JPH04204029A - Leakd detector - Google Patents

Abstract

PURPOSE:To obtain a system which gives a warning only when a piping leaks by providing an automatic leaking object judging apparatus comprised of a liquid temperature sensor, a humidity sensor and a humidity sensor of the outside air. CONSTITUTION:The surface temperature of a process piping is measured by a piping surface temperature thermometer 2 which outputs a piping surface temperature signal 7. The humidity of tone piping atmosphere is detected by an outside air humidity sensor 3 which generates an outside air humidity signal 8. The moisture content from the process piping is measured by a moisture sensor 4, and a moisture signal 9 is output. A leaking object judging part 5 having inputs of the signals 7, 8, 9 judges whether or not the moisture resulting from the leak is detected, and outputs a warning signal 10 to a warning circuit 6. Accordingly, an erroneous generation of warning due to the dew formed in the piping can be prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a fluid leak detection device in piping.

[Conventional technology]

Conventional devices, as described in Japanese Patent Application No. 62-273059, detect moisture using a humidity sensor and issue an alarm in the event of a leak.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, a humidity sensor is installed at a location where leakage is expected, and a leak is detected when humidity (water droplets) is detected.

On the other hand, the causes of water droplets from piping include not only leakage of piping, but also when the atmosphere is humid and the fluid is low temperature, the piping is cooled by the fluid, the outside air on the piping surface reaches the dew point, and condensation occurs. may form water droplets.

Therefore, in the prior art, there was a problem in that even if water droplets were generated due to any of the above factors, the pressure would be detected as a leak.

An object of the present invention is to provide a system configuration that generates an alarm only when there is leakage from piping.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an automatic leakage determination device consisting of a fluid temperature/humidity sensor and an outside air humidity sensor, outputs the determination result to an alarm circuit, and issues an alarm only when fluid leaks.

(Function) The automatic leak detection device uses a pipe surface thermometer, an outside air hygrometer,
The piping surface thermometer, which is composed of a moisture sensor and a leak detection section, measures the surface temperature of the piping at the position where leakage is expected.

The outside air hygrometer measures the humidity of the pipe atmosphere.

The moisture sensor measures moisture (water droplets) from the pipes.

The leakage determining unit inputs the measured value as described above, determines the cause of moisture (water droplet) detection, and outputs an output to the alarm circuit only in the case of leakage. The determination method is to calculate the dew point temperature of the atmosphere from the outside air humidity, and if the moisture sensor detects moisture when the pipe surface temperature is above the dew point, an alarm is output. If the pipe surface temperature is below the dew point, if the moisture detection interval is short,
Outputs a warning. The interval of this moisture detection is automatically changed depending on the outside air humidity and the pipe surface temperature.

This prevents false alarms from occurring when moisture is detected due to condensation.

〔Example〕

FIG. 1 shows an embodiment of the present invention. The surface temperature of the process pipe 1 is measured by a pipe surface thermometer 2, and a pipe surface temperature signal 7 is output. The humidity of the pipe atmosphere is measured by an outside air hygrometer 3, and an outside air humidity signal 8 is output. Moisture generated from the process piping is measured by a moisture sensor 4 and a moisture signal 9 is output. The leakage determination unit 5 receives a piping surface temperature signal 7. Outside air humidity signal 8. A moisture signal 9 is input, it is determined whether moisture is detected due to leakage, and an alarm signal 10 is output to the alarm circuit 6.

FIG. 2 shows a processing flow of the leaked substance determining section 5.

Dew point temperature 11 is calculated from the outside air humidity signal. The dew point temperature 5 is compared with the pipe surface temperature 7, and if the pipe surface temperature is higher than the dew point temperature, it is determined that no condensation has occurred. If the pipe surface temperature is lower than the dew point temperature, it is determined that condensation has occurred, and a moisture detection interval judgment value is calculated. In the moisture detection interval judgment value calculation, in order to judge whether the cause of moisture detection is dew condensation or leakage at the moisture inspection interval, the judgment value is calculated from the pipe surface temperature and the dew point temperature. In the alarm determination section, when the moisture signal 9 is received, if the condensation non-occurrence condition is satisfied,
An alarm signal 10 is output. When condensation occurs, the moisture detection interval is measured and compared with the moisture detection interval judgment value calculated above. If the measured value is shorter than the judgment value, it is determined that there is a leak and an alarm signal 10 is output. If the measured value is longer than the judgment value, it is determined that there is condensation and no alarm is output.

〔Effect of the invention〕

According to the present invention, in a circuit that uses a moisture sensor to detect leakage from piping and generates an alarm, it is possible to prevent false alarms from occurring due to dew condensation on the piping.

[Brief explanation of the drawing]

FIG. 1 is an instrumentation system diagram according to an embodiment of the present invention, and FIG. 2 is a diagram showing a processing flow of a leakage material determining section according to an embodiment of the present invention. 1... Process piping, 2... Piping surface thermometer, 3.
...Outside air hygrometer, 4...Moisture sensor, 5...Leakage determination unit. Figure 1

Claims (1)

[Claims] 1. A device for detecting fluid leakage using a humidity sensor, characterized by having a function of automatically determining the cause of moisture detection by inputting fluid temperature and outside air humidity. Leak detection equipment.