JPH11230578A - Heating-cooling air-conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an energy loss due to the mixing of low-temperature and high-temperature media being fed to an outdoor unit that provides a double- type heating-cooling air-conditioning system and functions as both an evaporator and a condenser. SOLUTION: In a heating-cooling air-conditioning system, a first heat exchange unit 12 at an air-conditioning load side and a second heat exchange unit 10 at a heat source side are connected by a piping system using a piping system while the second heat exchange unit 10 is installed at a higher location than the first heat exchange unit 12, a refrigerant is naturally circulated on cooling, and at the same time a refrigerant liquid is pumped to the second heat exchange unit 10 at a high location by a liquid-feeding pump 16 or the like being provided in the piping system on heating. In the system, a circulation system 21 for feeding a low-temperature medium on cooling operation and a circulation system 22 for feeding a high-temperature medium on heating operation are independently provided for a heat exchanger being arranged in the second heat exchange unit 10. The outdoor unit may be arranged at a lower location than an indoor unit. In that case, the refrigerant is naturally circulated on heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling / heating air-conditioning system for naturally circulating a refrigerant, and more particularly to a two-tube cooling / heating air-conditioning system.

[0002]

2. Description of the Related Art In a cooling / heating / air-conditioning system, in order to circulate a refrigerant naturally during both cooling and heating, a heat exchange unit (indoor unit) on the air-conditioning load side arranged in a room to be air-conditioned is provided independently. It is necessary to employ a four-pipe circulating system provided with two circulating systems. This example is shown schematically in FIG. In FIG. 1, the moving path of the refrigerant gas is indicated by a broken-line arrow, and the moving path of the refrigerant liquid is indicated by a solid-line arrow.

At the time of cooling, a circulating system comprising an indoor unit 1 and a heat source side heat exchange unit (outdoor unit) 2 which is provided at a higher place and functions as a condenser, is connected by transport pipes 3 and 4. (Cooling cycle) is used. That is, the refrigerant gas vaporized in the heat exchanger in the indoor unit 1 rises in the transport pipe 4 to reach the outdoor unit 2, and
The refrigerant liquid condensed by the heat radiation in the outdoor unit 2 descends in the transport pipe 3 by the action of gravity, and the indoor unit 1
Leads to.

At the time of heating, a circulation system in which the indoor unit 1 and a heat source side heat exchange unit (outdoor unit) 5 which is provided at a lower place and functions as an evaporator is connected by transport pipes 6 and 7. (Heating cycle) is used. That is, the refrigerant gas liquefied by heat radiation in the heat exchanger in the indoor unit 1 descends inside the transport pipe 6 by the action of gravity to reach the outdoor unit 5, and the refrigerant gas vaporized by heat absorption in the outdoor unit 5 transports the transport pipe. 7 to reach the indoor unit 1.

[0005] The four-pipe natural circulation system shown in FIG. 1 has the advantage that no power such as a pump for circulating the refrigerant is required, while the indoor unit is used for performing both cooling and heating. However, there is a disadvantage that the outdoor unit must be arranged on both sides of the high place and the low place. In other words, the natural circulation system is based on the principle that the liquefied refrigerant is moved downward by the action of gravity and the vaporized refrigerant gas is moved upward from below. It is necessary to use an arranged heat exchanger (condenser), and to use a heat exchanger (evaporator) arranged lower than the indoor unit for heating.

On the other hand, a two-pipe air-conditioning system that performs cooling and heating using only an outdoor unit disposed above or below an indoor unit is conceivable. In such an air-conditioning system, One outdoor unit
(Or each of the plurality of outdoor units) is also used as an evaporator and a condenser. That is, when the outdoor unit functions as an evaporator, a high-temperature medium is sent to the outdoor unit, and when the outdoor unit functions as a condenser, a low-temperature medium is sent. Like this one
When two outdoor units have both functions as an evaporator and a condenser, energy loss occurs when a high-temperature medium and a low-temperature medium are mixed.

[0007]

Therefore, a technical problem to be solved by the present invention is to use an outdoor unit which is arranged only on the high side or the low side with respect to the indoor unit.
In addition to providing a tubular air-conditioning / air-conditioning system, in this case, it is possible to prevent a low-temperature medium and a high-temperature medium sent to an outdoor unit, which functions as an evaporator and a condenser, from being mixed to cause energy loss. That is.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to effectively solve the above-mentioned problems, and provides a cooling and heating air conditioning system having the following configuration.

That is, the cooling and heating air conditioning system of the present invention comprises a first heat exchange unit (hereinafter, referred to as an indoor unit) on the air conditioning load side and a second heat exchange unit (hereinafter, the outdoor unit) on the heat source side arranged in the room to be air conditioned. The unit is connected with a piping system in a state where the outdoor unit is installed at a higher position than the indoor unit.When cooling, the refrigerant naturally circulates, and at the time of heating, a liquid feed pump or a liquid supply pump provided in the piping system. A cooling and heating air-conditioning system that pumps a refrigerant liquid from a low place to an outdoor unit at a high place with an ejector, and a circulation system that sends a low-temperature medium during a cooling operation to a heat exchanger disposed in the outdoor unit; It is characterized in that two circulating systems for sending a high-temperature medium during operation are provided independently.

In the air conditioning / heating air conditioning system having the above-described structure, one outdoor unit is used as both an evaporator and a condenser because the refrigerant liquid is pumped from a low place to a high place using a liquid feed pump or an ejector during heating. Accordingly, cooling and heating can be performed using a two-pipe piping system using only an outdoor unit disposed at a higher place than the indoor unit. Further, in this case, one outdoor unit (or each of the plurality of outdoor units) also functions as a condenser and an evaporator. Are sent through independent circulation systems, so that they do not mix and thus do not cause energy loss.

[0011] In the cooling and heating air conditioning system of the present invention,
Instead of the above configuration, the outdoor unit may be arranged lower than the indoor unit. In this case, the refrigerant liquid is pumped using a liquid feed pump or an ejector during cooling,
The refrigerant naturally circulates during heating.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 2 is a schematic explanatory diagram showing an example of the cooling and heating air conditioning system of the present invention.

The outdoor unit 10 is disposed at a higher position than each of the indoor units 12, and during cooling, the refrigerant liquid liquefied by heat radiation in the outdoor unit 10 moves down the transport pipe 19 by the action of gravity. During cooling, the valve 14 is open and the valve 15 is closed, so that the refrigerant liquid descending the transport pipe 19 avoids the refrigerant liquid without flowing to the liquid feed pump 16 and moves toward the indoor units. Moving. This refrigerant liquid is vaporized by heat exchange in the indoor unit 12 and rises in the transport pipe 17 to move out of the outdoor unit 10.
Returned to.

In the case of performing cooling and heating in a two-pipe system using only an outdoor unit arranged at a higher position than an indoor unit,
The refrigerant can be naturally circulated during cooling, but cannot be naturally circulated during heating. Therefore, in the air conditioning system of FIG.
The refrigerant liquid is forcibly sent to the outdoor unit 10 at a high place by using 16. That is, the refrigerant liquid liquefied by the heat radiation in each indoor unit 12 moves to the pump 16 provided at a lower position, and is pumped by the pump to the outdoor unit 10 at a higher position through the transport pipe 19. This refrigerant liquid is vaporized by heat absorption in the outdoor unit 10 and reaches each indoor unit 12 through the transport pipe 17.

As can be seen from the above description, in the air conditioning system of FIG. 2, the outdoor unit 10 functions as a condenser during cooling and as an evaporator during heating. That is,
During cooling, a low-temperature medium such as brine or cold water is supplied to the outdoor unit 10 to remove heat from the refrigerant gas and liquefy it.
Passed through. On the other hand, at the time of heating, a high-temperature medium such as steam or hot water is passed through the outdoor unit 10 in order to apply heat to the refrigerant liquid to vaporize it.

This means that one heat exchanger is disposed in the outdoor unit 10, and a circulation system for passing the low-temperature medium and a circulation system for passing the high-temperature medium to the heat exchanger are arranged using valves. This can be achieved by switching and connecting, but in that case, there is a possibility that energy loss may occur due to mixing of the high-temperature medium and the low-temperature medium.

Therefore, in the present invention, as shown in FIG. 2, a so-called double bundle type heat exchanger combining two heat exchangers 21 and 22 is used to completely separate the two circulation systems. ing. In the example of FIG. 2, a low-temperature medium such as brine or cold water flows through the heat exchanger 21 during the cooling operation, and a high-temperature medium such as steam or hot water flows through the heat exchanger 22 during the heating operation. That is, in the air conditioning system of the present invention, since the low-temperature medium and the high-temperature medium sent to the outdoor unit 10 pass through completely independent separate circulation systems, they are not mixed and energy loss can be prevented. . In the illustrated example, two independent heat exchangers 21 and 22 are arranged in the outdoor unit.
(That is, the heat exchanger 21 forms a part of a circulation system for sending a low-temperature medium, and the heat exchanger 22 forms a part of a circulation system for sending a high-temperature medium.) The same effect can be obtained by providing two tubes as described above and flowing a low-temperature medium through one tube and a high-temperature medium through the other tube.

In the air conditioning system shown in FIG. 2, the liquid feed pump 16 is used to pump the refrigerant liquid during heating, but in the present invention, an ejector is used instead of the liquid feed pump as a means for pumping the refrigerant liquid. It is also possible to use it. FIG. 3 shows such an example.

In the air conditioning system shown in FIG. 3, during cooling, the refrigerant liquid condensed in the outdoor unit 30 descends in the transport pipe 42 by the action of gravity, passes through the ejector 34, and passes from the transport pipe 41 to each indoor unit 32. To. The refrigerant liquid is vaporized in the heat exchanger in the indoor unit, rises in the transport pipe 40, and returns to the outdoor unit 30. During cooling, the valve 36 is opened and the valve 35 is closed.

At the time of heating, the refrigerant gas vaporized in the outdoor unit 30 descends in the transport pipe 40 and heads toward the indoor unit 32. At a branch point 50 on the way, a part of the refrigerant gas passes through the valve 35. Head to Ejector 34. Indoor unit 32
The refrigerant gas that has proceeded to is liquefied by heat radiation, descends in the transport pipe 41, and proceeds toward the valve. The valve 36 is initially closed, and the refrigerant liquid is stored upstream thereof.

Heating proceeds, and the upstream side of the outdoor unit 30
When the valve 35 is opened when the pressure in the (in the transfer pipe 42) is reduced, a jet flows from the right side to the left side in FIG. 3 in the ejector 34 due to the pressure difference between the upstream side and the downstream side of the ejector 34. At this time, when the valve 36 is opened, the refrigerant liquid stored on the upstream side is sucked up into the ejector 34 and pushed up through the transport pipe 42 to the outdoor unit 30 at a high place. In this way, the refrigerant liquid can be pumped to the outdoor unit at a high place without using a power unit such as a liquid sending pump.

When the refrigerant liquid is pumped using the ejector, it is necessary to control the opening degree of the valves 35 and 36 while monitoring the pressure balance between the upstream side and the downstream side of the ejector. A pressure detector 37 is disposed in a pipe connecting the ejector 34 and the valve 36 to monitor the pressure.

The structure of the outdoor unit 30 is the same as that of the outdoor unit 10 of FIG. 2, and the heat exchangers 52 and 53 are
These correspond to the heat exchangers 21 and 22 of the outdoor unit 10, respectively.

In the embodiment described above, the outdoor unit is provided at a higher position than the indoor unit.
In the present invention, it is possible to arrange the outdoor unit at a lower position than the indoor unit. In this case, the refrigerant is naturally circulated during heating, and the refrigerant is pumped to an indoor unit at a high place using an ejector during cooling.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically illustrating a four-tube air-conditioning air-conditioning system in which a refrigerant naturally circulates during both cooling and heating.

FIG. 2 is an explanatory diagram showing an example of a cooling and heating air conditioning system of the present invention.

FIG. 3 is an explanatory diagram showing another example of the cooling and heating air conditioning system of the present invention.

[Explanation of symbols]

 1 Indoor unit 2, 5 Outdoor unit 3, 4, 6, 7 Transport pipe 10, 30 Outdoor unit 12, 32 Indoor unit 13, 33 Expansion valve 14, 15, 35, 36 Valve 16 Liquid feed pump 17, 18, 19, 40, 41, 42 Transfer tube 34 Ejector 37 Pressure detector 50 Branch point 21, 22, 52, 53 Heat exchanger

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor ▲ Yoshi ▼ Yuji Takenaka 4-1-1-13 Honcho, Chuo-ku, Osaka City, Osaka Inside Takenaka Corporation Osaka Main Store (72) Inventor Motohiro Motohara Osaka, Osaka Shinko Kogyo Co., Ltd. 1-4-5 Minamimorimachi, Kita-ku, Yokohama-shi

Claims (2)

[Claims] 1. A first heat exchange unit (12, 32) on the air-conditioning load side and a second heat exchange unit (10, 30) on the heat source side, which are arranged in a room to be air-conditioned. It is connected by a piping system in a state where it is installed at a higher place than the first heat exchange unit. During cooling, the refrigerant circulates naturally, and at the time of heating, a liquid sending pump (16) or an ejector (34) provided in the piping system. ) To transfer the refrigerant liquid from a low place to a high place in the second heat exchange unit (1
A cooling / heating air-conditioning system that pumps a low-temperature medium to a heat exchanger disposed in the second heat exchange unit (10, 30) during a cooling operation (21, 5).
2) and a circulating system (22, 53) for feeding a high-temperature medium during a heating operation are provided independently of each other. 2. The first heat exchange unit on the air-conditioning load side and the second heat exchange unit on the heat source side, which are arranged in the room to be air-conditioned, such that the second heat exchange unit is located lower than the first heat exchange unit. It is connected by a piping system in the installed state, and naturally circulates the refrigerant at the time of heating, and the first heat exchange unit from a low place to a high place by using a liquid sending pump or an ejector provided in the piping system at the time of cooling. A cooling / heating air-conditioning system that pumps air to the heat exchanger disposed in the second heat exchange unit, a circulation system that sends a low-temperature medium during cooling operation and a circulation system that sends a high-temperature medium during heating operation. An air-conditioning / air-conditioning system, wherein two air conditioners are provided independently.