JPH0471129B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air-cooled heat pump type air conditioner.

FIG. 1 shows the refrigerant circuit of a conventional air-cooled heat pump type air conditioner. During cooling, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the discharge pipe 2, the four-way valve 3, and the pipe 19. It enters the outdoor air heat exchanger 16. In the outdoor air heat exchanger 16, the outdoor air blower 17 is operated to exchange heat between the outdoor air and the high-pressure gas refrigerant (here, heat is radiated) and condense the refrigerant into liquid refrigerant. The condensed liquid refrigerant passes through check valve 2
3, pipe 13, liquid side operation valve 5b, indoor side connection pipe 6
b. The air passes through the distributor 12 and enters the pressure reducer 11, where the air pressure is reduced, and then enters the indoor air heat exchanger 8. In the indoor air heat exchanger 8, the indoor air blower 9 is operated to exchange heat (here, heat absorption) between the indoor air and the reduced pressure liquid refrigerant, and evaporate the refrigerant into a gas refrigerant. Then, the evaporated gas refrigerant passes through the indoor connection pipe 6a, the gas side operation valve 5a, the pipe 4, the four-way valve 3, the pipe 20, and the accumulator 21, returns to the compressor 1 via the suction pipe 22, and returns to the compressor 1 again. It is compressed and repeats the same cycle.

During heating, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the discharge pipe 2, four-way valve 3, pipe 4, gas side operation valve 5a, and indoor connection pipe 6a to the indoor air heat exchanger 8. to go into. In the indoor air heat exchanger 8, the indoor air blower 9 is operated to exchange heat (radiate heat here) between the indoor air and the high-pressure gas refrigerant, and condense the refrigerant into liquid refrigerant. The condensed liquid refrigerant passes through the check valve 7, the indoor connection pipe 6b, the liquid side operation valve 5b, the pipe 13, and the distributor 14, and then enters the pressure reducer 15, where the pressure is reduced, and then the outdoor air heat exchanger 1
Enter 6. In the outdoor air heat exchanger 16, the outdoor air blower 17 is operated to exchange heat (in this case, absorb heat) between the outdoor air and the reduced pressure liquid refrigerant, and evaporate the refrigerant into a gas refrigerant. The evaporated gas refrigerant then returns to the compressor 1 via the pipe 19, four-way valve 3, pipe 20, accumulator 21, and suction pipe 22.
It is compressed again by the compressor 1, and the same cycle is repeated.

FIG. 2 shows the electrical circuit of the air conditioner, and in FIG. 2, CM is the motor for driving the compressor 1, FM ₀ is the motor for driving the outdoor blower 17, and 52
C is an electromagnetic contactor for CM, 52F ₀ is an electromagnetic contactor for FM ₀ , 20S is a four-way valve 3-switch electromagnetic contactor, TM is a timer motor, 23D is a thermistor contact for defrosting,
S ₁ is an operating switch, S ₂ is a cooling/heating changeover switch, 23 is a thermostat for controlling room temperature, 24 is a thermistor, and 29 is a defrosting device.

When frost forms on the outdoor air heat exchanger 16 during heating, in order to remove the frost, the pressure is reduced by the timer motor TM and the pressure reducer 15, which are configured as a cycle of a defrost-free time _T1 and a defrost-enabled time _T0 . The temperature of the refrigerant is detected by the thermistor 24, and when the temperature falls below the set value Th _L , the contact 23
When D becomes "open" and the refrigerant temperature exceeds the set value Th _H , contact 23D becomes "closed",
If the temperature of the refrigerant detected by the thermistor 24 is below Th _L within the defrost possible time T ₀ of the timer motor TM, the heating operation is switched to the cooling operation by opening the contact 23D and the defrost operation is performed. There is. Such defrost type air conditioners have the following drawbacks.

(1) Immediately after the heating starts, if the timer motor TM reaches the defrost possible time _T0 , perform "second defrost".

(2) If defrost operation is performed even though the amount of frost is very small, if defrost operation is ended and heating operation is resumed within the defrost possible time T ₀ of the timer motor TM, the refrigerant pressure in the circuit will suddenly fluctuate. transiently low pressure, i.e. the low pressure side of the refrigerant circuit (from the outlet of the pressure reducer to the inlet of the compressor)
As the pressure of the refrigerant in the circuit decreases, the refrigerant temperature at the thermistor mounting area decreases, so the defrosting time is reduced.
Within T ₀ , the temperature detected by the thermistor 24 becomes less than Th _L again, and the "secondary defrost" is performed again.

(3) During heating, high pressure control is performed on outdoor fan 1.
7, if the timer motor TM reaches the defrost possible time T ₀ during the stop and immediately after returning to operation, "Ni-Se Defrost"
Do this. These "Ni-Se Defrosts" occur when the thermistor 24 detects a drop in low pressure during a transient period due to sudden changes in refrigerant pressure, even though there is no frost on the outdoor air heat exchanger 16. This occurs due to

In other words, when the heating starts, the high and low pressures that are balanced suddenly develop a pressure difference between the high pressure side and the low pressure side, and the low pressure side almost overshoots as shown in Figure 7.
It drops to Pmin, then rises and stabilizes at P _L.
If Pmin then falls below the pressure value P23D for the "open" operating temperature of the thermistor 24, the thermistor 24 issues an "open" signal to the contact 23D.
In this case, no frosting phenomenon is observed due to the transient change. Note that the same applies when returning from defrost operation to heating operation.

High pressure control is a control method that is used when the outside temperature is high, such as in the middle seasons such as spring and autumn.
By starting and stopping the outdoor blower 17, the high pressure (in-circuit refrigerant pressure from the outlet of the compressor to the inlet of the pressure reducer) and low pressure are reduced, and the high pressure is controlled. In that case, as shown in Figure 8, the low pressure
When the temperature drops to Pmin, the thermistor 24 opens.
If the pressure drops below the operating temperature value P _23D , the thermistor 24 issues an "open" signal to the contact 23D.

If the low pressure drops below P _23D and the heating is running,
Although frost formation is observed on the outdoor heat exchanger 16,
At outside air temperatures that require high pressure control, frost does not form on the outdoor heat exchanger 16.

Note that the same situation as above occurs immediately after returning from high-pressure control to heating operation.

Examples of when to perform "Ni-Se Defrost" are: (1) Immediately after the heating starts (2) Immediately after the defrost returns (3) When the high pressure control is turned on to the outdoor air blower motor.
When performing ON-OFF, the outdoor fan
There are times when it is OFF and immediately after it is ON. The common points in these cases are (1) Immediately after the outdoor fan starts up, and (2) When the outdoor fan is turned off except during defrost.

Therefore, in the present invention, when performing high pressure control during heating by turning on and off the outdoor air blower motor, the ON and OFF signals are used, and in the ON and OFF signals of the outdoor air blower motor, (b) Do not output the defrost signal for the preset time after turning on.

(b) Do not output the defrost signal even when OFF other than during defrost operation.

By doing so, it is intended to prevent "necessary defrost".

The present invention will be specifically described below with reference to embodiments shown in FIG. 3 and below.

In Fig. 3, 63Hc is a control pressure switch attached to the refrigerant pipe that becomes high pressure during heating, 30 is a defrosting device, the details of which are shown in Fig. 4, and 50 is a power supply. detection device, 51
52 is an outdoor ventilation motor ON-OFF detection device.
53 is a temperature detection device, 53 is a temperature comparison and judgment circuit device,
54 is a timer circuit device, 55 is a defrosting discrimination circuit device, 56 is a relay circuit device, A, B, C, D, E
indicates the terminal positions to be connected in the circuit diagram shown in FIG.

The rest of the structure in FIG. 3 is the same as the conventional one shown in FIG. 2, and corresponding members are given the same reference numerals.

When heating operation is started, power is taken in from terminals C and E, and power supply detection device 50 sends a power ON signal for heating operation to defrost discrimination circuit device 55, and defrost discrimination circuit device 55 is activated. Temperature detection section 52
detects the temperature of the refrigerant reduced in pressure by the pressure reducer 15 during heating, and compares and determines the temperature with the temperature comparison judgment circuit device 5.
3 as a signal. Temperature comparison and determination circuit device 53
Then, it is determined whether the temperature has fallen below or above the set temperature Th _L to start defrosting, or whether it has reached the set temperature Th _H or higher to end defrosting during defrosting. The defrosting determination circuit device 55 determines whether the
send to The ON-OFF detection device 51 of the outdoor air blower motor FM ₀ detects the ON-OFF signal of the outdoor air blower motor FM ₀ taken in from terminals A and B.
It is sent to the defrost discrimination circuit device 55. Timer circuit device 5
4 is a device equipped with a timer that counts time based on a signal sent from the defrost discrimination circuit device 55, and when a certain set time elapses, it sends a signal indicating that “it has passed” to the defrost discrimination circuit device 55. . The relay circuit device 56 has a contact 23D,
When the defrost discrimination circuit device 55 sends an "open" signal, the contact 23D becomes "open" and the terminals C and D
This is a device that has the function of "opening" the gap. Then, when the "close" signal is sent again, the contact 23
D is "closed". Contact 2 of relay circuit device 56
When 3D is "open", defrost operation is performed.

In response to the signals and functions from these peripheral devices, the defrost discrimination circuit device 55 has the following functions. The defrosting discrimination circuit device 55 is the power supply detection device 5
0, ON-OFF input of the outdoor air blower motor FM ₀ , or status input of the outdoor air blower motor FM ₀ from the high speed/low speed switching detection device 51, temperature comparison/determination circuit device 53. This is a circuit that determines (determines) whether or not to send a defrost signal based on the temperature information input from the timer circuit 54 and the timer information input from the timer circuit 54. When the defrost signal is sent, the defrost signal is output to the relay circuit 56. have the effect of That is, as part 1, the ON-OFF detection device 51 of the outdoor air blower motor FM ₀
When an ON signal is issued from an OFF state,
In response to the ON signal, the defrost discrimination circuit device 55 causes the timer circuit device 54 to count the set time _T3 hours. During this time, the signal from the temperature comparison/judgment circuit device 53 is ignored. That is, until _T3 hours have elapsed, the defrost discrimination circuit device 55 does not operate the relay circuit 56.
does not send a signal to Then, after T ₃ hours have elapsed, if a signal indicating that the temperature is below the set temperature Th _L for starting defrosting is sent from the temperature comparison and determination circuit device 53 to the defrost determination circuit device 55, The defrosting discrimination circuit device 55 is a relay circuit device 56
Send a symbol to set contact 23D to "open", and
3D becomes "open".

Here, the outdoor air blower motor FM ₀ is ON−
There are three cases in which an ON signal is issued by the OFF detection device 51:

(1) When heating starts (2) When defrosting ends (3) When high pressure control returns when high pressure control during heating is performed by turning ON/OFF the outdoor air blower motor FM ₀ .

Second, turn on the outdoor air blower motor FM ₀ .
- When an OFF signal is output from the OFF detection device 51, the defrosting discrimination circuit device 55 detects the relay circuit device 5.
Check whether contact 23D is outputting an "open" signal to contact 6. When the contact 23D "open" signal is output to the relay circuit device 56, defrosting is in progress, and the time set by the timer circuit device 54 is
Defrosting is terminated when a signal is received whichever comes first: T ₄ hours have elapsed or the temperature has fallen below the set temperature Th _H of the temperature comparison/judgment circuit device 53.
In addition, when the contact 23D "open" signal is not output to the relay circuit device 56, the outdoor air blower motor
While the OFF signal from the FM ₀ ON-OFF detection device 51 continues, the defrost discrimination circuit device 55 does not output a signal to the relay circuit device 56 to open the contact 23D.

Here, the outdoor air blower motor FM ₀ is ON−
There are three cases in which an OFF signal is output from the OFF detection device 51:

(1) When the thermostat is OFF (2) When defrosting (3) When the high voltage is controlled by the outdoor air blower electric motor
At the start of high pressure control when performed by turning FM ₀ ON and OFF According to the present invention, during heating, high pressure control is performed by turning ON and OFF the outdoor air blower motor FM ₀ .
(1) Immediately after heating starts (2) Immediately after defrosting ends (3) During heating, when the outdoor fan motor FM ₀ is OFF during high pressure control, and when the outdoor fan motor FM ₀ is ON when returning to high pressure control Immediately after, "Ni Se Defrost" can be removed.

A second embodiment of the present invention is shown in FIG. 5, and in this embodiment, a control pressure switch 63Hc
Insert in series with the magnetic contactor 52F ₀ for FM ₀ , and connect the FM ₀
This is a case where high voltage is controlled by ON-OFF of the electromagnetic contactor _52F0 . In this case, the defrosting device 30 receives the ON-OFF signal of the FM ₀ electromagnetic contactor 52F ₀ from the terminals A and B.

A third embodiment of the present invention is shown in FIG. 6, and in this embodiment, an outdoor ventilation motor FM ₀
This is a case in which the high-speed and low-speed switching is possible, and high pressure control during heating is performed by switching between high-speed and low-speed.

In Figure 6, 52X ₀ is an electromagnetic contactor installed in series with the control pressure switch 63Hc.
ON-OFF: energized/de-energized.

FIG. 6 shows a non-excited state (before heating operation). During heating operation, when the pressure for high pressure control is not reached, the electromagnetic contactor 25X ₀ is excited and the outdoor fan motor FM ₀ rotates at high speed.
At that time, terminals A and B to the defrosting device 30 become ON signals. When the high pressure exceeds a certain set pressure, the contact of the control pressure switch 63Hc becomes "open", the electromagnetic contactor 52X ₀ becomes non-excited, and the outdoor fan motor FM ₀ slows down to perform high pressure control. At this time, terminals A and B to the defrosting device 30
becomes an OFF signal.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram of a conventional air-cooled heat pump type air conditioner, and FIG. 2 is an electric circuit diagram of the same. FIG. 3 is an electric circuit diagram showing one embodiment of the present invention, and FIG. 4 is a detailed circuit diagram of the same defrosting device. Fig. 5 is an electric circuit diagram showing a second embodiment of the present invention, Fig. 6 is an electric circuit diagram showing a third embodiment of the invention, and Figs. 7 and 8 are pressure changes during operation switching. FIG. Outdoor ventilation motor...18, FM ₀ , Outdoor ventilation motor ON-OFF or high-speed-low speed switching detection device...51, Outdoor ventilation motor high-speed-low speed switching device...52X ₀ , Timer circuit device... 54. Defrosting device...30.

Claims (1)

[Claims] 1. In an air-cooled heat pump type air conditioner that performs high pressure control during heating by turning the outdoor fan motor ON and OFF or switching between high and low speeds,
The defrost device is equipped with a relay circuit device that connects and disconnects the defrost operation circuit of the air conditioner, and a defrost device. - an outdoor air blower motor signal detection device that detects an OFF signal or a high-speed/low-speed switching signal, and a temperature comparison/judgment device that outputs a judgment result by comparing a detected value of refrigerant temperature with a set temperature for starting or ending defrosting. , power ON-OFF signal from the power supply detection device, ON- of the outdoor ventilation motor from the outdoor ventilation motor signal detection device
The OFF signal or high-speed/low-speed switching signal and the comparison judgment result between the set temperature for starting or ending defrosting from the temperature comparison judgment device and the detected value of the refrigerant temperature are input, and based on these input signals, defrost is sent to the relay circuit device. An air-cooled heat pump air conditioner comprising a defrost discrimination circuit device that determines whether a signal is necessary.