JPH0727591A - Method for estimating gas pipe capacity - Google Patents

Abstract

PURPOSE:To simply estimate the pipe capacity in a specific zone in a short time by arranging a supply gas pressure fluctuating device most upstream the estimation object zone, actively changing the gas pressure at a fixed time interval, and measuring the fluctuation patterns of pressure and flow. CONSTITUTION:A pipe capacity estimating device 6 drives a supply gas pressure fluctuating device 3 to fluctuate the supply gas pressure at a fixed time interval. A pressure measuring device 4 and a flow measuring device 5 measure the fluctuations of pressure and flow in an estimation object zone 1 and output them to the estimating device 6. The estimating device 6 estimates the total capacity in the estimation object zone 1 based on the fluctuations of pressure and flow measured by the device 4 and the device 5. The fluctuations are small when the object zone 1 is short, and the fluctuations are made larger as the object zone 1 becomes longer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for estimating the capacity of a buried gas pipe for supplying city gas.

[0002]

2. Description of the Related Art The capacity of a gas pipe can be measured by knowing the length of a measuring section and the sectional area of the pipe.

[0003]

However, in the above measuring method, the length and diameter of the pipe must be measured each time before the calculation can be performed. Therefore, it takes a lot of time and labor before the measurement. Therefore, for example, when determining a gas leak from a gas supply pipe, it is conventionally determined from a change in gas pressure or a change in flow rate. It becomes possible to make a more accurate determination of gas leakage according to the situation, but this is not possible because the pipe capacity cannot be known in a short time.

An object of the present invention is to propose a method for estimating the pipe capacity in a specific section simply and in a short time.

[0005]

The method of estimating the gas pipe capacity according to the present invention is as follows.

A supply gas pressure fluctuation device is attached to the upstream side of the governor-equipped gas appliance and at the most upstream part of the capacity estimation target section, and a pipe gas pressure measurement device and flow rate measurement device are provided downstream of this supply gas pressure fluctuation device. Attach the device, apply pressure fluctuations with the supply gas pressure fluctuation device while using gas appliances, measure the pressure and flow rate when this pressure fluctuation is applied with the pressure measuring device and flow rate measuring device, and measure the measured pressure and flow rate. A method of estimating the total capacity in the capacity estimation target section from the fluctuation pattern.

[0007]

Operation: The supply gas pressure fluctuation device is attached to the most upstream part of the estimation target section. In addition, a gas instrument with a governor is attached to the terminal of the estimation target section so that the gas pressure becomes constant (combustion becomes constant), and this gas instrument is in use at the time of measurement. There is a condition.

In the estimation, the supply gas pressure fluctuation device such as a governor is operated to actively change the supply gas pressure at regular time intervals. In this way, pressure fluctuations and flow rate fluctuations occur in the estimation target section. The fluctuation range of the flow rate is small when the estimation target section is short, and increases as the estimation target section becomes long. The pipe capacity is estimated from this pressure and flow rate fluctuation pattern.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a method for estimating a gas pipe capacity according to the present invention, 1 is an estimation target section, 2 is a gas appliance with a governor attached to a terminal, and 3 is a supply gas pressure fluctuation device. 4 is a pressure measuring device attached to the estimation target section 1, 5 is a flow rate measuring device, and 6 is a pipe capacity estimating device.

At the time of estimation, the pipe capacity estimating device 6 drives the supply gas pressure changing device 3 to change the supply gas pressure at constant time intervals. The pressure measuring device 4 and the flow rate measuring device 5 measure the fluctuation of the pressure and the fluctuation of the flow rate in the estimation target section 1 at the time of the pressure fluctuation. Pipe capacity calculation device 6
Estimates the total capacity in the estimation target section 1 from the measured values measured by the pressure measuring device 4 and the flow measuring device 5.

FIG. 2 shows an example of the fluctuation of the pressure measured by the pressure measuring device 4 when the supply gas pressure fluctuation device 3 fluctuates the pressure. In the case of the embodiment, the fluctuation of the pressure is measured at intervals of 10 seconds. Is going. FIGS. 3, 4, and 5 show changes in the flow rate due to this pressure change converted into pulses.
Indicates a case where the estimation target section 1 is short, FIG. 4 is a little long, and FIG. 5 is a very long. As is clear from FIGS. 3 to 5, the flow rate fluctuation is small when the estimation target section is short, and increases as it increases.

[0012]

As described above, according to the present invention, the capacity of the gas supply pipe can be estimated by a simple method. Therefore, in the method of inspecting the gas leakage by actively causing the pressure fluctuation of the supply gas, information can be obtained. As a result, a highly accurate inspection result can be quickly obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an example of pressure fluctuation obtained by driving a supply gas pressure fluctuation device.

FIG. 3 is an explanatory diagram of flow rate fluctuation when the pipe length is short.

FIG. 4 is an explanatory diagram of flow rate fluctuation when the pipe length is slightly long.

FIG. 5 is an explanatory diagram of flow rate fluctuation when the pipe length is extremely long.

[Explanation of symbols]

 1 estimation target section 2 gas appliance 3 supply gas pressure fluctuation device 4 pressure measurement device 5 flow rate measurement device 6 pipe capacity calculation device

Claims (1)

[Claims] 1. An upstream side from a gas appliance with a governor,
A supply gas pressure fluctuation device is attached to the most upstream part of the capacity estimation target section, and a pipe gas pressure measurement device and a flow rate measurement device are installed downstream of this supply gas pressure fluctuation device,
Pressure fluctuation is applied by the supply gas pressure fluctuation device while the gas appliance is in use, and the pressure and flow rate when this pressure fluctuation is applied are measured by the pressure measuring device and flow rate measuring device, and the capacity is calculated from the fluctuation pattern of the measured pressure and flow rate. A method to estimate the total capacity in the estimation target section.