Combined cooling and heating system for shipboard liquefied hydrogen tanks

Abstract

To provide a heating and cooling complex system for a ship liquefied hydrogen tank.SOLUTION: A heating and cooling complex system for a ship liquefied hydrogen tank includes: a water heat source for supplying sea water; a first heat exchanger in which heat exchange with the sea water supplied from the water heat source takes place: an expansion valve connected to the first heat exchanger for lowering a temperature of a refrigerant; a second heat exchanger connected to the expansion valve such that the refrigerant moves to the second heat exchanger and heat exchange therewith takes place; a heat exchange target unit connected to the second heat exchanger to be heated or cooled; a compressor connected between the first heat exchanger and the second heat exchanger and connected to a four-way valve capable of selecting a moving direction of the refrigerant to compress and supply the refrigerant; and a controller capable of controlling the moving direction of the refrigerant by controlling operations of the compressor and the four-way valve.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a combined cooling and heating system for a liquefied hydrogen tank on a ship, and more particularly to a combined cooling and heating system for a liquefied hydrogen tank on a ship that utilizes heat exchange with seawater in a system including a liquefied hydrogen tank and a fuel cell mounted on a ship, and can utilize the heat. [Background technology]

[0002] In recent years, environmental issues have led to restrictions on the use of fossil fuels, and the demand for environmentally friendly alternative energy sources such as renewable electricity and heat has increased in order to achieve carbon neutrality. In particular, in coastal areas, not only is there an increasing demand for new renewable energy sources for energy transition, but there is also an increasing demand to solve this problem through marine energy, which has unlimited potential.

[0003] Seawater temperature difference power generation uses the temperature difference between the cold deep seawater and the hot surface seawater to generate electrical energy.The temperature of deep seawater at a depth of 1,000 m is usually about 5°C, while the temperature of surface water in tropical regions is about 30°C, so this utilizes a temperature difference of 25°C.

[0004] Korean Patent Publication No. 10-0765356 discloses a heat exchange system that utilizes seawater heat.

[0005] The prior art is designed to allow modular expansion of heat exchange pipes without the need for auto-strainers, seawater pumps and filters.

[0006] However, the conventional technology focuses on installing heat exchangers underwater, and there is no coordination system for heat exchange, so each heat exchange target unit is cooled and heated singly, resulting in low heat exchange efficiency. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Registration No. 10-0765356 Summary of the Invention [Problem to be solved by the invention]

[0008] In order to overcome the above-described problems of the conventional technology, an object of one embodiment of the present invention is to provide a combined cooling and heating system for a liquefied hydrogen tank on a ship, which can be used for cooling and heating by utilizing heat exchange with seawater in a system including a liquefied hydrogen tank and a fuel cell installed on a ship. [Means for solving the problem]

[0009] According to one aspect of the present invention, a combined cooling and heating system for a ship's liquefied hydrogen tank on a ship that is equipped with a liquefied hydrogen tank and receives power from a fuel cell includes: a water heat source that supplies seawater; a first heat exchanger that performs heat exchange with the seawater supplied from the water heat source; an expansion valve connected to the first heat exchanger and that lowers the temperature of a refrigerant; a second heat exchanger connected to the expansion valve and through which the refrigerant moves and performs heat exchange; a heat exchange target unit that is connected to the second heat exchanger and that is heated or cooled; a compressor connected between the first heat exchanger and the second heat exchanger and that is connected to a four-way valve that can select the direction of refrigerant movement and that compresses and supplies the refrigerant; and a controller that can control the movement direction of the refrigerant by controlling the operation of the compressor and the four-way valve, wherein the controller controls the flow direction of the refrigerant to heat or cool the heat exchange target unit using the heat of the heat exchange target unit and the heat of the seawater by using the first heat exchanger and the second heat exchanger.

[0010] In order to heat the heat exchange target unit, the controller controls the four-way valve so that the refrigerant moves from the first heat exchanger to the compressor, is compressed, and moves to the second heat exchanger.

[0011] The controller controls the four-way valve so that the refrigerant moves from the second heat exchanger to the compressor, is compressed, and moves to the first heat exchanger in order to cool the heat exchange target unit.

[0012] The four-way valve is equipped with a solenoid device that allows selection of the direction of refrigerant flow.

[0013] The heat exchange target unit includes the liquefied hydrogen tank transported by the ship and a fuel cell that supplies power to the ship. [Effects of the Invention]

[0014] The combined cooling and heating system for a ship's liquefied hydrogen tank according to the present invention has the following advantages.

[0015] First, since seawater is used, it is environmentally friendly and a large amount of heat source can be easily secured.

[0016] Secondly, the thermal energy of each unit can be utilized via the refrigerant, which can be used to cool or heat the unit that is the object of heat exchange.

[0017] Third, the liquefied hydrogen tank and fuel cell can be effectively cooled or heated using seawater and a refrigerant through multiple heat exchangers. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a block diagram showing a combined cooling and heating system for a ship liquefied hydrogen tank according to an embodiment of the present invention. FIG. [Figure 2] 1 is a block diagram showing a combined cooling and heating system for a ship liquefied hydrogen tank according to an embodiment of the present invention. FIG. [Figure 3] 1 is a schematic diagram showing the heating and cooling process for a heat exchange target unit in a combined cooling and heating system for a ship liquefied hydrogen tank according to an embodiment of the present invention. FIG. [Figure 4]10A and 10B are diagrams illustrating an example of temperature control for a heat exchange target unit. DETAILED DESCRIPTION OF THE INVENTION

[0019] The embodiments described below are provided to enable those skilled in the art to easily understand the technical concept of the present invention, and are not intended to limit the present invention. In addition, the matters shown in the accompanying drawings are schematic drawings for easily explaining the embodiments of the present invention, and may differ from the actual embodiment.

[0020] When a component is described as being coupled or connected to another component, it should be understood that the component may be directly coupled or connected to the other component, or there may be other components intervening therebetween.

[0021] FIG. 1 is a schematic diagram showing a combined cooling and heating system for a liquefied hydrogen tank on a ship according to one embodiment of the present invention, and FIG. 2 is a block diagram showing a combined cooling and heating system for a liquefied hydrogen tank on a ship according to one embodiment of the present invention, and showing the direction of refrigerant movement in a four-way valve.

[0022] 1 and 2, a combined cooling and heating system for a liquefied hydrogen tank on a ship according to one embodiment of the present invention is installed on a ship that is equipped with a liquefied hydrogen tank and receives power from a fuel cell, and includes a water heat source 110, a first heat exchanger 120, an expansion valve 130, a second heat exchanger 140, a heat exchange target unit 150, a compressor 160, and a controller 170.

[0023] According to the present invention, the water heat source 110 may further include a seawater reservoir through which seawater flows into the ship and passes or is stored, a raw water pipeline that is a hollow pipe through which seawater is supplied and recovered between the seawater reservoir and the first heat exchanger 120, and a seawater pump that sucks seawater and flows it into the seawater reservoir and the raw water pipeline.

[0024] The first heat exchanger 120 exchanges heat with seawater supplied from the water heat source 110. In addition, the refrigerant that has exchanged heat with the seawater in the first heat exchanger 120 moves to the expansion valve 130 or the compressor 160 to heat or cool the heat exchange target unit 150.

[0025] The expansion valve 130 is connected between the first heat exchanger 120 and the second heat exchanger 140 .

[0026] The expansion valve 130 receives the refrigerant that has undergone heat exchange in the first heat exchanger 120 or the second heat exchanger 140 and expands to reduce the pressure and temperature of the refrigerant.

[0027] The second heat exchanger 140 is connected to the expansion valve 130, the heat exchange target unit 150, and the compressor 160 to perform heat exchange.

[0028] The second heat exchanger 140 releases heat from the refrigerant to the heat exchange target unit 150 to be heated or cooled, or absorbs heat to adjust the temperature of the heat exchange target unit 150 .

[0029] The first heat exchanger 120 and the second heat exchanger 140 are used to heat or cool the heat exchange target unit 150 .

[0030] The heat exchange target unit 150 includes a liquefied hydrogen tank 152 for storing liquefied hydrogen, and a fuel cell 154 for supplying fuel to the ship.

[0031] The liquefied hydrogen tank 152 and the fuel cell 154 are individually connected to the second heat exchanger 140, so that either or both of the liquefied hydrogen tank 152 and the fuel cell 154 can be heated or cooled.

[0032] The liquefied hydrogen tank 152 is in contact with the air that has undergone heat exchange or a pipe through which air flows for heat exchange in the second heat exchanger 140, and it is preferable that the tank neck, to which the wall of the liquefied hydrogen tank 152 is physically connected at room temperature, the support that supports the liquefied hydrogen tank 152, the discharge pipe for discharging the cryogenic liquid stored in the liquefied hydrogen tank 152, and the sensor connection portion of the sensor that is connected to the liquefied hydrogen tank 152 and detects pressure or temperature are all connected so as to be heated or cooled by the refrigerant.

[0033] The combined cooling and heating system for a ship's liquefied hydrogen tank can use heat from seawater or fuel cells as vaporization heat to temporarily heat the connection parts when fuel is supplied to the liquefied hydrogen tank 152, or can be used for defrosting to reduce frost on the surface caused by temperature differences. It can also be used to increase the cooling efficiency of the refrigerant by maintaining the set temperature of the fuel cell 154, or to reduce excessive temperature rise in the fuel cell 154 stack during high output.

[0034] This system combines the benefits of both the fuel cell and the liquefied hydrogen tank. For example, as shown in Figure 4, when a 10°C refrigerant flows in, it has a cooling effect on the fuel cell. When the liquefied hydrogen tank is used on the surface, it has a cooling effect compared to room temperature, and the cryogenic liquid discharge pipe has a relative heating effect. In this case, the cold air in the liquefied hydrogen tank pipeline has a cooling effect on the refrigerant, which indirectly helps cool the fuel cell.

[0035] The compressor 160 is connected to the first heat exchanger 120 and the second heat exchanger 140 by a four-way valve 162. The compressor 160 compresses the refrigerant to raise the temperature of the refrigerant and supplies the refrigerant.

[0036] The four-way valve 162 is connected between the first heat exchanger 120, the second heat exchanger 140, and the compressor 160, and is capable of selecting the direction of refrigerant flow. The four-way valve 162 can change the direction of refrigerant flow according to the heating or cooling control of the controller 170.

[0037] The four-way valve 162 includes four valve flow paths 162-1, 162-2, 162-3, and 162-4, and the four-way valve 162 is configured to open and close the valve flow paths 162-1, 162-2, 162-3, and 162-4 by being operated by a solenoid device 164. The solenoid device 164 slides within the four-way valve 162 to communicate between the second and third valve flow paths 162-2 and 162-3, or between the third and fourth valve flow paths 162-3 and 162-4. The four-way valve 162 may include an auxiliary power source for operating the solenoid device 164.

[0038] This allows the controller 170 to move the solenoid device 164 of the four-way valve 162 so that the high-temperature refrigerant compressed by the compressor 160 moves from the first valve flow path 162-1 through the fourth valve flow path 162-4, or from the first valve flow path 162-1 through the second valve flow path 162-2.

[0039] The controller 170 can control the movement direction of the refrigerant by controlling the operation of the compressor 160 and the four-way valve 162. In addition, the controller 170 is electrically connected to the water heat source 110, the first heat exchanger 120, the second heat exchanger 140, and the heat exchange target unit 150 so as to control their operations, thereby improving heat exchange efficiency.

[0040] The controller 170 according to the present invention may be controlled by a control device that controls the overall operation of the vessel's operations.

[0041] 3(a) and 3(b) are schematic diagrams showing heating and cooling processes using seawater temperature difference according to one embodiment of the present invention.

[0042] Referring to Figures 3(a) and 3(b) together with Figures 1 and 2, the heating and cooling process for a heat exchange target unit in a combined cooling and heating system for a marine liquefied hydrogen tank according to one embodiment of the present invention will be described. In addition to utilizing the heat of the heat exchange target equipment, seawater is used as a heat source for heating or cooling by utilizing the characteristic that water temperature is lower than the atmosphere in summer and higher than the atmosphere in winter.

[0043] 3(a), when heating the heat exchange target unit 150, for example, the controller 170 causes the first heat exchanger 120 to absorb heat from the seawater in the water heat source 110, sends lower temperature seawater to the water heat source 110, and uses the heat absorbed from the seawater in the refrigerant moving through the expansion valve 130 so that the higher temperature refrigerant moves to the compressor 160. Here, the first heat exchanger 120 operates as an evaporator.

[0044] The compressor 160 compresses the refrigerant and moves the high-temperature refrigerant to the second heat exchanger 140. Here, in the four-way valve 162 connected to the compressor 160, a solenoid device 164 is slidable inside the four-way valve 162, and the refrigerant flows from the first heat exchanger 120 into the compressor 160 via the second valve flow path 162-2 and the third valve flow path 162-3, and the refrigerant compressed by the compressor 160 moves to the second heat exchanger 140 via the first valve flow path 162-1 and the fourth valve flow path 162-4 of the four-way valve 162 connected to the compressor 160 (direction A in FIG. 2 ).

[0045] In the second heat exchanger 140, heat is released and the heat of the air is used to heat the heat exchange target unit 150, and lower temperature air is collected. Here, the temperature of the refrigerant is lowered and it moves to the expansion valve 130. Here, the second heat exchanger 140 operates as a condenser.

[0046] The refrigerant that has moved to the expansion valve 130 is further cooled and moves back to the first heat exchanger 120 .

[0047] 3(b), when cooling the heat exchange target unit 150, the controller 170 causes seawater at a higher temperature than the seawater absorbed by the first heat exchanger 120 to move from the water heat source 110 to the first heat exchanger 120, causes heat to be released from the first heat exchanger 120 so that even higher temperature seawater moves to the water heat source 110, and causes the refrigerant moving from the compressor 160 to be cooled and move to the expansion valve 130. Here, the first heat exchanger 120 operates as a condenser.

[0048] Next, the refrigerant, whose temperature has further decreased after passing through the expansion valve 130, moves to the second heat exchanger 140. Relatively low-temperature air is supplied to the heat exchange target unit 150, and higher-temperature air is transferred to the second heat exchanger 140. In the second heat exchanger 140, the refrigerant, whose temperature has increased as a result of absorbing heat, moves to the compressor 160. Here, the second heat exchanger 140 operates as an evaporator.

[0049] In the four-way valve 162 connected to the compressor 160, the solenoid device 164 slides inside the four-way valve 162, and the refrigerant flows from the second heat exchanger 120 into the compressor 160 via the fourth valve flow path 162-4 and the third valve flow path 162-3. The refrigerant compressed by the compressor 160 moves to the first heat exchanger 120 via the first valve flow path 162-1 and the second valve flow path 162-2 of the four-way valve 162 connected to the compressor 160 (direction B in Figure 2).

[0050] Therefore, the combined cooling and heating system for a liquefied hydrogen tank on a ship according to the present invention uses seawater, making it environmentally friendly to use; it can easily secure a large amount of heat source; and it can utilize the thermal energy of each unit via the refrigerant, which can be used to cool or heat the unit that is the target of heat exchange. The liquefied hydrogen tank and fuel cell can be effectively cooled or heated using seawater and refrigerant through multiple heat exchangers.

[0051] It will be understood by those skilled in the art that the present invention can be embodied in other specific forms without changing the technical idea or essential features thereof. Therefore, the above-described embodiments are merely examples of the most suitable embodiments selected from among many possible implementations to facilitate understanding by those skilled in the art, and the technical idea of ​​the present invention is not necessarily limited or restricted to the embodiments presented. It is to be made clear that various changes, additions, and modifications can be made without departing from the technical idea of ​​the present invention, as well as other equivalent embodiments. [Explanation of symbols]

[0052] 110 Water heat source 120 1st heat exchanger 130 Expansion valve 140 Second heat exchanger 150 Heat exchange target unit 152 Liquefied hydrogen tank 154 Fuel Cell 160 Compressor 162 Four-way valve 162-1 1st valve flow path 162-2 2nd valve flow path 162-3 3rd valve flow path 162-4 4th valve flow path 164 Solenoid Device 170 Controller

Claims

1. A combined cooling and heating system for a ship's liquefied hydrogen tank, which is equipped with a liquefied hydrogen tank and is supplied with power by a fuel cell, comprising: a water heat source that supplies seawater; a first heat exchanger for exchanging heat with seawater supplied from the water heat source; an expansion valve connected to the first heat exchanger to reduce a temperature of the refrigerant; a second heat exchanger connected to the expansion valve, through which the refrigerant moves and heat exchange occurs; a heat exchange target unit connected to the second heat exchanger and heated or cooled; a compressor connected between the first heat exchanger and the second heat exchanger, connected to a four-way valve that can select a direction of movement of the refrigerant, and compressing and supplying the refrigerant; a controller that controls the operation of the compressor and the four-way valve to control the direction of movement of the refrigerant, the controller controls the flow direction of the refrigerant to utilize heat of the seawater to heat or cool the heat exchange target unit by the first heat exchanger and the second heat exchanger; the heat exchange target unit includes the liquefied hydrogen tank transported by the ship and a fuel cell that supplies electricity to the ship, a tank neck of the liquefied hydrogen tank, a support base for supporting the liquefied hydrogen tank, a discharge pipe for discharging cryogenic liquid stored in the liquefied hydrogen tank, and a sensor connection portion of a sensor connected to the liquefied hydrogen tank for detecting pressure or temperature, the sensor connection portion being arranged so as to be in contact with a pipe through which a refrigerant flows that undergoes heat exchange in the second heat exchanger.

2. 2. The combined cooling and heating system for a ship's liquefied hydrogen tank according to claim 1, wherein the controller controls the four-way valve so that the refrigerant moves from the first heat exchanger to the compressor, is compressed, and moves to the second heat exchanger in order to heat the heat exchange target unit.

3. 2. The combined cooling and heating system for a ship's liquefied hydrogen tank according to claim 1, wherein the controller controls the four-way valve so that the refrigerant moves from the second heat exchanger to the compressor, is compressed, and moves to the first heat exchanger in order to cool the heat exchange target unit.

4. 2. The combined cooling and heating system for a liquefied hydrogen tank on a ship according to claim 1, wherein the four-way valve is provided with a solenoid device that enables selection of the direction of movement of the refrigerant.

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