JPS6134054B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in defrosting of a heat pump type air conditioner.

Defrosting of conventional heat pump air conditioners is generally a timer dayizer method, in which the temperature of the outdoor heat exchanger is sensed by a defrost thermometer after a certain period of time (for example, 50 minutes) has elapsed since heating has started, and the temperature is If the temperature is below the defrost temperature (e.g. -2.5℃), the defrost operation will start, and after a certain period of time (e.g. 10 minutes) or when the defrost thermostat reaches the defrost return temperature (e.g. 10℃), the defrost operation will start. Stop operation and start heating. and,
If the temperature is above the defrosting temperature, heating operation continues.

The defrosting method is carried out by driving the four-way switching valve in the heat pump cycle to switch from the heating cycle to the defrosting cycle (cooling cycle), and by stopping the blower of the indoor unit.

However, if this method is used, defrosting operation may be started immediately after the compressor is turned on, that is, when the indoor temperature has dropped and the room temperature is to be raised by heating.

If this happens, the indoor unit will be in a stopped state, causing the indoor temperature to drop further, making the user feel extremely cold, and causing a problem in the indoor environment.

Therefore, as shown in Japanese Utility Model Application Publication No. 55-140947, for example, defrosting operation is performed whenever the indoor temperature is higher than the set temperature, that is, the indoor temperature reaches a high temperature state that does not require heating. A system has been proposed that defrosts the air every time it is in use.

However, if you always defrost when there is no need for heating, the problem of the indoor temperature dropping suddenly will disappear, but
The four-way valve is switched frequently across the set temperature, and the cooling and heating cycles are switched.

When the four-way valve is switched, the high-pressure side and low-pressure side of the cycle are immediately balanced, resulting in gas noise, which is extremely unpleasant. Gas noise is generated, and the smaller the temperature differential in the room is, the more the gas noise generated by this switching becomes extremely inconvenient.

In addition, as mentioned above, this type of defrosting operation is performed by stopping the indoor unit, that is, by temporarily stopping heating, so in heat pump type air conditioners, it is important to avoid defrosting as much as possible when it is not necessary. In addition, the size of the heat exchanger and the capacity of the compressor were designed so that heating could be performed even in a state where frost had formed to some extent.

The present invention has been made in view of the above points, and it is possible to reduce the number of defrosting operations as much as possible, but prevent the indoor temperature from dropping significantly, the number of indoor temperature hunting increases, and the gas The purpose is to prevent noise from occurring frequently.

The present invention provides a device that performs heating and defrosting by switching a four-way switching valve, and includes: a timer for setting a defrosting time zone that sets the time for heating and the time for determining whether to perform defrosting; An indoor temperature sensing means for detecting temperature, a means for setting a temperature for determining whether heating is necessary, and a means for comparing the set temperature with the indoor temperature detected by the indoor temperature sensing means. a heat exchanger temperature sensing means for detecting the temperature of the outdoor heat exchanger; a means for setting a temperature at which the outdoor heat exchanger requires defrosting; and a means for setting a temperature at which the outdoor heat exchanger requires defrosting; means for comparing the detected temperature of the outdoor heat exchanger with the detected outdoor heat exchanger temperature; an AND means that outputs a signal when the temperature is above the temperature that does not require defrosting and below the temperature that requires defrosting of the outdoor heat exchanger; a four-way valve driving means for driving the valve and switching the cycle from the heating cycle to the defrosting cycle; In addition, when the temperature of the outdoor heat exchanger falls below the temperature that requires defrosting, defrosting can be performed when these three conditions are satisfied.

A detailed explanation will be given below using an example shown in the drawings.

A compressor 1 is connected to an indoor heat exchanger 3 via a four-way switching valve 2, and the indoor heat exchanger 3 has a parallel circuit of a heating pressure reducing device 4 and a cooling check valve 5, and a cooling pressure reducing device. 6 and a heating check valve 7 to an outdoor heat exchanger 8, and the outdoor heat exchanger 8 is connected to the compressor 1 via the four-way switching valve 2.

9 is a temperature-sensing means (for example, a thermistor) for detecting the indoor temperature for controlling the compressor 1, 10 is an indoor fan installed on the indoor heat exchanger 3 side, and 11 is installed on the outdoor heat exchanger 8 side. The outdoor fan 12 is a defrosting temperature sensing means (for example, a thermistor) provided in the outdoor heat exchanger 8.

During cooling operation, as shown by the solid line in Figure 1, the refrigerant from the compressor 1 passes through the four-way switching valve 2 and enters the outdoor heat exchanger 8, where it is condensed to become a high-temperature, high-pressure refrigerant liquid, which reduces the pressure for cooling. It flows into the indoor heat exchanger 3 through the device 6 and the cooling check valve 5. The refrigerant liquid vaporizes in the indoor heat exchanger 3 and absorbs heat there, and then returns to the compressor 1 through the four-way switching valve 2. The indoor temperature is determined by the compressor 1 by the temperature sensing means 9.
Adjusted by turning ON and OFF.

During heating operation, the compressor 1 is
Contrary to the above, the refrigerant passes through the four-way switching valve 2 and enters the indoor heat exchanger 3, where it is condensed to become a high-temperature, high-pressure refrigerant liquid, which is then passed through the heating pressure reducing device 4 and the heating check valve 7. The heat flows into the outdoor heat exchanger 12 through the heat exchanger 12 . The refrigerant liquid vaporizes in the outdoor heat exchanger 8 and absorbs heat there, and then returns to the compressor 1 through the four-way switching valve 2. Therefore, the condensed heat from the indoor heat exchanger 3 is sent into the room by driving the indoor fan 10, and the room is heated. The room temperature adjustment at this time is also performed by the temperature sensing means 9.

During the heating operation, the outside temperature is low and the outdoor heat exchanger 8 acts as an evaporator, so there is a drawback that frost adheres to the outdoor heat exchanger 8 and the heating capacity is reduced. Therefore, if frost forms, it is necessary to remove it.

In the above-mentioned defrosting, the present invention detects that the temperature-sensing means 9 for indoor temperature detection has reached a predetermined temperature or higher within a predetermined defrosting time period, and the defrosting device is provided on the outdoor heat exchanger 8 side. When the defrosting temperature sensing means 12 detects the defrosting start temperature, the defrosting circuit is operated, and the defrosting temperature sensing means 1
2 is characterized in that the defrosting operation is ended when the end of defrosting is detected or when a predetermined time has elapsed after the start of defrosting.

The electric circuits shown in FIGS. 2 and 3 will be explained below.

RY1 to RY4 are relays for controlling the indoor fan 10, outdoor fan 11, compressor 1, and four-way switching valve 2, and as shown in FIG. 2, relay RY1, indoor fan 10, relay RY2, compressor 1, and relay The series circuits of RY3 and four-way switching valve 2 are connected in parallel, and the compressor 1 has relay RY1.
A series circuit of the outdoor fan 11 and the outdoor fan 11 are connected in parallel.

The relays RY1 to RY4 are operated by an electronic circuit shown in FIG.

In Figure 3, 13 is a power supply section, 14 is a voltage drop transformer, 15 is a rectifier circuit, IC1 is a comparator for detecting room temperature, a variable resistor VR for setting the room temperature, and a thermistor for detecting room temperature. The signal from TH1 (temperature sensing means 9) is compared, and when the room temperature is above a predetermined temperature, the output signal becomes L, and when it is below the predetermined temperature, the output signal becomes H. IC2 is the first
As a timer, when the operation switch SW1 is closed, a signal from the auto-clear circuit consisting of capacitor _C1 and resistor _R1 enters the clear terminal CL, and starts counting after reaching the initial state. In the up state, the Q1 output changes from L to H and the Q2 output changes from H to L.
minutes).

IC4 is a flip-flop for starting defrosting.
The first timer IC2 counts up and reaches the defrosting time zone, and the comparator for detecting the room temperature
It is set when the output of IC1 changes from H level to L level, that is, when the room temperature becomes higher than a predetermined temperature, the Q output changes from L to H, and the output changes from H to L.

IC3 has a second controller for temporally controlling defrosting.
Flip-flop timer to start defrosting
Counting starts when IC4 is set and its Q output changes from H to L, and after a certain period of time (approximately 10 minutes), a time-up occurs and the Q output changes to L.
Changes from to H and clears IC4.

IC5 is a comparator for detecting the temperature of the outdoor heat exchanger 8, and when the thermistor TH2 (temperature sensing means 12 for defrosting) senses the defrosting start temperature, its output terminal is L, indicating that defrosting is necessary. When not doing so (including when defrosting ends), its output terminal becomes H and clears the defrosting start flip-flop IC4. Therefore, the above-mentioned flip-flop for starting defrosting
IC4 is the second timer IC3 that counts up for a certain period of time, or the thermistor.
It will be cleared when TH2 detects a temperature that does not require defrosting. Note that R1 to R16 are resistors, C1,
C2 is a capacitor, ZD is a Zener diode, D1 to D5 are diodes, OR1 to OR3 are OR gates, AND1 to AND5 are AND gates, TR
1 to TR5 are transistors.

Here, the heating operation and defrosting operation of the present invention will be explained. Now, when operation switch SW1 is "open", relays RY1, RY2, and RY3 are OFF.
Relay RY4 is also flip-flop IC4 for starting defrosting.
Since the Q output of is L, it is OFF. The relay RY
4 is OFF, the outdoor fan 11 is driven.

Therefore, when operation switch SW1 is closed during heating operation, relay RY1 is turned on and indoor fan 1 is turned on.
At the same time as the timer 0 starts operating, the clearing of the first timer IC2 is canceled and the first timer IC2 starts counting. At this time, the flip-flop for starting defrosting is
Since IC4 is still in the reset state, the Q output is L, the output is H, and relay RY3 is an AND gate.
It is turned on via AND4, and the four-way switching valve 2 is energized. On the other hand, relay RY4 is still OFF and outdoor fan 11 is being driven. When the room temperature is higher than the set temperature, the output of comparator IC1 is L, and relay RY2 is
If the room temperature remains OFF and the room temperature becomes lower than the set temperature, the output of the comparator IC1 becomes H, and the relay RY2 is turned ON via the OR gate OR1 and the AND gate AND3, and the compressor 1 is driven. This state is normal heating operation, and after a certain period of time (for example, 50
This continues until the first timer IC2 counts up in minutes).

Then, when the first timer IC2 counts up, the Q1 output becomes H, and the defrosting time period begins.
During this defrosting time period, when the room temperature reaches a predetermined temperature or higher and the output of the comparator IC1 changes from H to L, the flip-flop IC4 for starting defrosting is set.
Its Q output becomes H and the output becomes L. At this time, if the outdoor heat exchanger 8 is at a temperature that does not require defrosting, the output from the comparator IC5 is H, so the defrosting start flip-flop IC4 is cleared, and the above operation is repeated.

Now, when the defrosting start flip-flop IC4 is set and its Q output is H and the output is L, when the thermistor TH2 detects that the temperature of the outdoor heat exchanger 8 has reached the temperature required for defrosting, the output from the comparator IC5 is The level changes from H to L, and the flip-flop IC4 for starting defrosting is not cleared. Therefore,
Since the Q output of the defrosting start flip-flop IC4 is at H level, the relay RY2 is energized via the OR gate OR1 and the AND gate AND3, and the compressor 1 is continuously operated regardless of the H or L output of the comparator IC1. be driven. On the other hand, in response to the Q output of the flip-flop IC4 for starting defrosting, the relay RY4 is turned on, the outdoor fan 11 is stopped, and the first timer IC2 is passed through the OR gate OR2.
A clear signal is input to the clear terminal CL of the first timer IC2, and the first timer IC2 is cleared. Also, since the output of the flip-flop IC4 for starting defrosting changes from H to L, the AND gate AND4 is closed and the four-way switching valve RY is closed.
3 is turned off, a cooling circuit (defrosting circuit) is configured, and the second timer IC3 starts counting.

This is defrosting operation, and in this state, after a certain period of time (for example, 10 minutes), the second timer IC3 times up, its Q output becomes H, and the flip-flop IC4 for starting defrosting is reset.
Alternatively, the temperature of the outdoor heat exchanger 8 rises to a temperature that does not require defrosting, the output of the comparator IC5 becomes H, and the process continues until the defrosting start flip-flop IC4 is reset.

The first timer IC2 times up and the Q
1 output becomes H, if the room temperature does not rise to the set temperature and the output of comparator IC1 does not change from H to L, the Q1 output of IC2 will be Since the voltage changes from H to L, the flip-flop IC4 for starting defrosting is set, and the defrosting operation is performed in the same manner as above. Furthermore, if the output of IC1 never becomes H during the defrosting time period, the flip-flop IC4 for starting defrosting will not be set, and the first timer IC2 will not be set.
is cleared and returns to the point at which the operation started.

As described above, according to the present invention, within the defrosting judgment time set by the timer, the indoor temperature is above the temperature that does not require heating, and below the temperature at which the outdoor natural exchanger requires defrosting. When the temperature of the outdoor heat exchanger drops to a level that requires defrosting during the defrost judgment period, the four-way valve is activated to switch from the heating cycle to the defrosting cycle to perform defrosting. Heating continues until the indoor temperature rises to a temperature that does not require heating, so the room temperature does not drop significantly compared to simply detecting the outdoor heat exchanger temperature. , comfortable heating operation can be performed.

Moreover, even if the indoor temperature has reached a temperature that does not require heating, unless the temperature of the outdoor heat exchanger falls below the specified temperature, defrosting will not begin and heating will continue, so the outdoor heat exchanger will defrost the temperature. Defrosting is not performed when heating is not needed, and compared to a system that always defrosts when heating is not required based on the indoor temperature, the number of times defrosting is kept to the necessary minimum and the pressure when switching the four-way valve is reduced. It is possible to reduce the generation of balanced noise as much as possible, and to defrost efficiently.

In addition, basically, the timer setting distinguishes between the time for heating and the time for determining whether defrosting is necessary while heating continues, so defrosting operation that stops heating operation It is possible to provide comfortable heating by suppressing the amount of heat entering the room as much as possible.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the configuration of the air conditioner of the present invention;
The figure is the electric circuit diagram of the same air conditioner, and Figure 3 is the electrical circuit diagram of the air conditioner.
An electronic circuit diagram for explaining the operation of relays RY1 to RY4 shown in the figure is shown. 1: Compressor, 2: Four-way switching valve, 3: Indoor heat exchanger, 4, 6: Pressure reducing device, 8: Outdoor heat exchanger, 9:
Temperature-sensing means for detecting indoor temperature, 10: indoor fan,
11: Outdoor fan, 12: Temperature sensing means for defrosting, IC
2: 1st timer, IC3: 2nd timer, IC
4: Flip-flop for starting defrosting.

Claims (1)

[Scope of Claims] 1. In a device that performs heating and defrosting by switching a four-way switching valve, a defrosting time zone setting timer that sets the time for heating and the time for determining whether to perform defrosting. , an indoor temperature sensing means for detecting the indoor temperature, a means for setting a temperature for determining whether heating is necessary, and a means for setting the set temperature and the indoor temperature detected by the indoor temperature sensing means. a means for comparing; a heat exchanger temperature sensing means for detecting the temperature of the outdoor heat exchanger; a means for setting a temperature at which the outdoor heat exchanger requires defrosting; means for comparing the temperature that requires frosting with the detected outdoor heat exchanger temperature; an AND means for outputting a signal when the temperature is above a temperature that does not require heating and below a temperature that requires defrosting of the outdoor heat exchanger; A heat pump type air conditioner, comprising: a four-way valve driving means for switching the cycle from a heating cycle to a defrosting cycle by driving the four-way valve.