CN112449672A

CN112449672A - Air conditioner

Info

Publication number: CN112449672A
Application number: CN202080002278.6A
Authority: CN
Inventors: 牛山悟士; 法福守
Original assignee: Hitachi Johnson Controls Air Conditioning Inc
Current assignee: Hitachi Johnson Controls Air Conditioning Inc
Priority date: 2019-07-03
Filing date: 2020-04-17
Publication date: 2021-03-05
Also published as: TWI731707B; JP6704491B1; JP2021011953A; WO2021002087A1; TW202102801A

Abstract

The invention provides an air conditioner, which aims to prevent the degradation of air conditioning performance caused by the corrosion of an outdoor heat exchanger. An air conditioner having an outdoor unit and an indoor unit is provided with: an outdoor heat exchanger having fins; and a control unit that controls: and performing an operation of attaching frost or ice to the surface of the fin provided in the outdoor heat exchanger, and after the operation is started, performing a next operation of attaching frost or ice to the surface of the fin when a 1 st period, which is a period integrated according to the passage of time, has elapsed regardless of the presence or absence of an air conditioning operation.

Description

Air conditioner

Technical Field

The present invention relates to an air conditioner.

Background

In an air conditioner, as the usage time is longer, more dust adheres to a heat exchanger of an outdoor unit. On the other hand, patent document 1 discloses a technique of forming a hydrophilic coating film on the surface of a fin at a predetermined timing to maintain antifouling property and hydrophilicity for a long period of time.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-228221

Disclosure of Invention

Problems to be solved by the invention

However, in an area near the coast, corrosion caused by salt in seawater causes melting of fins of a heat exchanger, and there is a problem that the plate thickness of the fins is reduced or holes are formed. When such a phenomenon occurs, the heat exchange rate of the fins decreases, and the performance of the air conditioner decreases.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent deterioration of air conditioning performance due to corrosion of an outdoor heat exchanger.

Means for solving the problems

The invention is an air conditioner with outdoor unit and indoor unit, it has: an outdoor heat exchanger provided with fins; and a control unit that performs control in the following manner: and performing an operation of attaching frost or ice to the surface of the fin provided in the outdoor heat exchanger, and performing a next operation of attaching frost or ice to the surface of the fin when a 1 st period, which is a period integrated according to a lapse of time, has elapsed regardless of whether or not an air conditioning operation has been performed after the operation is started.

Effects of the invention

According to the present invention, it is possible to prevent the degradation of air conditioning performance caused by corrosion of the outdoor heat exchanger.

Drawings

Fig. 1 is a view showing an external appearance of an air conditioner.

Fig. 2 is a diagram showing a refrigerant circuit of an air conditioner.

Fig. 3A is a diagram of an outdoor heat exchanger.

Fig. 3B is a sectional view of the outdoor heat exchanger.

Fig. 4 is a flowchart showing the cleaning operation management process.

Fig. 5 is an explanatory diagram of the timing of the cleaning operation.

Detailed Description

Fig. 1 is a configuration diagram showing an external appearance of an air conditioner 1 according to an embodiment. The air conditioner 1 performs air conditioning by circulating a refrigerant in a refrigeration cycle (heat pump cycle). As shown in fig. 1, the air conditioner 1 includes: an indoor unit 10 installed indoors (air-conditioned space), an outdoor unit 20 installed outdoors (outdoors), and a remote controller 30 operated by a user.

The indoor unit 10 includes a remote control communication unit 11. The remote control communication unit 11 transmits and receives a predetermined signal to and from the remote controller 30 by infrared communication or the like. For example, the remote control communication unit 11 receives signals such as an operation/stop command, a change in set temperature, a change in operation mode, and a setting of time from the remote controller 30. The remote control communication unit 11 transmits a detected value of the indoor temperature and the like to the remote controller 30. Note that, although not shown in fig. 1, the indoor unit 10 and the outdoor unit 20 are connected to each other via a refrigerant pipe and are also connected to each other via a communication line.

Fig. 2 is a diagram showing a refrigerant circuit Q of the air conditioner 1 according to the embodiment. Note that solid arrows shown in fig. 2 indicate the flow of the refrigerant during the heating operation. In addition, the dashed arrows shown in fig. 2 indicate the flow of the refrigerant during the cooling operation.

The indoor unit 10 includes an indoor heat exchanger 12, an indoor fan 14, a temperature sensor 15, and an indoor control unit 16 in addition to the remote control communication unit 11. In the indoor heat exchanger 12, heat is exchanged between the refrigerant flowing along the heat transfer tubes (not shown) thereof and the indoor air sent from the indoor fan 14. The indoor heat exchanger 12 operates as a condenser or an evaporator by switching the four-way valve 25 described later. The indoor fan 14 is disposed in the vicinity of the indoor heat exchanger 12. The indoor fan 14 sends indoor air to the indoor heat exchanger 12 by driving of an indoor fan motor 14 a. The temperature sensor 15 measures the indoor temperature. The indoor control unit 16 is a control board including a CPU, a storage unit, and a communication unit. The indoor control unit 16 controls the entire indoor unit 10. The indoor control unit 16 further performs communication with an outdoor control unit 28 of the outdoor unit 20, which will be described later, to control the entire air conditioner 1 including the outdoor unit 20.

The outdoor unit 20 includes: a compressor 21; an outdoor heat exchanger 22; an outdoor fan 23; an outdoor expansion valve 24 (expansion valve); a four-way valve 25;

temperature sensors

26, 27; and an outdoor control unit 28. The compressor 21 is driven by a compressor motor 21a to compress a low-temperature low-pressure gas refrigerant and discharge the compressed gas refrigerant as a high-temperature high-pressure gas refrigerant. In the outdoor heat exchanger 22, heat is exchanged between the refrigerant flowing along the heat transfer tubes (not shown) and the outside air sent from the outdoor fan 23. The outdoor heat exchanger 22 operates as a condenser or an evaporator by switching the four-way valve 25.

As shown in fig. 1, the outdoor fan 23 is disposed in the vicinity of the outdoor heat exchanger 22. The outdoor fan 23 sends the outdoor air to the outdoor heat exchanger 22 by driving the outdoor fan motor 23 a. The outdoor expansion valve 24 has a function of reducing the pressure of the refrigerant condensed in the "condenser" (one of the outdoor heat exchanger 22 and the indoor heat exchanger 12). The refrigerant decompressed by the outdoor expansion valve 24 is guided to the "evaporator" (the other of the outdoor heat exchanger 22 and the indoor heat exchanger 12).

The four-way valve 25 is a valve for switching the flow path of the refrigerant according to the operation mode of the air conditioner 1. In the cooling operation, a refrigeration cycle is formed in which the refrigerant is circulated in the order of the compressor 21, the outdoor heat exchanger 22 (condenser), the outdoor expansion valve 24, and the indoor heat exchanger 12 (evaporator) as indicated by broken arrows by switching of the four-way valve 25. In the heating operation, a refrigeration cycle is formed in which the refrigerant is circulated in the order of the compressor 21, the indoor heat exchanger 12 (condenser), the outdoor expansion valve 24, and the outdoor heat exchanger 22 (evaporator) as indicated by solid arrows by switching the four-way valve 25. That is, in the refrigerant circuit Q in which the refrigerant circulates in the refrigeration cycle through the compressor 21, the "condenser", the outdoor expansion valve 24, and the "evaporator" in this order, one of the "condenser" and the "evaporator" is the outdoor heat exchanger 22, and the other is the indoor heat exchanger 12. The temperature sensor 26 measures the temperature of the outdoor heat exchanger 22. The temperature sensor 27 measures the outdoor temperature. The outdoor control unit 28 controls the entire outdoor unit 20.

Fig. 3A and 3B are views showing the outdoor heat exchanger 22. Fig. 3(a) is a schematic view of the outdoor heat exchanger 22. Fig. 3(B) is a sectional view of the outdoor heat exchanger 22. The outdoor heat exchanger 22 includes a tube 22a as a heat transfer tube through which the refrigerant flows, and a plurality of fins 22b connected to the periphery of the tube 22 a. As described above, dust adheres to the fins 22b when the air conditioner 1 is used. In addition, when the air conditioner 1 is installed near the coast, there is a problem that the fins 22b are melted due to corrosion caused by salt of seawater.

In contrast, the air conditioner 1 according to the present embodiment frosts the surface of the fins 22b, and melts the frost to wash away dust and salt adhering to the fins 22 b. Specifically, the indoor control unit 16 of the indoor unit 10 operates the outdoor heat exchanger 22 as an evaporator, and causes the outdoor heat exchanger 22 to freeze moisture in the air taken in by the outdoor unit 20. That is, the indoor control unit 16 attaches at least one of frost and ice to the surface of the fin 22 b. The indoor control unit 16 then dissolves the frost and ice. This allows the outdoor heat exchanger 22 to be cleaned of dust and salt. This series of operations is referred to as a cleaning operation of the outdoor heat exchanger 22. In the air conditioner 1 of the present embodiment, the cleaning operation is performed under the control of the indoor control unit 16.

Fig. 4 is a flowchart showing a cleaning operation management process performed by the indoor control unit 16 of the indoor unit 10. Fig. 5 is an explanatory diagram of the timing of the cleaning operation. The cleaning operation management process will be described with reference to fig. 5 as appropriate. The indoor control unit 16 periodically performs a cleaning operation. The cleaning operation management process controls the timing of execution of the cleaning operation. After the installation of the air conditioner 1 is completed, the indoor control unit 16 starts the cleaning operation in step S400 after a predetermined period of time has elapsed. Specifically, the indoor control unit 16 switches the four-way valve 25 in the direction indicated by the solid line in fig. 2, and operates the outdoor heat exchanger 22 as an evaporator, thereby freezing moisture in the air taken in by the outdoor unit 20 in the outdoor heat exchanger 22. The indoor control unit 16 adjusts the opening degree of the outdoor expansion valve 24 based on the outdoor temperature measured by the temperature sensor 27. Specifically, the indoor control unit 16 controls the opening degree of the outdoor expansion valve 24 to be smaller as the outdoor temperature becomes higher. This avoids the need for an excessively long time for the cleaning operation, and enables efficient cleaning operation.

When the cleaning operation is started in step S400, the indoor control unit 16 starts counting of the cleaning waiting time in step S401. Here, the washing waiting time is a value accumulated by the elapse of the passage time, and is counted regardless of the presence or absence of the air conditioning operation. The cleaning waiting period is a period from the timing of executing the cleaning operation to the execution of the next cleaning operation. The cleaning waiting period is a predetermined period. In the present embodiment, the cleaning waiting period is set to 2 months. As shown in fig. 5, the washing waiting period is counted from the start timing of the washing operation. In the present embodiment, the cleaning waiting period is set to 2 months, but the value of the cleaning waiting period is not limited to the embodiment.

Next, in step S402, the indoor control unit 16 determines whether or not an instruction to interrupt the cleaning operation is received, based on the user operation of the remote controller 30. When the indoor control unit 16 receives the interrupt instruction (yes at step S402), the process proceeds to step S403. If the indoor control unit 16 does not receive the interrupt instruction (no in step S402), the process proceeds to step S404. In step S403, the indoor control unit 16 interrupts the cleaning operation, and the process proceeds to step S405. In this way, since the interruption instruction is given priority even during the washing operation, the user can perform the air conditioning operation without waiting for the washing operation to be ended even during the washing operation.

In step S404, the indoor control unit 16 determines whether or not the cleaning operation is finished. After the cleaning operation is started, the indoor control unit 16 obtains the temperature measured by the temperature sensor 26 provided in the outdoor heat exchanger 22. Then, the indoor control unit 16 determines that the cleaning operation is ended when a predetermined time has elapsed in a state where the measured temperature is equal to or lower than a predetermined temperature threshold value. Here, the temperature threshold is set to a temperature below freezing point such as minus 5 ℃. The constant time is set to, for example, 5 minutes. The temperature threshold and the constant time are set in advance. Further, since the temperature of the outdoor heat exchanger 22 may not be reduced to the temperature threshold value or less depending on the environment, the indoor control unit 16 may end the cleaning after a predetermined time has elapsed from the start of the cleaning.

Next, in step S405, the indoor control unit 16 dries the outdoor heat exchanger 22. Specifically, the indoor control unit 16 drives the outdoor fan motor 23a for a predetermined time to rotate the outdoor fan 23. As another example, the indoor control unit 16 switches the four-way valve 25 in a direction indicated by a broken line in fig. 2, and can operate the outdoor heat exchanger 22 as a condenser to heat the outdoor heat exchanger 22. Thereby dissolving the frost. In another example, the indoor controller 16 may perform both heating and driving of the outdoor fan 23.

In the above, the cleaning operation is completed by the processing of step S400 to step S405. When the cleaning operation process is completed, the indoor control unit 16 waits until the timing for executing the next cleaning operation process. Specifically, in step S406, the indoor control unit 16 determines whether or not the cleanable timing has elapsed. Here, the cleanable timing is a timing before the end timing constant period of the cleaning waiting period (see fig. 5). In the present embodiment, the cleanable timing is 1 week before the end timing of the cleaning waiting period. However, the cleanable timing is not limited to 1 week as long as it is a timing before the processing wait timing is constant. The indoor control unit 16 waits until the cleanable timing elapses (no in step S406), and proceeds to step S407 when the cleanable timing elapses (yes in step S406).

In step S407, the indoor control unit 16 determines whether the air conditioning operation has ended. When the air conditioning operation is started and then ended, the indoor control unit 16 determines that the air conditioning operation has ended. When the air conditioning operation is finished (yes in step S407), the indoor control unit 16 advances the process to step S408. When the air conditioning operation is not completed, that is, when the air conditioning operation is not performed or during the air conditioning operation (no in step S407), the indoor control unit 16 advances the process to step S410.

In steps S408 and S409, the indoor control unit 16 determines whether or not the cleaning operation start condition is satisfied. That is, in step S408, the indoor control unit 16 obtains the outdoor temperature from the temperature sensor 27. Then, the indoor control unit 16 compares the outdoor temperature with the 1 st temperature threshold value. Here, the 1 st temperature threshold is set in advance. The 1 st temperature threshold is set to, for example, 32 ℃. When the outdoor temperature is lower than the 1 st temperature threshold (yes at step S408), the indoor control unit 16 advances the process to step S409. When the outdoor temperature is equal to or higher than the 1 st threshold (no in step S408), the indoor control unit 16 determines that the start condition is not satisfied, and advances the process to step S410.

In step S409, the indoor control unit 16 obtains the indoor temperature from the temperature sensor 15. Then, the indoor control unit 16 compares the indoor temperature with the 2 nd temperature threshold value. Here, the 2 nd temperature threshold is set in advance. The 2 nd temperature threshold is set to 32 ℃, for example. The 1 st temperature threshold and the 2 nd temperature threshold may be equal or different values.

When the indoor temperature is equal to or higher than the 2 nd threshold (no in step S409), the indoor control unit 16 determines that the start condition is not satisfied, and the process proceeds to step S410. When the indoor temperature is lower than the 2 nd threshold (yes in step S409), the indoor control unit 16 determines that the start condition is satisfied, and the process proceeds to step S400. That is, when the start condition is satisfied after the air conditioning operation is completed, the indoor control unit 16 starts the cleaning operation in step S400.

In step S410, the indoor control unit 16 determines whether or not the cleanable execution timing has elapsed. Here, the cleaning execution timing refers to a timing between the end timing of the cleaning waiting period and the cleanable timing. In the present embodiment, the cleaning execution timing is a timing 1 day before the end timing of the cleaning waiting period (see fig. 5). However, the cleaning execution timing is not limited to the embodiment as long as it is a timing between the end timing of the cleaning waiting period and the cleanable timing.

When the cleaning execution timing has elapsed (yes in step S410), the indoor control unit 16 advances the process to step S411. When the cleaning execution timing has not elapsed (no in step S410), the indoor control unit 16 advances the process to step S407. In this way, when the cleaning execution timing does not elapse, the processing of steps S407 to S409 is performed, and the air conditioner waits until the start condition is satisfied after the air conditioning operation. In step S411, the indoor control unit 16 determines whether or not the time at the time of the processing has elapsed a predetermined time at night. Here, the predetermined time at night is, for example, a time from 0 am to 3 pm, and is set in advance. For example, in the air conditioner 1, a time period from 0 am to 3 pm is set as a settable time period, and a user sets a desired time from the time period to set a predetermined time at night.

The indoor control unit 16 waits until the scheduled time at night (no in step S411), and when the scheduled time at night has elapsed (yes in step S411), the process proceeds to step S400. That is, after the cleaning execution timing has elapsed, the indoor control unit 16 executes the cleaning operation on the condition that the time at night has elapsed, regardless of whether or not the start condition is satisfied. In this way, when the timing of ending the cleaning waiting period approaches the timing of ending the cleaning waiting period in a state where the start condition is not satisfied, the cleaning operation is executed on the condition that the set time has elapsed, regardless of whether the start condition is satisfied or not.

As described above, the indoor control unit 16 can periodically perform the freezing process with reference to the cleaning waiting period. The cleaning of dust according to the use of the air conditioner 1 is performed effectively according to the use time of the air conditioner 1. However, in the coastal region, salt content accumulates with the passage of time from the time of installation of the air conditioner 1 regardless of the time of use. In contrast, in the air conditioner 1 of the present embodiment, since the indoor control unit 16 periodically performs the cleaning operation of the outdoor heat exchanger 22 regardless of the presence or absence of the air conditioning operation, salt can be removed before the corrosion of the fins 22b occurs. Thus, the degradation of the air conditioning performance due to the corrosion of the outdoor heat exchanger 22 can be prevented.

The indoor control unit 16 executes the cleaning operation during a time period from the cleanable timing cleaning execution timing, that is, after the air conditioning operation is ended and when the start condition is satisfied. Therefore, the condition that the user feels uncomfortable due to the fact that the sudden cleaning operation is started when the power supply of the air conditioner is not switched on can be avoided.

In addition, when the outdoor temperature is high, it is difficult to perform the cleaning operation efficiently. Therefore, the cleaning operation is not performed when the outdoor temperature is equal to or higher than the threshold value, but the outdoor temperature is lower than the 1 st temperature threshold value as a starting condition. Similarly, even when the indoor temperature is high, it is difficult to perform the cleaning operation efficiently, and therefore, the indoor temperature is lower than the 2 nd temperature threshold as the start condition. Thus, the cleaning operation can be performed at an appropriate timing with respect to efficiency.

Further, when the start condition is not satisfied and the cleaning execution timing has elapsed after the air conditioning operation is ended, the indoor control unit 16 executes the cleaning operation on the condition that the predetermined time at night has elapsed, regardless of whether the cleaning execution timing is after the air conditioning operation and regardless of whether the start condition is satisfied. This makes it possible to reliably start the cleaning operation before the end timing of the cleaning waiting period elapses.

A modification 1 of the embodiment will be described. In the present embodiment, the cleaning operation is executed after the end of the air-conditioning operation and when the start condition is satisfied during the time between the cleanable timing and the cleaning execution timing. However, these conditions are not essential, and for example, the indoor control unit 16 may execute the washing operation when the start condition is satisfied regardless of the timing at which the air conditioning operation is ended. In another example, the indoor control unit 16 starts the cleaning operation only after the air conditioning operation is finished, regardless of whether or not the start condition is satisfied.

As a modification 2, in the present embodiment, the cleaning operation management process is performed by the indoor control unit 16, but the main body of the cleaning operation management process is not limited to the indoor control unit 16. As another example, the outdoor control unit 28 of the outdoor unit 20 may execute the cleaning operation management process. The management processing can be realized by cooperation of the indoor control unit 16 and the outdoor control unit 28. In this way, the control unit corresponds to at least one of the indoor control unit 16 and the outdoor control unit 28. In addition, in the air conditioning system including the management device that manages 1 or more indoor units and 1 or more outdoor units, the management device may execute the cleaning operation management process for each of the outdoor units included in the air conditioning system.

In the case of the 3 rd modification, the washing waiting period may be different depending on the season. For example, when it is known that the degree of salt damage varies depending on the season, the indoor control unit 16 may set a time longer than the season having a small degree of salt damage as the cleaning waiting period in the season having a large degree of salt damage.

In the case of the 4 th modification, the cleaning waiting period may be set according to the set environment. For example, the outdoor unit 20 includes an anemometer, not shown, and the indoor control unit 16 can set a cleaning waiting period of an appropriate length in accordance with the air volume detected by the anemometer for a predetermined period of time, for example, 1 month. As another example, the indoor control unit 16 may measure the outdoor temperature, the outdoor humidity, and the like for a predetermined period, and set a cleaning waiting period of an appropriate length based on the measured outdoor temperature and outdoor humidity.

The indoor control unit 16 may obtain the position information from a portable device (not shown) such as a smartphone held by the user of the air conditioner 1. The indoor control unit 16 calculates the distance from the sea based on the position information and the map information stored in the indoor control unit 16, and sets a cleaning waiting period according to the distance from the sea. Further, as a simpler configuration, for the air conditioner 1 shipped to an area with a large salt damage, for example, the selection buttons of "approach the coast" and "a building with wind shielding from the coast" may be selected at the remote controller 30 at the time of installation. At this time, the indoor control unit 16 may set the cleaning waiting period based on the selected information.

Description of the symbols

1-air conditioner, 10-indoor unit, 16-indoor control unit, 20-outdoor unit, 22-outdoor heat exchanger, 22 b-fin, 23-outdoor fan, 28-outdoor control unit.

Claims

1. An air conditioner having an outdoor unit and an indoor unit, characterized in that,

comprising:

an outdoor heat exchanger having fins; and

a control unit which controls: and performing an operation of attaching frost or ice to the surface of the fin provided in the outdoor heat exchanger, and after the operation is started, performing a next operation of attaching frost or ice to the surface of the fin when a 1 st period, which is a period integrated according to the passage of time, has elapsed regardless of the presence or absence of an air conditioning operation.

2. The air conditioner according to claim 1,

the control unit performs control so that the next operation is executed for a predetermined period of time from the timing at which the operation is executed and before a 2 nd period longer than the 1 st period of time elapses.

3. The air conditioner according to claim 2,

the control unit performs control so as to start the next operation when the operation is executed, the 1 st period has elapsed, and a predetermined start condition is satisfied.

4. An air conditioner according to claim 3,

the starting condition is that the outdoor temperature of the outdoor unit is set to be less than a predetermined 1 st temperature threshold.

5. An air conditioner according to claim 3 or 4,

the starting condition is that the indoor temperature of the indoor unit is set to be less than a 2 nd predetermined temperature threshold value.

6. An air conditioner according to any one of claims 3 to 5,

the control unit determines whether the start condition is satisfied when the air-conditioning operation is stopped after the 1 st period has elapsed.

7. An air conditioner according to any one of claims 3 to 6,

the control unit performs control in the following manner: when it is determined that the start condition is not satisfied, the determination as to whether or not the start condition is satisfied is periodically repeated, and when it is not determined that the start condition is satisfied and a 3 rd period between the 1 st period and the 2 nd period has elapsed, the next operation is executed.

8. The air conditioner according to claim 7,

the control unit performs control so that the next operation is executed at a predetermined time in the nighttime when the 3 rd period has elapsed without determining that the start condition is satisfied.

9. An air conditioner according to any one of claims 1 to 8,

the control unit controls the opening degree of the expansion valve during operation according to the outdoor temperature of the outdoor unit.

10. An air conditioner according to claim 3,

when the operation is started, the control unit starts counting the period regardless of whether the operation is ended.

11. An air conditioner according to any one of claims 1 to 10,

the controller controls the outdoor fan so that the fins are dried by operating the outdoor fan after the operation is completed.