UA65039A - System for passive removal of heat from the production rooms of a nuclear power plant - Google Patents

Abstract

The present invention relates to a system for passive removal of heat from the production rooms of a nuclear power plant containing a nuclear reactor with an active zone and a protecting shell. The proposed system contains a tubular heat exchanger with a number of tubular sections. The evaporating sections are installed inside of the reactor protecting shell, and the condensing sections pass through the sealing elements of the protecting shell and the sealed production rooms.

Description

The invention relates to the field of energy and can be used in the development of passive elements of means of limiting the scale of accidents, primarily accidents with loss of coolant.

The well-known system of cooling the sealed premises of the nuclear power plant (see the book by O.B. Samoilov, G.B. Usinin, A.M.

Bakhmetyev. Safety of nuclear de-energizing installations.-M.: Znergoatomizdat, 1989, p. 85, fig. 5.18) includes a nuclear reactor with an active zone, a sprinkler device, a cooling water reserve tank, a pit, a heat exchanger of an emergency cooling system of an active zone. The main disadvantage of this system is that it refers to active means of cooling. This system cannot work in conditions of a complete blackout of the station, as it requires power and the presence of control signals for its operation.

The system of heat removal from the premises of the NPP was chosen as the closest in terms of technical essence (see the book by I.N.

Nygmatulin, B.I. Nygmatulin. Nuclear power plants.-M.: Znergoatomizdat, 1986, p. 159, fig. 5.1), which includes a nuclear reactor with an active zone, a casing of a protective shell or sealed rooms, a tubular heat exchanger. This more advanced system also requires for its operation the presence of energy sources for pumping cold water supplied to the tubular heat exchanger from the outside, and control, that is, it is active.

The invention is based on the task of creating a passive system of heat removal from the premises of the NPP, in which the new design of the elements for collecting, transferring and removing heat from the premises of the NPP would ensure passivity, efficiency and reliability of operation.

The task is solved by the fact that in the system of heat removal from the premises of the NPP, which contains a nuclear reactor with an active zone, the casing of the protective shell or hermetic premises, the tubular heat exchanger according to the invention is made in the form of a block of heat pipes, the evaporation sections of which are located inside the casing of the protective shell or hermetic rooms, and the condensation areas are brought out through the seals, made in the housing of the protective shell or hermetic rooms.

Designing a tubular heat exchanger in the form of a block of heat pipes, the evaporating sections of which are placed inside the casing of the protective shell or hermetic premises, and the condensing sections are led outside through the seals made in the casing of the protective shell or hermetic premises, allows to ensure the passivity, efficiency and reliability of the system operation due to independence operation of the heat pipe unit from the presence of power supply and control signals. The block of heat pipes allows you to efficiently collect heat inside the protective shell or hermetic premises, take it outside the protective shell or hermetic premises and disperse it in the environment. At the same time, the ingress of radioactive particles into the environment is practically excluded due to the fact that for their leakage it is necessary to break the integrity of the shell of at least one of the heat pipes twice, namely - inside the protective shell body or sealed rooms in its evaporation area and in the environment in the condensation area, and these violations of the integrity of the case must be in the same heat pipe.

The technical essence and principle of operation of the proposed passive heat removal system from the premises of the NPP is explained by the drawing (Fig. 1).

The drawing (Fig. 1) shows a cross-section of the passive heat removal system from the premises of the NPP. The passive heat removal system from the premises of the NPP includes a nuclear reactor 1 with an active zone 2, a casing of a protective shell or sealed premises 3, a heat exchanger 4, a block of heat pipes 5. The evaporation sections of heat pipes 6 are placed inside the casing of a protective shell or sealed premises 3, and their condensation areas 7 are released into the environment. Condensing sections 7 of heat pipes 5 are brought out through the seal 8, made in the case of a protective shell or sealed rooms 3.

The passive heat removal system from the premises of the NPP works as follows. In the event of an emergency situation (first of all, an accident with a loss of coolant), the hot coolant is ejected from the active zone 2 of the nuclear reactor 1 into the NPP premises into the containment shell or sealed rooms 3.

The hot coolant fills the heat exchanger 4 and enters the evaporation sections 6 of the package of heat pipes 5. The coolant of the heat pipes in the evaporation zones 6 evaporates or boils and transfers heat in the form of latent heat of vaporization to the condensation sections 7 outside the protective shell housing or sealed rooms 3. Here, the coolant of the heat pipes pipes condenses due to the cooling of the outer surface of the heat pipes in the environment and returns to the evaporating sections b of the heat pipe package 5. The evaporation-condensation cycle is closed. Atmospheric air, soil or water of a pool or reservoir can serve as the final heat absorber. Heat pipes can be equipped with fins completely or one of their sections - evaporation or condensation.

A model of a fragment of the passive heat removal system from the premises of the NPP was manufactured and tested, which included a hermetic chamber, into which the evaporation zones of two heat pipes located above each other were introduced through sealing. The condensing areas of the heat pipes were placed in the surrounding air. On the other side, a fitting for supplying hot water was soldered into the wall of the chamber.

As a result of the conducted tests, it was established that: - the removal of heat to the condensing areas of the heat pipes began after the supply of hot water inside the hermetic chamber; - by changing the characteristics of the block of heat pipes and the type of the final heat absorber, it is possible to develop a passive system of heat removal from the premises of the NPP that is optimal for specific conditions.

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Claims (1)

A passive heat removal system from the premises of nuclear power plants, which includes a nuclear reactor with an active zone, a casing of a protective shell or sealed premises, a tubular heat exchanger, which is characterized by the fact that the tubular heat exchanger is made in the form of a block of heat pipes, the evaporation areas of which are placed inside the casing of a protective shell or sealed premises, and the condensation areas are led outside through seals, made in the case of a protective shell or sealed premises.