with a valve in order to control the temperature and pressure in the charging circuit.

[0019] The temperature is preferably measured in the charging circuit for this, in particular between the compressor and the heat accumulator. This is used to control the amount of water that is added, and the steam flowing around the cooling circuit on the basis of the temperature and / or changes in the temperature.

[0020] An acceptable temperature range and / or limit curve is particularly preferably established for the temperature fluctuations, based on the absolute temperature. When starting the charging cycle, the current temperature is determined. At this point, the amount of water can preferably be controlled on the basis of the difference in the current temperature in relation to the acceptable temperature range with respect to the limit curve.

[0021] Instead of a single compression and heat discharge through the heat exchanger, a multistage assembly is particularly advantageous.

[0022] The charging circuit contains the vaporizer, a first compressor, a first heat exchanger, a first connecting line, a second compressor, a second heat exchanger, a second connecting line, a last compressor, a last heat exchanger, and the air regulator for this, connected directly or indirectly to one another. The heat exchanger is coupled to the heat accumulator.

[0023] The assembly can also advantageously be expanded with one or more additional stages. In this case, the charging circuit contains a third compressor, a third heat exchanger, and a third connecting line between the second connecting line and the last compressor, connected directly or indirectly to one another.

[0024] In order to ensure that the storage system is started gently in the charging cycle, the cooling circuit can be placed on one of the compressors according to the invention.

[0025] Preferably there is a cooling circuit on at least two of the compressors when there are numerous stages. This preferably involves a first cooling circuit on the first compressor and a second cooling circuit on the second compressor.

[0026] It is also fundamentally possible to operate the charging circuit and / or discharge circuit with a medium other than water and steam. By way of example, CO2can be used with greater efficiency, although this is more difficult.

[0027] Other media that have a phase shift from liquid to gas within a technologically reasonable range can also be used. Accordingly, the use of media other than water and steam in the primary charging circuit and / or in the secondary charging circuit, and / or in the storage path, is expressly included in the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The Figure shows a schematic illustration of an exemplary storage system that has a charging circuit and a cooling circuit.DESCRIPTION OF THE EMBODIMENTS

[0029] A storage device 01 that has a charging circuit 11 is shown in the Figure. The essential element of the storage device 01 is the heat accumulator 02. Arrows indicate the flow directions in the circuits 11.

[0030] The charging circuit 11 comprises a first compressor 13.1 with which steam in the charging circuit 11 is compressed and thus heated.

[0031] A first heat exchanger 12.1 , which is coupled to the heat accumulator 02, is connected to the first compressor 13.1. It does not matter whether the first heat exchanger 12.1 is located directly on or in the heat accumulator 02. It can also beseparate therefrom and a storage medium can flow from the heat accumulator 02 through the first heat exchanger 12.1 and back to the heat accumulator 02.

[0032] When the charging circuit 11 is in operation, thermal energy with which the heat accumulator 02 is heated is released by the first heat exchanger 12.1 .

[0033] A second compressor 13.2 and a second heat exchanger 12.2 are connected to the first heat exchanger 12.1. These are analogous to the first compressor 13.1 and the first heat exchanger 12.1.

[0034] There is also a third compressor 13.3 and a third heat exchanger 12.3 in this exemplary embodiment.

[0035] Finally, there is a last compressor 13. n, and a last heat exchanger 12.n, with which thermal energy is transferred to the heat accumulator 02.

[0036] This embodiment has a downstream air regulator 15 and a vaporizer 14 in the charging circuit 11. Regenerative thermal energy is advantageously supplied to the vaporizer 14.

[0037] It is possible to more effectively control the starting of the charging cycle 11 with regard to pressure and temperature with the cooling circuit according to the invention.

[0038] There is a first cooling circuit on the first compressor 13.1 and a second cooling circuit on the second compressor 13.2 in this example.

[0039] Each cooling circuit contains a cooling circuit air regulator 16.1 , 16.2 and a mixer 17.1 , 17.2. Water can be conveyed to the mixers 17.1 , 17.2, which can then be sent to the cooling circuits and therefore to the charging circuit 11.

Claims

Claims1. A storage system (01) for storing thermal energy that has a charging circuit (11) containing a vaporizer (14), a compressor (13.1 , 13.2, 13.3, 13. n), a heat exchanger (12.1 , 12.2, 12.3, 12. n), and an air regulator (15), wherein the heat exchanger (12.1 , 12.2, 12.3, 12. n) is coupled to a heat accumulator (02), characterized by a cooling circuit that comprises the compressor (13.1 , 13.2), a cooling circuit air regulator (16.1 , 16.2), and a mixer (17.1 , 17.2), connected directly or indirectly to one another, wherein water can be introduced into the cooling circuit with the mixer (17.1 , 17.2).

2. The storage system (01) according to claim 1 , wherein the flow through the cooling circuit can be controlled with a valve, and / or wherein the amount of water that is introduced can be controlled with a valve.

3. The storage system (01) according to claim 1 or 2, wherein the charging circuit comprises the vaporizer (14), a first compressor (13.1 ), a first heat exchanger (12.1) a first connecting line, a second compressor (13.2), a second heat exchanger (12.2), a second connecting line, a last compressor (13. n), a last heat exchanger (12. n), and the air regulator, connected directly or indirectly to one another, and / or wherein the charging circuit (11) comprises a third compressor (13.3), a third heat exchanger (12.3), and a third heat connecting line between the second connecting line and the last compressor (13.n), connected directly or indirectly to one another.

4. A method for starting the charging process in a storage system (01) according to any of the preceding claims, wherein the temperature in the charging circuit (11) is determined, in particular between the compressor (13.1 , 13.2, 13.3, 13.n) and the heat accumulator (02), and the amount of water that is added is controlled on the basis of the temperature and / or a change in temperature.The method according to claim 4, wherein an acceptable temperature and / or a limit curve for the temperature range is established on the basis of the absolute temperature, and the current temperature is determined, wherein the amount of water is regulated on the basis of the difference between current temperatures and acceptable temperatures with respect to the limit curve.

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