JP3594426B2 - Air conditioner - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner, and in particular, circulates a phase-changeable fluid by a liquid pump between an outdoor unit and a plurality of indoor units, all or a majority of which are installed below the outdoor unit. The present invention relates to a device configured to be able to heat each indoor unit.
[0002]
[Prior art]
As this type of device, for example, an air conditioner having the configuration shown in FIG. 2 is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-151359. In the figure, 1 is an outdoor heat exchanger capable of supplying cold or hot water (hereinafter referred to as an outdoor unit), 4 is an indoor unit installed on a floor lower than the outdoor unit 1, 5 is a heat exchanger of the indoor unit, and 8 is flow rate adjustment Valves, 11 are electric pumps, 22 to 25 are on-off valves, which are connected by piping with the liquid phase pipe 6 and the gas phase pipe 7 as shown in the figure to form a closed circuit 3 and sealed in the closed circuit 3. The refrigerant circulates between the outdoor unit 1 and the indoor unit 4 so that the indoor unit 4 can perform cooling / heating. Reference numeral 26 denotes a liquid level sensor installed on the side surface of the outdoor unit 1, and controls the electric pump 11 so that the refrigerant liquid accumulated in the outdoor unit 1 during heating operation is constant.
[0003]
That is, in the air conditioner having the above configuration, when the temperature of the indoor air in which the indoor unit 4 is installed is high, the on-off valves 22 and 23 are closed and the on-off valves 24 and 25 are closed while the electric pump 11 is stopped. When opened, the flow control valve 8 is also opened, and the refrigerant sealed in the closed circuit 3 is cooled and condensed by the cold generated in the outdoor unit 1, and the refrigerant liquid condensed in the outdoor unit 1 flows down the liquid phase pipe 6 by its own weight. Then, it flows into the heat exchanger 5 via the opening / closing valves 24 and 25 and the flow regulating valve 8.
[0004]
The refrigerant liquid that has flowed into the heat exchanger 5 removes heat from the indoor air through the pipe wall of the heat exchanger to perform a cooling action, and the refrigerant itself evaporates and flows into the gas-phase pipe 7, where Circulates back to the outdoor unit 1, which is condensed and has a low pressure, so that there is no need for power to drive the electric pump 11 in summer when power consumption is maximum throughout the year, and running costs are reduced. There is an advantage that can be done.
[0005]
In addition, the on-off valves 22 and 25 are closed and the on-off valves 23 and 24 are opened, and the flow control valve 8 is also opened to start the electric pump 11 to cool the refrigerant sealed in the closed circuit 3 by the cold generated in the outdoor unit 1. When cooled and condensed, the refrigerant liquid condensed in the outdoor unit 1 flows down the liquid phase tube 6 by its own weight and the discharge force of the electric pump 11, enters the heat exchanger 5 through the flow control valve 8, and performs a cooling operation. Is forcedly circulated.
[0006]
As described above, when the electric pump 11 is activated to perform cooling, there is an advantage that a sufficient amount of the refrigerant liquid can be supplied to the heat exchanger 5 installed on the upper floor immediately below the outdoor unit 1. .
[0007]
On the other hand, when the temperature of the indoor air in which the indoor unit 4 is installed is low, the on-off valves 23 and 24 are closed and the on-off valves 22 and 25 are opened, and the flow control valve 8 is also opened to start the electric pump 11. Then, when the refrigerant enclosed in the closed circuit 3 is heated and evaporated by the heat generated in the outdoor unit 1, the refrigerant vapor evaporated in the outdoor unit 1 flows into the heat exchanger 5 through the gas phase pipe 7.
[0008]
The refrigerant vapor that has flowed into the heat exchanger 5 radiates heat to room air through the pipe wall of the heat exchanger to perform a heating action, and the refrigerant itself condenses and flows into the liquid phase pipe 6, and the on-off valve Circulation, such as reflux to the outdoor unit 1 by the electric pump 11 via 25 and 22, occurs, and the heating operation in the indoor unit 4 is continued.
[0009]
[Problems to be solved by the invention]
However, in the air conditioner having the above configuration, the refrigerant vapor generated by heating in the outdoor unit is supplied to the heat exchanger of the indoor unit by its vapor pressure. Supply cannot be made in time, the refrigerant condensed in the heat exchanger of the indoor unit stays. Since the pressure is constant, it is conceivable that the electric pump is stopped or the refrigerant liquid from the indoor unit does not return to the outdoor unit, which causes a problem that the pressure in the closed circuit locally increases more than necessary. The solution of these problems has been an issue.
[0010]
[Means for Solving the Problems]
The present invention, in order to solve the above-described problems of the prior art, an outdoor unit and a plurality of indoor units, all or a majority of which are installed below the outdoor unit, are connected by a gas phase pipe and a liquid phase pipe, Liquid condensed by radiating heat from the unit is transported from the indoor unit to the outdoor unit by the pump provided in the liquid phase pipe, and the gas absorbed by the outdoor unit and evaporated is flown into the indoor unit, and each indoor unit can be heated. In the device, the opening degree of the valve installed for each indoor unit and adjusting the amount of the fluid to be supplied to the indoor unit is maintained at a predetermined large opening degree over a predetermined time at the time of heating activation , and in particular, An object of the present invention is to provide an air conditioner having a configuration in which a valve of an indoor unit installed on a lower floor is maintained at a large opening degree for a predetermined time when heating is started .
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG. In these figures, the same reference numerals are given to the portions having the same functions as those described in FIG. 2 in order to facilitate understanding.
[0013]
In the figure, reference numeral 1 denotes an outdoor unit that can generate cold or warm heat when desired, such as an absorption refrigerator, and is installed in, for example, a machine room on a rooftop of a building, and is installed, for example, inside an evaporator. Through the heat exchanger 2, heat is exchanged with R-134a, which is a phase-changeable fluid sealed in the closed circuit 3, for example, R-134a, which can easily evaporate when the pressure is lowered even at a low temperature, causing a phase change. Let it.
[0014]
The heat exchanger 2 of the outdoor unit 1 and the heat exchanger 5 of the indoor unit 4 installed in each room of the building are connected and connected by a liquid phase pipe 6, a gas phase pipe 7, and a flow control valve 8 as shown in the figure. Thus, a closed circuit 3 is formed.
[0015]
9 is a cooling / heating switching valve (open / close valve) provided in the common part 6A of the liquid phase pipe 6, 6B is a bypass pipe connected to the liquid phase pipe common part 6A so as to bypass the cooling / heating switching valve 9, and 10 and 11 are this bypass pipe. It is a receiver tank provided in the pipe 6B and an electric pump for heating.
[0016]
In addition, 12 is a blower for blowing indoor air to the heat exchanger 5 to recirculate the indoor air, and 13 and 14 are provided at the entrance and exit of R-134a of the heat exchanger 5 to detect the temperature of R-134a. The temperature difference between the inlet-side temperature sensor 13 and the outlet-side temperature sensor 14 increases as the air-conditioning load increases, and the temperature difference decreases as the air-conditioning load decreases.
[0017]
The outdoor unit 1 is provided with an outdoor control device 15, and the indoor unit 4 is provided with an indoor control device 16. The indoor control device 16 can convert the valve opening of the flow control valve 8 and the temperature information detected by the temperature sensors 13 and 14 into a communication signal, and convert the communication signal received from the outside into a required control signal. A signal converter (not shown) capable of conversion is built in, the outdoor control device 15 and the indoor control device 16 are connected by a communication line 17, and a control signal output from the outdoor control device 15 is transmitted to the indoor control device 16. And the opening degree of the flow control valve 8 is controlled. In addition, a remote controller 18 that can communicate with the indoor control device 16 and can start / stop cooling / heating, select the intensity of ventilation, set a temperature, and the like is provided for each indoor unit 4.
[0018]
In the air conditioner having the above configuration, when the outdoor unit 1 generates heat and closes the cooling / heating switching valve 9 and operates the electric pump 11, the heat generated in the outdoor unit 1 heats the R-134 a of the closed circuit 3. Since the R-134a is heated through the tube wall of the exchanger 2, the R-134a evaporates and enters the gas phase pipe 7, and is supplied to the heat exchanger 5 of each indoor unit 4.
[0019]
In each of the heat exchangers 5, since the low-temperature indoor air is forcibly supplied by the blower 12, the R-134a releases heat to the indoor air and condenses, thereby performing a heating action.
[0020]
The condensed and liquefied R-134a enters the lower receiver tank 10 through the flow control valve 8, and is circulated by the electric pump 11 to be returned to the heat exchanger 2 of the outdoor unit 1.
[0021]
However, as described in the section of the subject of the invention, when a sudden heat load occurs at the time of starting heating, the supply of the R-134a evaporated in the outdoor unit 1 to the heat exchanger 5 of the indoor unit 4 cannot be made in time, and In the exchanger 5, the condensed R-134a stays, that is, a so-called refrigerant stagnation phenomenon occurs, cool air is blown into the room, and the amount of R-134a sealed in the closed circuit 3 is constant. It is conceivable that the electric pump 11 is stopped or the R-134a from the indoor unit 4 does not return to the outdoor unit 1, which causes a problem that the pressure in the closed circuit 3 locally increases more than necessary.
[0022]
Therefore, when the heating operation is started, the opening degree of the flow control valve 8 is set to a high level for a predetermined time, for example, 30 seconds by a control signal output from the outdoor control device 15 to each indoor control device 16 via the communication line 17, For example, a setting is made such that the opening is fixed at 75% with respect to the full opening.
[0023]
For this reason, even if the air-conditioning load suddenly increases at the time of starting the heating operation and the amount of heat released from the R-134a in the heat exchanger 5 suddenly increases, the amount of R-134a supplied from the outdoor unit 1 is large. The inconvenience that R-134a condenses on the inlet side of the vessel 5 and cool air blows out into the room is avoided.
[0024]
The liquid of R-134a condensed in the heat exchanger 5 is less likely to be discharged to the receiver tank 10 side because the heat exchanger 5 installed on the lower floor has a smaller vertical difference from the receiver tank 10. Further, as the heat exchanger 5 installed on the lower floor, the R-134a evaporated in the heat exchanger 2 of the outdoor unit 1 operates in a state where the pressure is reduced, the heat exchanger 5 installed on the lower floor is lower. The more condensed R-134a liquid is difficult to discharge. For this reason, as the heat exchanger 5 is installed on the lower floor, the opening of the flow control valve 8 is greatly increased, and the heating operation is started.
[0025]
Further, the amount of R-134a discharged from the heat exchanger 5 through the flow control valve 8 is larger for the indoor unit 4 installed on the upper floor, even if the opening degree is the same as described above, Since the number of indoor units 4 installed on the floor tends to be smaller, the same control signal is output to the flow rate regulating valve 8 to open it, because the temperature information detected by the temperature sensors 13 and 14 is the same. If the degree control is performed, it becomes difficult to supply an appropriate amount of R-134a according to the heating load.
[0026]
Therefore, even in the normal operation except the start-up operation, even if the temperature information detected by the temperature sensors 13 and 14 is the same, the outdoor control device 15 outputs different control signals depending on the floor where the indoor unit 4 is installed. In other words, in the case of an air conditioner in which the indoor unit 4 installed on the 10th floor is divided into ten floors, for example, a predetermined control program for opening the flow control valve 8 more widely as the indoor unit 4 is installed on the lower floor. The correction coefficient of the indoor unit 4 installed on the highest floor is set to 1, and a value obtained by adding 0.05 to 1 every time the floor goes down is set as a correction coefficient for that floor, and the temperature information detected by the temperature sensors 13 and 14 is used as the correction coefficient. First, the opening of the flow control valve 8 at the time of no correction is obtained, and the opening is further multiplied by a required correction coefficient to obtain the opening of the flow control valve 8 that is actually output to the indoor unit 4. Flow of the indoor unit 4 A control program for outputting a control signal for adjusting the opening degree of the adjustment valve 8 is stored in the outdoor control device 15, and the opening degree of each flow adjustment valve 8 of each indoor unit 4 is controlled based on the control program. To be configured.
[0027]
Therefore, when the outdoor control device 15 receives the temperature information detected by the temperature sensors 13 and 14 from the indoor control device 16 via the communication line 17, the outdoor control device 15 transmits the signal transmitted from the indoor unit 4 on which floor Is first determined to determine the correction coefficient, the opening degree of the flow control valve 8 is calculated by a predetermined program in consideration of the correction coefficient thus determined, and a required control signal is transmitted to the communication line 17. The flow is output to the corresponding indoor control device 16 via the controller, and the opening of the flow control valve 8 is adjusted to the opening corresponding to the installation floor.
[0028]
Further, in the air conditioner of the present invention having the above-described configuration, when the indoor temperature is high, the cooling / heating switching valve 9 is opened without operating the electric pump 11 and the outdoor unit 1 generates cold heat. Since the R-134a of the closed circuit 3 is cooled through the pipe wall of the heat exchanger 2 by the generated cold, the R-134a condenses and accumulates in the liquid phase pipe 6 on the downstream side, and the flow control valve of the indoor unit 4 8 to each heat exchanger 5.
[0029]
In each of the heat exchangers 5, since the high temperature indoor air is forcibly supplied by the blower 12, the R-134a removes heat from the indoor air and evaporates to perform a cooling operation.
[0030]
Then, the R-134a is cooled, condensed and liquefied, and naturally circulates by returning to the heat exchanger 2 of the outdoor unit 1 at a low pressure through the gas recirculation pipe 7.
[0031]
In addition, as shown by a broken line in FIG. 1, a configuration in which the receiver tank 19 and the electric pump 20 are provided may be employed.
[0032]
With such a configuration, the transport force of the electric pump 20 is added to the difference in specific gravity between the liquid and the gas of R-134a, so that a part of the indoor unit 4 is on the same floor as the outdoor unit 1 or higher than the outdoor unit 1. Even if installed at the position, the circulation for the cooling operation of R-134a is reliably performed. In this case, it is preferable to connect a bypass pipe 6C provided with a cooling / heating switching valve (open / close valve) 21 that opens during the heating operation and closes during the cooling operation to the liquid phase pipe common part 6A as shown by a broken line.
[0033]
In addition, as an absorption refrigerating machine that can supply cold heat or hot heat from the heat exchanger 2 piped to the evaporator, for example, the one disclosed in JP-A-7-318189 can be used.
[0034]
Further, the temperature sensors 13 and 14 are installed so as to be able to detect a change in the temperature of the indoor air blown to the heat exchanger 5, and instead of the temperature sensors 13 and 14, R-134a at the entrance and exit of the heat exchanger 5 is used. It is also possible to provide a pressure sensor capable of detecting a pressure difference and output the air conditioning load to the outdoor control device 15.
[0035]
The phase-changeable fluid sealed in the closed circuit 3 may be a fluid capable of transferring heat by latent heat, such as R-407c, R-404A, and R-410c, in addition to R-134a. .
[0036]
【The invention's effect】
As described above, the air conditioner of the present invention is installed in each indoor unit and adjusts the opening degree of the flow control valve that adjusts the amount of the phase changeable fluid supplied to the indoor unit when the heating operation is started. Since the opening degree is maintained at a predetermined large value over a predetermined time, the supply amount of the fluid does not run short even if the heating load suddenly increases at the time of startup.
[0037]
For this reason, the disadvantage that the fluid is condensed at the heat exchanger inlet side of the indoor unit and the cool air blows into the room does not occur as in the related art.
[0038]
Further, as shown in the embodiment, in an air conditioner using an absorption type chiller / heater that can generate cold or warm heat by burning gas or oil as an outdoor unit, the electric power during cooling has a control relationship. Since it is not used except for the consumed power, it is effective in cutting the peak of power during the high summer months when the amount of power generation is maximized throughout the year.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an embodiment configured to allow cooling / heating.
FIG. 2 is an explanatory diagram of a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outdoor unit 2 Heat exchanger 3 Closed circuit 4 Indoor unit 5 Heat exchanger 6 Liquid phase pipe 6A Liquid phase pipe common part 6B / 6C Bypass pipe 7 Gas phase pipe 8 Flow control valve 9 Cooling / heating switching valve 10 Receiver tank 11 Electric pump 12 Blowers 13 and 14 Temperature sensor 15 Outdoor control device 16 Indoor control device 17 Communication line 18 Remote control 19 Receiver tank 20 Electric pump 21 Cooling / heating switching valve

Claims (1)

A gas phase pipe and a liquid phase pipe are connected between the outdoor unit and a plurality of indoor units, all or a majority of which are installed below the outdoor unit, and the liquid condensed by radiating heat in the indoor unit is removed from the outdoor unit. It is a device configured to be conveyed by a pump provided in a liquid phase pipe to the machine, to absorb the gas absorbed by the outdoor unit and evaporate and flow into the indoor unit, and to be capable of heating in each indoor unit, and installed for each indoor unit. The opening degree of the valve for adjusting the amount of the gas supplied to the indoor unit is maintained at a predetermined large opening degree for a predetermined time at the time of heating activation , and in particular, as the valve of the indoor unit installed on the lower floor, An air conditioner characterized by maintaining a large opening degree for a predetermined time when heating is started .

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