JPH023162Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a thermal testing device for high temperature gas. For example, helium gas is used as a heat carrier at temperatures as high as several hundred degrees.

When testing the properties of such gases under pressure and high temperatures, it is best to separate the equipment that heats the gas and the test section, and connect them with piping, which increases the size and complexity of the equipment. It is common to avoid.
However, since high-temperature gas is transferred through piping, the temperature may drop due to heat loss during transfer. When the gas flow rate is large, this temperature drop does not pose much of a problem, but when the gas flow rate is small, it becomes large and requires some kind of treatment. This is because, due to its nature as a testing section, the temperature of that section must bring the flow rate under predetermined conditions.

Therefore, it is necessary to provide assistance (compensation) near the entrance of the testing section.
It is necessary to install a heater for heating.

However, pipe heaters tend to be expensive, and external heaters tend to be complicated and expensive. It was proposed that a heating wire be wrapped around the outside of the cylinder, and the gas would flow through a circular cross-sectional flow path inside the cylinder.

The above-mentioned cylindrical heater copes with the temperature drop during low gas flow rates, but when gases such as helium are heated at low flow rates, the heat removal ability (heat transfer coefficient) decreases ( A problem arises in that the laminar flow phenomenon is likely to occur, particularly in a circular cross-sectional flow path, and the following disadvantages arise.

(a) Because the heater is installed far from the desired temperature setting, there is a lot of heat dissipation along the way.

(a) At low flow rates, the target gas convects only around the heater surface, and low-temperature fluid is pushed downwards in the center.

(c) At low flow rates, the heater surface is not cooled smoothly by the target gas, so the temperature of the heater surface rises quickly. As a result, the heater itself overheats.

The present invention has been developed in view of the above-mentioned circumstances.

That is, in the present invention, a heating connecting tube having an annular cross-sectional flow path and a thermal expansion difference absorbing structure is installed inside a container surrounding the test specimen section, and the connecting tube is connected between the test specimen section and the inlet pipe of the container. The test material is interposed between the test specimen and the test specimen to suppress the occurrence of laminar flow phenomenon at low flow rates, and to suitably set the temperature of the gas supplied to the test specimen from low flow rates to high flow rates. The aim is to provide the equipment.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

In FIG. 1, a test specimen section 13 is formed inside a pressure vessel 10, and an inlet section 15 that projects upward is provided. An inlet pipe 17 extending through the upper part of the body of the container 10 communicates with a source of heating gas, i.e., high-temperature helium gas (not shown), and is closed at its inner end and provided with an opening 19 of circular cross section at the side. There is.

An enlarged upper end portion of a heating connecting tube, that is, a heater 21, which is connected and fixed to the side of the inlet portion 15 and extends vertically upward, is inserted into the opening 19, and a seal ring 23 is fitted therebetween. The ring 23, which is axially displaced together with the heater 21, slides on the inner surface of the opening 19 and absorbs the difference in thermal expansion while preventing gas leakage.

Although not shown in FIG. 1, a heat insulating material is attached to the inner surface of the pressure vessel 10.

FIG. 2 shows a cross section of the heater 21.
A heat insulating material 29 is filled between the outer tube 25 and the inner tube 27, and six sheathed heaters 31 are provided in contact with the outer surface of the inner tube 27.

Further, a sheathed heater 33 is coaxially provided at the center of the inner tube 27, and an annular flow path 35 for helium gas is formed in the inner tube 27.

In such embodiments, hot helium gas from the source enters the inlet pipe 17 with a temperature drop due to heat loss in a transfer line (not shown);
Furthermore, it enters the heater 21.

Since the amount of temperature decrease is almost determined by the flow rate value, the necessary electric power is applied to the sheathed heaters 31 and 33 in consideration of the flow rate value and the set value of the test specimen part,
The helium gas is compensated and heated to a set temperature (if necessary, a feedback circuit is provided).

The helium gas at the set temperature then flows into the test body section 13 and is subjected to various tests.

According to the embodiment described above, the helium gas flow path of the heater 21 has an annular cross section, and the sheathed heaters are arranged at the center and outer periphery of the flow path, so that no laminar flow phenomenon occurs even at low flow rates. , the gas is efficiently heated and the helium gas can be brought to the set temperature over a wide flow rate range.

Furthermore, since heat transfer from the sheathed heaters 31, 33 to the gas is performed well, extremely excellent practical effects such as no burnout of the sheathed heaters 31, 33 due to overheating are achieved.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing an embodiment of the present invention;
The figure is a sectional view taken along the - line in FIG. 1. 10... Container, 21... Heater, 31, 33...
...Sheathed heater, 35...Annular flow path.

Claims (1)

[Scope of utility model registration request] A container with a heat insulating material attached to the inner surface, a test body part provided inside the container and defining a test space inside, and a gas container provided by penetrating the body of the container at right angles and having an opening on the side of the tip. It has an inlet pipe and a heating connecting pipe whose one end is fixed to the test body part and whose other end is slidably fitted into the opening, and a sheathed heater is arranged at the center and outer periphery of the flow path of the connecting pipe. This is a thermal testing device for high-temperature gas.