Heat pump system using electrochemical compressor

Abstract

The present invention relates to a heat pump system using an electrochemical compressor. The heat pump system using an electrochemical compressor according to the present invention is characterized by comprising: an evaporator that is provided on a circulation path in which water, which is a refrigerant, travels and vaporizes water by taking heat from the surroundings; an electrochemical water compressor provided between a first path on the gas outlet side of the evaporator forming the circulation path and a second path on the liquid inlet side of the evaporator, and having an anode, a cathode, and a proton exchange membrane disposed between the anode and the cathode, so as to discharge water introduced through the first path and hydrogen introduced through a third path distinct from the first path in a compressed state toward the second path; and an expansion valve provided in the second path between the electrochemical water compressor and the evaporator.

Description

Technology Field

[0001] The present invention relates to a heat pump system using an electrochemical compressor, and more specifically, to a heat pump system using an improved electrochemical compressor that enables the implementation of a heat pump cycle by utilizing an electrochemical compressor capable of higher compression efficiency than conventional mechanical compressors. Background Technology

[0002] Recently, as global warming intensifies and extreme weather events such as rising temperatures, heatwaves, and severe cold increase, interest in energy issues and eco-friendliness is growing. The heat pump cycle is being proposed as a solution to these problems. The heat pump cycle has the advantage of being highly efficient compared to conventional heating methods and does not emit carbon dioxide directly. However, it faces the problem that the COP is limited due to the efficiency limitations of the compressor, which accounts for a large portion of the heat pump cycle's power consumption, and that the development of new refrigerants is required due to regulations on existing refrigerants with high GWP (Global Warming Potential).

[0003] Therefore, there is an urgent need for technological development regarding electrochemical water compressors and heat pump systems utilizing the same, which use water as the working fluid—an eco-friendly natural refrigerant emerging as a new refrigerant that possesses excellent thermodynamic properties and low GWP. Prior art literature

[0004] Republic of Korea Registered Patent Publication No. 10-2546563 The problem to be solved

[0005] The present invention has been devised to solve the aforementioned problems, and the objective of the present invention is to provide a heat pump system using an electrochemical compressor that enables the implementation of an efficient heat pump cycle using water, an eco-friendly natural refrigerant, thereby simultaneously improving environmental issues and energy efficiency problems. means of solving the problem

[0006] A heat pump system using an electrochemical compressor according to the present invention for achieving the above objective comprises: an evaporator that is provided on a circulation path in which water, which is a refrigerant, travels and vaporizes water by taking heat from the surroundings; an electrochemical water compressor provided between a first path on the gas outlet side of the evaporator forming the circulation path and a second path on the liquid inlet side of the evaporator, and having an anode, a cathode, and a proton exchange membrane disposed between the anode and the cathode, thereby discharging water introduced through the first path and hydrogen introduced through a third path distinct from the first path in a compressed state toward the second path; and an expansion valve provided in the second path between the electrochemical water compressor and the evaporator.

[0007] The present invention further comprises a gas-liquid separator provided on the second path to separate water and hydrogen discharged through the electrochemical water compressor; and preferably, the third path is configured such that one side is connected to the gas-liquid separator and the other side is connected to the first path, allowing the hydrogen separated through the gas-liquid separator to pass through the third path.

[0008] The present invention preferably includes a regulator provided on the third path to control the discharge pressure of hydrogen.

[0009] The present invention preferably further comprises a heat exchanger provided on the first path between the gas outlet of the evaporator and the electrochemical water compressor to introduce the hydrogen and water into the electrochemical water compressor in a heated state.

[0010] The electrochemical water compressor described above may also comprise: a membrane electrode assembly including an anode, a cathode, and a proton exchange membrane disposed between the anode and the cathode; a pair of separator plates disposed opposite each other with the membrane electrode assembly in between, each having a water passage formed therein through which water can move; and a backflow prevention pattern membrane disposed between one of the separator plates and the membrane electrode assembly, the pattern membrane having a plurality of through slits that allow water passing through the membrane electrode assembly to flow toward one of the separator plates, and backflow prevention parts provided to prevent water passing through each through slit from flowing backward.

[0011] It is preferable that each of the above-mentioned backflow prevention members includes a pair of elastic valve bodies that are spaced apart to form a gap when water passes in the forward direction, thereby enabling water passage, and are restored to their original position to fill the gap after water passes, thereby preventing reverse backflow of water. Effects of the invention

[0012] A heat pump system using an electrochemical compressor according to the present invention having the configuration described above, which exhibits an effect similar to a multi-stage compressor due to the large surface area of ​​the proton exchange membrane and ease of heat exchange, ( By enabling isothermal compression, it overcomes the problem of reduced energy efficiency caused by a significant increase in the temperature of the working fluid during compression due to heat generation in conventional mechanical compressors. Furthermore, as it exhibits behavior similar to the 'Carnot cycle,' which is known as the most ideal cycle with low energy consumption, it enables the implementation of an efficient heat pump cycle using water, an eco-friendly natural refrigerant, thereby effectively solving both environmental and energy efficiency issues simultaneously. Brief explanation of the drawing

[0013] FIG. 1 is a diagram illustrating the configuration and fluid circulation flow of a heat pump system using an electrochemical compressor according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the configuration and operating principle of an electrochemical water compressor employed in one embodiment of the present invention. FIG. 3 is a perspective view of an electrochemical water compressor employed in another embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view showing the configuration illustrated in FIG. 3 separated. Specific details for implementing the invention

[0014] In order to clarify the understanding of the present invention in the following description, descriptions of known technologies regarding the features of the present invention will be omitted. The following embodiments are detailed descriptions to aid in understanding the present invention and are not intended to limit the scope of the rights of the present invention. Accordingly, equivalent inventions that perform the same function as the present invention will also fall within the scope of the rights of the present invention.

[0015] Furthermore, in the following description, identical identification symbols denote identical configurations, and unnecessary redundant descriptions and descriptions of known technologies are omitted. Additionally, descriptions of each embodiment of the present invention below that overlap with the description of the technology forming the background of the invention are also omitted.

[0016] Hereinafter, a heat pump system using an electrochemical compressor according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0017] FIG. 1 is a diagram illustrating the configuration and fluid circulation flow of a heat pump system using an electrochemical compressor according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating the configuration and operating principle of an electrochemical water compressor employed in an embodiment of the present invention.

[0018] As shown in FIGS. 1 and 2, a heat pump system using an electrochemical compressor according to an embodiment of the present invention enables the implementation of a heat pump cycle using an electrochemical compressor that uses water, an eco-friendly refrigerant, without using a conventional mechanical compressor, and comprises an evaporator (51), an electrochemical water compressor (52), and an expansion valve (53).

[0019] The above evaporator (51) is positioned on a circulation path where water, which is a refrigerant, moves, and serves to vaporize water by taking heat from the surroundings, and the above electrochemical water compressor (52) enables refrigerant compression using water, which is an eco-friendly refrigerant, and the above expansion valve (53) lowers the pressure of the refrigerant and expands the capacity while simultaneously enabling control of the flow rate.

[0020] The above electrochemical water compressor (52) is provided between the first path (A1) on the gas outlet side of the evaporator (51) forming the circulation path and the second path (A2) on the liquid inlet side of the evaporator (51), and is equipped with an anode (521), a cathode (522), and a proton exchange membrane (523) disposed between the anode (521) and the cathode (522), so that water introduced through the first path (A1) and hydrogen introduced through the third path (A3), which is distinct from the first path (A1), are compressed and discharged to the second path (A2).

[0021] Here, the hydrogen acts as a carrier gas to increase the compression efficiency of water, allowing water to be compressed smoothly as it passes through the proton exchange membrane (523) together with the hydrogen.

[0022] To explain the principle of water compression in more detail, it is as follows.

[0023] That is, the electrochemical water compressor (52) employed in one embodiment of the present invention comprises a selectively ion-permeable proton exchange membrane (523) (polymer electrolyte membrane), a gas-permeable anode (521) (oxidation electrode) and cathode (522) (reduction electrode), and a bipolar plate that smoothly supplies reaction gas to the anode (521). Although not shown, it is composed of a current collector for applying electricity to each electrode, an insulating plate that prevents leakage current and prevents loss of electrical energy, and an end plate that supports each component at a constant pressure and applies uniform pressure to reduce contact resistance inside the electrochemical water compressor (52).

[0024] Here, the proton exchange membrane (523) is a widely known polymer electrolyte membrane that facilitates proton movement, and is formed with a thickness capable of withstanding high pressure and is coated with a Pt / C catalyst that facilitates electrochemical reactions.

[0025] Hydrogen ( ), water( When ) is supplied and electrical energy is applied using a power supply, hydrogen ( ) is separated and protons( It takes the form of ). Proton( ) is water inside the proton exchange membrane (523) Combines with ) to form hydronium ions ( It moves toward the cathode (522) side through the proton exchange membrane (523) in the form of ). Here, the proton exchange membrane (523) is a membrane that selectively transmits ions when electrical energy is applied, and hydrogen (a general molecule that is not an ion) ) and water( The movement of ) is somewhat restricted. Hydronium ions that have moved to the cathode (522) (Cathode) ) receives electrons from a power source and hydrogen( It is reduced to ).

[0026] The overall chemical formula is as follows.

[0027]

[0028]

[0029] Here, water does not directly participate in the chemical reaction, but hydrogen ( When ) passes over, it also passes over to the cathode (522) by electro-osmotic drag caused by the electric field, and the water ( ) and hydrogen( ) forms high pressure and is discharged in the form of a mixed gas.

[0030] A heat pump system according to one embodiment of the present invention, equipped with an electrochemical water compressor (52) having such an operating principle, has a water (52) that exhibits an effect similar to a multi-stage compression compressor due to the large surface area of ​​the proton exchange membrane (523) and ease of heat exchange. By enabling isothermal compression, it is possible to overcome the problem of reduced energy efficiency caused by a significant increase in the temperature of the working fluid during compression due to heat generation in conventional mechanical compressors. Furthermore, as it exhibits behavior similar to the 'Carnot cycle,' which is known as the most ideal cycle with low energy consumption, it is possible to implement an efficient heat pump cycle using water, an eco-friendly natural refrigerant, thereby allowing for the expectation of simultaneous solutions to environmental and energy efficiency issues.

[0031] Below, we will describe the gas-liquid separator (54), regulator (55), and heat exchanger (56) employed in one embodiment of the present invention.

[0032] The above gas-liquid separator (54) is provided on a second path (A2) corresponding to the path between the electrochemical water compressor and the evaporator (51), and serves to separate water and hydrogen discharged through the electrochemical water compressor (52).

[0033] One side of the third path (A3) is connected to the gas-liquid separator (54) and the other side is connected to the first path (A1), so that hydrogen separated through the gas-liquid separator (54) can be circulated and flowed to the electrochemical water compressor side via the third path (A3).

[0034] The regulator (55) is provided on the third path (A3) to control the discharge pressure of hydrogen, and the heat exchanger (56) is provided on the first path (A1) between the gas outlet of the evaporator (51) and the electrochemical water compressor (52) to supply the hydrogen and water to the electrochemical water compressor (52) in a heated state.

[0035] In particular, a preheating process is required for the isothermal compression of the electrochemical water compressor (52). The heat exchanger (56) enables the preheating of hydrogen and water for efficient isothermal compression by exchanging heat between the high-temperature water introduced through an external line separate from the heat pump circulation cycle according to the present embodiment and the hydrogen separated through the gas separator, as well as exchanging heat between the high-temperature water and the gaseous water produced through the evaporator (51).

[0036] Meanwhile, FIG. 3 is a perspective view relating to an embodiment of an electrochemical water compressor employed in another embodiment of the present invention, and FIG. 4 is an enlarged cross-sectional view showing the configuration shown in FIG. 3 separated.

[0037] As illustrated in FIGS. 3 and 4, the electrochemical water compressor (100) employed in this embodiment comprises a membrane electrode assembly (20) including an anode, a cathode, and a proton exchange membrane disposed between the anode and the cathode, a pair of separator plates (10), and a backflow prevention pattern membrane (30).

[0038] The above pair of separator plates (10) are arranged facing each other with the membrane electrode assembly (20) in between, and each has a passage formed through which water and hydrogen can move.

[0039] The above-mentioned backflow prevention pattern membrane (30) is disposed between one of the separator plates (10) and the membrane electrode assembly (20), and comprises a plurality of through slits (31) and backflow prevention parts (32), and may be composed of conductive rubber, silicone or acrylic-based polymer (PDMS, polydimethylsiloxane) based on functional materials (carbon black, graphene nanoplatelets, ZnO nanorods, AgNWs, graphene oxide, etc.), or a combination thereof.

[0040] Each of the above-mentioned passing slits (31) serves as a passage for hydrogen in the forward direction (see enlarged part a of FIG. 4) to allow hydrogen and water passing through the membrane electrode assembly (20) to flow into the other separator plate (10), and each of the above-mentioned backflow prevention parts (32) serves to prevent backflow in the reverse direction (see enlarged part b of FIG. 4), which is the opposite direction of hydrogen and water passing through each of the above-mentioned passing slits (31).

[0041] An embodiment of the present invention having such a configuration comprises a backflow prevention patterned membrane (30) disposed between a membrane electrode assembly (20) and a separator (10) in which compression of hydrogen and water occurs by an oxidation-reduction reaction, thereby suppressing back-diffusion of the compressed hydrogen and water to the side of the membrane electrode assembly (20) by passing through the membrane electrode assembly (20) and the backflow prevention patterned membrane (30), so that the advantage of improving the compression efficiency of hydrogen and water can be expected.

[0042] The above-mentioned backflow prevention pattern film (30) can be implemented with various structures or materials to prevent back-diffusion of the compressed hydrogen and water, but in this embodiment, it is made by including an elastic conductive polymer material so that the passing slit (31) and the backflow prevention part (32), which are the basic components of the backflow prevention pattern film (30), can be integrally formed by a single material, thereby enabling ease of molding and simplification of the structure, which enables improved mass production of the product and reduction of manufacturing costs.

[0043] Each of the above-mentioned backflow prevention parts (32) employed in this embodiment comprises a pair of valve bodies (32a) (32b) having elasticity that are spaced apart to form a gap when hydrogen passes forward, as well illustrated in enlarged portions (a) and (b) of FIG. 4, to enable hydrogen passage, and are restored to their original positions to fill the gap after hydrogen passes, thereby preventing reverse backflow of hydrogen.

[0044] The present embodiment having such a configuration derives the advantage of being able to improve the compression efficiency of water by using a pair of valve bodies (32a) (32b), which have a structure such as a general check valve that prevents reverse flow of fluid or an artificial valve that prevents reverse flow of blood, as the main components of the backflow prevention pattern membrane (30) of the compressor, and by organically combining this backflow prevention pattern membrane (30) with the membrane electrode assembly (20) and the separator plate (10) of the compressor.

[0045] In the drawing, the unexplained symbol G is a gasket installed for sealing between parts, and 40 is a gas diffuser layer. The gas diffuser layer (40) is made of a porous conductive material such as carbon paper or metal foam, so as not to hinder the movement of gas flowing from the separator (10)(10) toward the membrane electrode assembly (20), and the oxidation reaction caused by the voltage applied to the membrane electrode assembly (20) occurs evenly throughout the entire path of water and hydrogen movement, thereby contributing to the improvement of water compression efficiency.

[0046] Although various embodiments of the present invention have been described above, these embodiments and the drawings attached to this specification merely clearly illustrate a part of the technical concept included in the present invention. It is obvious that variations and specific embodiments that can be easily deduced by a person skilled in the art within the scope of the technical concept included in the specification and drawings of the present invention are all included within the scope of the rights of the present invention. Explanation of the symbols

[0047] 51: Evaporator 52: Electrochemical water compressor 521: Anode 522: Cathode 523: Proton exchange membrane 53: Expansion valve 54: Gas-liquid separator 55: Regulator 56: Heat exchanger A1: First path A2: Route 2 A3: Route 3

Claims

Claim 1 An evaporator provided on a circulation path where water, which is a refrigerant, travels, and which absorbs heat from the surroundings to vaporize the water; and an electrochemical water compressor provided between a first path on the gas outlet side of the evaporator forming the circulation path and a second path on the liquid inlet side of the evaporator, which is provided with an anode, a cathode, and a proton exchange membrane disposed between the anode and the cathode, thereby compressing water introduced through the first path and hydrogen introduced through a third path distinct from the first path and discharging them toward the second path. A heat pump system using an electrochemical compressor, comprising: an expansion valve provided in the second path between the electrochemical water compressor and the evaporator; a gas-liquid separator provided on the second path to separate water and hydrogen discharged through the electrochemical water compressor; wherein the third path is configured such that one side is connected to the gas-liquid separator and the other side is connected to the first path, allowing hydrogen separated through the gas-liquid separator to pass through the third path; and further comprising a heat exchanger provided on the first path between the gas outlet of the evaporator and the electrochemical water compressor to introduce the hydrogen and water into the electrochemical water compressor in a heated state; wherein the third path is configured such that the other side is directly connected to the first path, allowing hydrogen discharged from the gas-liquid separator to move along the first path together with water in a gaseous state after being introduced into the first path, and allowing the hydrogen to move smoothly to the heat exchanger together with water in a gaseous state. Claim 2 delete Claim 3 A heat pump system using an electrochemical compressor, characterized in that, in claim 1, it includes a regulator provided on the third path to control the discharge pressure of hydrogen. Claim 4 delete Claim 5 A heat pump system using an electrochemical compressor according to claim 1, wherein the electrochemical water compressor comprises: a membrane electrode assembly including an anode, a cathode, and a proton exchange membrane disposed between the anode and the cathode; a pair of separator plates disposed opposite each other with the membrane electrode assembly in between, each having a water passage formed therein through which water can move; and a backflow prevention pattern membrane disposed between one of the separator plates and the membrane electrode assembly, the pattern membrane having a plurality of through slits that allow water passing through the membrane electrode assembly to flow toward one of the separator plates, and backflow prevention parts provided to prevent water passing through each through slit from flowing backward. Claim 6 A heat pump system using an electrochemical compressor, characterized in that, in claim 5, each of the above-mentioned backflow prevention members comprises a pair of elastic valve bodies that are spaced apart to form a gap when water passes in the forward direction to allow water to pass, and are restored to their original position to fill the gap after water passes to prevent reverse backflow of water.

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