JPH068432Y2 - Air conditioning system controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention mainly relates to a control device for an air conditioning system for a store in which a large number of refrigerating / refrigerating showcases such as in a supermarket are installed.

(Prior art) In a supermarket with a large store area, a large center heat pump is installed in a separate room from which hot water and brine are supplied to each terminal heat pump, and the specified hot air or cold air is blown from the outlet of each ceiling side indoor unit. Is sent.

However, since many open-type freezer / refrigerator showcases are installed in the store, cold aisle is generated around the floor due to leakage of cold air from the showcases, and the showcase is constantly cooled.

Conventionally, in order to mitigate the condition of this cold aisle, a duct is formed along the bottom, back and top of the showcase, and a reheater and a blower are installed in the duct, and a duct near the ceiling is installed through the duct. There is one that takes in warm air and reheats it to guide it to the bottom of the showcase.

(Problems to be solved by the invention) In the above air conditioning system, when the temperature of the brine rises as the indoor cooling operation rate increases, the operation rate of the center heat pump is increased. There was a problem that

The object of the present invention is to use the warm air in the upper part of the room to relax the cold aisle when the temperature of the brine is below a predetermined limit, and to use the cold air of the cold aisle when the temperature rises above a certain limit. Another object of the present invention is to provide an energy-saving air conditioning system that lowers the temperature of brine and alleviates cold aisle.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a center heat pump that forms a brine at a constant temperature, and a plurality of terminal heat pumps that are connected to the center heat pump via brine pipes, respectively. A plurality of ceiling side indoor units that are connected to each terminal heat pump on one side via a refrigerant pipe to send conditioned air to the room, and are connected to each terminal heat pump on the other side via a refrigerant pipe to add air taken in from the upper part of the room In a controller of an air-conditioning system having a showcase-side indoor unit that warms and blows air to the bottom of the showcase to mitigate cold aisles on the floor, a temperature sensor that detects the temperature of the brine, and an upper limit temperature and a lower limit temperature of the brine. When the temperature detected by the temperature sensor exceeds the upper limit temperature, the direction of air blown by the indoor unit on the showcase side is changed. Control means is provided to switch from the lower part of the showcase to the upper part of the room, and to switch the air blowing direction from the upper part of the room to the lower part of the showcase when the temperature becomes lower than the lower limit temperature.

(Operation) According to the present invention, when the temperature of the brine is lower than or equal to the lower limit temperature, the blowing direction of the indoor unit on the showcase side is switched from the upper part of the room to the lower part of the showcase, and thereafter, the warm air is heated from the upper part of the room. It is inhaled, heated, and sent to the bottom of the showcase to relieve cold aisle on the floor. The heat source for this heating is supplied from the brine via the refrigerant of the other terminal heat pump. Then, when the temperature of the brine becomes equal to or higher than the upper limit temperature, the air blowing direction is switched to the opposite direction to the above, and thereafter, cool air is sucked from the lower part of the showcase to be heated and sent to the upper part of the room. The heat source for this heating is supplied from the brine via the refrigerant of the other terminal heat pump.

(Embodiment) FIG. 1 is a block diagram of an air conditioning system showing an embodiment of the present invention, and FIG. 2 is a circuit diagram of the air conditioning system.

Reference numeral 1 denotes a showcase, which has a duct 2 formed on the back and bottom thereof, and an intake / exhaust port 3 at the bottom thereof.

This air conditioning system is composed of a center heat pump 4, a brine pipe 5, a plurality of terminal heat pumps 6, 7, a ceiling side indoor unit 8, a showcase side indoor unit 9, a control unit 10, a temperature sensor 11, a duct 2 and the like. .

The center heat pump 4 is installed in a machine room or the like outside the store to form brine or hot water having a constant temperature, and the brine is sent to each terminal heat pump 6, 7 through the brine pipe 5 by the circulation pump 12.

Each of the terminal heat pumps 6 for exchanging heat between the brine and the refrigerant is installed on the ceiling 13 (behind the ceiling), and has a compressor 14, a four-way valve 15, as shown in FIG.
It is composed of a heat exchanger 16 and an expansion valve 17. The ceiling-side indoor unit 8 is connected to the terminal heat pump 6 via the refrigerant pipe 18.
The heat exchanger 19 and the blower 20 are provided inside.

Therefore, during cooling, as shown in FIG. 2, the refrigerant flows through the four-way valve 15 in the direction of the solid line arrow to radiate heat in the heat exchanger 16 and absorb heat in the heat exchanger 19 to cool air from the ceiling side indoor unit 8 into the store. Is supplied. Further, at the time of heating, the four-way valve 15 of the terminal heat pump 6 is switched, the refrigerant flows in the direction of the arrow indicated by the broken line, the heat exchanger 19 radiates heat, and the heat exchanger 16 absorbs heat, causing hot air to flow from the ceiling side indoor unit 8 into the store. Supplied.

Each of the other terminal heat pumps 7 is installed above the ceiling above the showcase 1 and connected to the center heat pump 4 via a brine pipe 5, and its internal circuit is the same as that of the terminal heat pump 6 described above. That is, it is composed of a compressor 21, a four-way valve 22, a heat exchanger 23, and an expansion valve 24. The four-way valve 22 normally switches the flow of the refrigerant in the direction of the solid line arrow to perform the warming operation by the showcase side indoor unit 9 described later, and switches to the direction of the broken line arrow to perform the cooling operation as necessary.

The showcase-side indoor unit 9 is installed above the showcase 1. FIG. 3 is a sectional view of a main part of the showcase-side indoor unit 9. The showcase side indoor unit 9 includes a reheater 26 and a blower 27 inside a plenum chamber 25 that covers the outside.
The reheater 26 is connected to the terminal heat pump 7 via the refrigerant pipe 28. Also, the plenum chamber 25
The intake hoses 29a, 29b and the exhaust hoses 30a,
30b is connected to the intake hose 29a and the exhaust hose 30.
An exhaust hose 30 a and an intake hose 29 b are connected to the duct 2 at the intake / exhaust port 32 attached to the down wall 31. Further, the dampers 33 and 34 that perform a switching operation by a drive mechanism (not shown) are provided.
34 is rotated to the state of the solid line or the chain double-dashed line in FIG. 3 so that the wind direction can be switched.

Therefore, when the dampers 33 and 34 are in the solid line state, the air in the upper part of the store is sucked from the intake / exhaust port 32, discharged from the intake / exhaust port 3, and mixed with the cold aisle on the floor A. Then, in the two-dot chain line state, the cold air of the cold aisle is sucked from the intake / exhaust port 3 and discharged from the intake / exhaust port 32.

The temperature sensor 11 is attached to the brine pipe 5 between the center heat pump 4 and each of the terminal heat pumps 6 and 7, and detects the temperature T _S of the brine.

The control unit 10 is composed of a microcomputer, controls the center heat pump 4, and drives a drive mechanism to switch the dampers 33 and 34 based on the detected temperature T _S of the brine detected by the temperature sensor 11 as described later. Control. The control unit 10 controls the detected temperature T _S
For, the upper limit temperature T _H and the lower limit temperature T _L that is 0.5 ° C. lower than the upper limit temperature T _H are set.

Next, the operation of the showcase side indoor unit 9 of this air conditioning system will be described. FIG. 4 is a flow chart showing the operation.

The center heat pump 4 and the circulation pump 12 are operated,
It is assumed that the brine circulates in the brine pipe 5 and that one terminal heat pump 6 is in the cooling operation by switching the four-way valve 15. And the other terminal heat pump 7
It is assumed that the four-way valve 22 is switched to the heating operation and the refrigerant flows in the direction of the solid line arrow.

The showcase side indoor unit 9 is initially set to the damper 3
3 opens the intake hose 29a and closes the intake hose 29b, and the damper 34 opens the exhaust hose 30a.
0b is closed (S1). Then, the compressor 21 is operated (S2), and the blower 27 is driven (S3).

As a result, in one of the terminal heat pumps 6, the refrigerant flows in the direction of the solid line arrow, and the refrigerant pressurized and heated by the compressor 14 passes through the heat exchanger 16 to raise the temperature of the brine in the brine pipe 5. . In the other terminal heat pump 7, the refrigerant pressurized and heated by the compressor 21 passes through the reheater 26, and the reheater 26 is heated. Then, the blower 27 sucks warm air in the upper part of the room from the intake / exhaust port 32 and reheats it by the reheater 26.
Warm air is delivered to the floor A from the intake / exhaust port 3 through the duct 2. The warm air mixes with the cool air on the floor A to warm the vicinity thereof, and the cold aisle on the floor A is relaxed.

On the other hand, the temperature of the refrigerant that has passed through the reheater 26 drops through the expansion valve 24, passes through the heat exchanger 23, and drops the temperature of the brine in the brine pipe 5. The heat exchange amount in the showcase side indoor unit 9 is generally smaller than the heat exchange amount in the ceiling side indoor unit, and the air supplied to the reheater 26 in this case is warm air above the ceiling. The temperature lowering effect on the brine is small, and the temperature of the brine tends to rise.

When the temperature of the brine rises and the temperature T _S detected by the temperature sensor 11 exceeds a predetermined upper limit temperature T _H (S4), the damper 33 closes the intake hose 29a, opens the intake hose 29b, and the damper 34 exhausts air. The hose 30a is closed and the exhaust hose 30b is opened (S5). Then, returning to the operation of step S4, the state is maintained until the detected temperature T _S becomes equal to or lower than the predetermined lower limit temperature T _L (S6).

As a result, the blower 27 sucks the cool air on the floor A from the intake / exhaust port 3, reheats it by the reheater 26, and sends it to the upper part of the room from the intake / exhaust port 32. Therefore, the cold aisle on the floor A is alleviated. The temperature of the refrigerant of the terminal heat pump 7 becomes lower than the temperature when the warm air is sucked, because the cool air sucked from the intake / exhaust port 3 passes through the reheater 26. That is, since the intake air temperature of the showcase side indoor unit 9 is lowered, the condensing force of the refrigerant in the reheater 26 is lower than that when the warm air is sucked in earlier, and the ratio of the discharge pressure to the suction pressure of the compressor 21. Since the (compression ratio) is reduced, the work of the compressor 21 is increased, the circulation amount of the refrigerant is increased, the heat radiation amount in the reheater 26 is increased, and the heat absorption amount in the heat exchanger 23 is increased. Also becomes larger, and the temperature drop of the brine by the heat exchanger 23 becomes larger.

When the detected temperature T _S becomes equal to or lower than the lower limit temperature T _L in step S6, the damper 33 opens the intake hose 29a and closes the intake hose 29b, and the damper 34 opens the exhaust hose 30a and closes the exhaust hose 30b (S7). ). Then, returning to the operation of step S4, the detected temperature T _S is equal to the upper limit temperature T _H.
The state is maintained until the above.

Although the flow chart does not describe the use of the four-way valve 22, the four-way valve 22 is switched to the cooling operation as needed when the temperature in the upper part of the store is extremely high during the heating operation in the store, and the refrigerant is cooled. Is circulated in the direction of the chain line arrow to operate the reheater 26 for cooling. Then, the cool air is sucked from the intake / exhaust port 3 and sent to the intake / exhaust port 32. At this time, it is recooled by the reheater 26. During this heating operation, the temperature of the heat source brine tends to drop,
By re-cooling the cool air, the temperature of the brine in the heat exchanger 23 is raised.

(Effects of the Invention) As described above, according to the present invention, when the temperature of the brine exceeds a predetermined upper limit temperature, cold air is sucked from the lower part of the showcase, heated and delivered to the upper part of the room, and the brine temperature is increased. When the temperature falls below the specified lower limit, warm air is drawn in from the upper part of the room, heated and sent to the lower part of the showcase, and the heat source for these heating is obtained from the brine, so the load on the ceiling side indoor unit increases. Insufficient center heat pump capacity can be covered by the indoor unit on the showcase side, and the cold aisle can be effectively mitigated without an increase in power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram of an air conditioning system showing an embodiment of the present invention,
FIG. 2 is a circuit diagram of the air conditioning system, FIG. 3 is a cross-sectional view of the main part of the showcase side indoor unit, and FIG. 4 is a flowchart showing the operation of the air conditioning system. 1 ... Showcase, 2 ... Duct, 3, 32 ... Intake / exhaust port, 4 ... Center heat pump, 5 ... Brine pipe,
6 ... One terminal heat pump, 7 ... Other terminal heat pump, 8 ... Ceiling side indoor unit, 9 ... Showcase side indoor unit, 10 ... Control unit, 11 ... Temperature sensor, 12 ...
... Circulation pump, 13 ... Ceiling, 16,23 ... Heat exchanger, 18, 28 ... Refrigerant pipe, 21 ... Compressor, 24 ...
Expansion valve, 26 ... Reheater, 27 ... Blower, 29a, 2
9b ... intake hose, 30a, 30b ... exhaust hose,
33,34 ... Damper.

Claims (1)

[Scope of utility model registration request] 1. A center heat pump for forming a brine of a constant temperature, a plurality of terminal heat pumps connected to the center heat pump through brine pipes, and one of the terminal heat pumps for one side through refrigerant pipes, and conditioned air in the room. Is connected to each of the other indoor heat pumps on the ceiling side and each of the other terminal heat pumps via a refrigerant pipe. The air taken in from the upper part of the room is heated and blown to the lower part of the showcase to mitigate cold aisles on the floor. In a control device of an air conditioning system having a showcase side indoor unit, a temperature sensor for detecting the temperature of the brine and an upper limit temperature and a lower limit temperature of the brine are set, and the temperature detected by the temperature sensor is the upper limit temperature. When it becomes the above, the air blow direction by the indoor unit on the showcase side is switched so that it is directed from the lower part of the showcase to the upper part of the room. The air blowing direction when a lower limit temperature or less and a control means for switching to direct the bottom of the showcase from said chamber upper control device of the air conditioning system, characterized in that.