JPH0638246Y2 - Refrigerant natural circulation type cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> In the present invention, a condenser on the heat source side and an evaporator on the utilization side are connected in communication via a refrigerant pipe, and the condenser, the evaporator, and It is configured to circulate and flow the refrigerant in a hermetically sealed state over the refrigerant pipe, and, as the refrigerant, a refrigerant that undergoes a phase change from liquid to vapor with heat exchange in the evaporator is used, and the condenser is used. Between the evaporator,
The present invention relates to a refrigerant natural circulation type cooling system having a head difference sufficient to transfer a refrigerant that has changed into a liquid phase to the evaporator.

<Prior Art> In this type of refrigerant natural circulation type cooling system, a refrigerant pipe for supplying a refrigerant liquid to an evaporator is connected to the evaporator through a space to be cooled such as a room, and therefore, via the refrigerant pipe. The refrigerant liquid is heated by this, a part of the refrigerant liquid is vaporized thereby to generate bubbles, and there is an inconvenience that the flow of the refrigerant liquid is obstructed by the bubbles, and as a technique for solving such an inconvenience,
Conventionally, the one disclosed in Japanese Utility Model Publication No. 61-15424 is known.

In this conventional example, a radiator pipe as a condenser and a liquid pipe that connects a heat absorber as an evaporator to each other are provided in an outer pipe that is communicatively connected to a lower portion of the heat absorber and an upper portion of the radiator. The outer tube and the refrigerant liquid inside the tube prevent the tube from being heated, and the refrigerant liquid in the liquid tube is prevented from being vaporized by heating.

<Problems to be solved by the invention> However, when the operation is stopped such as at night, the outer pipe is heated by the outside air for a long time, and accordingly, the refrigerant pipes leading to the condenser and the evaporator are also It is warmed by the outside air, the temperature of the refrigerant liquid in the refrigerant pipe rises, and the temperature becomes the same as the room temperature at the start of operation on the next day. When low-temperature energy is supplied to the condenser in such a state, the condenser side of the refrigerant pipe is cooled and the internal pressure there is reduced, the refrigerant liquid is vaporized in the refrigerant pipe accordingly, and the refrigerant is vaporized by the vaporized refrigerant vapor. The flow of the liquid is obstructed, and even the phenomenon that the refrigerant liquid flows backward to the condenser side occurs, it takes time until the refrigerant liquid is supplied to the evaporator, the startup of the cooling operation is delayed, and the operation starts. After that, there is a drawback that warm air is supplied to the room for a predetermined period of time to make the room uncomfortable.

Especially, the arrangement position of the condenser and the position of the refrigerant pipe through which the refrigerant liquid flows down are different, so that the refrigerant pipe from the condenser once extends horizontally at the top of the rooftop and then flows down vertically. When piped, there was a drawback that the refrigerant vapor stagnates in the horizontal pipe portion and the refrigerant liquid cannot flow down.

The present invention has been made in view of such circumstances, and the refrigerant natural circulation type cooling system according to the invention of claim (1), vaporizes the refrigerant liquid in the refrigerant pipe at the start of operation. The present invention aims to prevent a poor flow-down of the refrigerant liquid due to the above, and to make it possible to perform a comfortable cooling operation with a quick start-up of the cooling operation.
A refrigerant natural circulation type cooling system according to the invention of claim 1 is intended to prevent backflow of a refrigerant liquid to a condenser due to a decrease in internal pressure due to cooling in the condenser at the start of operation.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the present invention provides a refrigerant natural circulation type cooling system described at the beginning as a device of claim (1), from a condenser. A gas-liquid separation section is provided between the liquid receiver that receives the flowing-down refrigerant liquid and the evaporator, and the gas-liquid separation section and the upper space of the condenser are connected to each other through a gas vent pipe. Configure.

Further, as the invention of claim (2), in the structure of the refrigerant natural circulation type cooling system according to the invention of claim (1), a refrigerant pipe for flowing the refrigerant liquid from the condenser to the gas-liquid separation part. In addition, a configuration in which a check valve for preventing the reverse flow of the refrigerant liquid is provided is added.

<Operation> According to the configuration of the refrigerant natural circulation type cooling system according to the invention of claim (1), when the operation is stopped at night or the like, a part of the refrigerant liquid is evaporated by heating the outside air, Alternatively, even if a refrigerant vapor is generated in the refrigerant pipe that supplies the refrigerant liquid from the condenser to the evaporator due to vaporization of the refrigerant liquid due to a decrease in internal pressure due to cooling in the condenser accompanying the start of operation, those refrigerants The vapor can be separated from the refrigerant liquid by the gas-liquid separator and returned to the condenser via the gas vent pipe.

Further, according to the configuration of the refrigerant natural circulation type cooling system according to the invention of claim (2), the refrigerant liquid is sucked up to the condenser side due to the decrease in the internal pressure caused by the cooling in the condenser accompanying the start of operation. Can be prevented with a check valve.

<Embodiment> Next, an embodiment of the present invention will be described in detail with reference to the drawings.

<First Embodiment> FIG. 1 is an overall system configuration diagram showing a first embodiment of a refrigerant natural circulation type cooling system, and 1 is a condenser on the heat source side installed on the roof of a building or the like. , This condenser 1
It is designed to supply cold water or ice slurry from a heat source.

An individual air conditioner 4 including a blower fan 2 and an evaporator 3 is provided in each room on each floor of the building.

The condenser 1 and the evaporator 3 are connected to each other through a refrigerant pipe 7 in which a liquid receiver 5 and a gas-liquid separator 6 serving as a gas-liquid separator are interposed, and the condenser 1 and the evaporator The refrigerant that changes phase from liquid to vapor with heat exchange in the evaporator 3 and that changes from vapor to liquid due to condensation in the condenser 1 is enclosed in a hermetically sealed state over the condenser 3 and the refrigerant pipe 7. There is.

The liquid receiver 5 is installed at a position higher than each of the evaporators 3 ..., and the refrigerant that has been phase-changed from vapor to liquid by the condensation in the condenser 1 is supplied to the evaporator 3 while flowing down. Is provided with a head difference sufficient to return the refrigerant that has undergone a phase change from liquid to vapor due to heat exchange of and is returned to the condenser 1, and during the cooling operation, due to the phase change between vapor and liquid,
The refrigerant is configured to naturally circulate between the condenser 1 and the evaporator 3.

Freon gas R-22 is used as the refrigerant. This CFC gas R-22 contains hydrogen and chlorine and is decomposed in the troposphere, so that it has an advantage of not destroying the ozone layer.

At the inlet of the refrigerant pipe portion 7a for supplying the refrigerant liquid to each of the evaporators 3 of the refrigerant pipe 7, a flow rate control valve 8 for adjusting the refrigerant liquid inflow amount and an electromagnetic opening / closing valve 9 for preventing the refrigerant liquid inflow are provided. It is provided.

Evaporator 3 of the refrigerant pipe 7 ... A temperature sensitive tube 10 for sensing the temperature of the refrigerant vapor is provided at the outlet of the refrigerant piping portion 7b for discharging the refrigerant vapor from each of the evaporators. Of the flow control valve 8 is automatically adjusted so that the pressure difference is maintained constant. The flow rate control valve 8 has a structure similar to that of an automatic expansion valve used in a refrigeration system, and the pressure equalizing side thereof may be either an internal pressure equalizing type or an external pressure equalizing type. Further, as a configuration for controlling the supply amount of such a refrigerant liquid, even if it is performed by a thermistor that senses the saturation equivalent temperature of the refrigerant and an electrically operated flow control valve that adjusts the opening degree according to the sensed temperature. good.

The electromagnetic on-off valve 9 is closed when the cooling operation is stopped and is opened in association with the driving of the blower fan 2 when the cooling operation is started. In addition, in the cooling operation state, the electromagnetic on-off valve 9 is automatically controlled to be opened and closed by comparing a room temperature sensor that measures the temperature of the return air of the evaporator 3 with a set temperature, thereby setting the indoor temperature. Configured to stay within range.

Although not shown, it is arranged on each floor,
The portions of the horizontal refrigerant pipe 7 for supplying the refrigerant liquid to each of the evaporators 3 ... are provided so as to be inclined so that they become lower toward the side of the evaporators 3 ... so that the refrigerant liquid can be easily supplied to each of the evaporators 3. It is configured.

Further, the horizontal refrigerant pipe 7 portion for returning the refrigerant vapor generated in each of the evaporators 3 ... Is provided so as to be lower as it gets farther from the evaporator 3 side, and the refrigerant liquid in the refrigerant pipe 7 is Even if it is mixed, the refrigerant liquid is used for the evaporator 3 ...
It is configured so that it can easily flow down to the side away from each other.

The gas-liquid separator 6 is provided at a position deviated from the vertically lower position of the liquid receiver 5, and the gas-liquid separator 6 and the liquid receiver 5 are provided with a pipe portion 7c oriented in the horizontal direction. The refrigerant pipes 7 are connected for communication. Further, the pipe portion 7c facing the horizontal direction is provided with an upward slope toward the gas-liquid separator 6 side so that the refrigerant vapor generated in the pipe portion 7c easily flows to the gas-liquid separator 6 side. ing.

The upper space of the gas-liquid separator 6 and the upper space of the condenser 1 are connected to each other via a gas vent pipe 11, and are used for heating the outside air in an operation stopped state such as at night or for the condenser 1 accompanying the start of operation. If the refrigerant liquid is vaporized and the refrigerant vapor is generated in the pipe portion 7c, the gas-liquid separator 6 and the refrigerant pipe 7 below it due to the decrease in the internal pressure due to the cooling, the refrigerant vapor is generated. Is configured to return to.

Further, the upper space of the liquid receiver 5 and the upper space of the condenser 1 are communicatively connected via a pipe 12 so that the refrigerant liquid condensed and vaporized in the condenser 1 can smoothly flow down to the liquid receiver 5. ing.

Condenser 1 and liquid receiver 5, and liquid receiver 5 and gas-liquid separator 6
Check valves 13 and 14 are provided in each of the pipes that communicate with each other, and the internal pressure in the refrigerant pipe 7 is reduced due to the cooling in the condenser 1 accompanying the start of operation, and the refrigerant liquid flows to the condenser 1 side. Even if the liquid is sucked up, the refrigerant liquid can be prevented from flowing backward from the gas-liquid separator 6 side to the liquid receiver 5 side and from the liquid receiver 5 side to the condenser 1 side. Has been done.

<Second Embodiment> FIG. 2 is an overall system configuration diagram of a second embodiment of the refrigerant natural circulation type cooling system, and shows the refrigerant liquid side of the refrigerant pipe 7 connected to the condenser 1 and the evaporator 3 ... Both vertical pipes on the refrigerant vapor side are housed in the same vertical shaft 15, and the gas-liquid separator 6 as a gas-liquid separation unit is connected to the uppermost part of the vertical pipes on the refrigerant liquid side and separated from the vertical shaft 15. The liquid receiver 5 and the gas-liquid separator 6 vertically below the condenser 1 installed at a different position are connected by a refrigerant pipe 7 having a long pipe portion 7c oriented in the horizontal direction. This piping part 7c
Also, similarly to the above-described first embodiment, while being provided with an upward slope toward the gas-liquid separator 6 side, the upper space of the gas-liquid separator 6 and the upper space of the condenser 1 are connected via the degassing pipe 11. Connected for communication.

The operation and other configurations are the same as those in the first embodiment, and the same reference numerals are given and description thereof will be omitted.

The present invention can also be applied to the case where one evaporator 3 on the use side is provided and the cool air obtained by the evaporator 3 is distributed and supplied to each room or the like through the duct.

In the above embodiment, the gas-liquid separator 6 configured exclusively for gas-liquid separation is provided. However, in the present invention, for example, the end portion of the pipe portion 7c facing horizontally and the upper space of the condenser 1 are provided. May be configured to be connected and communicated via the gas vent pipe 11, and the structure for direct communication and connection to this pipe is referred to as a gas-liquid separation section.

<Effect of the Invention> According to the refrigerant natural circulation type cooling system according to the invention of claim (1), the refrigerant vapor in the refrigerant pipe for supplying the refrigerant liquid from the condenser to the evaporator is separated from the refrigerant liquid. Since it can be returned to the condenser, regardless of the generation of refrigerant vapor due to the decrease in internal pressure caused by the cooling of the refrigerant liquid in the condenser due to the heating at the time of operation stop and the start of operation, the refrigerant liquid causes the refrigerant liquid to flow down. It is possible to avoid the hindrance, to supply the refrigerant liquid smoothly and satisfactorily to the evaporator with the start of the operation, to speed up the start of the cooling operation, and to perform the cooling operation comfortably.

Further, according to the refrigerant natural circulation type cooling system according to the invention of claim (2), it is possible to prevent the refrigerant liquid from flowing backward from the gas-liquid separation portion side to the condenser side, and therefore, the cooling liquid is liquefied in the condenser. It is possible to prevent the flow of the refrigerant liquid from being obstructed, and to supply the refrigerant liquid to the evaporator more smoothly and satisfactorily with the start of operation, to speed up the start of the cooling operation and to perform the cooling operation comfortably. Is now possible.

[Brief description of drawings]

The drawings show an embodiment of a refrigerant natural circulation type cooling system according to the present invention. FIG. 1 is an overall system configuration diagram of the first embodiment, and FIG. 2 is an overall system configuration diagram of the second embodiment. . DESCRIPTION OF SYMBOLS 1 ... Condenser 3 ... Evaporator 6 ... Gas-liquid separator as a gas-liquid separation part 7 ... Refrigerant piping 11 ... Gas venting pipe

Front page continued (72) Inventor Kensuke Tokunaga 4-1-1 Honmachi, Chuo-ku, Osaka-shi, Osaka Takenaka Corporation, Osaka Main Store (72) Inventor Nozomi Kusumoto 4-1-1, Honmachi, Chuo-ku, Osaka-shi, Osaka No. 13 Takenaka Corporation Osaka Main Store (72) Inventor, Satoshi Sugiura 4-1-1 Honmachi, Chuo-ku, Osaka City, Osaka Prefecture Takenaka Corporation Osaka Main Store (72) Inventor Takeo Ueno Gold, Sakai City, Osaka Prefecture 1304 Okamachi Daikin Industry Co., Ltd. Sakai Seisakusho Kanaoka Factory (56) Reference JP 59-18362 (JP, A) JP 63-116051 (JP, A)

Claims (2)

[Scope of utility model registration request] 1. A condenser on the heat source side and an evaporator on the utilization side are connected in communication through a refrigerant pipe, and a refrigerant is circulated and circulated in a sealed state across the condenser, the evaporator and the refrigerant pipe. In addition, and, as the refrigerant, while using a refrigerant that undergoes a phase change from liquid to vapor with heat exchange in the evaporator, between the condenser and the evaporator, the phase change to a liquid In a refrigerant natural circulation type cooling system having a head difference sufficient to transfer a refrigerant to the evaporator, a gas-liquid separation unit is provided between a receiver that receives the refrigerant liquid that flows down from the condenser and the evaporator. And a gas-liquid separating section and an upper space of the condenser are connected to each other through a gas vent pipe. 2. A natural refrigerant circulation in which a check valve for preventing backflow of the refrigerant liquid is provided in the refrigerant pipe for flowing the refrigerant liquid from the condenser to the gas-liquid separating section according to claim 1. Air conditioning system.