Gas vaporization system

Abstract

To provide a gas vaporization system which can stabilize the supply pressure of a vaporized gas while using a heat pump.SOLUTION: A gas vaporization system is constituted by including a heat medium tank 11 for storing a heat medium HC, an evaporation part 12 arranged in the heat medium tank 11 and changing a liquefied gas LG to a vaporized gas VG by a heat exchange with the heat medium HC, a flow-in pipe 13 for making the liquefied gas flow to the evaporation part 12, a flow-out pipe 14 for making the vaporized gas VG flow out of the evaporation part 12, and a vapor compression type heat pump circuit having a compressor, a heat radiation part, an expansion part, and a heat absorption part. The gas vaporization system also comprises a main heater 15 for heating the heat medium HC by a thermal output from the heat radiation part, and a controller 16 for controlling the thermal output of the main heater 15. The controller 16 controls a heating amount of the heat medium HC on the basis of a detection result of a state amount having a correlation with the vaporized gas VG or the pressure of the vaporized gas VG in the heat medium HC.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a gas vaporization system for converting liquefied gas into vaporized gas.

Background Art

[0002] Conventionally, as vaporization equipment for liquefied gases such as LNG (liquefied natural gas) and LPG (liquefied petroleum gas), a hot water heating type system is known. In Patent Document 1, a vaporization system (Figure 2) in which an evaporation pipe and an evaporation cylinder are installed inside a hot water tank and the stored water is heated by a heater arranged at the lower part of the hot water tank, and a vaporization system (Figure 1) in which the stored water is heated by a heater attached to the outer surface of the hot water tank are described. Further, in Patent Document 2, a vaporization system is described in which an evaporation pipe is installed inside a hot water tank and the stored water is circulated while being heated by a hot water boiler. In the systems described in Patent Documents 1 and 2, in the process of the liquefied gas passing through the inside of the evaporation pipe, it changes into vaporized gas by heat exchange with hot water.

[0003] In addition, in Patent Document 3, a vaporization system is described in which water (second liquid) is circulated to the vaporization equipment while being heated by a heat pump device, or water (first liquid) is circulated to the vaporization equipment while being heated by a ground heat exchanger and / or an air heat exchanger. During the operation of the heat pump device, the water (first liquid) heated by the ground heat exchanger or the air heat exchanger serves as the heat source fluid of the heat pump device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Fossil fuels such as LNG and LPG will emit carbon dioxide due to the consumption of end-users. From the perspective of reducing the total carbon dioxide emissions including the supply chain of these fuel gases, it is desirable to suppress the usage amount of fossil fuels in the vaporization process.

[0006] In the vaporization system described in Patent Document 1, since the heating device for hot water generation is an electric heater, when fossil fuel is used as the primary energy source of the supplied power, it will lead to an increase in the total carbon dioxide emissions. Although renewable energy such as sunlight and wind power can also be used as the primary energy source of the supplied power, backup power generation using fossil fuel is required to continue power supply even after sunset or when there is no wind.

[0007] Also, in the vaporization system described in Patent Document 2, since the heating device for hot water generation is a combustion boiler and propane gas, which is a fossil fuel, is used, it will lead to an increase in the total carbon dioxide emissions. In the vaporization system described in Patent Document 3, since the heating device for hot water generation is a heat pump device, it is expected to obtain a high effect in suppressing the total carbon dioxide emissions.

[0008] By the way, when utilizing a hot water heating type vaporization system, from the perspective of gas utilization equipment, it is desirable that the supply pressure of the vaporized gas is stable at a high level. However, in the conventional vaporization system using a hot water heat pump, it only adjusts the temperature of the hot water flowing into the hot water tank, and the stability of the supply pressure cannot be said to be sufficient.

[0009] In view of the above problems, an object of the present invention is to provide a gas vaporization system that can stabilize the supply pressure of the vaporized gas while utilizing a heat pump.

Means for Solving the Problems

[0010] The gas vaporization system according to the present invention includes a heat medium tank for storing a heat medium, an evaporation unit disposed inside the heat medium tank for vaporizing a liquefied gas into a vaporized gas by heat exchange with the heat medium, an inflow pipe for allowing the liquefied gas to flow into the evaporation unit, an outflow pipe for allowing the vaporized gas to flow out from the evaporation unit, and a vapor compression type heat pump circuit having a compressor, a heat dissipation unit, an expansion unit, and a heat absorption unit. The system further includes a main heating device for heating the heat medium by the heat output from the heat dissipation unit, and a controller for controlling the heat output of the main heating device. The controller is configured to control the heating amount of the heat medium based on the detection result of a state quantity having a correlation with the pressure of the vaporized gas in the vaporized gas or the heat medium. According to this configuration, it is possible to stabilize the supply pressure of the vaporized gas while utilizing the heat pump.

[0011] More specifically, as the above configuration, a first pressure detection unit for detecting the pressure of the vaporized gas flowing through the outflow pipe may be provided, and the controller may be configured to control the heat output of the main heating device such that the detected pressure of the first pressure detection unit becomes a set target pressure. More specifically, as the above configuration, a first temperature detection unit for detecting the temperature of the vaporized gas flowing through the outflow pipe may be provided, and the controller may be configured to control the heat output of the main heating device such that the detected temperature of the first temperature detection unit becomes a set target temperature.

[0012] More specifically, as the above configuration, a second temperature detection unit for detecting the temperature of the heat medium existing in the vicinity of the evaporation unit may be provided, and the controller may be configured to control the heat output of the main heating device such that the detected temperature of the second temperature detection unit becomes a set second target temperature. More specifically, as the above configuration, a third temperature detection unit for detecting the temperature of the heat medium before heating in the heat dissipation unit and a fourth temperature detection unit for detecting the temperature of the heat medium after heating in the heat dissipation unit may be provided, and the controller may be configured to control the heat output of the main heating device such that the detected temperature difference between the fourth temperature detection unit and the third temperature detection unit becomes a set target temperature difference.

[0013] More specifically, as the above configuration, the heat dissipation unit is disposed inside the heat medium tank in a state where it can exchange heat with the heat medium, and the controller may be configured to control the heat output of the main heating device by adjusting the rotation speed of the compressor. More specifically, as the above configuration, the main heating device includes a first circulation supply pipe that sends the heat medium heated by the heat dissipation unit to the heat medium tank, a first circulation return pipe that returns the heat medium after heat utilization in the heat medium tank to the heat dissipation unit, and a first circulation pump provided in the first circulation supply pipe. The controller may be configured to control the heat output of the main heating device by driving the first circulation pump at a predetermined rotation speed and adjusting the rotation speed of the compressor.

[0014] More specifically, as the above configuration, the main heating device includes a heat exchange unit that exchanges heat between the heat medium and an intermediate medium, a second circulation supply pipe that sends the intermediate medium heated by the heat dissipation unit to the high-temperature side of the heat exchange unit, a second circulation return pipe that returns the intermediate medium after heat utilization on the high-temperature side of the heat exchange unit to the heat dissipation unit, a second circulation pump provided in the second circulation supply pipe, a third circulation supply pipe that sends the heat medium heated on the low-temperature side of the heat exchange unit to the heat medium tank, a third circulation return pipe that returns the heat medium after heat utilization in the heat medium tank to the low-temperature side of the heat exchange unit, and a third circulation pump provided in the third circulation supply pipe. The controller may be configured to control the heat output of the main heating device by driving the second circulation pump and the third circulation pump at a predetermined rotation speed and adjusting the rotation speed of the compressor.

[0015] More specifically, in the above configuration, the main heating device includes a first heat radiating part in the front stage and a second heat radiating part in the rear stage as the heat radiating part. The heat medium is heated by the heat output from the first heat radiating part, and the liquefied gas is heated by the heat output from the second heat radiating part. It is configured with a first branch pipe that sends the liquefied gas flowing through the upstream side of the inflow pipe to the second heat radiating part, a second branch pipe that returns the liquefied gas preheated by the second heat radiating part to the downstream side of the inflow pipe, a gas flow rate adjusting part that adjusts the flow rate of the liquefied gas sent from the inflow pipe to the first branch pipe, a second pressure detecting part that detects the pressure of the liquefied gas before flowing into the evaporation part, and a fifth temperature detecting part that detects the temperature of the liquefied gas before flowing into the evaporation part. The controller may be configured to obtain the saturation temperature of the liquefied gas at the detected pressure of the second pressure detecting part and control the gas flow rate adjusting part so that the detected temperature of the fifth temperature detecting part is lower than the saturation temperature.

[0016] More specifically, in the above configuration, it includes a booster that boosts the vaporized gas flowing through the outflow pipe, and a capacity control valve provided on the suction side of the booster to adjust the suction pressure. The controller may be configured to control the opening degree of the capacity control valve so that the internal pressure of the evaporation part becomes lower than the target pressure. More specifically, in the above configuration, it may be configured to recover the compression heat generated during the pressure boosting process in the booster from the vaporized gas discharged from the booster and supply the recovered compression heat to the liquefied gas, the heat medium, or the heat absorption part.

[0017] More specifically, in the above configuration, it may include a heat recovery part that allows the vaporized gas discharged from the booster to flow through and recovers the compression heat generated during the pressure boosting process in the booster by heat exchange with the heat medium, a fourth circulation forward pipe that sends the heat medium heated by the heat recovery part to the heat medium tank, a fourth circulation return pipe that returns the heat medium after heat utilization in the heat medium tank to the heat recovery part, and a fourth circulation pump provided on the fourth circulation forward pipe.

[0018] More specifically, as the above configuration, there may be provided a heat recovery unit configured to circulate the vaporized gas discharged from the booster and recover the compression heat generated during the pressure boosting process in the booster by heat exchange with an intermediate medium; a fifth circulation supply pipe configured to send the intermediate medium heated by the heat recovery unit to the endothermic unit; a fifth circulation return pipe configured to return the intermediate medium after heat absorption in the endothermic unit to the heat recovery unit; and a fifth circulation pump provided in the fifth circulation supply pipe.

[0019] More specifically, as the above configuration, there may be provided an auxiliary heating device configured to heat the heat medium; a sixth circulation supply pipe configured to send the heat medium heated by the auxiliary heating device to the heat medium tank; a sixth circulation return pipe configured to return the heat medium after heat utilization in the heat medium tank to the auxiliary heating device; a sixth circulation pump provided in the sixth circulation supply pipe; a sixth temperature detection unit configured to detect the temperature of the heat source fluid supplied to the endothermic unit; and a seventh temperature detection unit configured to detect the temperature of the heat medium after heating by the auxiliary heating device. The auxiliary heating device includes a combustion type hot water boiler or an electric heater, and the controller is configured to operate the auxiliary heating device when the detected temperature of the sixth temperature detection unit is lower than a set reference temperature, and control the heat output of the auxiliary heating device so that the detected temperature of the seventh temperature detection unit reaches a set base temperature during operation of the auxiliary heating device.

Advantages of the Invention

[0020] According to the gas vaporization system of the present invention, it is possible to stabilize the supply pressure of the vaporized gas while not using a heat pump.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0022] Each embodiment of the present invention will be described below with reference to the drawings.

[0023] 1. First Embodiment First, the first embodiment will be described. FIG. 1 schematically shows the configuration of a gas vaporization system 1 according to the first embodiment. As shown in this figure, the gas vaporization system 1 includes a heat medium tank 11, an evaporation section 12, an inflow pipe 13, an outflow pipe 14, a main heating device 15, a controller 16, a pressure adjustment unit 17, and a capillary tube 18. The gas vaporization system 1 heats the liquefied gas LG (for example, LNG or LPG) supplied from an external supply source to convert it into vaporized gas VG, and serves to supply this vaporized gas VG to an external supply destination (for example, a device using the vaporized gas VG).

[0024] The heat medium tank 11 is a tank for storing the heat medium HC. In this embodiment, water (hot water) is adopted as the heat medium HC, but the specific type of the heat medium HC is not particularly limited as long as it does not deviate from the gist of the present invention. A heat insulating material is arranged on the outer wall of the heat medium tank 11 so as to suppress the heat dissipation of the heat medium HC as much as possible.

[0025] The evaporation section 12 is arranged inside the heat medium tank 11 and vaporizes the liquefied gas LG into the vapor gas VG by heat exchange with the heat medium HC. In the example of this embodiment, the evaporation section 12 is composed of an evaporation pipe 12a and an evaporation cylinder 12b. The evaporation pipe 12a is a coiled heat transfer pipe and is arranged so that the flowing-in liquefied gas LG flows in a downward flow. The evaporation cylinder 12b serves as a gas-liquid separator for increasing the dryness of the vapor gas VG generated by the evaporation pipe 12a and also serves to reheating the separated moisture.

[0026] The inflow pipe 13 is configured to allow the liquefied gas LG supplied from an external supply source to flow into the evaporation section 12. The outflow pipe 14 is configured to allow the vapor gas VG to flow out from the evaporation section 12 to an external supply destination.

[0027] The main heating device 15 is a device for heating the heat medium HC configured to include a heat pump circuit 15X. The heat pump circuit 15X is a vapor compression type heat pump circuit in which a compressor 15a, a heat dissipation section 15b, an expansion section 15c, and a heat absorption section 15d are annularly connected by a refrigerant circulation line. A refrigerant R (for example, a gas refrigerant such as a fluorocarbon gas) flows in the refrigerant circulation line of the heat pump circuit 15X. The main heating device 15 can heat the heat medium HC by the heat output from the heat dissipation section 15b.

[0028] The compressor 15a has a motor as a drive source and compresses the gaseous refrigerant R into a high-temperature and high-pressure state. The rotation speed of the compressor 15a can be controlled by a controller 16. By adjusting the rotation speed of the compressor 15a, it is possible to adjust the heat output from the heat dissipation section 15b (that is, the heat output of the main heating device 15).

[0029] The heat radiating part 15b is a refrigerant condenser that condenses the gaseous refrigerant R sent from the compressor 15a, radiates the latent heat and sensible heat of the refrigerant R, and can heat the heat medium HC. The heat radiating part 15b of the present embodiment is arranged inside the heat medium tank 11 in a state where it can exchange heat with the heat medium HC. That is, the heat transfer surface of the heat radiating part 15b is immersed in the heat medium HC held in the heat medium tank 11.

[0030] The heat radiating part 15b of the present embodiment is a so-called heat transfer tube, and spiral fins or serrated fins that promote heat exchange may be provided on the surface. This heat transfer tube may be a coiled or folded heat transfer tube. Also, from the viewpoint of enhancing the heat transfer efficiency, it is preferable to arrange the heat radiating part 15b (heat transfer tube) close to the evaporation part 12 (heat transfer tube). In this way, the gas vaporization system 1 of the present embodiment can also be manufactured as a compact unit integrating the heat medium tank 11 and the heat pump circuit 15X. Also, even if the refrigerant R leaks from the heat pump circuit 15X, the leaked refrigerant R stays in the heat medium tank 11, so the dissipation into the atmosphere is suppressed.

[0031] The expansion part 15c reduces the pressure and temperature of the refrigerant R by passing the liquid refrigerant R sent from the heat radiating part 15b. The heat absorbing part 15d is an evaporator to which the heat source fluid HS is supplied, absorbs heat from the heat source fluid HS, and evaporates the liquid refrigerant R sent from the expansion valve 13. The type of the heat source fluid HS (heat source for the heat absorbing part 15d) may be either air or water, and other fluids may be used as long as the gist of the present invention is not deviated from.

[0032] The controller 16 controls the heat output of the main heating device 15. The more specific form of the control performed by the controller 16 will be described in detail again. The pressure adjustment unit 17 includes a thermovalve, an abnormal pressure prevention valve, a vaporization pressure adjustment valve, and the like. The thermovalve shuts off the supply of the liquefied gas LG when the temperature of the heat medium HC is low. The abnormal pressure prevention valve shuts off the supply of the liquefied gas LG when the pressure of the vaporized gas VG is too high. The vaporization pressure adjustment valve lowers the pressure of the liquefied gas LG to a set value and causes it to flash (re-evaporate).

[0033] One end of the capillary tube 18 is disposed inside the evaporation cylinder 12b and is used to release the liquefied gas LG from the evaporation cylinder 12b, for example, when the gas vaporization system 1 is stopped for a long period. When releasing the liquefied gas LG, the drain valve 18a provided in the capillary tube 18 is opened, and after the release, it is closed again.

[0034] In the gas vaporization system 1 described above, the low-temperature liquefied gas LG flowing from the inflow pipe 13 into the evaporation section 12 is vaporized by being heated through heat exchange with the high-temperature heat medium HC in the process of flowing through the evaporation pipe 12a and changes into wet gas. Note that the heat medium HC after heat exchange is cooled by the heat of vaporization of the liquefied gas LG and thus its temperature drops, but it is heated by the main heating device 15 and returns to a high-temperature state. The wet gas flowing out of the evaporation pipe 12a is separated into gas and liquid in the evaporation cylinder 12b to become dry gas, and flows out as the vaporized gas VG whose pressure is adjusted from the outflow pipe 14. The moisture separated in the evaporation cylinder 12b is reheated by the high-temperature heat medium HC in the process of being accumulated in the evaporation cylinder 12b and becomes dry gas.

[0035] When controlling the heat output of the main heating device 15, the controller 16 controls the heating amount of the heat medium HC based on the detection result of a state quantity (typically, pressure or temperature) that has a correlation with the pressure of the vaporized gas VG in the vaporized gas VG or the heat medium HC. More specifically, the controller 16 adjusts the rotational speed of the compressor 15a based on the detection result of the state quantity to adjust the heat output of the main heating device 15 and control the heating amount of the heat medium HC. Here, more specific adjustment methods for the rotational speed of the compressor 15a by the controller 16 will be described below by taking the first to fourth adjustment methods as examples.

[0036] (1) First adjustment method First, the first adjustment method will be described. FIG. 2 schematically shows a more detailed configuration of the vaporization system 1 when the first adjustment method is adopted. As shown in this figure, a first pressure detection unit 19a is provided in the vaporization system 1 when the first adjustment method is adopted. The first pressure detection unit 19a detects the pressure of the vaporized gas VG (dry gas) flowing through the outflow pipe 14 and continuously transmits the information of the detected pressure P1 to the controller 16.

[0037] On the other hand, the controller 16 controls the heat output of the main heating device 15 by adjusting the rotational speed of the compressor 15a so that the detected pressure P1 becomes a preset target pressure Pg1. For the control of this heat output, feedback control (PID control) using a PID algorithm with the detected pressure P1 as the PV value and the target pressure Pg1 as the SV value is used. Thereby, the vaporized gas VG adjusted to the target pressure Pg1 can be supplied to the supply destination of the vaporized gas VG.

[0038] (2) Second adjustment method Next, the second adjustment method will be described. FIG. 3 schematically shows a more detailed configuration of the vaporization system 1 when the second adjustment method is adopted. As shown in this figure, a first temperature detection unit 19b is provided in the vaporization system 1 when the second adjustment method is adopted. The first temperature detection unit 19b detects the temperature of the vaporized gas VG (dry gas) flowing through the outflow pipe 14 and continuously transmits the information of the detected temperature T1 to the controller 16.

[0039] On the other hand, the controller 16 controls the heat output of the main heating device 15 by adjusting the rotational speed of the compressor 15a so that the detected temperature T1 becomes a preset target temperature Tg1. This target temperature Tg1 is set as a saturation temperature calculated from the required supply pressure of the vaporized gas VG (dry gas), or as a superheat temperature exceeding this saturation temperature by a predetermined temperature difference (for example, 1 to 2°C). For the control of the heat output, PID control with the detected temperature T1 as the PV value and the target temperature Tg1 as the SV value is used. Thereby, the vaporized gas VG adjusted to a predetermined pressure determined by the target temperature Tg1 can be supplied to the supply destination of the vaporized gas VG.

[0040] (3) Third adjustment method Next, the third adjustment method will be described. FIG. 4 schematically shows a more detailed configuration of the vaporization system 1 when the third adjustment method is employed. As shown in this figure, a second temperature detection unit 19c is provided in the vaporization system 1 when the third adjustment method is employed. The second temperature detection unit 19c detects the temperature of the heat medium HC existing in the vicinity of the evaporation unit 12 and continuously transmits information on the detected temperature T2 to the controller 16.

[0041] On the other hand, the controller 16 controls the heat output of the main heating device 15 by adjusting the rotational speed of the compressor 15a so that the detected temperature T2 becomes a preset target temperature Tg2. By this control, the heat absorption amount associated with the vaporization of the liquefied gas LG and the heat generation amount in the heat pump circuit 15X can be balanced. For the control of the heat output, PID control with the detected temperature T2 as the PV value and the target temperature Tg2 as the SV value is used. Thereby, the vaporized gas VG adjusted to the saturation pressure determined by the target temperature Tg2 can be supplied to the supply destination of the vaporized gas VG.

[0042] Note that the second temperature detection unit 19c is preferably provided, for example, near the surface of the gas inlet region of the evaporation pipe 12a where the vaporization of the liquefied gas LG starts and the latent heat of vaporization is the largest. That is, by providing the second temperature detection unit 19c so as to detect the temperature at the position where the cooling of the heat medium HC progresses most, it becomes possible to supply heat to the evaporation pipe 12a without excess or deficiency.

[0043] (4) Fourth adjustment method Next, the fourth adjustment method will be described. FIG. 5 schematically shows a more detailed configuration of the vaporization system 1 when the fourth adjustment method is adopted. As shown in this figure, in the vaporization system 1 when the fourth adjustment method is adopted, a third temperature detection unit 19d and a fourth temperature detection unit 19e are provided. The third temperature detection unit 19d detects the temperature of the heat medium HC before heating in the heat radiation unit 15b and continuously transmits information on the detected temperature T3 to the controller 16. The fourth temperature detection unit 19e detects the temperature of the heat medium HC after heating in the heat radiation unit 15b and continuously transmits information on the detected temperature T4 to the controller 16.

[0044] When the heat radiation unit 15b is disposed inside the heat medium tank 11 as in the present embodiment, in consideration of the convection of the heat medium HC, the third temperature detection unit 19d is disposed at the lowest temperature location inside the heat medium tank 11 (for example, near the surface of the gas inlet region of the evaporation pipe 12a), and the fourth temperature detection unit 19e is disposed at the highest temperature location inside the heat medium tank 11 (for example, near the surface of the refrigerant inlet region of the heat radiation pipe).

[0045] On the other hand, the controller 16 controls the heat output of the main heating device 15 by adjusting the rotational speed of the compressor 15a so that the difference between the detected temperature T4 and the detected temperature T3 (detected temperature difference T5) becomes a preset target temperature difference Tg3. By this control, it becomes possible to continuously supply a constant heating amount to the liquefied gas LG flowing through the evaporation section 12. For the control of the heat output, PID control with the detected temperature difference T5 as the PV value and the target temperature difference Tg3 as the SV value is used. Thereby, a gasification gas VG in an amount determined by the heating amount of the heat pump circuit 15X can be continuously generated for the supply destination of the gasification gas VG, and the gasification gas VG adjusted to the required pressure can be supplied.

[0046] When the heat dissipation section 15b is disposed outside the heat medium tank 11 (for example, refer to the second and third embodiments described later), a third temperature detection section 19d is disposed to detect the temperature of the heat medium HC flowing out of the heat medium tank 11, and a fourth temperature detection section 19e is disposed to detect the temperature of the heat medium HC flowing into the heat medium tank 11. The detected temperature difference between the fourth temperature detection section 19e and the third temperature detection section 19d corresponds to the amount of cooling of the heat medium HC due to the heat of vaporization of the liquefied gas LG.

[0047] 2. Second Embodiment Next, the second embodiment will be described. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted.

[0048] FIG. 6 schematically shows the configuration of the gas vaporization system 2 according to the second embodiment. As shown in this figure, in the gas vaporization system 2, the main heating device 15 has a first circulation path L1 configured to interpose the inside of the heat medium tank 11 and the heat dissipation section 15b, and it is possible to circulate the heat medium HC in the first circulation path L1.

[0049] The first circulation path L1 includes a first circulation supply pipe 21 that sends the heat medium HC heated by the heat dissipation part 15b to the heat medium tank 11, and a first circulation return pipe 22 that returns the heat medium HC after heat utilization in the heat medium tank 11 to the heat dissipation part 15b. A first circulation pump 23 for circulating the heat medium HC in the first circulation path L1 is provided in the first circulation supply pipe 21.

[0050] Thus, in the second embodiment, the heat dissipation part 15b is disposed outside the heat medium tank 11 and is connected to the heat medium tank 11 by the first circulation supply pipe 21 and the first circulation return pipe 22. For example, a plate heat exchanger is used as the heat dissipation part 15b of the present embodiment. While the refrigerant R flows through the high-temperature side flow path, the heat medium HC flows through the low-temperature side flow path. Thereby, since a design in which the heat medium tank 11 and the heat pump circuit 15X are separated becomes possible, it is possible to select a heat pump circuit 15X according to the heat exchange amount in the heat medium tank 11 and combine it with the heat medium tank 11 to constitute the gas vaporization system 2.

[0051] Also, in the second embodiment, the controller 16 performs PID control of the heat output of the main heating device 15 by driving the first circulation pump 23 at a predetermined rotation speed and adjusting the rotation speed (MV value) of the compressor 15a. Thereby, the heat medium HC is circulated in the first circulation path L1, the heat medium HC is appropriately heated by the heat output from the heat dissipation part 15b, and the heat output can be made to quickly follow the detected pressure and detected temperature.

[0052] 3. Third Embodiment Next, the third embodiment will be described. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted.

[0053] Figure 7 schematically shows the configuration of the gas vaporization system 3 according to the third embodiment. As shown in this figure, in the gas vaporization system 3, the main heating device 15 includes a heat exchange section (intermediate heat exchanger) 31 that exchanges heat between the heat medium HC and the intermediate medium MC, a second circulation path L2 configured to interpose the heat dissipation section 15b and the heat exchange section 31, and a third circulation path L3 configured to interpose the inside of the heat medium tank 11 and the heat exchange section 31.

[0054] The second circulation path L2 is a path for circulating the intermediate medium MC, and the third circulation path L3 is a path for circulating the heat medium HC. In this embodiment, water (warm water) is adopted as the intermediate medium MC, but the specific type of the intermediate medium MC is not particularly limited as long as it does not depart from the gist of the present invention.

[0055] The second circulation path L2 includes a second circulation forward pipe 32 that sends the intermediate medium MC heated by the heat dissipation section 15b to the high-temperature side of the heat exchange section 31, and a second circulation return pipe 33 that returns the intermediate medium MC after heat utilization on the high-temperature side of the heat exchange section 31 to the heat dissipation section 15b. A second circulation pump 34 for circulating the intermediate medium MC in the second circulation path L2 is provided in the second circulation forward pipe 32.

[0056] The third circulation path L3 includes a third circulation forward pipe 35 that sends the heat medium HC heated on the low-temperature side of the heat exchange section 31 to the heat medium tank 11, and a third circulation return pipe 36 that returns the heat medium HC after heat utilization in the heat medium tank 11 to the low-temperature side of the heat exchange section 31. A third circulation pump 37 for circulating the heat medium HC in the third circulation path L3 is provided in the third circulation forward pipe 35.

[0057] Thus, in the third embodiment, the heat dissipation part 15b is arranged outside the heat medium tank 11, the heat dissipation part 15b and the heat exchange part 31 are connected by the second circulation forward pipe 33 and the second circulation return pipe 34, and the heat exchange part 31 and the heat medium tank 11 are connected by the third circulation forward pipe 35 and the third circulation return pipe 36. The heat dissipation part 15b of this embodiment uses, for example, a plate type heat exchanger, while the refrigerant R flows through the high temperature side flow path and the intermediate medium MC flows through the low temperature side flow path. Also, the heat exchange part 31 uses, for example, a plate type heat exchanger, while the intermediate medium MC flows through the high temperature side flow path and the heat medium HC flows through the low temperature side flow path.

[0058] As a result, it is possible to design by separating the heat medium tank 11 and the heat pump circuit 15X. Therefore, it is possible to select a heat pump circuit 15X according to the heat exchange amount in the heat medium tank 11 and combine it with the heat medium tank 11 to form the gas vaporization system 3. Also, even if the refrigerant R leaks due to damage to the heat dissipation part 15b, leakage to the heat medium tank 11 side is prevented at the heat exchange part 31, so the dissipation of the refrigerant R into the atmosphere is suppressed.

[0059] Also, in the third embodiment, the controller 16 drives the second circulation pump 34 and the third circulation pump 37 at a predetermined rotational speed, and adjusts the rotational speed (MV value) of the compressor 15a to perform PID control of the heat output of the main heating device 15. As a result, the intermediate medium MC is circulated in the second circulation path L2 and the heat medium HC is circulated in the third circulation path L3, and while appropriately heating the heat medium HC with the heat output from the heat dissipation part 15b, the heat output can be made to rapidly follow the detected pressure and detected temperature.

[0060] 4. Fourth Embodiment Next, the fourth embodiment will be described. In the following description, emphasis will be placed on explaining matters different from the first embodiment, and descriptions of matters common to the first embodiment may be omitted.

[0061] FIG. 8 schematically shows the configuration of the gas vaporization system 4 according to the fourth embodiment. As shown in this figure, in the main heating device 15 of the gas vaporization system 4, the heat radiation part 15b includes a first heat radiation part (refrigerant condenser) 15b1 in the front stage and a second heat radiation part (refrigerant subcooler) 15b2 in the rear stage. The second heat radiation part 15b2 has the role of preheating the liquefied gas LG.

[0062] The gas vaporization system 4 also includes a first branch pipe 41 that sends the liquefied gas LG flowing through the upstream side of the inflow pipe 13 to the second heat radiation part 15b2, a second branch pipe 42 that returns the liquefied gas LG preheated by the second heat radiation part 15b2 to the downstream side of the inflow pipe 13, a gas flow rate adjustment part (three-way valve) 43 that adjusts the flow rate of the liquefied gas LG sent from the inflow pipe 13 to the first branch pipe 41, a second pressure detection part 44 that detects the pressure of the liquefied gas LG before flowing into the evaporation part 12, and a fifth temperature detection part 45 that detects the temperature of the liquefied gas LG before flowing into the evaporation part 12.

[0063] The main heating device 15 is configured to heat the heat medium HC by the heat output from the first heat radiation part 15b1 and heat the liquefied gas LG by the heat output from the second heat radiation part 15b2. For the second heat radiation part 15b2, for example, a plate heat exchanger is used. While the refrigerant R flows through the high-temperature side flow path, the liquefied gas LG flows through the low-temperature side flow path.

[0064] The liquefied gas LG flowing through the upstream side of the inflow pipe 13 is sent to the second heat radiation part 15b2 through the first branch pipe 41, while the liquefied gas LG preheated by the second heat radiation part 15b2 is returned to the downstream side of the inflow pipe 13 through the second branch pipe 42. Note that the flow rate of the liquefied gas LG sent from the inflow pipe 13 to the first branch pipe 41 can be adjusted by changing the state (opening degree of the three-way valve) of the gas flow rate adjustment part 43.

[0065] While calculating the saturation temperature (boiling point) of the liquefied gas LG at the detected pressure Px of the second pressure detection unit 44, the controller 16 performs PID control to adjust the state (MV value) of the gas flow rate adjustment unit 43 so that the detected temperature Tx (PV value) of the fifth temperature detection unit 45 becomes a preheating temperature (SV value) lower than the saturation temperature. As a result, the liquefied gas LG can be quickly preheated to near the boiling point, enabling miniaturization of the evaporation unit 12 and the heat medium tank 11.

[0066] 5. Fifth Embodiment Next, the fifth embodiment will be described. In the following description, emphasis will be placed on the description of matters different from the first embodiment, and the description of matters common to the first embodiment may be omitted.

[0067] FIG. 9 schematically shows the configuration of a gas vaporization system 5 according to the fifth embodiment. As shown in this figure, the gas vaporization system 5 includes a booster 51 and a capacity control valve 52. The booster 51 is a gas compressor that compresses and boosts the vaporized gas VG flowing through the outflow pipe 14. The capacity control valve 52 is provided on the suction side of the booster 51 and adjusts the suction pressure of the booster 51.

[0068] In the fifth embodiment, as a method for adjusting the rotational speed of the compressor 15a by the controller 16, the first adjustment method (refer to FIG. 2) described above is adopted, and the first pressure detection unit 19a is provided. This first pressure detection unit 19a detects the internal pressure of the evaporation unit 12 and continuously transmits information on the detected pressure P1 to the controller 16. Then, the controller 16 controls the opening degree of the capacity control valve 52 so that the internal pressure of the evaporation unit 12 detected by the first pressure detection unit 19a becomes lower than the target pressure Pg1.

[0069] Thus, in this embodiment, by controlling the opening degree of the capacity control valve 52 so that the internal pressure of the evaporation section 12 becomes lower than the target pressure Pg1, the boiling point when the liquefied gas LG vaporizes is decreased. As a result, the heating amount required in the heat pump circuit 15X (i.e., the heat absorption amount in the evaporation section 12) is reduced, and thus the width of the temperature distribution in the heat medium tank 11 also becomes smaller. Consequently, while efficiently vaporizing the liquefied gas LG in a short time, the supply pressure of the vaporized gas VG can be made more stable.

[0070] Further, the gas vaporization system 5 includes a heat recovery section (a heat exchanger for heat recovery) 53. The heat recovery section 53 recovers the compression heat generated during the pressure boosting process in the pressure booster 51 from the vaporized gas VG discharged from the pressure booster 51. Note that the gas vaporization system 5 is configured to effectively utilize the compression heat recovered by the heat recovery section 53 by supplying it to the liquefied gas LG, the heat medium HC, or the heat absorption section 15d.

[0071] When the pressure booster 51 is provided as in this embodiment, since most of the power supplied to the pressure booster 51 (generally 80 - 90%) is converted into compression heat during the pressure boosting process of the vaporized gas VG, it is preferable to provide the heat recovery section 53 that recovers the generated compression heat. Here, a specific example of the configuration for effectively utilizing the compression heat recovered by the heat recovery section 53 will be described with reference to FIGS. 10 and 11.

[0072] FIG. 10 schematically shows a configuration example when the above compression heat is supplied to the heat medium HC. The heat recovery section 53 in the example shown in FIG. 10 is configured such that the vaporized gas VG discharged from the pressure booster 51 flows through it, and the compression heat generated during the pressure boosting process in the pressure booster 51 is recovered by heat exchange with the heat medium HC. The heat recovery section 53 of this aspect uses, for example, a plate - type heat exchanger. While the vaporized gas VG discharged from the pressure booster 51 flows through the high - temperature side flow path, the heat medium HC in the heat medium tank 11 flows through the low - temperature side flow path.

[0073] Furthermore, in the example shown in FIG. 10, the gas vaporization system 5 has a fourth circulation path L4 configured to interpose the inside of the heat medium tank 11 and the heat recovery unit 53, and it is possible to circulate the heat medium HC in the fourth circulation path L4. The fourth circulation path L4 includes a fourth circulation forward pipe 61 that sends the heat medium HC heated by the heat recovery unit 53 to the heat medium tank 11, and a fourth circulation return pipe 62 that returns the heat medium HC after heat utilization in the heat medium tank 11 to the heat recovery unit 53. A fourth circulation pump 63 for circulating the heat medium HC in the fourth circulation path L4 is provided in the fourth circulation forward pipe 61.

[0074] With such a configuration, by partially heating the heat medium HC using the compression heat, the heat output of the heat pump circuit 15X is reduced. As a result, most of the power consumption of the booster 51 can be utilized as heat energy, and the power consumption of the entire system can be suppressed.

[0075] FIG. 11 schematically shows a configuration example when the compression heat is supplied to the heat absorption unit 15d. The heat recovery unit 53 in the example shown in FIG. 11 is configured such that the vaporized gas VG discharged from the booster 51 flows through it, and the compression heat generated during the pressure boosting process in the booster 51 is recovered by heat exchange with an intermediate medium MC (for example, warm water). The heat recovery unit 53 of this aspect uses, for example, a plate heat exchanger. While the vaporized gas VG discharged from the booster 51 flows through the high-temperature side flow path, the intermediate medium MC flows through the low-temperature side flow path. Also, in this example, the heat pump circuit 15X is a water heat source type heat pump circuit with the heat absorption unit 15d as a plate heat exchanger.

[0076] Furthermore, in the example shown in FIG. 11, the gas vaporization system 5 has a fifth circulation path L5 configured to interpose the heat absorption unit 15d and the heat recovery unit 53, and it is possible to circulate the intermediate medium MC in the fifth circulation path L5. The fifth circulation path L5 includes a fifth circulation forward pipe 64 that sends the intermediate medium MC heated by the heat recovery unit 53 to the heat absorption unit 15d, and a fifth circulation return pipe 65 that returns the intermediate medium MC after heat absorption in the heat absorption unit 15d to the heat recovery unit 53. A fifth circulation pump 66 for circulating the intermediate medium MC in the fifth circulation path L5 is provided in the fifth circulation forward pipe 64.

[0077] With such a configuration, by using the compression heat as the heat source of the heat pump circuit 15X, the COP (Coefficient of Performance) of the heat pump circuit 15X is improved. As a result, most of the power consumption of the booster 51 can be utilized as thermal energy, and the power consumption of the entire system can be suppressed.

[0078] 6. Regarding the use of the auxiliary heating device The gas vaporization systems 1 to 5 of the above-described embodiments each include the main heating device 15 as a device for heating the heat medium HC, but may be provided with an auxiliary heating device including a combustion type hot water boiler or an electric heater for backup heating. As a specific example of a gas vaporization system provided with such an auxiliary heating device, an example in which an auxiliary heating device is added to the gas vaporization system 1 of the first embodiment (gas vaporization system 6) will be described below.

[0079] FIG. 12 schematically shows the configuration of the gas vaporization system 6. As shown in this figure, the gas vaporization system 6 has an auxiliary heating device 71 for heating the heat medium HC, and a sixth circulation path L6 configured to interpose the inside of the heat medium tank 11 and the auxiliary heating device 71, and it is possible to circulate the heat medium HC in the sixth circulation path L6.

[0080] The sixth circulation path L6 includes a sixth circulation supply pipe 72 that sends the heat medium HC heated by the auxiliary heating device 71 to the heat medium tank 11, and a sixth circulation return pipe 73 that returns the heat medium HC after heat utilization in the heat medium tank 11 to the auxiliary heating device 71. A sixth circulation pump 74 for circulating the heat medium HC in the sixth circulation path L6 is provided in the sixth circulation supply pipe 72. When the auxiliary heating device 71 is a hot water boiler, it is preferable to connect the sixth circulation supply pipe 72 to the water inlet pipe of the hot water boiler and the sixth circulation return pipe 73 to the hot water outlet pipe of the hot water boiler. On the other hand, when the auxiliary heating device 71 is an electric heater, it is preferable to install a heating container with an electric heater disposed inside, and connect the sixth circulation supply pipe 72 and the sixth circulation return pipe 73 to this heating container.

[0081] Furthermore, the gas vaporization system 6 includes a sixth temperature detection unit (temperature sensor) 75 that detects the temperature of the heat source fluid HS supplied to the endothermic unit 15d, and a seventh temperature detection unit (thermostat temperature sensing unit) 76 that detects the temperature of the heat medium HC after heating by the auxiliary heating device 71. When the auxiliary heating device 71 is a hot water boiler, the seventh temperature detection unit 76 may be, for example, a thermostat temperature sensing unit provided in the hot water outlet pipe. On the other hand, when the auxiliary heating device 71 is an electric heater, the seventh temperature detection unit 76 may be, for example, a thermostat temperature sensing unit provided in the sixth circulation return pipe 72.

[0082] In the gas vaporization system 6, the controller 16 operates the auxiliary heating device 71 when the detected temperature of the sixth temperature detection unit 75 is lower than the set reference temperature. When the auxiliary heating device 71 is a hot water boiler, the combustion start and stop of the burner in the hot water boiler are switched using the ON / OFF signal of the thermostat. On the other hand, when the auxiliary heating device 71 is an electric heater, the power-on start and stop of the electric heater are switched using the ON / OFF signal of the thermostat.

[0083] Also, during the operation of the auxiliary heating device 71, the controller 16 controls the heat output of the auxiliary heating device 71 so that the detected temperature of the seventh temperature detection unit 76 becomes the set base temperature (the set temperature of the thermostat). This base temperature may be, for example, a temperature that is lower than the average temperature of the heat medium HC stored in the heat medium tank 11 by a predetermined temperature when the auxiliary heating device 71 is not required to operate (when only the main heating device 15 is operated, or when the heat recovered by the heat recovery unit 53 is used while the main heating device 17 is operated, and the heat medium HC can be heated to the required temperature). Thereby, it is possible to control the heat output of the auxiliary heating device 71 to an appropriate state without excess or deficiency.

[0084] Here, when the temperature of the heat source fluid HS is low, it becomes difficult for the heat pump circuit 15X to obtain the required heating amount. In particular, in the heat pump circuit 15X in the case of an air heat source type, in winter when the outside air temperature drops, the heating amount significantly decreases with the deterioration of the COP. Therefore, in the gas vaporization system 6, when the temperature of the heat source fluid HS falls below the reference temperature (for example, 5°C), the auxiliary heating device 71 is operated to perform backup heating. In this backup heating, the heat output of the auxiliary heating device 71 is adjusted so that the temperature of the stored heat medium HC becomes the base temperature. Thereby, it is possible to supplement the heating amount that is insufficient with only the main heating device 15.

[0085] Further, in the air heat source type heat pump circuit 15X, it may be necessary to perform a defrost operation in winter to remove the frost adhering to the heat transfer surface of the heat absorption part 15d. During this defrost operation, the heat pump circuit 15X cannot heat the heat medium HC, but by providing the auxiliary heating device 71, the heat medium HC can be heated to the required temperature (the required temperature when it can be heated only by the heat pump circuit 15X).

[0086] 7. Others The gas vaporization systems of the above-described embodiments each include a heat medium tank 11 that stores the heat medium HC, an evaporation unit 12 that is disposed inside the heat medium tank 11 and vaporizes the liquefied gas LG into the vaporized gas VG by heat exchange with the heat medium HC, an inflow pipe 13 that allows the liquefied gas LG to flow into the evaporation unit 12, an outflow pipe 14 that allows the vaporized gas VG to flow out from the evaporation unit 12, a main heating device 15 (configured to include a vapor compression type heat pump circuit 15X having a compressor 15a, a heat radiation part 15b, an expansion part 15c, and a heat absorption part 15d, and heating the heat medium HC by the heat output from the heat radiation part 15b), and a controller 16 that controls the heat output of the main heating device 15. Further, the controller 16 controls the heating amount of the heat medium HC based on the detection result of a state quantity having a correlation with the pressure of the vaporized gas VG in the vaporized gas VG or the heat medium HC.

[0087] As described above, since the gas vaporization system of each embodiment employs the vapor compression heat pump circuit 15X as the main heating device 15, the carbon dioxide emissions and energy costs can be reduced compared to the case where an electric heater or a combustion boiler is used as the main heating device. Furthermore, the gas vaporization system of each embodiment includes a controller 16 that controls the heating amount of the heat medium HC based on the detection result of a state quantity that has a correlation with the pressure of the vaporized gas VG in the vaporized gas VG or the heat medium HC. According to the control of the heat output of the main heating device 15 by the controller 16, it is possible to maintain the pressure of the vaporized gas VG flowing through the outflow pipe 14 within a predetermined range. Therefore, even while using a heat pump, it is possible to stabilize the supply pressure of the vaporized gas VG to a supply destination such as a gas-using device.

[0088] As described above, the embodiments of the present invention have been explained. However, the configuration of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. That is, the above embodiments should be considered as illustrative in all respects and not restrictive. The technical scope of the present invention is indicated by the scope of claims rather than the description of the above embodiments, and it should be understood that all modifications belonging to the meaning and scope equivalent to the scope of claims are included.

Explanation of Reference Numerals

[0089] 1 - 6 Gas vaporization system 11 Heat medium tank 12 Evaporation section 12a Evaporation pipe 12b Evaporation cylinder 13 Inflow pipe 14 Outflow pipe 15 Main heating device 15X Heat pump circuit 15a Compressor 15b Heat dissipation section 15b1 First heat dissipation section 15b2 Second heat dissipation section 15c Expansion section 15d Heat absorption section 16 Controller 17 Pressure adjustment unit 18 Capillary tube 18a Drain valve 19a First pressure detection unit 19b First temperature detection unit 19c Second temperature detection unit 19d Third temperature detection unit 19e Fourth temperature detection unit 21 First circulation supply pipe 22 First circulation return pipe 23 First circulation pump 31 Heat exchange unit 32 Second circulation supply pipe 33 Second circulation return pipe 34 Second circulation pump 35 Third circulation supply pipe 36 Third circulation return pipe 37 Third circulation pump 41 First branch pipe 42 Second branch pipe 43 Gas flow rate adjustment unit 44 Second pressure detection unit 45 Fifth temperature detection unit 51 Booster 52 Capacity control valve 53 Heat recovery unit 61 Fourth circulation supply pipe 62 Fourth circulation return pipe 63 Fourth circulation pump 64 Fifth circulation supply pipe 65 Fifth circulation return pipe 66 Fifth circulation pump 71 Auxiliary heating device 72 Sixth circulation supply pipe 73 Sixth circulation return pipe 74 Sixth circulation pump 75 Sixth temperature detection unit 76 Seventh temperature detection unit L1 First circulation path L2 Second circulation path L3 Third circulation path L4 Fourth circulation path L5 Fifth circulation path L6 Sixth circulation path LG Liquefied gas VG Vaporized gas R Refrigerant HC Heat medium HS Heat source fluid MC Intermediate medium

Claims

1. A heat medium tank for storing a heat medium, An evaporation section disposed inside the heat medium tank, which vaporizes a liquefied gas into a vaporized gas by heat exchange with the heat medium, An inflow pipe for allowing the liquefied gas to flow into the evaporation section, An outflow pipe for allowing the vaporized gas to flow out from the evaporation section, A main heating device configured to include a vapor compression type heat pump circuit having a compressor, a heat dissipation section, an expansion section, and a heat absorption section, and heating the heat medium by heat output from the heat dissipation section, A controller for controlling the heat output of the main heating device, The controller, A gas vaporization system that controls the heating amount of the heat medium based on a detection result of a state quantity having a correlation with the pressure of the vaporized gas in the vaporized gas or the heat medium.

2. Comprising a first pressure detection section for detecting the pressure of the vaporized gas flowing through the outflow pipe, The controller controls the heat output of the main heating device such that the detected pressure of the first pressure detection section becomes a set target pressure. The gas vaporization system according to claim 1.

3. Comprising a first temperature detection section for detecting the temperature of the vaporized gas flowing through the outflow pipe, The controller controls the heat output of the main heating device such that the detected temperature of the first temperature detection section becomes a set target temperature. The gas vaporization system according to claim 1.

4. Comprising a second temperature detection section for detecting the temperature of the heat medium existing in the vicinity of the evaporation section, The controller controls the heat output of the main heating device such that the detected temperature of the second temperature detection section becomes a set second target temperature. The gas vaporization system according to claim 1.

5. A third temperature detection section for detecting the temperature of the heat medium before heating in the heat dissipation section, A fourth temperature detection section for detecting the temperature of the heat medium after heating in the heat dissipation section, The controller controls the heat output of the main heating device such that the detected temperature difference between the fourth temperature detection section and the third temperature detection section becomes a set target temperature difference. The gas vaporization system according to claim 1.

6. The heat dissipation section is disposed inside the heat medium tank in a state capable of heat exchange with the heat medium, The controller controls the heat output of the main heating device by adjusting the rotation speed of the compressor. The gas vaporization system according to any one of claims 2 to 5.

7. The main heating device, A first circulation forward path pipe for sending the heat medium after heating in the heat dissipation section to the heat medium tank, A first circulation return pipe for returning the heat medium after heat utilization in the heat medium tank to the heat dissipation part; A first circulation pump provided in the first circulation forward pipe, and includes: The controller is configured to: Drive the first circulation pump at a predetermined rotation speed and adjust the rotation speed of the compressor to control the heat output of the main heating device. The gas vaporization system according to any one of claims 2 to 5.

8. The main heating device includes: A heat exchange part for heat-exchanging the heat medium and the intermediate medium; A second circulation forward pipe for sending the intermediate medium after being heated in the heat dissipation part to the high-temperature side of the heat exchange part; A second circulation return pipe for returning the intermediate medium after heat utilization on the high-temperature side of the heat exchange part to the heat dissipation part; A second circulation pump provided in the second circulation forward pipe; A third circulation forward pipe for sending the heat medium after being heated on the low-temperature side of the heat exchange part to the heat medium tank; A third circulation return pipe for returning the heat medium after heat utilization in the heat medium tank to the low-temperature side of the heat exchange part; A third circulation pump provided in the third circulation forward pipe, and includes: The controller is configured to: Drive the second circulation pump and the third circulation pump at a predetermined rotation speed and adjust the rotation speed of the compressor to control the heat output of the main heating device. The gas vaporization system according to any one of claims 2 to 5.

9. The main heating device includes: The heat dissipation part includes a first heat dissipation part in the front stage and a second heat dissipation part in the rear stage, and is configured to heat the heat medium by the heat output from the first heat dissipation part and heat the liquefied gas by the heat output from the second heat dissipation part; A first branch pipe for sending the liquefied gas flowing through the upstream side of the inflow pipe to the second heat dissipation part; A second branch pipe for returning the liquefied gas preheated in the second heat dissipation part to the downstream side of the inflow pipe; A gas flow rate adjustment part for adjusting the flow rate of the liquefied gas sent from the inflow pipe to the first branch pipe; A second pressure detection part for detecting the pressure of the liquefied gas before flowing into the evaporation part; A fifth temperature detection part for detecting the temperature of the liquefied gas before flowing into the evaporation part, and includes: The controller is configured to: Obtain the saturation temperature of the liquefied gas at the detected pressure of the second pressure detection part, and control the gas flow rate adjustment part so that the detected temperature of the fifth temperature detection part is lower than the saturation temperature. The gas vaporization system according to any one of claims 2 to 5.

10. A booster for boosting the pressure of the vaporized gas flowing through the outflow pipe; A capacity control valve provided on the suction side of the booster to adjust the suction pressure. The controller The gas vaporization system according to claim 2, wherein the controller controls the opening degree of the capacity control valve so that the internal pressure of the evaporation unit becomes a pressure lower than the target pressure.

11. Recover the compression heat generated during the pressure boosting process in the booster from the vaporized gas discharged from the booster. The gas vaporization system according to claim 10, wherein the recovered compression heat is supplied to the liquefied gas, the heat medium, or the heat absorption unit.

12. A heat recovery unit through which the vaporized gas discharged from the booster flows, and the compression heat generated during the pressure boosting process in the booster is recovered by heat exchange with the heat medium. A fourth circulation supply pipe that sends the heat medium heated in the heat recovery unit to the heat medium tank. A fourth circulation return pipe that returns the heat medium after heat utilization in the heat medium tank to the heat recovery unit. The gas vaporization system according to claim 10, further comprising a fourth circulation pump provided in the fourth circulation supply pipe.

13. A heat recovery unit through which the vaporized gas discharged from the booster flows, and the compression heat generated during the pressure boosting process in the booster is recovered by heat exchange with an intermediate medium. A fifth circulation supply pipe that sends the intermediate medium heated in the heat recovery unit to the heat absorption unit. A fifth circulation return pipe that returns the intermediate medium after heat absorption in the heat absorption unit to the heat recovery unit. The gas vaporization system according to claim 10, further comprising a fifth circulation pump provided in the fifth circulation supply pipe.

14. An auxiliary heating device for heating the heat medium. A sixth circulation supply pipe that sends the heat medium heated by the auxiliary heating device to the heat medium tank. A sixth circulation return pipe that returns the heat medium after heat utilization in the heat medium tank to the auxiliary heating device. A sixth circulation pump provided in the sixth circulation supply pipe. A sixth temperature detection unit that detects the temperature of the heat source fluid supplied to the heat absorption unit. A seventh temperature detection unit that detects the temperature of the heat medium after being heated by the auxiliary heating device. The auxiliary heating device is configured to include a combustion type hot water boiler or an electric heater. The controller operates the auxiliary heating device when the detected temperature of the sixth temperature detection unit is lower than a set reference temperature. During the operation of the auxiliary heating device, the heat output of the auxiliary heating device is controlled so that the detected temperature of the seventh temperature detection unit becomes a set base temperature. The gas vaporization system according to any one of claims 2 to 5.

Images