JPS5832296B2 - Split type heat pump air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a split type heat pump near conditioner, and particularly to a near conditioner that can detect freezing of an outdoor heat exchanger indoors.

As a near conditioner, heat pump types have come to be widely used for both heating and cooling, but split types have a compressor and a heat exchanger for evaporation during heating (for condensation during cooling) separated and installed outside. θ) In a heat pump near conditioner, when defrosting the outdoor heat exchanger during heating operation, in conventional equipment, a temperature sensor is attached to the outdoor heat exchanger, and the output is used as a defrost signal to operate a timer. The defrosting operation was performed in combination.

However, since the main body of the electronic control equipment that performs operation, ventilation, control, etc. is usually installed indoors, if the temperature sensor is installed on the outdoor heat exchanger side as described above,
This has the disadvantage of increasing the amount of connection wiring between indoor and outdoor units, which complicates installation work.

The present invention has been made to eliminate the above-mentioned disadvantages of conventional devices.

That is, an object of the present invention is to provide a split type heat pump near conditioner that detects freezing of an outdoor heat exchanger and generates a defrost signal without directly measuring the temperature of the outdoor heat exchanger.

The present invention will now be described in detail with reference to the illustrated embodiments.

In FIG. 1, an indoor unit 1 includes an indoor heat exchanger 3, an air filter 4, a fan 5, and an electronic circuit described below in a casing 2.

An indoor temperature sensor 6 that detects the temperature of the indoor air sucked into the indoor heat exchanger 3 is arranged in front of the indoor heat exchanger 3.
Further, an indoor heat exchanger temperature sensor I is installed inside the indoor heat exchanger 3 to detect its temperature.

As shown in FIG. 2, the indoor unit 1 configured as described above is connected to the compressor 10 via the four-way valve 9 together with the outdoor unit 8.
2.13 indicates an expansion valve.

FIG. 3 shows the electric control circuit of the split type heat-operated knob air conditioner constructed as described above.

In the figure, a first contact RDI of a defrosting relay RD and an indoor fan motor 1a are connected via an operation switch 14 between both ends of the power supply plug.

Further, the heating terminal of the operation switch 14 is led to the four-way valve coil 9a through the second contact RD2 of the defrosting relay RD.

Further, the operation switch o) the cooling terminal and the heating terminal are connected to the seventh breather 10 through the switching contact RT1 of the room thermo relay RT, and the third
It is connected to the outdoor unit 0 fan motor 8a through a contact point Rp3.

Note that RC is a thermorelay for the indoor fan motor 1a that is turned on and off by the indoor heat exchanger temperature sensor 7, and the control circuit in FIG. 4 is omitted.

FIG. 4 shows an example of an indoor electronic circuit in the apparatus of the present invention.

In the same figure, a room temperature sensor 6 consisting of a resistor r1p thermistor, etc., a variable resistor r2, and resistors r3+r4 are connected to the DC 12V0 power source.

The room temperature sensor 6 is connected to the differential input terminal of the DC amplifier AT.
The midpoint voltage between T and resistor rl and the midpoint voltage between resistors r3 and r4 are input, and a room thermorelay RT and a protection diode DT are attached to the output side.

On the other hand, the two input terminals of the second DC amplifier AD, in which the defrosting relay R1) and the protection diode DD are connected between the output terminal and the DC power supply, are connected to the variable resistor r and the midpoint voltage of the resistor r6. Room temperature sensor 6D and indoor heat exchanger temperature sensor 7
The midpoint voltage of is applied.

In the apparatus of the present invention configured as described above, when the apparatus is operated for heating, the flow of the refrigerant is as shown by the arrow in FIG. 2, and the indoor heat exchanger radiates heat and the outdoor heat exchanger 8 absorbs heat. .

In FIG. 3, the knob (not shown) of the operation switch 14 is in the heating Q) position, and the room thermo relay RT
The switching contact RT1 connects the heating terminal and the compressor 10 and drives the compressor 10.

Also, since the defrosting relay RD does not operate at this time, each contact of the first contact RDI + second contact RD2 + third contact RD3 is closed and the indoor fan motor 13. Four-way valve coil 9
3. Outdoor unit 0 fan motor 8a is energized and normally 0
) Heating operation is performed.

Then, when the indoor temperature rises to the set temperature of the room temperature sensor 6T, switch the switching contact RTt of the room thermorelay RT to the cooling terminal to stop the compressor 10 and fan motor 8a, and when the indoor temperature falls below the set temperature of the room temperature sensor 6T. The so-called compressor 10o which performs heating operation again performs controlled operation by turning on and off.

If the heating operation continues in this manner, the air heat source becomes insufficient when the outside air temperature is low, and the outdoor heat exchanger freezes.

When the amount of heat absorbed from the outside air decreases due to this freezing, the temperature of the indoor heat exchanger naturally decreases, and the heating capacity decreases.

This heating capacity can be approximately expressed by the product of the difference between the indoor heat exchanger temperature and the intake air temperature and the indoor air volume, so these three signals (in some cases, two signals excluding the air volume signal) are detected. By making this determination, it is possible to indirectly know whether the outdoor heat exchanger has frozen.

Therefore, as shown in Figure 4, the difference in resistance change between the room temperature sensor 6D and the indoor heat exchanger temperature sensor 7o)
When the width increases to a certain value, the defrosting relay RD is activated and turns off the four-way valve coil 9a, thereby switching the four-way valve 9 in FIG. 2 to perform a cooling cycle operation and cooling the outdoor heat exchanger. Defrosting can be carried out by introducing hot gas from a compressor 10 into 8.

In order to return to heating operation after defrosting operation has started, well-known means such as combining a timer may be used.

In this way, freezing can be detected without providing a temperature sensor on the outdoor heat exchanger side, and the necessary defrost signal can be obtained.

In addition, in FIGS. 3 and 4, the room temperature sensor 6T
The controller performs a so-called control operation in which the room thermorelay RT is turned on and off to turn on and off the compressor 10 by detecting the height of the indoor temperature during both cooling and heating.

In addition, the indoor heat exchanger temperature sensor 1 controls the indoor fan motor 1a so that the fan 5 does not start operating until the temperature of the indoor heat exchanger 3 becomes sufficiently high at the time of starting the heating operation.
O) Turn off thermorelay Re to prevent cold draft.

As described above, the present invention does not directly measure the temperature of the outdoor heat exchanger. It can be directly connected to electronic control equipment installed indoors that controls operation, ventilation, etc., simplifying the connection wiring between indoor and outdoor units.

Moreover, since the defrosting operation is started based on the difference between the indoor heat exchanger temperature and the room temperature, even if the room temperature changes due to opening and closing of the room door, the indoor heat exchanger temperature will change accordingly. Since it follows the change, it is difficult for the temperature difference to fluctuate and the start of defrosting can be detected accurately.

In addition, there is no need for a dedicated temperature sensor to detect the start of defrosting, and for example, when the indoor heat exchanger temperature does not reach a high enough temperature during heating, the indoor fan is not operated to prevent cold drafts. The heat exchanger temperature sensor and the room temperature sensor in the existing device may also be used to detect the start of defrosting in order to detect the indoor temperature and turn the compressor on and off during both cooling and heating operations.

[Brief explanation of the drawing]

Figure 1 is a schematic sectional view showing an example of an indoor unit according to the present invention, and Figure 2 is a heat pump near conditioner Q.
FIG. 3 is a circuit diagram showing an example of an electric control circuit according to the present invention, and FIG. 4 is a circuit diagram showing an example of an electronic circuit Q of an indoor unit according to the present invention. 1...Indoor unit, 3...Indoor heat exchanger, 511961. Fan, 6, 61, 6D...
...Indoor temperature sensor I...Indoor heat exchanger temperature sensor, 8...Indoor outdoor unit, 9...Four-way valve, 9a...Four-way valve coil, 10...・・・・・・
Compressor 14... River/operation switch, RD...
...Defrost relay R1) + , RD2 + RD3
...Defrost relay contact, Rr...Room thermorelay Rrl...Room thermorelay contact.

Claims (1)

[Claims] 1 1st c to detect indoor heat exchanger temperature of indoor unit
)) A temperature sensor, a second temperature sensor that detects the temperature of the air sucked into the indoor heat exchanger, and a temperature sensor that detects the temperature of the indoor heat exchanger based on the outputs of the first and second temperature sensors. A split type equipped with an indoor control device that performs heating operation when the temperature of the air being sucked in is higher than a predetermined value, and activates a defrosting relay circuit to start defrosting operation when the temperature of the air is higher than a predetermined value. Heat pump near conditioner.