RU231536U1 - Inert chamber with passive cooling system - Google Patents

Abstract

The utility model relates to an inert chamber and is used in pyrochemical processing technologies. The device comprises a double-walled capsule, a lock door, a heat exchanger, wherein the heat exchanger is located on the inner surface of the side walls of the double-walled capsule and is separated from the inner space of the double-walled capsule by a guide partition. The partition is installed in such a way that gaps are formed between the edges of the partition and the inner surfaces of the upper and lower walls of the double-walled capsule. The technical result is increased reliability. 6 fig.

Description

The utility model relates to inert chambers and is used in pyrochemical processing technologies.

Pyrochemical processing is a stage of the closed nuclear fuel cycle technology aimed at processing spent nuclear fuel (SNF). The main objective of pyrochemical processing is to reduce the SNF holding time before processing in order to launch valuable components into the nuclear fuel cycle as quickly as possible, as well as to reduce the total amount of fissile materials present in it. Inert chambers are used to implement the pyrochemical process. As a rule, this is a closed double-walled shell, in the internal and interwall volume of which argon is located. The main requirement for the chamber, in addition to tightness, is to ensure the removal of heat emitted by the processed product and maintain the temperatures of the shells and process equipment inside the chamber within acceptable limits.

The closest analogue is an inert chamber with five cooling units, presented in the form of a double-walled capsule with an inert environment and vacuum pressure, a lock door located in the end part of the double-walled capsule, in the upper part of the double-walled capsule there are rails along which the manipulator moves. Four cooling units are installed along the long side wall and one more is installed on the end wall. The cooling units consist of a housing attached to the wall of the double-walled capsule, in the lower part there is an opening for air suction, in the cross section of which a heat exchanger is installed. The coolant is ethylene glycol, supplied and discharged under pressure from the outside. Inside the housing there is a centrifugal fan mounted on a driven shaft, which is mounted on two bearings. Torque is transmitted from the outside using a magnetic clutch, which ensures the tightness of the double-walled capsule. The upper part of the cooling unit has an outlet for feeding cooled air into the inner volume of the double-walled capsule. The inert chamber with five cooling units for pyrochemical processing operates as follows. The product being processed is placed in a double-walled capsule, where exothermic reactions occur, accompanied by active heat release, which heats up the argon contained in the inner cavity of the chamber. When the argon reaches a certain temperature, ethylene glycol is fed into the heat exchanger. Electric motors located outside the chamber are switched on and transmit torque through magnetic couplings, on the driven shafts of which centrifugal fans are installed. The centrifugal fans, rotating, create a pressure difference between the inlet and outlet openings of the cooling unit housings. The heated argon begins to be pumped through the heat exchangers, while cooling. Then the cooled argon is fed through the outlet openings of the cooling units into the inner volume of the chamber. Thus, a certain temperature of argon is maintained in the internal volume of the chamber [Development and validation of a thermophysical numerical model of an inert chamber for pyrochemical processing of spent nuclear fuel / A.A. Goryunov, E.A. Tikhonov, A.A. Vlasov, A.A. Bushuev. - Text: direct // Applied Mathematics and Control Sciences / Applied Mathematics and Control Sciences. - 2024. - No. 1. - P. 73-93. - DOI 10.15593/2499-9873/2024.1.05].

The disadvantage of this inert chamber with five cooling blocks is the presence of moving parts, such as an impeller and bearings. Since the radiation background is significant, the degradation of bearing materials limits their service life. Since a person cannot be in the chamber after starting it, disassembling the cooling blocks and replacing the bearings is carried out remotely using a manipulator. This process is labor-intensive and requires highly qualified manipulator operators and requires the inert chamber to be taken out of service.

The technical result of the proposed device is to increase reliability by eliminating moving parts in the internal volume of the chamber.

The technical result is achieved in that the inert chamber with a passive cooling system contains a double-walled capsule, a lock door, a heat exchanger, wherein the heat exchanger is placed on the inner surface of the side walls of the double-walled capsule, and the heat exchanger is separated from the inner space of the double-walled capsule by a partition installed in such a way that gaps are formed between the edges of the partition and the inner surfaces of the upper and lower walls of the double-walled capsule.

Fig. 1 shows a general view of the device (the outer shell of the double-walled capsule is not shown).

Fig. 2 shows a top view (the outer shell of the double-walled capsule is not shown).

Fig. 3 shows section A-A (the outer shell of the double-walled capsule is not shown).

Fig. 4 shows a local view B of section A-A (the outer shell of the double-walled capsule is not shown).

Fig. 5 shows the vector field of distribution of air mass flow velocities during operation.

Fig. 6 shows the temperature distribution field during operation.

The device includes a double-walled capsule 1 with an inert medium to prevent chemical reactions and a vacuum pressure to ensure safety in case of leakage. A heat exchanger 2 is installed on the inner surface of the side walls of the double-walled capsule 1 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6), which can be made as a single block having a supply and outlet of a refrigerant. Also, the heat exchanger 2 can be implemented in the form of several separate sections on each wall having their own supplies and outlets for a refrigerant, which can be, for example, ethylene glycol. The sections of the heat exchanger 2 can be implemented as a plate heat exchanger consisting of at least one curved tube to which vertical plates are attached. It is also possible that the plates can be removable. Moreover, the type of heat exchanger used does not affect the technical result. Heat exchangers 2 are separated from the internal volume of double-walled capsule 1 by vertical partitions 3 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6), installed in such a way that gaps 4, 5 are formed between the edges of partitions 3 and the internal surfaces of the upper and lower walls of double-walled capsule 1 (see Fig. 3, Fig. 4, Fig. 5, Fig. 6).

The device operates as follows. The product being processed is placed in a double-wall capsule 1. During the processing of the product, exothermic reactions occur, accompanied by active heat generation, which heats the inert medium. When a certain temperature is reached, cooled coolant is supplied to the input of heat exchanger 2. The surface of heat exchanger 2 cools, thereby cooling the inert medium in the space between the inner side wall of the double-wall capsule 1 and partition 3, where heat exchanger 2 is directly located. The cooled inert medium descends and exits into the internal volume through gap 5. In this case, the heated medium is sucked through gap 4 into the space between the inner wall and partition 3, where heat exchanger 2 is located, also cooling. This process is shown in Figure 5, where the vectors show the speed and direction of air mass flows. The heat transferred by the inert medium to heat exchanger 2 is removed from the system by the coolant through the outlet. In this way, the thermal balance is maintained during product processing, Fig. 6.

The device allows for increased reliability due to the removal of moving parts and the enlargement of the heat exchanger.

Claims (1)

An inert chamber with a passive cooling system, containing a double-walled capsule, a lock door, a heat exchanger, characterized in that the heat exchanger is placed on the inner surface of the side walls of the double-walled capsule, and the heat exchanger is separated from the inner space of the double-walled capsule by a partition installed in such a way that gaps are formed between the edges of the partition and the inner surfaces of the upper and lower walls of the double-walled capsule.