JP3069914B2 - Fluid distribution method to heat absorbing wall in space environment test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention forms a high-vacuum and cryogenic environment which is almost equivalent to the space environment, and is used for testing various devices used in space such as artificial satellites. Related to space environment test equipment.

[Conventional technology]

In general, a space environment test apparatus (space chamber) simulates the darkness and darkness of the universe by installing a heat absorbing wall called a shroud or a shield inside a vacuum vessel, and evacuating the inside of the vacuum vessel with a vacuum pump. It simulates the high vacuum of the universe. That is, shroud 100K
It is common to simulate the darkness and darkness of the universe by cooling below, and liquid nitrogen has been mainly used as the cold source. Furthermore, in order to accommodate a specimen with a large amount of released gas in the vacuum container and to evacuate it to a high vacuum, it is necessary to evacuate using a very large pump. It was necessary to incorporate a cryogenic exhaust surface, that is, a cryopanel inside the shroud, to cool the cryopanel to 20K or less, and to function as a cryopump for condensing and exhausting gas such as nitrogen. Helium supplied from a helium refrigerator is conventionally used as a cooling source for the cryopanel.

In addition, when the inside of the vacuum vessel is heated to room temperature after the test is completed, it is generally performed by introducing nitrogen gas into the shroud.

In such a space environment test apparatus, a shroud or a cryopanel formed by joining a plurality of fin tubes to a collecting tube called a manifold is used.

[Problems to be solved by the invention]

However, when supplying a cold fluid such as liquid nitrogen or helium to a shroud using a large number of fin tubes, the heat load is the largest among the shrouds and the like.
The cold fluid was distributed to all the fin tubes according to the flow rate of the fin tubes requiring the largest amount of the cold fluid. In addition, even for fin tubes with different lengths, such as a disk-shaped shroud, other fins with a short length and low flow resistance are supplied because the cooling fluid is supplied according to the long fin tube with the largest heat load. An unnecessary amount of cold fluid was supplied to the tube, and an excessively large amount of cold fluid was used.

Therefore, an object of the present invention is to provide a fluid distribution method capable of supplying a cold fluid according to the heat load received by each fin tube and preventing the waste of the cold fluid.

[Means for solving the problem]

In order to achieve the above object, a method for distributing fluid to a heat absorbing wall in the space environment test apparatus of the present invention includes disposing a heat absorbing wall provided with a number of fin tubes inside a vacuum vessel,
A cold fluid is supplied to the fin tubes of the heat absorbing wall through a manifold, and when cooling the inside of the vacuum vessel, the flow rate of the cold fluid flowing into each fin tube at a junction between the manifold and the fin tubes is reduced. It is characterized in that flow rate adjusting means for controlling is provided.

〔Example〕

Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings.

First, as shown in FIGS. 3 and 4, a space environment test apparatus 1 according to this embodiment includes a body shroud 3 formed in a vacuum vessel 2 divided into a plurality of blocks and mirror shrouds at both ends of the vessel. 4 and each shroud 3,4
Is provided with an inlet manifold 5 and an outlet manifold 6 for introducing liquid nitrogen, respectively.
The inlet manifold 5 is located on the lower side of the device, and the outlet manifold 6 is located on the upper side.

As shown in FIG. 1, the shrouds 3 and 4 are formed by arranging a large number of fin tubes 7 integrally provided with wing sides on both sides of a tube without gaps. It is connected to the inlet manifold 5 or the outlet manifold 6 via rings 9 and 10.

Then, as shown in FIG. 2, both or one of the couplings 9 and 10, preferably the coupling 9 on the inlet manifold 5 side, is used to control the flow rate of the cold fluid flowing through the coupling 9. Orifice 11 is provided. The diameter of the orifice 11, that is, the flow rate is determined by the state of each fin tube 7. It is determined according to various conditions such as the mounting position of the pipe 7.

For example, in the case of the disk type shroud shown in FIG.
The diameter of the orifice 11 of the coupling 9 shows a distribution as shown in FIG. That is, a large amount of refrigerant is introduced into a fin tube located at the center and having a long length and a large surface area, and a small amount of refrigerant is introduced into a fin tube having a short end surface and a small surface area. Has been adjusted.

In order to determine the diameter of the orifice 11, for example, under the condition that the pressure losses between n adjacent fin tubes are equal, (n-1) simultaneous equations are established and Newton-Raphson is determined. The flow rate is determined by the method, and the cooling fluid can be supplied in a range obtained by adding about 5% to 20% to the required flow rate.

As the flow rate adjusting means, in addition to providing the orifice 11 in the coupling 9 as described above, simply inserting an orifice into the fin tube 7, and changing the diameter and length of the vent pipe to have a flow rate adjusting function. This can be performed by various means such as changing the diameter of the connection port of the manifold.

Further, for the detailed structure of the shroud and the like, an optimal shape and combination can be appropriately selected depending on the size of the vacuum vessel, the number of divided shrouds and the like.

〔The invention's effect〕

As described above, in the method of distributing fluid to the heat absorbing wall in the space environment test apparatus of the present invention, the optimum flow rate can be set according to the heat load and the flow path resistance of the heat absorbing wall. The capacity of the liquid supply equipment can be reduced, the size of the refrigerator equipment can be reduced, and energy consumption can be reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a side view showing a connection state of a fin tube, FIG. 2 is an enlarged sectional view of a connection portion of the fin tube, and FIG. FIG. 4 is a front view of a disk-shaped shroud, and FIG. 5 is a view showing a diameter distribution of an orifice. DESCRIPTION OF SYMBOLS 1 ... Space environment test apparatus, 2 ... Vacuum container, 3 ... Trunk shroud, 4 ... Mirror shroud, 5 ... Inlet manifold, 6 ... Outlet manifold, 7 ... Fin tube, 8
…… vent pipe, 9,10 …… coupling, 11 …… orifice

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B64G 7/00

Claims (1)

(57) [Claims] A heat absorbing wall provided with a number of fin tubes arranged inside a vacuum vessel, a cooling fluid is supplied to the fin tubes of the heat absorbing wall through a manifold, and the inside of the vacuum vessel is cooled. A flow control means for controlling a flow rate of a cold fluid flowing into each of the fin tubes at a joint portion between the manifold and the fin tubes. Method.