JPH01111169A - Blast controller for air conditioner with refrigerant heater - Google Patents

Abstract

PURPOSE: To employ a shading coil motor poor in low temperature starting characteristics by operating the shading coil motor simultaneously with refrigerant draining operation when heating operation is started and sustaining operation of a refrigerant heater if the r.p.m. of the motor is higher than a specified value upon ending refrigerant draining operation otherwise stopping operation of forcibly thereby ensuring the idling time of a fan. CONSTITUTION: A shading coil motor 4a begins to turn upon turning an operation switch 12 on. A rotation detecting circuit 4b operates during refrigerant draining operation but rotation is not detected because a controller 3 is not conducting. When a timer relay 13a times up, the controller 3 is conducted and rotation is detected by a microcomputer 18 through a pulse conversion circuit 17. If the r.p.m. is upper limit, a refrigerant heater driving relay coil 1b is not excited and operation of a refrigerant heater 1 is sustained. If the r.p.m. is lower limit, the relay coil 1b is excited to stop operation of the refrigerant heater 1 forcibly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for an air conditioner equipped with a refrigerant heater that increases the heating capacity at low outside temperatures. Features blower control.

Conventional technology Conventionally, the control content of an air conditioner equipped with a refrigerant heater is to use a compressor to remove the refrigerant from the outdoor heat exchanger (refrigerant removal operation) in order to ensure a sufficient amount of refrigerant circulation when heating starts. )
control was carried out for a certain period of time, after which the refrigerant heater was heated by combustion operation, and the refrigerant was circulated through the refrigerant cycle.

When this refrigerant heater is heated by combustion operation, a blower is essential to prevent incomplete combustion of the fuel (gas, oil, etc.), and therefore it is common to have a brake that constantly detects the operating status of the blower. was.

In addition, there are two ways to detect the operating status of the blower: one is to control it by the amount of air being blown, and the other is to detect the rotational speed of the motor.
These days, the latter (motor rotation detection) is overwhelmingly adopted due to its cost advantages.

3Beno' The control will be explained with reference to conventional examples shown in FIGS. 6 and 7.

Figure 6 shows a simplified internal diagram of the refrigerant heater.
Reference numeral 1 denotes a refrigerant heater, and its interior includes a combustion section 15, heat exchanger section piping 16, and an air blower 4. Inside the air blower 4, a condenser type induction motor 14 is built-in.

In the above configuration, during combustion, the operation of the blower 4 and the combustion part 1
5, the heat exchanger piping 16 is heated, and the refrigerant is heated and circulated through the refrigeration cycle. FIG. 7 shows the rotational speed detection control of the blower 4 at that time.

In the figure, the refrigerant is removed for a certain period of time after the start of operation, and then when the blower starts operating, the rotation speed is determined within T and the combustion operation is started. In other words, in conventional control, the blower starts rotating after refrigerant removal is completed, and if it reaches the rotation speed judgment value 1 within T (company), it starts the combustion operation, and if it is below the rotation speed judgment value even after T (9) or more has elapsed. For example, the refrigerant heater was forcibly stopped after determining that the blower was malfunctioning.

Problems to be Solved by the Invention In the conventional control as described above, if the motor that drives the blower is a conventional capacitor-type induction motor with a large starting torque, there will be no problem. When using a motor (no need),
This scheme creates problems.

In other words, if the starting torque is small, it will take a long time T (yf) to detect the rotational speed after a certain period of time from the start of combustion. If this time becomes longer, it will obviously take a longer time to start the combustion operation, which may lead to a decrease in heating start-up performance and a decrease in feeling.

Therefore, in this control, T(8) in FIG. 7 is not effective unless it is for a short period of time, and there have been problems such as the inability to use a shaded motor aimed at cost reduction.

In view of the above points, the present invention operates the blower of the refrigerant heater from the start of refrigerant extraction, detects the rotation speed at the same time as the combustion operation starts, and stops combustion if the rotation speed is below a certain rotation speed. A constant rotation speed device "-5" solves the above problem by allowing combustion to continue.

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the present invention uses a shaded type motor for the blower of the refrigerant heater, runs it from the start of refrigerant extraction, and increases the rotational speed at the same time as the combustion operation. The control unit is provided with a detection means and includes an operation/stop control means for the refrigerant heater.

Effect of the Invention With the above-described configuration, the present invention is able to perform the blowing operation of the refrigerant heater from the start of refrigerant removal, so that sufficient idling time can be ensured, and detection is performed while the rotation speed is stable, which is superior to the conventional technology. With the same control, a shaded motor with unstable starting torque is used, reducing costs.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a refrigeration cycle diagram in this embodiment, where 1 is a refrigerant heater, 2 is a compressor, 4 is a blower installed inside the refrigerant heater 1, and 61.-/ This blower 4 is a shaded type. The motor 4a constitutes a driving source. 3 is a control device that detects the rotation speed of the shaded motor 4a and controls the operation/stop of the refrigerant heater 1; 5 is a four-way valve; 6 is a two-way valve; 7 is a cooling pressure reducing device; 8 is a check valve,
9 indicates an outdoor heat exchanger, and 1o indicates an indoor heat exchanger. The compressor 2, the four-way valve 5, the indoor heat exchanger 10, the two-way valve 6, and the refrigerant heater 1 are connected in an annular manner.

Furthermore, in the figure, the refrigerant flows along a path shown by a solid line during cooling and a dotted line during heating. Note that since the gist of the present invention is the contents during the refrigerant heating operation during heating, the explanation will be limited to only the heating operation.

Next, the configuration of the sequence circuit diagram in this embodiment will be explained with reference to FIG. Note that the same functions as in FIG. 1 are indicated by the same numbers.

In the figure, 11 is a power supply, 12 is an operation switch, and 13 is a power supply.
is a timer relay, and 1a is a relay contact for driving the refrigerant heater.

Next, the operation in the configurations shown in FIGS. 1 and 2 will be explained.

Step 7: First, turn on the operation switch 12, and the compressor 2 and four-way valve 5
Then, the timer relay 13 and shaded motor 4a operate. At this time, the preset time of the timer relay 13 (
The operation is continued with the two-way valve 6 closed for only the refrigerant removal time.

Next, when the timer relay 13 times up, the timer relay contact 13a turns on, so the two-way valve 6 opens, and the refrigerant begins to circulate in the cycle indicated by the dotted line in the refrigeration cycle. At the same time, the control device 3 and the refrigerant heater 1
Since the refrigerant is also energized, the refrigerant heating operation is started.

The refrigerant heating operation during heating is performed by the following two operations.

Next, referring to FIG. 3, an electronic circuit diagram showing an example of a rotation detection means of a shaded motor which is a drive source of the blower 4 and an operation/stop means of the refrigerant heater 1 will be explained.

In the figure, inside the shaded motor 4a there is a rotation detection circuit 4b (the internal circuit is shown as a block diagram because it is well known) using a Hall element, and its signal line is connected to the pulse conversion circuit 17 of the control device 3. has been done. Its output is connected to a microcomputer (hereinafter referred to as microcomputer) 18.

Further, the side terminal of the microcomputer 18 is connected to the input side of an inverter element 19, and the output side of the inverter element 19 is connected to a 12V power source via a refrigerant heater driving relay coil 1b.

The operation of the configuration shown in FIG. 2, including a part of the sequence circuit shown in FIG. 2, will be explained.

First, when the operation switch 12 is turned on, the shaded motor 4a
starts rotating. In this state, since the refrigerant is being drained (because the timer relay 13 is counting), the rotation detection circuit 4b is operating, but since the control device 3 is not energized, rotation detection is not performed. However, the combustion operation starts (
Since the control device 13 is energized when the timer relay 138 times out (after the timer relay 138 times out), rotation detection is performed by the pulse conversion circuit 17.
The determination is made by the microcomputer 18 via . Regarding the rotation detection method of the microcomputer 18 at that time, in this embodiment, among various methods, input is made by counting the number of pulses in a fixed period of time. The detection means is determined by whether it is the lower limit or the lower limit. If this rotation speed is the upper limit, the refrigerant heater drive relay coil 1b is not excited and the refrigerant heater 1 continues to operate, and if the rotation speed is the lower limit,
The refrigerant heater driving relay coil 1b is energized to forcibly stop the refrigerant heater 1.

FIG. 4 is a distribution diagram of the number of revolutions of the shaded motor in this embodiment.

As is clear from the figure, the refrigerant is drained from the start of operation, and at the same time the shaded motor 4a also starts rotating. In other words, since the torque amplification time is provided during idling operation from the time when the refrigerant is being drained (approximately 90 seconds in the example),
Even in the case of the shaded motor 4a, which has a small starting torque, rotation detection is performed in a state in which the rotation speed reaches a predetermined rotation speed range by the time the refrigerant removal is completed.

FIG. 5 is a flowchart showing the control in this embodiment described above.

As described above, according to this embodiment, refrigerant removal starts 10'.
−.

Since the blower 4 can be operated from the start and the rotation speed can be detected at the same time as combustion starts with sufficient idling operation, it is possible to put it to practical use even with the shaded type motor 4a having a small starting torque, and the cost can be reduced.

In the above embodiment, the rotation detection means of the shaded motor 4a and the operation/stopping means of the refrigerant heater 1 are performed by a microcomputer, but the above control can also be performed by using discrete parts such as a capacitor, a resistor, and an IC. It goes without saying that it can be done.

Effects of the Invention As described above, according to the present invention, since the blower is operated at the same time as the start of refrigerant extraction, the idling time of the blower can be ensured before the start of combustion. The motor can now be used.

Therefore, in the case of the shaded type, it belongs to the inexpensive category of motors used for this type of application, and the motor itself is inexpensive compared to the capacitor type induction motor in particular, and there is no need for a capacitor. A significant cost reduction can be achieved. In addition, since the rotation is detected at the same time as combustion starts after refrigerant removal is completed, if the motor fails and the rotation is insufficient, the refrigerant heater will be stopped early, which is highly rated in terms of safety. It has various advantages.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle diagram of an air conditioner showing an embodiment of the present invention, Fig. 2 is a sequence circuit diagram of the air conditioner during heating, and Fig. 3 is an electronic circuit diagram showing an example of this embodiment. , FIG. 4 is an explanatory diagram showing the contents of the blower rotation detection control in the same embodiment, FIG. 5 is a flowchart diagram showing the control contents in the same embodiment, and FIG. 6 is a simplified internal diagram of the refrigerant heater in the conventional example. FIG. 7 is an explanatory diagram showing the contents of blower rotation detection control in a conventional example. 1... Refrigerant heater, 2... Compressor, 3...
Control device, 4... Blower, 4a... Shaded motor, 4b... Rotation detection circuit, 5... Four-way valve, 6... Two-way valve, 10...・・Indoor heat exchanger,
17... Pulse conversion circuit, 18... Microcomputer, 19... Inverter element.

Claims (1)

[Claims] A refrigeration cycle in which a compressor, a four-way valve, an indoor heat exchanger, a two-way valve, and a refrigerant heater are connected in an annular manner, a shaded motor for a blower drive source provided inside the refrigerant heater, and this shaded type a control unit comprising a detection means for detecting the rotation speed of the motor and a start/stop means for the refrigerant heater, and operates the shaded motor at the same time as the refrigerant draining operation at the start of the heating operation; If the number of rotations of the shaded type motor is above a predetermined number of rotations after the completion of the refrigerant extraction operation, the refrigerant heater is allowed to continue operating, and if the number of rotations of the shaded type motor is less than a predetermined number of rotations, the refrigerant heater is forced to stop. A blower control device for an air conditioner equipped with a refrigerant heater.