JP2008261553A - Multi-room type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in which, in a multi-room type air conditioner having a plurality of indoor units, since an electronic expansion valve is opened at a minute opening preventing a refrigerant from being collected inside a heat exchanger and the refrigerant is made slightly flow to indoor heat exchangers during stop of heating operation (when a thermostat is turned off), the air conditioner detects the temperature higher than room temperature to be normally detected due to increase in ambient temperature in the vicinity of the indoor units caused by radiation heat from the indoor units and due to short circuit etc. and thus the temperature of a lower part of a room where a user is located does not reach set temperature to turn on the thermostat although the room temperature is lowered, which makes the user uncomfortable because heating operation is not performed. <P>SOLUTION: Predetermined set temperature for stopping heating operation (thermostat off point) and predetermined set temperature for starting heating operation (thermostat on point) are discriminated. By appropriately shifting the set temperature, early turning-off and delayed turning-on of the heating operation can be prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multi-room air conditioner having a plurality of indoor units, and more specifically, the judgment when turning on the thermo from the heating thermo OFF and the judgment when turning off the thermo from the heating thermo ON are optimized. The present invention relates to the control of a multi-room air conditioner.

Conventionally, in a multi-room air conditioner having a plurality of indoor units, the electronic expansion valve is fully closed when the temperature reaches an arbitrarily set temperature after the heating operation is performed and the operation is stopped (thermo OFF). Instead, the refrigerant is opened at a very small opening so that the refrigerant does not accumulate inside the heat exchanger of the indoor unit, and the refrigerant is allowed to flow through the indoor heat exchanger. Further, while the heating operation is stopped, the room temperature is measured while the air blowing operation is performed in order to detect the intake air temperature in order to make a determination to start the next heating operation. The blowing operation at this time is an operation as a stop machine, and there is a possibility of giving the user a feeling of cold air, so it is performed intermittently, and the air volume is set at a low speed setting (for example, Patent Document 1).
JP 2004-144377 A

  However, in the above-described conventional configuration, in the indoor unit in which the heating operation is stopped, the ambient temperature rise around the indoor unit due to the radiant heat from the indoor heat exchanger due to the slightly flowing refrigerant, and particularly the ceiling-embedded indoor unit , The temperature rise due to warm air accumulated near the ceiling, and when the air blowing operation during detection is low speed operation, the wind on the blowout side will flow directly to the suction side (short circuit) phenomenon, which should be detected originally Since the temperature higher than the room temperature is detected, the room temperature is lowered in the lower part of the user's room, but the temperature set by the user does not reach the thermo-ON temperature, and the heating operation is not started, so the user feels uncomfortable. Could give.

  Also, even in indoor units that perform heating operation, room temperature is lower at the lower part of the room where the user is located because the lower temperature of the indoor fan detects a temperature higher than the room temperature that should be detected due to the same effect. However, it is determined that the room temperature has risen until the thermo-off value is reached, but the heating operation is stopped, which may cause discomfort to the user.

  The present invention solves the above-mentioned conventional problem, and makes an indoor unit recognize the difference between the intake air temperature at the time of heating operation and when the operation is stopped and the set temperature of the user, which are different in the situation of detecting the intake air temperature, Providing a multi-room air conditioner that can optimize the judgment when the thermo is turned ON or OFF from the thermo OFF or ON state, and improves the comfort of air conditioning by suppressing the early or late heating operation. The purpose is to do.

  In order to solve the above-described conventional problems, the present invention includes a plurality of indoor units including a ceiling embedded indoor unit. A certain indoor unit performs a heating operation, and the ceiling embedded indoor unit stops the operation. In the multi-room air conditioner that measures the room temperature while intermittently performing the air blowing operation, a predetermined set temperature (thermo OFF point) for stopping the heating operation and a predetermined set temperature for starting the heating operation ( And control means for shifting either the thermo-ON point or the thermo-OFF point or both of them by a predetermined value under a predetermined condition.

  Whether or not the heating operation is started or stopped by recognizing the appropriate thermo ON point and thermo OFF point from the indoor suction temperature when heating is stopped, regardless of the installation state of the ceiling embedded indoor unit and the user's setting status. Since it can be determined whether or not, the comfort of the user can be enhanced.

  Moreover, it has a control means which shifts the predetermined setting temperature (thermo OFF point) which stops heating operation with the air volume set by the user with a remote controller or the like.

  As a result, even when the user's air volume setting is low-speed operation, it is possible to recognize whether or not to stop the heating operation by recognizing an appropriate thermo OFF point from the indoor suction temperature during the heating operation. Can increase the sex.

  In addition, a storage unit is provided for storing the ratio of the shift at the start of the previous heating operation. Based on the stored shift amount, the heating operation is stopped based on the stored shift amount after the next heating operation is started. Control means for shifting the set temperature (thermo OFF point) is provided.

  As a result, under any installation conditions, the effect on the indoor suction temperature can be utilized during the next heating operation. Whether or not to stop the heating operation by recognizing an appropriate thermo OFF point from the indoor suction temperature during the heating operation. Therefore, the user's comfort can be improved.

  The present invention separates a predetermined set temperature (thermo OFF point) for stopping the heating operation and a predetermined set temperature (thermo ON point) for starting the heating operation, thereby differently detecting the intake air temperature during the heating operation. The indoor unit recognizes the difference between the intake air temperature at the time of stoppage and the user's set temperature, and the judgment when turning on the thermo from the heating thermo OFF state can be optimized, thereby improving the comfort of air conditioning Can do.

  In addition, even when the user's air volume setting is low-speed operation during heating operation, it is possible to recognize an appropriate thermo OFF point from the indoor suction temperature during heating operation and determine whether to stop the heating operation. Can enhance the comfort.

  Further, the ratio of the shift at the start of the previous heating operation is stored, and after the next heating operation is started, the predetermined set temperature (thermo OFF point) for stopping the heating operation is shifted based on the stored shift amount, thereby reducing the speed. The difference in the intake air temperature during operation can be recognized by the indoor unit, so that the heating operation can be prevented from being quickly cut off, and the comfort of air conditioning can be further improved.

  In particular, the temperature rises due to warm air accumulated near the ceiling, and further, when the air blowing operation at the time of detection is low speed operation, the wind on the blow-out side goes directly to the suction side (short circuit) phenomenon occurs, which is originally detected In a ceiling-embedded indoor unit that is likely to detect a temperature higher than the room temperature, it is effective to shift the set temperature, and the comfort can be enhanced in accordance with the user's feeling.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a multi-room air conditioner according to the present invention, in which a plurality of indoor units 4a and 4b (two in FIG. 1) are connected to one outdoor unit 2 by refrigerant piping. The outdoor unit 2 is provided with a compressor 6, a four-way valve 8, an outdoor heat exchanger 10, and an outdoor expansion valve 12 that are sequentially connected by refrigerant piping, while each indoor unit 4 a, 4 b has refrigerant piping. The indoor heat exchangers 14 a and 14 b and the indoor expansion valves 16 a and 16 b that are sequentially connected to each other are provided, and the plurality of indoor units 4 a and 4 b are connected in parallel to the outdoor unit 2.

  The outdoor unit 2 is provided with an outdoor fan 18 that sends air to the outdoor heat exchanger 10, and the indoor units 4a and 4b have indoor fans 26a and 26b that send air to the indoor heat exchangers 14a and 14b. And indoor heat exchanger temperature detection means 28a, 28b for detecting the refrigerant evaporation temperature of the indoor heat exchangers 14a, 14b during cooling or dehumidifying operation or the refrigerant condensation temperature of the indoor heat exchangers 14a, 14b during heating operation, Indoor temperature detecting means 30a and 30b for detecting the indoor temperature sucked into the indoor fans 26a and 26b are provided.

  In the multi-room air conditioner according to the present invention having the above-described configuration, the four-way valve 8 is switched so that the refrigerant discharged from the compressor 6 is sent to the indoor units 4a and 4b through the outdoor unit 2 during the cooling or dehumidifying operation. It is done.

  In the heating operation, the four-way valve is switched so that the refrigerant discharged from the compressor 6 is sent to the outdoor unit 2 through the indoor units 4a and 4b. At this time, the indoor expansion valves 16a and 16b mounted on the indoor units 4a and 4b are fully opened, and the throttle mechanism on the refrigeration cycle is the outdoor expansion valve 12. Form a refrigeration cycle.

  When the heating operation is performed as a whole multi-room air conditioner and a certain indoor unit is stopped, for example, the outdoor unit 2 is performing the heating operation, the indoor unit 4a is stopped, and the indoor unit 4b is stopped. When the heating operation is performed, the indoor fan 26a is stopped, but the indoor expansion valve 16a is slightly opened to ensure a small refrigerant flow rate so that the refrigerant does not accumulate in the indoor heat exchanger 14a. It is narrowed down to.

  Next, when the heating operation is performed as the entire multi-room air conditioner according to the first embodiment of the present invention and the indoor unit 4a is stopped, the indoor unit 4a detects the suction temperature. The operation will be described with reference to the flowchart of FIG. In addition, although the indoor unit 4a is demonstrated below, when the same selection is made in the indoor unit 4b or other indoor units when three or more indoor units (not shown) are connected, the same control is performed. Is done.

  First, after performing a standby operation for a predetermined time in order to intermittently measure the indoor suction temperature when the thermo is OFF (step S1), the indoor fan 26a is operated at a low speed operation to measure the indoor suction temperature, thereby detecting the indoor temperature. Temperature measurement is performed by means 30a (step S2). Next, it is determined whether the type of the indoor unit is a ceiling-embedded type (step S3). In the case of a ceiling-embedded indoor unit, warm air tends to accumulate near the ceiling. It is added to a set temperature (hereinafter referred to as a thermo ON point) set by a normal user (the added temperature is also referred to as a thermo ON point) (step S4). Then, it is determined whether or not the heating operation is started based on whether the suction temperature is lower than the thermo-ON point (step S5). If the temperature falls below the thermo-ON point, the indoor unit 4a determines that the heating operation needs to be started, opens the indoor expansion valve 16a, operates the indoor fan 26a at a speed commensurate with the load, and supplies warm air to the room (step S6). The indoor fan 26a operates only for a predetermined time, but if the temperature does not fall below the thermo-ON point during that time, the heating operation is not started and the air blowing operation is stopped (step S7). Thereafter, the flow returns to step S1 and the above control is performed. repeat.

As a result, even in the indoor suction temperature measurement at low speed operation in the indoor unit, it is possible to determine whether or not to start the heating operation based on the thermo-ON point considering the effect of warm air accumulation near the ceiling. Air conditioning can be performed without causing discomfort to the user at the bottom.

  In addition, although a flowchart is not shown for stopping the operation at the thermo OFF point of the heating operation, the warm air near the ceiling is increased by adding a predetermined value to the thermo OFF point in comparison with the indoor suction temperature measured during the heating operation. By determining whether or not to stop the heating operation based on the thermo OFF point in consideration of the effect of accumulation, air conditioning can be performed without causing discomfort to the user in the lower part of the living room.

  In particular, in a ceiling-embedded indoor unit, the temperature rises due to warm air that accumulates near the ceiling, and when the air blowing operation during detection is performed at low speed, the blowout side wind flows directly into the suction side (short circuit). Therefore, it is highly possible to detect a temperature higher than the room temperature that should be detected, so it is effective to add a predetermined value to the thermo-ON point or thermo-OFF point. The capacity rank varies depending on the type of indoor unit, and there is a difference in the radiant heat from the indoor heat exchanger 14a due to the slight opening of the indoor expansion valve 16a. As a result, there is a difference in the influence on the indoor temperature detection means 30a. Therefore, it is preferable to set a value experimentally determined for each indoor unit in consideration of versatility.

(Embodiment 2)
Next, the operation when the indoor unit detects the suction temperature during the heating operation according to the second embodiment of the present invention will be described with reference to the flowchart of FIG. In addition, although the indoor unit 4a is demonstrated below, the same control is performed also when the same selection is made in the indoor unit 4b or other indoor units not shown.

  Since the heating operation is being performed and the indoor fan operation for measuring the indoor suction temperature is also performed, first, the temperature is measured by the indoor temperature detection means 30a (step S1). Next, the type of the own indoor unit is determined (step S2). Next, the user's air volume setting is recognized (step S3). If the own indoor unit is not a ceiling-embedded type or other than a low-speed setting, heating is stopped based on a predetermined value (thermo OFF point) in which the difference between the suction temperature and the set temperature set by the user is determined in advance. Judgment and heating operation is stopped if the temperature exceeds the thermo-off point, but if it is a low-speed setting for a ceiling-embedded indoor unit, only a predetermined value will be taken in consideration of the accumulation of warm air near the ceiling and the effect of a short circuit. A value is added to the normal thermo OFF point (step S4), and it is determined whether or not to stop the heating operation (step S5). If the temperature exceeds the thermo OFF point to which a predetermined value has been added, 4a determines that the heating operation needs to be stopped, closes indoor expansion valve 16a until it is slightly opened, stops indoor fan 26a, and stops the supply of warm air (step S6). ). If the state of being below the thermo OFF point to which the predetermined value is added continues, the process returns to step S1 and the above control is repeated.

  This makes it possible to determine whether or not to stop the heating operation based on the thermo OFF point considering the influence of a short circuit, particularly in the indoor suction temperature measurement at low speed operation in the ceiling-embedded indoor unit. Can be prevented, and air conditioning can be performed without causing discomfort to the user in the lower part of the living room.

  In addition, the value added from the thermo-OFF point varies depending on the similar ceiling-embedded indoor unit, and the radiant heat from the indoor heat exchanger 14a during the heating operation varies. As a result, there is a difference in the influence on the indoor temperature detection means 30a. Therefore, it is preferable to set a value experimentally determined for each indoor unit in consideration of versatility.

(Embodiment 3)
Next, the operation when the indoor unit detects the suction temperature in the state where the heating operation is performed as the whole multi-room air conditioner and the certain indoor unit is stopped according to the third embodiment of the present invention. Will be described with reference to the flowchart of FIG. In addition, although the indoor unit 4a is demonstrated below, when the same selection is made in 4b and the other indoor unit which is not illustrated, the same control is performed.

  First, after performing a standby operation for a predetermined time in order to measure temperature intermittently (step S1), the indoor fan 26a is operated at a low speed operation to measure the indoor suction temperature, and the temperature is measured by the indoor temperature detecting means 30a. (Step S2). Next, the temperature of the indoor heat exchanger is measured by the indoor heat exchanger temperature detecting means 28a in order to calculate the influence on the indoor temperature detecting means 30a due to the temperature rise around the indoor unit due to radiant heat (step S3). At this time, it is determined whether the indoor heat exchanger temperature exceeds a predetermined temperature (step S4), and if it exceeds, a predetermined temperature is determined based on the difference between the predetermined temperature and the current indoor heat exchanger temperature. The coefficient is multiplied to determine the shift amount from the normal thermo ON point (step S5). Then, this shift amount is added to the normal thermo-ON point (step 6), and it is determined whether or not the heating operation is started based on this value (step S7). When the suction temperature is smaller than the value obtained by adding this shift amount to the normal thermo ON point, it is determined that the heating operation needs to be started, the indoor expansion valve 16a is opened, and the indoor fan 26a is operated at a speed commensurate with the load. Then, warm air is supplied into the room (step S8). The indoor fan 26a operates only for a predetermined time, but if the temperature does not fall below the thermo-ON point during that time, the heating operation is not started and the air blowing operation is stopped (step S9). repeat.

  As a result, in a multi-room air conditioner with different loads in each room, heating is performed by a thermo-ON point that takes into account the effect on the indoor suction temperature due to excessive heat exchanger temperature rise due to the influence of other indoor units. It can be determined whether or not to start driving, and air conditioning can be performed without causing discomfort to the user in the lower part of the living room.

(Embodiment 4)
Next, the operation when the indoor unit detects the suction temperature in the state where the heating operation is performed as the whole multi-room air conditioner and the certain indoor unit is stopped according to the fourth embodiment of the present invention. Will be described with reference to the flowchart of FIG. Note that the above-described contents will be omitted.

  First, after performing a standby operation for a predetermined time in order to measure temperature intermittently (step S1), the indoor fan 26a is operated at a low speed operation to measure the indoor suction temperature, and the temperature is measured by the indoor temperature detecting means 30a. (Step S2). Next, the indoor unit is caused to recognize the current installation height by means for setting the height from the floor surface in the living room to the indoor unit (step S3).

  At this time, it is determined whether the height from the floor surface of the living room to the indoor unit 4a exceeds a predetermined height (step S4), and if it exceeds, the current installation height and a predetermined predetermined height are determined. The shift amount from the normal thermo-ON point is determined by multiplying a predetermined coefficient based on the difference between the temperature and the temperature (step S5). Thereafter, Steps 6 to 9 are performed similarly to the third embodiment, and when the heating operation is not started, the process returns to Step S1 and the above control is repeated.

  As a result, even in indoor units where the room space is large, the difference between the ambient temperature in the lower part of the room and the ceiling is easy to open, and the air volume from the ceiling is difficult to reach, heating operation is performed with the thermo ON point taking this effect into account. It can be determined whether or not to start, and air conditioning can be performed without causing discomfort to the user in the lower part of the living room.

(Embodiment 5)
Next, the operation when the indoor unit detects the suction temperature in the state where the heating operation is performed as the whole multi-room air conditioner and the certain indoor unit is stopped according to the fifth embodiment of the present invention. Will be described with reference to the flowchart of FIG. Note that the above-described contents will be omitted.

  First, in the same manner as in the third and fourth embodiments, the amount shifted from the normal thermo-ON point, which was determined when the thermo was turned on last time, is stored (step S1). Next, after the thermo-ON and the heating operation are started, the temperature is measured by the room temperature detecting means 30a as in the second embodiment (step S2). Then, based on the thermo-off point shift amount determined at the time of the previous operation stop, a value is added to the normal thermo-off point by a predetermined value (step S3), and it is determined whether or not to stop the heating operation (step S4). If the temperature exceeds the thermo OFF point to which a predetermined value is added, the indoor unit 4a determines that the heating operation needs to be stopped, closes the indoor expansion valve 16a until it is slightly opened, stops the indoor fan 26a, and stops the supply of warm air ( Step S5). If the state of being below the thermo OFF point to which the predetermined value is added continues, the process returns to step S2 and the above control is repeated.

  As a result, by using the thermo-ON point shift amount determined during the previous operation stop as the thermo-OFF point shift amount, even if there are variations in various usage conditions, the thermo-off point considering the latest ambient temperature state Whether or not to stop the heating operation can be determined to prevent the heating operation from being quickly cut off, and air conditioning can be performed without causing discomfort to the user in the lower part of the living room.

  The control of a multi-room air conditioner that optimizes the judgment when turning on the thermo from the heating thermo OFF and the judgment when turning off the thermo from the heating thermo ON is not limited to the ceiling-embedded indoor unit. The installed indoor units have the same tendency and can be applied, of course, not only on the ceiling, but when the intake air temperature differs from the actual room temperature depending on the installation conditions, the measured temperature is adjusted accordingly. It is useful to shift

The block diagram in the 1st Embodiment of this invention The flowchart in the 1st Embodiment of this invention Flowchart in the second embodiment of the present invention Flowchart in the third embodiment of the present invention Flowchart in the fourth embodiment of the present invention Flowchart in the fifth embodiment of the present invention

Explanation of symbols

2 Outdoor unit 4a, 4b Indoor unit 6 Compressor 8 Four-way valve 10 Outdoor heat exchanger 12 Outdoor expansion valve 14a, 14b Indoor heat exchanger 16a, 16b Indoor expansion valve 18 Outdoor fan 26a, 26b Indoor fan 28a, 28b Indoor heat exchange Temperature detection means 30a, 30b Indoor temperature detection means

Claims (6)

When multiple indoor units are installed, heating operation is performed in one indoor unit and operation is stopped in other indoor units, the indoor unit that is stopped In the multi-room air conditioner to be measured, a predetermined set temperature (thermo OFF point) for stopping the heating operation is distinguished from a predetermined set temperature (thermo ON point) for starting the heating operation, and the predetermined heating temperature is started. A control unit that shifts either the set temperature (thermo ON point) of the heater or the predetermined set temperature (thermo OFF point) for stopping the heating operation, or both of them by a predetermined value. Air conditioner. 2. The multi-room air conditioner according to claim 1, further comprising a control unit that shifts a predetermined set temperature (thermo OFF point) at which the heating operation is stopped according to an air volume set by a user using a remote controller or the like. A means for detecting the temperature of the heat exchanger in the room is provided, the influence on the suction temperature is calculated from the detected temperature of the heat exchanger according to a predetermined calculation formula, and the difference is set to a predetermined set temperature for starting the heating operation ( The multi-room air conditioner according to claim 1 or 2, further comprising control means for changing a ratio of shifting from the thermo ON point. A means for setting the height from the floor surface in the living room to the indoor unit is provided, and the ratio of shifting the predetermined set temperature (thermo ON point) for starting the heating operation is changed according to the ceiling height set by this means. The multi-room air conditioner according to any one of claims 1 to 3, further comprising a control unit that controls the multi-room air conditioner. A storage means is provided for storing the ratio of the shift at the start of the previous heating operation, and after the next heating operation starts, a predetermined set temperature (thermo OFF point) for stopping the heating operation is shifted based on the stored shift amount. It has a control means, The multi-room air conditioner as described in any one of Claims 1-4 characterized by the above-mentioned. 6. The indoor unit that includes a ceiling-embedded indoor unit among a plurality of indoor units and that has stopped operation is the ceiling-embedded indoor unit. 6. Multi-room air conditioner.