KR20220136520A - High efficiency liquefied hydrogen vaporization system using a heat pump - Google Patents

Abstract

The present invention relates to a high-efficiency liquefied hydrogen vaporization system using a heat pump, which vaporizes liquefied hydrogen to be supplied to a fuel cell by using the refrigerant of the heat pump that exchanges heat with oxygen exhausted from the fuel cell. The high-efficiency liquefied hydrogen vaporization system comprises: a liquefied hydrogen tank for storing and discharging liquefied hydrogen; a fuel cell for exhausting oxygen having a medium temperature, which is waste heat generated while vaporized hydrogen generated through vaporization of the liquefied hydrogen reacts with oxygen, or oxygen having a relatively higher temperature than the medium temperature, through a waste heat exhaust passage; an electric damper having a waste heat inlet port connected to the waste heat exhaust passage, an outdoor air inlet port connected to an outdoor air inlet passage, and a fluid exhaust port connected to a fluid exhaust passage, and having a damper wing for communicating the waste heat inlet port and/or the outdoor air inlet port and the fluid exhaust port; and the heat pump for vaporizing the liquefied hydrogen with high-temperature, high-pressure refrigerant generated on the basis of heat exchange with a fluid, which is at least one of outside air exhausted along the fluid exhaust passage connected to the fluid exhaust port according to the operating state of the fuel cell, air mixed with the outside air and the oxygen having the medium temperature, and the oxygen having the higher temperature. Therefore, the high-efficiency liquefied hydrogen vaporization system can implement the refrigerant cycle of the heat pump by using waste the heat and/or outside air exhausted from the fuel cell, thereby efficiently vaporizing the liquefied hydrogen.

Description

High efficiency liquefied hydrogen vaporization system using a heat pump

The present invention relates to a high-efficiency liquid hydrogen vaporization system using a heat pump, and more particularly, using a heat pump that vaporizes liquid hydrogen to be supplied to a fuel cell using the refrigerant of the heat pump heat-exchanged with oxygen exhausted from a fuel cell. It relates to a high-efficiency liquid hydrogen vaporization system.

Hydrogen does not emit any pollutants during combustion, and when combined with oxygen, water (H ₂ O) is finally created as an eco-friendly energy.

When hydrogen energy is used as liquid hydrogen, it has the highest energy density to weight on earth, and storage efficiency can be secured with a volume of less than 1/770 compared to vaporized hydrogen.

Meanwhile, a fuel cell is a power generation system that converts chemical energy into electrical energy by an electrochemical reaction between hydrogen and oxygen. Here, as the hydrogen fuel, pure hydrogen may be directly supplied, or hydrogen contained in hydrocarbon-based materials such as methanol, ethanol, and natural gas may be reformed and supplied. Oxygen may supply pure oxygen directly, and may supply oxygen contained in ordinary air using an air pump or the like.

In order for the fuel cell as described above to have a basic system configuration, a fuel container and a reformer that reforms the fuel stored in the fuel container to generate hydrogen gas (hereinafter referred to as 'vaporized gas') and supplies the vaporized hydrogen to the stack ( It requires a reformer and a fuel cell body called a stack that produces electricity.

A reformer, one of the system components of a fuel cell, is a device that converts hydrogen-containing fuel and water into hydrogen vapor required for electricity generation of the stack through a reforming reaction. There was a problem with the cost.

Therefore, while using liquefied hydrogen with a higher energy density than hydrogen vaporized hydrogen, the system configuration of the fuel cell system can produce electricity by supplying hydrogen vaporized to the fuel cell body while excluding the reformer, which is complicated in design and incurs additional costs. necessity was demanded.

Republic of Korea Patent Publication No. 10-1813231 Republic of Korea Patent Publication No. 10-1984122

The present invention was devised to solve the above problems, and after vaporizing liquefied hydrogen having a higher energy density than vaporized hydrogen into vaporized hydrogen through heat exchange by a heat pump, the reformer is supplied to a fuel cell not configured to produce electricity An object of the present invention is to provide a high-efficiency liquid hydrogen vaporization system using a heat pump to make this happen.

In addition, the present invention provides a high-efficiency liquid hydrogen vaporization system using a heat pump that performs a refrigerant cycle of the heat pump for vaporizing liquid hydrogen through waste heat exhausted during the electricity production process of the fuel cell and/or external air input from the outside. It is intended to provide

However, the technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly to those of ordinary skill in the art to which the present invention belongs from the description below. can be understood

In the high-efficiency liquid hydrogen vaporization system using a heat pump for achieving the above object, the liquid hydrogen tank for storing and discharging liquid hydrogen; a fuel cell for discharging medium temperature oxygen, which is waste heat generated during reaction of hydrogen vaporized through vaporization of the liquid hydrogen with oxygen, or oxygen having a relatively high temperature than the medium temperature, to a waste heat exhaust passage; A waste heat inlet connected to the waste heat exhaust passage, an outdoor air inlet connected to the outdoor air input passage, and a fluid exhaust port connected to the fluid exhaust passage are formed, and a damper blade for communicating the waste heat inlet and/or the outdoor air inlet and the fluid exhaust port An electric damper having a; and the external air exhausted along the fluid exhaust passage connected to the fluid exhaust port according to the operating state of the fuel cell, the air in which the outdoor air and the medium temperature oxygen are mixed, and the high temperature oxygen based on heat exchange with a fluid. It may include; a heat pump for vaporizing the liquid hydrogen through the generated high-temperature and high-pressure refrigerant.

In addition, the electric damper closes the waste heat inlet through the damper blade before the fuel cell is operated, and communicates the outdoor air inlet and the fluid outlet to allow the outside air to communicate with the fluid outlet through the fluid exhaust passage can be exhausted to

And the electric damper, when the fuel cell is in an initial operation state to exhaust oxygen at the medium temperature, communicates the waste heat inlet, the outdoor air inlet, and the fluid exhaust port through the damper blade so that the outdoor air and the medium temperature oxygen are in communication. The mixed air may be exhausted to the fluid exhaust passage through the fluid exhaust port.

In addition, the medium temperature oxygen may be waste heat exhausted in the initial operating state before the fuel cell generates heat to a preset operating temperature for reacting the hydrogen vaporized with oxygen.

And the electric damper, when the fuel cell is in a rated operation state for exhausting the high-temperature oxygen, closes the outside air inlet through the damper blade, but communicates the waste heat inlet and the fluid exhaust port to release the high-temperature oxygen It may be exhausted to the fluid exhaust passage through the fluid exhaust port.

In addition, the high-temperature oxygen may be waste heat exhausted in the rated operating state in which the fuel cell generates heat at a preset operating temperature for reacting the hydrogen vaporized with oxygen.

The heat pump may include: an evaporator configured to generate a medium temperature and low pressure refrigerant through evaporation of the low temperature and low pressure refrigerant while cooling the fluid through heat exchange between the fluid and the low temperature and low pressure refrigerant discharged along the fluid exhaust passage; a liquid separator for separating the medium temperature and low pressure refrigerant generated from the evaporator into refrigerant vapor and refrigerant liquid; a compressor for compressing the refrigerant vapor or refrigerant liquid separated through the liquid separator to generate the high-temperature and high-pressure refrigerant; a condenser that vaporizes the liquid hydrogen through heat exchange between the high-temperature and high-pressure refrigerant generated through the compressor and the liquid hydrogen, and generates a medium-temperature and high-pressure refrigerant through condensation of the high-temperature and high-pressure refrigerant; and a first expansion valve configured to expand the medium-temperature and high-pressure refrigerant generated through the condenser to generate the low-temperature and low-pressure refrigerant.

In addition, the heat pump may be provided with a refrigerant moving passage through which the refrigerant moves by connecting the evaporator, the liquid separator, the compressor, the condenser, and the first expansion valve.

The heat pump may include a second expansion valve that communicates with a part of the refrigerant passage connecting the condenser and the first expansion valve and is installed in the refrigerant input passage connected to the compressor.

In addition, in the second expansion valve, in order to prevent overheating of the compressor and increase vaporization efficiency, the low-temperature and low-pressure refrigerant generated by expanding a part of the medium-temperature and high-pressure refrigerant that moves along a part of the refrigerant moving passage is injected into the refrigerant. It may be introduced into the compressor through the passage.

The present invention has an effect of efficiently vaporizing liquid hydrogen by implementing a refrigerant cycle of a heat pump using waste heat and/or outside air exhausted from a fuel cell.

In addition, the present invention has the effect of efficiently operating the refrigerant cycle of the heat pump by selecting the fluid to be exchanged with the evaporator according to the operating state of the fuel cell.

However, the effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be able

1 is a schematic diagram of a high-efficiency liquid hydrogen vaporization system using a heat pump according to an embodiment of the present invention.
2 is a diagram illustrating a state of use of an electric damper according to an embodiment of the present invention.
3 is a block diagram showing a configuration additionally provided in the high-efficiency liquid hydrogen vaporization system using a heat pump according to an embodiment of the present invention.
4 is a schematic diagram of a high-efficiency liquid hydrogen vaporization system using a heat pump according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiment described in the text. That is, since the embodiment is capable of various changes and may have various forms, it should be understood that the scope of the present invention includes equivalents capable of realizing the technical idea. In addition, since the object or effect presented in the present invention does not mean that a specific embodiment should include all of them or only such effects, it should not be understood that the scope of the present invention is limited thereby.

The meaning of the terms described in the present invention should be understood as follows.

Terms such as “first” and “second” are for distinguishing one component from another, and the scope of rights should not be limited by these terms. For example, a first component may be termed a second component, and similarly, a second component may also be termed a first component. When a component is referred to as being “connected to” another component, it may be directly connected to the other component, but it should be understood that other components may exist in between. On the other hand, when it is mentioned that a certain element is "directly connected" to another element, it should be understood that the other element does not exist in the middle. On the other hand, other expressions describing the relationship between elements, that is, "between" and "between" or "neighboring to" and "directly adjacent to", etc., should be interpreted similarly.

The singular expression is to be understood as including the plural expression unless the context clearly dictates otherwise, and terms such as "comprises" or "have" refer to the specified feature, number, step, action, component, part or these It is intended to indicate that a combination exists, and it should be understood that it does not preclude the possibility of the existence or addition of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Terms defined in a commonly used dictionary should be interpreted as having the meaning consistent with the context of the related art, and cannot be interpreted as having an ideal or excessively formal meaning unless explicitly defined in the present invention.

Hereinafter, with reference to the accompanying FIGS. 1 to 3, a high-efficiency liquid hydrogen vaporization system using a heat pump of an embodiment will be described in detail.

Referring to FIG. 1 , a high-efficiency liquid hydrogen vaporization system using a heat pump of an embodiment includes a liquid hydrogen tank 10 , a fuel cell 20 , a pressure control valve 30 , an electric damper 40 , and a heat pump 50 . and a fuel recoverer 60 are provided.

The liquid hydrogen tank 10 stores liquid hydrogen to be vaporized into vaporized hydrogen used as a fuel of the fuel cell 20 . At this time, it is preferable that the internal temperature of the liquid hydrogen tank 10 is maintained at -253 ℃ below -253 ℃ so that hydrogen is in a liquefied state to store the liquid hydrogen in a cryogenic state, and the liquid hydrogen has a high energy density compared to vaporized hydrogen. have.

In addition, the liquid hydrogen tank 10 is connected to the liquid hydrogen discharge path 100 in order to discharge the liquid hydrogen as well as the storage of liquid hydrogen so that the liquid hydrogen is discharged along the liquid hydrogen discharge path 100 .

The fuel cell 20 is a device that converts chemical energy generated by an electrochemical reaction of vaporized hydrogen and oxygen generated by vaporization of liquid hydrogen discharged along the liquid hydrogen discharge path 100 into electric energy to generate electricity, and the present invention The fuel cell 20 may be a hydrogen fuel cell applied to a railway vehicle (train, train, subway, etc.).

The fuel cell 20 includes an alkali fuel cell (AFC), a molten carbonate fuel cell (MCFC), a phosphoric acid fuel cell (PAFC), a solid oxide fuel cell (SOFC), and a polymer electrolyte fuel cell (PEMFC, PEFC). ) and a direct methanol fuel cell (DMFC).

An alkali fuel cell uses an alkali such as potassium hydroxide as an electrolyte, hydrogen as a fuel, and oxygen as an oxidizing agent. In addition, the operating temperature for the reaction of hydrogen and oxygen is 60 ~ 120 ℃ (hereinafter, 120 ℃), the catalyst of the anode (anode, anode) uses platinum-lead on a nickel mesh coated with silver, and the cathode (Anode, Cathode) uses gold-platinum on top of gold-plated nickel mesh.

In a molten carbonate fuel cell, the electrolyte is a mixture of lithium carbide and potassium carbide (Li-K) having a low melting point, and the electrode is made of porous nickel. In addition, the operating temperature is 600 ~ 700 ℃, allowing the reforming of the hydrocarbon gas inside the battery by the heat of the battery stack.

In the phosphoric acid fuel cell, the electrode contains platinum or a platinum mixture as a catalyst on the surface area of the carbon support, and the allowable operating temperature for the reaction of hydrogen and oxygen and the stability of the phosphoric acid electrolyte is 200 to 250 °C.

The minimum unit of a solid oxide fuel cell is a single cell, and the single cell is composed of oxide ceramics of anode and cathode electrolytes. In addition, city gas (CH ₄ ), which is a fuel, reacts with water vapor on the anode to be reformed into hydrogen (H ₂ ) and carbon monoxide (CO), and the operating temperature is 700 ~ 1000 ℃. And it is possible to perform steam reforming in the battery by the catalytic action of Ni, a component of the anode, and oxygen in the air introduced into the cathode is dissociated at the interface with the electrolyte to become oxygen ions (O ² -), It diffuses and moves to the anode. Furthermore, oxygen ions generate water or carbon dioxide through an electrochemical reaction with hydrogen or carbon monoxide generated by the reforming reaction at the electrolyte/anode interface, and electricity is generated by the emitted electrons.

Polyelectrolyte fuel cells are solid polymer polymers (membrane) rather than liquid electrolytes, and are fuel cells using a membrane similar to alkali-type and phosphoric acid-type fuel cells, and use platinum as a catalyst. In addition, compared to phosphoric acid fuel cells, they are operated at a low temperature of 25 to 100 °C, so the output density is large and miniaturization is possible.

The direct methanol fuel cell is a system that generates electricity through direct and electrochemical reaction of methanol. The electrolyte is phosphoric acid supported on an ion exchange membrane, and the operating temperature is relatively low at 25 to 100 °C. Compared with the polyelectrolyte fuel cell, the reformer can be omitted, and the system can be simplified and load responsiveness can be improved.

As such, the fuel cells that can be implemented as the fuel cell 20 must be provided with a reformer that generates hydrogen (hydrogen vaporized) from fossil fuels for the production of electric energy, but in the high-efficiency liquid hydrogen vaporization system using the heat pump of an embodiment, As hydrogen vaporized through the heat pump 50 is generated, the reformer may be omitted from the configuration.

Accordingly, the fuel cell 20 of the present invention is preferably a fuel cell body, which is a stack for generating electricity in the system configuration of the fuel cell.

In addition, the fuel cell 20 is connected to the waste heat exhaust passage 200 to discharge waste heat generated during the reaction of hydrogen vaporized with oxygen as well as for the production of electrical energy, and a fuel recovery passage for recovery of used fuel ( 600) is connected.

In this case, the waste heat generated from the fuel cell 20 may be medium temperature oxygen or oxygen at a relatively high temperature than the medium temperature oxygen.

As a specific example, the medium-temperature oxygen may be waste heat that is exhausted from the fuel cell 20 in an initial operating state before it is heated to a preset operating temperature for reacting hydrogen vaporized with oxygen, and the high-temperature oxygen is the fuel. The battery 20 may be waste heat exhausted during rated operation in which heat is generated at a preset operating temperature for reacting hydrogen vaporized with oxygen.

Accordingly, in a specific example, when the fuel cell 20 is an alkaline fuel cell, the fuel cell 20 exhausts oxygen at a medium temperature from when it generates heat until it heats up to a preset operating temperature of 120° C. When it starts to heat up with temperature, high-temperature oxygen is exhausted.

As another specific example, medium temperature oxygen may be waste heat that is exhausted from when the fuel cell 20 generates heat to half the temperature of a preset operating temperature for reacting hydrogen vaporized with oxygen, and the high temperature oxygen is It may be waste heat exhausted during rated operation, which is generated at a preset operating temperature when the temperature exceeds half of the preset operating temperature.

Accordingly, in another specific example, when the fuel cell 20 is an alkaline fuel cell, the fuel cell 20 exhausts medium-temperature oxygen from the time it generates heat to 60°C, which is half of the preset operating temperature of 120°C. and while exothermic from 61 ℃ to 120 ℃, high-temperature oxygen is exhausted.

As described above, the medium-temperature oxygen and high-temperature oxygen, which are waste heat exhausted from the fuel cell 20 , may be made in various ways, but hereinafter, a specific example of medium-temperature oxygen and high-temperature oxygen will be described.

In addition, oxygen input to the fuel cell 20 may be pure oxygen or oxygen included in normal air input through an air pump.

The pressure control valve 30 is installed at the front end of the fuel cell 20 on the liquid hydrogen discharge passage 100 to adjust the hydrogen vaporized pressure before being introduced into the fuel cell 20 .

Such a pressure control valve 30 may be a pressure reducing valve for reducing the pressure to a pressure desired by the user by adjusting the pressure of the hydrogen vaporized through the hydrogen vaporized inlet connected to the liquid hydrogen discharge passage 100 with a adjusting screw and a disk.

In this way, when the pressure control valve 30 adjusts the pressure of vaporized hydrogen and the depressurized vaporized hydrogen is exhausted from the vaporized hydrogen exhaust port, the reduced vaporized hydrogen is injected into the fuel cell 20 .

Furthermore, the pressure control valve 30 may be replaced with at least one of a relief valve, a sequence valve, a counterbalance valve, and a pressure switch capable of regulating the pressure of vaporized hydrogen as well as a pressure reducing valve.

The electric damper 40 controls the movement of the fluid to be exchanged with the low-temperature and low-pressure refrigerant input to the evaporator 51 of the heat pump 50 to be described later.

Referring to FIG. 2 , the electric damper 40 includes a damper body 41 , a waste heat inlet 42 , an outdoor air inlet 43 , a fluid exhaust port 44 , a damper blade 45 and a motor 46 .

The damper body 41 is formed in the form of a 3-way damper in which the waste heat inlet 42, the outdoor air inlet 43, and the fluid exhaust port 44 are formed, and has an internal space in which the fluid moves.

The waste heat inlet 42 is connected to the waste heat exhaust passage 200 so that medium-temperature oxygen or high-temperature oxygen is introduced into the inner space of the damper body 41 .

The outdoor air inlet 43 is connected to the outdoor air input passage 300 so that outdoor air is introduced into the inner space of the damper body 41 .

The fluid exhaust port 44 allows the fluid injected into the damper body 41 to be exhausted along the fluid exhaust passage 400 . At this time, the fluid exhausted through the fluid exhaust port 44 may be at least one of outdoor air, air in which the outdoor air and medium temperature oxygen are mixed, and high temperature oxygen.

The damper blade 45 is disposed in the inner space of the damper body 41 , and is rotated according to the driving of the motor 46 .

The damper blade 45 closes the waste heat inlet 42 as shown in FIG. (43) and the fluid exhaust port 44 are rotated to communicate with each other so that outside air is exhausted from the fluid exhaust port (44).

In addition. When the fuel cell 20 exhausts medium-temperature oxygen in the initial operation state, the damper blade 45 has a waste heat inlet 42, an outdoor air inlet 43 and a fluid exhaust port as shown in FIG. 44) is rotated to communicate so that air in which external air and medium temperature oxygen are mixed is exhausted from the fluid exhaust port 44.

And when the fuel cell 20 exhausts high-temperature oxygen in the rated operation state, the damper blade 45 closes the outside air inlet 43 as shown in FIG. 2(c) while closing the waste heat inlet 42 and The fluid exhaust port 44 is rotated to communicate so that high-temperature oxygen is exhausted from the fluid exhaust port 44 .

Furthermore, the damper blade 45 may be provided with a filter for filtering foreign substances that may be included in the outside air. Such a filter is provided to filter foreign substances in the outside air, but it filters foreign substances in the waste heat exhaust passage 200 that moves together with medium-temperature oxygen or high-temperature oxygen and foreign substances in the outdoor air input passage 300 that moves together with the outside air. can be used to

When the motor 46 is driven, it transmits a rotational force to the damper blade 45 so that the damper blade 45 rotates in the inner space of the damper body 41 .

Referring back to FIG. 1 , the heat pump 50 includes vaporization of liquid hydrogen discharged from the liquid hydrogen tank 10 along the liquid hydrogen discharge passage 100 and the fluid exhausted to the outside along the fluid exhaust passage 400 . For cooling, an evaporator 51 , a liquid separator 52 , a compressor 53 , a condenser 54 , a first expansion valve 55 , and a refrigerant passage 500 are provided.

The evaporator 51 is connected to the fluid exhaust passage 400 and is generated from the fluid exhausted along the fluid exhaust passage 400 and the first expansion valve 55 , and then a low-temperature low-pressure refrigerant moved along the refrigerant movement passage 500 . While cooling the fluid through heat exchange of

Here, the medium temperature and low pressure refrigerant means a refrigerant whose temperature is relatively higher than that of the low temperature and low pressure refrigerant.

In addition, the evaporator 51 may be at least one of a dry expansion evaporator, a flooded evaporator, a semi-flooded evaporator, and a liquid recirculation type evaporator. have.

The liquid separator 52 separates the medium-temperature and low-pressure refrigerant generated from the evaporator 51 and then moved along the refrigerant movement path 500 into refrigerant vapor and refrigerant liquid, and at least one of the refrigerant vapor and the refrigerant liquid passes through the refrigerant movement passage ( 500) to be input to the evaporator 51, and the other one is input to the refrigerant moving passage 500 and the compressor 53.

After being separated from the liquid separator 52 , the compressor 53 compresses medium-temperature and low-pressure refrigerant vapor or refrigerant liquid moving along the refrigerant passage 500 to generate a high-temperature and high-pressure refrigerant.

Here, the high-temperature and high-pressure refrigerant means a refrigerant having a relatively higher temperature and pressure than that of the medium-temperature and low-pressure refrigerant.

The condenser 54 is connected to the liquid hydrogen discharge passage 100 and is generated in the liquefied hydrogen and the compressor 53 discharged through the liquid hydrogen discharge passage 100 and then moves along the refrigerant transfer passage 500 of the high temperature and high pressure refrigerant. While vaporizing liquid hydrogen through heat exchange, the medium-temperature and high-pressure refrigerant is generated by condensing the high-temperature and high-pressure refrigerant.

Here, the medium-temperature and high-pressure refrigerant means a refrigerant whose temperature is relatively lower than that of the high-temperature and high-pressure refrigerant.

In addition, the condenser 54 may be at least one of a water-cooled condenser that uses cooling water to perform a condensation process, an air-cooled condenser that emits heat using air, and an evaporative condenser that uses heat absorbed while water evaporates.

The first expansion valve 55 expands the medium-temperature and high-pressure refrigerant that is condensed in the condenser 54 and moves along the refrigerant passage 500 to generate a low-temperature and low-pressure refrigerant, and the low-temperature and low-pressure refrigerant moves through the refrigerant passage 500 . It is moved according to the input to the evaporator (51).

In this case, the low-temperature and low-pressure refrigerant generated from the first expansion valve 55 may vary depending on the type of the medium-temperature and low-pressure refrigerant input from the liquid separator 52 to the compressor 53 .

As a specific example, when the medium temperature and low pressure refrigerant input from the liquid separator 52 to the compressor 53 is refrigerant vapor, the first expansion valve 55 may generate refrigerant vapor of low temperature and low pressure.

As another specific example, when the medium-temperature and low-pressure refrigerant input to the compressor 53 from the liquid separator 52 is a refrigerant liquid, the first expansion valve 55 may generate a low-temperature and low-pressure refrigerant liquid.

Meanwhile, in the present invention, the high temperature of the refrigerant means 40 to 100 ℃, the intermediate temperature means 0 to 40 ℃, and the low temperature means -40 to 10 ℃.

In addition, in the present invention, the high pressure of the refrigerant means 25 bar or more, and the low pressure means 15 bar.

Furthermore, the refrigerant in the present invention may be at least one of chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), hydrofluorocarbon (HFC), hydrofluoroolefin (HFO), hydrocarbon, carbon dioxide, ammonia and water. .

The fuel recoverer 60 recovers the fuel generated through the reaction of the fuel cell 20 and discharged along the fuel recovery passage 600 .

Here, the fuel recovered from the fuel recovery unit 60 means electricity and water generated through the fuel cell 20 and heat that is not exhausted through the waste heat exhaust passage 200 .

The electricity recovered from the fuel recoverer 60 may be supplied to a household, a building, an industrial facility, a means of transportation, etc., and the water may be supplied as hot water to a household, a building, an industrial facility, a means of transportation, etc. , industrial facilities, and transportation may be supplied for heating.

Referring to FIG. 3 , the high-efficiency liquid hydrogen vaporization system using a heat pump according to an embodiment may further include a temperature measuring sensor 70 and a control module 80 .

The temperature sensor 70 controls the temperature of the fuel cell 20 or exhaust from the fuel cell 20 so that the control module 80 controls the rotation of the damper blade 45 according to the operating state of the fuel cell 20 . Measure the temperature of the waste heat.

The installation method of the temperature measuring sensor 70 may vary depending on the temperature measurement method. Specifically, in order to directly measure the temperature of the fuel cell 20 , the inside of the fuel cell 20 or adjacent to the fuel cell 20 . In order to measure the temperature of waste heat exhausted from the fuel cell 20 , it may be installed on the waste heat exhaust passage 200 .

Furthermore, the temperature sensor 70 transmits information about the measured temperature of the fuel cell 20 or the temperature of waste heat exhausted from the fuel cell 20 to the control module 80 .

The control module 80 controls the motor 46 to rotate the damper blade 45 based on the temperature information received from the temperature sensor 70 .

This control module 80, when the temperature sensor 70 directly measures the temperature of the fuel cell 20, based on the temperature information of the fuel cell 20 received from the temperature sensor 70 46) can be controlled.

Accordingly, if the control module 80 determines that the fuel cell 20 is operated before the fuel cell 20 is operated through the temperature information of the fuel cell 20 measured by the temperature sensor 70, as shown in (a) of FIG. The motor 46 may be controlled to rotate the damper blade 45 , and when it is determined that the fuel cell 20 is in the initial operating state, the motor may rotate the damper blade 45 as shown in FIG. 2B . 46 , and when it is determined that the fuel cell 20 is in the rated operation state, the motor 46 may be controlled to rotate the damper blade 45 as shown in FIG. 2C .

In contrast, when the temperature sensor 70 measures the temperature of waste heat exhausted from the fuel cell 20 , the control module 80 uses the temperature information of the waste heat received from the temperature sensor 70 to control the fuel cell ( 20) to control the motor 46 by calculating the temperature.

Accordingly, the control module 80 is preferably configured with an algorithm for calculating the temperature of the fuel cell 20 through the temperature information of the waste heat, and controls the motor 46 according to the calculated temperature of the fuel cell 20 . Since this is the same as the process of controlling the motor 46 based on the temperature information of the fuel cell 20 , a detailed description of the controlling process of the motor 46 will be omitted.

Hereinafter, a high-efficiency liquid hydrogen vaporization system using a heat pump of another embodiment in which the heat pump 50 is modified will be described in detail with reference to FIG. 4 attached.

Furthermore, in the efficiency liquefied hydrogen vaporization system using a heat pump of another embodiment, the remaining components except the heat pump 50, the temperature measuring sensor 70 and the control module 80 are the same as compared to the one embodiment, so below A detailed description of the remaining components except for the heat pump 50 , the temperature measuring sensor 70 and the control module 80 will be omitted.

The heat pump 50 is provided with an evaporator 51 , a liquid separator 52 , a compressor 53 , a condenser 54 , and a first expansion valve 55 , as in the embodiment, and overheating of the compressor 53 . A second expansion valve 56 for preventing and increasing the vaporization efficiency may be further provided.

The second expansion valve 56 communicates with a portion 500a of the refrigerant passage connecting the condenser 54 and the first expansion valve 55 and is installed in the refrigerant input passage 560 connected to the compressor 53. can

The second expansion valve 56 may generate a low-temperature and low-pressure refrigerant by expanding a portion of the medium-temperature and high-pressure refrigerant that moves along a part of the refrigerant passage 500a, and the low-temperature and low-pressure refrigerant flows along the refrigerant input passage 560 . It is possible to prevent overheating of the compressor 53 due to repeating the process of refrigerant vapor or refrigerant liquid by being input to the compressor 53 .

In addition, since the refrigerant flow rate supplied to the evaporator 51 through the compressor 53 along the refrigerant input passage 560 among the total refrigerant flow rate increases, vaporization efficiency may be increased.

In this case, the low-temperature and low-pressure refrigerant generated by the second expansion valve 56 may vary depending on the type of the medium-temperature and low-pressure refrigerant input to the compressor 53 from the liquid separator 52 .

As a specific example, when the medium temperature and low pressure refrigerant input to the compressor 53 from the liquid separator 52 is refrigerant vapor, the second expansion valve 56 may generate refrigerant vapor of low temperature and low pressure.

As another specific example, when the medium-temperature and low-pressure refrigerant input to the compressor 53 from the liquid separator 52 is a refrigerant liquid, the second expansion valve 56 may generate a low-temperature and low-pressure refrigerant liquid.

The temperature sensor 70 not only measures the temperature of the fuel cell 20 or the temperature of waste heat, but also measures the temperature of the compressor 53 , and transmits the temperature information of the compressor 53 to the control module 80 . have.

Accordingly, the temperature sensor 70 is one temperature sensor that measures the temperature of the fuel cell 20 or the temperature of waste heat and the temperature of the compressor 53 , or measures the temperature of the fuel cell 20 or the temperature of waste heat. It may be made of a first temperature sensor and a second temperature sensor for measuring the temperature of the compressor (53).

In the control module 80, since the medium-temperature and high-pressure refrigerant generated in the condenser 54 moves along the refrigerant movement passage 500 and the refrigerant input passage 560, unlike in one embodiment, the temperature measurement sensor 70 receives The first expansion valve 55 and the second expansion valve 56 may be controlled according to the temperature information of the compressor 53 .

As a specific example, when the control module 80 determines that overheating of the compressor 53 has not occurred based on the temperature information of the compressor 53 received from the temperature measurement sensor 70 , the first expansion valve 55 ) is opened and the second expansion valve 56 is closed so that the medium-temperature and high-pressure refrigerant generated in the condenser 54 is introduced into the first expansion valve 55 along the refrigerant passage 500 .

As another specific example, when the control module 80 determines that overheating of the compressor 53 has occurred based on the temperature information of the compressor 53 received from the temperature sensor 70 , the first expansion valve 55 ) and the second expansion valve 56 are opened so that the medium temperature and high pressure refrigerant generated in the condenser 54 and then moved along the part 500a of the refrigerant passage is moved along the refrigerant passage 500, A portion of the high-pressure refrigerant may be moved along the refrigerant injection passage 560 so that the medium-temperature and high-pressure refrigerant is introduced into the first expansion valve 55 and the second expansion valve 56 , respectively.

In this specific example, the compressor 53 is cooled while the liquid hydrogen is vaporized and the fluid is cooled, and the control module 80 controls the opening and closing of the first expansion valve 55 and the second expansion valve 56 . can set the input rate of medium temperature and high pressure refrigerant.

In addition, since the amount of refrigerant required for vaporization of liquid hydrogen and cooling of the fluid in the heat pump 50 is relatively larger than the amount of refrigerant required for cooling of the compressor 53 , the control module 80 operates the first expansion The input rate of the medium temperature and high pressure refrigerant input to the valve 55 may be controlled to be greater than the input rate of the medium temperature high pressure refrigerant input to the second expansion valve 56 , and preferably, the input rate of the medium temperature high pressure refrigerant input to the second expansion valve 56 The medium temperature and high pressure refrigerant input rate and the medium temperature high pressure refrigerant input rate input to the second expansion valve 56 may be at least one of 6:4, 7:3, 8:2, and 9:1.

The high-efficiency liquid hydrogen vaporization system using a heat pump of one embodiment and another embodiment as described above uses waste heat and/or outside air exhausted from the fuel cell 20 to implement a refrigerant cycle of the heat pump 50 to generate liquid hydrogen. It has the effect of vaporizing efficiently.

In addition, the high-efficiency liquefied hydrogen vaporization system using the heat pump of one embodiment and another embodiment selects a fluid to be heat-exchanged with the evaporator 51 according to the operating state of the fuel cell 20, so that the refrigerant cycle of the heat pump 50 is It has the effect of running efficiently.

The detailed description of the preferred embodiments of the present invention disclosed as described above is provided to enable any person skilled in the art to make and practice the present invention. Although the above has been described with reference to preferred embodiments of the present invention, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the scope of the present invention. For example, those skilled in the art can use each configuration described in the above-described embodiments in a way in combination with each other. Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The present invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention. Accordingly, the above detailed description should not be construed as restrictive in all respects but as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention. The present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. In addition, claims that are not explicitly cited in the claims may be combined to form an embodiment or may be included as a new claim by amendment after filing.

10: liquid hydrogen tank, 20: fuel cell,
30: pressure control valve, 40: electric damper,
41: damper body, 42: waste heat inlet,
43: fresh air inlet, 44: fluid exhaust port,
45: damper wing, 46: motor,
50: heat pump, 51: evaporator,
52: liquid separator, 53: compressor,
54: condenser, 55: first expansion valve,
56: a second expansion valve, 60: a fuel recoverer;
70: temperature sensor, 80: control module,
100: liquid hydrogen exhaust passage, 200: waste heat exhaust passage,
300: outside air input passage, 400: fluid exhaust passage,
500: refrigerant moving passage, 560: refrigerant input passage,
600: fuel recovery passage.

Claims (10)

In a high-efficiency liquid hydrogen vaporization system using a heat pump,
liquid hydrogen tank for storing and discharging liquid hydrogen;
a fuel cell for discharging medium temperature oxygen, which is waste heat generated during reaction of hydrogen vaporized through vaporization of the liquid hydrogen with oxygen, or oxygen having a relatively high temperature than the medium temperature, to a waste heat exhaust passage;
A waste heat inlet connected to the waste heat exhaust passage, an outdoor air inlet connected to the outdoor air input passage, and a fluid exhaust port connected to the fluid exhaust passage are formed, and a damper blade for communicating the waste heat inlet and/or the outdoor air inlet and the fluid exhaust port An electric damper having a; and
Produced based on heat exchange with a fluid that is at least one of external air exhausted along a fluid exhaust passage connected to the fluid exhaust port according to the operating state of the fuel cell, air in which the outdoor air and the medium temperature oxygen are mixed, and the high temperature oxygen A high-efficiency liquid hydrogen vaporization system using a heat pump comprising a; a heat pump for vaporizing the liquid hydrogen through the high-temperature and high-pressure refrigerant. The method of claim 1,
The electric damper is
Before the fuel cell is operated, the waste heat inlet is closed through the damper blade, and the outdoor air inlet and the fluid exhaust port are communicated so that the outside air is exhausted to the fluid exhaust passage through the fluid exhaust port. A high-efficiency liquid hydrogen vaporization system using a heat pump. The method of claim 1,
The electric damper is
When the fuel cell is in an initial operation state in which the medium temperature oxygen is exhausted, the waste heat inlet, the outdoor air inlet, and the fluid exhaust port are communicated through the damper blade to allow the air in which the outdoor air and the medium temperature oxygen are mixed to be converted into the fluid A high-efficiency liquid hydrogen vaporization system using a heat pump, characterized in that it is exhausted to the fluid exhaust passage through the exhaust port. 4. The method of claim 3,
The medium temperature oxygen,
High-efficiency liquid hydrogen vaporization system using a heat pump, characterized in that the fuel cell is waste heat exhausted in the initial operation state before the fuel cell generates heat to a preset operation temperature for reacting the hydrogen vaporized with oxygen. The method of claim 1,
The electric damper is
When the fuel cell is in a rated operation state in which the high-temperature oxygen is exhausted, the outside air inlet is closed through the damper blade, and the waste heat inlet and the fluid exhaust port are in communication with each other so that the high-temperature oxygen is supplied through the fluid exhaust port. A high-efficiency liquid hydrogen vaporization system using a heat pump, characterized in that it is exhausted to the fluid exhaust passage. 6. The method of claim 5,
The high-temperature oxygen is
A high-efficiency liquid hydrogen vaporization system using a heat pump, characterized in that the fuel cell is waste heat exhausted in the rated operation state in which heat is generated at a preset operation temperature for reacting the hydrogen vaporized with oxygen. The method of claim 1,
The heat pump is
an evaporator which cools the fluid through heat exchange between the fluid discharged along the fluid exhaust passage and the low-temperature and low-pressure refrigerant and generates a medium-temperature and low-pressure refrigerant through evaporation of the low-temperature and low-pressure refrigerant;
a liquid separator for separating the medium temperature and low pressure refrigerant generated from the evaporator into refrigerant vapor and refrigerant liquid;
a compressor for compressing the refrigerant vapor or refrigerant liquid separated through the liquid separator to generate the high-temperature and high-pressure refrigerant;
a condenser that vaporizes the liquid hydrogen through heat exchange between the high-temperature and high-pressure refrigerant generated through the compressor and the liquid hydrogen, and generates a medium-temperature and high-pressure refrigerant through condensation of the high-temperature and high-pressure refrigerant; and
A high-efficiency liquid hydrogen vaporization system using a heat pump, comprising a; a first expansion valve that expands the medium-temperature and high-pressure refrigerant generated through the condenser to generate the low-temperature and low-pressure refrigerant. 8. The method of claim 7,
The heat pump is
A high-efficiency liquefied hydrogen vaporization system using a heat pump, characterized in that a refrigerant moving passage is provided for moving the refrigerant by connecting the evaporator, the liquid separator, the compressor, the condenser and the first expansion valve. 9. The method of claim 8,
The heat pump is
High-efficiency liquefied hydrogen using a heat pump characterized in that it communicates with a part of the refrigerant passage connecting the condenser and the first expansion valve, and a second expansion valve is installed in the refrigerant input passage connected to the compressor. vaporization system. 10. The method of claim 9,
The second expansion valve,
In order to prevent overheating of the compressor and increase vaporization efficiency, the low-temperature and low-pressure refrigerant generated by expanding a part of the medium-temperature and high-pressure refrigerant moving along a part of the refrigerant passage is introduced into the compressor through the refrigerant input passage. A high-efficiency liquid hydrogen vaporization system using a heat pump, characterized in that.

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