JP2547710Y2 - Low temperature liquefied gas truck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a low-temperature liquefied gas lorry vehicle for transporting a low-temperature liquefied gas such as liquefied nitrogen, liquefied oxygen, liquefied argon and the like.

[Conventional technology]

The low-temperature liquefied gas is used in various industrial fields, but is usually supplied and consumed by customers using a low-temperature liquefied gas lorry equipped with a low-temperature liquefied gas storage tank (hereinafter referred to as a lorry). .

FIG. 2 is an explanatory view showing a conventional low-temperature liquefied gas distribution route, and 1 is a lorry vehicle. In order to supply the low-temperature liquefied gas to the customer, first, the lorry vehicle 1 is moved to the low-temperature liquefied gas manufacturing plant A, and the low-temperature liquefied gas produced in the plant A is cooled by the low-temperature liquefied gas loaded on the loading platform of the lorry vehicle 1. The gas is filled in a gas storage tank (hereinafter referred to as a storage tank) 2. Next, the lorry 1 goes to a weighing station B equipped with a weighing scale (truck scale) capable of measuring the weight of the lorry 1 and measures the total weight including the body weight. Next, the lorry vehicle 1 goes to the location of the first customer C, fills the storage tank C1 provided therein with the low-temperature liquefied gas, returns to the weighing station B again, and measures the total weight again. Then, the difference between the total weight before and after the supply of the low-temperature liquefied gas to the first customer C is dealt with as the supply amount of the low-temperature liquefied gas to the first customer C.

When continuously supplying the low-temperature liquefied gas to the second customer D, if there is a sufficient amount of the low-temperature liquefied gas remaining in the storage tank 2 of the lorry vehicle 1, go directly to the location of the second customer D as it is, After supplying the low-temperature liquefied gas to the storage tank D2 of the customer D, the process returns to the weighing station B, and the difference between the total weight before and after the low-temperature liquefied gas is supplied is defined as the low-temperature liquefied gas supply amount to the second customer D in the same manner as described above. Make a deal. When the amount of the remaining low-temperature liquefied gas in the storage tank 2 of the lorry vehicle 1 is not sufficient, the process returns to the low-temperature liquefied gas manufacturing factory, and the low-temperature liquefied gas is supplied to the second customer D in the same manner as the first customer C. Supply.

[Problems to be solved by the invention]

However, according to the transaction method, since the transaction volume is calculated each time the low-temperature liquefied gas is supplied, it is necessary to return to the weighing station B for each transaction, for example, the first customer C and the second customer D
Is near, and even if the lorry car 1 can continuously supply the low-temperature liquefied gas to both customers, since it is a different customer,
There was a disadvantage that every time the low-temperature liquefied gas was supplied, it was necessary to return to the weighing station and calculate the transaction volume. In addition, even if multiple storage tanks in the vicinity are of the same customer, different accounts are often used if the department in charge at the customer is different. The fact is that they return to the weighing station every time to calculate.

A liquid level gauge is provided in the storage tank of the customer, and this liquid level gauge is effective as a means for knowing the outline of the residual amount of the low-temperature liquefied gas in the storage tank, but is used for trading. Is not usable in terms of accuracy.

Therefore, the present inventors conducted intensive research in front of the customer to develop a lorry vehicle capable of calculating a low-temperature liquefied gas supply amount.

Here, when a general flow meter is simply used, for example, when a general volume flow meter that measures the flow rate by rotating a metering chamber having a constant volume is used, when the supply to the customer storage tank is completed, a low temperature is used. Liquefied gas is extremely dangerous because it is sealed in the measuring chamber.Because it has mechanically movable parts, it will break down in a relatively short time due to vibration when it is loaded on a transport device such as a lorry, and it will not withstand practical use at all. Turned out not to be.

Therefore, an orifice flow meter was also studied as a flow meter which does not become a closed state after filling the low-temperature liquefied gas and has no mechanically movable parts. However, in the orifice flow meter, it is necessary to provide a conduit for taking out the differential pressure before and after the orifice plate to take out the differential pressure before and after the orifice when the fluid passes. Although it is necessary to be filled with liquefied gas, the low-temperature liquefied gas is easy to evaporate at an extremely low temperature close to minus 200 ° C, and because it is a closed space in the conduit, it is easy to evaporate and accurate measurement is difficult, It was not possible to obtain the same measured values as the conventional method using a weighing station. In addition, if sufficient cooling measures are taken around the conduit to prevent evaporation in the conduit, the overall volume increases and it is virtually impossible to load in a narrow space like a lorry. is there.

That is, it was found that a satisfactory result could not be obtained by using a conventional general flow meter.

Therefore, as a result of various studies, we examined the measurement of flow rate using a Kalman flow sensor. This Kalman flow sensor does not have a structure for sealing a low-temperature liquefied gas and has no mechanical movable parts, so it is resistant to vibration and can be suitably used for a transportation means such as a lorry.

However, it is difficult to accurately measure the amount of low-temperature liquefied gas supplied from a lorry vehicle, unlike the case where low-temperature liquefied gas is supplied from a fixed storage tank installed on the ground simply by simply using a Kalman flow sensor. It is.
The reason is that during the supply of the low-temperature liquefied gas, the temperature of the low-temperature liquefied gas in the tank of the lorry vehicle rises significantly compared with that of the low-temperature liquefied gas in the stationary storage tank.
This is because the temperature rises by about ℃ and the density of the low-temperature liquefied gas changes.

The cause of such a large temperature rise is that the tank of the lorry is not large enough to supply the low-temperature liquefied gas to the customer at one time. Since the liquefied gas is often led out, the pressurized evaporator is frequently operated to maintain the pressure in the storage tank, whereby the heat of the atmosphere is introduced into the storage tank via the pressurized evaporator, and the low-temperature liquefaction is performed. This is because the temperature of the gas increases significantly. On the other hand, the supply of low-temperature liquefied gas from a stationary tank (normally several tens of times larger than that of a lorry vehicle) is usually several percent of the total capacity of the stationary tank, The temperature rise of the low-temperature liquefied gas is 1 ° C. or less, and there is almost no need to consider the temperature rise. Although the density of the low-temperature liquefied gas changes depending on the pressure, the change in the density with respect to the pressure is very small, and the effect of the pressure can be ignored at a normal supply pressure (3 to 15 kg / cm ² ).

Therefore, the present inventor pays attention to the use mode of the lorry vehicle and the behavior of the low-temperature liquefied gas as described above, and corrects the temperature of the flow rate data obtained by the Kalman type flow sensor by the temperature correction so that the temperature is low enough to withstand the transaction. It has been found that the liquefied gas supply can be measured with high accuracy.

[Means for solving the problem]

The low-temperature liquefied gas lorry vehicle according to the present invention is based on the above findings.In a low-temperature liquefied gas lorry vehicle equipped with a low-temperature liquefied gas storage tank, the low-temperature liquefied gas discharge pipe connected to the low-temperature liquefied gas storage tank has Karman. Integral calculation for providing a low-temperature liquefied gas supply amount by providing a flow rate sensor and a temperature sensor, receiving signals from both sensors, and correcting the flow rate signal from the Kalman flow rate sensor with the temperature signal from the temperature sensor. A container is provided.

[Action]

The Kalman type flow sensor has a rod-shaped object erected at the center of a flow and measures the flow rate based on the number of vortices (Karman vortices) formed in the fluid after passing through the rod-shaped object. The low-temperature liquefied gas supplied to the storage tank at the customer is measured by a Kalman flow sensor provided in the low-temperature liquefied gas discharge pipe connected to the storage tank of the lorry vehicle, and provided in the low-temperature liquefied gas discharge pipe. The temperature is measured by the temperature sensor, and the flow rate and temperature data measured by the two sensors are introduced into an integrating calculator to correct the temperature, and the supply amount of the low-temperature liquefied gas is accurately calculated.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

FIG. 1 is an explanatory view showing a state in which low-temperature liquefied gas is being supplied from a storage tank 10 of a lorry vehicle according to the present invention to a storage tank C1 of a customer, and a liquid outlet valve 11 is provided at the bottom of the storage tank 10 of the lorry vehicle. A low-temperature liquefied gas outlet pipe 12 is provided in series, and a Kalman flow rate sensor 13 and a temperature sensor 14 are provided in the middle of the outlet pipe 12, and a blow valve 15 is provided near the end of the outlet pipe 12.

The Kalman flow sensor 13 and the temperature sensor 14 are connected to an integrating calculator 17 via signal lines 16 and 16, respectively, and the calculator 17 receives signals from both the sensors 13 and 14 and receives the Kalman flow sensor. The flow rate signal obtained from 13 is temperature-corrected with the temperature signal obtained from temperature sensor 14 to calculate the low-temperature liquefied gas supply amount. Further, a printing device 18 is connected to the integrating calculator 17. The printing unit 18 prints data necessary for the transaction, such as the supply date, the vehicle number of the lorry, and the like, in addition to the amount of the low-temperature liquefied gas supplied to the customer. In the figure, the temperature sensor 14 is the Kalman type flow sensor 13
Although provided on the secondary side, since the temperature of the low-temperature liquefied gas flowing through the low-temperature liquefied gas outlet pipe 12 is the same, it may be provided on the primary side of the Kalman type flow sensor 13.

In addition, a pressurizing evaporator 20 and a pressurizing source valve 21 are provided in a pressurizing pipe 19 that connects the bottom part and the upper part (gas phase part) of the storage tank 10 continuously.
Although not shown, the storage tank 10 is provided with equipment such as a safety valve that discharges the internal low-temperature liquefied gas to the outside when the pressure in the storage tank 10 exceeds a predetermined value.

The procedure for supplying low-temperature liquefied gas to the customer storage tank C1 using the lorry vehicle of the present invention configured as described above will be described.
Although not shown, the customer storage tank C1 is also provided with a blow valve, a safety valve, and the like.

First, the end of the low-temperature liquefied gas outlet pipe 12 and the liquid receiving end of the customer storage tank C1 are connected by a flexible charge pipe 22. Next, the inside of the low-temperature liquefied gas outlet pipe 12 is cooled by operating the liquid outlet valve 11 and the blow valve 15 in the opening direction.

When the inside of the low temperature liquefied gas outlet pipe 12 is cooled to a predetermined temperature, the blow valve 15 is operated in the closing direction and the liquid receiving valve C2 of the customer is operated in the opening direction to supply the low temperature liquefied gas. During the supply, the pressure source valve 21 is adjusted to a predetermined opening,
Prevents pressure drop due to decrease of low temperature liquefied gas inside. When the pressurization source valve 21 is opened, the low-temperature liquefied gas at the bottom of the storage tank 10 is introduced into the pressurized evaporator 20 and receives the heat of the atmosphere to evaporate and expand.
It is introduced into the upper part of the storage tank 10 to increase the pressure in the storage tank 10. The vaporized gas introduced into the upper part (gas phase part) of the storage tank 10 is:
It contacts the low-temperature liquefied gas in the storage tank 10 and partially reliquefies,
Thereby, the temperature of the low-temperature liquefied gas itself in the storage tank 10 also rises.

Next, when an appropriate amount of low-temperature liquefied gas is introduced into the customer storage tank C1, the supply is stopped by operating the liquid outlet valve 11 and the customer liquid receiving valve C2 in the closing direction, and the blow valve 15 is opened. The low-temperature liquefied gas remaining in the low-temperature liquefied gas outlet pipe 12 is released to the atmosphere, and the supply is terminated.

By the above operation, the low-temperature liquefied gas is supplied to the customer storage tank C1, and the supply amount during this time is determined by the integrating calculator 17 which receives signals from the Kalman flow sensor 13 and the temperature sensor 14.
The temperature is corrected to calculate the low-temperature liquefied gas supply amount, the supply amount is printed from the printer 18, and the supply amount can be traded in front of the customer.

Next, when a low-temperature liquefied gas (liquefied nitrogen) is supplied using a 9-ton lorry truck (maximum loading capacity 8600 l, vehicle weight about 10 tons) to which the present invention is applied, the low-temperature liquefied gas supply amount of the integrating calculator 17 An experiment was performed to compare the calculated value with the calculated value of the low-temperature liquefied gas supply amount obtained using a conventional weighing station (using a 20-ton truck scale).

In this experiment, low-temperature liquefied gas was supplied to three different customers A, B, and C using the same lorry vehicle. The calculated value (Nkg) using the location, the difference between the two values (M-Nkg), and the ratio of the difference to the calculated value of the weighing station ((MN) / N%) were determined. Table 1 shows the results.

As is evident from Table 1, the ratio of the difference between the calculated value according to the present invention and the calculated value using a weighing station is 0.
It is 5% or less, and if the difference is about this level, it can be regarded as the same amount as that of the conventional method, so that it can be sufficiently used for trading. In the above experimental example,
The supply time to the customer A is 40 minutes, the temperature rise of the low-temperature liquefied gas before and after the supply is 5 ° C., and for the customer B is 30 minutes 4.
The temperature was 5 ° C., and the temperature of the customer C was 3 ° C. in 20 minutes. Also, as is clear from Table 1, it can be seen that the error rate decreases as the amount of supply to the customer increases.

In the above embodiment, the low-pressure liquefied gas is supplied by the pressure of the storage tank of the lorry vehicle. However, the low-pressure liquefied gas supply pipe is provided with a low-temperature liquefied gas supply pump. The same can be applied to the case of the supply system.

[Effect of the invention]

As described above, the lorry vehicle of the present invention measures the amount of liquefied liquefied gas supplied to the customer using the Kalman flow sensor, measures the temperature of the supplied liquefied liquefied gas with the temperature sensor, and performs integration calculation. The low-temperature liquefied gas supply to the customer can be calculated according to the lorry vehicle of the present invention because the temperature of the low-temperature liquefied gas supply can be calculated accurately enough to make a transaction with the customer by correcting the temperature with a vessel. The amount can be easily measured with almost the same accuracy as the conventional low-temperature liquefied gas supply amount calculation method that reciprocates between the weighing station and the customer, and can be traded in front of the customer after the supply. Therefore, compared to the conventional supply method, the flow form of the low-temperature liquefied gas can be greatly improved, the economic efficiency can be improved, and the effect of the implementation is extremely large.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, in which a low-temperature liquefied gas is supplied from a lorry storage tank to a customer storage tank, and FIG. 2 is a conventional low-temperature liquefied gas distribution. It is explanatory drawing which shows a route. 10 ... storage tank, 11 ... liquid outlet valve, 12 ... low temperature liquefied gas outlet pipe, 13
... Kalman flow sensor, 14 ... Temperature sensor, 15 ... Blow valve, 16 ... Signal line, 17 ... Integration calculator, 18 ... Printer, 20 ... Pressurized evaporator, 22 ... Charge pipe, C1 ... Customer storage tank

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Katsumi Yamagaki 4-320 Tsukagoshi, Saiwai-ku, Kawasaki-shi, Kanagawa Japan Oxygen Corporation (56) References JP-A-52-92745 (JP, A) JP-A-54- 11766 (JP, A) Jiko 40-11457 (JP, Y1)

Claims (1)

(57) [Scope of request for utility model registration] 1. A low-temperature liquefied gas lorry equipped with a low-temperature liquefied gas storage tank, wherein a low-temperature liquefied gas outlet pipe connected to the low-temperature liquefied gas storage tank is provided with a Kalman-type flow sensor and a temperature sensor. A low temperature liquefied gas lorry vehicle comprising an integrating calculator for calculating the low temperature liquefied gas supply amount by temperature-correcting the flow signal from the Kalman flow sensor in response to the temperature signal from the temperature sensor.