JP3593274B2 - Storage tank residual quantity management system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a remaining amount management system in a storage tank, and more particularly, to a remaining amount management system in a storage tank for managing a remaining amount of a liquid material such as a liquefied gas in the storage tank.
[0002]
[Prior art]
Conventionally, for example, the remaining amount (storage amount) in a storage tank containing a liquid material such as a liquefied gas is sequentially checked by an administrator of the storage tank. We have contacted the supplier. Then, the supplier that has received the notification dispatches a tank truck loaded with the liquid material, and fills the storage tank with which the tank truck has been contacted with the liquid material. Here, since the supply source generally does not know the exact remaining amount in the storage tank that has been notified, the vehicle is dispatched in a state where the tank lorry is full of liquid matter.
[0003]
[Problems to be solved by the invention]
However, in the case of allocating a tank lorry while the exact remaining amount in the storage tank is unknown as in the above-described conventional example, there are the following problems.
[0004]
First, when the amount of the liquid material in the storage tank is slightly decreased and the remaining amount is large, the filling amount from the tank truck to the storage tank is small, and a large amount of the liquid material remains in the tank truck returned to the supply source. For this reason, a large amount of liquid material remaining in the tank lorry must be returned to the large storage tank at the supply source, which is enormous.
[0005]
On the other hand, when the amount of the liquid material in the storage tank is remarkably reduced and the remaining amount is small, the required filling amount of the storage tank may not be sufficient for the mounting amount of the tank lorry. Then, in such a case, there is a problem that labor such as arranging another tank lorry or arranging the same tank lorry again is required.
[0006]
The above-mentioned problems are particularly remarkable when, for example, a tank lorry patrols a large number of storage tanks to perform replenishment. Therefore, it is difficult to efficiently distribute the tank lorry, and the distribution cost increases. It is a factor.
[0007]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a storage tank remaining amount management system capable of accurately monitoring the remaining amount in a storage tank and thereby efficiently distributing the tank truck to reduce the allocation cost. Things.
[0008]
[Means for Solving the Problems]
A storage tank remaining amount management system according to the present invention includes a storage tank for storing and storing a liquid material therein, and a liquid level detector for measuring a liquid level of the liquid material in the storage tank. 2 and the remaining volume of the liquid material remaining in the storage tank 1 is calculated from the liquid level, and a predetermined warning value is provided via the communication device 4 to the monitoring center 5 on the liquid material supply source side. The contact signal and the open-collector signal for turning on the alarm circuit at the same time as sending a telegram signal to the administrator of the storage tank 1 when the remaining volume of the liquid material becomes equal to or less than a predetermined warning value. Is issued from the alarm processing unit (35) on the manager side, and this warning is notified to the monitoring center 5 via the communication device 4, and the remaining data on the manager side of the storage tank 1 is transmitted. Quantity monitoring device 3 and before The remaining amount monitoring device 3 calculates the remaining volume of the liquid material from the liquid level based on the relationship between the liquid level and the storage volume defined by the internal shape of the storage tank 1, and calculates the remaining volume of the liquid material. information, and a said communication device 4 for bidirectional communication between the monitoring center 5 and the remaining amount monitoring device 3 connected to the storage tank 1, the warning via the communication device 4 related In this case, the monitoring center 5 is notified . Further, the predetermined warning value can be set in the monitoring center 5 via the communication device 4.
[0009]
[0010]
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of a tank remaining amount management system according to the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows a remaining amount management system in a storage tank according to an embodiment of the present invention. This remaining amount management system in a storage tank includes a storage tank 1, a liquid level detector 2, a remaining amount monitoring device 3, a communication device 4, a monitoring center 5, and the like. Here, for example, the storage tank 1 to the communication device 4 belong to the manager of the storage tank 1, and the monitoring center 5 belongs to the supply side of the liquid material that fills the storage tank 1 with the liquid material.
[0012]
The storage tank 1 stores and stores a liquid material such as a high-pressure liquefied gas (LPG or the like) therein. The storage tank 1 has a unique shape. In the example shown,
The storage tank 1 has a spherical outer shape and an inner shape (liquid material storage space).
Those having an appropriate shape can be used.
[0013]
Here, in the storage tank 1, the calculation of the remaining volume for each shape is performed by inserting, for example, five constants produced from the tank shape. That is, the relationship between the liquid level X of the liquid material inside the tank and the storage volume (capacity) V is known, for example, in a table for each tank. However, since the shape of the storage tank 1 is slightly different for each tank, the capacity of the liquid material located at a certain height in the tank is different. Therefore, a quartic equation that can be applied to the data in the table with the minimum error is obtained by the least square method, and is used as an arithmetic expression. For example, calculations are performed by inserting constants into V = AX4 + BX3 + CX2 + DX + E. However, it is needless to say that the present invention is not limited to this method and may be modified by another method.
[0014]
This relationship is stored in the memory unit 33 of the remaining amount monitoring device 3 as described later, for example, as a calculation formula using a function of an appropriate order (for example, a quartic function) or a table (correspondence table). It is.
[0015]
The liquid level detector 2 is for measuring the liquid level of the liquid material in the storage tank 1, that is, the liquid level position. Specifically, for example, a part of the liquid level detector 2 is provided inside the storage tank 1, and a resistance whose resistance value increases and decreases as the liquid level of the liquid material in the storage tank 1 increases and decreases. Have. More specifically, as shown in FIG. 3, a resistor 21 having terminals 211 to 213 is provided, and a terminal 212 is provided integrally with a known float or the like and moves up and down the liquid level of the liquid material in the storage tank 1. Move with. Then, a resistance value that changes according to the remaining amount of the tank can be obtained from the terminal 212 and the terminal 213. Thus, a signal corresponding to the voltage ratio, that is, an analog voltage ratio signal can be obtained.
[0016]
The remaining amount monitoring device 3 is composed of, for example, a computer provided with software for executing necessary operations. The remaining amount monitoring device 3 includes a digital filter unit 31, a volume calculating unit 32, a memory unit 33, a remaining amount calculating unit 34, an alarm processing unit 35, a display unit 36, and the like.
[0017]
The digital filter unit 31 reads the analog voltage ratio signal input from the liquid level detector 2, performs A / D conversion on the signal, and cuts such fluctuation when the signal fluctuates greatly up and down in a short time. This function prevents output to the volume calculation unit 32 at the next stage. For example, by providing such a digital filter section 31, when a liquefied gas is stored in the storage tank 1, an error in the liquid level due to chattering caused by bubbles generated from the liquefied gas due to boiling of the liquid level or the like is caused. Detection can be prevented.
[0018]
The volume calculation unit 32 calculates the volume (storage volume) of the liquid material remaining in the storage tank 1 based on the digital signal from the digital filter unit 31. This calculation is performed by referring to the above-described function or table stored in the memory unit 33. The reading of the signal and the calculation of the storage volume in the volume calculation unit 32 are performed at a predetermined timing, for example, once a second, and are constantly updated to the latest measured values.
[0019]
In addition to the function or the table described above, the storage volume of the storable liquid material having a different capacity with respect to the liquid level for each storage tank 1 is stored in the memory unit 33 in advance. That is, this type of tank has a different shape even if it is spherical in shape, and has a different volume for a certain height. Therefore, it is necessary to store the information for each tank corresponding to each tank.
[0020]
The remaining percentage calculating unit 34 calculates the storage volume (V) of the liquid material input from the volume calculating unit 32 and the storage volume (V0) of the liquid material that can be stored in the storage tank 1 and input from the memory unit 33. Accordingly, the remaining amount% (R) of the liquid material in the storage tank 1 is calculated based on the following equation.
[0021]
(Equation 1)
R = (V / V0) × 100
[0022]
The display unit 36 is for displaying the remaining amount% calculated by the remaining amount calculating unit 34. For display, digital display or analog display using, for example, a liquid crystal or LED is used.
[0023]
When the remaining amount% of the liquid material in the storage tank 1 calculated by the remaining amount% calculating unit 34 becomes equal to or less than a predetermined value (warning value), the alarm processing unit 35, for example, an administrator of the storage tank 1 A warning signal is issued by transmitting a message signal composed of, for example, 8 bits or 5 bits, such as sound or light, and simultaneously transmitting a contact signal for turning on the switch of the alarm circuit and an open collector signal. In this case, a warning can be issued via a telephone line. Note that the warning value can be manually set on the spot in the remaining amount monitoring device 3, or can be remotely set from the monitoring center 5 via a communication device 4 such as a telephone line as described later. Yes, it is interactive.
[0024]
The communication device 4 is configured by a known modem or the like, and is for transmitting information to and from the monitoring center 5. Specifically, the communication device 4 transmits the remaining amount% calculated above to the monitoring center 5. When a warning is generated in the warning processing unit 35, the communication device 4 notifies the monitoring center 5 of the warning. The communication device 4 and the monitoring center 5 are connected by a wired network or a wireless network including optical communication, and are characterized by having bidirectionality.
[0025]
The monitoring center 5 is composed of, for example, a computer having software for performing necessary operations. The monitoring center 5 inputs the remaining percentage of the volume of the liquid material in the storage tank 1 communicated from the remaining amount monitoring device 3 via the communication device 4 at a predetermined timing, and monitors the remaining amount%. I do.
[0026]
Further, the monitoring center 5 receives a warning input from the remaining amount monitoring device 3 via the communication device 4 and issues a warning using a known means such as a voice or light. Further, as described above, the monitoring center 5 can appropriately set or change the warning value in the warning processing unit 35 of the remaining amount monitoring device 3 via the communication device 4.
[0027]
Next, the operation of the tank remaining amount management system according to the present embodiment will be described with reference to the flowchart of FIG. First, an analog voltage ratio signal indicating the liquid level of the liquid material detected by the liquid level detector 2 is read out at a predetermined timing by the remaining amount monitoring device 3 (step S1). The volume calculating section 32 calculates the volume of the liquid remaining in the storage tank 1 based on the read liquid level, that is, the liquid level position (step S2), and calculates the remaining amount%. In, the remaining amount% of the liquid material in the storage tank 1 is calculated (step S3). This remaining amount% is displayed on the display unit 36 (step S4).
[0028]
Next, in the alarm processing unit 35, it is determined whether or not the calculated remaining amount% is equal to or less than a warning value (step S5). If “NO” in the step S5, the process returns to the step S1. On the other hand, if “YES” in the step S5, the remaining amount% calculated this time is
It is determined whether it is smaller than the previously calculated remaining amount% (step S6). If "NO" in the step S6, the process returns to the step S1. On the other hand, if “YES” in the step S6, a warning is issued from the warning processing unit 35 (step 7).
[0029]
Here, by adding the process of step S6, it is possible to prevent the occurrence of a warning when the liquid material that has been reduced to the warning value or less is filled.
[0030]
According to the remaining amount management system in the storage tank configured as described above, the accurate remaining amount of the liquid material in the storage tank 1 can be constantly monitored on the storage tank management side and the supply source of the liquid material. For this reason, at the supply source of the liquid material, it is possible to reliably load an appropriate amount of the liquid material without excessively filling the liquid truck with a tank truck that is arranged for filling the storage tank.
[0031]
【The invention's effect】
According to the storage tank remaining amount management system of the first aspect of the present invention, the accurate remaining volume of the liquid material in the storage tank can be monitored from both the storage tank installation location and the monitoring center. For this reason, it is possible to efficiently allocate the tank lorry for filling the storage tank with the liquid material, and it is possible to reduce the allocation cost. Further, according to the management system of the remaining amount in the storage tank, it is possible to easily know from the alarm output that the remaining volume in the storage tank has become equal to or less than a predetermined warning value. Further, there is an advantage that a warning is not issued at the time of filling. Then, the warning value can be set or changed at the supply source of the liquid material, that is, at the monitoring center.
According to the remaining amount management system in the storage tank according to the second aspect of the invention, the warning value can be set or changed on the storage tank management side (site).
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an outline of a remaining amount management system in a storage tank according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a relationship between a storage tank and a storage volume in the storage tank remaining amount management system of FIG. 1;
FIG. 3 is an explanatory diagram of a main part of a liquid level detector of the remaining amount management system in the storage tank of FIG. 1;
FIG. 4 is a block diagram showing a configuration of a remaining amount monitoring device of the remaining amount management system in the storage tank of FIG. 1;
FIG. 5 is a flowchart illustrating an operation of a remaining amount monitoring device of the storage tank remaining amount management system of FIG. 1;
[Explanation of symbols]
Reference Signs List 1 storage tank 2 liquid level detector 3 remaining amount monitoring device 4 communication device 5 monitoring center 21 resistor 31 digital filter unit 32 volume calculating unit 33 memory unit 34 remaining amount calculating unit 35 alarm processing unit 36 display unit

Claims (2)

A storage tank (1) for containing and storing a liquid material therein;
A liquid level detector (2) for measuring a liquid level of the liquid material in the storage tank (1), and a volume remaining amount of the liquid material remaining in the storage tank (1) from the liquid level And a predetermined warning value can be set at the monitoring center (5) on the liquid material supply side via the communication device (4),
When the remaining volume of the liquid material becomes equal to or less than a predetermined warning value , a message signal is sent to a manager of the storage tank (1), and at the same time, a contact signal for turning on an alarm circuit and an open collector signal are sent. A warning is issued, and this warning is generated from an alarm processing device (35) on the manager side and notifies the monitoring center (5) via the communication device (4) to the manager on the storage tank (1). A remaining amount monitoring device (3), the remaining amount monitoring device (3) is configured to calculate the liquid material from the liquid level based on a relationship between a liquid level and a storage volume defined by an internal shape of the storage tank (1). Calculate the volume remaining of
The information on the volume remaining amount of liquid material, said communication device for communicating bidirectionally between the said residual amount monitoring device connected to the storage tank (1) and (3) the monitoring center (5) (4 ) And
The remaining amount management system in a storage tank, wherein the warning is notified to the monitoring center (5) via the communication device (4) . 2. The system according to claim 1, wherein the predetermined warning value can be set at the monitoring center (5) via the communication device (4).

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