JP5511453B2 - Vapor collection device - Google Patents

Description

  The present invention relates to a vapor recovery device, and in particular, supplies vapor to an adsorption tank filled with an adsorbent, adsorbs the fuel component contained in the vapor with the adsorbent, and then desorbs the fuel component adsorbed on the adsorbent. The present invention relates to a vapor recovery device configured to return to a tank.

  In a fuel supply facility such as a gas station, a tank for unloading liquid fuel from each hatch of a tank truck is installed. This kind of tank is mainly buried underground, and the liquid fuel loaded on the tanker truck evaporates from the liquid fuel when unloading via the unloading hose using the height difference from the tanker truck. Vapor (oil vapor) is generated in the upper space in the tank.

  In addition, the tank of the gas station is connected to a vent pipe having a vent connected to the atmosphere at a high place, and when unloading, the liquid level rises and the vapor is released into the atmosphere. Yes.

  In recent years, environmental pollution in the atmosphere has become a problem. Therefore, even when unloading, the fuel component (hydrocarbon, which is a main component of petroleum: HC component) contained in the vapor in the tank is recovered and the vapor is in the atmosphere. There is a need to prevent contamination.

  As the vapor recovery device, for example, an adsorbent (for example, silica gel) that adsorbs fuel components contained in the vapor is adsorbed (a process of adsorbing vapor on the adsorbent is referred to as an adsorption process), and the vapor is in the atmosphere. Some are configured to prevent release and to desorb the fuel component adsorbed by the adsorbent (the process of removing vapor from the adsorbent is referred to as a desorption process) and return it to the tank (for example, a patent) Reference 1).

JP 2008-264733 A

  However, conventionally, by providing a dedicated vapor collection device for each tank for each tank, the oil liquid loaded in each of the plurality of hatches of the tank truck is unloaded from each tank. The discharged vapor is collected by each vapor collection device, and the fuel component desorbed from the adsorbent is returned to the unloaded tank. For this reason, it is necessary to provide a vapor recovery device for each tank, and it is necessary to secure a space for installing a plurality of vapor recovery devices in the site of the gas station. There was a problem to do.

  Further, when the fuel component desorbed from the adsorbent is returned to the unloaded tank, the volume of the upper space of the tank is small. It will rise greatly. For this reason, the fuel component desorbed from the adsorbent cannot be immediately recirculated, and recirculation is not performed after the oil liquid in the tank has been consumed to some extent and the volume of the upper space in the tank has increased to some extent. There was a problem that it should not be.

  In view of the above circumstances, an object of the present invention is to provide a vapor recovery apparatus that solves the above-described problems.

In order to solve the above problems, the present invention has the following means.
(1) The present invention includes a plurality of tanks in which liquid fuel is unloaded,
An adsorption tank filled with an adsorbent for adsorbing vapor evaporated from the liquid fuel;
A desorption path communicating the suction tank and the suction port of the vacuum pump;
A reflux path communicating the discharge port of the vacuum pump and the plurality of tanks;
An adsorption process is performed in which the vapor discharged from the tank during unloading is supplied into the adsorption tank and the fuel component contained in the vapor is adsorbed by the adsorbent, and the fuel component contained in the vapor is adsorbed. Control means for performing a desorption step of desorbing the fuel component from the adsorbent after being adsorbed in a tank, and controlling the desorbed fuel component to be recirculated to the plurality of tanks via the recirculation path; A vapor recovery device comprising:
Wherein, when performing the desorption step, the desorbing fuel components adsorbed vapor to the adsorbent before Symbol in the adsorption vessel through the desorption path by activating the vacuum pump, which is said desorbing The fuel component is returned to another tank that is not unloaded among the plurality of tanks.
(2) In the present invention, a reflux on-off valve is provided in each of the branch paths of the reflux path communicating with the plurality of tanks,
The control means selectively opens the plurality of on-off valves so as to return the desorbed fuel component to another tank that is not unloaded among the plurality of tanks.

According to the present invention, when performing the desorption process, the vacuum pump is activated to desorb the vapor fuel component adsorbed by the adsorbent in the adsorption tank via the desorption path, and a plurality of desorbed fuel components are removed. By returning to another tank that was not unloaded , the fuel component that was desorbed to the unloaded tank was not recirculated, and the increase in the pressure in the tank that was just unloaded was recirculated. It is possible to prevent the breather valve of the vent pipe from opening due to the fuel component, and to prevent the vapor in the tank from being released into the atmosphere. Therefore, environmental pollution at the time of unloading can be prevented, and the installation space and equipment cost of the adsorption tank can be reduced.

It is a system configuration figure showing one example of the vapor recovery device by the present invention. It is a flowchart for demonstrating the vapor | steam collection | recovery control processing which a control apparatus performs. 3 is a flowchart for explaining a control process of a standby process 1; It is a flowchart for demonstrating the control process of an adsorption | suction process. It is a flowchart for demonstrating the control process performed following the control process of FIG. 4A. 5 is a flowchart for explaining a control process of a standby process 2. It is a flowchart for demonstrating the control processing of a desorption process. It is a flowchart for demonstrating a desorption interruption process. It is a flowchart for demonstrating a purge desorption process. It is a system block diagram which shows the modification of a vapor collection | recovery apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a system configuration diagram showing an embodiment of a vapor recovery apparatus according to the present invention. As shown in FIG. 1, the vapor recovery device 10 includes a plurality of underground tanks 20 </ b> A to 20 </ b> C, an adsorption tank 30, a vapor recovery path 40, and a control device 50. The control device 50 includes an unloading tank detection unit 60, a collection path switching unit 70, and an adsorption tank control unit 80.

  In the present embodiment, three underground tanks 20 </ b> A to 20 </ b> C are connected in parallel to one adsorption tank 30 through a vapor recovery path 40. In the present embodiment, the configuration in which three underground tanks 20A to 20C are connected in parallel to one adsorption tank 30 via the vapor recovery path 40 is described as an example. Of course, two or three or more underground tanks may be connected to the adsorption tank 30 in parallel.

  Further, in FIG. 1, the illustration of a measuring machine (oil supply device) that pumps up the liquid fuel stored in each of the underground tanks 20 </ b> A to 20 </ b> C and supplies the fuel tank of the vehicle and the management computer that manages the fueling information by the measuring machine is omitted. ing.

  In the present embodiment, the plurality of underground tanks 20A to 20C are tanks having different capacities such as 20KL, 10KL, and 30KL, and store liquid fuel. Examples of the liquid fuel include regular gasoline, high-octane gasoline, light oil, and kerosene. Here, for convenience of explanation, it is assumed that gasoline is stored in each of the underground tanks 20A to 20C. In addition, the underground tanks 20A and 20B are configured to partition the same tank into two chambers with a partition wall, and are substantially two tanks.

  Each of the underground tanks 20A to 20C includes an oil supply pipe 90A to 90C for unloading the liquid fuel loaded in the tank truck, and a ventilation pipe 100A to 100C for preventing an increase and a decrease in the tank internal pressure during the unloading. Is connected. The oil supply pipes 90A to 90C are provided with oil supply ports 92A to 92C to which an unloading hose is connected at the upper end. The upper ends of the vent pipes 100A to 100C extend to a height above the ground. When the tank internal pressure rises to a predetermined pressure or higher (upper limit pressure value), the upper end of the vent pipes 100A to 100C opens and the tank inner pressure becomes lower than the upper limit pressure value. The pressure is reduced to a predetermined pressure, and when the tank internal pressure falls below a predetermined pressure (lower limit pressure value), the valve is opened to hold the tank internal pressure between the upper limit pressure value and the lower limit pressure value. Is provided.

  The adsorption tank 30 is formed of a cylindrical container, and is filled with a granular adsorbent 32 that adsorbs fuel components contained in the vapor.

  When the adsorption tank 30 is divided into four blocks in the vertical direction, temperature sensors (temperature detection means) T1 to T4 for measuring the temperature of each block are attached. As the temperature sensors T <b> 1 to T <b> 4, a temperature detection unit made of a thermocouple or the like and having an explosion-proof structure is inserted into the adsorption tank 30. Further, the temperature sensors T <b> 1 to T <b> 4 measure the temperature of the adsorbent 32 filled at different positions in the height direction, and output an electrical detection signal corresponding to the detected temperature to the control device 50. In addition, the number and installation location of a temperature sensor are not restricted to the said number and installation location. Further, as the temperature sensors T1 to T4, a resistance temperature detector, a thermistor, or the like may be used.

  The vapor collection path 40 includes vapor collection pipes 120A to 120C branched from the middle of the vent pipes 100A to 100C, and a vapor collection common pipe 130 that communicates between the vapor collection pipes 120A to 120C and the lower end of the adsorption tank 30. Have Further, the vapor collection pipes 120A to 120C include pressure transmitters PT1 to PT3 for detecting the pressure (vapor pressure) in the gas phase region of each of the underground tanks 20A to 20C, and an electromagnetic valve (open / close valve) for tank selection. V1 to V3 are provided.

  Further, in the vicinity of the adsorption tank 30 of the vapor recovery common pipe 130, an air supply solenoid valve (open / close valve) V4 that is opened when the vapor is recovered is provided.

  The adsorption tank 30 has an exhaust pipe 140 communicated with the upper end. At the upper end of the exhaust pipe 140, an atmospheric valve 150 is provided, and in the middle of the exhaust pipe 140, an electromagnetic valve (open / close valve) V5 is provided as an exhaust valve that is opened during adsorption. The exhaust pipe 140 communicates with a purge branch pipe 160 that bypasses the upstream side and the downstream side of the electromagnetic valve V5. The purge branch pipe 150 is provided with an adsorption tank purge solenoid valve (open / close valve) V6 that is opened during the desorption purge, and an orifice 170 that restricts the flow path.

  Furthermore, one end of a desorption tube 180 is connected to the lower end of the adsorption tank 30. The other end of the desorption tube 180 is connected to the suction port of the vacuum pump 190. The desorption tube 180 includes a pressure transmitter PT4 that detects the pressure in the adsorption tank 30 at the time of desorption, a demounting electromagnetic valve (open / close valve) V7, a first filter 182 for 40 μm, and a second filter 184 for 10 μm. And are provided.

  The reflux pipe 200 connected to the discharge port of the vacuum pump 190 is connected to the gas phase region of the underground tank 20B. The reflux pipe (reflux path) 200 has one end connected to the discharge port of the vacuum pump 190 and the other end connected to branch pipes 210A to 210C inserted into the gas phase regions of the underground tanks 20A to 20C. In the adsorption tank 30, when a desorption process is performed in which the fuel component adsorbed by the adsorbent 32 is desorbed from the adsorbent 32 with a negative pressure in the adsorbent tank 30, the reflux pipe 200 and the branch pipes 210 </ b> A to 210 </ b> C. The fuel component desorbed via the gas is returned to the underground tanks 20A to 20C, and the fuel component contained in the vapor can be reused.

  At that time, since the internal pressure of other underground tanks that have not been unloaded is lower than the pressure of the underground tank that has undergone unloading, the desorbed fuel components are mainly returned to the other underground tanks. .

  In addition, since the recovered fuel components are returned to the underground tank that has not been unloaded from the tank truck, the storage amount of each of the underground tanks 20A to 20C is reduced by refueling in other underground tanks that have not been unloaded. The volume of the upper space (gas phase region) is larger than the underground tank that has been unloaded. Therefore, in the underground tank that has been unloaded, the amount of fuel stored has reached the upper limit (for example, 90% of the total volume), the volume of the upper space (gas phase region) is small, and the pressure in the tank increases doing. When all of the fuel components collected in the unloading-completed underground tank are recirculated, the pressure of the underground tank is further increased and the breather valves 102A to 102A provided at the upper ends of the vent pipes 100A to 100C. The valve 102C is opened and the vapor in the underground tank is released into the atmosphere, resulting in a problem that the fuel fuel recovery rate of the vapor is reduced.

  However, in this embodiment, the fuel component desorbed in the adsorption tank 30 is returned to each of the underground tanks 20A to 20C by the pressure difference between the pressure at the discharge port of the vacuum pump 190 and the internal pressure of the plurality of underground tanks 20A to 20C. This prevents a large pressure rise in the underground tank that has been unloaded. In addition, by returning the fuel components that have been desorbed to other underground tanks that have not been unloaded, it is possible to disperse the pressure increase in each underground tank. 102A-102C can be prevented from opening.

  In the present embodiment, the configuration in which the fuel component desorbed via the reflux pipe 200 and the branch pipes 210A to 210C is returned to each of the underground tanks 20A to 20C has been described as an example. Of the three underground tanks 20A to 20C, the other end of the reflux pipe 200 may be connected to the large-capacity underground tanks 210A and 210C. When three or more underground tanks are installed, the other end of the reflux pipe 200 may be connected to two or three underground tanks having a larger volume.

  The control device 50 reads each control program stored in the memory, and performs each process (adsorption, adsorption) based on the temperature detected by the temperature sensors T1 to T4 and the pressure value detected by the pressure transmitters PT1 to PT4. Control is performed to open or close the solenoid valves V1 to V7 so that exhaust, desorption, purge, and recirculation) are performed.

  The unloading tank detecting means 60 detects one tank that performs unloading among the underground tanks 20A to 20C. In this embodiment, the pressure transmitters PT1 to PT3 (pressure detectors) that detect pressure changes in the underground tanks 20A to 20C and the pressure values detected by the pressure transmitters PT1 to PT3 are equal to or greater than a predetermined value. And a control program (detection signal output means) for outputting the tank detection signal during unloading.

  In the present embodiment, a case will be described in which it is determined that the tank starts unloading and is being unloaded when the pressure values detected by the pressure transmitters PT1 to PT3 become a predetermined value or more. The means is not limited to the pressure transmitters PT1 to PT3. For example, a sensor or a switch for detecting that the unloading hose of the tank truck is connected to the oil filling ports 92A to 92C is provided, and based on these detection signals. The tank may be configured to determine whether the tank is being unloaded or being unloaded. Or the structure which determines that the said tank is unloading start based on the detection signal from the level gauge provided in each of underground tank 20A-20C instead of pressure transmitter PT1-PT3. It is also good.

  The recovery path switching means 70 performs opening / closing control of each electromagnetic valve so as to switch the vapor recovery path 40 so that the tank detected by the unloading tank detection means 60 communicates with the adsorption tank 30. In the present embodiment, a plurality of electromagnetic valves V1 to V3 provided at locations where each of the underground tanks 20A to 20C communicates with the adsorption tank 30, and an unloading tank detection means 60 among the plurality of electromagnetic valves V1 to V3. A control program (valve control means) for selectively opening any one of the electromagnetic valves V1 to V3 for communicating the detected tank in unloading with the adsorption tank 30;

  The adsorption tank control means 80 supplies vapor generated in the unloading tank into the adsorption tank 30 via the vapor collection path 40 switched by the collection path switching means 70 to adsorb the fuel component contained in the vapor. The electromagnetic valves V1 to V7 are controlled to be opened and closed so as to be attracted to the material 32.

  The adsorption tank control means 80 is a control means (adsorption means 80A, gas discharge means 80B, desorption means 80C, etc.) that performs opening / closing control of the electromagnetic valves V1 to V7 according to each step (adsorption, exhaust, desorption, purge, reflux). Refluxing means 80D). The adsorbing means 80A controls the opening and closing of the electromagnetic valves V1 to V7 so that the vapor generated in the unloading tank is supplied into the adsorption tank 30 and the adsorbent 32 adsorbs the fuel component contained in the vapor. . The gas discharge means 80 </ b> B performs opening / closing control of each electromagnetic valve V <b> 1 to V <b> 7 so that the gas from which the fuel component contained in the vapor is removed in the adsorption tank 30 is discharged to the outside of the adsorption tank 30. The desorption means 80 </ b> C communicates with the inside of the adsorption tank 30 and performs opening / closing control of the electromagnetic valves V <b> 1 to V <b> 7 so as to desorb the fuel component from the adsorbent 32. The recirculation unit 80D performs opening / closing control of the electromagnetic valves V1 to V7 so that the desorbed fuel component is recirculated to any of the plurality of underground tanks 20A to 20C.

  Further, the adsorption tank control means 80 communicates with the upper spaces of the plurality of underground tanks 20 </ b> A to 20 </ b> C and activates the vacuum pump 190 to be adsorbed by the adsorbent 32 in the adsorption tank 30 through the desorption tube 180. The opening and closing control of the solenoid valves V1 to V7 is performed so that the fuel component of the vapor is desorbed and the desorbed fuel component is returned to the plurality of underground tanks 20A to 20C. By communicating each upper space of the plurality of underground tanks 20A to 20C, the pressure of the unloaded underground tank is supplied to other ungrounded underground tanks, and the pressure in the tank is equalized.

  Further, the adsorption tank control means 80 activates the vacuum pump 190 when each pressure value of the underground tanks 20A to 20C detected by the pressure transmitters PT1 to PT3 becomes equal to or less than a predetermined value, and the fuel component from the adsorbent 32 is obtained. Control to start desorption. Therefore, since the adsorption tank 30 is desorbed in a state where the pressure values of the underground tanks 20A to 20C are reduced to a predetermined value or less, the tank pressure remains even if the fuel components desorbed to the underground tanks 20A to 20C are recirculated. An increase in the valve opening pressure of the breather valves 102A to 102C is prevented.

  Moreover, the adsorption tank control means 80 raised the pressure value detected by the pressure transmitters PT1 to PT3 to a predetermined value at which the breather valves 102A to 102C of the vent pipes 100A to 100C communicating with the underground tanks 20A to 20C are opened. Sometimes, the vacuum pump 190 is stopped to suspend the desorption, and the vacuum pump 190 is restarted when the pressure value detected by the pressure transmitters PT1 to PT3 falls below a predetermined value at which the breather valves 102A to 102C are opened. To control.

  Further, the adsorption tank control means 80 desorbs the fuel component of the vapor adsorbed by the adsorbent 32 in the adsorption tank 30, and the desorbed fuel component is not unloaded from the plurality of underground tanks 20A to 20C. Control to return to other underground tanks.

  Here, control processing executed by the control device 50 will be described. FIG. 2 is a flowchart for explaining the vapor collection control process executed by the control device 50.

  In FIG. 2, the control device 50 stops the vacuum pump 190 in S11 and closes the electromagnetic valves V1 to V7 to set an initial state. In next S12, the control state is set to the standby step 1.

  In next S13, it is checked whether or not the standby process 1 is set. In S13, when the standby process 1 is set (in the case of YES), the process proceeds to S14, and the control process N1 waiting for unloading is executed. In next S15, the control state is set to the adsorption process. Then, it progresses to S16. If the standby process 1 is not set in S13 (NO), the process proceeds to S16.

  In S16, it is checked whether or not the adsorption process is set. When the adsorption process is set in S16 (in the case of YES), the process proceeds to S17, and the adsorption process control process A is executed. In next S18, the control state is set to the standby step 2. Then, it progresses to S19. In S16, when the adsorption process is not set (in the case of NO), the process proceeds to S19.

  In S19, it is checked whether or not the control state is set to the standby process 2. In S19, when the control state is set to the standby process 2 (in the case of YES), the process proceeds to S20, and the control process N2 waiting for the metering machine oil supply is executed. In the next S21, the vacuum desorption process is set as the control state. Then, it progresses to S22. In S19, when the control state is not set to the standby process 2 (in the case of NO), the process proceeds to S22.

  In S22, it is checked whether or not the control state is set to the vacuum desorption process. In S22, when the control state is set to the vacuum desorption process (in the case of YES), the process proceeds to S23, and the control process B of the vacuum desorption process is executed. In the next S24, the control state is set to the purge desorption process. Then, it progresses to S25. If the control state is not set to the vacuum desorption process in S22 (NO), the process proceeds to S25.

  In S25, it is checked whether or not the control state is set to the purge / desorption process. In S25, when the control state is set to the purge / desorption process (in the case of YES), the process proceeds to S26, and the control process C of the purge / desorption process is executed. In S25, when the control state is not set to the purge / desorption process (in the case of NO), the process returns to S13 and the processes of S13 to S27 are repeated.

  Next, the control process N1 in the standby process 1 of S14 described above will be described. FIG. 3 is a flowchart for explaining the control process N1 of the standby process 1.

  As shown in FIG. 3, in S31, the electromagnetic valve V7 of the exhaust pipe 140 and the electromagnetic valve V5 of the desorption pipe 180 are opened.

  In the next S32, the timer t4 having the set time 4 set in the standby release timer t4 is started. Subsequently, the process proceeds to S33, in which it is checked whether or not the standby release timer t4 has reached the set time 4. In S33, when the standby release timer t4 reaches the set time 4 (in the case of YES), the process proceeds to S34, where the solenoid valve V7 of the exhaust pipe 140 and the solenoid valve V5 of the desorption pipe 180 are closed, and the adsorption process is finished. To do.

  In next S35, the pressure value detected by the pressure transmitter PT1 is read, and it is checked whether or not the pressure in the underground tank 20A is equal to or higher than a preset pressure P1. The set pressure P1 is an arbitrary pressure value set for determining the start of unloading of the underground tank. As an initial setting, for example, 4.5 PaG is set.

  In S35, when the pressure of the underground tank 20A is not equal to or higher than the preset pressure P1 (in the case of NO), since the unloading is not performed in the underground tank 20A, the process proceeds to S36 and is detected by the pressure transmitter PT2. The obtained pressure value is read and it is checked whether or not the pressure in the underground tank 20B is equal to or higher than a preset pressure P1.

  In S36, when the pressure in the underground tank 20B is not equal to or higher than the preset pressure P1 (in the case of NO), since the unloading is not performed in the underground tank 20B, the process proceeds to S37 and detected by the pressure transmitter PT3. The obtained pressure value is read to check whether the pressure in the underground tank 20C has become equal to or higher than a preset pressure P1.

  In S37, when the pressure in the underground tank 20C is not equal to or higher than the preset pressure P1 (in the case of NO), since the unloading is not performed in the underground tank 20C, the process returns to S35, and the processes in S35 to S37 are performed. repeat. Therefore, pressure changes in the underground tanks 20A to 20C are monitored until the fuel loaded in the tank truck is unloaded from any of the underground tanks 20A to 20C.

  In S35 to S37, when the pressure transmitters PT1 to PT3 detect a pressure increase in any of the underground tanks 20A to 20C (in the case of YES), the control process N1 of the current standby process 1 is terminated. To do.

  Next, the control process A of the adsorption process of S20 described above will be described. FIG. 4A is a flowchart for explaining the control process A of the adsorption process. FIG. 4B is a flowchart for explaining a control process executed subsequent to the control process of FIG. 4A.

  As shown in FIG. 4A, in S41, whether or not the pressure value detected by the pressure transmitter PT1 is read and the pressure in the underground tank 20A is equal to or higher than a preset pressure P1 (unloading start determination pressure). Check. In S41, when the pressure in the underground tank 20A is equal to or higher than the preset pressure P1 (in the case of YES), since the unloading is performed in the underground tank 20A, the process proceeds to S42, and the vapor recovery in the underground tank 20A is performed. The electromagnetic valve V1 provided in the pipe 120A is opened.

  In S41, when the pressure in the underground tank 20A is not equal to or higher than the preset pressure P1 (in the case of NO), since the unloading is not performed in the underground tank 20A, the process proceeds to S43, and the pressure transmitter The pressure value detected by PT2 is read, and it is checked whether or not the pressure in the underground tank 20B is equal to or higher than a preset pressure P1 (unloading start determination pressure).

  In S43, when the pressure in the underground tank 20B is equal to or higher than the preset pressure P1 (in the case of YES), since the unloading is performed in the underground tank 20B, the process proceeds to S44 and the vapor recovery in the underground tank 20B is performed. The electromagnetic valve V2 provided in the pipe 120B is opened.

  In S43, when the pressure in the underground tank 20B is not equal to or higher than the preset pressure P1 (in the case of NO), since the unloading is not performed in the underground tank 20B, the process proceeds to S45, and the pressure transmitter The pressure value detected by PT3 is read to check whether or not the pressure in the underground tank 20C is equal to or higher than a preset pressure P1 (unloading start determination pressure).

  In S45, when the pressure in the underground tank 20C is equal to or higher than a preset set pressure (in the case of YES), since the unloading is performed in the underground tank 20C, the process proceeds to S46 and the vapor recovery pipe of the underground tank 20C is obtained. The electromagnetic valve V3 provided at 120C is opened.

  In S45, when the pressure in the underground tank 20C is not equal to or higher than the preset pressure P1 (in the case of NO), since the unloading is not performed in the underground tank 20C, the control process of the present adsorption process Exit A.

  Further, when a pressure increase is detected in any of the underground tanks 20A to 20C by the pressure transmitters PT1 to PT3, it is determined that unloading is started in the underground tank in which the pressure increase is detected. Proceed to S47. In S47, the electromagnetic valve V4 communicated with the lower end side (supply side) of the adsorption tank 30 and the electromagnetic valve V5 communicated with the upper end side (exhaust side) of the adsorption tank 30 are opened. The process of S41 to S46 is an underground tank pressure monitoring process 1 for monitoring the unloading state of each of the underground tanks 20A to 20C.

  By this underground tank pressure monitoring process 1, unloading is performed by selecting one of the solenoid valves V1 to V3 based on the pressure change of the underground tanks 20A to 20C detected by the pressure transmitters PT1 to PT3. The tank is identified, and vapor from the gas phase region of the selected underground tank being unloaded is supplied to the adsorption tank 30.

  In next S48, the set time 1 is set in the suction time timer t1, and the suction time timer t1 is started. The set time 1 is an adsorption time in the adsorption tank 30 and is an arbitrary set time required for completing the unloading of the underground tank (for example, 1 hour in the initial setting).

  Subsequently, in S49, it is checked whether or not the adsorption time timer t1 has reached the set time 1. In S49, when the adsorption time timer t1 has not reached the set time 1 (in the case of NO), the process proceeds to S50, and the underground tank pressure monitoring process 2 of S50 to S55 is executed. Since this underground tank pressure monitoring process 2 is the same as the process of said S41-S46, these description is abbreviate | omitted.

  In S49, when the adsorption time timer t1 reaches the set time 1 (in the case of YES), the process proceeds to S56, and the solenoid valves V1 to V3 are closed to stop the vapor collection, and S50 to S55. End the underground tank pressure monitoring process. Subsequently, in S57, the set time 2 is set in the suction end determination timer t2, and the suction end determination timer t2 is started.

  As shown in FIG. 4B, in the next S58, it is checked whether or not the adsorption end determination timer t2 has reached the set time 2. The set time 2 is an adsorption end determination time for determining whether the adsorption process by the adsorption tank 30 is completed, and according to the capacity of the underground tanks 20A to 20C in order to determine whether or not the underground tank is being unloaded. It is an arbitrary set time (for example, 1 minute in the initial setting).

  In S58, when the adsorption end determination timer t2 has not reached the set time 2 (in the case of NO), the process proceeds to S59, and the underground tank pressure monitoring process 3 in S59 to S64 is executed. Since this underground tank pressure monitoring process 3 is the same as the process of said S41-S46, these description is abbreviate | omitted.

  In S58, when the adsorption end determination timer t2 reaches the set time 2 (in the case of YES), the process proceeds to S65, and it is checked whether or not the electromagnetic valve V1 of the underground tank 20A is opened. In S65, when the solenoid valve V1 of the underground tank 20A is not opened (in the case of NO), the process proceeds to S66, and it is checked whether or not the solenoid valve V2 of the underground tank 20B is opened. In S66, when the electromagnetic valve V2 of the underground tank 20B is not opened (in the case of NO), the process proceeds to S67 and it is checked whether or not the electromagnetic valve V3 of the underground tank 20C is opened.

  In S65 to S67, when any of the solenoid valves V1 to V3 is open (in the case of YES), since the unloading to the underground tank is still continued, the process proceeds to S68, and the adsorption extension timer t3 Is set to a set time 3 and the suction end determination timer t3 is started. It is checked whether or not the suction extension timer t3 has reached the set time 3. The set time 3 is an adsorption extension determination time for determining whether the adsorption process is extended after the adsorption process by the adsorption tank 30 is completed, and is an arbitrary value for extending the determination of whether or not the underground tank is being unloaded. Set time (for example, 30 minutes in the initial setting).

  In the next S69, it is checked whether or not the set time t3 has elapsed. In S69, the unloading to the underground tank is extended until the set time t3 elapses, and the adsorption process by the adsorption tank 30 is also extended. In S69, when the set time t3 has elapsed (in the case of YES), the process proceeds to S70, the solenoid valves V1 to V3 are closed, the vapor collection is stopped, and the vapor collection extension process is terminated.

  In S67, when the solenoid valve V3 of the underground tank 20C is not opened (in the case of NO), the solenoid valves V1 to V3 are all closed, so the process proceeds to S71 and the lower end of the adsorption tank 30 is reached. Then, the solenoid valves V4 and V5 communicated with the upper end are closed, and the vapor recovery (vapor adsorption) is completed. This completes the control process of the adsorption process.

  Next, the control process N2 waiting for the metering machine refueling after the above-described adsorption process of S20 will be described. FIG. 5 is a flowchart for explaining the control process N2 of the standby process 2.

  As shown in FIG. 5, in S81, the pressure value detected by the pressure transmitter PT1 is read to check whether or not the pressure in the underground tank 20A is equal to or higher than a preset pressure P3. The set pressure P3 is an arbitrary pressure value set to determine the free capacity of the underground tanks 20A to 20C, and is set to 0 kPa as an initial set value, for example.

  In S81, when the pressure in the underground tank 20A is not equal to or higher than the preset pressure P3 (in the case of NO), since the unloading is not performed in the underground tank 20A, the process proceeds to S82 and is detected by the pressure transmitter PT2. The obtained pressure value is read to check whether or not the pressure in the underground tank 20B has become equal to or higher than a preset pressure P3.

  In S82, when the pressure in the underground tank 20B is not equal to or higher than the preset pressure P3 (in the case of NO), since the unloading is not performed in the underground tank 20B, the process proceeds to S83 and is detected by the pressure transmitter PT3. The obtained pressure value is read to check whether or not the pressure in the underground tank 20C has become equal to or higher than a preset pressure P3.

  In S83, when the pressure in the underground tank 20C is not equal to or higher than the preset set pressure P3 (in the case of NO), since the unloading is not performed in the underground tank 20C, the process returns to S81, and the processes in S81 to S83 are performed. repeat. Therefore, pressure changes in the underground tanks 20A to 20C are monitored until the fuel loaded in the tank truck is unloaded from any of the underground tanks 20A to 20C.

  In S81 to S83, when the pressure transmitters PT1 to PT3 detect a pressure increase in any of the underground tanks 20A to 20C (in the case of YES), the control process N1 of the current standby process 1 is terminated. To do.

  Next, the control process B of the desorption process of S23 described above will be described. FIG. 6 is a flowchart for explaining the control process B of the desorption process.

  As shown in FIG. 6, in S101, a set time 5 is set in the vacuum desorption timer t5, and the vacuum desorption timer t5 is started. For example, 4 hours is set as the initial setting value of the setting time 5.

  In the next S102, the set time 8 is set in the free space shortage determination timer t8, and the free space shortage determination timer t8 is started. For example, 1 minute is set as the initial setting value of the setting time 8.

  In the next step S103, the vacuum pump 190 is started, the electromagnetic valve V7 of the desorption tube 180 is opened to allow communication between the adsorption tank 30 and the vacuum pump 190, and the electromagnetic valves V1 to V3 are opened. The upper spaces of the underground tanks 20A to 20C at the time of desorption are communicated. Thereby, the pressure of the ungrounded underground tank is supplied to the other ungrounded underground tank, and the internal pressure of the underground tanks 20A to 20C is equalized. Further, since the desorbed fuel component is returned to the entire volume of the upper space of each underground tank 20A-20C, each desorbed fuel component is returned to each underground tank 20A-20C. An increase in tank pressure in the tanks 20A to 20C is suppressed, and an increase above the valve opening pressure (upper pressure value) of the breather valves 102A to 102C is suppressed.

  Therefore, the fuel component desorbed by the vacuum pump 190 is returned to the underground tanks 20A to 20C through the reflux pipe 200 and the branch pipes 210A to 210C due to a pressure difference with the underground tanks 20A to 20C. At that time, the pressure of the underground tank that has undergone unloading is higher than the pressure of the other underground tanks, and among the underground tanks 20A to 20C, most of the fuel components are unloaded, Refluxed. Also from this, even if the desorbed fuel component is recirculated to the underground tanks 20A to 20C, the tank pressure is prevented from rising above the opening pressure (upper limit pressure value) of the breather valves 102A to 102C.

  In next S104, the pressure value detected by the pressure transmitter PT1 is read to check whether or not the pressure in the underground tank 20A is equal to or higher than a preset pressure P2 (first pressure value). The set pressure P2 is an arbitrary pressure value set for determining desorption interruption, and is set to, for example, 4.0 kPaG as an initial set value.

  In S104, when the pressure in the underground tank 20A is not equal to or higher than the preset pressure P2 (in the case of NO), the pressure in the underground tank 20A has not reached the desorption interruption pressure, so the process proceeds to S107.

  In S104, when the pressure in the underground tank 20A is equal to or higher than the preset pressure P2 (in the case of YES), the pressure in the underground tank 20A has reached the desorption interruption pressure. The pressure value detected by the vessel PT2 is read to check whether or not the pressure in the underground tank 20B is equal to or higher than a preset pressure P2.

  In S105, when the pressure in the underground tank 20B is not equal to or higher than the preset pressure P2 (in the case of NO), the pressure in the underground tank 20B has not reached the desorption interruption pressure, so the process proceeds to S107.

  In S105, when the pressure in the underground tank 20B is equal to or higher than the preset set pressure P2 (in the case of YES), the pressure in the underground tank 20B has reached the desorption interruption pressure, so the process proceeds to S106 to transmit pressure. The pressure value detected by the vessel PT3 is read to check whether or not the pressure in the underground tank 20C has become equal to or higher than a preset pressure P2.

  In S106, when the pressure in the underground tank 20C is not equal to or higher than the preset pressure P2 (in the case of NO), since the pressure in the underground tank 20C has not reached the desorption interruption pressure, the process proceeds to S107.

  In S106, when the pressure in the underground tank 20C is equal to or higher than the preset set pressure P2 (in the case of YES), the pressure in the underground tank 20C has reached the desorption interruption pressure, so the process proceeds to S111.

  In S107, it is checked whether or not the pressure determination method is set. If the pressure determination method is set in S107 (in the case of YES), the process proceeds to S108, the pressure value detected by the pressure transmitter PT4 of the desorption tube 180 is read, and the pressure on the lower end side of the adsorption tank 30 is atmospheric pressure. Check if the following (vacuum) has been reached. In this embodiment, in S108, it is checked whether or not the pressure value detected by the pressure transmitter PT4 is equal to or less than a preset value (for example, 2 kPaA).

  In S108, when the pressure on the lower end side of the adsorption tank 30 is not lowered to the atmospheric pressure (vacuum) (in the case of NO), the process returns to S104, and S104 and subsequent steps are repeated. In S108, when the pressure on the lower end side of the adsorption tank 30 drops below atmospheric pressure (vacuum) (in the case of YES), since the desorption of the adsorption tank 30 is completed, the process proceeds to S109 and the vacuum desorption timer t5 is stopped. . Thus, it is determined that the desorption process for the adsorption tank 30 has been completed, and the control process B ends.

  In S107, when the pressure determination method is not set (in the case of NO), it is determined that the time determination method is set, and the process proceeds to S110, and whether the vacuum desorption timer t5 has reached the set time 5 or not. To check. In S110, when the vacuum desorption timer t5 has not reached the set time 5 (in the case of NO), the process returns to S104, and S104 and subsequent steps are repeated. In S110, when the vacuum desorption timer t5 reaches the set time 5 (in the case of YES), it is determined that the desorption process for the adsorption tank 30 is completed, and the control process B is terminated.

  In S104 to S106, when the pressures in the upper spaces of the underground tanks 20A to 20C at the time of desorption are all equal to or higher than the set pressure P2 (first pressure value) (in the case of YES), the process proceeds to S111, and the adsorption tank 30 It is determined that the pressure in the upper space of each of the underground tanks 20A to 20C has increased due to the reflux of the fuel component desorbed from the adsorbent 32, and the vacuum pump 190 is stopped, and the solenoid valves V1 to V3 and the desorption pipe The 180 solenoid valve V7 is closed. Thereby, the desorption process in the adsorption tank 30 stops, and it will be in the desorption interruption state.

  Then, it progresses to S112, the elapsed time of the vacuum desorption timer t5 is memorize | stored in memory, and the vacuum desorption timer t5 is stopped. In S113, the desorption interruption process P is executed.

  In the next S114, the storage elapsed time of the vacuum desorption timer t5 is set to the set time, and the vacuum desorption timer t5 is started. In the next step S115, the vacuum pump 190 that has been stopped due to the desorption interruption is restarted to restart the desorption process, and the electromagnetic valve V7 of the desorption pipe 180 is opened to open the space between the adsorption tank 30 and the vacuum pump 190. And the electromagnetic valves V1 to V3 are opened, and the pressures in the upper spaces of the underground tanks 20A to 20C at the time of desorption are detected by the pressure transmitters PT1 to PT3. Thereafter, the process returns to S104, and the processes after S104 are executed.

  Here, the desorption interruption process P in S113 will be described. FIG. 7 is a flowchart for explaining the control process of the desorption interruption process P. As shown in FIG. 7, in S121, it is checked whether or not the elapsed time of the free space shortage determination timer t8 has reached a predetermined set time 8. In S121, when the elapsed time of the free space shortage determination timer t8 has not reached the predetermined set time 8 (in the case of NO), the process proceeds to S122, where the set time 6 is set in the tank free wait timer t6 and the tank free wait timer is set. Start t6. For example, 30 minutes is set as the initial setting value of the setting time 6.

  In next S123, it is checked whether or not the elapsed time of the tank empty waiting timer t6 has reached the set time 6. In this S123, it is in a standby state until the elapsed time of the tank empty waiting timer t6 reaches the set time 6, and when the set time 6 is reached, the process proceeds to S124. In S121, when the elapsed time of the free space shortage determination timer t8 reaches the predetermined set time 8 (in the case of YES), the process proceeds to S124, and the pressure value detected by the pressure transmitter PT1 is read and the underground It is checked whether or not the pressure in the tank 20A has become equal to or lower than a preset pressure P3 (second pressure value). The set pressure P3 is an arbitrary pressure value that is set to determine the tank free capacity, that is, to determine whether or not the tank free capacity has a sufficient volume to resume desorption. For example, the initial set value is set to atmospheric pressure.

  In S124, when the pressure of the underground tank 20A is not equal to or lower than the preset set pressure P3 (in the case of NO), the pressure of the underground tank 20A has not reached the determination pressure of the tank free capacity, so the process proceeds to S125.

  In S124, when the pressure of the underground tank 20A drops below the preset pressure P3 (in the case of YES), the pressure of the underground tank 20A has reached the determination pressure of the tank free capacity. The desorption interruption process P is terminated.

  In S125, the pressure value detected by the pressure transmitter PT2 is read to check whether or not the pressure in the underground tank 20B has become equal to or lower than a preset pressure P3. In S125, when the pressure of the underground tank 20B is not equal to or lower than the preset pressure P3 (in the case of NO), the pressure of the underground tank 20B has not reached the determination pressure of the tank free capacity, and the process proceeds to S126.

  Further, in S125, when the pressure in the underground tank 20B drops below the preset set pressure P3 (in the case of YES), the pressure in the underground tank 20B has reached the determination pressure of the tank free capacity. The desorption interruption process P is terminated.

  In S126, when the pressure of the underground tank 20C is not lower than the preset set pressure P3 (in the case of NO), the pressure of the underground tank 20C has not reached the determination pressure of the tank free capacity, so the process returns to S124, The tank internal pressure monitoring process in S124 to S126 is repeated.

  In S126, when the pressure in the underground tank 20C drops below the preset pressure P3 (in the case of YES), since the pressure in the underground tank 20C has reached the tank free capacity determination pressure, this time The desorption interruption process P is terminated.

  Therefore, in S124 to S126, when the pressure in the upper space of any of the underground tanks 20A to 20C becomes equal to or lower than the set pressure P3 due to fueling the vehicle (in the case of YES), it is desorbed in the adsorption tank 30. Since the fuel component can be returned to the underground tank whose pressure has dropped to the set pressure P3 or lower among the underground tanks 20A to 20C, the desorption interruption process P is terminated. That is, when any one of the underground tanks 20A to 20C is lowered by refueling the vehicle, the fuel component desorbed in the adsorption tank 30 is discharged from the discharge port of the vacuum pump 190 and each of the underground tanks 20A to 20C. It is recirculated by the pressure difference from the internal pressure of 20C. Therefore, since the branch pipes 210A to 210C communicated with the other end of the reflux pipe 200 are connected in parallel to the underground tanks 20A to 20C, the underground tanks in which the tank internal pressure is reduced (the underground tanks having a large pressure difference) ) And the return to another underground tank with a small pressure difference is automatically suppressed.

  Next, the control process C of the purge desorption process of S26 described above will be described. FIG. 8 is a flowchart for explaining the purge / desorption process. As shown in FIG. 8, in S131, a set time 7 is set in the purge / desorption time timer t7, and the purge / desorption time timer t7 is started. As an initial setting value of the setting time 7, for example, 4 hours is set.

  In the next S132, the set time 8 is set in the free space shortage determination timer t8, and the free space shortage determination timer t8 is started. For example, 1 minute is set as the initial setting value of the setting time 8.

  Subsequently, in S133, the purge solenoid valve V6 provided in the purge branch pipe 160 is opened.

  Since the next processing of S134 to S141 is the same as the processing of S104 to S106 and S111 to S115 described above, description thereof will be omitted.

  In S134 to S136, when the pressure of the underground tank 20B is not equal to or higher than the preset set pressure P2 (in the case of NO), the pressure of the underground tank 20B has not reached the desorption interruption pressure, so the process proceeds to S142. In S142, it is checked whether or not the elapsed time of the purge / desorption time timer t7 has reached the set time 7. In S142, when the elapsed time of the purge / desorption time timer t7 does not reach the set time 7 (in the case of NO), the process returns to S134, and the processes after S134 are repeated. In S142, when the elapsed time of the purge desorption time timer t7 reaches the set time 7 (in the case of YES), the process proceeds to S134, and it is determined that the desorption process of the adsorption tank 30 with respect to the adsorbent 32 is completed, The vacuum pump 190 is stopped, and the solenoid valves V1 to V3 and the solenoid valve V7 of the desorption tube 180 are closed. Thereby, the desorption process in the adsorption tank 30 stops.

  Here, a modified example will be described.

  FIG. 9 is a system configuration diagram showing a modification of the vapor recovery apparatus. As shown in FIG. 9, in the vapor recovery apparatus 10 </ b> A of the modified example, electromagnetic valves (open / close valves) V <b> 8 to V <b> 10 are provided in the branch pipes 210 </ b> A to 210 </ b> C communicated with the other end of the reflux pipe 200.

  The control device 50 detects the tank pressure of the underground tanks 20A to 20C by pressure transmitters PT1 to PT3 at the time of desorption, and the solenoid valve communicated with the underground tank having the lowest tank pressure among the solenoid valves V8 to V10. Is selectively opened.

  As a result, the desorbed fuel component is prevented from returning to the underground tank immediately after completion of unloading at a high tank pressure among the underground tanks 20A to 20C, and returned to another underground tank that has not been unloaded. Will be. Therefore, when the desorbed fuel component is returned to any of the underground tanks 20A to 20C, the breather valves 102A to 102C of the vent pipes 100A to 100C are prevented from opening due to an increase in tank pressure, Vapor is prevented from being released into the atmosphere.

  Moreover, in this modification, it is also possible to selectively open the solenoid valves (open / close valves) communicated with the other two underground tanks except the underground tank having the highest tank pressure among the solenoid valves V8 to V10. It is. In this case, the fuel component of the vapor adsorbed on the adsorbent 32 of the adsorption tank 30 by unloading can be returned to a plurality of underground tanks excluding the underground tank immediately after completion of the unloading, and the pressure of the underground tanks 20A to 20C The burden can be reduced efficiently.

  In the above embodiment, the case where the liquid fuel loaded in the tank truck is unloaded to the underground tank has been described as an example. However, the present invention is not limited to this. For example, the liquid fuel is stored on the ground from the tank in which the liquid fuel is stored. Of course, the present invention can also be applied to the case of supplying to another installed tank.

  Moreover, in the said Example, although the structure which provided the solenoid valves V1-V10 as an on-off valve was illustrated and demonstrated, it is not restricted to this, The opening and closing of the air operation system which opens and closes by supply of air pressure instead of an electromagnetic valve A valve may be used. In addition, when an air-operated on-off valve is arranged at a location where the oil liquid comes into contact, an electrical control signal from the control device is provided by providing an electromagnetic valve for controlling the air pressure in a path for supplying air pressure to each on-off valve. Can be converted into an air signal to control each on-off valve.

DESCRIPTION OF SYMBOLS 10 Vapor collection apparatus 20A-20C Underground tank 30 Adsorption tank 32 Adsorbent 40 Vapor collection path 50 Control apparatus 60 Unloading tank detection means 70 Collection path switching means 80 Adsorption tank control means 80A Adsorption means 80B Gas discharge means 80C Desorption means 80D Reflux Means 90A-90C Lubricating pipes 92A-92C Lubricating ports 100A-100C Ventilation pipes 102A-102C Breather valves 120A-120C Vapor recovery pipe 130 Recovery common pipe 140 Exhaust pipe 150 Air valve 160 Purge branch pipe 180 Desorption pipe 190 Vacuum pump 200 Reflux pipes 210A to 210C Branch pipes PT1 to PT4 Pressure transmitters T1 to T4 Temperature sensors V1 to V10 Solenoid valves (open / close valves)

Claims (2)

A plurality of tanks in which liquid fuel is unloaded;
An adsorption tank filled with an adsorbent for adsorbing vapor evaporated from the liquid fuel;
A desorption path communicating the suction tank and the suction port of the vacuum pump;
A reflux path communicating the discharge port of the vacuum pump and the plurality of tanks;
An adsorption process is performed in which the vapor discharged from the tank during unloading is supplied into the adsorption tank and the fuel component contained in the vapor is adsorbed by the adsorbent, and the fuel component contained in the vapor is adsorbed. Control means for performing a desorption step of desorbing the fuel component from the adsorbent after being adsorbed in a tank, and controlling the desorbed fuel component to be recirculated to the plurality of tanks via the recirculation path; A vapor recovery device comprising:
Wherein, when performing the desorption step, the desorbing fuel components adsorbed vapor to the adsorbent before Symbol in the adsorption vessel through the desorption path by activating the vacuum pump, which is said desorbing A vapor recovery apparatus for returning a fuel component to another tank that is not unloaded among the plurality of tanks. An opening / closing valve for reflux is provided in each of the branch paths of the reflux path communicating with the plurality of tanks;
The control means selectively opens the plurality of on-off valves so as to return the desorbed fuel component to another tank that is not unloaded among the plurality of tanks. vapor recovery device according to 1.

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