JPS5836695B2 - Ground freezing prevention device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a ground freezing prevention device.

The object of the present invention is to provide a device that prevents freezing of the ground surrounding a liquefied gas storage underground tank and freezing of water inside a bit or the like provided in the ground.

Generally, the ground surrounding liquefied gas storage underground tanks cannot avoid freezing due to the extremely low temperature of the liquefied gas, and this freezing expansion pressure has caused problems such as pressure being applied to the tank body and surrounding structures.

This invention was developed to address the above-mentioned conventional problems, and uses a steam circulating hot water heater buried underground to prevent the ground from freezing and the water inside the bits installed in the ground from freezing. This is what I am trying to do.

The present invention will be described below based on an embodiment shown in the drawings. An inner pipe 2 for supplying steam is disposed inside an outer pipe 1 buried in the ground or at a predetermined position in a bit.
The injector 3 is located at the upper part of the outer tube 1.

The inner pipe 2 is also provided with an automatic temperature control valve near the steam supply port.

The injector 3 is provided with a heat insulating part 4 around the injector, but this heat insulating part 4 can be obtained by providing an air layer, a vacuum layer, etc. in addition to using a heat insulating material such as pearlite particles, and only a part of the injector is provided. Instead, it may be provided near the injector or over the entire length of the inner tube 2.

The outer tube 1 is filled with warm water, and the upper part of the outer tube 1 is provided with a discharge port 5 for discharging excess water.

In the antifreeze device having the above configuration, the steam supplied from the steam supply device (not shown) sucks the hot water in the outer tube 1 when passing through the injector 3.
The hot water reaches the lower end of the inner tube 2 while being heated and rises inside the outer tube 1 due to the circulation action of the injector 3, and excess hot water that is not drawn into the injector 3 is discharged through the drain port 5.

The steam is condensed by the injector 3 to lower the inlet temperature, and since the hot water is constantly circulated, the internal hot water temperature is relatively uniform in the vertical direction.

If the diameter of the inner tube 2 is made smaller, the amount of heat transferred in the lateral direction becomes smaller, so that the internal hot water temperature becomes more uniform.

When the amount of steam increases, the amount of hot water circulated also increases, so the difference between the top and bottom of the hot water temperature can be kept small.

Therefore, even when the amount of external heat transfer changes, that is, even when the steam flow rate changes, the temperature difference in the vertical direction can be kept small.

In this device, hot water is circulated by an injector based on steam pressure.
It does not require power equipment such as pumps, and has a simple structure, so there are fewer parts to break down.

Furthermore, since the functional parts such as the injector are located at the top, maintenance is easy.

It is also possible to detect the internal fluid temperature using the temperature detection and transmitter 7 and automatically adjust the temperature using the automatic temperature control valve 6 or the like.

This automatic temperature control valve may be installed for each system.

The on-site assembly of this device is very simple as it only involves connecting the piping.

In this device, the latent heat of the steam is fully used, so running costs are low.

As mentioned above, in this device, the temperature distribution inside the outer tube 1 is relatively uniform, so it is possible to uniformly heat the surrounding ground where this device is buried or the surrounding water, preventing it from freezing. It can be prevented.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view showing an embodiment of the present invention. 1... Outer pipe, 2... Inner pipe, 3...
...Injector, 4...Insulation section, 5...
...Drain port, 6...Automatic temperature control valve, 7...
...Temperature detection and transmitter, 8...Drainage ditch.

Claims (1)

[Claims] 1. In an outer pipe buried in the ground and filled with hot water, an inner pipe communicating with the steam supply pipe is arranged from the upper end to the lower part of the outer pipe, and the vicinity of the upper end inside the outer pipe of the inner pipe is used as an injector, A ground freezing prevention device characterized in that said part is covered with a heat insulating part, and a drainage port is provided in the upper part of said outer pipe.