Thermal energy storage system combining sensible heat solid material and phase change material

Patent metadata

Field	Value
Publication number	US-9841243-B2
Application number	US-201314655722-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Dec 27, 2012
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

The invention relates to a system for the storage and recovery of thermal energy, using, as its medium, at least one phase change material (solid-liquid) and a sensible heat solid material for storing/recovering the heat obtained from an external source in the form of phase change latent heat and sensible heat. The aforementioned materials are duly housed inside a single tank containing at least two zones which are differentiated by the range of temperatures to which they are subjected, each zone containing a different material. The most common configuration consists of three different zones located inside the tank, namely: a hot zone in the upper part of the tank, enclosing an encapsulated phase change material characterized by a high melting temperature; a cold zone housed in the lower part of the tank, containing a phase change material with a low melting temperature; and a middle zone containing a sensible heat solid material.

First claim

The invention claimed is:

1. A thermal energy storage system combining sensible heat solid material and encapsulated phase change material, comprising:
a storage tank containing heat sensible solid material and capsules of encapsulated phase change material in direct contact with a heat carrier fluid, the tank being configured and arranged to store, during charging of the system, thermal energy obtained from an external heat source over a period of time and then, during a discharging of the system, to recover some of the discharged thermal energy and carrying it the recovered thermal energy towards an external consumption unit, wherein the storage tank has two opposed ends, each of said opposed ends including at least one inlet/outlet, by means of which during said charging of the system the heat carrier fluid enters in a hot zone and leaves the tank through a cold zone;
at least one group of encapsulated phase change materials; located in said hot zone and having a high melting temperature within an admissible range of the fluid temperatures for feeding said external consumption unit and prolong the time of operation of the storage system; and
at least one heat sensible solid material which is located:
a) in a middle zone of the storage tank that separates at least two groups of encapsulated phase change materials, a first one that is the one located in said hot zone and second one located in said cold zone and having a low melting temperature within a permissible working range of fluid temperatures for returning to the external consumption unit during the discharging of the system; or
b) in said cold zone.

2. The thermal energy storage system according to claim 1 , wherein the properties of the heat sensible solid materials and encapsulated phase change materials are configured to capture and store the thermal energy that is produced in an external heat unit in a first charging step, and then recover and deliver said stored thermal energy to a second external consumption unit in the second discharging step.

3. The thermal energy storage system according to claim 1 , comprising a phase change material that is encapsulated into capsules or shells or simply into hollow plates of impervious material resistant to wear and corrosion, preventing the phase change material from getting in direct contact with the heat carrier fluid, which could degrade the phase change material.

4. The thermal energy storage system according to claim 1 , wherein said storage tank is arranged vertically and has a side wall and two lids, an upper one and a lower one, each one being thermally insulated by means of an insulating material.

5. The thermal energy storage system according to claim 1 , wherein at least one group of phase change materials, which are selected from: inorganic salts and/or eutectic mixtures thereof including sodium nitrate, potassium nitrate, manganese chloride; different types of metals or metal alloys including zinc or nickel-zinc; different types of paraffin's; or any other suitable material for the working range of temperatures.

6. The thermal energy storage system according to claim 5 , comprising two groups of different encapsulated phase change material with different properties, all depending on the temperatures or melting points of the working or operating temperature of the thermal energy storage system and of the temperature of the cold zone and the hot zone of the tank.

7. The thermal energy storage according to claim 1 , wherein in said group of capsules of encapsulated phase change material located at the hot zone, the capsules having as a primary characteristic a temperature or melting point much higher than the one of the phase changing material located at the cold zone and being impervious preventing the leakage of the phase changing material.

8. The thermal energy storage system according to claim 1 , wherein the tank is arranged vertically and comprises at least one inlet for the access or exit of the heat carrier fluid from the hot zone of the tank that is located in the top part.

9. The thermal energy storage system according to claim 1 , wherein the tank is arranged vertically, comprising at least one inlet for the access or exit of the heat carrier fluid from the cold zone of the tank, said access or exit being located in the bottom part.

10. The thermal energy storage system according to claim 1 , wherein the tank is arranged horizontally, the hot zone being located in one side of the tank and the cold zone in the opposite side.

Assignees

• Univ Politécnica De Catalunya
• Univ Catalunya Politecnica

Inventors

• Oliva Llena Asensi
• Pérez Segarra Carlos David
• Rigola Serrano Joaquim
• Castro González Jesús
• Oliet Casasayas Carles
• Rodríguez Pérez Ivette
• Lehmkuhl Barba Oriol
• Trias Miquel Xavi
• Capdevila Paramio Roser
• Alba Queipo Ramiro
• Ordoño Martínez Manuel Miguel
• Galione Klot Pedro Andrés

Classifications

• F28D20/026 Primary

  with different heat storage materials not coming into direct contact · CPC title

• F28D2020/006

  Heat storage systems not otherwise provided for · CPC title

• F28D20/0056 Primary

  using solid heat storage material (F28D20/0052 takes precedence) · CPC title

• Y02E60/145

  Cross-Sectional Technologies · mapped topic

• F28D2020/0086

  Partitions · CPC title