JPH025339Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an air conditioner, and particularly to an air conditioner that can defrost during heating.

[Technical background of the invention]

In an air conditioner that performs cooling and heating using a refrigeration cycle consisting of a compressor, an outdoor heat exchanger, an indoor heat exchanger, a four-way valve, etc., during heating, the outdoor heat exchanger absorbs heat during heat exchange, so it cools down. Frost is likely to adhere. When removing frost that has adhered in this way, conventional methods have used sensors, etc. to detect temperature changes on the indoor heat exchanger or outdoor heat exchanger to determine whether or not frost has adhered to the outdoor heat exchanger. do,
Defrosting was performed by switching the four-way valve. That is, by switching the four-way valve,
The refrigeration cycle is used for cooling, and the outdoor heat exchanger dissipates heat to melt and defrost surrounding frost.

[Problems with background technology]

In the case of using the above defrosting means, the temperature of the heat exchanger itself is detected, so when the temperature reaches the temperature at which defrosting is completed and the four-way valve is switched to the heating cycle again, the temperature of the heat exchanger itself is detected. Frost can be almost completely removed, but there is a drawback that frost and ice attached to the lower part of the heat exchanger cannot be completely defrosted, especially when the heat exchanger is operated continuously for a long time or when it snows. have.

[Purpose of invention]

The present invention was devised in view of the above-mentioned drawbacks, and an object of the present invention is to provide an air conditioner that can completely defrost the outside of the room under any conditions.

[Summary of the idea]

In order to achieve the above object, the air conditioner according to the present invention is an air conditioner that performs heating and cooling using a refrigeration cycle consisting of a compressor, an outdoor heat exchanger, an indoor heat exchanger, a four-way valve, etc. A pressure detection type sensor is placed near the bottom of the exchanger, and this sensor detects the pressure of frozen frost during heating and switches the four-way valve to defrost. It is also possible to completely defrost the air.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an air conditioner according to the present invention, in which an indoor heat exchanger 2 is provided on the indoor side surface of the main body casing 1, and an indoor fan 3 is provided inside the indoor heat exchanger 2. An outdoor heat exchanger 4 is provided on the inner outdoor side, and an outdoor fan 5 is provided inside the heat exchanger 4. Main body casing 1
A compressor 6 is disposed below near the indoor side, and an integrated air conditioner is shown.

Then, as shown in Fig. 2, the main body casing 1
A pressure detection sensor 8 is disposed in the gap between the bottom plate 7 and the lower end portion of the outdoor heat exchanger 4.

In this embodiment, when frost occurs on the outdoor heat exchanger 4 when the air conditioner is used for heating, the sensor 8 detects the pressure caused by the expansion when the frost freezes, and the four-way valve of the refrigeration cycle ( (not shown). As shown in FIG. 3, when the freezing pressure exceeds a certain value, a switch for changing the four-way valve is turned on and defrosting is started. As shown in FIG. 4, a pressure detection signal a is sent from a pressure detection type sensor 8 to a comparator 9, where it is compared with a reference pressure, and the deviation signal b is
is sent to the CPU (central processing unit) 10. The CPU 10 has functions such as calculations and timers in addition to defrosting control, and when the detected pressure exceeds the reference pressure, it sends a signal to the relay driver 11 and activates the relay driver 11 to activate the relay 12. Activate it and turn on the switch 13 that changes the four-way valve. That is, the comparator 9, CPU 10, relay driver 11, and relay 12 constitute a control device 14. When defrosting is completed and the pressure detected by the pressure sensor 8 falls below the reference pressure, the four-way valve is switched again via the CPU 10, relay driver 11, and relay 12, and the original heating cycle is resumed.

Therefore, in this embodiment, since the state of frost adhesion can be directly detected in the portion where frost adheres, complete defrosting can be performed in any operating state.

Note that a temperature sensor that directly measures the frost temperature can be used instead of the pressure sensor, but in this case, the sensor should be installed at the bottom of the outdoor heat exchanger, near the bottom plate of the main casing. This is desirable.

[Effect of idea]

As mentioned above, the air conditioner according to the present invention is
A pressure detection sensor is placed near the bottom of the outdoor heat exchanger, and the controller is equipped with a control device that detects the pressure of frozen frost during heating and switches the four-way valve to defrost the air. Since the frost adhesion state can be directly detected, complete defrosting can be performed even during long-term continuous operation or when it snows. Therefore, deformation of the main body casing or the outdoor heat exchanger due to frost can be prevented, and the service life can be improved.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention;
Fig. 2 is an enlarged view of the lower part of the outdoor heat exchanger in Fig. 1, Fig. 3 is a relationship diagram showing the response characteristics of the defrosting circuit when pressure is detected, and Fig. 4 is a diagram showing the response characteristics of the defrosting circuit when pressure is detected. FIG. 2 is a block diagram of the circuit leading to operation. 1... Body casing, 2... Indoor heat exchanger, 3... Indoor fan, 4... Outdoor heat exchanger,
5... Outdoor fan, 6... Compressor, 7... Bottom plate,
8...Pressure detection type sensor, 9...Comparator,
10...CPU, 11...Relay driver, 12
...Relay, 13...Four-way valve selector switch, a...
...detection signal, b...deviation signal, c...signal.

Claims (1)

[Scope of utility model registration request] In an air conditioner that performs heating and cooling using a refrigeration cycle consisting of a compressor, an outdoor heat exchanger, an indoor heat exchanger, a four-way valve, etc., a pressure detection sensor is placed near the bottom of the outdoor heat exchanger, and this An air conditioner characterized by comprising a control device that detects the pressure of frozen frost during heating using a pressure detection type sensor and controls a four-way valve to defrost.