SU1753214A1 - Cooling system of installations with autonomous type of operation - Google Patents

Abstract

Using; in the systems providing temperature conditions in autonomous structures. The system contains a cold battery, a chiller, a heat exchanger associated with it, located in the battery tank, a thermosyphon, the condensation zone of which has contact with the side wall of the battery tank, and the evaporation zone has contact with the pipeline section of the circulation circuit to cool the coolant on it. The system is provided with a coolant circulation line through a battery containing inlet and outlet manifolds mounted on the upper and lower walls of the accumulator tank and communicated with its cavity and connected to the coolant circuit. The system is also equipped with a pipeline connected to the battery capacity in the area adjacent to the condensation zone of the thermosyphon, and also connected to the coolant circuit. 1 il. (Ls

Description

The invention relates to cold supply systems and can be used in temperature control systems in autonomous structures.

In order to ensure the temperature regime of autonomous functioning isolated objects, they are supplied with cooling systems. The main component of the cold supply system is the cold battery. At present, the most common ice cold batteries are.

A known system containing an air cooler, which absorbs the heat surplus released in the structure, a pump that pumps the thawed water through the air cooler and the capacity of the cold accumulator, a heat exchanger that provides freezing and maintenance of ice, the heat exchanger is connected to an external refrigerating machine.

The system has two modes of operation; duty and autonomous work. On duty, it freezes and maintains a supply of ice in the cold accumulator using a chiller. In the autonomous mode of operation, the refrigerating machine is turned off, the heat surpluses released in the structure in the air cooler and further into the ice of the cold accumulator are removed, while the ice supply is consumed.

A disadvantage of ice cold accumulators is the difficulty of ensuring a guaranteed flow between the vessel wall and the ice mass. To this end, in systems of this type, heat is supplied from the outside. This is, firstly, increasing VJ

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The thermal load on the chiller provides freezing and maintenance of ice supply, and, secondly, it reduces the ice supply in the cold accumulator (in known cold accumulators, the ice volume is about 3/4 of the water poured into it).

Closest to the invention is a cooling system consisting of an air cooler, a pump, an evaporative portion of a thermosyphon, an adiabatic portion, a condensation portion of a thermosyphon, a cold accumulator capacity, an additional heat exchanger, a surge tank, and a cooling machine,

In the autonomous mode of the system, the heated water from the air cooler enters the evaporative section of the thermosyphon, where it is cooled due to boiling of the working body of the thermosyphon, and the air cooler enters again. The vapor of the working medium of the thermosyphon along the adiabatic section enters the condensation section, where it falls on the outer surface of the vessel wall, condenses and flows into the evaporation section. When this occurs, ice melts in the tank.

In the duty mode, the coolant cooled by the refrigerating machine enters the heat exchanger, the additional heat exchanger and again into the refrigeration machine. An additional heat exchanger serves to reduce the size of the thawed zone, and, consequently, increase the amount of ice in the cold accumulator in the duty mode. The operation of the thermosyphon is similar to its work in the autonomy mode. As a working fluid of a thermosyphon, for example, an azeotropic mixture of freons boiling at 0 ° C at a pressure close to atmospheric can be used. The expansion tank is used to compensate for the volume expansion of water during its freezing.

However, when a melt zone is formed with a depth of more than 0.01 m over the entire surface of the wall adjacent to the condensation section, the temperature resistance of the water layer increases due to the insignificance of the melt water convection. This leads to an increase in the condensation temperature of the working medium of the thermosyphon and, consequently, an increase in the temperature of the water circulating through the heat exchanger.

The aim of the invention is to increase the temperature stability in the building by reducing the temperature gradient of water in the thawed cold accumulator zone and ensuring a constant level of water temperature in the heat exchanger for the entire period of autonomous operation.

The goal is achieved by the inclusion of two additional contours in the system diagram.

water circulation. One of them, turbulizing, is intended to increase convective heat exchange in the thawed zone of the cold accumulator by supplying a portion of cold water from the evaporative section.

thermosyphon. The second circuit is the main one. It is designed to supply warm water from the air cooler; the evaporator section of the thermosyphon directly into the cold storage tank, where this stream is cooled by this ice, after which cold water is fed back to the air cooler.

The presence of two additional water circuits reduces thermal

resistance of the thawed water layer due to the circuit of turbulization, and with decreasing g iccbi of ice in the cold storage tank capacity allows for direct contact of the cooled water with the ice

(but without the need to maintain special channels for this purpose on duty).

The invention allows to increase the temperature stability of the cooled water,

as compared with the prototype, special control devices are not required as they circulate through the air cooler, since the change in the flow of water through the circuits occurs spontaneously due to the thawing of the channels of the circuits. In this case, on duty, the volume of the cold battery is completely filled with ice.

The drawing shows a system diagram. The system consists of an air cooler.

1, pump 2, evaporative section 3 of thermosyphon, adiabatic section 4, section 5 of condensation, cold storage tank capacity b, additional heat exchanger 7, main heat exchanger 8, expansion tank 9, chiller 10 and additional elements: lower collector 12, upper collector 11 connecting highways 13 (these elements make up the main circuit) and highways

14 turbulizing circuit. Section 5 of the condensation is made toroidal. The system works as follows. In the non-autonomous mode of operation, the heat excess from the structure is transferred to the evaporation section of the thermosyphon through the heat exchanger by the water circuit, transferred by the working medium of the thermosyphon to the condensation section and through the vessel wall 6, the ice pack and heat exchangers 7 and 8 are carried away by the antifreeze of the refrigerating machine.

When the chiller is constantly running, the water in the tank 6 crystallizes completely and locks the upper 11 and lower 12 collectors. The flow of water through highways 14 and 13 of the turbulizing and main circuits is excluded, since there are no channels in the ice massif,

In case of short-term shutdown of the Chiller, the zone may form in the tank 6 at the condensation site of the thermosyphon. If the size of this zone increases to such an extent that it thaws the entrance of the line 14 and part of the lower collector 12, that through the formed flow the thawed water begins to circulate in the turbulizing circuit.

In the autonomy mode at the initial moment of time, when the entire volume of the cold accumulator is filled with ice, the water circulating through the air cooler is cooled in the evaporative part of the thermosyphon (as in the prototype system). After the formation of a thawed zone in the ice massif near the wall of the tank 6, the inlet and outlet of the main line 14 of the circulation loop are released.

Part of the flow of cold water after the pump 2 enters the gap between the vessel wall and ice, which increases the heat transfer coefficient from the condensation section to the ice mass and leads to a decrease in the condensation temperature of the working substance of the thermosyphon compared to the prototype, the hydraulic resistance of the line 14 must be greater than the resistance the water circuit formed by the air cooler 1 and the water mains passing through the evaporation section 3 of the thermosyphon. This is achieved by installing throttle washers in line 14. In this case, the main flow of water circulates through the evaporation section of the thermosyphon.

All heat flux absorbed by the water in the air cooler 1 is withdrawn into the ice of the cold accumulator through the thermosyphon and spent on its melting. As the volume of ice in the cold storage tank decreases, in the upper part of it the channels of the upper one and in the lower part of the lower collectors of the main water circuit open. This provides an increase in the flow of water through this circuit, since its hydroresistance decreases due to an increase in the number of parallel channels of the collectors. The flow of water circulating through the thermosyphon respectively decreases and the heat load on the condensation section of the thermosyphon also decreases, which helps to reduce the temperature difference between the vessel wall and the ice on it.

Adjustment of the hydraulic system of the proposed scheme is carried out during its assembly, due to the installation of hydraulic resistances in line 14 and control spills. It is important that the water flow through this line is less than that through the water line circulating through the evaporation section of the thermosyphon and through the main water circuit. And the ratio of expenses through these two last contours can be approximately the same.

The technical advantage of the invention is the following: the temperature in the structure is maintained regardless of the amount of ice in the cold accumulator unit, the period of autonomy of the structure is increased by the cold due to the full use of the accumulated ice supply.

Claims (1)

Claims The cooling system of structures with an autonomous mode of operation, comprising a cold battery, a refrigerating machine, a heat exchanger associated with it, located in the battery tank, an air cooler and a pump included in the refrigerant circuit, and a thermosyphon body in which the condensation zone is installed with ensuring thermal contact with the side wall of the battery tank, and in the evaporation zone, with the pipeline section of the circulation loop for cooling the coolant passing through it, characterized by that, in order to increase the temperature stability in the building, the system is equipped with a coolant circulation line through the battery and a pipeline connected to the coolant circuit between the pump and the air cooler and to the battery capacity in the area adjacent to the condensation zone of the thermosyphon, while coolant circulation through the battery contains containers installed on the upper and lower walls and communicating with its cavity evenly over the surface of the walls of the inlet and outlet collectors and pipelines for connecting the collectors to the coolant circuit, while the inlet manifold pipe is connected to the circulation circuit after the air cooler and the outlet manifold pipe is in front of the pump. Compiled by I.Shebalina Editor O.Yurkovetska Tehred M.MorgentalKorrektor M.Petrova Order 2756 Circulation (VNIIPI State Committee on Inventions and Discoveries at the State Committee on Science and Technology 113035, Moscow Zh-35, Raushsk nab., 4/5 ) i o, j Production and Publishing Combine Patent, g, Uzhgorod, Gagarin st., 101 Subscription