Claims:1. A system (10) to measure energy level of a phase change material comprising:
a thermal energy storage device (20) comprising:
a container (30) filled with the phase change material,
at least two metallic plates (40) adhere to at least two opposite lateral sides of the container (30);
a capacitive sensor (50) operatively coupled to the at least two metallic plates (40) of the thermal energy storage device (20), wherein the capacitive sensor (50) is configured to measure capacitance between the at least two metallic plates (40) of the thermal energy storage device (20);
a controller (70) operatively coupled to the capacitive sensor (50), wherein the controller (70) is configured to:
receive one or more dielectric values of the phase change material determined based on measured capacitance when the phase change material shifts from a first state to a second state;
compare each of the one or more dielectric values of the phase change material with a predefined threshold dielectric value of the phase change material; and
determine the energy level of the phase change material based on the one or more compared dielectric value.
2. The system (10) as claimed in claim 1, wherein the thermal energy storage device (20) comprises a cuboidal shape.
3. The system (10) as claimed in claim 1, wherein the at least two opposite lateral sides comprises at least two largest lateral side of the container.
4. The system (10) as claimed in claim 1, wherein the container (30) is encapsulated with a layer of conductive material;
5. The system (10) as claimed in claim 1, further comprising a display unit (80) operatively coupled to the controller (70), wherein the display unit (80) is configured to display a determined energy level of the phase change material in real time.
6. A method (210) to measure energy level of a phase change material comprising:
measuring capacitance between the at least two metallic plates of the thermal energy storage device using a capacitive sensor, wherein the thermal energy storage device comprises a container filled with the phase change material; (220)
receiving, by a controller, one or more dielectric values of the phase change material determined based on measured capacitance when the phase change material shifts from a first state to a second state; (230)
comparing, by the controller, each of the one or more dielectric values of the phase change material with a predefined threshold dielectric value of the phase change material; (240) and
determining, by the controller, the energy level of the phase change material based on the one or more compared dielectric values. (250)
7. The method (210) as claimed in claim 1, further comprising displaying, by a display unit, a determined energy level of the phase change material in real time.

Dated this 08th day of November 2019

Signature

Vidya Bhaskar Singh Nandiyal
Patent Agent (IN/PA-2912)
Agent for the Applicant
, Description:BACKGROUND
[0001] Embodiments of a present disclosure relate to a thermal energy storage device and more particularly to a system and a method to measure energy level of stored phase change material.
[0002] The thermal energy storage device allows excess thermal energy to be stored and used hours, days or months later, at scales ranging from individual process, building, multiuser-building, district, town, or region. When a thermal energy storage device changes state, it is difficult to measure how much of the state has changed. For example, when 0-degree water changes to 0-degree ice, inside a fixed plate or thermal energy storage object, it is difficult to measure quantity of latent heat stored within the fixed plate or the thermal energy storage object. Various techniques have been utilized in past to measure the energy level of phase change material in the thermal energy storage object for various applications.
[0003] One such technique includes volumetric change measurement technique. In such technique, a plate encapsulated with a phase change material such as water is placed perpendicular to the ground. When the water starts freezing it results in formation of ice. Furthermore, the height of the ice formed from the water is calculated to measure the change in energy level of water. However, such technique result in inaccurate measurement as the ice formation may be non-uniform in many cases.
[0004] Other techniques involved measurement of energy spent/absorbed, using infrared imaging. Such technique includes infrared sensors to identify the state of the phase change material from 0-degree water to 0-degree ice. However, such technique includes complicated algorithms for measurement and result in complex calculations due to multiple variables and conditional requirements.
[0005] Furthermore, another technique includes measurement of energy level in phase change material using acoustic wave energy. In this technique, the change in sound is measured from 0-degree water to 0-degree ice. However, such technique result in erroneous measurement of energy level in phase change material as the acoustic waves may reflect same sound in 0-degree water and 0-degree ice.
[0006] Hence, there is a need for an improved system and method to measure energy level of a phase change material in a thermal energy storage device to address the aforementioned issue(s).
BRIEF DESCRIPTION
[0007] In accordance with an embodiment of the present disclosure a system to measure energy level of a phase change is provided. The system includes a thermal energy storage device. The thermal energy storage device includes a container filled with the phase change material. The thermal energy storage device also includes at least two metallic plates adhere to at least two opposite lateral sides of the container. The system also includes a capacitive sensor operatively coupled to the at least two metallic plates of the thermal energy storage device. The capacitive sensor is configured to measure capacitance between the at least two metallic plates of the thermal energy storage device. The system further includes a controller operatively coupled to the capacitive sensor. The controller is configured to receive one or more dielectric values of the phase change material determined based on measured capacitance when the phase change material shifts from a first state to a second state. The controller is also configured to compare each of the one or more dielectric values of the phase change material with a predefined threshold dielectric value of the phase change material. The controller is further configured to determine the energy level of the phase change material based on the one or more compared dielectric value.
[0008] In accordance with another embodiment of the present disclosure, a method to measure energy level of a phase change material is provided. The method includes measuring capacitance between the at least two metallic plates of the thermal energy storage device using a capacitive sensor, wherein the thermal energy storage device comprises a container filled with the phase change material. The method also includes receiving, by a controller, one or more dielectric values of the phase change material determined based on measured capacitance when the phase change material shifts from a first state to a second state. The method further includes comparing, by the controller, each of the one or more dielectric values of the phase change material with a predefined threshold dielectric value of the phase change material. The method further includes determining, by the controller, the energy level of the phase change material based on the one or more compared dielectric value.
[0009] To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the disclosure and are therefore not to be considered limiting in scope. The disclosure will be described and explained with additional specificity and detail with the appended figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:
[0010] FIG. 1 is a block diagram representation of a system to measure energy level of a phase change material in accordance with an embodiment of the present disclosure;
[0011] FIG. 2 is a graphical representation of ideal graph to depict change in dielectric due to change in state in accordance with an embodiment of the present disclosure;
[0012] FIG. 3 is a graphical representation of experimental graph to depict change in dielectric due to change in state in accordance with an embodiment of the present disclosure; and
[0013] FIG. 4 is a flow chart representing the steps involved in a method to measure energy level of a phase change material in accordance with an embodiment of the present disclosure.
[0014] Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.
DETAILED DESCRIPTION
[0015] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.
[0016] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.
[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.
[0018] In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
[0019] Embodiments of the present disclosure relate to a system and a method to measure energy level of a phase change material. The system includes a thermal energy storage device. The thermal energy storage device includes a container filled with the phase change material. The thermal energy storage device also includes at least two metallic plates adhere to at least two opposite lateral sides of the container. The system also includes a capacitive sensor operatively coupled to the at least two metallic plates of the thermal energy storage device. The capacitive sensor is configured to measure capacitance between the at least two metallic plates of the thermal energy storage device. The system further includes a controller operatively coupled to the capacitive sensor. The controller is configured to receive one or more dielectric values of the phase change material determined based on measured capacitance when the phase change material shifts from a first state to a second state. The controller is also configured to compare each of the one or more dielectric values of the phase change material with a predefined threshold dielectric value of the phase change material. The controller is further configured to determine the energy level of the phase change material based on each of the one or more compared dielectric value.
[0020] FIG. 1 is a block diagram representation of a system (10) to measure energy level of a phase change material in accordance with an embodiment of the present disclosure. The system (10) includes a thermal energy storage device (20). The thermal energy storage device (20) includes a container (30) which is filled with the phase change material. As used herein, “the phase change material (PCM)” is a substance with a high latent heat of fusion which, melting and solidifying at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid or liquid to gas and vice versa. In a preferred embodiment, the phase change material may include but not limited to water, sodium sulfate, lauric acid, paraffin n-carbon, glycerine, methyl palmitate or the like.
[0021] In one embodiment, the thermal energy storage device (20) may be of a cuboidal shape. In some embodiment, the container (30) may be encapsulated with a layer of conductive material. In a specific embodiment, the thermal energy storage device (20) may be fabricated using high-density polyethylene (HDPE) material.
[0022] Furthermore, the thermal energy storage device (20) includes at least two metallic plates (40) adhere to at least two opposite lateral sides of the container. In one embodiment, the at least two lateral sides of the container may include at least two largest lateral side of the container (30). The thermal energy storage device (20) encapsulation may be constructed of the conductive material, for which the at least two metallic plates (40) may be mounted such that an insulation is inserted between plates and encapsulation to avoid false readings. In a specific embodiment, the selection of metal used in the at least two metallic plates (40) is subject to the type of phase change material (PCM) used and a predefined temperature at which the phase change material (PCM) changes the state.
[0023] Moreover, the system (10) further includes a capacitive sensor (50) which is operatively coupled to the at least two plates (40) of the thermal energy storage device (20). In one embodiment, the capacitive sensor may be coupled to the at least two plates (40) of the thermal energy storage device (20) via a plurality of cables (60). The capacitive sensor (50) is configured to measure capacitance between the at least two metallic plates (40) of the thermal energy storage device (20).
[0024] In addition, the system (10) includes a controller (70) which is operatively coupled to the capacitive sensor (50). In some embodiments, the controller (70) may be coupled to the capacitive sensor (50) using wired connection. In another embodiment, the controller (70) may be coupled to the capacitive sensor (50) using a wireless connection such as wireless fidelity (Wi-Fi), Bluetooth, RFID or the like. The controller (70) is configured to receive one or more dielectric values of the phase change material determined based on measured capacitance when the phase change material shifts from a first state to a second state. In one embodiment, the phase change material may shift from state I to II or state II to III or vice versa.
[0025] The controller (70) is also configured to compare each of the one or more dielectric values of the phase change material with a predefined threshold dielectric value of the phase change material. The controller (70) is further configured to determine the energy level of the phase change material based on the one or more compared dielectric value.
[0026] In one embodiment, the system (10) may include a display unit (80) which is operatively coupled to the controller (70). The display unit (80) is configured to display a determined energy level of the phase change material in real time. In such embodiment, the energy level of the phase change material may be displayed in terms of changing or discharging percentage. In some embodiments, the display unit (80) may include but not limited to a light emitting diode (LED) screen, a liquid crystal diode (LCD) screen, a monitor of a computing device or the like.
[0027] FIG. 2 is a graphical representation of ideal graph (90) to depict change in dielectric due to change in state in accordance with an embodiment of the present disclosure. The graph (90) is plotted between temperature (on x-axis) (100) in degree Celsius and capacitance (on y-axis) (110) in femtofarad. Readings A (120) through B (130) shows the change in dielectric value as the temperature changes. However, when state changes from State I to State II, the dielectric value is suddenly changed from B to C (140). During the increase in temperature for State II to State III, the dielectric value changes from C (140) to D (150) and so on. One embodiment of the experimental values of the dielectric values during the change in states is shown in FIG. 3.
[0028] FIG. 3 is a graphical representation of experimental graph (160) to depict change in dielectric due to change in state in accordance with an embodiment of the present disclosure. The graph (160) is plotted between temperature (on x-axis) (170) in degree Celsius and capacitance (on y-axis) (180) in femtofarad. The experimental reading proves that the change from data point B (190) to data point C (200) the dielectric value is similar as ideally expected. The same range B (190) to C (200) may be divided into equal parts and assigned values to indicate state of charge or energy level.
[0029] FIG. 4 is a flow chart representing the steps involved in a method (210) to measure energy level of a phase change material in accordance with an embodiment of the present disclosure. The method (210) includes measuring capacitance between the at least two metallic plates of the thermal energy storage device using a capacitive sensor, wherein the thermal energy storage device comprises a container filled with the phase change material in step 220. The method (210) also includes receiving, by a controller, one or more dielectric values of the phase change material determined based on measured capacitance when the phase change material shifts from a first state to a second state in step 230.
[0030] The method (210) further includes comparing, by the controller, each of the one or more dielectric values of the phase change material with a predefined threshold dielectric value of the phase change material in step 240. The method (210) further includes determining, by the controller, the energy level of the phase change material based on the one or more compared dielectric values in step 250. In one embodiment, the method (210) may include displaying, by a display unit, a determined energy level of the phase change material in real time.
[0031] Various embodiments of the system and method to measure energy level of a phase change material described above enables a robust system which can be used with any type of phase change material and provide correct type of sensor based on the change in dielectric value of the phase change material.
[0032] Furthermore, the thermal energy storage device is encapsulated, and the cable is shielded to avoid the false reading and reduce the noise during measurement of energy level. The system provides a sensitive solution which properly calibrated with correct sensor and provide the readings in real time.
[0033] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
[0034] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
[0035] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.