JPH05621B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention relates to the control of an air conditioner that can heat a room to be conditioned using a heat pump cycle and an electric heater for an auxiliary heat source. This invention relates to a control method that performs heating using an electric heater when the room temperature of a conditioned room falls below a predetermined value when the operation is stopped.

(b) Prior Art In general, there is a conventional control method for air conditioners as described in Japanese Patent Publication No. 47291/1983. This publication states that an air conditioner with a heat pump cycle is equipped with an electric heater as an auxiliary heat source, and when the outside air temperature drops and the heat pump cycle cannot reach its full capacity, the electric heater is energized to compensate for the lack of heating capacity. For example, when the air conditioner is stopped when you go out or at night, even if the room temperature in the room to be conditioned drops due to the drop in outside temperature, the air conditioner will continue to operate. In some cases, doors and windows were frozen, or water pipes were frozen, resulting in damage.

(c) Purpose of the Invention In view of such problems, the present invention provides a control method that automatically starts auxiliary heating of a conditioned room when the room temperature of the conditioned room drops even when the air conditioner is stopped. It provides:

(d) Structure of the invention The air conditioner method of the present invention includes a compressor, a condenser,
In an air conditioner that has a heat pump cycle configured by sequentially connecting a pressure reducing device and an evaporator in a ring with refrigerant piping, the condenser is equipped with an electric heater for an auxiliary heat source, and when the air conditioner stops operating, the room temperature of the conditioned room is maintained. When the temperature drops below a predetermined value, heating operation using the electric heater is performed, so that heating operation using the electric heater can be performed automatically when the room temperature in the conditioned room drops when the air conditioner is stopped. This is what I did.

(E) Embodiment Hereinafter, embodiments of the present invention will be explained based on FIGS. 1 to 8. First, FIG. 1 is a refrigerant circuit diagram showing an embodiment of the present invention. valve 2,
Indoor heat exchanger 3, liquid reservoir 4, pressure reducing device 5, 6,
A refrigeration cycle is constructed by connecting the outdoor heat exchangers 7 in an annular manner through refrigerant piping. Note that 8 is a check valve through which the refrigerant passes only when the refrigerant flows in the direction of the dotted line (during cooling operation). Further, 9 and 10 are first and second electric heaters, which are 2KW and 3KW, respectively. 11 is a blower (cross flow fan) for the indoor heat exchanger 3, and 12 is a blower (propeller fan) for the outdoor heat exchanger 7.

In this figure, when the four-way valve 2 is in the position shown, the refrigerant discharged from the compressor 1 flows in the direction of the solid arrow, and the indoor heat exchanger 3 becomes the condenser and the outdoor heat exchanger 7 becomes the evaporator. Heating operation is performed by acting on Furthermore, when the four-way valve 2 is switched to the opposite position to the illustrated position, the refrigerant discharged from the compressor 1 flows in the direction of the dotted arrow, and the indoor heat exchanger 3 becomes an evaporator and an evaporator, respectively.
The outdoor heat exchanger 7 acts as a condenser to perform cooling operation.

FIGS. 2 and 3 are electrical circuit diagrams used to control the operation of the refrigeration cycle shown in FIG. 1, and FIGS. 2 and 3 are connected by. Furthermore, the same components as in FIG. 1 are compressor 1, four-way valve 2, and first
The electric heater 9, the second electric heater 10, the indoor blower 11, and the outdoor blower 12 are given the same reference numerals. The wind speed of the blower 11 can be switched between high (H), medium (M), and low (L), and the wind speed of the blower 12 can be switched between high (H) and low (L).
The wind speed can be changed.

In FIGS. 2 and 3, 13 is a microprocessor, which operates together with the following peripheral circuits. The details of the operation of this microprocessor 13 will be described later. 14 is a power supply circuit, and rectifying element 1
5, smoothing capacitors 16, 17, Zener diode 18, power transistor 19, normally closed contact 2
0, a comparator 21 that resets the terminal (INIT) of the microprocessor 13 when the power is turned on, and a buffer 22 that supplies a constant voltage V _REF lower than V _ASS . Note that the terminal V _DD is a negative power supply terminal. 23 is a remote control panel, in which a manual switch 24 and a changeover switch 25 are provided separately from the main body of the air conditioner. The changeover switch 25 has terminals A, B, and C for switching contact pieces, and if terminal B is set as a neutral terminal, when the contact piece is switched to terminal A, the contact piece automatically returns to terminal B, and the contact piece is switched to terminal B. B,C
The time can be changed manually. Further, the manual switch 24 is for changing the temperature setting range, and the changeover switch 25 is for stopping the operation of the air conditioner, and they are separated by three wires. 26,
27 is a light emitting element, which lights up when the manual switch 24 and the changeover switch 25 are operated. 28,2
A relay 9 has a normally closed contact piece 20 and a normally open contact piece 30, respectively. 31 to 37 are batshua 38
It is a relay that operates by signals applied from terminals D6 to D12 of the microprocessor 13 via the terminals D6 to D12 of the microprocessor 13, and has normally open contacts 39, normally open contacts 40, normally open contacts 41, switching contacts 42, 43, switching contact piece 44,
45, a normally open contact piece 46, and a normally open contact piece 47. 48 is a rapid heating switch, and relay 3
4 and 37 are kept energized regardless of the output of the microprocessor 13. Furthermore, 49.5
0 is a diode for preventing malfunction.

51 to 53, 67 are microprocessors 13
Temperature sensors (such as negative characteristic thermistors) are connected between terminal A and terminals D3 to D5, D15, respectively, for detecting the room temperature inside the conditioned room, for detecting the temperature of the indoor heat exchanger 3, and for detecting the temperature outside the room. This is for detecting the temperature of the heat exchanger 7 and for detecting the outdoor temperature. 54 is a slide switch for temperature setting, and when there is an output at the terminal D1 of the microprocessor 13, the terminal K1 is
The setting values are read by scanning from K4 to K4. Note that 55 to 58 are diodes for preventing erroneous reading. A slide switch 59 sets the wind speed of the blower 11, and when there is an output at the terminal D0 of the microprocessor 13, the terminals K1 to K4 scan and read the set value. Note that 60 and 61 are diodes for preventing erroneous reading. Reference numerals 62 and 63 are operation/stop switches and heating/cooling operation selection switches, respectively. Note that 64 and 65 are diodes for preventing erroneous reading, and 66 is a manual switch. Also, the second
The states of the relay contacts shown in FIGS. 3 and 3 are all shown when the relay is not energized.

Next, Figures 4 and 6 show the microprocessor 13.
This is a flowchart diagram showing the operation, and is as follows. However, this flowchart shows only a part of the operation of the air conditioner, and does not show all the operations. First, when the cooling operation/heating operation selection switch 63 is set to heating operation, a "reset and start" process is performed. This is a start process when the power is turned on, and when the power is turned on, an output is given from the comparator 21 to the terminal INIT of the microprocessor 13.
The air conditioner is maintained in a stopped state by performing the reset process. Note that the relay 28 is energized and the normally closed contact 2
Even when 0 is opened, the air conditioner is reset in this way and the air conditioner is stopped. Next, the operation switch 62
When is pressed and operation starts, electric heater 9
(2KW) is applied to improve the start-up of heating operation.

Next, it is determined whether the switch 66 is ON or not, and when the switch 66 is ON and the air conditioner is not operating (stopped), the room temperature Tin in the conditioned room is "TinT ₀ (=3.5 degrees)". If so, energization of the electric heater 10 is started and energization of the electric heater 10 is maintained until the temperature rises to "TinT ₁ (=5.5 degrees)". still,
The values of T ₀ and T ₁ are not limited to these values, and may be arbitrarily set according to the surrounding conditions. At this time,
It is necessary to set an appropriate differential width as "T ₁ > T ₀ ".

Next, if the switch 66 is OFF or the air conditioner is in operation, read the room temperature set value T _S set by the slide switch 54. At this time, if the normally open contact piece 30 of the relay 29 is ON, the value of T _S is converted into "T _S = F (T _S )" using the conversion diagram in Fig. 5, and if the normally open contact piece 30 is OFF, the value of T _S is directly memorized, and this value T Compressor 1, based on _S
Controls the operation or energization of the electric heaters 9 and 10. In other words, the outside temperature Tout is “ToutT ₂ (=1.67
degree), the compressor 1 performs a heat pump operation and the electric heater 9 performs a heating operation.
If it is not "ToutT ₂ ", the compressor 1 is maintained in a stopped state and only the heating operation by the electric heaters 9 and 10 is performed. At this time, especially the electric heater 9
has a differential in which energization is started when the room temperature Tin is "TinT _S -1" and energization is cut off when the room temperature Tin reaches "TinT _S ". In addition, compressor 1
To prevent chattering due to ON-OFF,
A differential may be provided at the temperature at which this ON-OFF switching occurs.

In the above explanation, the compressor 1 and the electric heaters 9, 10 are actually operated or energized when the outputs of the terminals D8, D11, D12 of the microprocessor 13 become the ground level, and then the relays 33, 36,
37 is energized and its normally open contacts 41, 46, 4
This is done by closing 7.
Furthermore, compressor 1 and electric heaters 9 and 10 are turned on once.
Once in the ON state, the ON state is maintained until the OFF state is set.

Next, during cooling operation when the four-way valve 2 is switched in the opposite direction to the _state shown in FIG. Open contact piece 30 is ON
Then, using the conversion diagram in Figure 7, change the value of T _S to “T _S =
The value after converting to “G(T _S )” is also converted to normally open contact piece 30.
If is OFF, the value of T _S is directly stored, and based on this value T _S , the compressor 1 is operated to be in the ON state when “TinT _S ” and to be in the OFF state when “Tin< _TS ”. At this time, a differential is provided at the temperature at which compressor 1 switches between ON and OFF.
It is also possible to prevent ON-OFF chattering.

FIG. 3 is an electrical circuit diagram of the power section connected with the terminals shown in FIG.
2 is a current fuse or temperature fuse for protection, 73 is a main switch of the air conditioner, and 74 is an AC commercial power source. The other constituent elements are the same as those described above, and will therefore be omitted.

When the air conditioner configured as described above is operated, the air conditioner is operated in the state shown in FIG. 8 depending on the outside air temperature Tout and the indoor temperature Tin. If the outside temperature Tout is “ToutT ₂ ”, compressor 1 is turned off
Then, heating operation by the electric heaters 9 and 10 is performed. After this, leave “ToutT ₂ ” at room temperature.
rises and becomes “TinT _S ”, electric heaters 9 and 1
0 is in the OFF state. Thereafter, heating operation by the electric heaters 9 and 10 is performed until "Tout>T ₂ ". In this way, when the outside air temperature is low and sufficient heat pump operation cannot be maintained by the refrigeration cycle, the heat pump operation is stopped and the outside air temperature Tout
If Tout increases and becomes “Tout>T ₂ ”, the heating operation by heat pump operation can be sufficiently performed, and therefore the heating operation is switched to operation of the compressor 1 and heating operation by energizing the electric heater 9.

Also, when the air conditioner is not operating, the temperature Tin in the room to be conditioned decreases as the outside air temperature Tout decreases, and the temperature in the conditioned room becomes "TinT ₀ " and the switch 6 is turned off.
6 is in the ON state, the electric heater 10 is automatically energized and heating operation is performed until "TinT ₁ " is reached. This can prevent the water supply from freezing and the door from freezing due to a drop in temperature within the conditioned room.

Furthermore, when the manual switch 24 of the remote control panel 23, which is separated from the main body of the air conditioner, is operated from a remote location, the relay 29 is energized and the normally open contact piece 30 is closed, and at the same time the light emitting element 27 lights up. Normally open contact piece 3
0 is closed, the room temperature set value T _S is converted to "T _S =F (T _S )" based on the flowchart of FIG.
In other words, the setting range of the room temperature set value _{16T S}
By changing from "27" to "19T _S 24", heating operation can be performed without overheating or insufficient capacity.Also, by operating changeover switch 25, relay 2 can be switched on.
8 is energized to open the normally closed contact piece 20 and cut off the power supply to the microprocessor 13. When power is supplied again, the microprocessor 13 performs the "reset &reset" process based on the flowchart of FIG.
"Start" processing is performed. That is, the microprocessor 13 is reset and the air conditioner is brought to a halt.

The defrosting operation during the heating operation is generally performed by detecting the temperature of the outdoor heat exchanger 7 with a temperature sensor 53 and starting defrosting when the temperature change of the outdoor heat exchanger 7 reaches a certain condition. We use a method that
Similarly, to prevent cold air at the end of defrosting, a general method is used in which the blower 11 is stopped for a certain period of time based on the temperature of the indoor heat exchanger 3. Further, the blowers 11 and 12 are controlled based on the set value of the slide switch 59 or the states of the compressor 1 and electric heaters 9 and 10.

(F) Effects of the Invention As described above, the present invention provides an air conditioner having a heat pump cycle configured by sequentially connecting a compressor, a condenser, a pressure reducing device, and an evaporator in an annular manner through refrigerant piping. If the room temperature in the room to be conditioned falls below a predetermined value when the air conditioner is stopped, the electric heater will be used to warm or heat the air conditioner. Even if the room temperature of the conditioned room drops, heating or heating is automatically performed by the electric heater, and it is possible to prevent damage caused by freezing of doors and windows or freezing of water pipes caused by a drop in room temperature. Furthermore, if a switch is provided and a predetermined value is changed over, the lowest room temperature that meets the conditions of the room to be conditioned can be maintained and unnecessary operations can be avoided.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of an air conditioner using an embodiment of the present invention, Figure 2 is an electrical circuit diagram used to control the air conditioner shown in Figure 1, and Figure 3 is the same diagram as shown in Figure 1. Fig. 4 is a flowchart showing the operation of the microprocessor shown in Fig. 2 during heating operation, and Fig. 5 is an electrical circuit diagram used to control the air conditioner.
A conversion diagram showing the relationship between T _S and F (T _S ), Fig. 6 is a flowchart showing the operation of the microprocessor shown in Fig. 2 during cooling operation, and Fig. 7 shows the relationship between T _S and G
(T _S ), and FIG. 8 is an explanatory diagram showing the operation or energization state of the compressor, first and second electric heaters when the embodiment of the present invention is used. DESCRIPTION OF SYMBOLS 1... Compressor, 3... Indoor heat exchanger, 5, 6... Pressure reducing device, 7... Outdoor heat exchanger, 9... First electric heater, 10... Second electric heater.

Claims (1)

[Claims] 1. In an air conditioner that has a heat pump cycle configured by sequentially connecting a compressor, condenser, pressure reducing device, and evaporator in a ring with refrigerant piping, an electric heater for an auxiliary heat source is installed in the condenser, and the air conditioner is operated. 1. A control method for an air conditioner, characterized in that when the room temperature of the conditioned room falls below a predetermined value when the air conditioner is stopped, the room to be conditioned is warmed or heated by an electric heater.