JPH08178447A - Multi-room split type air conditioner - Google Patents

Abstract

PURPOSE: To recover the refrigerant of a stopping unit by assuming that the refrigerant stagnates in a stopping indoor unit when an outdoor unit is continued for a predetermined time to heat, opening the refrigerant flow control valve of the indoor unit, and previously setting the operating capacity of a capacity variable compressor in response to the number of the stopping indoor units. CONSTITUTION: When an outdoor unit SG having a capacity variable compressor 1B and a plurality of indoor units U1, U2, U2 respectively having refrigerant flow control valves 10 are provided and the unit SG continuously heats for a predetermined time, it is assumed that any of the units U1, U2, U3 stagnates refrigerant during stopping. The valves 10A to 10C of the units U1 to U3 are released, and the capacity of the compressor 1B is raised by preset capacity in response to the number of the units U1, U2, U3. Thus, the recovery of the refrigerant from any of the units U1, U2, U3 during stopping can be efficiently conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-system air conditioner comprising an outdoor unit having a plurality of compressors including a variable capacity compressor and a plurality of indoor units each having a refrigerant flow rate adjusting valve.

[0002]

2. Description of the Related Art In a multi-system air conditioner having the above structure, when an outdoor unit is in a heating operation and there is an indoor unit that is suspended because a detected room temperature approaches a set temperature, There is a phenomenon (also referred to as "liquid stagnation") that refrigerant accumulates in a heat exchanger of an indoor unit that has been stopped. Refrigerant stagnation in the heat exchanger of the indoor unit that is not operating is due to system operation.
In some cases, this causes a shortage of the refrigerant, resulting in a lack of capacity in the operating indoor unit, and in the worst case, the low pressure abnormality of the refrigerant causes the protection device to operate and stop the entire system. In order to avoid such an undesired situation, the refrigerant flow rate adjusting valve of the stopped indoor unit is opened and closed for a certain period of time for a certain period of time, so that the heat exchanger of the indoor unit in which the operation is stopped is stopped. A refrigerant recovery operation is performed to recover the refrigerant that has accumulated in the.

Furthermore, when a part of the indoor units is stopped during the heating operation, the piping and heat exchanger of the stopped indoor unit are warmed by the heat from the operating indoor unit, The above-described refrigerant recovery operation also causes a phenomenon in which heat remains in the stopped indoor unit. For example, if the indoor unit that was stopped was in cooling operation before it stopped, moisture adhered to the heat exchanger in a dew condensation state, and other indoor units will continue to perform heating operation in that state. If this is done, the temperature of the heat exchanger of the stopped indoor unit rises, moisture due to dew condensation begins to evaporate, and dew condensation occurs at a portion of the indoor unit such as a metal plate having a temperature lower than that of the heat exchanger. As this condensation grows, it drips into drops of water. The situation where a water drop falls from an indoor unit into a room is often perceived by the user as a water leakage failure of the indoor unit. In order to avoid such a situation where water droplets drop due to dew condensation, insulate the indoor unit in advance where dew condensation may occur, and place a drain tray or pan at the location where water droplets fall out. Was.

[0004]

First of all, first of all, the situation in which the refrigerant stays in the indoor unit when the operation is stopped,
That is, it is a case of performing a refrigerant recovery operation to avoid liquid stagnation, but in this case, a refrigerant recovery operation such as opening and closing the refrigerant flow rate adjusting valve of the stopped indoor unit without increasing the rotation speed of the compressor is performed. If this is done, it will be difficult for the refrigerant to flow to the operating indoor unit, and especially if there is a relationship of "heat exchanger capacity of stop unit" ≥ "heat exchanger capacity during operation", the refrigerant recovery operation Each time there is a tendency for the capacity of the operating unit to decline. Further, when the refrigerant flow rate control valve is not controlled to be intermittently opened and closed, but only to control the operation time, due to the operating conditions, the refrigerant cannot be collected in time and the system, i.e., the operating unit, causes a shortage of the refrigerant, that is, a shortage of the capacity, As described above, in the worst case, the protection device operates due to the decrease in the refrigerant pressure, and the system is stopped.

Next, as a countermeasure against the drop of water droplets, a method of attaching a heat insulating material or disposing a drain tray or a tray is available. However, even with such a countermeasure, dew condensation on the indoor blower body cannot be prevented. Condensation also forms on the heat insulating material in places with high humidity. Further, by further providing a heat insulating material, a drain tray, and a tray, the cost of the indoor unit will be increased. Furthermore, even if dew condensation can be prevented by attaching a heat insulating material or the like, it is not possible to prevent the atmosphere inside the indoor unit from becoming hot and humid and causing mold and strange odor.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a multi-system air conditioner capable of efficiently recovering a refrigerant from a stopped unit without lowering the capacity of the operating unit. To aim.

A further object of the present invention is to provide a multi-system air conditioner capable of removing a high temperature and high humidity atmosphere in an indoor unit that is stopped to prevent dew condensation.

[0008]

In order to achieve the above object, the invention of claim 1 includes: an outdoor unit having a plurality of compressors including a variable capacity compressor; and a plurality of units each having a refrigerant flow rate adjusting valve. In a multi-system air conditioner including an indoor unit, when a part of the indoor units is stopped during operation in the heating operation mode or is temporarily stopped by indoor thermo-off, the first The first detecting means, the second detecting means for detecting the outdoor unit when the outdoor unit continuously performs the heating operation for the first set time, and the first refrigerant for collecting the refrigerant accumulated in the stopped indoor unit, And opening the refrigerant flow rate adjusting valve of the stopped indoor unit in response to the output detection signal of the second detection means,
And a control means for performing a heating refrigerant recovery operation for increasing the operation capacity of the variable capacity compressor set in advance according to the number of stopped indoor units.

Further, in the invention of claim 2, in the multi-system air conditioner according to claim 1, the control means sets the capacity variable compressor to a preset capacity according to the capacity and the number of the indoor units which are stopped. It is characterized by raising.

According to a third aspect of the present invention, in the multi-system air conditioner according to the first aspect, the discharge temperature sensor for detecting the discharge pipe temperature of each compressor and the detected temperature value of the discharge temperature sensor are set to the first setting. A third detection means for outputting a detection signal when the temperature is kept above the temperature for a second set time shorter than the first set time, and the control means responds to the output detection signal of the third detection means. Perform a heating refrigerant recovery operation.

According to a fourth aspect of the present invention, in the multi-system air conditioner according to the first aspect, a suction pressure sensor for detecting a suction side pressure of the compressor, and a suction temperature sensor for detecting a suction pipe temperature of the compressor. Detected when the suction pressure sensor detected pressure value is below the first pressure set value and the suction temperature sensor detected temperature value is above the set temperature for a third set time shorter than the first set time. A fourth detecting means for outputting a signal is further provided, and the control means performs the refrigerant recovery operation in response to the output detection signal of the fourth detecting means.

According to a fifth aspect of the present invention, in the multi-system air conditioner according to the first aspect, the second temperature detected by the discharge temperature sensor is lower than the first set temperature while the compressor is operating in a low capacity region. Further includes a fifth detection means for outputting a detection signal when a state of being equal to or higher than the set temperature of is continued for a fourth set time shorter than the first set time, and responding to the output detection signal of the fifth detection means. The control means carries out the heating refrigerant recovery operation.

According to a sixth aspect of the present invention, in the multi-system air conditioner according to the first aspect, there is further provided a sixth detection means for detecting the switching to the heating operation after the completion of defrosting and outputting a detection signal. It is characterized in that the control means performs the heating refrigerant recovery operation in response to the output detection signal of the sixth detection means.

According to a seventh aspect of the present invention, in the multi-system air conditioner according to the first aspect, there is further provided a seventh detecting means for detecting a heating operation start by the indoor thermo-on and outputting a detection signal. The control means performs the heating refrigerant recovery operation in response to the output detection signal of the detection means.

Further, the invention of claim 8 is a multi-system air conditioner comprising an outdoor unit having a plurality of compressors including a variable capacity compressor, and a plurality of indoor units each having a refrigerant flow rate adjusting valve and a blower. In the machine, the indoor heat exchange temperature sensor that detects the heat exchanger temperature of each indoor unit, and some indoor units are stopped during operation in heating operation mode, or temporarily stopped by indoor thermo-off. , And a detection means for outputting a detection signal when the temperature of the heat exchanger in the stopped indoor unit detected by the indoor heat exchange temperature sensor becomes equal to or higher than a predetermined set value, and in response to the output detection signal of the detection means. And a control means for driving the blower of the indoor unit that is stopped.

According to a ninth aspect of the present invention, in the multi-system air conditioner according to the eighth aspect, the difference between the detected value of the heat exchanger temperature and the detected value of the indoor temperature of the indoor unit that is stopped is not less than a predetermined value. It is further characterized in that it further comprises detection means for outputting a detection signal when it becomes low, and the control means drives the blower belonging to the stopped indoor unit in response to the output detection signal of the detection means.

According to a tenth aspect of the present invention, in the multi-system air conditioner according to the eighth or ninth aspect, the control means stops the rotational drive of the blower of the indoor unit that is stopped when the drive time reaches a predetermined value. It is characterized by

According to an eleventh aspect of the present invention, in the multi-system air conditioner according to the eighth or ninth aspect, the control means controls the rotational drive of the blower of the indoor unit that is stopped to a rotational drive of a short time and a relatively long non-drive. It is characterized in that the non-rotational drive section is inertially rotated by the driving force of the rotational drive section by repeating the rotational drive.

[0019]

According to the invention of claim 1, the outdoor unit is operated for a predetermined time,
For example, when the heating operation is continuously performed for 60 minutes, it is estimated that the refrigerant has accumulated in the stopped indoor unit, the refrigerant flow rate adjusting valve of the indoor unit is opened, and the operation capacity of the variable capacity compressor is stopped in the stopped indoor unit. Increase the preset capacity according to the number of units. By doing so, it is possible to increase the capacity of the compressor to a necessary minimum in a state where the outdoor unit is expected to have a shortage of refrigerant, and to perform efficient refrigerant recovery.

According to the second aspect of the present invention, the capacity increase amount of the compressor is more rationally determined by increasing the capacity which is preset according to the capacity and the number of the indoor units in which the variable capacity compressor is stopped. Therefore, the refrigerant can be recovered more efficiently.

According to the third aspect of the present invention, when one of the discharge pipe temperatures of the compressors is maintained at a predetermined value (for example, 120 ° C.) or more for a predetermined time (for example, 5 minutes), there is a possibility of refrigerant retention. It is presumed to be present, and the heating refrigerant recovery operation is performed. By doing so, it is possible to estimate the situation in which the refrigerant is expected to be insufficient by a relatively simple detection means.

According to the invention of claim 4, when the suction side pressure of the compressor is below a predetermined value and the suction pipe temperature is above the predetermined value for a predetermined time (for example, a pressure of 2 kg / cm ² or less and a temperature of 0).
℃ or more, time 5 minutes, pressure 3kg / cm ² or less, temperature 1
When it is continued at 5 ° C. or higher for 5 minutes), it is estimated that there is a possibility of refrigerant retention, and the same action and effect as the invention of claim 3 can be achieved.

According to the fifth aspect of the present invention, while the compressor is operating in the low capacity region, the discharge pipe temperature is equal to or higher than a predetermined value (for example, 11
It is estimated that there is a possibility of refrigerant retention when 0 ° C or higher) is continued for a predetermined time (for example, 5 minutes).
It is possible to achieve the same actions and effects as the invention of.

According to the sixth aspect of the invention, it is estimated that there is a possibility of refrigerant retention when the heating operation is switched after the defrosting is completed,
The same actions and effects as the inventions of claims 3 to 5 can be achieved.

According to the invention of claim 7, when the heating operation is started by the heating thermo-on, the heating refrigerant recovery operation is performed. As a result, the same action and effect as those of the invention of claim 6 can be obtained.

Further, according to the invention of claim 8, the indoor blower is operated when the temperature of the heat exchanger of the stopped indoor unit exceeds the set value. In this way, by operating the indoor blower by using the detection output of the heat exchanger temperature of the stopped indoor unit, dew condensation can be prevented in advance.

According to the invention of claim 9, when the difference between the detected value of the heat exchanger temperature of the stopped indoor unit and the detected value of the indoor temperature exceeds a predetermined temperature, the indoor blower is rotated. By doing so, it is possible to determine the necessary conditions for operating the indoor blower under more reasonable temperature conditions and perform more reasonable (just enough) blower operation.

According to the tenth aspect of the invention, the indoor blower of the stopped indoor unit is stopped after being driven for a predetermined time. As a result, the action and effect described in claim 9 can be further improved.

According to the eleventh aspect of the present invention, the non-rotational drive section is formed by repeating the short-time rotational drive (energization of the drive motor) and the relatively long non-rotational drive (stopping the drive motor). Inertial rotation is performed by the driving force in the rotary drive section. By doing so, it is possible to achieve a safer air blower operation with a minimum amount of energy supply necessary for the rotational drive of the indoor air blower and also energy saving.

[0030]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows one configuration example of a heat pump type refrigeration cycle to which the present invention is applied, and FIG. 3 is a block diagram showing a device configuration of a control system for an air conditioner according to the present invention.

As shown in FIG. 2, the outdoor unit SG includes two compressors 1A and 1B. One compressor 1A is operated at a substantially constant speed by a commercial power source, and the other compressor 1B is shown. Variable speed operation with no inverter. Both compressors 1A and 1B constitute a variable capacity compressor capable of continuously adjusting the compression function force from zero output to an output corresponding to the sum of the individual outputs. What is necessary is that it can be configured as a variable capacity type as a whole. For example, two or more constant speed compressors are provided, or two or more variable speed compressors are provided. A variable compressor device can be constructed. The discharge side of the compressor 1A in constant speed operation is connected to the discharge side of the compressor 1B in variable speed operation via the check valve 2 and is connected to the first input end of the four-way valve 3. Both compressors 1 are connected to the second input end of the four-way valve 3.
The suction sides of A and 1B are connected via an accumulator 4. A start compensation valve 5A is connected to the compressor 1A so that it can be bypassed via the accumulator 4, and both compressors 1A and 1B are high pressure so that they can be bypassed at the output side of the check valve 2 via the accumulator 4. Release valve 5B
Is connected. The four-way valve 3 switches the refrigerant circulation direction of the indoor heat exchanger and the outdoor heat exchanger by deactivating or energizing the operation solenoid according to the cooling operation or the heating operation.

The first output end of the four-way valve 3 has two sets of outdoor heat exchangers 6A and 6B connected in parallel, a heating operation expansion valve 7, a check valve 8 for bypassing the heating operation expansion valve 7, and a liquid tank. 9 to the indoor unit group.
Here, the number of outdoor heat exchangers being two is just an example, and other numbers may be used. The indoor unit group is three indoor units U1, U2 in this embodiment.
It consists of U3. The first indoor unit U1 includes a refrigerant flow rate adjusting valve 10A and a capillary 21 which are connected in series with each other.
A and an indoor heat exchanger 11A. Similarly, the second and third indoor units U2 and U3 include refrigerant flow rate adjusting valves 10B and 10C and a capillary 21 which are connected in series with each other.
B, 21C and indoor heat exchangers 11B, 11C. The other end of the indoor heat exchangers 11A to 11C has a four-way valve 3
Are commonly connected to the second output terminals of the. The connection state shown corresponds to the cooling operation mode, and when the heating operation mode is switched by exciting the solenoid (not shown) of the four-way valve 3, the refrigerant from the compressors 1A and 1B first undergoes indoor heat exchange. Expansion valve 7 after passing through the vessels 11A to 11C
It circulates in the direction to reach the outdoor heat exchangers 6A and 6B via.

The outdoor heat exchangers 6A and 6B have outdoor blowers 12A and 1A, respectively, for promoting heat exchange with the atmosphere.
2B are provided, and indoor heat exchangers 11A to 11 are similarly provided.
Indoor blowers 13A, 13B, and 13C are provided in 1C for blowing cooling air or heating air toward the room, respectively. Each indoor blower is included in the indoor unit of the corresponding indoor heat exchanger.

In the system of FIG. 2, the indoor unit U
Equipment other than 1 to U3, that is, both compressors 1A and 1B, check valve 2, four-way valve 3, accumulator 4, valves 5A and 5B,
The outdoor heat exchangers 6A and 6B, the expansion valve 7, the check valve 8, the liquid tank 9, and the outdoor blowers 12A and 12B constitute an outdoor unit SG. The outdoor unit SG is installed outdoors.

Common suction side pressure PS of the compressors 1A and 1B
Is measured by the pressure sensor 14, and the suction pipe temperature TS is measured by the temperature sensor 15. The discharge side pressure PD of both compressors is measured by the pressure sensor 16 at the outlet side of the check valve 2, and the discharge pipe temperatures TD1 and TD2 of the compressors 1A and 1B are measured by the temperature sensors 17A and 17B, respectively. Further indoor heat exchangers 11A to 11C
Liquid side temperature (expansion valve 7 side temperature) TE1A, TE1B, T
E1C is measured by the temperature sensors 20A, 20B, and 20C, and the gas side temperature (four-way valve 3 side temperature) TE2 is measured.
A, TE2B, TE2C are temperature sensors 18A,
18B, 18C. Further, the room temperature TA1, TA2, TA3 of the room in which the indoor unit is installed is close to the temperature sensor 19A, near the air inlet of each indoor unit.
19B, 19C. Each of these measurement signals is sent to each controller described later.

FIG. 3 shows an example of the configuration of a control system for controlling the refrigeration cycle shown in FIG. Each indoor unit U1, U2, U3 is provided with an indoor controller 30A, 30B, 30C including a microprocessor. The indoor controllers 30A to 30C are provided with remote controllers (hereinafter referred to as "remote controllers") 31A, 31B, and 31C for giving an ON / OFF command for unit operation and setting a set temperature. These indoor controllers 30A to 30C include a temperature sensor 19
A signal representing the corresponding room temperature TA1 to TA3 is input from A to 19C, and the corresponding indoor heat exchangers 11A to 11C are input from the temperature sensors 20A to 20C and 18A to 18C.
C temperatures TE1A-TE1C and TE2A-TE2C
Is input to the indoor blowers 13A to 13A in the unit after performing necessary arithmetic processing according to the logic described later.
C or the opening degree of the refrigerant flow rate adjusting valves 10A to 10C is controlled.

The outdoor unit SG is provided with an outdoor controller 32 including a microprocessor. The outdoor controller 32 includes the indoor controllers 30A, 30B, 30.
Along with the command signal from C, the suction side pressure PS and the discharge side pressure PD of the compressors 1A and 1B from the pressure sensors 14 and 16, and the suction pipe temperature T from the temperature sensors 15, 17A and 17B.
Signals indicating S and the discharge pipe temperatures TD1 and TD2 are input. On the other hand, the outdoor controller 32 is connected to each indoor controller 30A, 30B, 30C,
After performing necessary arithmetic processing in accordance with commands from each indoor controller and each measurement signal, the compressor 1A is controlled to be turned on and off, its speed is adjusted to adjust the capacity of the compressor 1B, and an outdoor blower is used. 12A, 12B (generally referred to as outdoor blower 12), four-way valve 3, compressor start compensation valve 5A,
The high pressure release valve 5B is controlled to be turned on and off, and the four-way valve 3 is turned on and off (to switch between cooling operation and heating operation).

Before entering the description of the refrigerant recovery control of the present invention,
The basic operation of the apparatus shown in FIGS. 2 and 3 will be described. In the apparatus of FIG. 2, on / off commands for operating the indoor unit and the outdoor unit are issued through remote controllers 31A to 31C attached to each indoor unit. When the operation command is issued from the remote controller, the room temperature TA1 to TA3 and the set room temperatures TB1 to TB3 in each indoor controller 30A, 30B, 30C for each indoor unit (standard value preset inside or a value corrected by the remote controller) ) Is compared, and its deviation, that is, the temperature deviation ΔT
(= Room temperature TA-set room temperature TB) A step signal F (X) selected corresponding to (= room temperature TA-set room temperature TB) is transmitted to the outdoor controller 32, the openings of the refrigerant flow rate adjusting valves 10A to 10C are adjusted, and the operation is turned on. The indoor blowers (13A to 13C) of the indoor unit are controlled.

The step signal F (X) is preset corresponding to the temperature deviation ΔT during the cooling operation and the heating operation, and is set to 1 according to the sign and the absolute value of the temperature deviation ΔT.
It is classified and associated with step signals S0 to SF (the second code in the two characters is the hexadecimal representation of 0 to F) consisting of 6 steps, and the temperature deviation ΔT is less than or equal to a predetermined value during cooling operation or predetermined during heating operation. When the value is equal to or more than the value, S0 is set, so-called "thermo off" occurs, and the operation is stopped. When the temperature deviation ΔT is equal to or higher than a predetermined value during the cooling operation or equal to or lower than the predetermined value during the heating operation, a so-called “thermo on” is performed, and the cooling operation or the heating operation is performed.
The step signal F (X) (any one of the signals S1 to SF) corresponding to T is sent from the indoor controllers 30A to 30C to the outdoor controller 32. X in the step signal F (X) is a variable for specifying the indoor unit, and X = 1 in the controller 30A, X = 2 in the controller 30B, and X = in the controller 30C.
It is 3. The outdoor controller 32 uses the step signal F transmitted from the indoor controllers 30A to 30C.
(X) is referred to and converted into a required frequency basic value G (X) corresponding to the rotation speed corresponding to the capacity of the compressor. FIG. 4 shows an example of a comparison table showing the relationship between the step signal F (X) and the required frequency basic value G (X). In the example of FIG. 4, the required frequency basic value G (X) in the step signal F (X) = S0 to S2 is zero (= 0.0). The outdoor controller 32 refers to this comparison table to determine the step signal F (X).
To a required frequency basic value G (X), and further multiplied by a weight H (X) corresponding to the capacities of the indoor units U1, U2, U3 of the transmission source, and their sum Σ {G (X) · H (X )}
Is obtained, and that is the required compression function. In this embodiment, 3
Since it is assumed that one indoor unit is provided, the sum of the three values will be obtained. Further, when the capacities of the indoor units are equal, the weights H (X) have the same value, and regarding the indoor units that are not operated, F (X) = S0 is unconditionally set, and thus G (X) =
Set to 0. The outdoor controller 32 operates only the compressor 1B or both of the compressors 1A and 1B according to the required compression function force thus obtained. In that case, of the required compression functional force, the compressor 1A bears the fixed capacity portion corresponding to the constant speed rotation, and the variable speed drive compressor 1B bears the lacking portion (variable capacity portion).

An object of the present invention is to solve the refrigerant retention problem during heating operation. In order to solve this problem, the refrigerant recovery operation is performed according to the present invention. Hereinafter, a series of flows will be described with reference to the flowcharts of FIG. 1 and FIG.

In FIG. 1, first, it is checked whether or not the heating operation is performed (step 101), whether or not the defrosting operation is being performed (step 102), and whether or not all the indoor units are in the heating thermo-on (step 103). As a result of these checks, it is checked whether or not the refrigerant recovery control condition is satisfied under the condition that the heating operation is performed, the defrosting operation is not performed, and all indoor units are not in the heating thermo-on (step 104). Details of the refrigerant recovery control conditions in this step will be described later with reference to FIGS.

As for the check in step 102, if frost adheres to the outdoor heat exchanger during the heating operation, the efficiency is reduced. Therefore, when viewed from the indoor side, the defrosting operation corresponding to the cooling operation is temporarily performed. This operation mode corresponds to the cooling operation when viewed from the indoor side, and when the heating operation is performed immediately after the end, it cannot be handled in the same manner as when it is not. Therefore, it is checked whether or not the heating operation is performed immediately after the defrosting operation is completed. In the case of the heating operation after the defrosting operation is completed, the refrigerant recovery operation is performed because it is highly likely that the refrigerant remains. Also, regarding the check in step 103,
If all are thermo-on, the problem of refrigerant recovery operation does not occur.

First, the operating time T1 of the outdoor unit, which is common to the indoor units, is checked (step 3).
3). When the time T1 exceeds 60 minutes, the refrigerant recovery operation (step 100) is performed.

When the refrigerant recovery control condition is satisfied in step 104, the adjustment valve 10 (general term for the adjustment valves 10A to 10C) of the stopped indoor unit is set to the indoor controller 30.
It is opened through (inclusive of the indoor controllers 30A to 30C) (step 105), and is set to the G (X) value corresponding to the correction 1 in the following Table 1 as the required frequency basic value G (X) for the compressor 1B. Command the corresponding G (X) = 17. Table 1 Correction 1 = + 17, Correction 2 = + 9, Correction 3 = + 0 After this, the refrigerant recovery control according to the present invention is started (step 1
07).

5 to 8 show a flow of judging the refrigerant recovery control condition. The first refrigerant recovery control condition is shown in FIG.
, The discharge pipe temperature TD1 or TD2 is 120
The state in which the temperature is higher than or equal to ℃ has continued for T1 = 5 minutes (step 111, 112 and step 113, 11).
4). The second refrigerant recovery control condition is, as shown in FIG.
Step signal F (X) = S3 or S for compressor 1B
Commanded at a low value of 4, and the discharge pipe temperature TD2
Is 110 ° C. or higher for T1 = 5 minutes (steps 115, 116 and 11).
7). The third refrigerant recovery control condition is, as shown in FIG.
The state where the suction side pressure PS is 2 (kg / cm ² ) or less and the suction pipe temperature TS exceeds 0 ° C. continues for T3 = 5 minutes (steps 118 to 120), or the suction side pressure PS
Is 3 (kg / cm ² ) or less, and the suction pipe temperature TS is 1
The state where the temperature exceeds 5 ° C. continues for 5 minutes (step 121 to
123). The fourth refrigerant recovery control condition is shown in FIG.
As shown in, it is checked whether the heating thermostat is switched from the heating thermostat to the heating thermostat (step 124) or the heating operation is performed immediately after the defrosting operation is completed (step 125). This check causes a decrease in efficiency if frost adheres to the outdoor heat exchanger during heating operation, so when viewed from the indoor side, defrosting operation equivalent to cooling operation is temporarily performed, but this operation mode is from the indoor side. Looking at it, it corresponds to the cooling operation, and when the heating operation is performed immediately after the end, it cannot be treated in the same manner as when it is not. Therefore, it is checked whether or not the heating operation is performed immediately after the defrosting operation is completed. In the case of the heating operation after the defrosting operation is completed, the refrigerant recovery operation is performed because it is highly likely that the refrigerant remains. Further, when the heating thermo-on is continued for T2 = 60 minutes (> T1) as the refrigerant recovery control condition (step 1
27).

The control contents when the refrigerant recovery control (step 107) is performed by the above flow will be described below.

The refrigerant recovery control is performed by slightly increasing the rotation speed of the compressor in order to shorten the hot air blowing time in the room. Then, this control is performed by distinguishing between three patterns of "heating activation pattern" control, "during heating operation" control, and "at the time of defrosting end" control.

First, the "heating start pattern control" will be described. For the system operation at the time of starting the heating operation, the mode is divided according to the operation of the two compressors 1A and 1B, and the control is performed accordingly. α mode: operating both compressors 1A and 1B β mode: operating only variable speed compressor 1B The first control mode is applied to both α and β modes. When the heating start command is issued, the variable N for checking the number of times the thermostat is turned on and off is cleared according to FIG. 9 (N =
0) (step 201), and it is checked whether or not the heating thermostat is on (step 202). If the thermostat is off, it will be in a standby state. When the thermostat is turned on, N is incremented (N = N + 1) (step 203), and N is set at this stage.
= 1. It should be noted that the value of N is incremented by +1 each time “thermo off” → “thermo on” is repeated as described later. Therefore, the number N of times the thermostat is turned on is checked (step 204).
It is checked whether or not the required frequency basic value G (X) in the chart (1) has become 0.1 or more (205). Where G
If (X) does not exceed 0.1, it means G
This means that (X) = 0 remains, and the compressor will not be operated. Therefore, the heating start operation is stopped, and the process returns to step 201 to wait for the thermo-on again. G (X)
When it is determined that the value has increased from 0 to 0.1 or more, the required frequency basic value G (X) for recovering the refrigerant according to the present invention.
Correction 1 (= + 17) is added according to Table 1. That is, the calculation process of G (X) = G (X) +17 is performed (step 206).

If N = 2 in step 204, correction 2 (= + 9) is added. That is, G (X) =
G (X) +9 is calculated (step 207). Similarly, when N = 3, correction 3 (= + 0) is added.
That is, G (X) = G (X) +0 is calculated (step 208). When N ≧ 4, the normal control corresponding to the above-mentioned basic control based on the temperature deviation ΔT (= TA-TB) is performed under the condition of the normal operation, that is, the heating thermo-ON without performing any further correction ( Step 21
4).

In steps 206 to 208, G (X)
After the value is corrected, the maximum value of this G (X) value (corresponding to the maximum speed of the compressor) is set to 29.0, and G after each correction is set.
G (X) ≦ 29.0 so that the (X) value does not exceed it
Check whether or not (step 209), and if G
If (X)> 29.0, G (X) = 29.0 is corrected (step 210). The heating start-up operation is performed under the above conditions (step 211). When this start-up operation is started, the operation time is measured and it is checked whether 20 minutes have elapsed (step 212). If the thermostat is turned off within 20 minutes (step 213), step 202
Return to and wait for the next thermoon. When the thermostat is turned on, N = N + 1 increment processing (step 203) is performed as described above, and correction is performed by adding a correction value one step higher with respect to the G (X) value (that is, a smaller G (X) value. To). 20 in step 212
When the minutes have elapsed, the process proceeds to step 206, and the correction of G (X) is corrected by the correction 1 as in the case of the first activation, that is, G (X) =
The process of G (X) +17 is performed. When N ≧ 4 in step 204, it is considered that the heating start operation and the refrigerant recovery operation have ended, and the heating normal operation according to the required frequency basic value G (X) determined based on the thermo-on / off and the temperature deviation ΔT is started ( Step 214).

After the heating is started in FIG. 10, after 20 minutes have passed with the same starting operation condition, the process returns to step 201 (step 212). If the thermostat is turned off within 20 minutes under the same start-up operating condition, step 20
Return to step 2 (step 213). When the thermostat is not turned off within 20 minutes, the pressure PS on the suction side of the compressor is monitored (step 221), and when PS <0.3 (kg / cm ² ), the correction value of the G (X) value If the correction is 3, the process returns to step 211 (step 222), and during the thermo-ON of the correction 3, 20 minutes is not stopped even if PS <0.3. In step 222, other than the correction 3 (that is, the heating start operation is not performed and the thermostat is not turned off within 20 minutes,
When the suction side pressure PS is less than 0.3, stop control is performed (step 223), the restart prevention timer is started (step 224), and the correction is increased by one step (the + numerical value is decreased) ( The process returns to step 225) and step 201 (FIG. 9).

The second control mode is applied to the α mode and the β mode of the compressor 1A off condition.

In this case, as shown in FIG. 11, when the operation is started, the step signal command S5 in FIG. 4 is sent to the variable speed compressor 1B under the condition of thermo-on (step 231) (step 232). The time is counted from the sending of this command (step 233), and after 2 minutes, the normal heating operation according to the required frequency basic value G (X) determined based on the temperature deviation ΔT is started (steps 233, 214).

The third control mode is the compressor 1
This is a heating start pattern under the A-on condition, and only the β mode is applied.

As shown in FIG. 12, when the operation is started, the step signal S5 command in FIG. 4 is sent to the compressor 1B under the condition of thermo-on (step 241), and the compressor start compensation valve 5A is issued an on (open) command. (Step 2
42). The time is counted from the sending of this command, and when 1 minute has elapsed (step 243), the compressor 1A is turned on and the high pressure release valve 5B is turned on (open) (step 244). When 5 seconds have passed after this ON command (step 245), the start compensation valve 5A is turned off (closed) (step 246). Further, after 2 minutes have passed after the ON command to the compressor 1A (step 247), the high pressure release valve 5B is turned off (closed) (step 248). Thereafter, normal operation is started according to the required frequency basic value G (X) determined based on the temperature deviation ΔT (step 214).

The three modes have been described above. Next, the heating activation pattern cancellation control will be described with reference to FIG. The first release condition is that the discharge side pressure PD of the compressor becomes 20 (kg / cm ² ) or more (step 2).
61). The second release condition is that at least one of the discharge pipe temperatures TD1 and TD2 of the compressors 1A and 1B exceeds 115 (° C.) (step 262). The third cancellation condition is that there is no heating operation command from the indoor side (step 263). The fourth cancellation condition is that the cooling operation mode is selected on the indoor side (step 264). Finally, the fifth cancellation condition is that the correction value 3 is selected in Table 1, the room temperature TA reaches the set value TB, and the heating thermostat is off (step 265). When any of the six conditions described above is satisfied, the heating activation pattern control is released (step 266).

Next, the refrigerant recovery control during the "heating operation" will be described. In this case, as shown in FIG. 14, the constant speed compressor 1A is turned off, and the variable speed compressor 1B is independently operated by the S3 command (minimum rotation speed command) in FIG. 4 (step 301). After doing that for 2 minutes (step 3
02), the start compensation valve 5A is turned on (opened) (step 303). When this state is continued for 30 seconds (step 304), an ON command is issued to the compressor 1A and the high pressure release valve 5B (step 305), and the ON command
After 5 seconds, the start compensation valve 5A is turned off (steps 306, 30).
7), and 2 minutes after the compressor 1A is turned on in step 305, the high pressure release valve 5B is turned off (step 30).
8, 309). During this period, the S3 command issued in step 301 continues. After the valve 5B is turned off, the normal operation is started (step 214).

Next, the refrigerant recovery control at the "end of defrosting" will be described. In this case, as shown in FIG. 15, instead of immediately shifting to the normal heating operation after defrosting is completed (the four-way valve 3 is switched from OFF to ON), the compressor 1A is turned on and the S3 command to the compressor 1B is issued. (FIG. 4) is continued for 2 minutes (steps 311 and 312), the refrigerant recovery control is performed, and then the normal operation (step 214) is performed. The refrigerant recovery control is also related to the control of the indoor unit, and when the refrigerant recovery control is started due to the completion of defrosting, the refrigerant recovery command is issued to the outdoor controller 3.
The controller 30 of the indoor unit whose operation is stopped from 2
It is transmitted to (the generic name of the controllers 30A to 30C) (step 315). This command continues for at least 5 minutes (step 316). After that, if the heating refrigerant recovery control ending condition described later is satisfied, the transmission of the refrigerant recovery control command is stopped at that time (steps 317 and 319).
Even when the heating refrigerant recovery control termination condition is not satisfied in step 317, the transmission of the refrigerant recovery control command is stopped after a further 5 minutes (10 minutes have elapsed) from the time point of 5 minutes in step 316 (step 3).
18, 319).

Next, the conditions for ending the heating refrigerant recovery control will be described. As shown in FIG. 16, the heating refrigerant recovery control ends when one of the following conditions is satisfied. The first case is when the heating activation pattern control release condition described with reference to FIG. 13 is satisfied (step 321). Second
In this case, 10 minutes have passed since the heating refrigerant recovery control was started (step 322). The third case is when the system is stopped, the thermostat is turned off, or the cooling operation is performed (step 323). When either of these conditions is satisfied, the heating refrigerant recovery control is ended (step 324).
15 minutes after the end of this refrigerant recovery control (even if the system is stopped or the thermostat is off or the cooling operation is continued)
Prohibits the refrigerant recovery control so that the next refrigerant recovery control is not performed even if the refrigerant recovery control condition is satisfied (steps 325 and 326). When 15 minutes have passed after the end of the refrigerant recovery control, the compression function force correction value is cleared (step 3
27) When the prohibition of the refrigerant recovery control is released and the control start condition is satisfied, the refrigerant recovery control can be restarted (step 328).

According to the above-mentioned embodiment, the state in which the outdoor unit SG is estimated to be insufficiency of the refrigerant is detected from the information from each sensor, and the operating speed of the compressor at the time of recovery control is determined according to the conditions. By changing the amount, it is possible to improve the refrigerant recovery capability from the indoor unit that is not operating and to perform efficient refrigerant recovery.

Next, a modified embodiment of the present invention will be described. In the embodiment described here, in order to prevent dew condensation in the indoor unit that is stopped, the blower 13 is turned on / off according to the detected temperature TE1 on the heat exchange liquid side.

FIG. 17 shows a flowchart of the on / off control of the blower 13. First, it is checked whether the indoor unit U is stopped (step 35).
1). When operating, the blower attached to it is also operating, the air in the indoor unit is circulating, and there is no need to perform the blower operation according to this embodiment, so the standby state is entered. When it is confirmed that the indoor unit U has stopped,
The heat exchange liquid side temperature TE1 is detected (step 352), and it is checked whether it is equal to or higher than the set temperature α (step 353). As a result of this check, if TE1 ≧ α, the blower is turned on (step 354), and if TE1 <α, the blower is kept off (step 355).

In the above on / off control of the blower 13, the blower 13 may be turned on or off at the same set temperature α both when the temperature rises and when the temperature falls, without giving a hysteresis characteristic to the detected temperature. The blower 13 may be turned on at the set temperature α when the temperature rises, and may be turned off at the set temperature β which is slightly lower than the set temperature α when the temperature drops to have a hysteresis characteristic. In any case, when the heat exchange liquid side temperature TE1 of the indoor unit which is not in operation is equal to or higher than the predetermined value, the blower 13 is turned on to circulate air in the indoor unit U and the heat exchange liquid side temperature TE1 is set to the predetermined value. The blower 13 is turned off in the following cases.

Another modified embodiment will be described. FIG. 17
In place of the heat exchange liquid side temperature TE1 in the room temperature sensor TA
Is used as a reference, the difference between the heat exchange liquid side temperature TE1 and the room temperature sensor TA is used, and the difference is set value γ (<α).
When the above is reached, the blower 13 is operated. Even in this case, the same operation and effect as described with reference to FIG. 17 can be achieved.

Further, as shown in FIG. 18 and FIG.
In the embodiment of FIG. 17, when the blower is turned on under the condition of TE1 ≧ α (step 354), the OFF control is not based on the heat exchange liquid side temperature TE1, but the operation time is counted from the time the blower is turned on (step 356),
When it reaches the preset time Ton, the heat exchange liquid side temperature T
Blower off regardless of E1 (step 35
Even in the case of 5), substantially the same actions and effects can be achieved.

Furthermore, when the blower of the stopped indoor unit is rotated, as shown in FIG. 20, the blower 13 is energized with a relatively short energizing time Ton in order to prevent the danger of the operator as much as possible. The same or slightly longer non-energization time Toff is repeated, and the non-energization time Toff
In the off state, the air in the indoor unit U is circulated by continuing to rotate by inertia due to the rotation during the energization time Ton. In other words, the blower 13 is not energized continuously, but is energized at intervals such that the blower can rotate at least. As a result, when the blower 13 is touched by a person's hand, the blower 13 cannot rotate, and it is possible to circulate the air in the indoor unit U with a small number of rotations while preventing the occurrence of a personal injury. .

Thus, according to the above embodiment, it is possible to prevent dew condensation in the indoor unit by controlling the indoor blower without using a heat insulating material or the like.

[0068]

According to the invention of claim 1, when the outdoor unit is continuously heated for a predetermined time, it is estimated that the refrigerant has accumulated in the stopped indoor unit, and the refrigerant flow rate adjusting valve of the indoor unit is estimated. And the operating capacity of the variable capacity compressor is increased by a preset value according to the number of indoor units that are stopped. By doing so, it is possible to increase the capacity of the compressor to a necessary minimum in a state where the outdoor unit is expected to have a shortage of refrigerant, and to perform efficient refrigerant recovery.

According to the second aspect of the present invention, the capacity increase amount of the compressor is more rationally determined by increasing the capacity that is preset according to the capacity and the number of the indoor units in which the variable capacity compressor is stopped. Therefore, the refrigerant can be recovered more efficiently.

According to the third aspect of the invention, when one of the discharge pipe temperatures of each compressor is kept at a predetermined value or more for a predetermined time, it is estimated that there is a possibility of refrigerant retention, and the heating refrigerant recovery operation is performed. Assumed to be performed. By doing so, it is possible to estimate the situation in which the refrigerant is expected to be insufficient by a relatively simple detection means.

According to the fourth aspect of the present invention, it is estimated that there is a possibility of refrigerant retention when the pressure on the suction side of the compressor is below a predetermined value and the suction pipe temperature is above the predetermined value for a predetermined time. The same action and effect as the invention of claim 3 can be achieved.

According to the fifth aspect of the present invention, when the compressor is operating in the low capacity region and the discharge pipe temperature continues to be equal to or higher than a predetermined value for a predetermined time, it is estimated that there is a possibility of refrigerant retention. The same actions and effects as those of the fourth aspect of the invention can be achieved.

According to the sixth aspect of the present invention, it is estimated that there is a possibility of refrigerant retention at the time of switching the heating operation after the completion of defrosting.
The same actions and effects as the inventions of claims 3 to 5 can be achieved.

According to the invention of claim 7, when the heating operation is started by the heating thermo-on, the heating refrigerant recovery operation is performed. As a result, the same action and effect as those of the invention of claim 6 can be obtained.

Further, according to the invention of claim 8, the indoor blower is operated when the temperature of the heat exchanger of the stopped indoor unit exceeds the set value. In this way, by operating the indoor blower by using the detection output of the heat exchanger temperature of the stopped indoor unit, dew condensation can be prevented in advance.

According to the ninth aspect of the invention, when the difference between the detected value of the heat exchanger temperature of the indoor unit that is stopped and the detected value of the indoor temperature exceeds a predetermined temperature, the indoor blower is rotated. By doing so, it is possible to determine the necessary conditions for operating the indoor blower under more rational temperature conditions and perform more rational fan operation without excess or deficiency.

According to the tenth aspect of the present invention, the indoor blower of the stopped indoor unit is stopped after being driven for a predetermined time. As a result, the action and effect described in claim 9 can be further improved.

According to the eleventh aspect of the present invention, the non-rotational drive section is inertially rotated by the driving force of the rotation drive section by repeating the short-time rotation drive and the relatively long non-rotational drive. By doing so, it is possible to achieve a safer air blower operation with a minimum amount of energy supply necessary for the rotational drive of the indoor air blower and also energy saving.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of a control flow of an air conditioner according to the present invention.

FIG. 2 is a system configuration diagram showing a refrigeration cycle to which the present invention is applied together with various sensors.

FIG. 3 is a block diagram of a control device for an air conditioner according to the present invention.

FIG. 4 is a chart showing a relationship between a step signal transmitted from an indoor unit and a required frequency basic value.

5 is a flowchart showing details of part of step 104 in FIG.

FIG. 6 is a flowchart showing details of part of step 104 in FIG.

FIG. 7 is a flowchart showing details of part of step 104 in FIG.

FIG. 8 is a flowchart showing details of part of step 104 in FIG.

FIG. 9 is a flowchart showing a part of a control flow applied to the first operation mode during heating start-up operation.

FIG. 10 is a flowchart showing another part of the control flow applied to the first operation mode during the heating start-up operation.

FIG. 11 is a flowchart showing a control flow applied to a second operation mode during heating startup operation.

FIG. 12 is a flowchart showing a control flow applied to a third operation mode during heating start-up operation.

FIG. 13 is a flowchart showing a heating start pattern release control flow.

FIG. 14 is a flowchart showing a flow of refrigerant recovery control during heating operation.

FIG. 15 is a flowchart showing a flow of refrigerant recovery control at the end of the defrosting operation.

FIG. 16 is a flowchart showing the control content of refrigerant recovery control.

FIG. 17 is a flowchart showing a control flow according to a modified embodiment of the present invention.

FIG. 18 is a flowchart showing a modification of the embodiment of FIG.

FIG. 19 is a diagram showing one control mode of the embodiment of FIG. 18.

FIG. 20 is a diagram for explaining a modified embodiment of the embodiment of FIG.

[Explanation of symbols]

 GS Outdoor unit 1A Constant speed compressor 1B Variable speed compressor 3 Four-way valve 6A, 6B Outdoor heat exchanger 7 Expansion valve 8 Check valve 10A, 10B, 10C Refrigerant flow control valve 11A, 11B, 11C Indoor heat exchanger 12A, 12B outdoor blower 13A, 13B, 13C indoor blower U1, U2, U3 indoor unit 14 suction pressure sensor 15 suction temperature sensor 16 discharge pressure sensor 17A, 17B discharge temperature sensor 18A, 18B, 18C indoor heat exchange temperature sensor 19A, 19B, 19C Room temperature sensor 20A, 20B, 20C Indoor heat exchange temperature sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norifumi Iimura 336 Tatehara, Fuji City, Shizuoka Prefecture Toshiba A ・ V ・ E ・ E Co., Ltd. Fuji Office

Claims (11)

[Claims] 1. A multi-system air conditioner comprising an outdoor unit having a plurality of compressors including a variable capacity compressor and a plurality of indoor units each having a refrigerant flow rate adjusting valve, in a heating operation mode. When some indoor units are stopped during operation or temporarily stopped due to indoor thermostat off, the first detection means for detecting that and the outdoor unit continue heating operation for the first set time. When I did
The second detection means for detecting it and the refrigerant staying in the stopped indoor unit are collected, so that the refrigerant in the stopped indoor unit is responsive to the output detection signals of the first and second detection means. And a control means for performing a heating refrigerant recovery operation for opening the flow rate adjusting valve and increasing the operation capacity of the variable capacity compressor set in advance according to the number of stopped indoor units. Multi-system air conditioner. 2. The multi-system air conditioner according to claim 1, wherein the control means increases the preset capacity of the variable capacity compressor in accordance with the capacity and the number of stopped indoor units. And a multi-system air conditioner. 3. The multi-system air conditioner according to claim 1, wherein a discharge temperature sensor for detecting a discharge pipe temperature of each compressor, and a temperature value detected by the discharge temperature sensor being equal to or higher than a first set temperature. And a third detecting means for outputting a detection signal when the second setting time shorter than the first setting time is continued, and the control means in response to the output detection signal of the third detecting means. Performs a heating refrigerant recovery operation of the multi-system air conditioner. 4. The multi-system air conditioner according to claim 1, wherein a suction pressure sensor for detecting a suction side pressure of the compressor, a suction temperature sensor for detecting a suction pipe temperature of the compressor, and the suction pressure sensor. When the detected pressure value of is less than or equal to the first pressure set value and the detected temperature value of the suction temperature sensor is equal to or higher than the set temperature for a third set time shorter than the first set time. A multi-system air conditioner, further comprising: a fourth detection means for outputting, wherein the control means performs a refrigerant recovery operation in response to an output detection signal of the fourth detection means. 5. The multi-system air conditioner according to claim 1, wherein a temperature detected by the discharge temperature sensor is lower than the first set temperature while the compressor is operating in a low capacity region. A fifth signal for outputting a detection signal when the above state is continued for a fourth set time shorter than the first set time
The multi-system air conditioner, further comprising: a detection means, wherein the control means performs a heating refrigerant recovery operation in response to the output detection signal of the fifth detection means. 6. The multi-system air conditioner according to claim 1, further comprising sixth detection means for detecting switching to heating operation after defrosting and outputting a detection signal. The multi-system air conditioner, wherein the control means performs the heating refrigerant recovery operation in response to the output detection signal of the detection means. 7. The multi-system air conditioner according to claim 1, further comprising seventh detection means for detecting heating operation activation by indoor thermoon and outputting a detection signal.
A multi-system air conditioner in which the control means performs a heating refrigerant recovery operation in response to the output detection signal of the seventh detection means. 8. A multi-system air conditioner comprising: an outdoor unit having a plurality of compressors including a variable capacity compressor; and a plurality of indoor units each having a refrigerant flow rate control valve and a blower. An indoor heat exchanger temperature sensor that detects the heat exchanger temperature, and some indoor units are stopped during operation in the heating operation mode, or temporarily stopped by indoor thermo-off, and the indoor heat exchanger temperature Detecting means for outputting a detection signal when the heat exchanger temperature of the stopped indoor unit detected by the sensor exceeds a predetermined set value, and the stopped indoor unit in response to the output detection signal of this detecting means And a control means for driving the fan of the multi-system air conditioner. 9. The multi-system air conditioner according to claim 8, wherein a detection signal is output when the difference between the detected value of the heat exchanger temperature of the indoor unit that is stopped and the detected value of the indoor temperature exceeds a predetermined value. The multi-system air conditioner, further comprising: a detection unit that outputs the detection unit, the control unit driving a blower belonging to the stopped indoor unit in response to an output detection signal of the detection unit. 10. The multi-system air conditioner according to claim 8 or 9, wherein the control means stops the rotational drive of the fan of the indoor unit which is stopped when the drive time reaches a predetermined value. A multi-system air conditioner. 11. The multi-system air conditioner according to claim 8 or 9, wherein said control means performs rotational drive of the blower of the indoor unit that is stopped, rotational drive for a short time and non-rotative drive for a relatively long time. A multi-system air conditioner characterized in that the non-rotational drive section is made to rotate by inertia by the driving force of the rotational drive section by repeating the cycle.