JP5072386B2 - Multi-type air conditioner - Google Patents

Description

  The present invention relates to a multi-type air conditioner that includes a plurality of indoor unit units that eject conditioned air by air conditioning operation (cooling operation, heating operation, and dehumidifying operation) and that can perform different operation control for each indoor unit.

An air conditioner that performs indoor air conditioning and dehumidification (hereinafter collectively referred to as “air conditioning”) has a configuration in which an indoor unit and an outdoor unit are connected by refrigerant piping and electrical wiring. Such an air conditioner uses a heat pump that forms a refrigerant circulation circuit with a compressor, an outdoor heat exchanger, a throttle mechanism, an indoor heat exchanger, and a four-way valve as main components, and is sent from the compressor. The desired air conditioning operation is performed by switching the circulation direction of the refrigerant by operating the four-way valve.
In such an air conditioner, a single type of configuration in which one indoor unit is connected to a set of outdoor unit and a configuration in which a plurality of indoor unit units each enabling independent operation control are connected There are multiple types.
Japanese Patent No. 2945730

  The multi-type air conditioning system includes a plurality of indoor unit units for one outdoor unit, and each indoor unit is installed in each room. Although the room temperature is lowered by cooling operation in the room using the indoor unit, the indoor unit is not used and the low pressure side of each indoor unit communicates with the indoor space under high temperature and high humidity conditions. Therefore, the piping is cooled during the cooling operation. If the heat insulation performance deteriorates due to insufficient performance or crushing of the pipe heat insulating material in the pipe, the surface of the heat insulating material may condense due to high-temperature and high-humidity indoor air, resulting in water leakage.

  This invention is made | formed in view of the said situation, and it aims at providing the multi-type air conditioning apparatus which can prevent dew condensation of a transition pipe.

A multi-type air conditioner according to the present invention includes an outdoor unit including a compressor that compresses a refrigerant, and a plurality of indoor units including an indoor heat exchanger, and outputs the compressor output of the outdoor unit. In the multi-type air conditioner in which a control command to be controlled is output from each indoor unit, the temperature of the indoor heat exchanger is lower than a predetermined threshold, and the outdoor temperature is higher than the predetermined threshold. In this case, a control unit that performs restriction control for restricting the compressor output required by each indoor unit is provided.

  The control unit shifts to the limit control mode when the conditions are likely to cause condensation. Under this restriction control, the compressor output is restricted, so that condensation on the surface of the heat insulating material can be suppressed even when the low-pressure side transition pipe is exposed to high temperature and high humidity conditions.

In the above invention , the restriction control is performed when the temperature condition lasts for a predetermined time or more.

  According to this configuration, the start condition is maintained for a predetermined time, and when the condition is surely met, the control shifts to the limit control.

In the above invention , in the restriction control mode, a restriction range of the compressor output is accumulated according to a predetermined temperature condition to restrict the output of the compressor.

  As the temperature condition for accumulating the limit width, for example, the indoor heat exchanger temperature is used. An upper limit may be set for the limit range of the compressor output. Moreover, you may make it ensure the minimum output of the said compressor output. By accumulating and limiting the output, the compressor output can be limited to an appropriate level.

In the above invention , the restriction control is canceled when the restriction control start condition is not satisfied.

  When the start condition is no longer satisfied due to an increase in the room temperature or the like, the restriction control is canceled to ensure the indoor cooling state.

  According to the multi-type air conditioner of the present invention, it is possible to prevent condensation on the transition pipe by appropriately suppressing the output of the compressor. At this time, since the start and release conditions of the restriction control mode are appropriately set, it is possible to prevent the cooling performance (feeling) from being deteriorated. Further, by accumulating the limit widths, it is possible to limit the compressor output to an appropriate level within a range that does not reduce the feeling.

  Hereinafter, an embodiment of a multi-type air conditioner according to the present embodiment will be described with reference to the drawings. In the multi-type air conditioner of the present embodiment, when the indoor heat exchange temperature and the outside air temperature are under a predetermined condition, the rotational speed of the compressor related to the indoor air conditioning is decreased by a predetermined level within a range in which the feeling does not deteriorate. In this way, dew condensation on the crossover piping is prevented.

  FIG. 1 is an explanatory diagram illustrating an example of the overall configuration of a multi-type air conditioner. This multi-type air conditioner includes an outdoor unit 10 and a plurality of indoor unit units 20 (two indoor unit units 20A and 20B in the illustrated example) connected to the outdoor unit 10. Configured. The indoor unit 20 and the outdoor unit 10 are connected by a refrigerant pipe 30 through which a refrigerant flows, electric wiring (not shown), and the like.

  The outdoor unit 10 includes a compressor 11 that compresses and sends out a refrigerant, a four-way valve 12 that switches a circulation direction of the refrigerant, an outdoor heat exchanger 13 that exchanges heat between the refrigerant and the outside air, and a throttling mechanism. The functioning electronic expansion valve 14 is a main component, and further, the muffler 15 disposed in the discharge side piping of the compressor 11 for the purpose of silencing, and the suction pipe piping of the compressor 11 for the purpose of silencing. A suction muffler 16 provided and an outdoor control unit 17 that performs various operation controls are provided. In addition, the outdoor unit 10 is provided with devices such as an outdoor fan, a receiver, a service valve, and a strainer (not shown) and sensors such as a temperature sensor.

The indoor unit 20 is configured such that a casing and other devices such as an indoor fan (not shown) are housed in the casing in addition to the indoor heat exchanger 21 and the indoor control unit (control unit) 22. The indoor heat exchanger 21 includes a two-phase flow part temperature sensor 23 that detects the temperature of the two-phase flow part, a gas phase part temperature sensor 24 that detects the temperature on the gas phase side, and an indoor air suction temperature sensor 25. The temperature data detected by these temperature sensors is input to the indoor control unit 22. Here, the two-phase flow part temperature sensor 23 is a temperature sensor attached to the intermediate part of the path of the indoor heat exchanger 21, and detects the pressure saturation temperature in the two-phase flow part. The indoor air suction temperature sensor 25 detects the temperature of the indoor air sucked into the indoor unit 20, that is, the temperature of the indoor air to be air-conditioned from now on, so that an appropriate position in the flow path from the suction port to the indoor heat exchanger 21 is detected. It is a temperature sensor attached to.
In addition, A and B attached to each code | symbol in a figure shall be used only when distinguishing and explaining two indoor unit units.

  The indoor unit 20 guides indoor air sucked by an indoor fan to the indoor heat exchanger 21 and passes it through the room, and the conditioned air heat-exchanged with the refrigerant supplied from the outdoor unit 10 described above is indoors. It is configured to blow out. The two indoor unit units 20A and 20B are installed in different air-conditioning target rooms, and are configured to be able to perform different operation control depending on the situation of each room. Here, the different operation control means that either one of the cooling operation or the heating operation is selected, and the operation control corresponding to the air conditioning load different for each room is performed, and the two indoor unit 20A, 20B does not perform different air-conditioning operations simultaneously, such as heating operation and cooling operation.

The two indoor unit units 20A and 20B are connected to refrigerant pipes 30A and 30B branched by a pipe connector 31 and a header 32 in the outdoor unit 10, respectively. In addition, each refrigerant pipe 30A, 30B in the outdoor unit 10 is provided with electronic expansion valves 14A, 14B that operate independently between the outdoor heat exchanger 13 and the indoor unit 20A, 20B. ing.
In the outdoor unit 10 described above, the intake pipe sensor 11a and the discharge pipe sensor 11b of the compressor 11, the outdoor heat exchange sensor 13a provided on the liquid phase side of the outdoor heat exchanger 13, and the outside air temperature are detected. The detected temperature is input to the outdoor control unit 17.

Below, the effect | action of the multi-type air conditioning apparatus of the structure mentioned above is divided and demonstrated in each case at the time of heating operation and air_conditionaing | cooling operation.
First, the air conditioning operation during the heating operation will be described together with the refrigerant flow indicated by arrows in the drawing. The heating operation and the cooling operation are selectively switched according to the flow direction of the refrigerant that changes depending on the operation of the four-way valve 12.

  Now, the refrigerant made into a high-temperature and high-pressure gas by the compression of the compressor 11 passes through the muffler 15 and the four-way valve 12 and is guided to the header 32. The gaseous refrigerant is further guided from the header 32 to the indoor heat exchanger 21 of the indoor unit 20 and exchanges heat with the indoor air to dissipate heat. The high-temperature and high-pressure liquid refrigerant condensed by this heat release is reduced in pressure when passing through the electronic expansion valve 14 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant and flows into the outdoor heat exchanger 13.

When the gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 13 passes through this heat exchanger, it exchanges heat with outdoor air (hereinafter referred to as “outdoor air”), absorbs heat, evaporates, and evaporates to a low temperature. It becomes a low-pressure gas refrigerant. This gaseous refrigerant passes through the four-way valve 12 and the suction muffler 16 and is sucked into the compressor 11, and then circulates in the refrigeration cycle of the multi-type air conditioner while repeating state changes in the same process.
In such heating operation, when the indoor unit 20A, 20B is operated simultaneously under different air conditioning loads, the refrigerant circulation amount distributed to both units is adjusted by the opening degree of the electronic expansion valves 14A, 14B. . In addition, about the indoor unit 20 in operation stop, the electronic expansion valve 14 connected to the unit is fully closed or slightly opened.

Next, the cooling operation will be briefly described. This cooling operation is performed by operating the four-way valve 12 and switching the refrigerant circulation direction from the above-described heating operation.
In this cooling operation, the refrigerant flow from the compressor 11 to the four-way valve 12 is the same as that in the heating operation. However, the high-temperature and high-pressure gas-phase refrigerant that has exited the four-way valve 12 is guided to the outdoor heat exchanger 13 and the outdoor operation. Exchange heat with air. By this heat exchange, the high-temperature and high-pressure gaseous refrigerant gives heat to the outdoor air to be condensed and liquefied, and becomes a high-temperature and high-pressure liquid refrigerant. The liquid refrigerant is depressurized by passing through the electronic expansion valve 14, becomes a low-temperature low-pressure gas-liquid two-phase refrigerant, passes through the refrigerant pipe 30, and is sent to the indoor heat exchanger 21 of the indoor unit 20 again.

The low-temperature and low-pressure gas-liquid two-phase refrigerant exchanges heat with the indoor air in the indoor heat exchanger 21, removes heat from the indoor air to be air-conditioned, cools the indoor air, and evaporates and evaporates itself to reduce the temperature. It becomes a low-pressure gas refrigerant.
This gaseous refrigerant passes through the header 32, the four-way valve 12, and the suction muffler 16, and is again sucked into the compressor 11, and thereafter circulates in the refrigeration cycle of the multi-type air conditioner while repeating state changes in the same process.

In the above-described multi-type air conditioner of the present embodiment, each indoor control unit 22 requests the outdoor control unit 17 to output the compressor 11 as an indoor unit command rotational speed, and the outdoor control unit 17 performs the entire compressor. The rotational speed is calculated and output to the compressor 11.
At this time, the following control for shifting to the restriction control mode is performed in which the output (indoor unit command rotational speed) of the compressor 11 commanded from the indoor control unit 22 during the cooling operation is appropriately limited by the outdoor control unit 17. Done. Incidentally, it carried out separately for the control of each indoor unit 20 below.

The control flow by the outdoor control unit 17 is shown in FIGS.
First, normal operation is started (step A1). It is determined whether or not a predetermined limited control mode start condition is satisfied (step A2). The restriction control mode start condition is determined as follows.

The condition is when the indoor heat exchanger saturation temperature (TIP1) detected by the two-phase flow part temperature sensor 23 is α ° C. or lower and the outside air temperature is β ° C. or higher. These values of α and β are determined from the dew point temperature at which the cooling performance (operation feeling) does not deteriorate and the surface of the heat insulating material is not condensed, and the characteristics of the heat insulating material.
For example, assume that all of the following conditions are satisfied.
-Operation mode: Cooling-Outdoor rotational speed: The compressor 11 of the outdoor unit 10 is operating at a rotational speed other than 0 rps-Indoor heat exchange sensor temperature 1 (TIP1) detected by the two-phase flow part temperature sensor 23 Is less than 13 ° C ・ Detected temperature TO of external temperature sensor 18 is 23 ° C or higher

  If the above condition is satisfied, it is determined whether the temperature condition of the start condition continues for 5 minutes (step A3). If the determination is YES, the process proceeds to the cooling room air low pressure control (step B1). If the determinations in steps A2 and A3 are NO, the process returns to step A1 and normal operation is performed.

  After starting the cooling room air low pressure control, it is first determined whether or not the release condition is satisfied (step B2). If the determination is YES, the operation is switched to the normal cooling operation in step B3. At this time, an integration ΣΔrps of a correction value (rotation number) described later is returned to zero.

The release condition is when one of the following conditions is satisfied.
Operation mode: When heating is stopped, outdoor rotational speed: When the rotational speed of the compressor 11 of the outdoor unit 10 becomes 0 rps, Indoor heat detected by the two-phase flow part temperature sensor 23 to be controlled When AC sensor temperature 1 (TIP1) is 13 ° C or higher ・ Detected temperature TO of external temperature sensor 18 is lower than 23 ° C

When the determination in step B2 is NO, the rotational speed command is corrected as follows.
It is determined that the sampling timer is up by 5 minutes (step B4). If 5 minutes have not elapsed, the indoor unit command rotational speed is continuously output (step B5). If the determination in step B4 is YES, the temperature condition is determined (step B6). When the detected temperature TIP1 ≧ 13 ° C. of the two-phase flow part temperature sensor 23 or the detected temperature (external temperature) <23 ° C. of the external temperature sensor 18 is switched to the normal operation in step B3. If 10 ° C. ≦ TIP1 <13 ° C., the process proceeds to step B7, where the correction value Δrps = 0. If TIP1 <10 ° C., the process proceeds to step B8, where the correction value Δrps = 8.

After steps B7 and B8, ΣΔrps ≧ 120 is determined in step B9. ΣΔrps, which is the accumulation of the correction value Δrps, is calculated. If this value is 120 or more (when the determination is YES), 120 is used as the upper limit, and the correction is performed by subtracting from the indoor unit command rotational speed (step B10). If the determination in step B9 is NO, ΣΔrps is subtracted from the indoor unit command rotational speed as it is for correction and output (step B11). Next, in step B12, the indoor unit command rotational speed ≦ 20 rps is determined. If YES, the lower limit of the indoor unit command rotational speed is set to 20 rps in step B13. Decreasing the cooling feeling can be prevented by determining the lower limit. In addition, you may change suitably the minimum of the indoor unit instruction | command rotation speed here from the correlation with a capacity | capacitance (a heat exchanger and air volume) and heat exchanger sensor temperature (TIP1). For example, in order to improve the feeling, the lower limit value of the number of rotations may be increased as the capacity increases.
In the case of NO in step B12 and after step B13, the process returns to the beginning of the cooling room air low pressure control.

  As described above, in the multi-type air conditioner of the present embodiment, the output of the compressor 11 (indoor unit command rotational speed) commanded from the indoor control unit 22 is appropriately suppressed, thereby preventing dew condensation on the transition pipe. be able to. At this time, since the start and release conditions of the restriction control mode are appropriately set, it is possible to prevent the cooling performance (feeling) from being deteriorated. Further, by subtracting the value ΣΔrps obtained by accumulating the correction value Δrps, it is possible to limit the compressor output to an appropriate level within a range that does not reduce the feeling.

It is a lineblock diagram showing one embodiment of a multi type air harmony device concerning the present invention. It is the flowchart which showed the start conditions of the restriction | limiting control mode driving | operation by the multi type air conditioning apparatus. It is the flowchart which showed the cancellation | release conditions of the restriction | limiting control mode driving | operation by the multi type air conditioning apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Outdoor unit, 11 ... Compressor, 18 ... External temperature sensor, 20 ... Indoor unit, 22 ... Indoor control part (control part), 23 ... Two-phase flow part temperature sensor

Claims (3)

An outdoor unit having a compressor for compressing the refrigerant;
A plurality of indoor unit units including an indoor heat exchanger,
In the multi-type air conditioner controlled by the outdoor unit based on a control command output from each indoor unit, the compressor output of the outdoor unit,
Limit control for limiting the compressor output required by each indoor unit when the temperature of the indoor heat exchanger is lower than a predetermined threshold and the outdoor temperature is higher than a predetermined threshold. A control unit to perform ,
In the limit control mode, the limit width of the compressor output is determined to be 0 or other according to a predetermined temperature condition, and the determined limit width is accumulated to limit the output of the compressor. Harmony device.   The multi-type air conditioner according to claim 1, wherein the restriction control is performed when the temperature condition continues for a predetermined time or more. The multi-type air conditioner according to claim 1 or 2 , wherein the restriction control is canceled when the restriction control start condition is not satisfied.

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