JPH07117256B2 - Building air conditioning system - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a building air-conditioning system, and more particularly to a system that performs both cooling and heating by using a gravity heat pipe as its heat transfer system.

[Prior art]

The applicant of the present invention has already applied for an invention relating to a building air-conditioning system that performs both cooling and heating by using a gravity type heat pipe for the heat transfer system as described above (Japanese Patent Application No. 61-2643).
No. 09), but in the building air-conditioning system of this application, the cooling circuit and the heating circuit are independently configured. That is, the gravity type heat pipe that constitutes the cooling circuit and the gravity type heat pipe that constitutes the heating circuit do not have a shared portion regarding the refrigerant circulation path, and therefore the cooling circuit has an amount corresponding to the cooling load. This refrigerant should be sealed in the heating circuit in an amount corresponding to the heating load.

[Problems to be Solved by the Invention]

Generally, the peak heating load is about 65% of the cooling peak load.
The heating value of a normal heating device is set to about 65% of the cooling capacity of the cooling device. Therefore, in the building air-conditioning system having the above-described configuration, if 100 refrigerants are filled in the cooling circuit, the heating circuit has about 6
The refrigerant of 5 will be enclosed, and the total amount of refrigerant will require about 165 refrigerants. However, even if the refrigerant is used to the maximum, it is only during operation at the peak load of cooling, and the amount is about 60% of the total amount of refrigerant (100/165). About 40% of the remaining refrigerant is not used for heat transfer in the heating circuit. Furthermore, in the case of heating operation, the total amount of refrigerant is approximately
Only 40% (65/165) of the refrigerant is used. As described above, although the total amount of the refrigerant actually enclosed is large, the amount of the refrigerant required for the operation is at most 60%, and the useless refrigerant must be used. In addition, especially in the heating operation, since the load during the startup operation is extremely large, it is desirable that the heat exchange efficiency can be improved even temporarily, but the heat exchanger in the air conditioning unit has a general configuration. In some cases, the only means possible is to increase the speed of the blower. The present invention has been devised in order to effectively solve these problems in view of the problems of the prior art as described above. Therefore, the purpose is to eliminate unnecessary refrigerant encapsulation in a building air conditioning system that uses a gravity heat pipe for its heat transfer system,
An object of the present invention is to provide a system capable of performing cooling / heating operation with a minimum required amount of refrigerant charged, and temporarily increasing heat exchange efficiency during startup operation of heating.

[Means for Solving the Problems]

The building air conditioning system according to the present invention is configured as follows in order to solve the problems of the prior art and achieve the object. That is, a first condenser installed as a cold heat source side device heat exchanger in a high place of a building, and a heat load side heat exchanger in an air conditioning unit installed in a building lower than the first condenser. And a first evaporator as a heat exchanger are connected to each other by a first refrigerant liquid pipe and a first refrigerant gas pipe in a reciprocating manner to form a cooling circuit, and installed as a heat source side heat exchanger in a low place of the building. The second evaporator and the second condenser as a heat load side heat exchanger in the air conditioning unit are reciprocally connected by a second refrigerant liquid pipe and a second refrigerant gas pipe to form a heating circuit. A first on-off valve is provided between the first and second refrigerant liquid pipes, and a second on-off valve is similarly provided between the first and second refrigerant gas pipes. Between the cooling circuit and the heating circuit so that the total amount of the refrigerant is approximately equivalent to the peak load of cooling. It is constructed by sealing. Here, the "approximately equivalent amount" means that, when the refrigerant moves from the heating circuit to the cooling circuit, the refrigerant remains as gas in the heating circuit depending on the volume and the pipe shape of the heating circuit. Even if there is any, it is described as "generally" to mean the amount of refrigerant that can be sufficiently recovered to cover the peak load of cooling in the cooling circuit. Further, in the first refrigerant gas pipe, the highest branch portion of the pipe line from the second opening / closing valve to the air conditioning unit and the pipe line to the first condenser, and the refrigerant gas of the first condenser. Between the inlet or in the first refrigerant liquid pipe,
An uppermost branch portion of a pipe line from the first condenser to the first opening / closing valve and a pipe line to the air conditioning unit;
A third on-off valve may be provided at least one of between the condenser and the refrigerant liquid outlet.

[Action]

According to the building air conditioning system of the present invention, switching between the cooling operation and the heating operation is performed by the switching opening / closing operation of the first and second opening / closing valves. Further, by combining with the switching opening / closing operation of the third opening / closing valve, switching between the steady operation and the rising operation of heating is also performed. First, when the cooling operation is switched to the heating operation, the second opening / closing valve is closed and the first opening / closing valve is opened, so that the refrigerant in the cooling circuit flows into the heating circuit via the first opening / closing valve. In this case, most of the refrigerant is moved by gravity. The inflow amount is at least an amount corresponding to the peak load of heating. When the movement of the refrigerant is completed, the first opening / closing valve is closed again, and the heating circuit and the cooling circuit are separated from each other. When the heating operation is switched to the cooling operation, the first opening / closing valve is closed and the second opening / closing valve is opened, and heat exchange is performed until all the refrigerant in the second evaporator is vaporized, thereby heating the heating circuit. Most of the refrigerant therein is recovered to the cooling circuit from the second gas pipe via the second opening / closing valve. When the refrigerant recovery is completed, the second opening / closing valve is closed again, and the cooling circuit and the heating circuit are separated and independent from each other. During the heating start-up operation, both the first and second opening / closing valves are opened and the third opening / closing valve is closed while the refrigerant is in the heating circuit. In addition to the normal heating circuit, the refrigerant is in order from the second evaporator to the second gas pipe, the second opening / closing valve, the first gas pipe, the first evaporator, the first liquid pipe, the first opening / closing valve, and the second liquid receiving. Second through the vessel
A natural refrigerant circulation path is formed by using a part of the cooling circuit which should be called a second heating circuit returning to the evaporator.

【Example】

A preferred embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a building air conditioning system of the present invention.
Although the configuration of the building is not shown in this figure, the upper side of the figure shows the high side of the building, and the installation position of each configuration is defined by the height relationship. That is, the first condenser 3 as the heat radiation side heat exchanger of the cooling circuit 1 is installed at the highest position, and the second evaporator 6 as the heat absorption side heat exchanger of the heating circuit 2 is installed at the lowest position. Has been done. Further, at the height position between the first condenser 3 and the second evaporator 6, the first evaporator 4 as the heat absorption side heat exchanger of the cooling circuit 1 and the heat radiation side heat exchanger of the heating circuit are provided. Second condenser 5
The air-conditioning units 7 that have built-in units are installed in groups on each floor. The cooling circuit 1 includes a first refrigerant liquid pipe (hereinafter simply referred to as a first liquid pipe) and a first refrigerant gas pipe (hereinafter simply referred to as a first gas) between the first condenser 3 and the first evaporator 4. It is connected in a reciprocating manner by a pipe). Further, in the heating circuit 2, a portion between the second evaporator 6 and the second condenser 5 is a second refrigerant liquid pipe (hereinafter, simply referred to as a second liquid pipe) and a second refrigerant gas pipe (hereinafter,
It is reciprocally connected by a second gas pipe). The first liquid pipe 8 and the second liquid pipe 10 are first vertical pipe portions of the first liquid pipe 8 and the second liquid pipe 10, respectively.
The first on-off valve 13 is connected via the second on-off valve 14, and the first gas pipe 9 and the second gas pipe 11 are also connected on the respective vertical pipe portions via the second on-off valve 14. The cooling circuit 1 and the heating circuit 2 are filled with a refrigerant in an amount that approximately corresponds to the cooling load in both circuits. Third and fourth opening / closing valves 15 and 16 are provided on the refrigerant gas inlet side and the refrigerant liquid outlet side of the first condenser 3, respectively. This third,
The fourth on-off valves 15 and 16 are the highest branch portion P _{1 of} the first gas pipe 9 between the second on-off valve 14 and the air conditioning unit 7, and the first condenser 3. Between the refrigerant gas inflow port 29 of the first condenser 3 or in the first liquid pipe 8, the highest level of the pipeline from the first condenser 3 to the first opening / closing valve 13 and the pipeline to the air conditioning unit 7. Branch portion P ₂ of the first condenser 3
Corresponding to the third opening / closing valve interposed between at least one of the refrigerant liquid outlet 30 and the refrigerant liquid outlet 30. A first liquid receiver 19 is provided immediately downstream of the fourth opening / closing valve 16 in the first liquid pipe 8. On the other hand, on the refrigerant liquid inlet side of the second evaporator 6,
A first flow control valve 21 is provided, and a fifth opening / closing valve 17 is provided on the refrigerant gas outlet side. Further, immediately upstream of the first flow rate control valve 21 provided in the second liquid pipe 10, a second liquid receiver 20 is provided at a position higher than the second evaporator 6, and A sixth opening / closing valve 18 is provided immediately upstream of the second liquid receiver 20. A liquid level detection switch 22 as a liquid level control means is attached to the second evaporator 6 in order to keep the refrigerant liquid level inside the second evaporator 6 properly. 1 Flow control valve 21
These are electrically connected so that they can be opened and closed. As shown in FIG. 2, each air conditioning unit 7 has, as shown in FIG. 2, a first evaporator 4 as a cooling heat exchanger, a second condenser 5 as a heating heat exchanger, and a blower 23. The thermistor 24 for detecting the temperature of the recirculation room air sucked into the blower 23 is built in. In addition, second and third flow rate control valves 25 and 26 are provided on the refrigerant liquid inlet side of the first evaporator 4 and the refrigerant gas inlet side of the second condenser 5, respectively, and particularly the first evaporator. A liquid level detecting sensor 27 as a liquid level detecting means is attached to 4. Further, a controller 28 to which each output detection signal from the thermistor 24 and the liquid level detection sensor 27 is input is also provided. The controller 28 performs arithmetic processing on the basis of these signals, calculates the respective opening degrees of the second and third flow rate control valves 25 and 26, and the rotation speed of the blower 23 to calculate the flow rate control valves.
An operation command signal for instructing each opening degree and rotation speed is output to 25 and 26 and the blower 23. The operation of the building air conditioning system configured as described above will be described below. First, in the cooling and heating circuits 1 and 2 of the present embodiment configured by the gravity type heat pipe, the refrigerant enclosed therein circulates naturally between the heat source side and the load side to carry heat. This natural circulation is performed as follows. That is, the refrigerant changes from refrigerant gas to refrigerant liquid with heat exchange in the condensers 3 and 5, and the refrigerant liquid flows down in the liquid pipes 8 and 10 by gravity and flows into the evaporators 4 and 6. In the evaporators 4 and 6, the refrigerant liquid changes into a refrigerant gas with heat exchange, and the refrigerant gas rises in the gas pipes 9 and 11 by the gas pressure and returns to the condensers 3 and 5 again. In the cooling and heating circuits 1 and 2 in which natural circulation is performed as described above, it is assumed that all the refrigerant is initially in the cooling circuit 1. When the cooling operation is performed in this state, the first and second
The on-off valves 13 and 14 are closed so that the cooling circuit 1 is separated from the heating circuit 2 independently. The amount of refrigerant required for the peak load of cooling is ensured in the cooling circuit 1, and the amount of refrigerant corresponding to the load at that time naturally circulates in the cooling circuit 1. Next, when all the refrigerant is in the cooling circuit 1 and is switched from the cooling operation to the heating operation,
The on-off valve 13 is opened so that the refrigerant liquid contained in each of the first evaporator 4, the first receiver 19 and the first liquid pipe 8 of the cooling circuit 1 becomes the first refrigerant liquid.
The second liquid receiver 20 installed at a lower position through the on-off valve 13
And flows into the second evaporator 6. The refrigerant liquid level in the second evaporator 6 is properly maintained by the liquid level detection switch 22 and the first flow rate control valve 21. At the time of this switching, the third and fourth on-off valves 15 and 16 provided at the inlet and outlet of the first condenser 3 are closed, but the inflow amount of the refrigerant is the amount of the refrigerant required at the peak load of heating, that is, the amount of the refrigerant. At least about 65% of the refrigerant amount corresponding to the peak load may be secured, and some may remain in the cooling circuit 1. Although the sixth opening / closing valve 18 at this time is open and does not hinder the flow of the refrigerant, the sixth opening / closing valve 18 is an opening / closing valve for maintenance, and is always open during system operation. When the inflow of the refrigerant is completed, the first on-off valve 13 is closed, and the normal heating operation can be performed. In heating operation, especially during the start-up operation,
The fourth on-off valves 15, 16 are both closed and the first and second on-off valves 13,
By opening 14 together, the refrigerant in the heating circuit 2 can be supplied as refrigerant gas to the two heat exchangers in the air conditioning unit 7, which are the first evaporator 4 and the second condenser 5. That is, the second condenser 5 and the second condenser 5 during the normal heating operation
In addition to the refrigerant natural circulation path of the liquid pipe 10, the second evaporator 6 and the second gas pipe 11, the second gas pipe 11,
The second on-off valve 14, the first gas pipe 9, the first evaporator 4, the first liquid pipe 8, the first on-off valve 13, the second liquid receiver 20, and the second evaporator 6 are returned again. The refrigerant natural circulation path which should be called the heating circuit of No. 2 is formed. As a result, the heat exchange efficiency of each air conditioning unit 7 is approximately doubled as compared with the normal heating operation, and the steady operation state can be quickly achieved in response to the high load during the startup operation. When returning to the steady operation, if only the second opening / closing valve 14 is first closed from the start-up operation state, the refrigerant in the first evaporator 4 and the first liquid pipe 8 flows down, and passes through the first opening / closing valve 13. The first on-off valve 13 may be further closed after the liquid is collected in the second liquid receiver 20 and roughly collected. When switching from the heating operation to the cooling operation, the third and fourth opening / closing valves 1 with the first opening / closing valve 13 closed.
By opening 5, 16 and the second on-off valve 14, the second evaporator 6
Refrigerant that has been evaporated and vaporized in the second gas pipe 11 to the second opening / closing valve 1
4, It is recovered by the first condenser 3 via the first gas pipe 9, condensed here, and the refrigerant liquid is supplied into the first liquid receiver 19 and the first liquid pipe 8. After the refrigerant in the heating circuit 2 is almost recovered, the second opening / closing valve 14 is closed to separate the heating circuit 2 and the cooling circuit 1,
Then, the normal cooling operation is performed.

【effect】

As is clear from the above description, according to the present invention, the following excellent effects are exhibited. That is, in a building air conditioning system that has a cooling circuit and a heating circuit by a gravity heat pipe in its heat transfer system, the amount of refrigerant enclosed in the heat transfer system can be minimized,
Further, during the rising operation of the heating operation, the heat exchange efficiency can be increased to shorten the time until the steady operation state is reached.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment relating to a building air conditioning system of the present invention, and FIG. 2 is a schematic diagram showing a schematic configuration of an air conditioning unit in the present embodiment. 1 ... Refrigerant circuit, 2 ... Heating circuit, 3 ... First condenser,
4 ... 1st evaporator, 5 ... 2nd condenser, 6 ... 2nd evaporator, 7 ... Air conditioning unit, 8 ... 1st liquid pipe, 9 ... 1st
Gas pipe, 10 ... second liquid pipe, 11 ... second gas pipe, 13 ... first on-off valve, 14 ... second on-off valve, 15 ... third on-off valve, 16 ...
… 4th on-off valve, 29 …… Refrigerant gas inlet of the 1st condenser, 30
...... Prefrigerant liquid outlet of the first condenser, P ₁ ...... The highest branch part between the pipeline from the second opening / closing valve to the air conditioning unit and the pipeline to the first condenser, P ₂ ...... First The highest branch part of the pipeline from the condenser to the first on-off valve and the pipeline to the air conditioning unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadahiro Fukunaga 4-27, Honmachi, Higashi-ku, Osaka, Osaka Prefecture Takenaka Corporation (72) Inventor, Yasutoshi Yoshida, Okawa-cho, Higashi-ku, Osaka, Osaka Building Inside Shinko Industrial Co., Ltd. (72) Inventor Setsuo Kaneda 1 Okawa-cho, Higashi-ku, Osaka-shi, Osaka Nichichiyodo Yabashi Building Inside Shinko Industry Co., Ltd.

Claims (2)

[Claims] 1. A first condenser (3) installed as a heat exchanger on the side of a cold heat source device in a high place of a building, and the first condenser (3).
A first refrigerant liquid pipe (8) and a first refrigerant between the first evaporator (4) as a heat load side heat exchanger in the air conditioning unit (7) installed in a building lower than A second evaporator (6) installed as a heat exchanger on the side of the heat source device in the lower part of the building to form a cooling circuit (1) reciprocally connected by a gas pipe (9), and the air conditioning unit ( A second refrigerant liquid pipe (10) and a second refrigerant gas pipe (11) reciprocally connect between a second condenser (5) as a heat load side heat exchanger in 7) and a heating circuit ( 2) is formed, a first opening / closing valve (13) is interposed between the first and second refrigerant liquid pipes (8, 10), and the first and second refrigerant gas pipes (9, 9) are formed.
A second on-off valve (14) is provided between 11) to connect the two so that they can be opened and closed, and the total amount becomes the peak load of cooling in the cooling circuit (1) and the heating circuit (2). A building air-conditioning system that is filled with approximately the same amount of refrigerant. 2. A pipe line in the first refrigerant gas pipe (9) from the second opening / closing valve (14) to the air conditioning unit (7) and a pipe line to the first condenser (3). Between the highest branch portion (P ₁ ) and the refrigerant gas inlet port (29) of the first condenser (3), or in the first refrigerant liquid pipe (8), the first condenser (3 ) To the first on-off valve (13) and the uppermost branch portion (P ₂ ) of the pipeline to the air conditioning unit (7), and the refrigerant liquid flow of the first condenser (3). Exit (30)
The third opening / closing valve (15) on at least one of
The building air conditioning system according to claim 1, wherein the air conditioning system is provided.