JP6545378B2 - Air conditioning system and relay unit - Google Patents

Description

  The present invention relates to a technology for performing air conditioning in a building.

  In a water-based air conditioning system (for example, Patent Document 1) that performs air conditioning by circulating cold water or hot water in the indoor unit (for example, Patent Document 1), the heat source machine performs about 7 ° C. in summer (that is, cooling operation) and winter season (that is, heating operation) In the case, cold / hot water whose temperature is adjusted to about 45.degree. C. is generated and sent to the indoor unit.

  For example, in the cooling operation, the room temperature (room temperature) decreases by exchanging heat of 7 ° C. cold water with room air in the indoor unit. The temperature of the cold / hot water after heat exchange rises to about 12 ° C., and is returned from the indoor unit to the heat source unit.

  The indoor unit is provided with a flow control valve on the cold water flow side (the inlet side of the heat exchanger), and the air conditioning capacity is reduced by decreasing the water flow rate of the cold water as the room temperature approaches the set temperature. As a result, for example, the cold and warm water flowing into the indoor unit at 7 ° C. rises to a temperature higher than 12 ° C. and returns to the heat source unit. Thus, in recent years, from the viewpoint of energy efficiency, an air conditioning system aiming to reduce the transfer power of cold and hot water by reducing the amount of water flow as the air conditioning load decreases has become widespread.

Patent No. 4421783 gazette

  By the way, when the temperature of the cold / hot water subjected to heat exchange in the indoor unit rises to 20 ° C. or more in the cooling operation, a large temperature distribution occurs in the heat exchanger of the indoor unit. More specifically, the room air is cooled to a temperature close to 7 ° C. near the inlet in the water flow path of the heat exchanger, but can only be cooled to 20 ° C. near the outlet, and the air after heat exchange is The air at 7 ° C. and the air at 20 ° C. are mixed.

  In such a state, if the air in the room has a high humidity, the water vapor contained in the air at 20 ° C. is temporarily condensed by mixing with the air at 7 ° C., and is released as a water droplet into the room There is a possibility that a phenomenon (so-called dew skipping) may occur. In addition, when air at 20 ° C. intermittently touches the air outlet at around 7 ° C. at the air outlet of the indoor unit, condensation occurs in the vicinity of the air outlet and drops on the indoor floor surface (so-called ) May occur.

  The present invention was made in order to solve the above-mentioned subject, and an object of the present invention is to provide an air-conditioning system etc. which can prevent generating of a dew drop and a fly jump.

In order to achieve the above object, an air conditioning system according to the present invention is:
A heat source unit, a relay unit, and a first indoor unit and a second indoor unit connected to the relay unit;
The relay unit is
A parallel flow passage for guiding water from the heat source unit to the first indoor unit and the second indoor unit in parallel;
A series flow path for guiding the water to the first indoor unit and the second indoor unit in a predetermined order;
Switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path ,
The flow path is switched from the parallel flow path to the serial flow path when the temperature difference between the water returning to the heat source machine and the water flowing in from the heat source machine is equal to or greater than a predetermined threshold .

  According to the present invention, the relay unit includes a parallel flow path for guiding water from the heat source unit in parallel to the first indoor unit and the second indoor unit, and water from the heat source unit as the first indoor unit and the second indoor unit. And the switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path, so that the first indoor unit and In the second indoor unit, it is possible to prevent the occurrence of dew drop and fly fly.

It is a figure showing composition of an air-conditioning system concerning an embodiment of the present invention. It is a block diagram showing composition of a heat source machine. It is a block diagram which shows the structure of a relay machine. It is a figure which shows the relationship between a target value and a temperature deviation. It is a figure for demonstrating a parallel flow path. It is a figure for demonstrating a serial flow path. It is a figure for demonstrating switching of a parallel flow path and a serial flow path. It is a flow chart which shows the procedure of air conditioning control processing. It is a figure for demonstrating the serial flow path in other embodiment. It is a figure for demonstrating selection of the upstream indoor unit in a serial flow path. It is a figure which shows the structure of the air-conditioning system which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing the configuration of an air conditioning system according to an embodiment of the present invention. This air conditioning system is a system that performs air conditioning of a building such as an office building with cold water or hot water (hereinafter referred to as cold or hot water), and includes a heat source unit 1, a relay unit 2, and a plurality of indoor units 3 (indoor units 3a, The indoor unit 3 b), the temperature sensor 4, and the remote control 5 are provided.

The heat source unit 1 is connected to the relay unit 2 through the pipe 6, and sends cold / hot water whose temperature is adjusted by heat pump to the relay unit 2. As shown in FIG. 2, the heat source unit 1 includes a compressor 10, a four-way valve 11, a first heat exchanger 12, an expansion valve 13, a second heat exchanger 14, a fan 15, and a pump 16. , And the control board 17. The compressor 10, the four-way valve 11, the first heat exchanger 12, the expansion valve 13 and the second heat exchanger 14 are annularly connected to circulate a refrigerant such as CO ₂ or HFC (hydrofluorocarbon). A refrigerant circuit (also referred to as a refrigeration cycle circuit) is formed.

  The compressor 10 compresses the refrigerant to raise the temperature and pressure. The compressor 10 includes an inverter circuit that can change the capacity (delivery amount per unit) according to the drive frequency. The compressor 10 changes the drive frequency in accordance with a command from the control board 17.

  The four-way valve 11 is a valve for switching the circulation direction of the refrigerant. The four-way valve 11 is switched as shown by the solid line in FIG. 2 during the cooling operation. Thereby, the refrigerant circulates in the order of the compressor 10, the four-way valve 11, the first heat exchanger 12, the expansion valve 13 and the second heat exchanger 14. On the other hand, in the heating operation, the four-way valve 11 is switched as indicated by a broken line. Thereby, the refrigerant circulates in the order of the compressor 10, the four-way valve 11, the second heat exchanger 14, the expansion valve 13 and the first heat exchanger 12.

  The first heat exchanger 12 is, for example, a cross fin type fin-and-tube heat exchanger configured to perform heat exchange between the outside air and the refrigerant and configured by a heat transfer tube and a large number of fins.

  The fan 15 is, for example, a centrifugal fan or a multi-blade fan driven by a DC fan motor or the like, and supplies outside air to the first heat exchanger 12. The rotational speed of the fan 15, that is, the flow rate of the outside air supplied to the first heat exchanger 12 is changed in accordance with a command from the control board 17.

  The expansion valve 13 is a flow control valve for adjusting the flow rate of the refrigerant, and is, for example, an electronic expansion valve capable of adjusting the opening degree of the throttle by a stepping motor (not shown). Besides, as the expansion valve 13, a mechanical expansion valve, a capillary tube or the like in which a diaphragm is adopted in the pressure receiving portion may be adopted. The opening degree of the expansion valve 13 is changed in accordance with a command from the control board 17.

  The second heat exchanger 14 is a plate-type or double-pipe type heat exchanger, and performs heat exchange between the refrigerant and the hot and cold water.

  The pump 16 conveys the cold / hot water heat-exchanged by the second heat exchanger 14 to the relay unit 2. The pump 16 includes an inverter circuit, and the driving rotational speed is changed in accordance with a command from the control board 17. Thereby, the flow rate of the cold / hot water to be transported to the relay unit 2, that is, the water flow rate can be changed.

  The control board 17 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a communication interface, a readable / writable nonvolatile semiconductor memory (all not shown), and the like. Ru. The control board 17 communicably connects each of the compressor 10, the four-way valve 11, the expansion valve 13, the fan 15, and the pump 16 through a communication line (not shown). The control board 17 is communicably connected to the control board 28 of the relay 2 shown in FIG. 3 via a communication line (not shown).

  When the control board 17 receives an operation start command from the relay unit 2, the control board 17 controls the four-way valve 11 to switch the circulation direction of the refrigerant according to the type of the operation mode (cooling operation, heating operation). Further, the control board 17 controls each of the compressor 10, the expansion valve 13, and the fan 15 so that the hot and cold water supplied to the relay unit 2 has a predetermined set temperature according to the operation mode. In the present embodiment, the control board 17 controls the above-described components so that cold / hot water supplied to the relay unit 2 is 7 ° C. in the cooling operation and 45 ° C. in the heating operation.

  Further, the control board 17 adjusts the flow rate of the cold / hot water to be transported to the relay unit 2 by controlling the pump 16 based on the information on the water flow rate notified from the relay unit 2 during the cooling operation or the heating operation.

  The relay unit 2 is connected to the heat source unit 1 via the pipe 6 and connected to the indoor unit 3a and the indoor unit 3b via the pipe 7a and the pipe 7b. The relay unit 2 relays the cold / hot water supplied from the heat source unit 1 to the indoor unit 3a and the indoor unit 3b.

  As shown in FIG. 3, the relay unit 2 includes flow control valves 20 and 21, on-off valves 22 to 25, temperature sensors 26 a, 26 b and 27, and a control board 28. The flow rate adjustment valves 20 and 21 change the flow rate of the hot and cold water supplied to the indoor unit 3a and the indoor unit 3b according to the command from the control board 28. The on-off valves 22 to 25 are opened or closed in accordance with a command from the control board 28. The flow control valves 20 and 21 and the on-off valves 22 to 25 constitute switching means in the present invention.

  The temperature sensor 26a measures the temperature of the cold / hot water discharged from the indoor unit 3a (the outlet temperature of the indoor unit 3a). The temperature sensor 26b measures the temperature of the cold / hot water discharged from the indoor unit 3b (the outlet temperature of the indoor unit 3b). The temperature sensor 27 measures the temperature (inlet temperature) of the cold / hot water received from the relay unit 2. The temperature sensors 26a, 26b, 27 transmit data indicating the measured temperatures to the control board 28 at predetermined timing (for example, every predetermined time).

  The control board 28 includes a CPU, a ROM, a RAM, a communication interface, a readable and writable non-volatile semiconductor memory, and the like (none of which are shown). The control board 28 is communicably connected to the flow rate adjusting valves 20 and 21, the on-off valves 22 to 25 and the temperature sensors 26a, 26b and 27 through communication lines (not shown), and as described above The control board 17 is communicably connected via a communication line (not shown). Further, as shown in FIG. 1, the control board 28 is communicably connected to the temperature sensor 4 that measures the indoor air temperature (room temperature) through the communication line 8, and communicates with the remote control 5 through the communication line 9. Connect as possible.

  The control board 28 instructs the indoor unit 3a and the indoor unit 3b to start the operation and instructs the heat source unit 1 to start the cooling operation or the heating operation when the user performs an operation start operation through the remote control 5 . Further, the control board 28 controls the flow rate adjusting valves 20 and 21 and the on-off valves 22 to 25 to start supply of cold and hot water to the indoor unit 3a and the indoor unit 3b. Details of the operation of the relay unit 2 will be described later.

  The indoor unit 3a (for example, the first indoor unit) and the indoor unit 3b (for example, the second indoor unit) are air conditioners called a so-called fan coil unit, and the functions possessed by both are the same. As shown in FIG. 3, the indoor unit 3a (3b) includes a heat exchanger 30a (30b), a fan 31a (31b), and a control board 32a (32b).

  The heat exchanger 30a (30b) performs heat exchange between the cold / hot water supplied from the relay unit 2 and the indoor air. The fan 31a (31b) delivers the air after heat exchange into the room. The control board 32a (32b) includes a CPU, a ROM, a RAM, a communication interface, a readable / writable nonvolatile semiconductor memory, and the like (none of which are shown). The control board 32a (32b) starts or stops driving the fan 31a (31b) in accordance with a command from the control board 28 of the relay unit 2.

  Subsequently, the operation of the air conditioning system according to the present embodiment configured as described above will be described by taking the case of the cooling operation as an example.

  When the user performs a cooling operation start operation through the remote control 5, the remote control 5 outputs information indicating the start of the operation, the type of operation mode (here, cooling operation), and the set temperature (target temperature). The control data containing is transmitted to the control board 28 of the relay unit 2.

  When the control board 28 receives the control data from the remote controller 5, the control board 28 transmits control data including information indicating the start of operation and the type of operation mode to the control board 17 of the heat source device 1. As a result, the heat source unit 1 generates cold water at 7 ° C. and starts supplying the relay unit 2 with the cold water.

  Further, when the control board 28 receives the control data from the remote controller 5, it transmits control data including information indicating the start of operation to the control boards 32a and 32b of the indoor unit 3a and the indoor unit 3b. Thereby, the indoor unit 3a and the indoor unit 3b start driving of the fans 31a and 31b.

  The control board 28 has the temperature of the cold water (inlet temperature) measured by the temperature sensor 27, the temperature of the cold water measured by the temperature sensor 26a and the temperature sensor 26b (the outlet temperatures of the indoor unit 3a and the indoor unit 3b), and the temperature Based on the room temperature measured by the sensor 4 and the target temperature set by the user, the flow rate of cold water passing through the indoor unit 3a and the indoor unit 3b is adjusted.

  More specifically, the control board 28 is a temperature difference between the outlet temperature of the indoor unit 3a and the inlet temperature (first inlet / outlet temperature difference) and a temperature difference between the outlet temperature of the indoor unit 3b and the inlet temperature (second outlet temperature difference) The flow control valve 20, so that each of the target values is determined by the temperature deviation (.DELTA.Ta [K] = Tr-Ts) between the room temperature (Tr [.degree. C.]) and the target temperature (Ts [.degree. C]). Adjust the 21st aperture. FIG. 4 shows the relationship between the target value (ΔTw [K]) and the temperature deviation (ΔTa [K]).

  As shown in FIG. 4, since the case where the room temperature is 1 K or more higher than the target temperature is normal at the start of the cooling operation, ΔTw is determined to be 5 [K]. The cooling operation is continued, and as the room temperature approaches the target temperature, ΔTw is updated. As shown in FIG. 4, ΔTw = 9 [K] in ΔTa = 0 [K], and ΔTw = 13 [K] in ΔTa = −1 [K].

  The control board 28 switches the flow path of the cold water for passing water to the indoor unit 3a and the indoor unit 3b based on ΔTw in addition to the adjustment of the flow rate of the cold water as described above. The relay unit 2 has parallel channels (see FIG. 5) for guiding the cold water from the heat source unit 1 in parallel to the indoor unit 3a and the indoor unit 3b, and the cold water from the heat source unit 1 to the indoor unit 3a and the indoor unit 3b in advance. It is comprised so that switching with the serial flow path (refer FIG. 6) guide | induced in a defined order becomes possible.

  FIG. 7 is a view showing the relationship between ΔTw [K] and the flow path selected by the control substrate 28. From FIG. 7, it can be seen that the parallel flow path is selected when ΔTw = 5 [K], that is, the room temperature is high and the temperature difference from the target temperature is large. In addition, it is understood that the series flow path is selected when the room is sufficiently cooled and ΔTw = 10 [K].

(Cooling operation in parallel flow path)
At the start of the cooling operation (ie, ΔTa> 1 [K]), ΔTw = 5 [K], and the control board 28 selects the parallel flow path. At this time, the control board 28 performs control to open the on-off valves 22 and 23 and close the on-off valves 24 and 25. As a result, as shown in FIG. 5, the cold water flowing into the relay unit 2 is divided by the flow control valves 20 and 21 and sent to the indoor unit 3a and the indoor unit 3b, respectively. The split cold water is heat-exchanged with indoor air in the indoor unit 3a and the indoor unit 3b, and then joined in the relay unit 2 and returned to the heat source unit 1.

  Here, the flow rate adjusting valve 20 is controlled by the control board 28 so that the temperature difference (first inlet / outlet temperature difference) of the cold water measured by the temperature sensor 27 and the temperature sensor 26 a becomes ΔTw. Similarly, the flow rate adjustment valve 21 is controlled by the control substrate 28 so that the temperature difference (second inlet / outlet temperature difference) of the cold water measured by the temperature sensor 27 and the temperature sensor 26 b becomes ΔTw.

  The control board 28 notifies the control board 17 of the heat source unit 1 of the above control results of the flow rate adjustment valves 20 and 21 as information on the amount of water flow. As a result, the rotational speed of the pump 16 of the heat source unit 1 is adjusted such that the differential pressure across the flow control valves 20 and 21 becomes constant.

  When the cooling operation is continued under the control as described above, the room temperature decreases and eventually ΔTa falls below 1 [K]. Along with this, ΔTw rises from 5 [K] to 6 [K], 7 [K], and so on. As a result, the flow rate of cold water flowing through decreases, so the cooling capacity of the indoor unit 3a and the indoor unit 3b also gradually decreases.

(Cooling operation in series flow path)
When the room temperature continues to decrease and ΔTw continues to rise along with this and reaches 10 [K], as shown in FIG. 7, the control substrate 28 performs control to switch from the parallel flow path to the serial flow path. Specifically, the control board 28 performs control to close the flow control valve 21 and the on-off valve 22 and open the on-off valve 25. Thereby, as shown in FIG. 6, the cold water which flows in into the relay machine 2 is first sent to the indoor unit 3a via the flow control valve 20.

  The cold water heat-exchanged with indoor air by the heat exchanger 30a of the indoor unit 3a flows into the indoor unit 3b via the on-off valve 25. The cold water heat-exchanged with indoor air by the heat exchanger 30b of the indoor unit 3b is returned to the heat source unit 1 via the on-off valve 23. During operation in the serial flow path, the control substrate 28 adjusts the opening degree of the flow rate adjustment valve 20 based on the temperature difference (ΔTw) between the temperature sensor 27 and the temperature sensor 26 b to flow cold water Adjust the flow rate of

  FIG. 8 is a flow chart showing the procedure of the air conditioning control process executed by the control board 28 of the relay unit 2. The air conditioning control process is started by the user performing a cooling operation start or heating operation start operation through the remote controller 5 and ends the operation by the user performing a shutdown operation.

  The control board 28 instructs the indoor unit 3a and the indoor unit 3b to start operation (step S101). Thus, the fans 31a and 31b of the indoor unit 3a and the indoor unit 3b start driving.

  The control board 28 also instructs the heat source unit 1 to start the cooling operation or the heating operation (step S102). Thereby, the heat source unit 1 generates cold water of 7 ° C. in the cooling operation, generates hot water of 45 ° C. in the heating operation, and starts supply to the relay unit 2.

  The control board 28 opens the on-off valves 22 and 23, closes the on-off valves 24 and 25, and controls water flow to the indoor unit 3 a and the indoor unit 3 b in parallel flow paths (see FIG. 5) S103).

  Eventually, when the target value (ΔTw) described above reaches a predetermined value (for example, 10 [K] in the cooling operation), the control board 28 determines that switching to the serial flow path is necessary (step S104) YES, the flow control valve 21 and the on-off valve 22 are closed, the on-off valve 25 is opened, and water flow control to the indoor unit 3a and the indoor unit 3b is performed in the serial flow path (see FIG. 6) (step S105).

  Then, when ΔTw falls to a predetermined value (for example, 8 [K] in the cooling operation), the control board 28 determines that switching to the parallel flow path is necessary (step S106; YES), and the flow rate adjustment The valve 21 and the on-off valve 22 are opened, the on-off valve 25 is closed, and water flow control to the indoor unit 3a and the indoor unit 3b is performed in the parallel flow path (see FIG. 5) (step S103). Thereafter, the control board 28 repeatedly executes the process of steps S103 to S106 described above until the operation of the operation stop is performed by the user.

  As described above, in the air conditioning system according to the embodiment of the present invention, the relay unit 2 sets the temperature difference between the chilled water returning to the heat source unit 1 and the chilled water flowing from the heat source unit 1 to a predetermined threshold (10 [K]) When it becomes more than, it switches from a parallel flow path to a serial flow path, and performs water flow control to the indoor unit 3a and the indoor unit 3b. As a result, the temperature distribution in one indoor unit can be suppressed to 10 [K] or less, and it is possible to prevent the occurrence of so-called dripping or flying.

  The indoor unit 3a and the indoor unit 3b may have a simple configuration of driving the fans 31a and 31b at a fixed number of revolutions regardless of the type of the operation mode when receiving the operation start command. Therefore, as the indoor unit 3a and the indoor unit 3b, not a dedicated air conditioner but an air conditioner of a fan coil unit that generally circulates can be adopted, and the versatility is excellent.

  The present invention is not limited to the above embodiment, and various modifications can of course be made without departing from the scope of the present invention.

  For example, the relay unit 2 may perform control to lower the blowing capacity of the upstream indoor unit (the indoor unit 3a) compared to the downstream indoor unit (the indoor unit 3b) in the air conditioning operation in the serial flow path. . Hereinafter, this control will be described.

  In the air conditioning operation in the serial flow path, the temperature difference between the indoor air and the cold and warm water is larger in the upstream indoor unit (the indoor unit 3a) than in the downstream indoor unit (the indoor unit 3b) Thus, the air conditioning capacity of the indoor unit 3a is also larger. Then, temperature distribution may occur in indoor air, which may cause the user to feel uncomfortable. Therefore, by reducing the air blowing capacity of the indoor unit 3a, the difference between the air conditioning capacities of the indoor unit 3a and the indoor unit 3b is reduced.

  Specifically, when instructing the indoor unit 3a and the indoor unit 3b to start the operation, the control board 28 of the relay unit 2 adds the information indicating the start of the operation to the indoor unit 3a which is the indoor unit on the upstream side. And transmit control data including information for instructing a decrease in blowing capacity. As a result, the indoor unit 3a can lower the capacity of the fan 31a than usual and drive the fan 31a to reduce the blowing capacity.

  In general, the efficiency of heat exchange is improved by reducing the blowing capacity as described above, so that in the cooling operation, the effect of increasing the latent heat treatment capacity (latent heat ratio) is obtained compared to the operation in the parallel flow path. Such an effect is particularly effective in the rainy season when the cooling load is not relatively high but the humidity is high.

  Further, the relay unit 2 may be appropriately selected according to the condition of the air conditioning load, etc., whichever of the indoor unit 3a and the indoor unit 3b should be on the upstream side in the serial flow path.

  FIG. 9 is a diagram showing a serial flow path when the indoor unit 3b is selected on the upstream side. In this case, the control board 28 performs control to close the flow control valve 20 and the on-off valves 23 and 25 and open the on-off valves 22 and 24. Thereby, the cold / hot water flowing into the relay unit 2 is first sent to the indoor unit 3 b via the flow rate adjustment valve 21.

  The cold / hot water subjected to heat exchange with indoor air by the heat exchanger 30b of the indoor unit 3b flows into the indoor unit 3a via the on-off valve 24. The cold / hot water subjected to heat exchange with indoor air by the heat exchanger 30a of the indoor unit 3a is returned to the heat source unit 1 via the on-off valve 22. In addition, at the time of operation in this serial flow path, the control substrate 28 adjusts the throttle opening degree of the flow rate adjustment valve 21 based on the temperature difference (ΔTw) between the temperature sensor 27 and the temperature sensor 26a to supply water. Adjust the flow rate of cold and hot water.

  For example, as shown in FIG. 10, it is assumed that the indoor unit 3a is installed in the perimeter zone of one office building and the indoor unit 3b is installed in the interior zone. In such a situation, the heat load from the perimeter zone is increased by the heat loss from the outer wall and the window at night in winter. Therefore, the relay unit 2 performs water flow control in a serial flow path with the indoor unit 3a on the upstream side. As a result, the perimeter zone is heated by the 45 ° C. hot water supplied from the heat source unit 1, and the interior zone is heated by the hot water whose temperature is lowered to about 40 ° C.

  On the other hand, when there is the influence of solar radiation in the winter daytime, the heating load in the perimeter zone is low, so the indoor unit 3b is selected upstream. Thereby, the interior zone is heated by the 45 ° C. hot water, and the perimeter zone is heated by the approximately 40 ° C. hot water.

  As described above, since the upstream side and the downstream side are selected according to the condition of the air conditioning load in the space to be air-conditioned, which each indoor unit bears, it is possible to suppress local overheating or excessive cooling indoors.

  Further, as shown in FIG. 11, in the air conditioning system, relay units 2a and 2b having the same function as the relay unit 2 are connected in series to the heat source unit 1, and the indoor unit 3a and the indoor unit 3b are connected to the relay unit 2b. The indoor unit 3c may be connected to the relay unit 2a. The indoor unit 3c is a radiation panel. In this configuration, when the air conditioning operation is started, the relay unit 2a performs water flow control in a series flow path for guiding cold water from the heat source unit 1 in order of the relay unit 2b to the indoor unit 3c, and the relay unit 2b The water flow control is performed in a serial flow path for guiding the cold and hot water from the relay unit 2a in order of the indoor unit 3a to the indoor unit 3b.

  In the case of the cooling operation in the above configuration, the temperature of the cold water flowing from the heat source unit 1 at 7 ° C. rises to about 12 ° C. in the indoor unit 3 a and further rises to about 17 ° C. in the indoor unit 3 b. 3c (radiation panel) to cool the room further.

  Thereby, the temperature of the cold water returning to the heat source unit 1 becomes close to room temperature. That is, the amount of cooling heat which can be taken out of the cold water generated by the heat source unit 1 can be utilized to the maximum. In this case, dew condensation can be prevented from occurring in the indoor unit 3c by adjusting the flow rate of the cold water so as to reach the dew point of the air in the room at the stage of flowing into the indoor unit 3c.

  The present invention is capable of various embodiments and modifications without departing from the broad spirit and scope. In addition, the embodiment described above is for describing the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is indicated not by the embodiments but by the claims. And, various modifications applied within the scope of the claims and the meaning of the invention are considered to be within the scope of the present invention.

  The present invention can be suitably adopted in an air conditioning system that performs air conditioning in a building by a water system.

  Reference Signs List 1 heat source unit, 2, 2a, 2b relay unit, 3a to 3c indoor unit, 4, 26a, 26b, 27 temperature sensor, 5 remote control, 6, 7a, 7b piping, 8, 9 communication line, 10 compressor, 11 square Valve, 12 first heat exchanger, 13 expansion valve, 14 second heat exchanger, 15 fan, 16 pump, 17, 28, 32a, 32b control board, 20, 21 flow control valve, 22 to 25 on-off valve, 30a , 30b heat exchanger, 31a, 31b fan

Claims (6)

A heat source unit, a relay unit, and a first indoor unit and a second indoor unit connected to the relay unit;
The relay unit is
A parallel flow passage for guiding water from the heat source unit to the first indoor unit and the second indoor unit in parallel;
A series flow path for guiding the water to the first indoor unit and the second indoor unit in a predetermined order;
Switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path ,
An air conditioning system, wherein the flow path is switched from the parallel flow path to the serial flow path when a temperature difference between water returning to the heat source machine and water flowing in from the heat source machine is equal to or greater than a predetermined threshold . A heat source unit, a relay unit, and a first indoor unit and a second indoor unit connected to the relay unit;
The relay unit is
A parallel flow passage for guiding water from the heat source unit to the first indoor unit and the second indoor unit in parallel;
A series flow path for guiding the water to the first indoor unit and the second indoor unit in a predetermined order;
Switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path,
Among prior Symbol the second indoor unit with the first indoor unit, reduce than other blowing capacity the blowing capacity of the person who the water is introduced first in the series flow path, air-conditioning systems. A heat source unit, a relay unit, and a first indoor unit and a second indoor unit connected to the relay unit;
The relay unit is
A parallel flow passage for guiding water from the heat source unit to the first indoor unit and the second indoor unit in parallel;
A series flow path for guiding the water to the first indoor unit and the second indoor unit in a predetermined order;
Switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path,
In accordance with the air-conditioning load of the air-conditioning target space corresponding to respective front Symbol first indoor unit and the second indoor unit, determines the order in which directing said water in said series flow path, air-conditioning systems. A parallel flow passage for guiding water from the heat source unit to the first indoor unit and the second indoor unit in parallel;
A series flow path for guiding the water to the first indoor unit and the second indoor unit in a predetermined order;
Switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path ,
The relay according to claim 1 , wherein the flow path is switched from the parallel flow path to the serial flow path when a temperature difference between water returning to the heat source machine and water flowing in from the heat source machine is equal to or greater than a predetermined threshold . A parallel flow passage for guiding water from the heat source unit to the first and second indoor units in parallel;
A series flow path for guiding the water to the first indoor unit and the second indoor unit in a predetermined order;
Switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path,
It said first indoor unit and of the second indoor unit, the air blowing ability of the person who the water is introduced earlier in the series flow path is lower than the other blowing capacity, splicing machine inside. A parallel flow passage for guiding water from the heat source unit to the first indoor unit and the second indoor unit in parallel;
A series flow path for guiding the water to the first indoor unit and the second indoor unit in a predetermined order;
Switching means for switching the water flow path from the parallel flow path to the serial flow path and from the serial flow path to the parallel flow path,
In accordance with the air-conditioning load of the air-conditioning target space corresponding to each of the first indoor unit and the second indoor unit, determines the order in which directing said water in said series flow path, relay device medium.

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