JPH03241258A - Air-conditioner - Google Patents

Abstract

PURPOSE:To prevent reduction in a defrosting capacity due to reduction in the quantity of heat of a heat accumulator by stopping an indoor fan when the temperature of a refrigerant on a high pressure side falls below a second temperature. CONSTITUTION:In a heating operation, when an outdoor heat exchanger 15 is frosted, a defrosting operation by heat accumulated in a heat accumulator is started and, at this time, whether the started defrosting operation is a stop defrosting operation is judged by stop defrosting operation judging means. When a result judged by the stop defrosting operation judging means is the stop defrosting operation, the number of revolutions of an indoor fan 25 is controlled by fan control means. That is, when the temperature of a refrigerant on a high pressure side detected by temperature detecting means 23 rises above a first prescribed value, the indoor fan 25 is rotated at a prescribed number of revolutions. On the other hand, when the temperature of the refrigerant on the high pressure side falls below a second prescribed temperature which is set lower than the first prescribed temperature, the indoor fan 25 is stopped. Thus, even in the stop defrosting operation, the optimum defrosting operation is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an air conditioner that can perform defrosting operation by stopping an indoor fan.

<Prior art> Conventionally, as shown in FIG. 3, there is an air conditioner in which a heat storage device 4 consisting of a heat storage heat exchanger 2 and a heat storage material 3 is disposed around the outer circumferential surface of a compressor 1. -542 publication). This air conditioner stores the heat radiated from the compressor in the heat storage material 3 during heating operation, and releases the heat stored in the heat storage material 3 during defrosting through the refrigerant passing through the storage heat exchanger 2. This defrosts the air while the heating is running.

In the air conditioner as described above, when an instruction is given to start a defrosting operation in a stopped state, the compressor 1 is operated with the indoor fan stopped and a defrosting operation begins. Hereinafter, such a defrosting operation will be referred to as a stopped defrosting operation.

<Problem to be addressed or solved> However, the heat storage capacity of the heat storage device 4 in the air conditioner is such that heating comfort is not impaired even if defrosting is performed while heating operation is being performed as described above. It is set.

Therefore, when the stopped defrosting operation is performed, the condensation temperature Tc of the indoor heat exchanger becomes abnormally high due to insufficient heat exchange in the indoor heat exchanger, and the peak cut control is activated. It's put away.

In this case, the frequency of the driving power source for the compressor 1 is lowered, so the amount of refrigerant circulated is reduced, and the defrosting ability is reduced. Then, when the de-KM operation continues and the condensation temperature Tc of the indoor heat exchanger reaches a predetermined temperature or higher, the operation of the compressor 1 is stopped to protect the compressor. If this continues, there is a problem that the islands accumulated in the heat storage material 3 are not transferred to the frosted part because the circulation of the refrigerant is stopped, and the frost remains unmelted.

Therefore, the purpose of the present invention is to provide an air conditioner that can optimally perform defrosting operation even when the defrosting operation is stopped.

<Means for Solving the Problems> In order to achieve this goal, the present invention is capable of performing peak cut control as illustrated in FIG. In an air conditioner that performs a defrosting operation, a stop defrosting operation determining means for determining whether or not the defrosting operation is a stop defrosting operation in which the indoor fan 25 is stopped to defrost the air, and a high pressure of the refrigerant. When the temperature detecting means 23 detects the temperature of the side and the stopped defrosting operation determining means determines that the defrosting operation about to be started is the stopped defrosting operation, the temperature detecting means 23 detects the temperature of the stopped defrosting operation. When the detected high-pressure side temperature of the refrigerant turns higher than the first temperature, which is higher than or lower than the peak cut control start temperature, the indoor fan 25 is rotated at a predetermined number of rotations, while the high-pressure side temperature of the refrigerant is When the temperature becomes much lower than the second temperature set lower than the first temperature, the indoor fan 25
It is characterized by comprising a fan control means for stopping the fan.

<Operation> During heating operation, when frost forms on the outdoor heat exchanger 15, a defrosting operation is started using the heat accumulated in the heat storage device. At this time, the stopped defrosting operation determining means determines whether the defrosting operation to be started is a stopped defrosting operation. and,
When the determination result sent to the stopped defrosting operation determining means is the stopped defrosting operation, the fan control means controls the rotation speed of the indoor fan as follows.

That is, when the temperature on the high pressure side of the refrigerant detected by the temperature detection means 23 becomes higher than the first predetermined temperature, the indoor fan 25 is rotated at a predetermined rotation speed. on the other hand,
When the temperature on the high pressure side of the refrigerant becomes lower than a second predetermined temperature that is set lower than the first predetermined temperature, the indoor fan 25 is stopped.

Therefore, since the first predetermined temperature is set to a temperature lower than the peak cut control start temperature, an abnormal increase in the condensing temperature during the stopped defrosting operation is prevented and the peak cut control is not performed.

Furthermore, if the second predetermined temperature is set to a temperature at which the indoor fan 25 is stopped in order to ensure the amount of heat storage, the minimum amount of defrosting heat during the stopped defrosting operation can be ensured. In other words, the defrosting operation is carried out optimally even during the stopped defrosting operation.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

According to the present invention, when defrosting operation is started in a stopped state, the number of revolutions of an indoor fan is controlled to optimally perform defrosting operation.

FIG. 1 is a refrigerant circuit diagram of an air conditioner according to the present invention. This refrigerant circuit includes a compressor 11. Four-way valve 12, indoor heat exchanger 13. Expansion valve +4. Outdoor heat exchanger 15. Four-way valve 12
and an accumulator 16 are connected in sequence. A heat storage device consisting of a heat storage heat exchanger 17 and a heat storage material is provided around the outer peripheral surface of the compressor 11. However, the heat storage material is omitted in FIG. 1. One end 17a of a refrigerant pipe provided in the storage heat exchanger 17 so as to spiral around the compressor 11 and the indoor heat exchanger! 3 and the expansion valve 14 are connected via a solenoid valve 21 and a bypass pipe. On the other hand, the other end 17b of the refrigerant pipe and the outdoor heat exchanger 15 and the expansion valve 14 are connected via a check valve 22 by a bypass pipe.

Above indoor heat exchanger! A thermistor 23 for detecting the condensation temperature Tc of the indoor heat exchanger 13 is installed near the indoor heat exchanger 13. The detection signal from this thermistor 23 is then input to the indoor microcomputer 24. On the other hand, a thermistor 27 is installed near the outdoor heat exchanger 15 to detect the evaporation temperature Te of the outdoor heat exchanger 15. Then, the detection signal from this thermistor 27 is manually input to the outdoor microcomputer 28.

The outdoor microcomputer 28 and the indoor microcomputer 24 execute the defrosting operation while exchanging information with each other.

That is, when the outdoor microcomputer 28 detects the start of the defrosting operation based on the detection signal from the thermistor 27, it opens the solenoid valve 21 and starts the defrosting operation. After that, when it is learned from the information from the indoor microcomputer 24 that the condensing temperature Tc of the indoor heat exchanger I3 has deviated from the peak cut control temperature, for example, the inverter 29 is controlled to change the drive power frequency of the compressor 11. lower. On the other hand, when the indoor microcomputer 24Let learns that the stop defrosting operation has started based on the information from the outdoor microcomputer 2B, the outdoor microcomputer 28
According to the information from the thermistor 23, a fan control signal is output to the fan motor 26 in accordance with the condensing temperature Tc of the indoor heat exchanger 13 based on the detection signal from the thermistor 23, thereby controlling the rotation speed of the indoor fan 25.

That is, the indoor microcomputer 24 constitutes a stop defrosting operation determination means and a fan control means.

In the air conditioner having the above configuration, the four-way valve 12 is switched as shown in FIG. 1 during heating operation.

Then, the high-temperature, high-pressure gas refrigerant discharged from the compressor 11 is condensed by the indoor heat exchanger (3), and the heat of condensation released at this time heats the room. The high-pressure branch refrigerant condensed by the indoor heat exchanger 13 is reduced in pressure by the expansion valve 14 and further evaporated by the outdoor heat exchanger 15 to become a low-pressure gas refrigerant and returned to the compressor 11. At that time,
Heat radiated from the compressor 11 is stored in the heat storage material.

In this state, the outdoor microcomputer 28
7 (for example, when the difference between the evaporation temperature Te of the outdoor heat exchanger 15 and the outdoor air temperature reaches a predetermined value), the defrosting operation must be started. The defrosting operation is started by opening the valve 2I. Then, as shown by the arrow in Figure 1, there will be an indoor heat exchanger! The high-pressure liquid refrigerant that has been condensed by 3 and heated the room with the heat of condensation passes through the solenoid valve 21, is depressurized, and reaches the regenerative heat exchanger 17. Then, heat exchange is performed in the thermal storage heat exchanger 17, and the heat accumulated in the heat storage material is recovered.

On the other hand, the high-temperature gas refrigerant that has undergone heat exchange in the regenerative heat exchanger 17 is supplied to the outdoor heat exchanger 15 via the check valve 22. The high-temperature gas refrigerant supplied to the outdoor heat exchanger 15 is condensed by the outdoor heat exchanger 15, and defrosting is performed by the heat of condensation generated at this time. The partially liquefied refrigerant returns to the compressor II via the four-way valve 12 and the accumulator 16.

Here, as described above, when the defrosting operation is performed when the operation is stopped (that is, when the stopped defrosting operation is performed), the indoor heat exchange is performed because the indoor fan 25 is stopped. Heat exchange in the vessel 13 is not performed sufficiently. Therefore, the condensation temperature Tc of the indoor heat exchanger 513 rises abnormally, the peak cut control is activated, and sufficient defrosting cannot be performed.

Therefore, the indoor microcomputer 24 controls the outdoor microcomputer 28.
The rotation of the indoor fan 25 is controlled based on the information from the indoor heat exchanger 13 to promote heat exchange to some extent and suppress the increase in the condensing temperature Tc.

FIG. 2 is a flowchart of the fan control operation performed by the indoor microcomputer 24 during the stopped defrosting operation. below,
Referring to FIG. 2, the procedure for controlling the fan during stopped defrosting operation will be explained.

The four-way valve 12 is set to the heating operation side and heating operation is started. At the same time, the fan control operation during stop defrosting operation starts.

In step S1, based on information from the outdoor microcomputer 28, it is determined whether or not the operation is in a stopped state.

As a result, if it is determined that the operation is in a stopped state, step S
Proceed to step 2, otherwise wait for the operation to stop.

In step S2, it is determined based on information from the outdoor microcomputer 28 whether or not the stopped defrosting operation is to be started. As a result, if it is determined that the stop defrosting operation is to be started, step S
Proceed to step 3, and if not, wait for the defrost operation to stop or start.

At that time, if the information from the outdoor microcomputer 28 is to stop the defrosting operation, the outdoor microcomputer 28 side opens the solenoid valve 21 and restarts the operation of the compressor 11 to start the defrosting operation. That's what I do.

In step S3, the indoor fan 25 is stopped, and the defrosting operation started by the outdoor microcomputer 28 as described above is set to a stopped defrosting operation. In this way, the stopped defrosting operation is started.

In step S4, the condensation temperature 1゛c of the indoor heat exchanger 13 is the outdoor heat exchange temperature when the outdoor microcomputer 28 enters peak cut operation? It is determined whether the temperature is higher than the temperature T c + which is set to be lower than the condensation temperature of 5I3. As a result, if the above-mentioned temperature Tc is higher, proceed to step S5,
Otherwise, step S5 is skipped.

In step S5, the rotation speed of the fan motor 26 is controlled by the fan control signal, and the rotation speed of the indoor fan 25 is set to a predetermined rotation speed N rpm.

Here, the rotation speed N is preferably a rotation speed of about 30 so that the user does not notice that the indoor fan 25 is rotating.
Orpm is preferred.

In step S6, it is determined based on information from the outdoor microcomputer 28 whether the defrosting operation has ended. the result,
If the defrosting operation has been completed, the fan control operation during defrosting operation is stopped. On the other hand, if the process has not ended, the process advances to step S7.

In step S7, it is determined whether the condensing temperature 1'c of the indoor heat exchanger 13 is lower than the temperature Tct.

As a result, if the temperature is lower than the temperature Tcy, the process proceeds to step S8; otherwise, the process returns to step S4.

Here, the temperature Tc is lower than the temperature Tc, and since the amount of heat accumulated in the heat storage device has decreased, the indoor fan 25 is stopped and set to a temperature that secures the amount of heat for defrosting. .

In step S8, the rotation speed of the fan motor 26 is controlled by the fan control signal to stop the indoor fan 25;
Return to step S4.

In this way, indoor heating is stopped and the amount of heat for defrosting is secured.

Then, as mentioned above, indoor heat exchange i! :If the condensation temperature Tc of i13 becomes higher than the temperature Tc +, the indoor fan 2
5 is set to a predetermined rotation speed N, while the temperature Tct
If the temperature becomes lower than that, the indoor fan 25 is stopped and the defrosting is completed. When it is detected that defrosting has ended based on information from the outdoor microcomputer 28, the fan control operation during the stopped defrosting operation is ended.

As described above, in this embodiment, when the outdoor microcomputer 28 detects that defrosting operation is necessary based on the detection signal from the thermistor 27, the outdoor microcomputer 28 controls the refrigerant flowing out from the indoor heat exchanger 13. The solenoid valve 21 for supplying heat to the outdoor heat exchanger 15 via the storage heat exchanger 17 is opened to start defrosting operation.

On the other hand, the indoor microcomputer 24 stops the indoor fan 25 when it determines that the defrosting operation to be started is a stopped defrosting operation based on the information from the outdoor microcomputer 28 . Thereafter, the condensing temperature Tc of the indoor heat exchanger 13 is monitored based on the detection signal from the thermistor 23. And the condensation temperature T
If the temperature is higher than ch<temperature Tc+, indoor fan 2
Set the rotation speed of No. 5 to the rotation speed N. Also, the condensation temperature Tc
When the temperature becomes lower than the temperature Tc, the indoor fan 25 is stopped.

Therefore, if the above-mentioned temperature Tc+ is set to a temperature lower than the peak cut control start temperature, the condensing temperature Tc becomes abnormally high and peak cut control is started during stopped defrosting operation, and as a result, the defrosting capacity This will prevent the frost from melting and remaining.

Also, temperature TC! If (<Te1) is set to a temperature at which the indoor fan 25 is stopped in order to secure the amount of heat for defrosting operation, the amount of energy for indoor heating can be maintained even if the amount of stored heat decreases during stopped defrosting operation. The defrosting ability will not decrease due to removal.

That is, according to this embodiment, the defrosting operation can be performed optimally even during the stopped defrosting operation.

In the above embodiment, a heating device is provided around the outer peripheral surface of the compressor II to accumulate the islands from the compressor 11. However, the present invention is not limited to this, and there is no problem in providing a heat storage device separately from the compressor 11.

The thermistor 23 in the above embodiment is the indoor heat exchanger 41
It is installed near No. 3 to detect the condensation temperature Tc. However, the invention is not limited thereto. In short, it is sufficient to detect the temperature on the high-pressure side of the refrigerant and detect the state before entering the peak cut control operation or the decrease in the amount of heat storage.

Although the above embodiment describes an air conditioner in which the drive power frequency of the compressor 11 can be controlled by the inverter 29, the present invention is not limited thereto. In this case, peak cut control includes, for example, rotation speed control of an outdoor unit fan.

The algorithm of the fan control operation during stopped defrosting operation in this invention is not limited to the above embodiment.

<Effects of the Invention> As is clearer, the air conditioner of this invention has the following effects:
The stop defrosting operation determining means includes a stopped defrosting operation determining means, a temperature detecting means, and a fan control means, and when the stopped defrosting operation determining means determines that the defrosting operation that is about to be started is a stopped defrosting operation, the fan controlling means (If the temperature on the high pressure side of the refrigerant detected by the temperature detection means becomes higher than the first temperature set lower than the peak cut control start temperature, the indoor fan is rotated at a predetermined rotation speed. It is possible to prevent peak cut control from occurring due to the temperature on the high pressure side of the refrigerant becoming abnormally high.Therefore, even if stop defrosting operation is started when the amount of heat stored in the heat storage device is sufficient, peak cut control is not performed. This prevents the defrosting ability from decreasing.

Further, the fan control means controls the high pressure 0111 of the refrigerant.
The indoor fan will be stopped if the temperature becomes lower than the second temperature, so if the second temperature is set to the temperature at which the indoor fan is stopped to ensure the amount of heat storage, the amount of heat in the heat storage device will be reduced. The defrosting ability will not decrease due to a decrease in the amount of water.

That is, according to the present invention, the defrosting operation can be carried out optimally even during the stopped defrosting operation.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the refrigerant circuit in the air conditioner of the present invention, Fig. 2 is a flowchart of fan control operation during stop defrosting operation, and Fig. 3 is an explanatory diagram of a compressor equipped with a heat storage device. It is. 11...Compressor, 13...Outdoor heat exchanger,
15... Outdoor heat exchanger, 17... Regenerative heat exchanger,
2! ...Solenoid valve, 23.27...Thermistor,
24.Indoor microcomputer, 25.Indoor fan, 26.Fan motor, 28.Outdoor microcomputer.

Claims (1)

[Claims] (1) In an air conditioner that can perform peak cut control and performs defrosting operation using the heat accumulated in the heat storage device, the defrosting operation is performed by stopping the indoor fan (25). A stop defrosting operation determining means for determining whether the defrosting operation is a stopped defrosting operation; a temperature detecting means (23) for detecting the temperature on the high pressure side of the refrigerant; When the stop defrosting operation determining means determines that the defrosting operation is in operation, the temperature on the high pressure side of the refrigerant detected by the temperature detecting means (23) becomes higher than a first temperature lower than the peak cut control start temperature. Indoor fan (25)
A fan that rotates the indoor fan (25) at a predetermined rotational speed, and stops the indoor fan (25) when the temperature on the high pressure side of the refrigerant becomes lower than a second temperature set lower than the first temperature. An air conditioner characterized by being equipped with a control means.