JP7215145B2 - air conditioner - Google Patents

Description

The present invention relates to an air conditioner in which a plurality of indoor units are connected to an outdoor unit.

In an air conditioner in which multiple indoor units are connected to an outdoor unit, the evaporating temperature in the indoor heat exchanger of each indoor unit that functions as an evaporator during cooling operation is set to a predetermined target value (hereinafter referred to as the target evaporating temperature). Also, during heating operation, the condensation temperature in the indoor heat exchanger of each indoor unit that functions as a condenser is a predetermined target value (hereinafter referred to as the target condensation temperature) that is different from that during cooling operation. There is one in which the rotation speed of the compressor is controlled so as to be (for example, Patent Document 1). Here, the target evaporating temperature and the target condensing temperature are the evaporating temperature and the condensing temperature required for the indoor unit to exhibit the rated capacity, which is the maximum value of the air conditioning capacity exhibited by the indoor unit. In the air conditioner of Patent Document 1, the target evaporation temperature and the target condensation temperature are not changed even when the air conditioning capacity required by each indoor unit is all smaller than the rated capacity, and the evaporation temperature and the condensation temperature are always the target. The rotation speed of the compressor is controlled so as to achieve the evaporation temperature and the target condensation temperature. For this reason, in the air conditioner of Patent Document 1, there is a problem that the compressor is driven at an unnecessarily high rotational speed, resulting in deterioration of energy saving performance.

On the other hand, during cooling operation and heating operation, the target evaporating temperature and An air conditioner in which a target condensing temperature is determined has been proposed (for example, Patent Document 2). In the air conditioner described in Patent Literature 2, during cooling operation, if the air conditioning capacity required by each indoor unit is smaller than the rated capacity, the target evaporation temperature is higher than the rated capacity. Further, during heating operation, if the air conditioning capacity required for each indoor unit is smaller than the rated capacity, the temperature of the target condensing capacity is lower than the rated capacity. Then, the rotational speed of the compressor is controlled so that the evaporation temperature and the condensation temperature reach the target evaporation temperature and the target condensation temperature. Therefore, unlike the air conditioner of Patent Document 1, the compressor is not driven at an unnecessarily high rotational speed, and the power consumption of the air conditioner is suppressed, thereby improving energy saving.

JP-A-2-230063 JP 2014-238179

By the way, when a plurality of indoor units are installed in one room, some of the indoor units are placed in a place where the air conditioning load is temporarily larger than that of the other indoor units, such as near a window. It may be installed near the entrance/exit. The indoor temperature detected by an indoor unit installed near a window may be higher than the indoor temperature detected by other indoor units due to sunlight in the summer, and may be detected by other indoor units due to the cold air coming through the windows in the winter. It may be lower than room temperature. In addition, the indoor temperature detected by the indoor unit installed near the doorway may be higher than the indoor temperature detected by other indoor units in the summer due to the inflow of outside air due to the opening and closing of the door. The indoor temperature may be lower than that detected by the indoor unit.

For indoor units installed near windows or doorways, even if the set temperature is almost the same as that of other indoor units, the detected room temperature may be higher than the room temperature detected by other indoor units for the reasons described above. or lower. As a result, the temperature difference between the set temperature and the indoor temperature becomes the largest among all the temperature differences among all indoor units. It may be the maximum required capacity among the air conditioning capacity required by .

However, the indoor temperature detected by the above-mentioned indoor units installed near windows and doorways is often affected only temporarily. That is, in many cases, the air conditioning capacity that the indoor unit requires of the outdoor unit becomes the maximum required capacity only temporarily. In such an air conditioner having multiple indoor units, including indoor units installed near windows and doorways, the target evaporating temperature and target condensing temperature are determined, and if the compressor rotation speed is controlled to achieve these target evaporating temperature and target condensing temperature, changes in indoor temperature detected by indoor units installed near windows and doorways will temporarily Although it is not necessary to respond to the maximum required capacity due to a temporary change in room temperature, this maximum is reached every time the maximum required capacity is reached due to a temporary change in room temperature Since the rotation speed of the compressor is increased so as to exhibit the required capacity, there is a possibility that the energy-saving performance of the air conditioner may be lowered.

An object of the present invention is to solve the above-described problems, and to provide an air conditioner capable of improving energy saving performance when controlling the rotation speed of the compressor according to the air conditioning capacity required by each indoor unit. With the goal.

In order to solve the above problems, the air conditioner of the present invention provides an outdoor unit having a compressor, a plurality of indoor units having indoor temperature detection means for detecting the indoor temperature, and driving control of the compressor. and control means. The control means acquires from each indoor unit the indoor temperature detected by the indoor temperature detection means and the set temperature, which is the target temperature for air conditioning operation set in each indoor unit, and calculates the indoor temperature from the set temperature for each indoor unit. The maximum required capacity is found based on the largest maximum temperature difference among the absolute values of the temperature differences, and the compressor is controlled at the rotational speed at which the maximum required capacity can be exhibited. Then, if the condition for ignoring the required capacity is satisfied during the air conditioning operation, the control of the compressor is not changed. Here, the condition for ignoring the required capacity is that the number of indoor units with the maximum temperature difference is one, and the average value of the temperature differences of all the indoor units other than the indoor unit with the maximum temperature difference is the maximum Assume that the temperature difference is greater than a predetermined value.

In the air conditioner of the present invention as described above, if the condition for ignoring the required capacity is satisfied during air conditioning operation, the control of the compressor is not changed. As a result, it is possible to improve energy saving when controlling the rotation speed of the compressor according to the air conditioning capacity required by each indoor unit.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the air conditioning apparatus in embodiment of this invention, (A) is a refrigerant circuit diagram, (B) is a block diagram of an outdoor unit control means. It is an indoor unit operating state table in the embodiment of the present invention. Fig. 4 is a flow chart showing processing for determining the air conditioning capacity required by each indoor unit in the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. As an embodiment, an air conditioner in which ten indoor units are connected in parallel to an outdoor unit and all of the indoor units can perform cooling operation or heating operation at the same time will be described as an example. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present invention.

As shown in FIG. 1A, the air conditioner 1 in this embodiment includes one outdoor unit 2 and ten indoor units connected in parallel to the outdoor unit 2 via liquid pipes 8 and gas pipes 9. 5-1 to 5-10 (only two of them are drawn in FIG. 1(A)). More specifically, the closing valve 25 of the outdoor unit 2 and the liquid pipe connection portion 53 of each indoor unit 5 are connected by the liquid pipe 8 . Also, the closing valve 26 of the outdoor unit 2 and the gas pipe connection portion 54 of each indoor unit 5 are connected by the gas pipe 9 . Thus, the outdoor unit 2 and the ten indoor units 5 are connected by the liquid pipes 8 and the gas pipes 9 to form the refrigerant circuit 10 of the air conditioner 1 .

<Configuration of outdoor unit>
First, the outdoor unit 2 will be explained. The outdoor unit 2 includes a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, an outdoor unit expansion valve 24, a closing valve 25 to which the liquid pipe 8 is connected, and a closing valve to which the gas pipe 9 is connected. 26 , an accumulator 27 , an outdoor unit fan 28 , and an outdoor unit control means 200 . These devices except for the outdoor unit fan 28 and the outdoor unit control means 200 are connected to each other by refrigerant pipes described in detail below to form an outdoor unit refrigerant circuit 20 forming a part of the refrigerant circuit 10. ing.

The compressor 21 is a variable capacity compressor that can vary its operating capacity by being driven by a motor (not shown) whose rotational speed is controlled by an inverter. A refrigerant discharge side of the compressor 21 is connected to a port a of the four-way valve 22 to be described later by a discharge pipe 41 . The refrigerant suction side of the compressor 21 is connected to the refrigerant outflow side of the accumulator 27 by a suction pipe 42 .

The four-way valve 22 is a valve for switching the direction of refrigerant flow in the refrigerant circuit 10, and has four ports a, b, c, and d. The port a is connected to the refrigerant discharge side of the compressor 21 by the discharge pipe 41 as described above. The port b is connected to one refrigerant inlet/outlet of the outdoor heat exchanger 23 by a refrigerant pipe 43 . The port c is connected to the refrigerant inflow side of the accumulator 27 by a refrigerant pipe 46 . The port d is connected to the closing valve 26 and the outdoor unit gas pipe 45 .

The outdoor heat exchanger 23 exchanges heat between the refrigerant and outside air taken into the outdoor unit 2 by the rotation of the outdoor unit fan 28, which will be described later. As described above, one refrigerant inlet/outlet of the outdoor heat exchanger 23 and the port b of the four-way valve 22 are connected by the refrigerant pipe 43 . The other refrigerant inlet/outlet of the outdoor heat exchanger 23 and the closing valve 25 are connected by an outdoor unit liquid pipe 44 . The outdoor heat exchanger 23 functions as a condenser when the air conditioner 1 performs cooling operation, and functions as an evaporator when the air conditioner 1 performs heating operation.

The outdoor unit expansion valve 24 is provided in the outdoor unit liquid pipe 44 . The outdoor unit expansion valve 24 is an electronic expansion valve driven by a pulse motor (not shown). , the amount of refrigerant flowing out of the outdoor heat exchanger 23 is adjusted. The degree of opening of the outdoor unit expansion valve 24 is set so that the degree of superheating of the refrigerant on the refrigerant outlet side of the outdoor heat exchanger reaches the target degree of superheating of the refrigerant, which will be described later, when the air conditioner 1 is performing heating operation. is adjusted. Further, the degree of opening of the outdoor unit expansion valve 24 is fully opened during cooling operation.

As described above, the accumulator 27 is connected to the port c of the four-way valve 22 by the refrigerant pipe 46 on the refrigerant inflow side, and is connected to the refrigerant suction side of the compressor 21 by the suction pipe 42 on the refrigerant outflow side. The accumulator 27 separates the refrigerant that has flowed into the accumulator 28 from the refrigerant pipe 46 into gas refrigerant and liquid refrigerant, and causes the compressor 21 to suck only the gas refrigerant.

The outdoor unit fan 28 is made of a resin material and arranged near the outdoor heat exchanger 23 . The outdoor unit fan 28 is rotated by a fan motor (not shown) to draw outside air into the outdoor unit 2 from a suction port (not shown), and the outside air heat-exchanged with the refrigerant in the outdoor heat exchanger 23 is discharged from an outlet (not shown) to the outside of the room. Discharge to the outside of machine 2.

In addition to the configuration described above, the outdoor unit 2 is provided with various sensors. As shown in FIG. 1A, a discharge pipe 41 is provided with a discharge pressure sensor 31 for detecting the pressure of the refrigerant discharged from the compressor 21 and a temperature sensor for detecting the temperature of the refrigerant discharged from the compressor 21. A discharge temperature sensor 33 is provided for detection. A suction pressure sensor 32 for detecting the suction pressure, which is the pressure of the refrigerant sucked into the compressor 21, and the temperature of the refrigerant sucked into the compressor 21 are provided near the refrigerant inlet of the accumulator 28 in the refrigerant pipe 46. A suction temperature sensor 34 is provided.

Between the outdoor heat exchanger 23 and the outdoor unit expansion valve 24 in the outdoor unit liquid pipe 44, the temperature of the refrigerant flowing into the outdoor heat exchanger 23 or the temperature of the refrigerant flowing out of the outdoor heat exchanger 23 is detected. A heat exchanger temperature sensor 35 is provided for this purpose. An outside air temperature sensor 36 for detecting the temperature of the outside air flowing into the inside of the outdoor unit 2, ie, the outside air temperature, is provided near the suction port (not shown) of the outdoor unit 2 .

Further, the outdoor unit 2 is provided with outdoor unit control means 200 which is the control means of the present invention. The outdoor unit control means 200 is mounted on a control board housed in an electrical component box (not shown) of the outdoor unit 2, and as shown in FIG. , and a sensor input unit 240 .

The storage unit 220 is, for example, a flash memory, and stores a control program for the outdoor unit 2, detection values corresponding to detection signals from various sensors, driving states of the compressor 21 and the outdoor unit fan 28, and information transmitted from each indoor unit 5. It stores operation information (including operation/stop information, operation modes such as cooling/heating), the rated capacity of the outdoor unit 2, and the required capacity of each indoor unit 5. The communication unit 230 is an interface that communicates with each indoor unit 5 . The sensor input unit 240 takes in detection results from various sensors of the outdoor unit 2 and outputs them to the CPU 210 .

The CPU 210 periodically (for example, every 30 seconds) takes in values detected by various sensors via the sensor input unit 240, and receives signals including operation information transmitted from each indoor unit 5 via the communication unit 230. is entered. The CPU 210 adjusts the degree of opening of the outdoor unit expansion valve 24 and controls the driving of the compressor 21 and the outdoor unit fan 28 based on the input various information.

<Configuration of each indoor unit>
Next, ten indoor units 5-1 to 5-10 will be described. The ten indoor units 5-1 to 5-10 all have the same configuration, and include an indoor heat exchanger 51, an indoor unit expansion valve 52, a liquid pipe connection portion 53, a gas pipe connection portion 54, An indoor unit fan 55 is provided. These constituent devices except for the indoor unit fan 55 are connected to each other by refrigerant pipes described in detail below to form the indoor unit refrigerant circuit 50 forming a part of the refrigerant circuit 10 .

The indoor heat exchanger 51 exchanges heat between the refrigerant and the indoor air taken into the indoor unit 5 from a suction port (not shown) by the rotation of the indoor unit fan 55, which will be described later. One refrigerant inlet/outlet of the indoor heat exchanger 51 and the liquid pipe connection portion 53 are connected by the indoor unit liquid pipe 71 , and the other refrigerant inlet/outlet and the gas pipe connection portion 54 a are connected by the indoor unit gas pipe 72 . The indoor heat exchanger 51 functions as an evaporator when the air conditioner 1 performs cooling operation, and functions as a condenser when the air conditioner 1 performs heating operation. The refrigerant pipes are connected to the liquid pipe connection portion 53 and the gas pipe connection portion 54 by welding, flare nuts, or the like.

The indoor unit expansion valve 52 is provided in the indoor unit liquid pipe 71 . The indoor unit expansion valve 52 is an electronic expansion valve, and when the indoor heat exchanger 51 functions as an evaporator, that is, when the indoor unit 5 performs cooling operation, the degree of opening of the indoor unit expansion valve 52 is determined by the refrigerant outlet of the indoor heat exchanger 51 ( The degree of superheating of the refrigerant at the gas pipe connecting portion 54 side) is adjusted to the target degree of superheating of the refrigerant. Further, when the indoor heat exchanger 51 functions as a condenser, that is, when the indoor unit 5 performs heating operation, the degree of opening of the indoor unit expansion valve 52 is determined by the refrigerant outlet (liquid pipe connection) of the indoor heat exchanger 51. 53 side) is adjusted to the target refrigerant subcooling degree. Here, the target refrigerant superheating degree and the refrigerant subcooling degree are the refrigerant superheating degree and the refrigerant subcooling degree necessary for exhibiting sufficient cooling capacity or heating capacity in each of the indoor units 5-1 to 5-10. is.

The indoor unit fan 55 is made of a resin material and arranged near the indoor heat exchanger 51 . The indoor unit fan 55 is rotated by a fan motor (not shown) to take indoor air into the interior of the indoor unit 5 from a suction port (not shown), and the indoor air heat-exchanged with the refrigerant in the indoor heat exchanger 51 is discharged from an outlet (not shown). released into the room from

In addition to the configuration described above, the indoor unit 5 is provided with various sensors. Between the indoor heat exchanger 51 and the indoor unit expansion valve 52 in the indoor unit liquid pipe 71, a liquid side temperature sensor 61 for detecting the temperature of the refrigerant flowing into or out of the indoor heat exchanger 51 is provided. is provided. The indoor unit gas pipe 72 is provided with a gas-side temperature sensor 62 that detects the temperature of the refrigerant flowing out of or flowing into the indoor heat exchanger 51 . An indoor temperature sensor 63 that detects the temperature of indoor air flowing into the indoor unit 5 is provided near the suction port (not shown) of the indoor unit 5 .

<Operation of refrigerant circuit>
Next, the flow of the refrigerant in the refrigerant circuit 10 and the operation of each part during the air conditioning operation of the air conditioner 1 according to the present embodiment will be described with reference to FIG. 1(A). In the following description, the case where the air conditioner 1 performs the heating operation will be described first, and then the case where the air conditioner 1 performs the cooling operation will be described. The solid line arrows in FIG. 1A indicate the flow of refrigerant during heating operation. The dashed arrows in FIG. 1(A) indicate the flow of refrigerant during cooling operation.

<Heating operation>
As shown in FIG. 1, when the air conditioner 1 performs heating operation, the four-way valve 22 is in the state indicated by the solid line, that is, the port a and the port d of the four-way valve 22 are in communication, and the port b and port c are switched to communicate with each other. Thereby, the refrigerant circuit 10 becomes a heating cycle in which each indoor heat exchanger 51 functions as a condenser and the outdoor heat exchanger 23 functions as an evaporator.

When the compressor 21 is driven in a state where the refrigerant circuit 10 functions as a heating cycle, the refrigerant discharged from the compressor 21 flows through the discharge pipe 41, flows into the four-way valve 22, and flows from the four-way valve 22 to the outdoor unit gas pipe 45. and flows into the gas pipe 9 via the closing valve 26 .

Refrigerant flowing through the gas pipe 9 is branched to the indoor units 5-1 to 5-10 via each gas pipe connection portion . The refrigerant that has flowed into the indoor units 5 - 1 to 5 - 10 flows through each indoor unit gas pipe 72 and flows into each indoor heat exchanger 51 . The refrigerant that has flowed into each indoor heat exchanger 51 exchanges heat with the indoor air taken into each indoor unit 5 by the rotation of each indoor unit fan 55, and is condensed.

In this way, each indoor heat exchanger 51 functions as a condenser, and the indoor air heated by exchanging heat with the refrigerant in each indoor heat exchanger 51 is blown into the room from an outlet (not shown). The room in which the indoor units 5-1 to 5-10 are installed is heated.

The degree of opening of the refrigerant flowing from each indoor heat exchanger 51 into each indoor unit liquid pipe 71 is adjusted so that the degree of refrigerant supercooling at the refrigerant outlet side of each indoor heat exchanger 51 becomes the target degree of refrigerant supercooling. The pressure is reduced when passing through each indoor unit expansion valve 52 . Here, the target refrigerant subcooling degree is determined based on the heating capacity required in each of the indoor units 5-1 to 5-10. Further, the heating capacity is determined based on the temperature difference between the set temperature and the detected room temperature in each of the indoor units 5-1 to 5-10.

The refrigerant decompressed by each indoor unit expansion valve 52 flows out from each indoor unit liquid pipe 71 to the liquid pipe 8 via each liquid pipe connecting portion 53 . The refrigerant that joins the liquid pipe 8 and flows into the outdoor unit 2 through the closing valve 25 flows through the outdoor unit liquid pipe 44 so that the degree of superheat of the refrigerant at the refrigerant outlet side of the outdoor heat exchanger 23 becomes the target degree of superheat of the refrigerant. The pressure is further reduced when passing through the outdoor unit expansion valve 24 whose opening is adjusted to . Here, the target refrigerant degree of superheat is obtained by performing a test or the like in advance and stored in the storage unit 220 of the outdoor unit control means 200. The outdoor heat exchanger 23 that functions as an evaporator during heating operation If the degree of superheating of the refrigerant at the refrigerant outlet side of is set as the target degree of superheating of the refrigerant, it is a value that confirms that liquid backflow does not occur.

The refrigerant decompressed by the outdoor unit expansion valve 24 flows through the outdoor unit liquid pipe 44 and into the outdoor heat exchanger 23, and is taken into the outdoor unit 5 by the rotation of the outdoor unit fan 28, which is set to the maximum rotation speed. It evaporates by exchanging heat with the outside air. Refrigerant that has flowed from the outdoor heat exchanger 23 into the refrigerant pipe 43 flows through the four-way valve 22, the refrigerant pipe 46, the accumulator 27, and the suction pipe 42 in that order, is sucked into the compressor 21, and is compressed again.

<Cooling operation>
When the air conditioner 1 performs cooling operation, as shown in FIG. , port c and port d are switched to communicate with each other. Thereby, the refrigerant circuit 10 becomes a heating cycle in which each indoor heat exchanger 51 functions as an evaporator and the outdoor heat exchanger 23 functions as a condenser.

When the compressor 21 is driven while the refrigerant circuit 10 functions as a cooling cycle, the refrigerant discharged from the compressor 21 flows through the discharge pipe 41 into the four-way valve 22 and flows from the four-way valve 22 through the refrigerant pipe 43. and flows into the outdoor heat exchanger 23 . The refrigerant that has flowed into the outdoor heat exchanger 23 exchanges heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor unit fan 28, and is condensed. The refrigerant that has flowed out from the outdoor heat exchanger 23 to the outdoor unit liquid pipe 44 passes through the outdoor unit expansion valve 24 that is fully opened, and flows out to the liquid pipe 8 via the closing valve 25 .

Refrigerant flowing through the liquid pipe 8 flows into the indoor units 5-1 to 5-10 via the respective liquid pipe connection portions 53. As shown in FIG. The refrigerant flowing into the indoor units 5-1 to 5-10 flows through each indoor unit liquid pipe 71, and the degree of opening is adjusted so that the refrigerant superheat degree at each refrigerant outlet of each indoor heat exchanger 51 becomes the target refrigerant superheat degree. is decompressed when passing through each of the indoor unit expansion valves 52 in which is adjusted. Here, the target refrigerant superheat degree is determined based on the cooling capacity required for each of the indoor units 5-1 to 5-10. Also, the cooling capacity is determined based on the temperature difference between the set temperature and the detected room temperature in each of the indoor units 5-1 to 5-10.

The refrigerant flowing into each indoor heat exchanger 51 from each indoor unit liquid pipe 71 exchanges heat with the indoor air taken into the indoor units 5-1 to 5-10 by the rotation of each indoor unit fan 55. Evaporate. In this way, each indoor heat exchanger 51 functions as an evaporator, and the indoor air cooled by exchanging heat with the refrigerant in each indoor heat exchanger 51 is blown into the room from an outlet (not shown). The room in which the indoor units 5-1 to 5-10 are installed is cooled.

The refrigerant flowing out from each indoor heat exchanger 51 to each indoor unit gas pipe 72 flows out to gas pipe 9 via each gas pipe connecting portion 54 . The refrigerant that joins the gas pipe 9 and flows into the outdoor unit 2 through the closing valve 26 flows through the outdoor unit gas pipe 45, the four-way valve 22, the refrigerant pipe 46, the accumulator 27, and the suction pipe 42 in this order, and is sucked into the compressor 21. and compressed again.

<Compressor control according to the air conditioning capacity required by the indoor unit>
The air conditioner 1 of the present embodiment described so far has a set temperature (hereinafter referred to as set temperature A temperature difference (hereinafter referred to as a temperature difference ΔT) is calculated by subtracting the indoor temperature detected by the indoor temperature sensor 63 (hereinafter referred to as an indoor temperature Tr) from the temperature Tp). Then, the required capacity based on the largest temperature difference ΔT among the temperature differences ΔT, that is, the air conditioning capacity required by the indoor units 5-1 to 5-10 (heating capacity during heating operation/cooling capacity during cooling operation) capacity) is defined as the system required capacity, and the target evaporating temperature or the target condensing temperature is set based on this system required capacity, and the compressor 21 is controlled so that the target evaporating temperature or the target condensing temperature can be achieved. The number of revolutions is controlled. In this way, by controlling the rotation speed of the compressor 21 so as to achieve the target evaporation temperature or the target condensation temperature, the indoor unit with the maximum required capacity and the air conditioning capacity other than the indoor unit with the maximum required capacity The required amount of refrigerant is supplied to each indoor unit having a smaller capacity.

FIG. 2 shows the set temperature Tp set in each of the indoor units 5-1 to 5-10 and the indoor temperature Tr detected by the indoor temperature sensor 63 of each of the indoor units 5-1 to 5-10. 3 is an indoor unit operating state table 300 stored for each of the units 5-1 to 5-10. Note that FIG. 2 shows, as an example, the indoor unit operating state table 300 when the air conditioner 1 is performing heating operation. This indoor unit operating state table 300 is stored in the storage unit 220 of the outdoor unit control means 200 .

Specifically, the indoor unit operating state table 300 stores the numbers of the indoor units 5-1 to 5-10 (here, the indoor unit 5-1 is "1") for each of the indoor units 5-1 to 5-10. ), operation mode (here, all are "heating"), set temperature Tp (unit: ° C), indoor temperature Tr (unit: ° C), set temperature Tp and indoor The temperature difference from the temperature Tr (unit: ° C., hereinafter referred to as temperature difference ΔT), the air conditioning capacity required by the largest temperature difference ΔT among the indoor units 5-1 to 5-10 (here, heating capacity ) is the indoor unit that requests the maximum (hereinafter sometimes referred to as the maximum required capacity), indicating whether it is "applicable" / "not applicable", and the request described later Stores six items of capacity ignoring application indicating whether or not to ignore the maximum required capacity requested by the indoor unit having the largest temperature difference ΔT when the capacity ignoring condition is established, with "apply"/"not apply". It is

Every time the CPU 210 of the outdoor unit control means 200 acquires a signal including that the set temperature Tp has been changed in each of the indoor units 5-1 to 5-10 via the communication unit 230, the CPU 210 of the indoor unit 5-1 Each time the indoor temperature Tr detected by the indoor temperature sensor 63 is taken in periodically (for example, every 3 minutes) in each of 5-10, the items of the set temperature Tp and the indoor temperature Tr in the indoor unit operation state table 300 are updated. do. Further, the CPU 210 calculates the temperature difference ΔT and updates the item of the temperature difference ΔT in the indoor unit operating state table 300 every time the set temperature Tp and the indoor temperature Tr are taken. Note that the temperature difference ΔT is obtained by subtracting the room temperature Tr from the set temperature Tp during the heating operation, and by subtracting the set temperature Tp from the room temperature Tr during the cooling operation.

By the way, in the indoor unit operating state table 300 during heating operation shown in FIG. At −6, the temperature difference ΔT is 4.0° C. because the indoor temperature Tr is lower than the indoor temperature Tr of the other indoor units, which is the highest among the temperature differences ΔT of the other indoor units. This results in a large temperature difference ΔT (hereinafter referred to as maximum temperature difference ΔTm). As a situation in which such a situation occurs, there is a possibility that the air conditioning load of the indoor unit 5-6 becomes temporarily larger than that of the other indoor units, such as a place near a window or a doorway of a room. It is possible that it is installed.

Specifically, when the indoor unit 5-6 is installed near the window, the indoor temperature Tr detected by the indoor unit 5-6 becomes higher than the indoor temperature Tr detected by the other indoor units due to sunlight in summer. There is The influence of this solar radiation on the indoor temperature Tr changes depending on the length of time during which the sunlight enters the room through the window and the position of the sun. Also, in winter, the indoor temperature Tr detected by the indoor unit 5-6 may become lower than the indoor temperature Tr detected by the other indoor units due to cold air from the windows. The effect of cold air from this window changes depending on the presence or absence of solar radiation and the wind speed outside.

Further, when the indoor unit 5-6 is installed near the doorway of the room, the room temperature Tr detected by the indoor unit 5-6 is changed by opening and closing the door of the doorway and the outside air flows into the room. The indoor temperature Tr detected by the indoor unit may be higher in summer and lower in winter. The influence of outside air inflow from the doorway on the room temperature Tr changes depending on the length of time the door is open and the outside air temperature.

As described above, the indoor temperature Tr detected by the indoor unit 5-6 near the window or in the vicinity of the doorway is affected by solar radiation, door opening/closing time, and the like. ΔTm is also often temporary. Therefore, in many cases, the air conditioning capacity required by the indoor unit 5-6 becomes the maximum required capacity only temporarily. In this way, when the air conditioning capacity required by the indoor unit 5-6 becomes the maximum required capacity due to the temporary change in the room temperature Tr, there is no need to respond to this. Each time the air conditioning capacity required by the indoor unit 5-6 reaches the maximum required capacity, a target evaporating temperature or a target condensing temperature is set according to this maximum required capacity, and compression is performed so as to achieve these target evaporating temperatures or target condensing temperatures. If the rotation speed of the air conditioner 21 is increased, there is a possibility that the energy saving performance of the air conditioner 1 is lowered.

Therefore, in the air conditioner 1 of the present embodiment, if the required capacity ignoring condition described below is satisfied during the air conditioning operation, the maximum required capacity requested by the indoor unit with a large temperature difference ΔT is temporarily not adopted. Therefore, the rotational speed of the compressor 21 is not changed in order to maintain the air conditioning capacity currently exhibited. On the other hand, if the required capacity ignoring condition is not satisfied, the rotational speed of the compressor 21 is controlled so that the maximum required capacity required by the indoor unit with the largest temperature difference ΔT can be exhibited.

Here, the required capacity ignoring condition is determined in advance by conducting a test or the like, and the required capacity ignoring condition is established if all of the following three requirements are satisfied.

Requirement 1: The number of indoor units with the maximum temperature difference ΔTm is a predetermined number or less (for example, 1 unit)
Requirement 2: The temperature difference ΔT of each indoor unit other than the indoor unit having the maximum temperature difference ΔTm is within a predetermined range (for example,
within 1.5°C)
Requirement 3: The maximum temperature difference ΔTm is larger than the average temperature difference ΔT of each indoor unit (hereinafter referred to as the average temperature difference ΔTa) by a predetermined value (for example, 2°C higher)

In other words, the demanded capacity ignoring condition is used to determine whether or not one of the plurality of indoor units 5-1 to 5-10 requires significantly higher air conditioning capacity than the other indoor units. is the condition of

The above-mentioned three requirements of the required capacity ignoring condition will be described below. First, the first requirement (requirement 1) that "the number of indoor units having the maximum temperature difference ΔTm is equal to or less than a predetermined number" will be described. If Requirement 1 is satisfied, it indicates that there is a high possibility that the air conditioning load of the indoor unit requesting high air conditioning capacity is large. On the other hand, when Requirement 1 is not satisfied, that is, when there are more than a predetermined number of indoor units with the maximum temperature difference ΔTm, it indicates that a large number of indoor units require high air conditioning capacity. In this case, it is considered that the air conditioning load of the entire room in which the indoor units 5-1 to 5-10 are installed is large. In other words, by determining whether or not Requirement 1 is satisfied, it is possible to determine whether the maximum temperature difference ΔTm is due to the large air conditioning load of the entire room, or only the air conditioning load of a specific indoor unit. It is possible to determine whether is increasing. The specific numerical value of the predetermined number may be the number of indoor units installed near the window or near the doorway among the plurality of indoor units. Only one indoor unit 5-6 is installed near the window or doorway.

Next, the second requirement (requirement 2) that "the temperature difference ΔT of each indoor unit other than the indoor unit having the maximum temperature difference ΔTm is within a predetermined range" will be described. If Requirement 2 is satisfied, it indicates that the indoor temperature Tr of the indoor units other than the indoor unit having the maximum temperature difference ΔTm is close to the set temperature Tp. It is considered that the temperature of the room in which the indoor units 5-1 to 5-10 are installed is generally around the set temperature Tp. On the other hand, if the requirement 2 is not satisfied, the temperature difference ΔT of the indoor units other than the indoor unit having the maximum temperature difference ΔTm is also large (although not as large as the maximum temperature difference ΔTm). It is considered that there are a plurality of places where the temperature does not reach the vicinity of the set temperature Tp in the room where the indoor units 5-1 to 5-10 are installed. In other words, by determining whether or not Requirement 2 is satisfied, it is possible to determine whether or not the temperature difference ΔT of the indoor unit having the maximum temperature difference ΔTm is significantly larger than the temperature differences ΔT of the other indoor units. can be judged. A specific numerical value within the predetermined range may be appropriately determined for each air conditioner according to the number of indoor units, the size of the room in which it is installed, the air conditioning load of the room, and the like. In the harmony device 1, the temperature is within 1.5° C. as described above.

Finally, regarding the third requirement (requirement 3), "the maximum temperature difference ΔTm is larger than the average temperature difference ΔTa of the temperature differences ΔT of the indoor units other than the indoor units having the maximum temperature difference ΔTm by a predetermined value." explain. When the requirement 3 is satisfied, the difference between the maximum temperature difference ΔTm and the temperature difference ΔT of each indoor unit other than the indoor unit having the maximum temperature difference ΔTm is large, and the maximum temperature difference ΔTm is established. This means that the air conditioning capacity required by the indoor unit is significantly larger than the air conditioning capacity required by the other indoor units. On the other hand, when the requirement 3 is not satisfied, the difference between the maximum temperature difference ΔTm and the temperature difference ΔT of each indoor unit other than the indoor unit having the maximum temperature difference ΔTm is small, and the maximum temperature difference ΔTm is reached. In other words, the air conditioning capacity required by the indoor units that are currently in use does not differ much from the air conditioning capacity required by other indoor units. In other words, by determining whether or not Requirement 3 is satisfied, the air conditioning capacity required by the indoor unit with the maximum temperature difference ΔTm is a significantly larger value than the air conditioning capacity required by the other indoor units. It is possible to judge whether or not Note that the specific numerical value of the predetermined value may be appropriately determined for each air conditioner according to the number of indoor units and the total value of the air conditioning capacity. 2°C or higher.

Looking at whether or not the three requirements of the required capacity ignoring condition described above apply to the operating states of the air conditioner 1 listed in the indoor unit operating state table 300 of FIG. 5-10, the maximum value of the temperature difference ΔT is the temperature difference ΔT of the indoor unit 5-6: 4.0°C, and the maximum temperature difference ΔTm is the indoor unit 5-6 Therefore, it satisfies Requirement 1 of the condition for ignoring the required capacity. In addition, since the temperature differences ΔT of the indoor units other than the indoor units 5-6, which have the maximum temperature difference ΔTm, are all within 1.5° C., the requirement 2 of the required capacity ignoring condition is satisfied. The average temperature difference ΔTa of the temperature differences ΔT of the indoor units other than the indoor units 5-6 is (1.50+1.00+0+1.00+1.00+0.50+0+1.00+0.50)/9≈0.72°C. , the maximum temperature difference ΔTm: 4.0° C. is higher than the average temperature difference ΔTa: 0.72° C. by 2° C. or more. Therefore, if the states of the indoor units 5-1 to 5-10 are the states shown in the indoor unit operation state table 300 in FIG. Since it is satisfied, the condition for ignoring the requested capacity is satisfied.

Based on the above content, in the indoor unit operating state table 300, the item for ignoring the capacity of only the indoor units 5-6 is "applied" (all other indoor units are "non-applied"). In the outdoor unit 2, when the condition for ignoring the required capacity is satisfied, even if the temperature difference ΔT in the indoor units 5-6 is the maximum temperature difference ΔTm, the maximum required capacity determined based on the maximum temperature difference ΔTm is not used as the system required capacity, and the rotational speed of the compressor 21 is not changed. On the other hand, when the required capacity ignoring condition is not established, the maximum required capacity determined based on the maximum temperature difference ΔTm is set as the system required capacity, and the rotational speed of the compressor 21 is controlled to exhibit the system required capacity. In addition, when the required capacity ignoring condition is not satisfied, all the items of capacity ignoring application in the indoor unit operating state table 300 are set to "not applied".

Then, after a predetermined period of time (hereinafter referred to as a predetermined period of time t) has elapsed since the condition for ignoring the required capacity is established, the set temperature Tp and the indoor temperature Tr are taken in from the indoor unit 5-6, and the current temperature difference ΔT is calculated. (hereinafter referred to as current temperature difference ΔTn) is calculated. If the calculated current temperature difference ΔTn is equal to or greater than the predetermined threshold temperature difference ΔTt, the air conditioning capacity required by the indoor unit 5-6 has not decreased during the predetermined time t. Considering that a large air conditioning capacity is required rather than a target, the maximum required capacity based on the previously obtained maximum temperature difference ΔTm is set as the system required capacity, and the rotation of the compressor 21 is adjusted so that this system required capacity can be exhibited. control the numbers. On the other hand, if the current temperature difference ΔTn calculated after the lapse of the predetermined time is less than the threshold temperature difference ΔTt, it is assumed that the temperature difference ΔT in the indoor unit 5-6 has reached the maximum temperature difference ΔTm, which is temporary. The rotation of the compressor 21 is such that the air conditioning capacity determined based on the maximum value of the temperature differences ΔT of all the indoor units 5-1 to 5-10 including the indoor unit 5-6 can be exhibited. control the numbers.

Here, at the predetermined time t, the indoor temperature Tr rises again due to the fact that the cause of the temporary increase in the temperature difference ΔT in the indoor unit 5-6 has disappeared, for example, the opened door has been closed. (during heating operation) or falling (during cooling operation). minutes). Further, the threshold temperature difference ΔTt is a value that is obtained in advance by performing a test or the like and stored in the storage unit 220. After the predetermined time t has passed, the indoor temperature Tr detected by the indoor unit 5-6 rises. If the temperature difference ΔT is equal to or greater than the threshold temperature difference ΔTt without decreasing (during heating operation) or decreasing (during cooling operation), the air conditioning load in the indoor unit 5-6 is large and it is necessary to increase the air conditioning capacity. This value indicates that

<Flow of processing related to compressor control>
Next, using the flowchart of FIG. 3, when the air conditioner 1 in the present embodiment performs the air conditioning operation, the CPU 210 of the outdoor unit control means 200 is requested by each of the indoor units 5-1 to 5-10. The flow of processing when controlling the rotation speed of the compressor 21 in order to realize the air conditioning capacity that is required will be described. In FIG. 3, ST represents a processing step, and the number following ST represents the step number. Note that FIG. 3 only refers to the processing related to the present invention, and the description and explanation of other general controls related to the air conditioner 1 are omitted. Further, in FIG. 3, in addition to the set temperature Tp, the room temperature Tr, the temperature difference ΔT, the maximum temperature difference ΔTm, the current temperature difference ΔTn, and the predetermined time t, Ar is the required system capacity, and Ar is the maximum required capacity. Arm and ability subtraction value are Arp.

First, the CPU 210 takes in the set temperature Tp and the room temperature Tr from each of the indoor units 5-1 to 5-10 (ST1). Specifically, the CPU 210 transmits the temperature setting Tp transmitted from each of the indoor units 5-1 to 5-10 when the air conditioning operation is started or when the temperature setting Tp is changed by the user. capture through. Further, the CPU 210 periodically (every three minutes) acquires the indoor temperature Tr detected by the indoor temperature sensor 63 of each of the indoor units 5-1 to 5-10 via the communication unit 230. FIG. As described above, the CPU 210 updates the items of the set temperature Tp and the room temperature Tr in the indoor unit operating state table 300 stored in the storage unit 220 each time the set temperature Tp and the room temperature Tr are taken in. do.

Next, the CPU 210 subtracts the indoor temperature Tr from the set temperature Tp of each of the indoor units 5-1 to 5-10, and calculates the temperature difference ΔT for each of the indoor units 5-1 to 5-10 (ST2 ). The CPU 210 updates the item of the temperature difference ΔT in the indoor unit operating state table 300 stored in the storage unit 220 each time the temperature difference ΔT of each of the indoor units 5-1 to 5-10 is calculated.

Next, CPU 210 extracts maximum temperature difference ΔTm from among temperature differences ΔT calculated in ST2, and determines maximum required capacity Arm based on this maximum temperature difference ΔTm (ST3).

Next, the CPU 210 determines whether or not the required capacity ignoring condition is satisfied (ST4). As described above, the condition for ignoring the required capacity is that the number of indoor units with the maximum temperature difference ΔTm is equal to or less than a predetermined number (one unit in this embodiment), and the number of indoor units other than the indoor units with the maximum temperature difference ΔTm is The temperature difference ΔT of each indoor unit is within a predetermined range (within 1.5 ° C in this embodiment), and the average temperature difference ΔT of each indoor unit other than the indoor unit having the maximum temperature difference ΔTm This is when the maximum temperature difference ΔTm is larger than the temperature difference ΔTa by a predetermined value (in this embodiment, when it is 2° C. or higher).

If the required capacity ignoring condition is not satisfied (ST4-No), the CPU 210 sets the maximum required capacity Arm determined in ST3 to the system required capacity Ar, and sets the rotation speed of the compressor 21 to the rotation speed at which this system required capacity Ar can be exhibited. (ST11), and the process returns to ST1.

If the required capacity ignoring condition is satisfied (ST4-Yes), the CPU 210 determines the maximum required capacity Arm determined in ST3, that is, the indoor unit (in this embodiment, the indoor unit 5-6) that satisfies the required capacity ignoring condition. The air-conditioning capacity based on the temperature difference ΔT is not adopted, and the current system required capacity Ar and the current rotation speed of the compressor 21 are maintained (ST5), and the timer starts counting (ST6). In addition, CPU210 has a time-measurement function.

Next, the CPU 210 determines whether or not a predetermined time t has elapsed since the time measurement was started in ST6 (ST7). If the predetermined time t has not passed (ST7-No), the CPU 210 returns the process to ST7 and waits for the predetermined time t to pass.

If the predetermined time t has passed (ST7-Yes), the CPU 210 resets the timer (ST8), and the indoor unit that has the maximum temperature difference ΔTm in ST3, that is, the indoor unit that satisfies the required capacity ignoring condition (this In the embodiment, the latest set temperature Tp of the indoor unit 5-6) and the indoor temperature Tr are taken in to calculate the current temperature difference ΔTn (ST9).

Next, the CPU 210 determines whether or not the current temperature difference ΔTn calculated in ST9 is greater than or equal to the threshold temperature difference ΔTt (ST10). Note that the CPU 210 compares the absolute value of the current temperature difference ΔTn with the threshold temperature difference ΔTt.

If the current temperature difference ΔTn is not equal to or greater than the threshold temperature difference ΔTt (ST10-No), the CPU 210 returns the process to ST1. If the current temperature difference ΔTn is greater than or equal to the threshold temperature difference ΔTt (ST10-Yes), the CPU 210 advances the process to ST11.

As described above, in the air conditioner 1 of the present embodiment, if the required capacity disregard condition is satisfied during air conditioning operation, the maximum required capacity based on the maximum temperature difference ΔTm is not set as the system required capacity. , the rotation speed of the compressor 21 is not changed. As a result, frequent repetition of thermo-off/thermo-on can be suppressed in the indoor units other than the indoor unit in which the temperature difference ΔT has temporarily increased.

Further, after a predetermined time t has passed since the condition for ignoring the required capacity is satisfied, the current temperature difference ΔTn of the indoor unit that satisfies the condition for ignoring the required capacity is calculated. The required capacity based on the maximum temperature difference ΔTm calculated before the predetermined time tp elapses is defined as the system required capacity, and the rotational speed of the compressor 21 at which the system required capacity can be exhibited. As a result, when a high air-conditioning capacity is really required due to a high air-conditioning load in an indoor unit that satisfies the condition of ignoring the required capacity, the air-conditioning capacity can be exhibited, so that the user's comfort is not impaired. .

1 air conditioner 2 outdoor unit 5-1 to 5-10 indoor unit 21 compressor 51 indoor heat exchanger 63 indoor temperature sensor 200 outdoor unit control means 210 CPU
220 storage unit 230 communication unit 240 sensor input unit Ar required capacity Arm maximum required capacity Arp capacity subtraction value Tp set temperature Tr room temperature ΔT temperature difference ΔTa average temperature difference ΔTm maximum temperature difference ΔTn current temperature difference t predetermined time

Claims (2)

an outdoor unit having a compressor;
a plurality of indoor units having indoor temperature detection means for detecting indoor temperature;
a control means for controlling the driving of the compressor;
has
The control means is
From each of the indoor units, the indoor temperature detected by the indoor temperature detection means and the set temperature that is the target temperature for air conditioning operation set in each of the indoor units are taken in, and the indoor A temperature difference is obtained by reducing the temperature, a maximum required capacity is obtained based on the largest temperature difference among the temperature differences, and the compressor is controlled at a rotational speed at which the maximum required capacity can be exhibited,
If the required capacity ignoring condition is satisfied during air conditioning operation, the rotation speed of the compressor is not changed for a predetermined time after the required capacity ignoring condition is satisfied ,
The condition for ignoring the required capacity is that the number of indoor units having the maximum temperature difference is one, and the average value of the temperature differences of all the indoor units other than the indoor units having the same maximum temperature difference is Assume that the maximum temperature difference is greater than a predetermined value,
An air conditioner characterized by: The control means is
After the predetermined time has elapsed, calculating a current temperature difference by subtracting the indoor temperature from the set temperature of the indoor unit subject to the required capacity ignoring condition,
When the absolute value of the current temperature difference is greater than a predetermined threshold temperature difference, controlling the compressor at a rotational speed at which the maximum required capacity can be achieved.
The air conditioner according to claim 1, characterized by:

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