JP2008020168A - Air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning system capable of securing a going-returning temperature difference to operate an air conditioner, without increasing the number of coil lines of a heat exchanger even when an outside air temperature comes to a prescribed temperature or less, under a cooling operation condition in an intermediate period or a winter season, in the air conditioning system of supplying the heating medium from a heat source facility to the heat exchanger and of returning the heating medium to the heat source facility after heat-exchange. <P>SOLUTION: This air conditioning system of supplying the heating medium from the heat source facility to the heat exchanger and of returning the heating medium to the heat source facility after heat-exchange is provided with the first passage for mixing the outdoor outside air with the returning air from an indoor side to be fed to the heat exchanger, and the second passage for bypassing the outside air to be fed to a fan, without passing the heat exchanger, a switching means is provided to allow switching between the first passage and the second passage, the first passage is opened by the switching means and the second passage is blocked, when the outside air temperature comes to the prescribed temperature or more, under the cooling operation condition, and the first passage is blocked by the switching means and the second passage is opened, when the outside air temperature gets to the prescribed temperature or less. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air conditioning system that harmonizes air, and particularly relates to an air conditioning system that supplies a heat medium such as water from a heat source facility to a heat exchanger, and returns the heat medium to the heat source facility after heat exchange. The present invention relates to an air-conditioning system that is cooled during the intermediate period or winter season.

Conventionally, as an air conditioning system capable of exchanging heat or cold water or hot water sent from a heat source facility through a return pipe with a supply air and returning water to the heat source facility through a return water pipe, a district heat supply system or There is a separate heat source system.
In the district heat supply facility, a central air-conditioning system is used to supply the district heat medium sent from the heat source facility directly to the consumer side. However, with this central air-conditioning method, the return water temperature must be kept constant. I must. That is, in order to efficiently operate the heat source device, it is important to keep the return water temperature constant, and the same is known in the case of an individual heat source system.
For this reason, a bleed-in circuit around the heat source has been developed in order to ensure a constant return water temperature. For example, as disclosed in Patent Documents 1 and 2, the return water temperature difference is kept constant, In order to reduce the conveyance power of the heat source type air conditioning system, the circulating pump controls the circulation flow rate in the heat exchanger by supplying a part of the return water to the inlet of the heat exchanger by the circulation pump to keep the return water temperature difference constant. I have to.
JP-A-9-166346 JP 2006-84142 A

By the way, in the air conditioning system that can supply the outgoing water as the heat medium from the heat source equipment to the heat exchanger via the outgoing water pipe and return the water to the heat source equipment through the return water pipe, the summer is of course the intermediate period In some cases, it may be cooled in winter. In order to maintain the air conditioner in the intermediate or winter season, for example, to maintain the room temperature at about 23 ° C, the air supply SA temperature of the air conditioner must be about 14 ° C because there are heat sources such as people and personal computers in the room. The room temperature of 23 ° C. must be returned to the air conditioning system for cooling. At this time, in the air conditioning system, in order to reduce the load on the heat source equipment, it is required to maintain a constant temperature difference between the outgoing water temperature and the return water temperature. For this reason, the return water temperature returned to the heat source equipment is required. Must be maintained at a constant temperature.
This will be described with reference to FIG. 2. In the air conditioning system a, the outgoing water is supplied from the outgoing water pipe 1 to the heat exchanger b from the heat source equipment, and the returning water is returned from the returning water pipe 2 to the heat source equipment after the heat exchange. For example, in the air conditioning system a that requires a return water temperature of 7 ° C. and a return water temperature of 14 ° C., the room temperature is maintained at, for example, about 23 ° C. even when cooling in the intermediate period or winter season is performed. Therefore, since there are heat sources such as humans and personal computers in the room, the air supply (SA) supplied to the room from the air conditioner must be about 14 ° C.

Assuming that the supply air temperature SA is 14 ° C. and the actual room temperature is 23 ° C., when the outside air OA temperature becomes a low temperature (for example, 10 ° C.) lower than the predetermined temperature, When the heat exchanger c having a coil array is mixed with the return air RA from the heat exchanger c, the air temperature at the suction port a1 where the outside air OA (10 ° C.) and the return air RA (23 ° C.) are mixed is The return water temperature is lower than the required return water temperature of 14 ° C. than the return air RA (23 ° C.), and the difference from the required return water temperature of 14 ° C. is reduced, so that the water temperature passing through the heat exchanger c is It becomes difficult to raise the desired return water temperature tw4 from 14 to ℃ from temperature tw3 (for example, 7 ℃).
That is, the temperature difference between the target temperature of the return water and the air entering the heat exchanger c is reduced, and the temperature of the air passing through the heat exchanger c is, for example, 23 ° C and 15 ° C. When the temperature is raised to 14 ° C, in order to raise the return water temperature to 14 ° C with the passing air of 15 ° C, the coil array of the heat exchanger c is increased as compared with 23 ° C (the heat exchange performance is increased). Otherwise, the return water temperature cannot be raised to the desired 14 ° C. The conditioned air from the fan f is supplied from the supply port a2 to the room to be air-conditioned as the supply air SA, but the temperature value signal of the temperature sensor T near the supply port a2 is input to the control device TC, The amount of water from the heat source equipment is controlled by the flow rate control valve b provided in the return water pipe 2 by the control device TC so that the supply air SA temperature becomes a desired level of about 14 ° C.

  In this way, in the air conditioning system that can supply the outgoing water from the heat source equipment to the heat exchanger via the outgoing water pipe and return the water to the heat source equipment through the return water pipe, the cooling is performed in the intermediate period or winter season In order to increase the return water temperature to a predetermined temperature in order to ensure a difference in return temperature when the outside air becomes a low temperature below a predetermined temperature, it is necessary to increase the number of coil rows of the heat exchanger, As a result, there is a problem that the apparatus becomes large and expensive because the number of parts increases.

  The present invention has been made in view of the above problems, and in an air conditioning system that supplies a heat medium from a heat source facility to a heat exchanger and returns the heat medium to the heat source facility after heat exchange, cooling in an intermediate period or winter season is performed. To provide an air conditioning system capable of operating an air conditioner while ensuring a difference in return temperature without increasing the number of coil rows of a heat exchanger even when outside air falls below a predetermined temperature in a state where the air conditioner is made It is in.

In order to solve the above problems, the invention of claim 1 is an air conditioning system in which a heat medium from a heat source facility is supplied to a heat exchanger and the heat medium is returned to the heat source facility after heat exchange. A switching means for switching between the first passage and the second passage by providing a first passage for mixing with the air and sending it to the heat exchanger and a second passage for sending outside air to the fan by bypassing the heat exchanger When the outside air is at a predetermined temperature or higher in the state of cooling, the switching means opens the first passage and shuts off the second passage, and when the outside air is below the predetermined temperature. The air conditioning system is characterized in that the first passage is blocked by the switching means and the second passage is opened.
The invention of claim 2 is the temperature difference of the heat medium at the inlet / outlet, wherein a circulation pump is provided between the connecting pipe connected to the inlet of the heat exchanger and the connecting pipe connected to the outlet. Is an air conditioning system characterized by combining a bleed-in circuit with a predetermined value.

According to the invention of claim 1, in the air conditioning system that supplies the heat medium from the heat source facility to the heat exchanger and returns the heat medium to the heat source facility after the heat exchange, the outside air is in a state of being cooled in the intermediate period or winter season. Even if the temperature is lower than the predetermined outside air temperature, the air conditioner can be operated while ensuring a return temperature difference without increasing the number of coil rows of the heat exchanger.
According to a second aspect of the invention, in the first aspect of the invention, a circulation pump is provided between the connection pipe connected to the inlet and the connection pipe connected to the outlet of the heat exchanger, and the medium of the forward ring By combining a bleed-in circuit so that the temperature difference becomes a predetermined value, the burden on the heat source facility can be reduced.

A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an overall outline of the first embodiment. In FIG. 1, a district heat supply system or an individual heat source system is used to send power from a heat source facility. The heat medium to be used is directly or via a heat exchanger and water is used as the heat medium, and the heat medium is supplied to each heat exchange system by the installed forward water pipe 1 and return water pipe 2. An embodiment of a plurality of heat exchange systems connected to the return water pipe 2 is illustrated.
In the present embodiment, the main body 3 of the heat exchange system (air conditioning system) is first provided with a suction port 31 that sucks in the return air RA or a mixture of the return air RA and the outside air OA, and sucks in air to be conditioned, A heat exchanger 4 comprising a plurality of coil arrays is provided upstream of the fan 5 downstream of the suction port 31, the forward water pipe 1 is connected to the inlet of the heat exchanger 4, and the return water pipe 2 is heat exchanged. A heat medium (cooled / warm water) connected to the heat medium outlet of the vessel 4 and sent from the heat source equipment is supplied to the heat exchanger.

The upstream of the air passage (duct) 6 of the outside air OA is opened to the outside air, and the downstream is divided into two forks, but one of the forked air passages 61 (first passage) of the return air RA is mixed with the return air RA. The other air passage 62 (second passage) is connected to an air suction port 32 provided between the heat exchanger 4 and the fan 5 and is divided into two branches. In the middle of each air passage 61, 62, dampers 611 (MD1), 621 (MD2) for passing / blocking air or adjusting the amount of air are provided, and these dampers 611, 621 are outdoor temperature sensors. The open / close state is controlled via the control device TC3 by the temperature value signal from T3.
In addition, a value signal of the temperature detected by the temperature sensor T1 provided at the supply port 33 to the room to be air-conditioned is input to the control device TC1, and a two-way valve (provided in the return water pipe 2 by the control device TC1) MV1) 8 is controlled so that the temperature of the supply air (SA) is controlled to a predetermined temperature, and the conditioned air blown from the fan 5 through the heat exchanger 4 is supplied from the supply port 33 to the supply air SA. Is supplied to a room to be air-conditioned via a duct.

  As shown in FIG. 1, a bleed-in circuit 9 is incorporated in the main body 3 in this heat exchange system, and this bleed-in circuit 9 is connected to a water supply pipe 1 and a return water pipe 2 connected to a heat source facility. A two-way valve (MV2) 92 that bypasses the outgoing water from the heat source from the outgoing water pipe 1 to the returning water pipe 2 and a variable speed circulation pump 91 that circulates from the returning water pipe 2 to the outgoing water pipe 1 are provided. The detected temperature value signal of the temperature sensor T2 provided in the vicinity of the outlet of the outgoing water pipe 1 is input to the control device TC2, which is connected to the two-way valve (MV2) 92 and the variable speed circulation pump 91. The number of revolutions is controlled via an inverter (INV).

[Activation]
Next, the operation of the above configuration will be described. In FIG. 1, in order to maintain the room temperature at about 20 to 26 ° C., there is a heat source such as a human being or a personal computer in the room. SA) The temperature must be about 10 ° C. below room temperature. At this time, in the air conditioning system, in order to reduce the load of the heat source equipment, it is required to maintain a constant temperature difference between the outgoing water temperature and the return water temperature. For example, the outgoing water temperature is 7 ° C. Assuming that the ideal return water temperature is set to 14 ° C., the air conditioning system 3 is required to maintain the return water temperature at 14 ° C. returned to the heat source equipment.

(1) As described above, the cooling operation is performed even in the intermediate period or winter season. However, if the temperature value signal from the outdoor temperature sensor T3 is higher than a predetermined temperature (for example, 15 ° C.) in the cooling state. For example, the damper 611 (MD1) as the switching means is opened, and one of the two air passages 61 (first passage) as the first passage communicates with the air passage 7 of the return air RA, and the switching means. The damper 621 (MD2) is cut off and the air passage 62 is also cut off.
Therefore, the outside air of 15 ° C. or higher and the return air RA of usually about 20 ° C. to 26 ° C. are mixed and sent to the heat exchanger 4 from the suction port 31. The temperature of the mixed air is a set temperature required for the return water temperature. The return water temperature can be raised to about 14 ° C. in the process of passing through the heat exchanger 4 even during normal operation.
In addition, the air temperature obtained by mixing the outside air (OA) and the return air (RA) is also input to the control device TC1 by the temperature value signal of the temperature sensor T1 in the vicinity of the supply port 33, and is supplied to the return water pipe 2 by the control device TC1. The amount of water from the heat source facility is controlled by the provided flow control valve 8 so that the supply air SA temperature becomes a desired temperature (for example, about 14 ° C.).

(2) If the temperature value signal from the outdoor temperature sensor T3 is not higher than a predetermined temperature (for example, 15 ° C.) in the air-cooled state, the damper 611 (MD1) as the switching means is shut off. The bifurcated air passage 61 that is the first passage is blocked, the damper 621 (MD2) that is the switching means is opened, the air passage 62 (second passage) is communicated, and the outside air (OA) is directly It is supplied to an air inlet 32 provided downstream of the heat exchanger 4.
Accordingly, only about 20 ° C. to 26 ° C. of the return air RA is supplied to the heat exchanger 4, and the temperature of the air of the return air RA is about 20 ° C. to 26 ° C., so the set temperature required for the return water temperature (for example, 14 The return water temperature can be increased to about 14 ° C. in the process of passing through the heat exchanger 4.
On the other hand, the outside air (OA) that bypasses the heat exchanger 4 and is supplied upstream of the fan 5 is mixed with the conditioned return air (RA), and is supplied to the room to be air-conditioned from the supply port 33 by the fan 5. At this time, the temperature value signal of the temperature sensor T1 in the vicinity of the supply port 33 is input to the control device TC1, and the control device TC1 controls the amount of water from the heat source facility with the flow rate control valve 8 provided in the return water pipe 2. The supply SA temperature is set to a desired temperature (for example, about 14 ° C.).

(3) In the present embodiment, even in the above-described configuration, even if the outside air becomes below the predetermined outside air temperature in the state where the cooling is performed in the intermediate period or winter season, the number of coil rows of the heat exchanger is not increased. Although the return temperature difference can be ensured, the bleed-in circuit 9 can be installed to operate more effectively.
The bleed-in circuit 9 is provided between the heat source equipment (not shown) and the main body 3, but normally the two-way valve (MV2) 92 is closed, and the water flow from the heat source equipment is heat exchanged from the water supply pipe 1. All the water that is supplied to the vessel 4 and is a heat medium returns to the heat source facility via the return water pipe 2 after heat exchange. However, if the temperature value signal of the temperature detected by the temperature sensor T2 provided near the outlet of the outgoing water pipe 1 does not reach the predetermined temperature difference, the control device TC2 opens the two-way valve (MV2) 92 and is allowed. The variable speed circulation pump 91 is operated, and the return water discharged from the heat exchanger 4 passes through the variable speed circulation pump 91 and is returned to the inlet of the heat exchanger 4 again to reach a predetermined temperature at which return water is required. Circulate until. At this time, the rotational speed of the variable speed circulation pump 91 is controlled via an inverter (INV), and the amount of circulating water is adjusted so as to achieve an appropriate return water temperature.
Therefore, (2) the response speed can be increased as necessary, and the amount of water supplied from the heat source facility can be omitted.

As described above, in Example 2 described above, in the air conditioning system that supplies the heat medium from the heat source facility to the heat exchanger and returns the heat medium to the heat source facility after heat exchange, in the state of being cooled in the intermediate period or winter season Even when the outside air temperature falls below the predetermined outside air temperature, the air conditioner can be operated with the difference in return temperature without increasing the number of coil rows of the heat exchanger, and connected to the inlet of the heat exchanger. Combines a bleed-in circuit with a circulation pump between the connecting pipe connected to the outlet and the connecting pipe connected to the outlet so that the temperature difference of the water in the heating medium is efficiently set to a predetermined value, reducing the burden on the heat source equipment To do.
Of course, the present invention is not limited to the above-described embodiments as long as the features of the present invention are not impaired. For example, although the air conditioning system is combined with a bleed-in circuit, it may be applied to the air conditioning system of the conventional example (FIG. 1) or may be applied to an air conditioning system with an individual heat source system.

It is a systematic diagram of the air-conditioning system of the Example of this invention. It is a systematic diagram of the conventional air conditioning system.

Explanation of symbols

1 ... Outbound piping, 2 ... Return water piping,
3 ... Heat exchange system (air conditioning system) body, 31, 32 ... Air intake port, 33 ... Supply port,
4 ... heat exchanger, 5 ... fan,
6, 61, 62 ... outside air (OA) air passage, 611, 621 ... damper 7 ... return air (RA) air passage,
8 ... Two-way valve (fluid control valve),
9 ... Bleed-in circuit, 91 ... Variable speed circulating pump, 92 ... Two-way valve,
T1, T2, T3 ... Temperature sensor, TC1, TC2, TC3 ... Control device
INV ... Inverter

Claims (2)

In an air conditioning system that supplies the heat medium from the heat source equipment to the heat exchanger and returns the heat medium to the heat source equipment after the heat exchange,
A first passage that mixes outdoor outdoor air with the return air from the room and sends it to the heat exchanger; and a second passage that sends outside air to the fan by bypassing the heat exchanger, and the first passage, Switching means for switching the second passage is provided;
When the outside air is at a predetermined temperature or higher in the air-cooled state, the switching means opens the first passage and shuts off the second passage,
An air conditioning system characterized in that when the outside air is below a predetermined temperature, the switching means shuts off the first passage and opens the second passage.   In Claim 1, a circulation pump is provided between the connection pipe connected to the inlet and the connection pipe connected to the outlet of the heat exchanger so that the temperature difference of the heat medium at the inlet / outlet becomes a predetermined value. Air conditioning system characterized by a combination of a bleed-in circuit.

Images