JP2010096275A - Liquefied gas supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquefied gas supply device capable of controlling pressure in a container housing liquefied gas so that the pressure in the container reaches pressure corresponding to an outside air temperature. <P>SOLUTION: The liquefied gas supply device includes: the container 3 housing the liquefied gas; a liquefied gas heating means 13 for heating the liquefied gas in the container; a pressure detecting means 11 for detecting the pressure of a gas phase in the container; an outside air temperature detecting means 21 for detecting the outside air temperature at the periphery of the container; and a control section 23 for controlling the heating amount of the liquefied gas heating means based on a value of the pressure detected by the pressure detecting means and a value of the outside air temperature detected by the outside air temperature detecting means. The control section 23 controls the heating amount of the liquefied gas heating means according to deviation between the pressure detected by the pressure detecting means and a set pressure line previously set corresponding to the outside air temperature detected by the outside air temperature detecting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquefied gas supply device that heats a liquefied gas in a container containing liquefied gas, and more particularly to a technique for controlling the pressure in the container.

  As a facility for supplying liquefied gas, there is known a facility that utilizes natural vaporization that includes a container for storing liquefied gas and a gas pipe line communicating with a gas phase portion in the container. The liquid-phase liquefied gas accommodated in a container installed outdoors or indoors is vaporized by heat from outside air around the container. The gas phase liquefied gas in the container is supplied to equipment and devices that use the gas phase liquefied gas via a gas conduit communicating with the gas phase portion. In such facilities that supply liquefied gas, the amount of vaporization and the pressure in the container fluctuate due to heat from the outside air around the container, so that the gas pressure liquefied gas is supplied while maintaining the pressure above a predetermined pressure. Is difficult.

  Therefore, a container for storing the liquefied gas is provided with a heater for heating the liquefied gas stored in the container, and the pressure in the gas conduit through which the gas phase liquefied gas from the container flows or the container There has been proposed a liquefied gas supply device that controls heating of liquefied gas in a container by a heater in accordance with the ambient outside air temperature (see, for example, Patent Document 1).

  In such a liquefied gas supply device, a pressure switch for detecting the pressure in the container is provided in order to prevent the supply of the gas phase liquefied gas at the pressure required by the equipment and facilities using the liquefied gas. When the pressure in the container is equal to or lower than the pressure set in the pressure switch, the heater heats the liquefied gas in the container and raises the temperature in the container to increase the vaporization amount of the liquefied gas in the liquid phase. The pressure inside is raised. Further, when the outside air temperature detected by the outside air temperature detecting means becomes equal to or higher than a predetermined temperature, the heating of the liquefied gas by the heater is stopped. This outside air temperature is detected to determine whether or not to heat the liquefied gas, and in the case of heating, the heating is controlled by the pressure switch so that the pressure in the container falls within the set range.

  However, in the liquefied gas supply device of Patent Document 1, one or a plurality of fixed pressure values are set in advance in the pressure switch, and heating is started or stopped by the heater according to the set pressure value. Is called. Therefore, for example, in summer when the outside temperature is high, heating is started if the pressure in the container is temporarily lower than a set value even if the outside temperature is high, and this causes a problem that unnecessary energy is consumed. .

  On the other hand, the temperature sensitivity which has the 1st and 2nd pressure chamber separated on both sides of the partition (diaphragm) which moves with an internal pressure difference, and enclosed the liquefied gas accommodated in the container of a liquefied gas supply apparatus. Liquefied gas supply comprising a pressure switch that communicates with the first pressure chamber, communicates the gas phase portion in the container of the liquefied gas supply device with the second pressure chamber, and outputs a signal in accordance with the movement of the partition wall An apparatus is disclosed (see Patent Document 2).

  According to this, according to the differential pressure between the saturated vapor pressure of the liquefied gas corresponding to the ambient temperature around the container detected by the temperature sensing unit and the saturated vapor pressure of the liquefied gas in the container corresponding to the temperature in the container. By moving the partition wall, the pressure switch is turned on / off, and heating and stopping of the heater of the liquefied gas supply device are controlled. Here, the set pressure value for outputting a signal for controlling heating and stopping of the container by the heater when the pressure switch is turned on and off rises and falls according to the rise and fall of the outside air temperature. Thereby, the temperature difference between the temperature in the container and the temperature around the container can be reduced, and the heat radiation from the container to the outside air can be reduced, so that energy saving can be improved.

JP 2003-185094 A Japanese Patent Application Laid-Open No. 2005-233231

  However, when the pressure switch as in Patent Document 2 is used, the following problems may occur. That is, since the diaphragm is usually made of rubber, it needs to be replaced periodically as it deteriorates with time, and the rubber permeates gas somewhat, so that the gas enclosed in the temperature sensitive part may be lost. In addition, since the saturated vapor pressure of the liquefied gas is led to the first and second pressure chambers, respectively, for example, when the temperature of the first and second pressure chambers decreases, the gas phase liquefied gas in these pressure chambers May re-liquefy and deteriorate the rubber of the diaphragm, and the detected pressure may become unstable.

  Further, according to Patent Document 2, the set pressure value of the pressure switch that outputs a signal for controlling heating and stopping of the container by the heater rises and falls according to the rise and fall of the outside air temperature. For example, the outside air temperature is high. In summer, the set pressure value cannot be lowered to suppress unnecessary heating. Conversely, in winter, when the outside air temperature is low, the set pressure value cannot be set high to maintain the supply pressure of liquefied gas. There is a problem.

  This invention makes it a subject to control the pressure in a container so that the pressure in the container in which the liquefied gas was accommodated will become a pressure corresponding to external temperature.

  In order to solve the above problems, the liquefied gas supply apparatus of the present invention detects a pressure in a container in which the liquefied gas is stored, a liquefied gas heating means for heating the liquefied gas in the container, and a gas phase portion in the container. Of the liquefied gas heating means based on the pressure value detected by the pressure detection means and the outside air temperature detected by the outside temperature detection means. A control unit for controlling the heating amount, and the control unit according to a deviation between the pressure detected by the pressure detecting unit and a preset pressure line corresponding to the outside temperature detected by the outside temperature detecting unit. The heating amount of the liquefied gas heating means is controlled.

  According to such a configuration, the pressure in the container can be controlled based on a preset pressure line set in advance according to the outside air temperature. For example, a set pressure line is set for each of a plurality of temperature regions of the outside air temperature. This makes it possible to control the pressure according to the season. Here, the control unit appropriately controls the heating amount of the liquefied gas heating unit so that the pressure detected by the pressure detection unit approaches the pressure value on the set pressure line at the outside air temperature.

  In this case, when the outside temperature detected by the outside temperature detecting means is equal to or higher than the first outdoor temperature, the set pressure line is set to a pressure smaller than the saturated vapor pressure at the outside temperature of the liquefied gas. According to this, for example, when the set pressure line is set along the saturated vapor pressure curve of the liquefied gas, the liquefied gas is heated until the temperature in the container reaches the same temperature as the outside air temperature, whereas the outdoor temperature is In summer, when the temperature is higher than the first outdoor temperature, the heating of the liquefied gas is stopped before the temperature inside the container reaches the high outside air temperature. Can be realized.

  Further, when the outside air temperature detected by the outside air temperature detecting means is equal to or lower than the second outdoor temperature which is smaller than the first outdoor temperature, the set pressure line is set to a pressure larger than the saturated vapor pressure at the outside temperature of the liquefied gas. Shall. According to this, in the winter season when the outdoor temperature is equal to or lower than the second outdoor temperature, the liquefied gas is heated until the pressure in the container becomes higher than the saturated vapor pressure at the low outdoor temperature. The pressure required to supply the gas can be ensured.

  More specifically, the liquefied gas heating means includes a flow path provided on the outer wall of the container, and a heat medium heating means for circulating the heat medium in the flow path and heating the heat medium, The operation of the heating medium heating means is controlled based on the pressure value detected by the pressure detecting means and the outside air temperature value detected by the outside air temperature detecting means. The pressure detected by the pressure detecting means is the outside air temperature detection. If the first set pressure line preset in correspondence with the outside air temperature detected by the means is exceeded, the operation of the heating medium heating means is stopped, and less than the second set pressure line smaller than the first set pressure. Then, the operation of the heat medium heating means is started.

  By the way, in cold districts and the like, since the peak of gas consumption occurs in the morning of winter, it is required to maintain a predetermined supply pressure and maintain stable supply even in such a case. Therefore, in the present invention, when an external signal that can change the first set pressure line and the second set pressure line is input to the control unit, the first set pressure line and the second set pressure line are set. The pressure is changed to the specified pressure line.

  According to this, at the site where the liquefied gas supply device is installed, by performing a predetermined operation as necessary, for example, the first set pressure line and the second set pressure line are set by a preprogrammed pressure amount. Since it can be shifted to the high pressure side, a predetermined supply pressure can be maintained even if the gas supply amount increases. Here, the means for outputting an external signal that can change the set pressure line is not particularly limited, but, for example, one that can be easily operated on site by equipment provided in the liquefied gas supply device is preferable. Further, the change amount of the set pressure line may be fixed in advance or may be adjusted as necessary.

  In addition, provided with an informing means for receiving and notifying an abnormal signal from the control unit, the control unit, when the pressure detected by the pressure detection unit is equal to or less than a third set pressure line smaller than the second set pressure line, You may comprise so that an abnormal signal may be output to a control part. According to this, since the set pressure value for detecting the abnormality can be set according to the outside air temperature instead of the fixed point or points, if an abnormal pressure drop occurs earlier, Abnormalities can be detected. Therefore, it is possible to earn a longer time to repair the failure, and to prevent the supply of liquefied gas from being stopped due to the pressure drop.

  According to the present invention, the pressure in the container can be controlled so that the pressure in the container in which the liquefied gas is accommodated is a pressure corresponding to the outside air temperature.

(First embodiment)
Hereinafter, a first embodiment of a liquefied gas supply apparatus to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a diagram for explaining the schematic configuration and operation of a liquefied gas supply apparatus to which the present invention is applied. FIG. 2 is a diagram for explaining the relationship between the outside air temperature and the set pressure line in the container in the pressure control of the liquefied gas supply apparatus to which the present invention is applied. In the present embodiment, the configuration in the case where gas-phase liquefied gas is supplied from a container containing liquefied gas to a predetermined device or apparatus will be described, but the supply device or apparatus is particularly limited. It is not a thing.

  As shown in FIG. 1, the liquefied gas supply device 1 of this embodiment communicates with a container 3 for storing and storing a liquefied gas, for example, liquefied petroleum gas (LPG), and a gas phase section 5 in the container 3. Gas pipe 7 to be operated, two regulating valves 9a and 9b for adjusting the gas supply pressure, a pressure sensor 11 for detecting the pressure in the container 3, and a heater which is installed at the bottom of the container 3 and serves as a liquefied gas heating means 13, a temperature switch 15 for detecting the heating temperature of the heater 13, a heat source unit 17 serving as a heating medium heating unit, and a heating medium conduit for circulating a heating medium such as water between the heating unit 13 and the heating source unit 17. 19a, 19b, an outside air temperature sensor 21 that detects the outside air temperature around the container 3, and a control unit 23 that controls the operation of the liquefied gas supply device 1.

  The container 3 is supported on a leg portion (not shown) in a state where a substantially cylindrical container is turned sideways. Such a container 3 is installed outdoors, for example, and the liquid phase liquefied gas which becomes the liquid phase part 25 accommodated inside the container 3 is vaporized by the heat received by the container 3 from the outside air. For this reason, the vapor phase liquefied gas is accumulated in the vapor phase portion 5 at the upper portion of the container 3. In FIG. 1, the container 3 is shown in cross section. One end of the gas pipe line 7 communicates with the upper portion of the container 3, and the other end communicates with a supply destination of the gas phase liquefied gas.

  The pressure sensor 11 always detects the pressure of the gas phase part 5 in the container 3. The result detected by the pressure sensor 11 is always input as an electrical signal to the control unit 23 electrically connected to the pressure sensor 11. As the pressure sensor 11, for example, a known semiconductor sensor that outputs a voltage using a metal diaphragm and a pressure sensitive element can be used. The outside air temperature sensor 21 always detects the outside air temperature around the container 2. The result detected by the outside air temperature sensor 21 is always input as an electric signal to the control unit 23 electrically connected to the outside air temperature sensor 21. As the outside air temperature sensor 21, for example, a sensor using an element such as a thermistor whose resistance value changes in accordance with the temperature can be used.

  For example, the heater 13 is provided with a heat exchange pipe formed of a material having high thermal conductivity such as copper bent in a bellows shape in a metal case having an open upper surface. The space between the case and the case is filled with a heat transfer medium such as water or a heat transfer medium such as silicon. The edge of the upper surface of the case of such a heater 13 is attached in close contact with the bottom surface of the container 3. The temperature switch 15 is arranged so as to detect the temperature of the filling in the case of the heater 13, that is, the temperature of the heat transmitted to the container 3. The temperature switch 15 outputs a signal corresponding to each of two preset temperatures, for example, and outputs the output result to the control unit 23 as an electrical signal.

  The heat source unit 17 controls a flow path through which a heat medium (not shown) flows, a heat medium tank provided in the flow path, a pump, a burner for heating the heat medium in the flow path, and operations of the pump and the burner. The control part etc. which are integrated in the housing | casing are utilized, and a commercially available domestic water heater or hot water heater is used. The heat source device 17 of this embodiment is connected to a household power source of, for example, 100V, and the control unit of the heat source device 17 operates in cooperation with the control unit 23 and is electrically connected to the control unit 23. Has been.

  One end of the heat medium pipe line 19a is connected to a flow path through which a heat medium (not shown) of the heat source unit 17 flows, and the other end is connected to a pipe line formed in a bellows shape (not shown) of the heater 13. The heat medium heated by the heat source unit 17 flows through the heat medium pipe line 19a. The heat medium pipe 19b has one end connected to a pipe formed in a bellows shape (not shown) of the heater 13 and the other end connected to a flow path through which a heat medium (not shown) of the heat source unit 17 flows. The heat medium that has released heat by the heater 13 flows through the heat medium pipe line 19b.

  The controller 23 drives and stops the heat source device 17 according to the input result of the pressure value detected by the pressure sensor 11 and the outside air temperature value detected by the outside air temperature sensor 21, that is, a pump (not shown) of the heat source device 17 A circuit for starting and stopping the burner and heating and stopping the container 3 by the heater 13 and a circuit for driving and stopping the heat source device 17 in response to a signal from the temperature switch 15 are included. The control unit 23 controls the driving and stopping of the heat source unit 17 according to the input result of the detection signal of the pressure value from the pressure sensor 11 and the detection signal of the outside air temperature from the outside air temperature sensor 21. The heating and stopping in the container 3 are controlled so that the heater 13 does not heat the inside of the container 3 at a temperature higher than 40 ° C. which is a temperature stipulated by laws and regulations, for example, according to a detection signal from the temperature switch 15. The drive and stop of the heat source unit 17 are controlled. In addition, by arranging a valve (not shown) in at least one of the heat medium pipes 19a and 19b and controlling the valve opening degree according to a command from the control unit 23, the heat medium circulation amount can be controlled.

  Next, the operation of the liquefied gas supply apparatus configured as described above will be described.

  In this embodiment, when the detection signal of the pressure value from the pressure sensor 11 and the detection signal of the outside air temperature from the outside air temperature sensor 21 are input to the control unit 23, the control unit 23 previously stores the detection signal as shown in FIG. Based on the two set pressure lines A and B, two set pressure values corresponding to the outside air temperature are determined. Then, the heat source device 17 is driven and stopped, that is, a signal for circulating the heated heat medium to the heater 13 is started and stopped so that the pressure in the container 3 falls within the range of two set pressure values.

  As shown in FIG. 2, for example, when the detected value of the outside air temperature sensor 21 is 20 ° C. and no gas is supplied from the container 3, the detected pressure value of the pressure sensor 11 is the vapor pressure curve C ( 0.63 MPa corresponding to the set pressure line A). Thereafter, when the supply of the liquefied gas is started from the container 3 via the gas pipe line 7, the pressure detection value starts to decrease, and when the pressure falls below 0.59 MPa on the set pressure line B, the control unit 23 controls the heat source unit 17. A signal to start driving is transmitted to the heat source unit 17. When the drive start signal from the control unit 23 is input, the heat source unit 17 drives the pump to circulate the heat medium and starts combustion of the burner. Thereby, the heat medium heated through the heat medium pipe line 19 b is supplied to the heater 13.

  When the liquid phase portion 25 of the liquefied gas is heated by the heater 13, the vaporized amount of the liquefied gas increases in the container 3 and the pressure in the container 3 is increased. Thus, when the pressure detection value starts to increase and exceeds 0.63 MPa, the control unit 23 transmits a signal to the heat source unit 17 to stop driving the heat source unit 17.

  As described above, when the detected pressure detected by the pressure sensor 11 exceeds the set pressure value corresponding to the outside air temperature of the set pressure line A, the control unit 23 transmits a signal for stopping the driving of the heat source unit 17 and the detected pressure is When the pressure is less than the set pressure value corresponding to the outside air temperature of the set pressure line B, control is performed so that a signal for starting the driving of the heat source unit 17 is transmitted. Here, as shown in FIG. 2, since the set pressure line A is on the vapor pressure curve C of the liquefied gas when the outside air temperature is in the range of 5 ° C. or more and 27 ° C. or less, for example, this temperature range (hereinafter referred to as the intermediate temperature). In the term), since the liquefied gas is not heated above the outside air temperature, heat radiation from the inside of the container 3 to the outside of the container is suppressed, and energy saving can be realized.

  By the way, when the outside air temperature rises, the pressure in the container 3 rises following the vapor pressure curve C of the liquefied gas, but the supply pressure for supplying the gas phase liquefied gas in the container 3 to the supply destination is, for example, 0. About 0.8 MPa is sufficient. Therefore, as shown in FIG. 2, when the outside air temperature exceeds, for example, 27 ° C. (hereinafter referred to as the high temperature period), for example, the pressure in the container 3 does not exceed the saturated vapor pressure of 27 ° C. of the liquefied gas. The set pressure line A is set to a saturated vapor pressure value of 27 ° C. That is, the set pressure line A in the high temperature period is always lower than the vapor pressure curve C of the liquefied gas. The set pressure line B is set so as to have the same differential pressure as the set pressure lines A and B in the middle temperature period.

  In this way, since the saturated vapor pressure of the liquefied gas at 27 ° C. is slightly lower than 0.8 MPa, the liquefaction in the container 3 can be obtained by setting this pressure value as the set pressure line A, that is, the upper limit pressure. It is possible to control the gas not to be heated to 27 ° C. or higher. Therefore, in the high temperature period, the liquefied gas is not heated more than necessary, so that energy saving can be realized.

  On the other hand, when the outside air temperature becomes low, the pressure in the container 3 drops following the vapor pressure curve C of the liquefied gas. However, if this pressure is too low, there is a possibility that the supply pressure becomes insufficient and the stable supply may be hindered. The pressure in the container needs to be maintained at 0.4 MPa or more, for example. Therefore, when the outside air temperature falls below, for example, 5 ° C. (hereinafter referred to as the low temperature period), as shown in FIG. 2, the pressure in the container 3 is set with the saturated vapor pressure of liquefied gas at 5 ° C. as a guide. Line A is set to a saturated vapor pressure value of 5 ° C. That is, the set pressure line A in the low temperature period is always higher than the vapor pressure curve C of the liquefied gas. The set pressure line B is set so as to have the same differential pressure as the set pressure lines A and B in the middle temperature period.

  In this case, since the saturated vapor pressure of the liquefied gas at 5 ° C. is about 0.4 MPa, this pressure value is set to the set pressure line A, and the pressure in the container is set to 0.4 MPa as a guideline. Control of heating the gas can be performed. Therefore, in the low temperature period, the pressure in the container 3 does not drop following the vapor pressure curve C, and stable gas supply is possible even in the winter season when the amount of gas used is the largest.

  In the liquefied gas supply apparatus of the present embodiment, the outside air temperature is divided into three temperature ranges, a low temperature period, a medium temperature period, and a high temperature period, and set pressure lines A and B are set in consideration of the use situation and energy saving in each temperature range. is doing. Then, according to the deviation between the detected pressure detected by the pressure sensor 11 and the set pressure values on the set pressure lines A and B corresponding to the detected temperature of the outside air temperature sensor 21, the controller 23 drives the heat source unit 17 and A signal for controlling stop is output. Therefore, in the low temperature period, the pressure inside the container can be controlled with a pressure higher than the saturated vapor pressure of the liquefied gas as a guideline, so that the gas supply stability in winter can be improved, and in the middle temperature period, the liquefied gas saturation is improved. Since the pressure inside the container can be controlled using the vapor pressure as a guideline, heat dissipation from the inside of the container can be suppressed to improve energy savings. In the high temperature period, a pressure lower than the saturated vapor pressure of the liquefied gas can be used as a guide. Since the pressure inside the container can be controlled, unnecessary heating of the liquefied gas in the summer can be suppressed, and energy saving can be improved. In addition, although the pressure difference (differential) of the setting pressure line A and the setting pressure line B can be set to a desired value, it is preferable to set it as 0.05 MPa-0.1 MPa, for example.

  In the present embodiment, the outside air temperature is divided into three temperature ranges, and different pressure control is performed in each temperature range. This improves energy saving in the summer and gas supply pressure in the winter. This is because it is most efficient to set the set pressure line for each of the three temperature ranges, and the control becomes simple. Therefore, depending on the purpose such as pressure control, the way of dividing the temperature region differs. Incidentally, if the set pressure line in the high temperature period is too low, condensation will occur on the surface of the container 3 and the appearance will deteriorate, and the container 3 and piping will be easily rusted. In consideration of this, a set pressure line for the high temperature period is set. In addition, if the pressure in the container is kept at a certain level in the low temperature period, even if an abnormality such as a power failure occurs, the gas supply time becomes longer due to natural vaporization, and the gas supply stop can be suppressed. In the present embodiment, the set pressure value in the low temperature period is determined in consideration of such points.

  By the way, the mechanical structure used conventionally, that is, the pressure chamber communicating with the temperature sensing part enclosing the liquefied gas stored in the container of the liquefied gas supply device, and the communication with the inside of the container of the liquefied gas supply device are communicated. In a liquefied gas supply device using a pressure switch having a structure in which the pressure chambers are separated from each other by a diaphragm and a signal is output in accordance with the movement of the diaphragm, the burden of maintenance due to the mechanical structure becomes a problem. . In addition, in the pressure control in the container using such a pressure switch, the pressure in the container is controlled so as to change along the vapor pressure curve of the liquefied gas, so that the pressure suitable for the season such as summer or winter Control cannot be performed.

  On the other hand, in the liquefied gas supply apparatus of this embodiment, the pressure in the container is controlled so as to be lower than the vapor pressure of the liquefied gas in the summer, and energy is saved, and the vapor of the liquefied gas is used in the winter. Since the supply pressure can be ensured by controlling the pressure to be higher than the pressure, it is possible to perform pressure control suitable for the season such as summer or winter.

(Second Embodiment)
Hereinafter, a second embodiment of a liquefied gas supply apparatus to which the present invention is applied will be described with reference to the drawings. FIG. 3 is a perspective view showing a state in which a control panel and a lid of the control panel are opened in the control unit of the liquefied gas supply apparatus to which the present invention is applied. FIG. 4 is a diagram showing a state in which the first set pressure line A and the second set pressure line B are changed in the pressure control of the liquefied gas supply apparatus to which the invention is applied. In the present embodiment, the same components and operations as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only configurations and features that are different from those in the first embodiment will be described.

  The liquefied gasifier of this embodiment is different from the first embodiment in that the controller 23 changes the volume of the first set pressure line A and the second set pressure line B that are set in advance. It is in having. That is, the liquefied gas supply apparatus of the present embodiment has a control change volume 35 in addition to the operation lamp 31 and the operation switch 33 on the surface of the control box that houses the control unit 23, as shown in FIG. I have. The operation lamp 31 is lit during operation to display the operation state, and the operation switch 33 is a switch for starting operation of the liquefied gasifier, and these are the same as those in the first embodiment. To do. On the other hand, the control change volume 35 is unique to the present embodiment, and is for changing the increment of the first set pressure line A and the second set pressure line B. The user can change the first set pressure line A and the second set pressure line B to the height of the desired pressure line at the same time by rotating the control change volume 35 in the direction of the arrow.

  When the surface of the control box 37 is opened, as shown in FIG. 3 (b), the inside of the control box 37 is dedicated to the pressure sensor 11, the temperature switch 15, the outside air temperature sensor 21, the heat source unit 17, and the like. A terminal block 39 is provided in a state of being electrically connected to the control unit 23, and a dedicated terminal block 41 for causing the control change volume 35 to function is provided in a state of being electrically connected to the control unit 23. FIG. 3B shows a state where the contacts of the terminal block 41 are short-circuited by wiring. Thus, by short-circuiting the terminal block 41 with the wiring 43, the user uses the control change volume 35 to change the first set pressure line A and the second set pressure line B within a predetermined range. It becomes possible.

  In the present embodiment, by adjusting the control change volume 35 by short-circuiting the terminal block 41, an external signal corresponding to a change in the resistance value of the volume is transmitted to the control unit 23. On the other hand, the controller 23 is programmed so that the amount of change between the first set pressure line A and the second set pressure line B is set in proportion to the information contained in the external signal, that is, the resistance value of the volume. Therefore, the user can freely adjust the amount of change between the first set pressure line A and the second set pressure line B. Thus, in the present embodiment, the control change volume 35 is used to change the amount of increase and decrease of the first set pressure line A and the second set pressure line B, but the control change volume 35 is not provided. The first set pressure line A and the second set pressure line B can be changed to a preset position only by short-circuiting the terminal block 41.

  FIG. 4 shows a state in which the first set pressure line A and the second set pressure line B are increased by 0.1 MPa with respect to all temperature regions. That is, 0.1 MPa, which is the pressure increase, is the same as the pressure difference between the first set pressure line A and the second set pressure line B. Therefore, after the first set pressure line A is changed, 3 and the first pressure line A after changing the second pressure line B. Thereby, when the pressure detection value of the pressure sensor 11 becomes a set pressure value on the third set pressure line D at the outside air temperature at a predetermined outside air temperature, the control unit 23 stops driving the heat source unit 17. Then, when the pressure detection value starts to decrease and reaches the set pressure value on the first set pressure line B at the outside air temperature, the control unit 23 sends a signal to start driving the heat source unit 17. To do.

  According to the present embodiment, the user can easily connect the first set pressure line A and the second set pressure line B to the high pressure side by short-circuiting the terminal block 41 at the site where the liquefied gas supply device is installed. Can be moved to. Thereby, for example, when a peak of gas usage occurs in the morning in winter, such as in a cold region, by increasing the pressure in the container 3 in advance, the gas supply pressure of the liquefied gas supply device is reduced to the required amount. It can be ensured, and the stable supply of gas can be improved. After exceeding the peak of gas usage, the terminal block 41 is opened again, and the volume of the first set pressure line A and the second set pressure line B is lowered to the original state, thereby liquefied gas. It is possible to eliminate excessive heating and improve energy saving.

  Further, according to the present embodiment, for example, even when equipment or devices that use liquefied gas is changed, an appropriate supply pressure is adjusted by adjusting the control pressure to be suitable for those equipment or devices. This can maintain the versatility of the liquefied gas supply device. In this embodiment, if a commercially available weekly timer or the like is connected between the contacts of the terminal block 41, the control pressure in the container 3 can be automatically changed for a required time.

  In the present embodiment, the first set pressure line A and the second set pressure line B are simultaneously changed by the same pressure amount. For example, the control change volume 35 corresponding to each set pressure line is used. Etc., the first set pressure line A and the second set pressure line B can be adjusted independently. In the present embodiment, the control change volume 35 is used to change the first set pressure line A and the second set pressure line B. Instead of this, for example, a preset value is set. Terminal blocks corresponding to a plurality of set pressure lines are respectively provided in the control box 37, and the terminal blocks corresponding to desired set pressure lines are short-circuited by the user, whereby the first set pressure lines A and the second set pressure lines are shorted. The set pressure line B may be changed.

(Third embodiment)
Hereinafter, a third embodiment of a liquefied gas supply apparatus to which the present invention is applied will be described with reference to the drawings. FIG. 5 is a diagram for explaining the relationship between the outside air temperature and the set pressure line in the container in the pressure control of the liquefied gas supply apparatus to which the present invention is applied. Note that in this embodiment, the same components and operations as those in the other embodiments are denoted by the same reference numerals, description thereof is omitted, and only configurations and features that are different from those in the other embodiments will be described.

  The difference between the liquefied gas supply device of this embodiment and the other embodiments is that an abnormality occurs when the detected pressure in the container 3 detected by the pressure sensor 11 is less than or equal to the abnormal pressure value set according to the outside air temperature. It is in having a means for notifying that. That is, in the liquefied gas supply apparatus of the present embodiment, when the detected pressure of the pressure sensor 11 is input to the control unit 23 and detected that the control unit 23 is equal to or lower than the abnormal pressure value set in advance, the control unit 23 A signal for sounding a buzzer is transmitted to a predetermined notification means electrically connected to the control unit 23.

  In the present embodiment, as shown in FIG. 5, when the pressure in the container 3 decreases and falls below the set pressure line E, the control unit 23 detects this and sends a notification signal to the notification means. Here, the set pressure line E is set to be smaller than the set pressure line B by a predetermined pressure for all temperature regions.

  Incidentally, in the conventional liquefied gas supply device, in order to detect an abnormal pressure drop in the container 3, it is necessary to provide a pressure switch for detecting an abnormality separately in addition to the pressure sensor 11 of the present embodiment. However, when an abnormal pressure drop is detected by such a pressure switch for abnormality detection, only one fixed pressure value can be set as a set pressure value for detecting the abnormality. For this reason, for example, when the set pressure value for abnormality detection is set to 0.2 MPa in accordance with the winter season when the outside air temperature is low, the pressure in the container does not drop to 0.2 MPa even when the detected pressure is high in summer. Since the system abnormality cannot be detected, there is a possibility that the action for the abnormality may be delayed. That is, if the system of the liquefied gas supply device is operating normally, the pressure in the container once lowered will rise again. For example, a signal for driving the heat source unit 17 may not be transmitted due to a failure of the control unit 23. If the heat medium is not heated due to a failure of the heat source unit 17 or more gas than usual is supplied to the supply destination, the pressure in the container 3 continues to drop, and if this state is left, The pressure in the container 3 disappears, and the gas supply stops.

  In contrast, in the present embodiment, when the pressure in the container 3 drops to the set pressure line E set according to the outside air temperature, a pressure abnormality is detected and notified. Here, the set pressure line E is set higher when the outside air temperature is higher than 27 ° C., for example, and lower when the outside air temperature is lower than 5 ° C., for example. In the intermediate period, the pressure is set between the high temperature period and the low temperature period. Therefore, as described above, since the differential pressure between the control pressure during normal operation and the set pressure for abnormality detection is small at any outside air temperature as compared with the conventional liquefied gas supply device, the pressure abnormality is accordingly increased. It can be detected early.

  Furthermore, in the present embodiment, since the occurrence of an abnormality is notified by a buzzer or the like, the user can investigate the cause of the system abnormality and take measures before the pressure in the container disappears. The time from when an abnormality is detected until the gas supply stops depends on the operating conditions such as the gas supply amount and the outside air temperature. Therefore, it is possible to prevent the gas supply from being stopped.

  Further, according to the present embodiment, unlike the conventional liquefied gas supply device, it is not necessary to separately add an abnormality detection pressure switch, so that the equipment cost can be reduced. If the pressure in the container 3 is at least about 0.1 MPa, normal gas consuming equipment can continue to operate. However, if the supply pressure decreases, the gas piping and the like freeze, and stable gas supply can be achieved. Otherwise, the gas piping is easily corroded, so the set pressure line E needs to be determined in consideration of these problems. In the present embodiment, an example in which a buzzer is used as a notification unit has been described. However, the present invention is not limited to this as long as it can notify a user of an abnormality.

It is a figure explaining the schematic structure and operation | movement of 1st Embodiment of the liquefied gas supply apparatus to which this invention is applied. It is a figure explaining the relationship between the outside temperature in a control part, and the setting pressure line in a container. It is a perspective view showing the state which opened the cover of the control board and control board in the control part of 2nd Embodiment of the liquefied gas supply apparatus to which this invention is applied. It is a figure explaining the relationship between the outside temperature in the control part of 2nd Embodiment of the liquefied gas supply apparatus formed by applying this invention, and the setting pressure line in a container. It is a figure explaining the relationship between the external temperature in the control part of 3rd Embodiment of the liquefied gas supply apparatus formed by applying this invention, and the setting pressure line in a container.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquefied gas supply apparatus 3 Container 5 Gas phase part 11 Pressure sensor 13 Heater 15 Temperature switch 17 Heat source machine 21 Outside temperature sensor 23 Control part 35 Control change volume 41 Terminal block

Claims (6)

A container for storing the liquefied gas; a liquefied gas heating means for heating the liquefied gas in the container; a pressure detecting means for detecting the pressure of the gas phase in the container; and detecting an outside air temperature around the container. An outside air temperature detecting means, and a control unit for controlling a heating amount of the liquefied gas heating means based on a pressure value detected by the pressure detecting means and an outside air temperature value detected by the outside air temperature detecting means,
The control unit is configured to change the pressure of the liquefied gas heating unit according to a deviation between the pressure detected by the pressure detection unit and a preset pressure line corresponding to the outside temperature detected by the outside temperature detection unit. A liquefied gas supply device that controls the amount of heating.   The set pressure line is set to a pressure smaller than a saturated vapor pressure at the outside temperature of the liquefied gas when the outside temperature detected by the outside temperature detecting means is equal to or higher than a first outdoor temperature. The liquefied gas supply device described.   When the outside air temperature detected by the outside air temperature detecting means is equal to or lower than a second outdoor temperature that is smaller than the first outdoor temperature, the set pressure line is a pressure larger than the saturated vapor pressure of the liquefied gas at the outside air temperature. The liquefied gas supply device according to claim 1, wherein the liquefied gas supply device is set. The liquefied gas heating means includes a flow path provided on the outer wall of the container, and a heat medium heating means for circulating the heat medium in the flow path and heating the heat medium,
The control unit controls the operation of the heating medium heating unit based on the pressure value detected by the pressure detection unit and the outside air temperature value detected by the outside air temperature detection unit,
When the pressure detected by the pressure detecting means exceeds a first set pressure line set in advance corresponding to the outside air temperature detected by the outside air temperature detecting means, the control unit operates the heating medium heating means. The liquefied gas supply device according to any one of claims 1 to 3, wherein the operation of the heating medium heating means is started when the temperature is less than a second set pressure line that is smaller than the first set pressure. .   The controller sets the first set pressure line and the second set pressure line when an external signal enabling the change of the first set pressure line and the second set pressure line is input. The liquefied gas supply device according to claim 4, wherein the liquefied gas supply device is changed up to the pressure line. Informing means for receiving and notifying an abnormal signal from the control unit,
The said control part outputs the said abnormal signal to the said control part, when the pressure detected by the said pressure detection means becomes below the 3rd setting pressure line smaller than a said 2nd setting pressure line. Or the liquefied gas supply apparatus of 5.

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