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EP-4739959-A1 - SYSTEM AND METHOD FOR GENERATING LIQUID ICE AND METHOD FOR COOLING

EP4739959A1EP 4739959 A1EP4739959 A1EP 4739959A1EP-4739959-A1

Abstract

The invention relates to a liquid ice production system (1) comprising an insulated container (2) which is suitable for the generation of a rough vacuum and which forms a liquid receiving volume (3) in the lower region and a steam receiving volume (4) in the upper region, wherein the container (2) is provided, in the region of its liquid receiving volume (3), with a liquid inlet opening (5) and a liquid removal opening (6), to which a liquid supply line (8) and a liquid discharge line (11) can be connected, a stirrer (13) which extends into the liquid receiving volume (3) and is designed to stir liquid ice present in the liquid receiving volume (3), and a vacuum pump (14) which is connected to the container (2) in the region of the steam receiving volume (4) and which is designed to reduce the internal pressure of the steam receiving volume (4) at least to the triple point pressure of the liquid to be used, wherein said liquid is in particular to water, characterised in that in the upper region of the steam receiving volume (4) a heat exchanger surface (15) of a heat exchanger is arranged, said heat exchanger being part of a refrigeration machine (16). The invention additionally relates to a method for generating liquid ice and to a method for cooling.

Inventors

  • JURETZEK, UWE
  • GRAEBER, CARSTEN

Assignees

  • Siemens Energy Global GmbH & Co. KG

Dates

Publication Date
20260513
Application Date
20240723

Claims (14)

  1. 1. Liquid ice production plant (1) comprising an insulated container (2) suitable for generating a rough vacuum, which forms a liquid receiving volume (3) in the lower region and a steam receiving volume (4) in the upper region, wherein the container (2) is provided in the region of its liquid receiving volume (3) with a liquid inlet opening (5) and a liquid ice removal opening (6), to which a liquid supply line (8) and a liquid ice discharge line (11) can be connected, an agitator (13) extending into the liquid receiving volume (3) which is designed to stir liquid ice present in the liquid receiving volume (3), and a vacuum pump (14) connected to the container (2) in the region of the steam receiving volume (4) which is designed to reduce the internal pressure of the steam receiving volume (4) at least to the triple point pressure of the liquid to be used, which is in particular water, thereby characterized in that a heat exchanger surface (15) of a heat exchanger which is part of a refrigeration machine (16) is arranged in the upper region of the steam receiving volume (4).
  2. 2. Liquid ice production plant (1) according to claim 1, characterized in that the heat exchanger surface (15) arranged in the steam receiving volume (4) and/or inner surfaces of the container (2) have a surface which prevents ice build-up, in particular a surface which is designed to be hydrophobic.
  3. 3. Liquid ice production plant (1) according to claim 1 or 2, characterized in that the container (2) in the liquid receiving volume (3) has a liquid inlet opening (5) and the liquid ice removal opening (6) arranged barrier (22) which is designed such that it prevents a direct flow of fresh water entering through the liquid inlet opening (5) in the direction of the liquid ice removal opening (6), in particular in the form of one or more container walls projecting into the liquid receiving volume (3).
  4. 4. Liquid ice production plant (1) according to one of the preceding claims, characterized in that it has a liquid ice reservoir (12) which is connected to the liquid ice removal opening (6).
  5. 5. Method for producing liquid ice, in particular using a liquid ice production plant (1) according to one of the preceding claims, which has the steps: a) partially filling a container (2) with a liquid, in particular with water, b) lowering the pressure prevailing within the container (2) until the liquid contained in the container (2) begins to boil and partially evaporates, c) condensing the rising vapor using a heat exchanger surface (15) of a heat exchanger positioned in the upper region of the container (2), which forms part of a refrigeration machine (16), d) pumping the resulting liquid ice into a liquid ice storage tank (12) and e) replacing the pumped-out liquid ice with fresh liquid, in particular with fresh water, wherein the mixture of liquid and ice contained in the container (2) is in particular constantly stirred.
  6. 6. Process according to claim 5, characterized in that the liquid used is water, preferably demineralized water.
  7. 7. Process according to claim 5 or 6, characterized in that the pressure in step b) is reduced to the triple point pressure of the liquid, in the case of water to less than 10 mbar, preferably to about 6 mbar.
  8. 8. Method according to one of claims 5 to 7, characterized in that the heat exchanger surface (15) on which the steam rising within the container (2) condenses in step c) has a temperature below the triple point of the liquid, in the case of water to a temperature slightly below 0°C, in particular about -2°C.
  9. 9. Method according to one of claims 5 to 8, characterized in that the ice content within the container (2) is kept at a maximum of 50-60%.
  10. 10. Method according to one of claims 5 to 9, characterized in that, when a layer of ice forms on the heat exchanger surface (15), the heat exchanger is defrosted, in particular by temporarily switching the refrigerant circuit of the refrigeration machine (16).
  11. 11. Method for cooling the air sucked in by a compressor (19) of a gas turbine (20) using liquid ice, characterized in that a liquid ice production plant (1) according to one of claims 1 to 4 is used and/or liquid ice produced by a method according to one of claims 5 to 10 is used.
  12. 12. Method according to claim 11, characterized in that the liquid ice is pumped directly through a heat exchanger (23) arranged in an intake channel of the compressor (19).
  13. 13. Method according to claim 11, characterized in that the liquid ice is pumped through a heat exchanger which recools an intake cooling circuit of an intake channel of the compressor (19) containing a heat exchanger (23).
  14. 14. Method according to one of claims 11 to 13, characterized in that the water is used for further purposes after cooling the sucked-in air, if necessary after intermediate storage.

Description

Description Liquid ice production plant, method for producing liquid ice and method for cooling The present invention relates to a liquid ice production plant comprising an insulated container suitable for generating a rough vacuum, which forms a liquid receiving volume in the lower region and a vapor receiving volume in the upper region, wherein the container is provided in the region of its liquid receiving volume with a liquid inlet opening and a liquid ice removal opening to which a liquid supply line and a liquid ice discharge line can be connected, an agitator extending into the liquid receiving space, which is designed to stir liquid present in the liquid receiving volume, and a vacuum pump connected to the container in the region of the vapor receiving volume, which is designed to reduce the internal pressure of the vapor receiving volume at least to the triple point pressure of the liquid to be used, which is in particular water. Furthermore, the present invention relates to a method for producing liquid ice, in particular using a liquid ice production plant, as well as a method for cooling the air sucked in by a compressor of a gas turbine and using liquid ice. Due to the progress in renewable energies, gas turbine-based power plants are already being used primarily for the provision of residual load and will be used even more in the future. On the one hand, this leads to a reduced number of operating hours with longer downtimes. On the other hand, the highest possible output should be achieved during the comparatively shorter operating times in order to improve economic efficiency. The output of gas turbines is, among other things, heavily dependent on the temperature of the air sucked into the gas turbine compressor. The colder this is, the higher the output of the gas turbine. Depending on the location, the possible output of the gas turbine-based power plant is limited by a high ambient temperature. A targeted reduction in the intake air temperature enables a significant increase in output of several percentage points. Due to reduced operating hours and the longer interim downtimes, the use of a cold storage system can make economic sense, as it can be charged during the comparatively long downtimes with comparatively low output using inexpensive and possibly otherwise surplus renewable energy, which leads to lower CAPEX. If sufficient energy cannot be provided by renewable energies and an electricity price peak occurs, the gas turbine-based power plant can be operated at increased output thanks to intake air cooling using cold from the storage facility. The cold storage facility is crucial for the economic viability of such an approach. Up to now, intake air cooling systems have generally been designed without cold storage. The most common are evaporative coolers, but these only work satisfactorily when the ambient air has a relatively low level of humidity. Another well-known method is the so-called "wet compression" in which the finest water droplets are injected, which also enter the compressor. It also works when the ambient air has a high level of humidity. What the solutions have in common is a significant water requirement, whereby "wet compression" even requires the use of demineralized water. If no water is available for intake air cooling, another option is to use heat exchangers cooled by refrigeration machines and placed in the intake area of the gas turbine. In general, intake air cooling using refrigeration machines is particularly useful in hot and dry locations because falling below the water dew point has a very negative impact on the cost-benefit ratio. All of these solutions date back to a time when gas turbine-based power plants had many operating hours and few downtimes and low-load periods, and volatile renewable energies were available to a much lesser extent and at significantly higher costs. Cold storage was therefore usually not implemented. Instead, the intake air cooling systems were designed to meet the direct cooling requirements. Due to "economies of scale", the relative benefit of intake air cooling is greater for large gas turbines with an output of, for example, 300 MW than for smaller gas turbines, for example with a maximum output of around 30 MW. Due to the change in market conditions due to now competitive but still volatile renewable energies, cold storage is now an option to improve the economic efficiency of intake air cooling systems and ultimately of gas turbine-based power plants. There are currently three main options for storing cold. Firstly, the use of a correspondingly cold stored liquid, such as glycol-water mixtures, in which the sensitive cold is used The second option is to use ice storage, which uses the latent cold during the phase change from ice to water. The third option is to create ice layers by sprinkling water onto appropriately cold heat exchanger surfaces, which are heated periodically. The ice layer is then melted and falls a