JP5125695B2 - Air conditioning system - Google Patents

Description

  The present invention belongs to the technical field of an air-conditioning system that performs an air-conditioning operation including indoor air conditioning.

  2. Description of the Related Art Conventionally, an air conditioning system that performs an air conditioning operation such as cooling and heating indoor air includes a compressor that compresses a refrigerant, an indoor heat exchanger mounted on a so-called indoor unit, and an outdoor mounted on a so-called outdoor unit. The outdoor heat exchanger and the indoor exchanger function as a condenser that condenses the refrigerant compressed by the compressor or an evaporator that evaporates the condensed refrigerant. Thus, cooling operation or heating operation is performed.

  Incidentally, in recent years, in this type of air conditioning system, a technique for controlling the operation of the compressor by using an inverter circuit is becoming common, and the following method is widely adopted as the control method.

  That is, when the air conditioning load is large, for example, when the temperature difference between the room temperature and the target temperature is larger than a predetermined range, the compressor is driven at a relatively large constant frequency. Further, when the temperature difference falls within the predetermined range, that is, when the air conditioning load becomes small, the operation operation and the pause operation are repeated as shown in FIG. Specifically, when the temperature difference falls within the predetermined range, the drive signal is stopped without being output to the compressor, and when the temperature difference between the room temperature and the target temperature exceeds the predetermined range due to the stop, the frequency is again returned. Then, the operation is performed by driving the compressor, and when the temperature difference is within the predetermined range again by the operation, the operation of pausing again is repeatedly performed. In addition, the frequency during the driving operation period is not fixed to one frequency, but the frequency may be lowered step by step as shown by a broken line in FIG.

  On the other hand, in Patent Document 1 below, “the operation of low-priority electric devices is turned off in order until the total power consumption falls below the set upper limit, thereby stopping the operation of the electric devices in the entire wiring system. “Prevent (first page right column, line 14 to second page left column, second line)”.

Further, Patent Document 2 below discloses that “starting / stopping of the air conditioner or capacity control is performed every predetermined time according to the control priority so that the total power consumption of the air conditioner is equal to or less than the total target power ([0005]). ”,“ A sum of the rated power consumption for each of the plurality of air conditioners 2 input by the power input means 4 and the power consumption according to the operation time of each of the compressor and the blower is calculated by the power consumption calculation means 7. In accordance with the control priority determined in order of the suction temperature by the priority determination unit 6 so that it becomes equal to or lower than the target power input by the power input unit 5, the plurality of air conditioners 2 are set at predetermined intervals by the power adjustment unit 8. "Sequential start / stop or ability control ([0015])".
Japanese Patent No. 2988998 JP 2006-78045 A

  It is assumed when installing an air conditioning system in a facility where the air conditioning load may temporarily increase, such as when the space to be air conditioned is relatively large or the temperature difference between the room temperature and the target temperature is relatively large. In general, an air conditioning system having a large air conditioning capacity is selected in consideration of the maximum air conditioning load to be obtained.

  Here, in the above-described control that repeats the operation and the stop, a large amount of power is required when switching from the stop state to the operation state, and particularly in the air conditioning system having the large air conditioning capability as described above, If the control that repeats the above is adopted, the power consumption during switching from the stop to the operation is extremely large, which is not preferable from the viewpoint of energy efficiency. In addition, the technique which considered this point is not disclosed by the said patent document 1,2.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a technique for improving energy efficiency in an air conditioning system.

The invention according to claim 1 is a compressor that compresses the refrigerant, a first motor that drives the compressor, a condenser that condenses the refrigerant compressed by the compressor, and a condenser that is condensed by the condenser. An evaporator that evaporates the refrigerant, a blower that sends air generated by the operation of the condenser and the evaporator, a second motor that drives the blower, the first motor, An inverter circuit unit that outputs AC power to at least one of the two motors, and a predetermined first frequency when the air-conditioning load of the air-conditioning target space is outside a predetermined range with reference to a predetermined load. A first driving mode for outputting AC power from the inverter circuit unit; and AC power having a constant second frequency smaller than the first frequency when the air conditioning load is within the certain range. Repeatedly detecting a drive control unit and a second driving mode in which output from the circuit unit, the sum of the current supplied to the predetermined units of the air conditioning system including the first or the second motor from the commercial power source And a limit value storage unit that stores a plurality of types of limit values for the sum of currents supplied from the commercial power supply to the units in the first drive mode, and the drive control unit includes: In the first drive mode, a limit value corresponding to the state of the air conditioning system is selected from a plurality of limit values stored in the limit value storage unit, and the current detected by the current detection unit is selected. The frequency of the AC power is changed so as not to exceed the limit value, and the state is an activated state until a predetermined time elapses after the main power supply of the air conditioning system is turned on. Is selected from among a plurality of limit values stored in the limit value storage unit, a limit value larger than the limit value set in the second drive mode, and the current detected by the current detection unit is The air conditioning system changes the frequency of the AC power so as not to exceed the selected limit value .

  According to the present invention, since the AC power output from the inverter circuit unit in the second drive mode is AC power having a constant second frequency, operation and pause in the second drive mode are performed. As in the prior art that repeats the above, switching from the hibernation state to the operation state, which requires large electric power, is not performed.

  In the present invention, the AC power having the predetermined frequency is also output during the pause period in the prior art in which the operation and the pause are repeated, but even if this amount of power is subtracted, the pause that requires a large amount of power as in the prior art. By not switching from the operation to the operation, the energy efficiency can be improved as compared with the conventional technique.

  The air conditioning load refers to the amount of heat required in the air conditioning system to set the air in the air conditioning target space to the target temperature.

The invention described in claim 2 is a compressor that compresses refrigerant, a first motor that drives the compressor, a condenser that condenses the refrigerant compressed by the compressor, and a condenser that is condensed by the condenser. An evaporator that evaporates the refrigerant, a blower that sends air generated by the operation of the condenser and the evaporator, a second motor that drives the blower, the first motor, An inverter circuit unit that outputs AC power to at least one of the two motors, and a predetermined frequency for obtaining a driving force of the first or second motor with respect to a predetermined load for the air-conditioning load of the air-conditioning target space A first driving mode for outputting AC power having the inverter circuit unit from the inverter circuit unit; and AC power having a frequency for obtaining a driving force smaller than the driving force is output from the inverter circuit unit. A drive control unit having two drive modes, a current detection unit that repeatedly detects a sum of currents supplied from a commercial power source to each predetermined unit of the air conditioning system including the motor, and the first drive mode. A limit value storage unit that stores a plurality of types of limit values for the sum of currents supplied to the respective units from the commercial power supply, and the drive control unit includes the limit value storage unit in the first drive mode. The limit value corresponding to the state of the air conditioning system is selected from the plurality of limit values stored in the control unit, and the current detected by the current detection unit does not exceed the selected limit value. When the frequency is changed and the state is an activated state from when the main power supply of the air conditioning system is turned on until a predetermined time elapses, the state is stored in the limit value storage unit A limit value larger than the limit value set in the second drive mode is selected from the limit values of the number, and the AC is detected so that the current detected by the current detection unit does not exceed the selected limit value. It is an air conditioning system that changes the frequency of electric power .

The magnitude of the current limit value determines the magnitude of the air conditioning capability of the air conditioning system. Thus, according to the invention described in claim 1, a plurality of limit values for the current, in the first driving mode, the current detection is detected by the unit current, the limit value storage unit Since the frequency of the AC power is changed so as not to exceed the limit value selected from the plurality of stored limit values, a plurality of air conditioning capabilities can be provided in the first drive mode.

According to a third aspect of the present invention, in the air conditioning system according to the first or second aspect, the input for selectively selecting the current limit value from a plurality of limit values stored in the limit value storage unit. A current limit value input selection unit for performing the control, wherein the drive control unit is configured to limit the current detected by the current detection unit selected by the current limit value input selection unit in the first drive mode. The frequency of the AC power is changed so as not to exceed the value.

  According to the present invention, the current limit value input selection unit can alternatively select the current limit value from a plurality of limit values stored in the limit value storage unit. As a result, the user can select the air conditioning capability of the air conditioning system in the first drive mode by the current limit value input selection unit.

According to a fourth aspect of the present invention, in the air conditioning system according to the first aspect , an environment detection unit that detects an environment is provided, and the drive control unit stores the limit value storage unit in the first drive mode. The limit value is selected based on the environment detected by the environment detection unit from the plurality of limit values, and the AC is detected so that the current detected by the current detection unit does not exceed the selected limit value. The frequency of electric power is changed.

  According to this invention, the limit value corresponding to the environment is automatically selected from the plurality of limit values stored in the limit value storage unit. As a result, the air conditioning system can be automatically operated with an air conditioning capacity suitable for the environment.

According to a fifth aspect of the present invention, in the air conditioning system according to the fourth aspect , the environment detection unit detects a temperature of outside air, and the drive control unit is configured to perform the operation in the first drive mode. A limit value is selected from a plurality of limit values stored in the limit value storage unit based on the temperature detected by the environment detection unit, and the current detected by the current detection unit exceeds the selected limit value The frequency of the AC power is changed so as not to be present.

  According to this invention, the limit value according to the outside air temperature is automatically selected from the plurality of limit values stored in the limit value storage unit.

According to a sixth aspect of the present invention, in the air conditioning system of the fourth aspect , the environment detection unit detects a temperature of indoor air, and the drive control unit is in the first drive mode. The limit value is selected from a plurality of limit values stored in the limit value storage unit based on the difference between the indoor air temperature detected by the environment detection unit and the target temperature, and the current detection unit The frequency of the AC power is changed so that the detected current does not exceed the selected limit value.

  According to this invention, the limit value corresponding to the difference between the temperature of the room air and the target temperature is automatically selected from the plurality of limit values stored in the limit value storage unit.

A seventh aspect of the present invention is the air conditioning system according to any one of the first to sixth aspects, wherein the first drive mode is the predetermined frequency when the air conditioning load is larger than the certain range. In this drive mode, AC power having a higher frequency is output, and the limit value storage unit stores a limit value that is larger than the limit value set in the second drive mode.

  According to this invention, a plurality of air conditioning capabilities larger than those in the second drive mode are provided as the air conditioning capabilities in the first drive mode, and the air conditioning capabilities are set manually or automatically from these air conditioning capabilities. A configuration can be realized.

In addition, according to the above invention, the limit value according to the state of an air conditioning system is automatically selected from the some limit value memorize | stored in the said limit value memory | storage part. As a result, the air conditioning system can be automatically operated with an air conditioning capacity suitable for the current state of the air conditioning system.

Automatic addition, according to the above invention, when the starting state, from among a plurality of limit value stored in the limit value storing unit, larger limit value than the limit value set in the second drive mode is Selected. Accordingly, it is possible to realize a configuration in which the air conditioning capability is automatically increased from that of the second drive mode when the air conditioning capability of the air conditioning system is to be increased from that of the second drive mode.

The invention according to claim 8 is the air conditioning system according to claim 1 or 2 , wherein the state is a state in which the air conditioning system is performing a defrost operation, and the drive control unit is configured to perform the defrost operation. In the state, a limit value larger than the limit value set in the second drive mode is selected from a plurality of limit values stored in the limit value storage unit, and the current detected by the current detection unit The frequency of the AC power is changed so as not to exceed the selected limit value.

  According to the present invention, when the defrost operation is performed, a limit value larger than the limit value set in the second drive mode is automatically selected from the plurality of limit values stored in the limit value storage unit. Selected. Accordingly, it is possible to realize a configuration in which the air conditioning capability is automatically increased from the second drive mode when the air conditioning system is in the defrost operation implementation state in which the air conditioning capability should be greater than that in the second drive mode.

Invention of Claim 9 is equipped with the heating degree detection part which detects the heating degree of the discharge pipe through which the refrigerant | coolant discharged from the said compressor passes in the air conditioning system of Claim 1 or 2 , The said state is When the degree of heating detected by the degree of heating detection unit is smaller than a predetermined value, and the drive control unit is in a state where the degree of heating is smaller than a predetermined value, the limit value storage unit A limit value larger than the limit value set in the second drive mode is selected from the stored limit values so that the current detected by the current detector does not exceed the selected limit value. The frequency of the AC power is changed.

  According to this invention, when the degree of heating is smaller than a predetermined value, the limit value set in the second drive mode is selected from the plurality of limit values stored in the limit value storage unit. A larger limit value is automatically selected. Thereby, when the degree of heating at which the air conditioning capacity of the air conditioning system should be greater than that in the second drive mode is smaller than a predetermined value, the air conditioning capacity is automatically increased from that in the second drive mode. Can be realized.

A tenth aspect of the present invention is the air conditioning system according to any one of the first to ninth aspects, wherein the inverter circuit unit outputs AC power to the first motor that drives the compressor. .

  According to this invention, a plurality of air conditioning capacities in the first drive mode can be set by controlling the operation of the first motor that drives the compressor.

The invention according to claim 11 is the air conditioning system according to any one of claims 1 to 10 , wherein the inverter circuit unit outputs AC power to the second motor that drives the blower unit. .

  According to this invention, a plurality of air conditioning capacities in the first drive mode can be set by controlling the operation of the second motor that drives the blower.

  According to the present invention, since the AC power output from the inverter circuit unit in the second drive mode is an AC power having a constant second frequency, it is compared with the conventional technique in which operation and pause are repeated. Energy efficiency.

  Hereinafter, an embodiment of an air-conditioning system according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a first embodiment of an air conditioning system.

  As shown in FIG. 1, the air conditioning system 1 includes an indoor unit 2 that is attached to an indoor ceiling surface or wall surface, and an outdoor unit 3 that is installed at a suitable location outside the room. The outdoor unit 3 is connected by a piping unit 4. The indoor unit 2, the outdoor unit 3, and the piping unit 4 constitute an annular refrigerant circuit, and the indoor air is cooled or heated by circulating the refrigerant in the refrigerant circuit.

  The indoor unit 2 includes a heat transfer tube that is bent back multiple times and a plurality of fins through which the heat transfer tube is inserted, and an indoor heat exchanger 5 that exchanges heat with the air in contact with the indoor unit 2, An indoor fan 6 (an example of the air blowing unit) that introduces (inhales) the air into the indoor unit 2 and releases the air after performing heat exchange with the indoor heat exchanger 5; And an indoor fan motor 7 for rotating the indoor fan 6.

  The outdoor unit 3 includes a compressor 8 for compressing refrigerant, a switching valve 9 connected to the discharge side of the compressor 8, an accumulator 10 connected to the suction side of the compressor 8, and the switching valve 9. It has the outdoor heat exchanger 11 connected, the motor operated valve 12 connected to the outdoor heat exchanger 11, and the outdoor fan 13 for discharging | emitting the air after the heat exchange by the outdoor heat exchanger 11 outside.

The electric valve 12 is connected to a pipe 17 having a filter 14 and a liquid closing valve 15, and is connected to one end of the indoor heat exchanger 5 of the indoor unit 2 through the pipe 17. The switching valve 9 is connected to a pipe 18 having a gas closing valve 16 , and is connected to the other end of the indoor heat exchanger 5 of the indoor unit 2 through the pipe 18. The pipes 17 and 18 are pipes through which a refrigerant flows, and constitute the pipe part 4. The outdoor fan 13 is rotationally driven by an outdoor fan motor 19.

  In the air conditioning system 1 having such a configuration, during the cooling operation, the refrigerant discharged from the compressor 8 is supplied to the outdoor heat exchanger 11, and the refrigerant is condensed in the outdoor heat exchanger 11. The electric valve 12, the filter 14, the liquid closing valve 15 and the pipe 17 are supplied to the indoor heat exchanger 5, and the refrigerant is evaporated in the indoor heat exchanger 5. By this operation, cool air is generated in the indoor heat exchanger 5, and the cool air is discharged into the room by the indoor fan 6. In this cooling operation, the indoor heat exchanger 5 functions as the evaporator, and the outdoor heat exchanger 11 functions as the condenser.

  On the other hand, during the heating operation, the refrigerant discharged from the compressor 8 is supplied to the indoor heat exchanger 5 through the pipe 18, and after the refrigerant is condensed in the indoor heat exchanger 5, the motor-operated valves 12, The refrigerant is supplied to the outdoor heat exchanger 11 through the filter 14, the liquid closing valve 15 and the pipe 17, and the refrigerant is evaporated in the outdoor heat exchanger 11. By this operation, warm air is generated in the indoor heat exchanger 5, and the warm air is released into the room by the indoor fan 6. During the heating operation, the indoor heat exchanger 5 functions as the condenser, and the outdoor heat exchanger 11 functions as the evaporator.

  FIG. 2 is a block diagram showing the configuration of the air conditioning system 1. In addition, the same number is attached | subjected about the structure same as the structure shown in FIG. 1, and the description is abbreviate | omitted.

  As shown in FIG. 2, the air conditioning system 1 includes a compressor 8, a compressor drive unit 20, an indoor fan 6, an indoor fan drive unit 21, an outdoor fan 13, an outdoor fan drive unit 22, and an input operation. A unit 23 and a control unit 24 are provided.

  The compressor drive unit 20 includes a motor 25 (corresponding to the first motor) that drives the compressor 8, and a compressor motor drive circuit unit 26 that generates a drive signal for driving the compressor motor 25. In detail, the compressor motor drive circuit section 26 has a configuration as shown in FIG.

  As shown in FIG. 3, the compressor motor drive circuit unit 26 includes a converter circuit 27 and an inverter circuit 28 (components of the inverter circuit unit). The converter circuit 27 converts an AC voltage from an AC power source E1, which is a commercial power source of an electric power company, into a DC voltage, and includes a rectifier circuit 29, a boost chopper 30, a smoothing circuit 31, and resistors R1, R2, and R3. Yes.

  The rectifier circuit 29 is composed of, for example, a diode bridge, and full-wave rectifies the AC voltage output from the AC power supply E1. The step-up chopper 30 boosts the DC voltage output to the inverter circuit 28 to a predetermined level, and includes a coil L1, a diode D1, a switching element Q1, and a diode D2. The step-up chopper 30 receives the PWM signal output from the control unit 24, the switching element Q1 is turned on / off, and the switching element Q1 is turned off by the electromagnetic energy accumulated in the coil L1 while the switching element Q1 is turned on. Is discharged during this period, a predetermined level of DC voltage is output to the inverter circuit 28.

  As the switching element Q1, an npn-type bipolar transistor is employed, a collector is connected to a connection point between the coil L1 and the diode D1, a base is connected to the control unit 24, and an emitter is connected to the ground. The diode D1 has an anode connected to the coil L1 and a cathode connected to the resistor R1. The diode D2 has an anode connected to the emitter of the switching element Q1, and a cathode connected to the collector of the switching element Q1. The smoothing circuit 31 includes a capacitor C1, and smoothes the voltage output from the boost chopper 30.

  The resistor R1 has one end connected to the cathode of the diode D1 and the other end connected to the resistor R2. The resistor R2 has one end connected to the resistor R1 and the other end connected to the ground. The resistor R3 is connected between the smoothing circuit 31 and the inverter circuit 28 on the ground line so as to monitor the current for driving the compressor motor 25, and one end of the resistor R3 is connected to the control unit 24. It is connected.

  The inverter circuit 28 includes switching elements Q2 and Q3 and diodes D3 and D4. The inverter circuit 28 converts the DC voltage output from the converter circuit 27 under the control of the control unit 24 into an AC voltage having a predetermined level of amplitude and frequency. And the compressor motor 25 is driven.

  The switching element Q2 is composed of an npn-type bipolar transistor, the base is connected to the control unit 24, the emitter is connected to the collector of the switching element Q3, and the collector is connected to the capacitor C1. The switching element Q3 is composed of an npn-type bipolar transistor, and has a base connected to the control unit 24 and an emitter connected to the ground. The diode D3 has an anode connected to the emitter of the switching element Q2, and a cathode connected to the collector of the switching element Q2. The diode D4 has an anode connected to the emitter of the switching element Q3 and a cathode connected to the collector of the switching element Q3. The compressor motor 25 is composed of, for example, a brushless motor, and operates by the AC voltage output from the inverter circuit 28 to drive the compressor 8. A PWM signal is output from the control unit 24 to the switching elements Q1 to Q3 so that the rotational speed of the compressor motor 25 becomes a predetermined speed.

  In such a configuration, by increasing the drive frequency of the switching elements Q2 and Q3, the current supplied to the compressor motor 25 increases, and the refrigerant compression operation by the compressor 8 becomes strong.

  Returning to FIG. 2, the indoor fan drive unit 21 includes a motor 7 for driving the indoor fan 6 (corresponding to the second motor) and a motor drive circuit for indoor fans that generates a drive signal for driving the motor 7. And a portion 33. The outdoor fan drive unit 22 includes a motor 19 that drives the outdoor fan 13, and an outdoor fan motor drive circuit unit 35 that generates a drive signal for driving the motor 19. The configurations of the indoor fan motor drive circuit unit 33 and the outdoor fan motor drive circuit unit 35 are the same as those of the compressor motor drive circuit unit 26, and thus the description thereof is omitted.

  Although not described in detail, the input operation unit 23 includes various buttons and switches installed on a remote controller (not shown) that controls the operation of the air conditioning system 1. In particular, the input operation unit 23 of the present embodiment is provided with a rotary switch 36 (an example of the current limit value input selection unit) as will be described later.

  The control unit 24 has a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) that stores a program that defines the operation of the CPU, and a function and work area for temporarily storing data. A random access memory (RAM) or the like having the above functions is provided, and controls the entire air conditioning system 1.

  By the way, in the air-conditioning system 1 of this embodiment, when performing air-conditioning operation with a certain temperature as a target temperature, the operation of the compressor 8 is controlled according to the air-conditioning load at each time point, but the energy efficiency is improved. Therefore, the compressor 8 is further driven by the following control method.

  That is, for example, when the air conditioning load is large, such as when the indoor space is relatively large or when the temperature difference between the indoor air temperature and the target temperature is relatively large, the compressor motor of the compressor 8 with a relatively large driving frequency. When the air conditioning load is small (corresponding to the case where the air conditioning load is within a certain range based on a predetermined load), the driving of the air conditioning load 25 is substantially the same as the prior art. The compressor motor 25 is driven at a drive frequency smaller than the drive frequency of the above, and the drive frequency is a constant drive frequency, which is different from the conventional technique in which operation and pause are repeated. The driving mode when the air conditioning load is large is an example of the first driving mode, and the driving mode when the air conditioning load is small corresponds to the second driving mode.

  In addition, the air conditioning capacity of the air conditioning system 1 when the air conditioning load is large may vary depending on the user's required air conditioning capacity, such as wanting to cool the air in the room as soon as possible or not so quickly, It depends on the size of the room to be air-conditioned. Therefore, in this air conditioning system 1, considering this point, a plurality of capacity levels are set for the air conditioning capacity when the air conditioning load is large, and this air conditioning capacity level is manually set using a rotary switch 36 described later. It is different from the prior art in that it can be set by

  Furthermore, in this embodiment, the maximum capacity of the air conditioning system 1 when the upper limit value of the current supplied to the outdoor unit 3 (the sum of the currents supplied to each part in the outdoor unit 3) is large is the air conditioning system 1 Focusing on the fact that it is a parameter that determines the above, a plurality of capability levels are provided by setting a plurality of the upper limit values.

  In order to realize the above configuration, as shown in FIG. 2, the air conditioning system 1 includes a rotary switch 36, and the control unit 24 includes a table storage unit 37 (an example of the limit value storage unit). The current detection unit 38 and the drive control unit 39 are functionally provided.

  FIG. 4 is a diagram illustrating the appearance of the rotary switch 36. The rotary switch 36 is for manually setting the capacity level related to the air conditioning capacity when the air conditioning load is large. In the form shown in FIG. 4, the capacity level is “high”, which is the maximum, and the capacity level is the minimum. The three ability levels of “standard” and “medium”, which are intermediate ability levels, are switches configured as selection targets. Note that the number of ability levels is not limited to three.

  In this embodiment, the rotary switch 36 is separated from the remote controller, and includes a case 40 and a rotary dial 41 installed on one side of the case 40. The rotary dial 41 is configured to be rotatable in the direction of an arrow Q with the normal line O on the one side surface as a rotation center. Of the one side surface of the case 40, within a predetermined range in which the tip of the rotary dial 41 can be opposed, the names of the ability levels of “strong”, “medium”, and “standard” are written at substantially equal intervals. .

  Although not shown, the case 40 has a plurality of fixed contacts and a movable contact that is interlocked with the rotating operation of the rotary dial 41 at an appropriate position inside the case 40. The installation position of each fixed contact is associated with the name notation position of each ability level, while the movable contact is interlocked with the tip of the rotary dial 41, and the name notation position and the rotation dial of each ability level. When the tip of 41 faces, the movable contact and the fixed contact come into contact. When the movable contact and the fixed contact come into contact with each other, the rotary switch 36 outputs an output signal corresponding to the type of the fixed contact that has come into contact with the movable contact to the control unit 24 described later.

  As shown in FIG. 5, the table storage unit 37 is set by the rotary switch 36, and the capacity levels “strong”, “medium”, “standard” of the air conditioning system 1 when the air conditioning load is large, and the outdoor unit 3 The current upper limit value table showing the correspondence with the upper limit value (hereinafter referred to as the current upper limit value) for the current supplied to is stored.

In FIG. 5, the current upper limit value I ₃ is associated with the ability level “strong”, and the current upper limit value I ₂ (<I ₃ ) is associated with the ability level “medium”. “Standard” indicates a current upper limit value table associated with the current upper limit value I ₁ (<I ₂ ). Further, although a current limit value is set separately even when the air conditioning load is small, each of the current upper limit values I _{1 to} I ₃ is a current limit when the indoor air temperature is substantially equal to the target temperature. The value is preferably 1.2 times or more.

  The current detection unit 38 repeatedly detects the current supplied to the outdoor unit 3 (in this embodiment, at a constant period).

  The drive control unit 39 controls the current supplied to the compressor motor 25 (drive of the compressor motor 25) by changing the frequency of the output signal applied to the compressor motor 25 (hereinafter referred to as drive frequency). In particular, in the present embodiment, as described above, the compressor motor 25 is driven at a constant drive frequency when the air conditioning load is small, and the capacity level set by the rotary switch 36 is supported. It is characterized in that the drive frequency of the compressor motor 25 is controlled so as not to exceed the current upper limit value.

  The operation of the drive control unit 39 will be specifically described. FIG. 6 is a graph showing a change with time of the drive frequency of the compressor motor 25. In addition, before the air conditioning system 1 is turned on, for example, the “high” capacity level is selected in advance by the rotary switch 36, and the air conditioning load at the beginning of the operation of the air conditioning system 1 is large. And

In this state, when the air conditioning system 1 is turned on at time T1, the drive control unit 39 refers to the current upper limit value table in the table storage unit 37, and the capability level set by the rotary switch 36. The current upper limit value I ₃ corresponding to (here, “strong” ability level) is derived. Then, as indicated by an arrow A in FIG. 6, the drive control unit 39 increases the drive frequency of the compressor motor 25. As a result, the current supplied to the compressor motor 25 and thus the current supplied to the outdoor unit 3 increase.

Here, the drive control unit 39 controls the drive frequency of the compressor motor 25 so that the current detected by the current detection unit 38 does not exceed the current upper limit I ₃ corresponding to the “strong” capability level. . That is, the drive control unit 39, when the current I detected by the current detection unit 38 exceeds the current limit I ₃ instantaneously, the drive frequency of the compressor motor 25 by reducing a small amount, the compressor motor current supplied to the 25, and by extension to implement fine adjustment of by reducing the current supplied to the outdoor unit 3 is below the current upper limit value I _3. Although the drive frequency of the compressor motor 25 is finely adjusted as described above, the compressor motor 25 is driven at a substantially constant drive frequency f ₁ as indicated by an arrow B in FIG.

Thereafter, as the temperature of the indoor air gradually approaches the target temperature and the air conditioning load decreases, the capacity required of the compressor 8 decreases, so that the drive control unit 39 is shown by an arrow C in FIG. , the driving frequency of the compressor motor 25 with a decrease in air-conditioning load, gradually reduced to the driving frequency f ₂ determined in advance.

When the air-conditioning load is minimized, as indicated by the arrow D in FIG. 6, the drive control unit 39 drives the compressor motor 25 at a constant driving frequency f _2.

As described above, in this embodiment, when the air conditioning load is small, the compressor motor 25 is driven at a constant drive frequency f ₂ , so that the energy efficiency is higher than that in the conventional technique in which operation and stop are repeated. Can be increased. That is, in the present embodiment, the compressor motor 25 is driven at the drive frequency f ₂ even during the pause period in the conventional technique in which the operation and the pause are repeated. In particular, energy efficiency can be improved as compared with the above-described prior art by not switching from operation to operation that requires a large amount of electric power.

  In addition, when the air conditioning load is relatively large, a plurality of upper limit values of the supply current to the outdoor unit 3 are set, and the desired current upper limit value can be manually set by the rotary switch 36, so that the indoor air can be cooled. The user can select the speed of warming (the time required to cool or warm the air to a desired temperature).

  In this case, the following modifications may be employed instead of or in addition to the embodiment.

  [1] Although the rotary switch 36 is provided in the first embodiment as an operation unit for manually setting the upper limit value of the current supplied into the air conditioning system 1, the present invention is not limited thereto, You may make it install in the form of a switch. Further, when the operation unit for manually setting the current upper limit value is separated from the remote controller, the operation unit may be configured to be connected to the indoor unit 2 by wiring in terms of appearance, or to the outdoor unit 3 It may be configured to be connected by wiring. Furthermore, the current limit value for the plurality of outdoor units 3 may be collectively changed by one rotary switch 36.

  [2] In the first embodiment, a plurality of capacity levels are set for the air conditioning capacity when the air conditioning load is large, but the air conditioning is smaller than the air conditioning capacity corresponding to the air conditioning load when the air conditioning load is minimized. Multiple ability levels may be set for the ability.

  [3] In the first embodiment, the user sets the upper limit value of the current supplied into the air conditioning system 1 using the rotary switch 36. However, the present invention is not limited to this configuration. The current upper limit value may be automatically set based on the environment.

  FIG. 7 is a diagram illustrating a configuration in which the current upper limit value is automatically set based on the environment of the air conditioning system 1. The embodiment shown in FIG. 7 is different from the first embodiment in that an environment detection unit 42 that detects the environment of the air conditioning system 1 is mounted, and other points are the first embodiment. Is substantially the same.

  The environment detection unit 42 is electrically connected to the control unit 24 and outputs environment information indicating the detected environment to the control unit 24. The control unit 24 sets an upper limit value of current based on this environmental information.

  As the environment detection unit 42, an outside air temperature sensor that detects the outside air temperature is assumed. In this case, for example, when the cooling operation is performed when the outside air temperature is relatively high, it is expected that the air conditioning load becomes relatively large at least at the beginning of the operation. Therefore, the drive control unit 39 sets the current upper limit value to be larger than that when the air conditioning load is small when the detected temperature of the environment detection unit 42 is higher than a predetermined threshold in the cooling operation. .

  Further, when the heating operation is performed when the outside air temperature is relatively low, it is expected that the air conditioning load becomes relatively large at least at the beginning of the operation. Therefore, the drive control unit 39 sets the current upper limit value to be larger than that when the air conditioning load is small when the temperature detected by the environment detection unit 42 is lower than a predetermined threshold in the heating operation. .

  As another example of the environment detection unit 42, a suction air temperature sensor that detects the temperature of the air sucked by the indoor unit 2 (an example of indoor air) is assumed. In this case, when the temperature difference between the temperature of the air sucked into the indoor unit 2 and the target temperature is relatively large, it is expected that the air conditioning load becomes relatively large at least at the beginning of operation. Therefore, when the temperature difference between the temperature detected by the environment detection unit 42 (intake air temperature sensor) and the target temperature is larger than a predetermined threshold, the drive control unit 39 sets the air conditioning load to be larger than when it is small. .

  FIG. 7 shows an example in which both the environment detection unit 42 and the rotary switch 36 are mounted on the air conditioning system 1 and the capability level when the air conditioning load is large can be set manually or automatically. This case includes a form in which only the environment detection unit 42 is mounted on the air conditioning system 1.

  [4] As in the modification [3], the current upper limit value is automatically set based on the state of the air conditioning system 1 in addition to the configuration in which the current upper limit value is automatically set based on the environment of the air conditioning system 1. A configuration to be set to is also assumed.

  For example, as shown in FIG. 3, when the air conditioning system 1 includes a heating degree sensor 44 that detects the heating degree of the discharge pipe 43 through which the refrigerant compressed by the compressor 8 passes, When the heating degree detected by the heating degree sensor 44 becomes smaller than a predetermined value, it is assumed that the current upper limit value is set to be larger than when the air conditioning load is small.

  Separately from this, at the time of execution of defrost (operation for removing frost adhered to the interior of the indoor unit 2), the current upper limit value is set to be larger than when the air conditioning load is small. As a result, the defrosting time can be shortened.

  Further, when a small air volume is set, the current upper limit value is set to be smaller than that when the air conditioning load is small so that the degree of superheat at the outlet of the indoor unit 2 is lower than when the air conditioning load is small. Good.

  [5] In the first embodiment, the driving frequency of the compressor motor 25 that drives the compressor 8 is used as a control parameter for controlling the current supplied to the outdoor unit 3, and a plurality of upper limit values for the current are set. Thus, a plurality of air conditioning capabilities of the air conditioning system 1 when the air conditioning load is large are provided. The air conditioning capability of the air conditioning system 1 depends not only on the compression capability of the compressor 8 but also on the ventilation capability of the indoor fan 6. Also changes. That is, even when the air conditioning load is large or small, the air at the same temperature is supplied into the room. Can be set to

  Therefore, when the air-conditioning load is large by setting the driving frequency of the motor 7 that drives the indoor fan 6 as a control parameter for controlling the current supplied to the outdoor unit 3 and setting a plurality of upper limit values for the current. A plurality of capacity levels are provided for the air conditioning capacity of the air conditioning system 1, and the motor 7 that drives the indoor fan 6 is driven by the same method as the control method of the first embodiment (control method shown in FIG. 6). You may make it control.

  In addition, by controlling the drive frequency of the compressor motor 25 that drives the compressor 8, the drive frequency of the motor 7 that drives the indoor fan 6 and the first embodiment that controls the air conditioning capability of the air conditioning system 1 are set. When compared with the present modification that controls the air conditioning capacity of the air conditioning system 1 by controlling, one has the following advantages over the other.

  That is, when there is a user near the air outlet after air conditioning, if the air blowing capacity is increased as in this modified embodiment, the possibility that a relatively strong wind will directly hit the user increases, and there is a concern that the comfort may be reduced. Is done. On the other hand, in the first embodiment, since the air blowing capacity does not change, there is almost no concern as described above.

  On the other hand, when the user in the room and the indoor unit 2 are relatively separated from each other, even if the compression capability of the compressor 8 is increased as in the first embodiment, the air after the air conditioning is It is difficult to get to where it is. On the other hand, in this modified embodiment, air after air conditioning is easily distributed to a place where there is a user who is relatively separated from the indoor unit 2 in order to increase the air blowing capability.

  Considering the above points, the first embodiment is suitable when the air conditioning system 1 targets air in a relatively small space for air conditioning, and conversely, in the present modified embodiment, the air conditioning system 1 is relatively This is suitable when air in a large space is to be air-conditioned.

It is a figure which shows the structure of 1st Embodiment of an air conditioning system. It is a block diagram which shows the structure of an air conditioning system. It is a figure which shows the circuit structure of the motor drive circuit part for compressors. It is a figure which shows the external appearance of a rotary switch. It is a figure which shows an electric current upper limit table. It is a graph which shows the time-dependent change of the drive frequency of a motor. It is a block diagram which shows the modification of a structure of an air conditioning system. It is explanatory drawing of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioning system 2 Indoor unit 3 Outdoor unit 6 Indoor fan 7 Indoor fan motor 8 Compressor 13 Outdoor fan 19 Outdoor fan motor 20 Compressor drive part 21 Indoor fan drive part 22 Outdoor fan drive part 23 Input operation part 24 Control part 25 Compression Motor motor 26 Compressor motor drive circuit section 28 Inverter circuit 33 Indoor fan motor drive circuit section 35 Outdoor fan motor drive circuit section 36 Rotary switch 37 Table storage section 38 Current detection section 39 Drive control section 42 Environment detection section 44 Heating Degree sensor

Claims (11)

A compressor for compressing the refrigerant;
A first motor for driving the compressor;
A condenser for condensing the refrigerant compressed by the compressor;
An evaporator for evaporating the refrigerant condensed by the condenser;
A blower for sending air generated by the operation of the condenser and evaporator into the room;
A second motor that drives the blower;
An inverter circuit unit for outputting AC power to at least one of the first motor and the second motor;
A first drive mode for outputting AC power having a predetermined first frequency from the inverter circuit unit when the air-conditioning load of the air-conditioning target space is outside a certain range based on a predetermined load; A drive control unit having a second drive mode for outputting, from the inverter circuit unit, AC power having a constant second frequency smaller than the first frequency when the air conditioning load is within the certain range ;
A current detection unit that repeatedly detects a sum of currents supplied from a commercial power source to each predetermined unit of the air conditioning system including the first or second motor;
A limit value storage unit that stores a plurality of types of limit values for the sum of currents supplied from the commercial power source to the units in the first drive mode;
The drive control unit selects a limit value according to the state of the air conditioning system from a plurality of limit values stored in the limit value storage unit in the first drive mode, and the current detection unit The frequency of the AC power is changed so that the detected current does not exceed the selected limit value, and the state is started until a predetermined time elapses after the main power supply of the air conditioning system is turned on When it is in a state, a limit value larger than the limit value set in the second drive mode is selected from the plurality of limit values stored in the limit value storage unit, and is detected by the current detection unit. An air conditioning system that changes the frequency of the AC power so that the current does not exceed the selected limit value . A compressor for compressing the refrigerant;
A first motor for driving the compressor;
A condenser for condensing the refrigerant compressed by the compressor;
An evaporator for evaporating the refrigerant condensed by the condenser;
A blower for sending air generated by the operation of the condenser and evaporator into the room;
A second motor that drives the blower;
An inverter circuit unit for outputting AC power to at least one of the first motor and the second motor;
A first driving mode in which AC power having a predetermined frequency for obtaining a driving force of the first or second motor with respect to a predetermined load with respect to an air-conditioning load in the air-conditioning target space is output from the inverter circuit unit; A drive control unit having a second drive mode for outputting AC power having a frequency for obtaining a driving force smaller than the driving force from the inverter circuit unit;
A current detection unit that repeatedly detects a sum of currents supplied from a commercial power source to each predetermined unit of the air conditioning system including the motor;
A limit value storage unit that stores a plurality of types of limit values for the sum of currents supplied from the commercial power source to the units in the first drive mode;
The drive control unit selects a limit value according to the state of the air conditioning system from a plurality of limit values stored in the limit value storage unit in the first drive mode, and the current detection unit The frequency of the AC power is changed so that the detected current does not exceed the selected limit value, and the state is started until a predetermined time elapses after the main power supply of the air conditioning system is turned on When it is in a state, a limit value larger than the limit value set in the second drive mode is selected from the plurality of limit values stored in the limit value storage unit, and is detected by the current detection unit. An air conditioning system that changes the frequency of the AC power so that the current does not exceed the selected limit value . A current limit value input selection unit for performing an input to selectively select the current limit value from a plurality of limit values stored in the limit value storage unit;
The drive control unit sets the frequency of the AC power so that a current detected by the current detection unit does not exceed a limit value selected by the current limit value input selection unit in the first drive mode. The air conditioning system according to claim 1 or 2 to be changed. It has an environment detection unit that detects the environment,
The drive control unit selects a limit value based on an environment detected by the environment detection unit from a plurality of limit values stored in the limit value storage unit in the first drive mode, and the current as detected by the detection unit current does not exceed a limit value thereof selected, the air conditioning system of claim 1 for changing the frequency of the AC power. The environment detection unit detects the temperature of the outside air,
The drive control unit selects a limit value based on the temperature detected by the environment detection unit from a plurality of limit values stored in the limit value storage unit in the first drive mode, and the current The air conditioning system according to claim 4 , wherein the frequency of the AC power is changed so that the current detected by the detection unit does not exceed the selected limit value. The environment detection unit detects the temperature of indoor air,
In the first drive mode, the drive control unit is configured to calculate a difference between a room air temperature detected by the environment detection unit and a target temperature from a plurality of limit values stored in the limit value storage unit. The air conditioning system according to claim 4 , wherein a limit value is selected based on the frequency, and the frequency of the AC power is changed so that the current detected by the current detection unit does not exceed the selected limit value. The first drive mode is a drive mode for outputting AC power having a frequency higher than the predetermined frequency when the air conditioning load is greater than the certain range.
The air conditioning system according to any one of claims 1 to 6 , wherein the limit value storage unit stores a limit value larger than a limit value set in the second drive mode. The state is a state in which the air conditioning system is performing a defrost operation,
The drive control unit selects a limit value larger than a limit value set in the second drive mode from a plurality of limit values stored in the limit value storage unit in the defrost operation execution state. The air conditioning system according to claim 1 or 2 , wherein the frequency of the AC power is changed so that the current detected by the current detection unit does not exceed the selected limit value. A heating degree detection unit for detecting the heating degree of the discharge pipe through which the refrigerant discharged from the compressor passes,
The state is a state where the heating degree detected by the heating degree detection unit is smaller than a predetermined value,
The drive control unit, when the degree of heating is smaller than a predetermined value, out of a plurality of limit values stored in the limit value storage unit, the limit value set in the second drive mode The air conditioning system according to claim 1 or 2 , wherein a larger limit value is selected, and the frequency of the AC power is changed so that the current detected by the current detection unit does not exceed the selected limit value. The air conditioning system according to any one of claims 1 to 9 , wherein the inverter circuit unit outputs AC power to the first motor that drives the compressor. The air conditioning system according to any one of claims 1 to 10 , wherein the inverter circuit unit outputs AC power to the second motor that drives the air blowing unit.

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