JPH1183133A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent excess restarting time due to unnecessary slow start. SOLUTION: When performing an inspecting service, a service man turns OFF a circuit breaker 28, and inspects and repairs respective sections, and, at the time of finishing the inspection, a start switch 24a is normally set ON or OFF. First, a CPU 21 normally checks whether the switch 24 is ON or not at the initial time of starting after a controller power source is turned ON. In the case of ON, rotation of a motor M1 is accelerated to a rated rotational speed in about one minute. Meanwhile, if the switch 24a is OFF, the CPU 21 slowly starts the motor M1. That is, frequency data FE gradually raising to a rated value in about 30 min are sequentially outputted to an inverter 26. Thus, the rotational speed of the motor M1 is gradually accelerated to a rated speed in about 30 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which a restart time at the time of an inspection service or a power failure is reduced.

[0002]

2. Description of the Related Art As is well known, an outdoor unit of an air conditioner uses a compressor which compresses a refrigerant to produce a high-pressure gas. Oil is used for this. By the way, the compatibility between the refrigerant gas and the lubricating oil is high, and particularly when the temperature of the oil is low, a large amount of the solvent gas is dissolved in the oil. Then, when the solvent gas dissolves in the oil, the oil becomes thin and the lubrication function is reduced. Therefore, a crankcase heater is provided around the compressor, and when the air conditioner is turned off, this heater is energized to warm the oil, thereby lowering the oil temperature when not in use and dissolving the solvent gas into the oil. Is preventing that.

[0003] By the way, during the inspection service of the outdoor unit, the crankcase heater is also turned off to shut off the power supply.
It becomes FF, and the oil temperature drops. For this reason,
At the time of restarting after the inspection service is completed, it takes about 30 minutes of idling time to raise the oil temperature by the crankcase heater, and during this time, the rotation speed of the compressor motor is gradually increased to the rated rotation. (Hereinafter referred to as slow start). Also, at the time of the first installation, a slow start is similarly required.

[0004]

By the way, at the time of initial installation or replacement of the compressor, a slow start is unavoidable, but the conventional air conditioner requires a relatively short electric service check. Therefore, even when the refrigerant temperature is not so lowered, the slow start is performed, so that there is a disadvantage that it takes extra time to restart after the inspection service. Also, conventional air conditioners
Even when restarting after a power failure, a slow start is performed. Therefore, even when the power failure time is short, there is a disadvantage that the restart takes extra time.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an air conditioner that can prevent an unnecessary restart time from being taken by an unnecessary slow start. It is in.

[0006]

In order to solve the above-mentioned problems, the invention described in claim 1 is characterized in that a normal start function that is performed in a short time during normal operation and a time that is performed when restarting after power-off is performed. In an air conditioner having a long slow start function, a switch means for instructing a normal start or a slow start, and a control means for selecting and executing a normal start function / slow start function according to the switch means It is provided. The invention according to claim 2 provides an air conditioner having a normal start function that performs a short time during normal operation and a slow start function that performs a long time when restarting after turning off the power supply. And a control means for selecting and executing the normal start function / slow start function according to the measurement result of the measurement means.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing the configuration of the air conditioner according to the embodiment. In this figure, the right side of the dashed line indicates the outdoor unit, and the left side indicates the configuration of the indoor unit. In the outdoor unit, reference numerals 1 and 2 denote compressors, M1 and M2 denote compressor motors, and H1 and H2 denote crankcase heaters. 3 is an accumulator for separating gas and liquid, 4 is a four-way valve, 5 is a heat exchanger, 6 is an expansion valve, 7 is a check valve, and 8 is a controller for controlling each part of the outdoor unit. In the indoor unit, 10 is a heat exchanger, 11 is an electronic expansion valve, 12
Is a check valve, and 13 is a controller for controlling each part of the indoor unit.

In such a configuration, in the case of cooling, the refrigerant (gas) compressed by the compressors 1 and 2 and having a high pressure is sent to the heat exchanger 5 through the four-way valve 4, where it is heated to the outside. To liquefy. The refrigerant that has become a high-pressure liquid after passing through the heat exchanger 5 passes through the check valve 7 and enters the indoor unit. When entering the indoor unit, first, it is formed into a mist by passing through the electronic expansion valve 11, and then heat is absorbed and vaporized in the heat exchanger 10, and the vaporized refrigerant returns to the outdoor unit, and the four-way valve 4, the accumulator 3 Through the compressors 1, 2
Return to

In the case of heating, the refrigerant (gas) exiting the compressors 1 and 2 passes through the four-way valve 4 to the indoor unit heat exchanger 1.
0, where heat is released to the outside to liquefy. Next, the refrigerant (liquid) that has exited the heat exchanger 10 is guided to the expansion valve 6 via the check valve 12, passes through the expansion valve 6, is converted into a mist, and is sent to the heat exchanger 5. Then, the mist-shaped refrigerant absorbs external heat in the heat exchanger 5 and is vaporized, and the four-way valve 4, the accumulator 3
And returns to the compressors 1 and 2.

FIG. 1 is a block diagram showing the configuration of the controller 8 of the outdoor unit. In this figure, 21 is C
PU (Central Processing Unit), 22 is a ROM (Read Only Memory) in which a program used by the CPU 21 is stored, and 23 is a RAM (Random Access Memory) for temporarily storing data. An operation unit 24 is provided with a start / stop switch and other switches, and is usually provided with a start switch 24a. Reference numeral 25 denotes a communication circuit which converts parallel data supplied from the CPU 21 into serial data, outputs the serial data to the controller 13 of the indoor unit via a signal line S.
Is converted into parallel data and output to the bus line B of the CPU 21.

Reference numeral 26 denotes an inverter for driving the motor M1 of the compressor 1, which rectifies the three-phase AC voltage (commercial) into a DC voltage, and switches the DC voltage by a thyristor to generate a three-phase AC voltage again. And outputs it to the motor M1. The frequency of the AC output voltage of the inverter is determined based on the frequency data FD supplied from the CPU 21. R1 is an electromagnetic contactor, and inverter 2
6 is controlled to open and close by a NO (normally open) contact, and the crankcase heater H1 is set to NC.
(Normal close) ON / OFF control by contact. That is, when the electromagnetic contactor R1 is turned on,
When the heater H1 is turned off and the electromagnetic contactor R1 is turned off while the three-phase AC voltage is supplied to the inverter 26, the heater H1 is turned on while the three-phase AC voltage to the inverter 26 is cut off. Becomes Similarly, the electromagnetic contactor R2
Controls opening and closing of the input voltage of the compressor motor M2 by the NO contact, and controls ON / OFF of the crankcase heater H2 by the NC contact.

The interface 27 is provided with an electromagnetic contactor R1,
A circuit that controls ON / OFF of R2, decodes a command output from the CPU 21, and drives the electromagnetic contactors R1 and R2 according to the decoded result. Reference numeral 28 denotes a circuit breaker, which is always on, and is off only when an abnormality or an inspection service is performed.

Next, the operation of the controller 8 will be described. First, a normal operation will be described. When a start command is output from the controller 13 of the indoor unit to the signal line S, the communication circuit 25 (FIG. 1) converts the command into parallel data and outputs the parallel data to the CPU 21. Upon receiving this command, the CPU 21 sends the electromagnetic contactor R1 to the interface 27 first.
An instruction to set N is output. The interface 27 receives this command and drives the electromagnetic contactor R1. This allows
While the three-phase AC voltage is supplied to the inverter 26, the heater H1 is turned off. Next, the CPU 21 sequentially outputs the frequency data FD, which sequentially increases to the rated value in about one minute, to the inverter 26. Thereby, the inverter 26
The output frequency of the compressor motor M1 sequentially increases, and therefore, the rotation speed of the compressor motor M1 rises to the rated rotation speed in about one minute as shown in FIG.

Next, the CPU 21 operates the interface 2
7 to turn on the electromagnetic contactor R2. The interface 27 receives this command and drives the electromagnetic contactor R2. Thus, the three-phase AC voltage is supplied to the motor M2, while the heater H2 is turned off. Hereafter, C
The PU 21 controls ON / OFF of the electromagnetic contactor R2 according to the instruction of the controller 13 of the indoor unit, and controls the output frequency of the inverter 26 based on the frequency data FD. When a stop command is output from the controller 13 of the indoor unit, the CPU 21 sets the electromagnetic contactors R1 and R2 to O.
FF. Thereby, the motors M1 and M2 stop,
On the other hand, the heaters H1, H2 are turned on, and the compressors 1,
2. Prevent cooling of oil.

Next, the operation at the time of the inspection service will be described.
In this case, the serviceman turns off the circuit breaker 28 and checks and repairs each part. And check,
When the repair is completed, the normal start switch 24a is set based on the oil temperatures of the compressors 1 and 2. That is, in the inspection, there is no replacement of the compressors 1 and 2, and
If the inspection time is relatively short and the oil temperature has not dropped so much, the normal start switch 24a is turned on. On the other hand, if the inspection time is long or the compressors 1 and 2 have been replaced, the switch 24a is turned off. Then, the start of air conditioning is instructed from the indoor unit.

When the CPU 21 receives a start command from the controller 13 of the indoor unit, the CPU 21 determines that the normal start switch 24a is ON as shown in FIG. Check if not. If it is ON, the normal operation described above is performed. That is, the rotation of the motor M1 is increased to the rated rotation speed in about one minute, and then the motor M2 is started. On the other hand, when the normal start switch 24a is OFF, the CPU 21 performs a slow start of the motor M1. That is, the frequency data FD gradually rising to the rated value in about 30 minutes is sequentially output to the inverter 26. Thereby, as shown in FIG. 5, the rotation speed of the motor M1 gradually increases to the rated rotation speed in about 30 minutes. Then, when the rotational speed of the motor M1 reaches the rated rotational speed, the electromagnetic contactor M2 is turned on.

As described above, in the above embodiment, when restarting the inspection service, the service person can select the normal operation or the slow start operation. Thus, it is possible to prevent a disadvantage that the slow start is performed even though the slow start is unnecessary.

FIG. 6 is a block diagram showing another embodiment of the present invention. In this figure, portions corresponding to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. 2 is different from the circuit shown in FIG. 2 in that a backup power supply 30 is provided and a circuit breaker 28 is provided.
Power is supplied to the CPU 21 and the RAM 23 even when the power is turned off, and the R after passing through the circuit breaker 28 is supplied to the interface 27A.
Phase, S-phase power supply voltage is applied and the interface 27A
Is that the R-S phase voltage is rectified into a DC voltage, the voltage value is converted into digital data, and output to the CPU 21.

Next, the operation of the above circuit will be described. The normal operation of this circuit is the same as that of the circuit shown in FIG. 2, and the operation at the time of power failure is different. That is, the CPU 21 always reads the RS phase voltage via the interface 27A every time a predetermined time elapses, and checks whether the value is 0 or not. Then, when the RS phase voltage becomes 0, that is, in the case of a power failure, the power failure time is measured thereafter. Then, when the RS phase voltage returns to the normal voltage, as shown in FIG. 7, it is checked whether or not the power outage time is shorter than a predetermined time T (for example, 2 hours). If it is small, it is determined that the oil temperatures of the compressors 1 and 2 have not decreased, and normal operation is performed (see FIG. 3). On the other hand, when the power outage time is longer than the predetermined time T, it is determined that the oil temperatures of the compressors 1 and 2 have dropped, and the slow start operation (see FIG. 5) is performed. As described above, according to the above-described embodiment, the normal operation and the slow start operation can be automatically selected in the restart after the power failure. Thus, it is possible to prevent a disadvantage that the slow start is performed even though the slow start is unnecessary.

[0020]

As described above, according to the present invention, it is possible to obtain an effect that it is possible to prevent an unnecessary restart time from being caused by an unnecessary slow start.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a detailed configuration of a controller of an outdoor unit of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a refrigerant circuit of the air conditioner.

FIG. 3 is a graph showing a change in the rotation speed of a motor M1 at the time of a normal start in the air conditioner.

FIG. 4 is a flowchart for explaining the operation of the circuit shown in FIG. 1;

FIG. 5 is a graph showing a change in the number of revolutions of a motor M1 at the time of a slow start in the air conditioner.

FIG. 6 is a block diagram showing a configuration of a controller of an outdoor unit of an air conditioner according to another embodiment of the present invention.

FIG. 7 is a flowchart for explaining the operation of the circuit shown in FIG. 6;

[Explanation of symbols]

21 ... CPU, 22 ... ROM, 23 ... RAM, 24a ...
Normal start switch, 27A ... interface, 3
0: Backup power supply.

Claims (2)

[Claims] 1. An air conditioner having a normal start function that performs a short period of time during normal operation and a slow start function that performs a long period of time when restarting after the power is turned off indicates a normal start or a slow start. An air conditioner comprising: switch means; and control means for selecting and executing a normal start function / slow start function according to the switch means. 2. An air conditioner having a normal start function that performs a short time during normal operation and a slow start function that performs a long time when restarting after power is turned off. An air conditioner comprising: a control unit that selects and executes a normal start function / slow start function according to a measurement result of the measurement unit.