JP5954995B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner having a plurality of indoor units connected in parallel to a single outdoor unit to form a parallel refrigerant circuit and having an automatic return function after a power failure. .

  2. Description of the Related Art Conventionally, a general air conditioner is known that has a function of performing cooling of a room in which an indoor unit is arranged and automatically restarting operation when resuming power supply after a power failure. For example, there is an air conditioner described in Patent Document 1 that automatically restores all indoor units connected in parallel to outdoor units all at once when power is resumed after a power failure. In the case of this air conditioner, the operation control after the automatic return is performed in the same way as during normal startup.

JP 2009-41830 A

The above-described conventional general air conditioner performs normal operation even when power supply is resumed after a power failure, and automatically restores all indoor units uniformly, so that the refrigeration cycle operation of the refrigerant circuit reaches a steady state. Thus, it takes a considerable amount of time to exhibit 100% cooling capacity.
On the other hand, servers installed in the room where each indoor unit is placed are heating elements that generate heat from the heat sink, but these heating elements are uninterruptible power supplies even when a power failure occurs. It is often operated so that operation does not stop using power failure countermeasure devices such as the above. In addition, even when switching to private power generation without using a power failure countermeasure device, power supply on the side of the heat generation load (a heating element held by a server or the like) is often prioritized over the air conditioning device. That is, it is operated so that power supply to the air conditioner is started after power supply on the heat generating load side is completed.
Therefore, when the power supply of the air conditioner restarts after the state where only the air conditioner stops and the heat generating load is in operation at the time of a power failure, the heat generated from the heat generating load is retained. Therefore, there is a problem that cooling by the air conditioner cannot catch up, the air temperature around the heat generating load rises, and the reliability of continuation of operation on the heat generating load side is reduced.

  The present invention has been made to solve the above-described problems. The object of the present invention is to quickly reduce the air temperature around the heat generation load to the temperature during normal operation when power supply is resumed after a power failure. An air conditioner that can be obtained is obtained.

An air conditioner according to the present invention includes an outdoor unit comprising a compressor having a variable refrigerant discharge capacity and a heat source side heat exchanger, an expansion valve having a variable valve opening, an indoor side heat exchanger, a blower, and a temperature sensor. Are connected in parallel via a liquid refrigerant pipe connected to the outlet side of the heat source side heat exchanger and a gas refrigerant pipe connected to the suction side of the compressor, and the indoor unit is arranged. In an air conditioner that automatically cools the room and restarts the power supply after a power failure, when the cooling operation is resumed, the fans of the indoor unit are started to operate. determining a heating load from the difference between the detected temperature detected by the set temperature and the temperature sensor are, the valve opening of the expansion valve to operate in accordance with respective heat generation load, the indoor unit And it is characterized in that it comprises a resuming operation control means that control the flow rate of the refrigerant flowing inside the heat exchanger.

  The air conditioner of the present invention is configured to control the flow rate of the refrigerant flowing to each indoor unit by the expansion valve of the indoor unit according to the heat generation load detected by the heat generation load detection means when restarting operation after a power failure. Therefore, by supplying a part of the refrigerant that flows to the indoor unit with a small heat generation load detected by the heat generation load amount detection means to the indoor unit with a large heat generation load, the cooling capacity according to the heat generation load is obtained. This can provide an effect of efficiently reducing the ambient temperature of the heat generating load.

It is a schematic block diagram of the air conditioning apparatus in Embodiment 1 of this invention. It is a block block diagram which shows the control system of the said air conditioning apparatus. It is a block block diagram which shows the outdoor control part of the said control system. It is a schematic diagram which shows the installation environment example of the indoor unit of the said air conditioning apparatus. It is a figure of the flowchart which shows the process sequence of control of the said air conditioning apparatus. It is a figure of the flowchart which shows the process sequence of control of the air conditioning apparatus in Embodiment 2 of this invention.

Embodiment 1 FIG.
1 is a schematic configuration diagram of an air-conditioning apparatus according to Embodiment 1 of the present invention.
In FIG. 1, an air conditioner according to Embodiment 1 includes an outdoor unit 1 including a refrigerant discharge capacity variable compressor 2 and a heat source side heat exchanger 3 serving as a condenser, and a valve opening variable type. Two or more indoor units 6, 6, 6, comprising an electronic expansion valve 7, an indoor heat exchanger 8 serving as an evaporator, a blower 9, and a heat generation load amount detecting means 10 represented by, for example, a temperature sensor. Have a refrigerant circuit connected in parallel through a liquid refrigerant pipe 4 connected to the refrigerant outlet side of the heat source side heat exchanger 3 and a gas refrigerant pipe 5 connected to the refrigerant suction side of the compressor 2. doing. The air conditioner cools the room where the indoor unit 6 is placed, detects a power failure, and automatically resumes operation after resuming power supply. In this example, the heat generation load amount detection means 10 is incorporated in the indoor unit 6, but the heat generation load amount detection means 10 may be installed at an arbitrary position away from the indoor unit 6. .

FIG. 2 is a block diagram showing the control system of the air conditioner.
In FIG. 2, the outdoor unit 1 includes an outdoor control unit 11 that controls the operation of the outdoor unit 1 and a memory M represented by an EEPROM that stores program data and operation history data for operating the outdoor unit. . Each indoor unit 6 includes an indoor control unit 14 that controls the operation of the indoor unit 6, and an EEPROM that stores program data and operation history data for operating the indoor unit. The outdoor control unit 11 of the outdoor unit 1 and the indoor control unit 14 of each indoor unit 6 and between the indoor control units 14 are connected via a communication line so that data communication is possible.

  As shown in FIG. 3, the outdoor control unit 11 of the outdoor unit 1 is configured around an arithmetic processing unit CPU, and includes a timer T that counts processing time and the like. The arithmetic processing unit CPU, the timer T, the memory M, and the like are connected via a data bus DB so that data communication is possible. On the data input side of the data bus DB, the external input device 15 such as a keyboard and a mouse used for inputting data from the outside by hand or the like, and a plurality of heating load detection means 10, 10, 10 provided for each indoor unit 6. ,... Are connected to each other via each indoor control unit 14. Further, a plurality of electronic expansion valves 7, 7, 7,... Arranged for each indoor unit 6 are connected to the data input side of the data bus DB. In the arithmetic processing unit CPU, the function of the restart operation control means 20, which will be described in detail later, is set as program data. Further, the function of the restart operation control means 20 is described in detail later, the restart operation condition setting means 21, the priority order assigning means 22, the first selection unit operation means 23, the priority order update means 24, and the second selection unit operation. Each function of the means 25 is provided. In the memory M, a storage area for realizing the function of the related data storage means 26, which will be described in detail later, is secured.

Here, the operation | movement at the time of normal driving | operation in the refrigerant circuit of the air conditioning apparatus which concerns on Embodiment 1 is demonstrated.
The high-pressure gas refrigerant discharged from the variable capacity compressor 2 is condensed in the heat source side heat exchanger 3 to become a high-pressure liquid refrigerant, and a plurality of indoor units 6, 6, 6,.・ Supplied to Since the electronic expansion valve 7 of each indoor unit 6 is started to operate at the same initial valve opening degree for all the indoor units 6, an equal amount of refrigerant is distributed to each indoor unit 6. The refrigerant is depressurized by the electronic expansion valve 7 to become a low-pressure gas-liquid two-phase refrigerant and flows into the indoor heat exchanger 8. The indoor heat exchanger 8 exchanges heat with the indoor air to reduce the pressure. It becomes a gas refrigerant. The low-pressure gas refrigerant returns to the outdoor unit 1 through the gas refrigerant pipe 5 and performs a refrigeration cycle operation that returns to the suction side of the compressor 2.

Next, an environment in which the air conditioner according to Embodiment 1 is installed will be described. FIG. 4 is a schematic diagram of an installation environment example of the indoor unit of the air conditioner.
The heat generating load 12 to be cooled by the air conditioner is not stopped, and can be operated using a power failure countermeasure device such as an uninterruptible power supply even during a power failure. This is a heating element that generates heat. Further, for example, in the case of a server, the heat generation 13 from the heat generation load 12 varies depending on the number of servers stored in the server rack and the server operation rate, and is often not uniform in all locations. In many places, heat pools called hot spots are likely to occur. In FIG. 4, the size of the white arrow of the heat generation 13 indicates the amount of heat generation. In addition, devices such as servers have a temperature range suitable for operation. If the ambient temperature rises out of the temperature range, the reliability of operation is significantly reduced. In FIG. 4, the indoor unit 6 is shown as a ceiling-mounted type, but of course, the same applies to any installation type such as a floor-mounted type.

Next, an operation after power supply restarts from a power failure by the air conditioner of Embodiment 1 will be described. FIG. 5 shows a processing procedure after power supply restarts after a power failure.
First, the relationship data storage means 26 of the memory M represents a relationship between a plurality of ranks divided with respect to the magnitude of the heat generation load amount and a restart operation condition for reducing the heat generation load amount corresponding to each rank. Related data is stored in advance. Regarding the rank of the heat generation load described above, the first rank is a classification where the heat generation load is greater than or equal to the A value, the second rank is a classification where the heat generation load is less than the A value and the B value or more, and the third rank is the heat generation load amount. The classification that is less than the B value and greater than or equal to the C value and the fourth rank are defined as the classification that the heating load is less than the C value.

Therefore, after the power supply is resumed, first, in order to correctly detect the distribution of the heat generation load amount in the room, the arithmetic processing unit CPU starts the air blowing operation of all the indoor units 6, 6, 6,. Step S1) as a pre-operation function of the CPU. Such a blowing operation is a so-called thermo-off operation in which the compressor 2 is stopped or reduced in capacity when the room temperature detected by the temperature sensor reaches a set temperature, and the ventilation is mainly performed. If such an operation is started at the time of starting up the system, for example, it is possible to quickly proceed to the next control step without causing time loss.

Next, the heat generation load amount detecting means 10 detects the heat generation load amount in the vicinity of each indoor unit 6 and outputs it to the arithmetic processing unit CPU (step S2). Next, the arithmetic processing unit CPU refers to the relational data from the relational data storage means 26 of the memory M and determines the valve opening degree of the electronic expansion valve 7 at the start of operation according to the detected heat load. For example, if the heat generation load amount ≧ A (first rank), the electronic expansion valve 7 is set to the valve opening degree D. If B ≦ heat generation load amount <A (second rank), the electronic expansion valve 7 is set to the valve opening degree E. If C ≦ heat generation load amount <B (third rank), the electronic expansion valve 7 is set to the valve opening F, and if heat generation load amount <C (fourth rank), the cooling operation is performed instead of the cooling operation. (Step S3). Here, as a criterion for determining the magnitude of the heat generation load amount, for example, a temperature sensor is used as the heat generation load amount detection means 10, and the set temperature set for each indoor unit 6 and the detected temperature detected by the temperature sensor are For example, the A value is set to 3 ° C., the B value is set to 1 ° C., and the C value is set to about −1 ° C. Further, the valve opening degree D of the electronic expansion valve 7 is an opening degree at which the cooling capacity is 100%, the valve opening degree E is an opening degree at which the cooling capacity is about 70%, and the valve opening degree F is about 30%. It is good to set to each opening. In all the indoor units 6, when the heat generation load amount ≧ A, the maximum value of the inverter frequency for driving and controlling the compressor 2 is temporarily changed to the K value, so that it is higher than that during normal operation. A large amount of refrigerant can be supplied to the indoor unit 6. For example, the K value may be about 1.2 times the maximum value during normal operation.

That is, the processing in step S3 by the arithmetic processing unit CPU is performed by referring to the heat generation load amount detected by each heat generation load amount detection means 10 and the relation data stored in the relation data storage means 26 of the memory M. The indoor side heat exchanger of the indoor unit 6 according to the function of the restart operation condition setting means 21 for setting the restart operation condition of the indoor unit 6 and the heat generation load amount detected by the heat generation load amount detection means 10 when the operation is restarted. And the function of the resumption operation control means 20 for controlling the flow rate of the refrigerant flowing through 8 by operating the valve opening degree of the electronic expansion valve 7.

  Subsequently, the arithmetic processing unit CPU determines the valve opening degree of the electronic expansion valve 7 of each indoor unit 6 and starts a cooling operation. The nearby heat load is detected again (step S4). Here, the predetermined time G may be about 1 minute, for example. Next, the arithmetic processing unit CPU determines and sets a change value of the valve opening degree of the electronic expansion valve 7 in accordance with the heat load amount newly detected. That is, if the heat generation load amount ≧ A, the valve opening + H pulse (the pulse corresponds to the valve opening) is set, and if B ≦ heat generation load <A, the valve opening + I pulse is set, and C ≦ heat generation If the load amount <B, the valve opening is not changed, and if the heat generation load <C, the valve opening-J pulse is set (step S5). For example, the H value is set to 30 pulses, the I value is set to 10 pulses, and the J value is set to 20 pulses. And the process of step S4 and step S5 is repeatedly performed for every predetermined time G. FIG. In step S4, when the heat generation load amount <B is detected in all the indoor units 6, 6, 6,..., Or when a predetermined time L has elapsed, the control operation is terminated and the normal operation operation is started. And migrate. Here, the predetermined time L may be set to about 20 minutes, for example.

  As described above, according to the air conditioning apparatus of the first embodiment, by controlling the valve opening degree of the electronic expansion valve 7 in accordance with the heat generation load amount, the refrigerant of the indoor unit 6 that does not require much cooling capacity is used. The unit is installed in a hot spot, must exhibit 100% cooling capacity, and can be supplied toward the indoor unit 6 where it is necessary to quickly cool the object to be cooled. As a result, it is possible to prevent an exothermic load such as a server from excessively rising in temperature.

Embodiment 2. FIG.
Next, an air conditioning apparatus according to Embodiment 2 of the present invention will be described. The air conditioning apparatus of the second embodiment has the same configuration as the apparatus shown in FIGS. 1 to 4, but the arithmetic processing unit CPU is configured to operate the priority order assigning unit 22 and the first selection unit, which will be described later. Each function of means 23, priority order update means 24, and second selection unit operation means 25 is provided. Then, the operation | movement after the electric power supply restarts from the power failure by the air conditioning apparatus of Embodiment 2 is demonstrated. FIG. 6 shows a processing procedure of control after power supply is resumed from a power failure by the air conditioner according to the second embodiment.

After the power supply is resumed, first, in order to correctly detect the distribution of the heat generation load amount in the room, the arithmetic processing unit CPU starts the air blowing operation of all the indoor units 6 for a while (step S1: pre-operation function). Next, the heat generation load amount detecting means 10 detects the heat generation load amount in the vicinity of each indoor unit 6 and outputs it to the arithmetic processing unit CPU (step S2). Thereafter, the arithmetic processing unit CPU determines the priority order of the indoor units 6 for starting the cooling operation based on the detected heat load. At this time, the arithmetic processing unit CPU assigns priorities such as first and second from the indoor unit 6 having a large heat generation load. However, all the indoor units 6 with the heat generation load amount ≧ A are ranked first (step S6). Here, as a criterion for determining the magnitude of the heat generation load amount, for example, a temperature sensor is used as the heat generation load amount detection means 10, and the set temperature set for each indoor unit 6 and the detected temperature detected by the temperature sensor are If the difference is used, the value A is preferably set to 3 ° C. In other words, the processing of step S6 by the arithmetic processing unit CPU is performed by the priority order assigning means 22 that assigns a higher priority order for starting operation in the order of the indoor units with the large heat generation load amounts detected by each heat generation load amount detection means 10. It becomes the embodiment of the function.

  Next, the arithmetic processing unit CPU starts operation according to the priority order determined in step S6. At this time, only the indoor unit 6 with the first priority is started, and the blower operation (thermo OFF operation) is continued with respect to the indoor units 6 with the second and lower ranks. Moreover, when the heat generation load amount ≧ A in all the indoor units 6, by temporarily changing the maximum value of the inverter frequency for driving and controlling the compressor 2 to a value K larger than that during normal operation, A larger amount of refrigerant than that during normal operation can be supplied to all the indoor units 6. For example, the maximum value K may be about 1.2 times that during normal operation (step S7). In other words, the processing of step S7 by the arithmetic processing unit CPU embodies the function of the first selection unit operating means 23 that selects and operates only the indoor unit 6 having the highest priority given by the priority assigning means 22. It is a thing. Then, after the operation is started, when the time counted by the timer T has passed the predetermined time G, the heat generation load amount in the vicinity of each indoor unit 6 detected by the heat generation load amount detection means 10 is again calculated. (Step S4). Here, the predetermined time G may be about 1 minute, for example.

Next, in step S8, the arithmetic processing unit CPU again determines the priority order based on the detected heat load, and updates the priority order (step S8). At this time, if the priority order is changed, the indoor unit 6 that has been newly raised to the first place is activated, and the indoor unit 6 that has been lowered from the first place to the second place or less is a so-called thermo-ON operation in which the compressor 2 is normally operated. While the operation is continued, the opening degree of the electronic expansion valve 7 is reduced to suppress the cooling capacity. For example, when the electronic expansion valve 7 is controlled based on the degree of superheat of the indoor heat exchanger 8, the cooling capacity can be increased by setting the superheat degree target value to be larger than the optimum value and increasing the superheat degree. Suppress. Further, if the priority order does not change, if the heating load <B is satisfied for the first indoor unit 6, the cooling capacity of the first indoor unit 6 is suppressed as in the case where the priority order is changed. At the same time, the second indoor unit 6 starts operating. If the first indoor unit 6 has a heat generation load amount ≧ B, the operation state is maintained as it is.

That is, the processing of step S8 by the arithmetic processing unit CPU is the heat generated by the heat generation load amount detecting means 10 newly detected when the indoor unit 6 selected by the first selection unit operating means 23 is operated for a predetermined time G. The function of the priority update means 24 for updating the priority order in the order of the indoor unit 6 with the largest load amount is embodied, and the indoor unit whose priority order updated by the priority order update means 24 is higher. 6 is realized by the function of the second selection unit operation means 25 for controlling the heat generation load amount to be reduced by operating 6.

Then, the arithmetic processing unit CPU repeats the processes of step S4 and step S8 every predetermined time G, and detects the heat generation load amount <B in all the indoor units 6, 6, 6,. At the time or when the predetermined time L has elapsed, the present control operation is terminated and the routine shifts to the normal operation. Here, the predetermined time L is set to about 20 minutes, for example. As described above, the functions of the priority order assigning means 22, the first selection unit operation means 23, the priority order update means 24, and the second selection unit operation means 25 are detected by the heat generation load amount detection means 10 when the operation is resumed. A part of the function of the restart operation control means 20 that controls the flow rate of the refrigerant flowing through the indoor heat exchanger 8 of the indoor unit 6 by operating the valve opening degree of the electronic expansion valve 7 according to the heat generation load amount. It is composed.

  As described above, according to the air conditioner of the second embodiment, by controlling the valve opening degree of the electronic expansion valve 7 in accordance with the heat generation load, a part of the refrigerant of the indoor unit 6 that does not require much cooling capacity. Can be supplied to the indoor unit 6 that must be installed at the hot spot and must exhibit 100% cooling capacity and needs to cool the object to be cooled quickly. As a result, it is possible to prevent an exothermic load such as a server from excessively rising in temperature.

  In the above embodiment, the outdoor control unit 11 of the outdoor unit 1 has the function of the control means according to the present invention, but the present invention is not limited thereto. Instead of the outdoor control unit 11, a separate and independent external control device can be provided with the function of the control means. Alternatively, any of the indoor control units 14 of the indoor units 6 may have the function.

  DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Compressor, 3 Heat source side heat exchanger, 4 Liquid refrigerant piping, 5 Gas refrigerant piping, 6 Indoor unit, 7 Electronic expansion valve, 8 Indoor heat exchanger, 9 Blower, 10 Exothermic load amount detection means 11 Outdoor control section, 12 Heat generation load, 13 Heat generation, 14 Indoor control section, 15 External input device, 20 Restart operation control means, 21 Restart operation condition setting means, 22 Priority assignment means, 23 First selection unit operation means, 24 priority update means, 25 second selection unit operation means, 26 relation data storage means, CPU arithmetic processing unit, M memory.

Claims (3)

An outdoor unit comprising a refrigerant discharge capacity variable compressor and a heat source side heat exchanger, and a plurality of indoor units comprising a valve opening variable type expansion valve, an indoor heat exchanger, a blower and a temperature sensor ; Are connected in parallel via a liquid refrigerant pipe connected to the outlet side of the heat source side heat exchanger and a gas refrigerant pipe connected to the suction side of the compressor, and the indoor unit in which the indoor unit is disposed is cooled. In an air conditioner that automatically resumes operation when power is supplied after a power failure,
When the cooling operation is resumed, the operation of each blower of the indoor unit is started, and the heating load amount is determined from the difference between the set temperature set in the indoor unit and the detected temperature detected by the temperature sensor. depending on the heating load by operating the valve opening degree of the expansion valve, characterized in that it comprises a resuming operation control means that control the flow rate of the refrigerant flowing in the indoor side heat exchanger of the indoor unit air Harmony device. The heating load of a plurality of ranks that are divided about the size, corresponding to the heat load relationship data representing the relationship between the resume operating conditions for reducing the can prestored relationship data stored in each rank Having means,
Resuming operation control means, with reference to the relationship data stored heating load that is determined to respectively in the relationship data storage means comprises a restart operation condition setting means for setting the restarting operation conditions of the indoor units respectively The air conditioner according to claim 1, wherein The resumption operation control means , a priority order giving means for giving a higher priority order to start operation in the order of the indoor units with the larger heat generation load amount,
First selected unit operating means for selecting and operating only the indoor unit having the highest priority given by the priority order giving means;
When the indoor unit selected by the first selecting unit operating means is operated a predetermined time, again the set temperature and the difference has been heat generation load is large indoor determined from said detected temperature by said resuming operation control means Priority update means for updating the priority in order of units;
Claims, characterized in that it comprises a second selecting unit operating means updated priority is controlled to reduce the heating load by operating the indoor unit was higher by the priority updating means Item 2. The air conditioner according to Item 1.

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