JPH0137657B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a separate air conditioner in which an outdoor unit equipped with a compressor whose capacity can be controlled is connected to an indoor unit to perform cooling or heating.

Conventionally, a typical air conditioner controls a single-speed refrigerant compressor on and off depending on the magnitude of the temperature difference between a set temperature and an actual room temperature. For this reason, it was inevitable that some degree of unevenness would occur in controlling the room temperature, resulting in a lack of comfort. Additionally, due to the large current generated when the compressor is started, equipment costs tended to be relatively high during power distribution work.

Furthermore, in the case of a separate type, the methods for supplying power and operating the indoor and outdoor units are as follows: (i) The indoor unit and outdoor unit are connected via a commercial power line and the outdoor unit is controlled.

(ii) A method in which the outdoor unit has a dedicated commercial power source and the power to the outdoor unit is directly turned on and off using a lower voltage operating signal than the indoor unit.

(iii) A method in which the outdoor unit has a dedicated power supply, its control circuit is always energized, and the outdoor unit is precisely operated using low-voltage signals from the indoor unit.

etc. were hot. Among these, in (i), the wiring between the indoor unit and the outdoor unit is a commercial power line, and the operation of the outdoor unit is also performed using the commercial power line, so wiring work is required due to restrictions in technical standards. Not only is this troublesome, but it can also cause noise interference to other equipment. Method (ii) can solve the problem of (i) above, but since the operation of the outdoor unit is turned on and off at the same time when the operation signal from the indoor unit is turned on and off, control operations are required for the safety of the equipment. It was difficult to carry out the process in detail. In addition, although the method (iii) allows for fine-grained control, it has drawbacks such as shortening the lifespan of equipment, unsafe maintenance, and a negative impact on energy conservation because it requires constant energization.

The present invention controls the heating and cooling capacity continuously or in multiple stages according to the load, and enables stable startup and operation of the compressor.
Perform a shutdown operation, set the wiring between the indoor and outdoor units to low voltage, and during normal operation stoppages, turn off all power to the outdoor units, and if an abnormality occurs in the compressor control, The purpose is to improve the comfort of air conditioners, the safety and reliability of equipment, and the economic efficiency by preventing the spread of failures and ensuring that indoor units display abnormal conditions. .

Next, an embodiment of a separate air conditioner according to the present invention will be described based on the accompanying drawings.

FIG. 1 is a configuration diagram for cooling. In the figure, 1 is an outdoor unit and 2 is an indoor unit. 3 is a compressor whose capacity can be controlled, 4 is an outdoor heat exchanger, 5 is an outdoor fan, 6 is an expansion valve that adjusts the amount of throttling of the refrigerant, 7 is an indoor heat exchanger, and 8 is an indoor fan. form a cycle. 9 is a power supply for indoor unit 2, 10 is an indoor control circuit, 1
1 is the power supply for outdoor unit 1 (three-phase here), 1
2 is an outdoor control circuit.

Next, FIG. 2 shows an electric circuit in the configuration of FIG. 1. When the operation switch 13 of the indoor unit 2 is turned on, power is supplied from the power supply 9 to rotate the indoor fan 8, and at the same time, the DC power supply voltage is outputted from the DC power supply circuit 14 as the operation signal _VD . Further, the temperature difference signal circuit 15 generates a temperature difference signal V _T proportional to the difference between the room temperature detected by the room temperature detector 16 and the temperature set by the room temperature setting device 17. Both the operating signal V _D and the temperature difference signal V _T are input to the outdoor control circuit 12 . V _D is applied to the coil 23 of the self-holding relay via the diode 25 of the self-holding circuit 22 . The contact 24 of this relay is closed, and the DC power supply circuit 20 is energized and outputs the DC power supply voltage V _CC , which is applied to the arithmetic circuit 21 and the self-holding circuit 22 . The arithmetic circuit 21 is
Since the operating signal V _D is input and its value is on (high level), the self-holding circuit V _H is output at high level. Once this V _H becomes high level, the operation signal is
Even when _VD is turned off, it does not go to low level immediately. Now, when the self-holding signal V _H becomes high level, the transistor 26
and 27 are turned on, and the DC power supply voltage V _CC is applied via the diode 28 to the coil 23 of the self-holding relay.
is applied, and this relay remains on thereafter.

Next, the arithmetic circuit 21 turns on the auxiliary relay coil 29, closes its contacts 30, and switches the switch 31
is turned on to energize the compressor control circuit 34.
Through the above operations, the compressor 3 is ready to operate.

On the other hand, the temperature difference signal V _T is input to the arithmetic circuit 21 in the same way as the operation signal V _D , and is converted into a rotation speed setting signal V _N suitable for variable speed operation of the compressor 3 according to the temperature difference. Depending on _N , compressor control circuit 3
4 drives the compressor 3 at variable speed and performs capacity control.
As a variable speed drive method for the compressor 3, the compressor control circuit 34 is configured as a variable frequency power supply and controls the output frequency in response to the rotation speed setting signal _VN .

Furthermore, the starting and stopping operations of the compressor 3 are performed by so-called soft start and soft stop, that is, by gently changing the speed, in order to improve the safety of the equipment and reduce noise.

While the compressor 3 is operating, the outdoor fan 5 is operated, so the arithmetic circuit 21 turns on and off the fan relay coil 32 in conjunction with the rotation speed setting signal _VN , and closes the contact 33. The outdoor fan 5 is controlled by opening and closing.

Through the above-described operations, the rotation speed of the compressor 3 is controlled to correspond to the temperature difference signal _VT , and the room temperature is maintained equal to the set temperature.

Note that when the arithmetic circuit 21 issues a rotation speed setting signal V _N that changes the compressor 3 from an operating state to a stopped state, the value of the temperature difference signal V _T remains unchanged for a certain period of time thereafter, for example, one minute. Regardless, compressor 3
I am trying to maintain a stopped state. this is,
If you try to restart the compressor after the compressor has stopped and before the refrigerant cycle has reached almost equilibrium, the required starting torque will be excessive, resulting in inability to start or an adverse effect on the power supply, which is not desirable for the safety of the equipment. Such a stop time is provided.

After performing the control as described above, cooling operation is no longer necessary, and operation switch 1 of indoor unit 2 is turned off.
3 is turned off, the operation signal V _D and temperature difference signal V _T
becomes zero. Therefore, the arithmetic circuit 21 issues a rotation speed setting signal V _N to the compressor control circuit 34 for stopping the compressor 3, and the rotation speed of the compressor 3 gradually decreases and stops. Thereafter, after the above-mentioned time period for the refrigerant cycle to reach almost equilibrium has elapsed, the arithmetic circuit 21
turns off the power to the auxiliary relay coil 29 and sets the self-holding signal _VH to a low level.
This turns off transistors 26 and 27 and relay coil 23 is no longer energized, so its contacts 24 are open. As a result, the power to the outdoor control circuit 12 is completely cut off, and the outdoor control circuit 12 is brought to a stopped state. Thereafter, when the operation switch 13 of the indoor unit 2 is turned on again, the same operation as described above will be performed.

The above is a normal operation, but next, the compressor control circuit 34 is equipped with an overcurrent detection circuit due to its own failure, a short circuit in the drive motor winding of the compressor 3, a mechanical lock, or the like. In the event of an abnormality in which this circuit detects an overcurrent, the compressor control circuit 34 instantly stops power supply to the compressor 3 to prevent the spread of failure to its component parts such as semiconductors, and also to Emit an abnormal signal V _P. Arithmetic circuit 2
1 turns off the power to the auxiliary relay coil 29, opens its contacts 30, and completely turns off the power to the compressor control circuit 34 when the abnormality signal V _P is input, and also outputs the abnormality display signal V _L is output to the indoor unit 2, and the self-holding signal _VH is always maintained at a high level even if the operation signal _VD becomes zero thereafter. By this operation, the light emitting diode 19 in the abnormality display circuit 18 provided in the indoor unit 2 is activated in response to the abnormality display signal _VL . For example, when the abnormality display signal _VL is set high and low at a predetermined cycle, the light emitting diode 19 blinks accordingly, indicating that an abnormality has occurred in the outdoor unit 1. This display allows you to recognize abnormalities indoors. Furthermore, after that, the operation switch 13
Even when the compressor 3 is turned on and off, the outdoor control circuit 12 is always in a energized state, but power is not supplied to the compressor 3 at all, so it is safe. Moreover, whenever the operation switch 13 is turned on, the light emitting diode 19 indicates an abnormality, so that the need for inspection of the outdoor unit 1 can be communicated. If an abnormality message appears, turn off the operation switch 13, open the hand switch of the power supply 11 for the outdoor unit 1, etc. to ensure that the power is turned off, and perform inspection and repair to ensure a complete recovery. Then turn the power back on.

FIG. 3 shows the abnormality display circuit 18 in FIG.
This is another embodiment of the abnormality display circuit 1 shown in this figure.
8' consists of a resistor 35 and a light emitting diode 19.
According to this configuration, when the abnormality display signal V _L is at a high level or repeats high and low levels at a predetermined period, the light emitting diode 19 switches the operation switch 1
Even if 3 is off, it lights up or blinks to indicate that there is an abnormality. Therefore, in this case, even if an abnormality occurs at the same time as the operation switch 13 is turned off,
It is possible to reliably display an error message and prevent a malfunction from being left unattended for a long time.

The embodiments of the separate air conditioner of the present invention have been described above with reference to the accompanying drawings, but similar effects can be achieved with the configurations described below.

(1) Not only for cooling only, but also for heat pump type. In this case, a low voltage signal is sent from the indoor unit 2 to the outdoor unit 1 in response to switching between cooling and heating.
The refrigerant may be sent to the refrigerant cycle to control switching of four-way valves, etc. in the refrigerant cycle.

(2) The compressor control circuit 34 is configured with a variable frequency power supply, and can be driven at a continuously variable speed by using a DC motor as a drive motor of the compressor 3, so-called a transistor motor or the like. In addition to driving the compressor 3 at a continuously variable speed, it is also possible to control the capacity by changing the rotation speed in multiple stages.

(3) This device has been described for the case where there is one outdoor unit 1 and one indoor unit 2, but it can also be realized in a so-called multiplex type case where multiple indoor units are connected to one outdoor unit. obtain. In this case, the operation signal V _D is output from each indoor unit, and the self-holding relay coil 23 is energized by their logical sum, and the temperature difference signal V _T is the sum or average value of the two. , or the maximum value, etc., and can be converted to the rotation speed setting signal V _N by processing appropriate for the intended use. Further, the abnormality display circuit 18 is
Although it does not necessarily have to be provided in all indoor units, if possible, if it is provided in all, abnormalities can be recognized in any indoor unit, which is convenient for operation and maintenance.

As described above, the present invention has the following excellent effects.

(b) Since the outdoor unit and outdoor unit are each equipped with an independent power supply, there is no need for commercial power wiring between the outdoor and indoor areas, which simplifies the wiring work and reduces noise caused by the wiring to other equipment. can be avoided.

(b) Since the outdoor unit and indoor unit are connected by low-voltage wiring insulated from the commercial power supply, it is possible to avoid problems caused by the commercial power supply wiring, and even after each fan or compressor is stopped. It can easily be self-retained for a predetermined period of time.

(c) During normal operation, even if there is a stop signal from the indoor side, the power to the outdoor side is not cut off immediately, but after a predetermined time, so the arithmetic circuit is energized for a predetermined time and the power from the indoor side is turned off. Even if the operation signal is sent again immediately after the operation stop signal, the compressor does not restart immediately.

(d) In the event of an abnormality, the compressor is stopped by the compressor control circuit itself and the arithmetic circuit is energized, so the compressor stops immediately while the
As in the case of (c), the compressor will not restart immediately.

(E) When an abnormal condition occurs in the compressor system, the abnormal condition is immediately displayed on the indoor abnormality display circuit, so the safety of the equipment is always ensured.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a separate air conditioner according to the present invention, FIG. 2 is an electric circuit diagram with the configuration shown in FIG. 1, and FIG. 3 is a part of the electric circuit diagram (abnormal FIG. 4 is a diagram showing another example of the display circuit (display circuit). 1... Outdoor unit, 2... Indoor unit, 3... Compressor, 4... Outdoor heat exchanger, 5... Outdoor fan, 6...
Expansion valve, 7... Indoor heat exchanger, 8... Indoor fan, 9
...Indoor unit power supply, 10...Indoor control circuit, 1
1...Power supply for outdoor unit, 12...Outdoor control circuit,
13... Operation switch, 14... DC power supply circuit (indoor unit), 15... Temperature difference signal circuit, 16... Room temperature detector, 17... Room temperature setting device, 18, 18'... Abnormality display circuit, 19... Light emitting diode (display element) ),
20... DC power supply circuit (outdoor unit), 21... Arithmetic circuit, 22... Self-holding circuit, 23... Self-holding relay coil, 24... Self-holding relay contact, 2
5... Diode, 26... Transistor, 27... Transistor, 28... Diode, 29... Auxiliary relay coil for switch, 30... Auxiliary relay contact for switch, 31... Switch, 32... Relay coil for outdoor fan, 33... For outdoor fan Relay contact, 34...Compressor control circuit, 35...Resistance, V _D ...Operation signal, V _T
...Temperature difference signal, V _H ... Self-holding signal, V _L ... Abnormality display signal, V _N ... Rotation speed setting signal, V _P ... Abnormal signal.

Claims (1)

[Claims] 1. In a separate air conditioner consisting of an outdoor unit 1 and an indoor unit 2, the indoor unit 2 has a DC power supply circuit 14 and a temperature difference generator that generates a signal corresponding to the difference between the room temperature and the set temperature. The outdoor unit 1 includes a signal circuit 15 and an abnormality display circuit 18. The outdoor unit 1 includes a DC power supply circuit 20, an arithmetic circuit 21, a self-holding circuit 22, and a compressor control circuit 34. , a means for driving the compressor 3 at variable speed and an arithmetic circuit 2 for generating an abnormal signal when an abnormal condition occurs.
The self-holding circuit 22 has means for self-holding by energizing the DC power supply circuit 20 in response to the operation signal V _D from the DC power supply circuit 14 of the indoor unit 2. The circuit 21 operates the compressor 3 in response to the operation signal _VD.
means for starting and stopping the operation signal _VD , means for releasing the holding operation of the self-holding circuit 22 when a certain period of time has elapsed after the operation signal VD was cut off, and a temperature difference signal circuit 15.
means for controlling the compressor drive frequency of the compressor control circuit 34 in response to the output V _T of the compressor control circuit 34, means for immediately shutting off the compressor control circuit 34 when an abnormal condition occurs and maintaining that state for a predetermined period of time, and further an abnormality display. A separate air conditioner characterized by comprising means for displaying an abnormal state on the circuit 18.