JP2911210B2 - Control device for air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention provides a refrigeration cycle in which a compressor, a condenser, a decompression device, and an evaporator are sequentially connected in a ring by a refrigerant pipe, and arbitrarily changes a hot water circulation amount. It has a hot water circuit in which a possible pump, a heating device, and a radiator are sequentially connected in a ring by a hot water pipe, and the outdoor unit includes at least a compressor, a condenser, and a pump and a heating device in the refrigeration cycle in the hot water circuit. The present invention relates to an air conditioner housed in the same outdoor unit, particularly to control of a hot water circulation pump.

(B) Prior art As an air conditioner having a refrigeration cycle and a hot water circuit, there has been an air conditioner described in Japanese Patent Application Laid-Open No. 57-117939. In this publication, the hot water circulation pump is simply turned on / off in accordance with the heating operation of the conditioned room or the operation / stop of the heating device.

(C) Problems to be Solved by the Invention In such a conventional pump control, the operation is simply turned on / off.
I used to do it. For this reason, in many cases, it is not possible to obtain a circulation amount of the hot water that matches the air-conditioning load, and in some cases, the air-conditioning capacity is insufficient or the excess capacity is wasted. Incidentally, it is conceivable to change the hot water circulation amount by extracting the speed adjusting tap from the motor winding for driving the pump, but in this case, the number of variable stages of the hot water circulation capacity is limited to the number of speed adjusting taps. However, pump capacity shortage and excess capacity could not be resolved.

In order to protect the pump, a temperature switch that operates at a predetermined temperature or higher is provided on the stator winding of the driving motor, and when the temperature of the motor becomes higher than the predetermined temperature, the power supply to the motor is stopped. Then, the operation of the pump was stopped. When the protection of the pump is performed simply by using the temperature switch, there is a problem that the operation of the pump is stopped even when the temperature is increased due to an overload.

Further, in an air conditioner having such a refrigeration cycle and a hot water circuit, an outdoor unit houses a compressor of the refrigeration cycle, a condenser, a heating device (composed of a burner and a heat exchanger) of a hot water circuit, and a pump. In this case, the volume of the outdoor unit is increased to accommodate the refrigeration cycle and the hot water circuit. That is, since the individual devices are relatively large, it is difficult to reduce the size of the outdoor unit. In this case, it is particularly difficult to reduce the size of the heat exchanger in consideration of its efficiency, and the burner generates a large amount of heat, so that the size of the heat exchanger is limited due to the influence on the devices arranged around the burner. Therefore, it is possible to reduce the size of the compressor and the pump. In order to reduce the size of the compressor, driving by an inverter is generally known as an effective means. The use of the inverter makes it possible to improve the performance due to the high rotation of the compressor, and accordingly, it is possible to reduce the size of the compressor itself. On the other hand, a rectifying and smoothing circuit for converting AC to DC is required. When driving a general household compressor, this rectifying and smoothing circuit should be at least 1.5KW
About a certain amount of output was required, and the volume was increased by this amount.

Next, it is conceivable to similarly increase the rotation speed of the pump to reduce the size. Generally, the pump is disposed near the water, and thus has a closed structure in consideration of water intrusion. Therefore, when the rotation speed is increased for downsizing, there is a problem that the heat dissipation of the electric motor is not sufficiently ensured and the temperature protection device frequently operates to interrupt the operation. Therefore,
Similarly, the pump has a limited size.

In order to solve such a problem, the present invention provides an air conditioner which achieves both high rotation speed and miniaturization of the pump to maximize the miniaturization of the pump and enables miniaturization of the outdoor unit. Things.

(D) Means for Solving the Problems The present invention provides a compressor, a condenser, a decompression device, and an evaporator that are sequentially driven by a three-phase AC output from a first inverter unit whose frequency can be arbitrarily changed. A refrigeration cycle connected in a ring by a pipe, and a hot water circuit in which a pump, a heating device, and a radiator are sequentially connected in a ring by a hot water pipe, and the evaporator housed in the indoor unit of the conditioned room. In the air conditioner configured to perform the cooling operation of the conditioned room by absorbing heat and perform the heating operation of the conditioned room by radiating heat from the radiator housed in the indoor unit of the conditioned room, the pump includes: Using a rotary pump driven by a three-phase induction motor,
The control device for the air conditioner includes a rectifying / smoothing unit for converting alternating current supplied from a commercial power supply into direct current power, a first wiring circuit for supplying the direct current power to the first inverter unit, A second inverter unit for converting the three-phase AC power into three-phase AC power, a wiring circuit for supplying three-phase AC power output from the second inverter unit to a three-phase induction motor of the pump, and a three-phase induction motor for the pump And a controller that changes the frequency of the three-phase AC power supplied to the power supply based on a predetermined rule.

Further, the present invention has a hot water circuit in which a pump, a heating device, and a radiator capable of arbitrarily changing a circulating amount of hot water are sequentially connected in an annular manner with a hot water pipe, and the radiator housed in the indoor unit of the conditioned room. In the air conditioner configured to perform the heating operation of the room to be conditioned by the heat radiation from, a rotary pump driven by an electric motor is used as the pump, and the control device of the air conditioner includes: A rotation speed control device that controls the rotation speed of the motor of the pump based on a given control signal, a temperature sensor that detects the temperature of the pump or the temperature of the winding of the motor, and a temperature detected by the temperature sensor. First
When the temperature is higher than or equal to, stop the operation of the pump,
When the temperature detected by the temperature sensor is lower than the first temperature and higher than the second temperature, a protection unit is provided for correcting the control signal to reduce the rotation speed of the pump.

Further, the present invention has a hot water circuit in which a pump, a heating device, and a radiator capable of arbitrarily changing a circulating amount of hot water are sequentially connected in an annular manner with a hot water pipe, and the radiator housed in the indoor unit of the conditioned room. In the air conditioner configured to perform the heating operation of the conditioned room by the heat radiation from, a rotary pump driven by a three-phase induction motor is used as the pump, and the control device of the air conditioner is An inverter unit for supplying three-phase AC power having a frequency corresponding to a given frequency signal to the three-phase induction motor, a temperature sensor for detecting a temperature of the pump or a temperature of a winding of the motor, When the temperature detected by the temperature sensor becomes equal to or higher than the first temperature, the operation of the pump is stopped, and when the temperature detected by the temperature sensor is lower than the first temperature and higher than the second temperature, three pumps are applied to the pump. Intercourse It is obtained and a protection unit that performs correction to decrease the frequency of the power to said control signal.

Further, the temperature sensor detects the temperature of the windings of the pump or the electric motor at predetermined intervals.

Further, a third temperature higher than the second temperature and lower than the first temperature is set, and the correction amount for lowering the rotation speed of the pump when the temperature detected by the temperature sensor is higher than the third temperature is: The correction amount is set to be larger than a correction amount for lowering the rotation speed of the pump when the temperature detected by the temperature sensor is lower than a third temperature.

(E) Operation By using the air conditioner controller configured as described above, when the pump for hot water circulation is overloaded and the temperature of the pump rises, the operating capacity of the pump is lowered to reduce the temperature. It is possible to avoid a rise.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing an embodiment of the present invention, in which 1 is an outdoor unit and 2 is an indoor unit, which are connected by refrigerant piping, hot water piping, and signal lines. Reference numeral 3 denotes a compressor, 4 denotes a condenser, 5 denotes a capillary tube, 6 denotes an evaporator, 7 denotes a muffler, and 8 denotes an accumulator, each of which is purely connected by a refrigerant pipe to constitute a refrigeration cycle. Reference numeral 9 denotes a service valve, and reference numeral 10 denotes a nipple, which is a connection port of a refrigerant pipe between the outdoor unit 1 and the indoor unit 2. Similarly, 11 is a service valve and 12 is a nipple, which is also a connection port of a refrigerant pipe.

The compressor 3 is a hermetic compressor having a three-phase induction motor as a drive source. The operating capability of the compressor can be changed by changing the rotation speed of the three-phase induction motor.
As means for changing the rotation speed of the compressor, it is generally known to change the frequency of AC power supplied to the compressor using an inverter device.

An outdoor fan 13 blows air to the condenser 4. 14
Is an indoor fan for blowing the air cooled by the evaporator 6 to the conditioned room. That is, the cooling operation can be performed.

By using the refrigeration cycle configured as described above, it is possible to perform the cooling operation by changing the operating capacity of the compressor 3 based on the difference between the temperature of the conditioned room and the set temperature.

15 is a burner, 16 is a hot water heat exchanger, 17 is a radiator, 18 is a pressure tank, 19 is a pump for hot water circulation,
They are connected in a ring using hot water piping. Therefore, since the hot water (antifreeze) heated by the hot water heat exchanger 16 by driving the pump 19 flows through the radiator 17, the indoor fan is driven to blow air to the radiator 17,
The heating operation of the conditioned room can be performed.

20 is the hot water inlet of the outdoor unit 1 and 21 is the indoor unit 2
The hot water outlets are connected by hot water pipes. Reference numeral 22 denotes a hot water outlet of the outdoor unit, and reference numeral 23 denotes a hot water inlet of the indoor unit, which are connected by a hot water pipe as described above.

The burner 15 can change the amount of combustion, and the solenoid valves 24, 2
Combining the opening and closing of 5, it is possible to obtain the combustion amount of 4 stages (stop, small, medium, large). Reference numeral 26 denotes a proportional control valve, which adjusts the combustion amount of the burner 15 by changing the fuel supply amount. Therefore, the amount of combustion of the burner 15 can be controlled widely by combining the solenoid valves 24 and 25 and the proportional control valve 26. 27 is an electromagnetic valve for controlling the supply of fuel, and 28 is a fuel intake.

The opening of the proportional control valve 26 is changed so that the detected temperature of the hot water thermistor 29 becomes a target value (60 ° C. or 80 ° C.).

By performing such control, the temperature of the hot water is always maintained at the target temperature even if the circulation amount of the hot water changes.

The radiator 17 is formed integrally with the evaporator 6,
The shape will be described with reference to the sectional view of the indoor unit shown in FIG. In FIG. 2, reference numerals 30 and 31 denote refrigerant pipes, which are connected to an evaporator. 32 and 33 are hot water pipes and radiators 1
Connected to 7. The evaporator 6 and the radiator 17 are integrally formed by a heat exchanger sharing fins.
The evaporator 6 is located on the windward side of the air passage created by the indoor fan 14, and the radiator 17 is located on the leeward side. Therefore, when cooling is performed by the evaporator 6 and heating is performed by the radiator 17 at the same time, the air in the conditioned room flows as shown by the solid line arrow, and the dehumidifying operation is performed. In addition, 34 is an air suction port, 35 is an air filter,
36 is a wind direction changing plate, and 37 is an air outlet. Numeral 46 denotes a solenoid valve which regulates the flow rate of hot water circulating in the indoor unit. The degree of opening of the electromagnetic valve 46 (the amount of circulation of hot water) is set based on the set temperature of the conditioned room and the room temperature so as to match the size of the air conditioning load.

Further, in FIG. 1, reference numeral 38 denotes a drain tank in which hot water (antifreeze) overflowing from the pressure tank 18 is stored. The hot water overflowing from the drain tank is discharged from the drain connection port. Reference numeral 40 denotes a pressurized water injection port, which is connected to a hot water pipe connecting the pump 19 and the heat exchanger 16 via a check valve 41. The pressurized water inlet 40 is connected to the outdoor unit 1
After the hot water pipe is connected between the hot water circuit and the indoor unit 2, the antifreeze liquid is injected into the hot water circuit. Reference numeral 42 denotes a connection port of the hot water mat 43, which is connected to a hot water pipe connecting the outdoor unit 1 and the indoor unit 2 via a thermal valve 44. The thermal valve 44 is opened when the temperature detected by the temperature sensor 45 reaches a set value (60 ° C.), and the hot water mat
Hot water supply to 43 is started. This warm water mat is laid on the floor of the conditioned room, and can provide a floor heating effect. Note that the warm water mat 43 is removable. The hot water mat 43 is supplied with hot water having a lower temperature than the hot water supplied to the radiator 17. Reference numeral 47 denotes a bypass pipe, which is connected between the outlet of the heat exchanger 16 and the inlet of the pressure tank 18 in the hot water circuit. This bypass pipe 47
Is thinner than the piping of the hot water circuit, and when the solenoid valve 46 of the indoor unit is fully closed and the solenoid valve 44 is opened, the temperature of the hot water circulating in the hot water mat 43 can be maintained at 60 degrees or more. It is thickness. That is, the thickness of the bypass pipe 47 is such that the hot water can be circulated to the hot water mat 43 and the hot water can be heated by the burner.

FIG. 3 is an electric circuit diagram used for controlling the system shown in FIG. In this figure, reference numeral 50 denotes a microprocessor for controlling the operation of the indoor unit, and the microprocessor 50 obtains operating power from a power supply unit 51. The power supply unit 51 obtains electric power from a commercial AC power supply through a current fuse 52 and a plug 53.The power supply unit 51 rectifies and smoothes the AC power, controls the DC power to a predetermined DC voltage, and controls the microprocessor 50 and the power transistor module 54. To supply. The power transistor module 54 includes a plurality of switching elements connected in a three-phase bridge, and turns on / off the switching elements based on a signal corresponding to the rotation angle of the indoor fan 14 (driven by a DC brushless motor). The rotation of the DC motor is maintained by sequentially changing the energizing pattern to the DC motor by changing the combination. Therefore, the rotation of the indoor fan 14 is maintained.

Reference numeral 55 denotes a step motor whose rotation angle is determined by the number of pulses from the microprocessor 50. The step motor 55 is mounted to change the angle of the wind direction change plate 36 of the indoor unit. Therefore, the wind direction can be changed by changing the rotation angle of the step motor.

Reference numeral 56 denotes a wireless signal receiving unit which receives a wireless signal from the remote controller 57 and outputs a received signal to the microprocessor 50. Remote controller
From 57, an ON / OFF signal of the air conditioner, a signal indicating a room temperature set value, a signal for switching between cooling and heating, a signal for setting the air flow rate of the indoor fan, and the like are transmitted in accordance with a user operation.

Reference numeral 58 denotes a switch, which is a switch for switching the air conditioner between a total stop, a test run, a normal run, and the like.

59 and 60 are temperature sensors, and the evaporator 6 of the indoor unit.
And the temperature of the conditioned room.

The microprocessor 50 determines the magnitude of the load of the conditioned room by comparing the temperature of the conditioned room detected by the temperature sensor with the set temperature, and outputs a signal such that an operation capability corresponding to the magnitude of the load is obtained. Is output to the outdoor unit. This signal is converted to a serial signal by the serial signal circuit 61 and then transmitted to the outdoor unit. Further, the microprocessor 50 controls the amount of air blown by the indoor fan 14 automatically based on the difference between the room temperature and the set temperature to perform comfortable air conditioning.

Next, in the outdoor unit, reference numeral 62 denotes a microprocessor for controlling the operation of the outdoor unit, and a serial signal circuit.
A signal is received from the microprocessor 50 via 63.

Reference numeral 64 denotes a power supply unit, which receives power from a commercial power supply in common with the power supply unit 51 from the plug 53 of the indoor unit. After rectifying and smoothing the AC power, the power supply unit controls and outputs a predetermined DC voltage to a predetermined DC voltage. Things.

Reference numeral 65 denotes a three-phase inverter circuit which receives supply of the DC voltage (DC 280 [V]), and connects six power transistors in a three-phase bridge. ON / OFF of these six transistors is controlled by a signal from the microprocessor 62. The compressor 3 is connected to the output of the three-phase inverter circuit 65 and is driven by three-phase AC power output from the three-phase inverter circuit 65. Since a three-phase induction motor is used as a drive source of the compressor 3, the capability of the compressor 3 can be changed by changing the frequency of AC power supplied to the three-phase induction motor (compressor). In order to change the frequency of the AC power, the ON / OFF patterns of the six transistors may be changed. The ON / OFF pattern is calculated by the microprocessor 62 based on a generally known PWM theory. Therefore, the microprocessor 62 can control the frequency of the AC power supplied to the compressor based on the signal sent from the microprocessor 50 of the indoor unit so that the necessary performance can be obtained.

Reference numeral 66 denotes a switch unit for controlling the operation of the drive motor of the outdoor fan 13, and the operation of the switch unit is performed by a signal from the microprocessor 62. Since a brushless DC motor is used for the electric motor for the outdoor fan, the switch unit 66 changes the DC voltage applied to the electric motor based on a signal from the microprocessor 62 to control the rotation speed of the electric motor, that is, the air flow of the outdoor fan. Is what you do.

Reference numeral 67 denotes a pump inverter, which converts DC power supplied from the power supply unit 64 into AC power having a predetermined frequency. The difference between the inverter unit 67 and the above-described three-phase inverter circuit 65 is that the inverter unit 65 has a three-phase inverter circuit 65 and a controller unit that creates ON / OFF signals of transistors based on PWM theory, and a pump 19. In that it is provided with a protective part. Therefore, it is possible to output three-phase AC power of a desired frequency only by supplying a desired frequency signal to the inverter unit 67. The pump 19 is a rotary pump having a three-phase induction motor as a drive source. The pump 19 is driven by changing the rotation speed of the motor (frequency of AC power applied to the motor).
19 hot water circulation capacity can be changed. Also pump
In 19, a motor and a pump are provided in separate spaces to prevent hot water from entering the motor, and the motor and the pump are connected by a permanent magnet.

Reference numeral 68 denotes a temperature sensor which detects the temperature of the pump 19, for example, the temperature of the stator winding of the driving motor. The protection section of the inverter section 67 performs a predetermined protection operation when the temperature becomes higher than a set value. The protection section performs a predetermined protection operation when a current flowing through the motor becomes higher than a predetermined value. These protection operations will be described later.

Reference numeral 69 denotes a burner control unit that controls the combustion amount of the burner 15, the circulation amount of the pump 19, and the opening and closing and opening of each solenoid valve in response to a signal from the microprocessor 62 to circulate hot water. It is.

The control of the burner control unit 69 is performed so that the temperature of the hot water detected by the temperature sensor 29 shown in FIG. 1 is set to 80 degrees (or 60 degrees when the capacity selection is switched) so that the solenoid valves 24-27 are controlled.
The opening and closing and opening of the burner are controlled to change the burner combustion amount.
When the set value of the hot water temperature is 80 degrees, the frequency of the AC power applied to the pump 19 is set to the first frequency, and when the set value is 60 degrees, the frequency of the AC power applied to the pump 19 is set to the second frequency ( <1st set frequency). When the hot water setting is 80 degrees and there is a signal to use the hot water mat 43, the solenoid valve 44 is turned on when the hot water temperature detected by the temperature sensor 45 (the hot water temperature returned from the indoor unit) becomes 60 degrees or more. It is opened to supply hot water to the hot water mat 43. When there is no signal for setting the hot water temperature to a set value and only a signal for using the hot water mat 43, the combustion amount of the burner is controlled so that the hot water temperature detected by the temperature sensor 45 becomes 60 degrees. That is, hot water mat
It is in a state of driving only 45. In this case, the solenoid valve
While opening 44, the electromagnetic valve 46 provided in the hot water pipe of the indoor unit is fully closed. The AC power applied to the pump 19 is set to the second frequency.

FIG. 4 is an electric circuit diagram of the inverter section 67 for controlling the operation of the pump 19. In this figure, reference numeral 80 denotes a microprocessor for calculating a pattern of an ON / OFF signal to be supplied to a switching element mainly based on a PWM theory. Terminals 1 and 2 receive an H / L voltage level signal. Terminals 3 and 4 receive a frequency signal, and the interface 81
The frequency signal is supplied to the microprocessor 80 via the. Reference numeral 82 denotes a three-phase inverter circuit, in which six switching elements form a three-phase bridge and pump three-phase AC power.
It supplies 19 induction motors. The ON / OFF state of the six switching elements is switched by an ON / OFF signal from the microprocessor 80. Reference numeral 83 denotes a buffer circuit for amplifying the power of the ON / OFF signal from the microprocessor 80 and for improving the followability of the ON / OFF switching operation by accelerating the discharge of the accumulated charge of the switching element. Reference numeral 84 denotes a shunt resistor, which detects a change in voltage between both ends of the resistor to detect a DC current value flowing through the three-phase inverter circuit 82. Reference numeral 85 denotes an A / D (analog / digital) converter, which converts the voltage between both ends of the shunt resistor 84 into a digital value and outputs the digital value to the microprocessor 80. The microprocessor 80 calculates a current value based on the digital value. 86,8
Reference numeral 7 denotes an arbitrarily settable variable resistor for setting the actual values of the first frequency and the second frequency. The microprocessor 80 inputs the values of the variable resistors 86 and 87 and sets the corresponding frequency value. Therefore, when the first frequency is specified, ON / OFF such that AC power of a frequency corresponding to the value set by the variable resistor 86 is obtained.
A signal is output, and when the second frequency is specified, an ON / OFF signal is output such that AC power of a frequency corresponding to the value set by the variable resistor 87 is obtained. For example, the first frequency is set to 130 Hz, and the second frequency is set to 60 Hz.

FIG. 5 is a flowchart showing a main operation of the microprocessor 80 shown in FIG. In this figure, first, a reset operation and initial settings are performed in step S1. Next, in step S2, the H / L of the voltage levels of the terminals 1 and 2 is determined, and the process proceeds to any of steps S3 to S6. In step S3, acceptance of signals supplied to terminals 3 and 4 is permitted, and
The signal input from 3 and 4 is referred to as a frequency signal F. Step S
In 4, the frequency signal F corresponding to the set value of the variable resistor 86 is 130 Hz. In step S5, a frequency of 60 Hz corresponding to the set value of the variable resistor 87 is set as the frequency signal F. In step S6, the frequency 130 Hz corresponding to the set value of the variable resistor 86
Is a frequency signal F. Next, in step S7, the temperature T of the pump 19 (the temperature of the stator winding of the induction motor) and the current I flowing through the inverter circuit 82 are input. In step S8, it is determined whether the temperature T is equal to or higher than the temperature at which the temperature protection control is required. When the temperature protection control is required, the process proceeds to step S9. In step S9, the value of the correction value α is set depending on which of the zones shown in FIG. 6 the temperature T is in. As shown in FIG. 6, this zone is divided into three zones, Zone A, Zone B and Zone C, at temperatures of 94 ° C., 104 ° C. and 124 ° C. The sizes of the B zone and the C zone are different between when the temperature rises and when the temperature falls. Zone A is a zone where the pump is stopped immediately (restart after one minute), Zone B is a zone where α is corrected (a zone where the frequency is lowered), and this correction is performed when α = T> 110 ° C. It is 5 Hz / 40 seconds, otherwise α = 2 Hz / 40 seconds. After obtaining the correction value α in this manner, the correction of F = F−α is performed in step S10.

In step S11, it is determined whether the current I is equal to or more than a predetermined value. This predetermined value is set based on the magnitude of the output of the pump. When the current I is equal to or more than the predetermined value, the process proceeds to step S12, and the operation of the pump is stopped. Next, one minute after the stop of the pump, the pump is restarted in step S13. After such protection operation proceeds to enter the three-phase AC power frequency F ₀ of being output from the current inverter circuit 82 to a step S14. Then step S15, and compares the frequency signal F and the current frequency F ₀ at step S16, the process proceeds to either step S17~ step S19. In these steps, the frequency to be output next is increased or decreased by 1 Hz. When the next output frequency is determined, step S2
An ON / OFF signal pattern that can obtain AC power of this frequency at 0 is output to the inverter circuit 82.
In step S20, the ON / OFF signal is continuously output, so that continuous three-phase AC power can be obtained.

When the air conditioner configured as described above is used, the cooling operation performs the cooling operation using a refrigeration cycle, and performs the cooling operation by circulating hot water when performing the heating operation. In addition, if the heating operation is performed while the refrigeration cycle is operating, the dehumidification operation of the conditioned room can be performed. At this time, the temperature of the hot water circulating in the hot water circuit is set to 60 degrees.

In addition, when the temperature of the pump, that is, the temperature of the electric motor increases when the pump is operated to circulate hot water during the heating operation, the rotation speed of the electric motor can be reduced to suppress the temperature increase of the pump. . Therefore, the pump can be continuously operated without stopping. As described above, by correcting the rotation speed of the pump according to the temperature of the pump, it is possible to prevent the pump temperature from rising and stopping the operation of the pump even when the size of the pump is reduced and the rotation speed is increased.

Further, the rectifying and smoothing circuit used in the inverter circuit of the compressor is shared with the inverter circuit for the pump, so that the increase in the volume of the rectifying and smoothing circuit that occurs when the drive of the pump is converted to an inverter is eliminated. .

(G) Effect of the Invention As described above, the present invention has a hot water circuit in which a pump, a heating device, and a radiator capable of arbitrarily changing the amount of hot water circulation are sequentially connected in a ring with hot water pipes, and a conditioned room. In the air conditioner configured to perform the heating operation of the conditioned room by the heat radiation from the radiator housed in the indoor unit, a rotary pump driven by an electric motor is used as the pump. A control device for controlling the rotation speed of the motor of the pump based on a given control signal; a temperature sensor for detecting the temperature of the pump or the temperature of the windings of the motor; When the temperature detected by the temperature sensor is equal to or higher than a first temperature, the operation of the pump is stopped. When the temperature detected by the temperature sensor is lower than the first temperature and higher than the second temperature, the pump is stopped. Rotation speed A protection unit for performing a correction for lowering the control signal, so that even if the temperature of the winding of the electric motor rises, this temperature is kept at the first level.
If the temperature is equal to or lower than the temperature, the rotation speed of the pump is reduced without stopping the operation of the pump to prevent the temperature of the electric motor from rising. That is, the number of rotations of the pump is reduced so that the temperature of the electric motor does not exceed the second temperature, and the operation of the pump with high capacity can be continued without stopping the operation of the pump.

By controlling in this manner, the amount of circulation of hot water increases when the pump is operating at a high speed, so that a pump having a smaller rated output can be used. That is, the size of the pump can be reduced.

In addition, when the electric motor for driving the pump is driven by the inverter, the DC power supply for the inverter can be shared with the drive power supply for the compressor. This can also solve the problem of increase in the number of outdoor units, and can contribute to downsizing of the outdoor unit. Therefore, by combining the inverter drive of the compressor and the inverter drive of the pump, the outdoor unit of the air conditioner can be miniaturized to a practical range, and the installation work and transportation of the outdoor unit can be easily performed. .

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, FIG. 2 is a sectional view of the indoor unit shown in FIG. 1, FIG. 3 is an electric circuit diagram used for controlling the system shown in FIG. 4 is an electric circuit diagram of an inverter unit for controlling the operation of the pump shown in FIG. 1, FIG. 5 is a flowchart showing main operations of the microprocessor shown in FIG. 4, and FIG. 6 is used for temperature control. It is explanatory drawing of a zone. 1 ... outdoor unit, 2 ... indoor unit, 3 ... compressor, 15 ... burner, 19 ... pump, 68 ... temperature sensor.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F24F 11/02

Claims (5)

(57) [Claims] 1. A refrigeration system comprising a compressor, a condenser, a decompression device, and an evaporator driven by a three-phase alternating current output from a first inverter unit whose frequency can be arbitrarily changed. It has a cycle, a pump, a heating device, and a hot water circuit in which a radiator is sequentially connected in a ring with a hot water pipe. The cooling operation of the conditioned room is performed by absorbing heat of the evaporator housed in the indoor unit of the conditioned room. In addition, in the air conditioner configured to perform the heating operation of the conditioned room by heat radiation from the radiator housed in the indoor unit of the conditioned room, the pump is driven by a three-phase induction motor. Using a rotary pump,
The air conditioner control device includes a second inverter unit that supplies three-phase AC power of an arbitrary frequency to the pump, and a rectifying and smoothing unit that converts AC supplied from a commercial power supply into DC power. A power supply unit for supplying DC power to the first inverter for driving the compressor and the second inverter for driving the pump, and an overcurrent of electric power supplied to the induction motor for driving the pump when the induction motor is overheated or to the motor And a control unit that controls the pump to continue operating while reducing the three-phase AC power supplied from the second inverter unit to the pump driving induction motor by reducing the frequency. Air conditioner. 2. A radiator housed in an indoor unit of a room to be conditioned having a hot water circuit in which a pump, a heating device, and a radiator capable of arbitrarily changing a circulating amount of hot water are sequentially connected in a ring by a hot water pipe. In the air conditioner configured to perform the heating operation of the conditioned room by the heat radiation from, a rotary pump driven by an electric motor is used as the pump, and the control device of the air conditioner includes: A rotation speed control device that controls the rotation speed of the motor of the pump based on a given control signal, a temperature sensor that detects the temperature of the pump or the temperature of the winding of the motor, and a temperature detected by the temperature sensor. When the temperature becomes equal to or higher than the first temperature, the operation of the pump is stopped, and when the temperature detected by the temperature sensor is lower than the first temperature and higher than the second temperature, the control for reducing the rotation speed of the pump is performed by the control. signal Control device for an air conditioner characterized by comprising a protection unit that performs. 3. A radiator housed in an indoor unit of a conditioned room, having a hot water circuit in which a pump, a heating device, and a radiator capable of arbitrarily changing the amount of circulating hot water are sequentially connected in an annular manner by a hot water pipe. In the air conditioner configured to perform the heating operation of the conditioned room by the heat radiation from, a rotary pump driven by a three-phase induction motor is used as the pump, and the control device of the air conditioner is An inverter unit for supplying three-phase AC power having a frequency corresponding to a given frequency signal to the three-phase induction motor, a temperature sensor for detecting a temperature of the pump or a temperature of a winding of the motor, The operation of the pump is stopped when the temperature detected by the temperature sensor becomes equal to or higher than the first temperature, and when the temperature detected by the temperature sensor is lower than the first temperature and higher than the second temperature, three pumps are applied to the pump. Phase exchange Control device for an air conditioner characterized by comprising a protection unit that performs correction to decrease the frequency of force to the control signal. 4. The control device for an air conditioner according to claim 2, wherein said temperature sensor detects a temperature of said pump or a winding of said electric motor at predetermined intervals. 5. A correction for setting a third temperature higher than the second temperature and lower than the first temperature to lower the rotation speed of the pump when the temperature detected by the temperature sensor is higher than the third temperature. 4. The air conditioner according to claim 3, wherein the amount is set to be larger than a correction amount for lowering a rotation speed of the pump when a temperature detected by the temperature sensor is lower than a third temperature. 5. Control device.