Air conditioning device

Abstract

The air conditioning device is provided with: a compressor; an outdoor fan; and a control device, which performs fan intermittent operation in which the operation and stop of the outdoor fan are repeated after the compressor is stopped, in the fan intermittent operation, in a case where the outdoor fan is operating and there is no snow accumulation to the outdoor fan, the control device changes the upper limit time of the stop of the outdoor fan according to the operating time of the outdoor fan in the fan intermittent operation, stops the operation of the outdoor fan after the upper limit time of the stop of the outdoor fan is changed, and causes the outdoor fan to operate in a case where the stop time of the outdoor fan exceeds the changed upper limit time of the stop.

Description

Technical Field

[0001] This disclosure relates to an air conditioning device that operates the fan intermittently. Background Technology

[0002] Heat pump air conditioning systems place the outdoor unit, equipped with an outdoor fan and an outdoor heat exchanger, outdoors to introduce heat from the air. When snowfall occurs while the outdoor fan is off, an increase in snow accumulation can disrupt its weight balance. When the outdoor fan restarts in this state, it may sometimes come into contact with surrounding structures such as the bell-shaped opening and break. Furthermore, snow accumulating on the outdoor fan can freeze between the fan and the structure, forming icicles. When the outdoor fan restarts, it may sometimes come into contact with these icicles, causing it to scrape and break.

[0003] Therefore, a technology has been proposed that prevents snow accumulation on the outdoor fan by intermittently operating the outdoor fan at regular intervals, even when the compressor is stopped (see, for example, Patent Document 1). In the technology described in Patent Document 1, the air conditioning device detects the outside air temperature and, when the outside air temperature is low, forces the outdoor fan to operate intermittently at regular intervals.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2003-232557 Summary of the Invention

[0007] However, in the technology disclosed in Patent Document 1, the air conditioning device will always keep the outdoor fan running at certain intervals when the outside air temperature is low, even when there is no snow accumulation on the outdoor fan and the fan does not need to run intermittently.

[0008] Therefore, traditional air conditioning systems have the problem of wasting electricity by intermittently running the outdoor fan after the compressor stops.

[0009] This disclosure was made in view of the above-mentioned actual situation, and its purpose is to provide an air conditioning device that can reduce the power consumption of the outdoor fan during intermittent operation after the compressor stops.

[0010] The air conditioning device disclosed herein includes: a compressor; an outdoor fan; and a control device that performs intermittent operation of the outdoor fan, repeating the operation and stopping of the outdoor fan after the compressor stops. During the intermittent operation, when the outdoor fan is operating and there is no snow accumulation on the outdoor fan, the control device changes the upper limit time for stopping the outdoor fan based on the operating time of the outdoor fan during the intermittent operation. After changing the upper limit time for stopping the outdoor fan, the control device stops the operation of the outdoor fan. If the stopping time of the outdoor fan exceeds the changed upper limit time for stopping, the control device enables the outdoor fan to operate.

[0011] According to this disclosure, in the absence of snow accumulation on the outdoor fan, the control device changes the upper limit of the outdoor fan's stop time based on the outdoor fan's operating time during intermittent operation, thereby stopping the outdoor fan's operation. The control device then restarts the outdoor fan if the stop time exceeds the changed upper limit. Therefore, the control device can extend the upper limit of the outdoor fan's stop time when there is no snow accumulation, the outdoor fan's operating time is short, and the possibility of outdoor fan damage is low. This reduces the power consumption of the air conditioning unit. Attached Figure Description

[0012] Figure 1 This is a schematic diagram showing the interior of the outdoor unit of the air conditioning device in Embodiment 1 from the front.

[0013] Figure 2 This is a diagram showing the structure of the control system of the air conditioning device according to Embodiment 1.

[0014] Figure 3 This is a flowchart illustrating the actions performed before and after the intermittent operation of the fan in the air conditioning device of Embodiment 1 begins.

[0015] Figure 4 This is a flowchart illustrating the operation of the fan in the air conditioning device of Embodiment 1 during intermittent operation.

[0016] Figure 5 This is a graph showing the changes in the operating time and stopping time of the outdoor fan during intermittent operation of the air conditioning device according to Embodiment 1.

[0017] Figure 6 This is a diagram showing the structure of the control system of the air conditioning device according to Embodiment 2.

[0018] Figure 7 This is a flowchart illustrating the operation of the fan in the air conditioning device of Embodiment 2 during intermittent operation.

[0019] Figure 8This is a diagram showing the structure of the control system of the air conditioning device according to Embodiment 3.

[0020] Figure 9 This is a flowchart illustrating the operation of the fan in the air conditioning device of Embodiment 3 during intermittent operation.

[0021] Figure 10 This is a diagram showing the structure of the control system of the air conditioning device according to Embodiment 4.

[0022] Figure 11 This is a flowchart illustrating the operation of the air conditioning device fan during intermittent operation in Embodiment 4.

[0023] (Explanation of symbols)

[0024] 1: Outdoor fan; 2: Outdoor heat exchanger; 3: Compressor; 4: Control device; 4a: Timer; 5: External air temperature detector; 6: Snow accumulation detector; 7: Power detector; 8: Current detector; 9: Voltage detector; 100: Air conditioning unit; A: Outdoor unit; To: First external air temperature threshold; To_1: Second external air temperature threshold; C1, C2, C3, C4: Cycle; t1, t2, t3, t4: Stop time; t_off: Upper limit time for fan stop; tc: Decision time; Ic: Current decision value. Detailed Implementation

[0025] Hereinafter, an air conditioning device according to an embodiment will be described with reference to the accompanying drawings. Furthermore, in the drawings, the same reference numerals are used to describe the same structural elements, and descriptions are repeated only where necessary. This disclosure may include all combinations of the structures that can be combined in the following embodiments.

[0026] Implementation method 1.

[0027] Figure 1 This is a schematic diagram showing the interior of the outdoor unit A of the air conditioning device 100 in Embodiment 1 from the front. The outdoor unit A includes an outdoor fan 1, an outdoor heat exchanger 2, a compressor 3, and a control device 4.

[0028] The outdoor heat exchanger 2 is connected to the compressor 3 and the indoor unit (not shown) via refrigerant piping.

[0029] Compressor 3 compresses the refrigerant flowing through the refrigerant piping. Outdoor fan 1 blows air for heat exchange. Control unit 4 manages the overall control of outdoor unit A.

[0030] Furthermore, in this embodiment 1, a structure in which one outdoor fan 1 is mounted on one outdoor unit A is described as an example, but the number of outdoor fans 1 is not limited to one; it can be two or more. In addition, the blowing direction of the outdoor fan 1 is not limited to blowing towards the front (horizontal direction) of the outdoor unit A; it can also blow towards the top (upward direction) of the outdoor unit A.

[0031] Furthermore, the structure in which the compressor 3 and the control device 4 are mounted on the outdoor unit A is used as an example for explanation, but it is not limited to the structure in which the compressor 3 and the control device 4 are mounted on the outdoor unit A; it can also be a structure in which the compressor 3 and the control device 4 are installed indoors.

[0032] Figure 2 This is a diagram showing the structure of the control system of the air conditioning device 100 according to Embodiment 1.

[0033] The control device 4 includes dedicated hardware or a CPU (Central Processing Unit, also known as a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or processor) that executes programs stored in memory.

[0034] When the control device 4 is dedicated hardware, the control device 4 is, for example, equivalent to a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each functional part of the control device 4 can be implemented by a separate piece of hardware, or each functional part can be implemented by a single piece of hardware.

[0035] When the control device 4 is a CPU, the functions to be performed by the control device 4 are implemented by software, firmware, or a combination of software and firmware. The software and firmware are described as programs and stored in memory. The CPU implements the functions of the control device 4 by reading and executing the programs stored in memory. Here, the memory is, for example, non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, EEPROM, etc.

[0036] Alternatively, some of the functions of the control device 4 can be implemented using dedicated hardware, while other parts can be implemented using software or firmware.

[0037] The control device 4 includes a timer 4a. The timer 4a measures the operating time and stopping time of the outdoor fan 1 in the intermittent fan operation mode. Here, the intermittent fan operation mode is a mode in which the outdoor fan 1 operates and stops repeatedly after the compressor 3 stops.

[0038] The control device 4 is connected to the external air temperature detector 5 and the snow accumulation detector 6 via signal lines. The control device 4 receives information from the external air temperature detector 5 and the snow accumulation detector 6. The control device 4 is also connected to the outdoor fan 1 and the compressor 3 via signal lines. The control device 4 outputs control signals to the outdoor fan 1 and the compressor 3 via signal lines. Specifically, the control device 4 controls the speed of the outdoor fan 1 and the operating frequency of the compressor 3 according to the operating mode set for the air conditioning unit 100.

[0039] External air temperature detector 5 detects the external air temperature.

[0040] The snow detection device 6 detects the snow accumulation on the outdoor fan 1. The snow detection device 6 may have, for example, a camera capable of image recognition of the appearance of the outdoor fan 1, and detects the thickness and distribution of the snow accumulation based on the images captured by the camera.

[0041] The snow detection device 6 may also have a weight detector capable of detecting the weight of the outdoor fan 1. The snow detection device 6 may also detect the snow accumulation status by detecting the difference between the weight of the outdoor fan 1 detected by the weight detector and the weight of the outdoor fan 1 in a state without snow accumulation.

[0042] The snow detection device 6 may also have a photodetector capable of distinguishing colors by detecting light from a light source and reflected light from the surface of the outdoor fan 1. The snow detection device 6 may also use the surface of the outdoor fan 1 as a color other than white and detect the snow accumulation status by utilizing the fact that only the snow-covered parts turn white.

[0043] Furthermore, the snow accumulation detection device 6 may also have a power detector capable of detecting the axial force of the outdoor fan 1. Regarding the axial force detected by the power detector, snow accumulates on the outdoor fan 1, thus increasing its weight and axial force. The snow accumulation detection device 6 detects the snow accumulation state by detecting the difference between the increased axial force and the axial force in the state without snow accumulation.

[0044] Next, the operating characteristics of the various operations performed by the air conditioning device 100 of Embodiment 1 will be explained.

[0045] The air conditioning unit 100 has two operating modes: heating operation and intermittent fan operation.

[0046] During heating operation, control device 4 activates both the outdoor fan 1 and the compressor 3. By activating compressor 3, control device 4 transforms the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant, which is then delivered from outdoor unit A to indoor unit to heat the indoor air, thus providing heating. Meanwhile, in indoor unit, the high-temperature, high-pressure gaseous refrigerant is cooled by the indoor air and transforms into a low-temperature liquid refrigerant.

[0047] Control device 4 converts the liquid refrigerant into a low-temperature, low-pressure two-phase refrigerant by adjusting the valve opening of a pressure-reducing device (not shown), which then flows into the outdoor heat exchanger 2. Control device 4 then operates the outdoor fan 1, causing heat exchange between the outdoor air and the refrigerant in the outdoor heat exchanger 2. The outdoor air heats the two-phase refrigerant, converting it into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant returns to the compressor 3, becoming usable again for heating.

[0048] When the heating is running, the outdoor fan 1 operates, so even if it snows, snow will not accumulate on the outdoor fan 1, and there is no need to worry about damage.

[0049] When heating operation stops, there is no need to send refrigerant to the indoor unit, so control device 4 stops compressor 3. Furthermore, since there is no need for heat exchange between outdoor air and refrigerant, control device 4 also stops outdoor fan 1. When outdoor fan 1 is stopped, snow may accumulate on it during snowfall, potentially causing damage. Therefore, control device 4 implements intermittent fan operation to prevent snow accumulation on outdoor fan 1.

[0050] When the fan operates intermittently, the control device 4 repeats the operation and shutdown of the outdoor fan 1. The control device 4 causes the outdoor fan 1 to operate intermittently, thereby suppressing snow accumulation on the outdoor fan 1.

[0051] [Actions performed before and after the fan stops running intermittently]

[0052] Figure 3 This is a flowchart illustrating the actions taken before and after the intermittent operation of the fan in the air conditioning device 100 of Embodiment 1 begins.

[0053] Control device 4 determines whether compressor 3 has stopped (step S1). If control device 4 determines that compressor 3 has not stopped (no in step S1), it implements normal operation control (step S2) and ends the process.

[0054] On the other hand, when the control device 4 determines that the compressor 3 has stopped (in step S1), it determines whether the external air temperature is below the first external air temperature threshold To at the start of intermittent fan operation (in step S3).

[0055] If the control device 4 determines that the external air temperature is higher than the first external air temperature threshold To (No in step S3), it stops operation (step S4) and ends the process.

[0056] On the other hand, when the control device 4 determines that the outside air temperature is below the first outside air temperature threshold To, it implements intermittent fan operation (step S5). During the intermittent fan operation, the control device 4 determines whether the compressor 3 has started operating (step S6).

[0057] When the control device 4 determines that the compressor 3 has started working (in step S6), it performs normal operation (in step S2) and ends the process.

[0058] On the other hand, if the control device 4 determines that the compressor 3 has not started working (No in step S6), it determines whether the external air temperature is higher than the second external air temperature threshold To_1 when the fan intermittent operation ends (step S7).

[0059] If the control device 4 determines that the external air temperature is higher than the second external air temperature threshold To_1 (in step S7), it will stop operation (in step S4) and end the process.

[0060] On the other hand, if the control device 4 determines that the external air temperature is below the second external air temperature threshold To_1 (No in step S7), it causes the fan to continue to operate intermittently (step S5).

[0061] In addition, Figure 3 In this configuration, the control device 4 immediately initiates intermittent fan operation when the compressor 3 stops and the external air temperature is lower than the first external air temperature threshold To at the start of intermittent fan operation, but is not limited to this. For example, the control device 4 may also initiate intermittent fan operation of the outdoor fan 1 after a certain period of time has elapsed since the compressor 3 stopped.

[0062] If the compressor 3 stops not due to a user-initiated shutdown but because the room temperature reaches the target value, it may restart shortly, making intermittent fan operation unnecessary. Therefore, the control device 4 can be set to operate for a certain period from the time the compressor 3 stops until the intermittent fan operation begins. This allows the control device 4 to avoid unnecessary intermittent fan operation.

[0063] In addition, Figure 3 Before the fan operates intermittently, the compressor is determined in step S1, and then the outside air temperature is determined in step S3. However, this order is arbitrary, and the compressor determination can also be performed after the outside air temperature determination. The same applies when the fan stops operating intermittently.

[0064] [Control during intermittent fan operation]

[0065] Figure 4 This is a flowchart illustrating the operation of the fan of the air conditioning device 100 in Embodiment 1 during intermittent operation. Figure 4 Detailed Explanation Figure 3 The action of step S5.

[0066] Control device 4 determines whether outdoor fan 1 is working during intermittent operation of the fan (step S10). If control device 4 determines that outdoor fan 1 is not working (no in step S10), it proceeds to step S11; if it determines that outdoor fan 1 is working (yes in step S10), it proceeds to step S15.

[0067] In step S11, control device 4 counts the fan stop time. Then, control device 4 determines whether the fan stop time is less than the upper limit of fan stop time t_off (step S12). If control device 4 determines that the fan stop time is greater than or equal to the upper limit of fan stop time t_off, it resets the fan stop time (step S13). Then, control device 4 starts the outdoor fan 1 (step S14).

[0068] If the control device 4 determines that the fan stop time is less than the upper limit of the fan stop time t_off (as determined in step S12), it stops the fan from continuing.

[0069] On the other hand, in step S15, the control device 4 counts the fan operating time. Then, the control device 4 determines whether there is snow accumulating on the outdoor fan 1 based on the snow accumulation status input from the snow accumulation detection device 6 (step S16).

[0070] If the control device 4 determines that there is no snow accumulation on the outdoor fan 1 (No in step 16), it determines whether the fan operating time is less than the determination time tc (step S17). If the control device 4 determines that the fan operating time is greater than or equal to the determination time tc (No in step S17), it reduces the upper limit of the fan stop time t_off (step S18). Alternatively, the control device 4 can also make the upper limit of the fan stop time t_off shorter the longer the fan operating time.

[0071] On the other hand, if the control device 4 determines that the fan operating time is less than the determination time tc (in step S17), it increases the upper limit time t_off for the fan stop (in step S19). Alternatively, the control device 4 can also make the upper limit time t_off for the fan stop longer if the fan operating time is shorter.

[0072] After step S18 or step S19, control device 4 resets the fan operating time (step S20) and stops outdoor fan 1 (step S21). If control device 4 determines in step S16 that there is snow accumulation on outdoor fan 1 (yes in step S16), it allows outdoor fan 1 to continue operating.

[0073] Control device 4 determines whether the end condition for intermittent fan operation is met (step S22) when the condition is met in step S16, after step S21, when the condition is met in step S12, and after step S14. Here, the conditions under which the "end condition for intermittent fan operation" is met include... Figure 3 In step S6, the control device 4 determines that the compressor 3 has started working (step S6 is yes) or in step S7, the control device 4 determines that the external air temperature is higher than the second external air temperature threshold To_1 at the end of the fan intermittent operation (step S7 is yes).

[0074] If the control device 4 determines that the end condition for intermittent fan operation is met (yes in step S22), it terminates the intermittent fan operation. If the control device 4 determines that the end condition for intermittent fan operation is not met (no in step S22), it returns to step S10 and allows the intermittent fan operation to continue.

[0075] Here, the effects of steps S16 to S19 are explained, which determine whether there is snow accumulation on the outdoor fan 1 and cause the fan to stop for an upper limit time t_off according to the fan's operating time. Figure 5 This is a graph showing the changes in the operating time and stopping time of the outdoor fan 1 during intermittent operation of the air conditioning device 100 in Embodiment 1.

[0076] Figure 5 The vertical axis represents the operating and stopping state of outdoor fan 1, and the horizontal axis represents time. Furthermore, Figure 5 The numbers C1 through C4 in the diagram represent the number of cycles of operation and stoppage. One cycle is defined as the period from the start of operation to the end of stoppage. Cycle C1 represents the first cycle, cycle C2 the second, C3 the third, and C4 the fourth. However, cycle C1 is not limited to the first cycle after the fan begins intermittent operation; it represents the first cycle shown in the diagram. Figure 5 The values ​​t1, t2, t3, and t4 shown represent the stopping times of each loop. Time t1 represents the stopping time of loop C1, time t2 represents the stopping time of loop C2, time t3 represents the stopping time of loop C3, and time t4 represents the stopping time of loop C4.

[0077] Reference Figure 5It can be seen that the stopping times t1, t2, t3, and t4 vary depending on the operating time of each cycle C1, C2, C3, and C4 during the intermittent operation of the fan in the air conditioning unit 100. In cycle C2, the operating time is shorter than the decision time tc, so the stopping time t2 of cycle C2 is longer than the stopping time t1 of cycle C1. Similarly, in cycle C3, the operating time is also shorter than the decision time tc, so the stopping time t3 of cycle C3 is also longer than the stopping time t2 of cycle C2. On the other hand, in cycle C4, the operating time is longer than the decision time tc, so the stopping time t4 of cycle C4 is shorter than the stopping time t3 of cycle C3.

[0078] In this way, the decision to keep the fan running or stop it is based on the presence or absence of snow, thus varying the fan operating time according to the snow conditions. When there is little snowfall and little snow accumulation on the fan, the operating time can be shortened. In this case, the likelihood of snow accumulating again after the fan stops is low, so the fan can be stopped for a longer period, thereby reducing unnecessary fan operation and cutting power consumption.

[0079] In addition, Figure 4 In this process, the determination time tc is 1. In steps S17 to S19, the upper limit of the fan stop time t_off is increased or decreased based on the relationship between the fan operating time and the determination time tc. However, steps S17 to S19 can also be set so that the upper limit of the fan stop time t_off remains unchanged. For example, determination times tc1 and tc2 can be set such that tc1 < tc2. When the fan operating time is less than or equal to the determination time tc1, the control device 4 increases the upper limit of the fan stop time t_off. When the fan operating time is greater than or equal to the determination time tc2, the control device 4 decreases the upper limit of the fan stop time t_off. When the fan operating time is between the determination time tc1 and the determination time tc2, the control device 4 does not change the upper limit of the fan stop time t_off.

[0080] Furthermore, the control device 4 can also be configured with multiple decision times tc, allowing the magnitude of the increase or decrease in the upper limit of the fan stop time t_off to be variable. For example, decision times tc1 and tc2 can be set, with tc1 < tc2. When the fan operating time is less than or equal to decision time tc1, the control device 4 increases the upper limit of the fan stop time t_off. When the fan operating time is greater than or equal to decision time tc1, the upper limit of the fan stop time t_off is decreased. When the fan operating time is greater than or equal to decision time tc2, the decrease in the upper limit of the fan stop time t_off is increased compared to the case where the fan operating time is between decision times tc1 and tc2.

[0081] Alternatively, steps S17 to S19 can be replaced by calculating the upper limit of the fan stop time t_off based on the fan operating time. By using a formula where the longer the fan operating time, the smaller the upper limit of the fan stop time t_off, the same effect as steps S17 to S19 can be obtained.

[0082] In addition, Figure 4 In step S15, the fan operating time is counted, and then in step S16, it is determined whether there is snow accumulation. However, this order is arbitrary; it is also possible to determine whether there is snow accumulation and decide to continue fan operation before counting the fan operating time. The same applies to counting the fan stop time; it is possible to count the fan stop time after deciding to continue fan operation.

[0083] In addition, it can also be done at the start of intermittent fan operation. Figure 4 Before step S10, add a step to specify which outdoor fan 1 should be stopped or started.

[0084] Implementation method 2.

[0085] Figure 6 This is a diagram showing the structure of the control system of the air conditioning device 100 according to Embodiment 2.

[0086] Hereinafter, the description will focus on the parts of the air conditioning device 100 of Embodiment 2 that are different from those of Embodiment 1, and detailed descriptions of the same structure and operation as in Embodiment 1 will be omitted.

[0087] In this embodiment 2, the control system of the air conditioning device 100 is replaced. Figure 2 The air conditioning unit 100 of Embodiment 1 shown is equipped with a power detector 7 instead of a snow accumulation detection device 6. The power detector 7 detects the power consumption of the outdoor fan 1.

[0088] In the air conditioning device 100 of Embodiment 2, the power consumption of the outdoor fan 1, detected by the power detector 7, is used to determine whether the fan operation should continue or stop during intermittent operation. When there is snow accumulation on the outdoor fan 1, the weight of the outdoor fan 1 increases, so the power required to operate the outdoor fan 1 at the same speed increases. Therefore, compared to the case without snow accumulation, the power consumption of the outdoor fan 1 increases, and by detecting the increase in power consumption by the power detector 7, it is possible to determine whether there is snow accumulation on the outdoor fan 1.

[0089] [Control during intermittent fan operation]

[0090] Figure 7This is a flowchart illustrating the operation of the fan in the air conditioning device 100 of Embodiment 2 during intermittent operation. Furthermore, in the following description, the parts that differ from the flowchart of the fan during intermittent operation in Embodiment 1 will be explained.

[0091] Steps S30 to S35 and Figure 4 Steps S10 to S15 are the same. After step S35, the control device 4 determines whether the power consumption of the outdoor fan 1 detected by the power detector 7 is greater than the power consumption determination value Pc (step S36). If the control device 4 determines that the power consumption of the outdoor fan 1 is less than the power consumption determination value Pc (no in step S36), the control device 4 determines whether the fan operating time is less than the determination time tc (step S37). Steps S37 to S41 are the same as... Figure 4 Steps S17 to S21 are the same. In steps S37 to S39, the control device 4 sets the upper limit time t_off for the fan to stop according to the fan operating time. Then, the control device 4 resets the fan operating time (step S40) and stops the outdoor fan 1 (step S41).

[0092] On the other hand, in step S36, if the control device 4 determines that the power consumption of the outdoor fan 1 is greater than the power consumption determination value Pc (in step S36), the fan continues to operate.

[0093] The control device 4 determines whether to continue or stop the operation of the outdoor fan 1 by judging the relationship between the power consumption of the outdoor fan 1 and the power consumption determination value Pc in step S36. Therefore, the operating time of the outdoor fan 1 is changed, so the same effect as steps S17 to S19 in Embodiment 1, which change the upper limit time t_off of the fan stop, can be obtained.

[0094] Step S42 and Figure 4 The steps shown in step S22 are the same.

[0095] Furthermore, the power consumption of outdoor fan 1 varies depending on its rotational speed, so by adjusting the power consumption judgment value Pc according to the rotational speed, the judgment can be made more accurately. Moreover, even at the same rotational speed, power consumption varies depending on the settings of outdoor unit A, so by detecting the power consumption during heating operation and adjusting the power consumption judgment value Pc accordingly, the judgment can be made more accurately.

[0096] Implementation method 3.

[0097] Figure 8 This is a diagram showing the structure of the control system of the air conditioning device 100 according to Embodiment 3.

[0098] Hereinafter, the description will focus on the parts of the air conditioning device 100 of Embodiment 3 that are different from those of Embodiment 1, and detailed descriptions of the same structure and operation as in Embodiment 1 will be omitted.

[0099] In this embodiment 3, the control system of the air conditioning device 100 is replaced. Figure 2 The air conditioning unit 100 of Embodiment 1 shown is equipped with a current detector 8 instead of a snow detection device 6. The current detector 8 detects the current flowing through the outdoor fan 1.

[0100] In the air conditioning unit 100, the current flowing through the outdoor fan 1, detected by the current detector 8, is used to determine whether to continue or stop the intermittent operation of the outdoor fan 1. When there is snow accumulation on the outdoor fan 1, the weight of the outdoor fan 1 increases. Therefore, the power required for the control device 4 to operate the outdoor fan 1 at the same speed increases. Consequently, the current to the outdoor fan 1 at the same speed increases compared to the case without snow accumulation. The current detector 8 detects the current flowing to the outdoor fan 1. The control device 4 determines whether there is snow accumulation on the outdoor fan 1 based on the current flowing to the outdoor fan 1 detected by the current detector 8.

[0101] [Control during intermittent fan operation]

[0102] Figure 9 This is a flowchart illustrating the operation of the fan in the air conditioning device 100 of Embodiment 3 during intermittent operation. Furthermore, the following description will explain the parts that differ from the operation of the fan during intermittent operation in Embodiment 2 described above.

[0103] Steps S50 to S55 and Figure 4 Steps S10 to S15 are the same. In step S56, the control device 4 determines whether the current of the outdoor fan 1 detected by the current detector 8 is greater than the current determination value Ic. In step S56, if the control device 4 determines that the current of the outdoor fan 1 is less than the current determination value Ic (no in step S56), the control device 4 determines whether the fan operating time is less than the determination time tc (step S57). Steps S57 to S61 are the same as... Figure 4 Steps S17 to S21 are the same. In steps S57 to S59, control device 4 sets the upper limit time t_off for the fan to stop according to the fan operating time. Control device 4 then resets the fan operating time (step S60). Next, control device 4 stops the outdoor fan 1 (step S61).

[0104] On the other hand, in step S56, if the control device 4 determines that the current of the outdoor fan 1 is greater than the current determination value Ic (in step S56), the control device 4 enables the outdoor fan 1 to continue operating.

[0105] By determining the relationship between the current of the outdoor fan 1 and the current determination value Ic in step S56, the control device 4 decides whether to continue or stop the operation of the outdoor fan 1. Therefore, changing the operating time of the outdoor fan 1 can achieve the same effect as steps S17 to S19 in Embodiment 1, which change the upper limit time t_off for fan stopping.

[0106] Step S62 and Figure 4 The steps shown in step S22 are the same.

[0107] Furthermore, the current of outdoor fan 1 varies with its rotational speed, so by adjusting the current determination value Ic according to the speed, a more accurate determination can be made. Additionally, even at the same rotational speed, the current varies depending on the settings of outdoor unit A, so by detecting the current during heating operation and adjusting the current determination value Ic accordingly, a more accurate determination can be made.

[0108] Implementation method 4.

[0109] Figure 10 This is a diagram showing the structure of the control system of the air conditioning device 100 according to Embodiment 4.

[0110] Hereinafter, the description will focus on the parts of the air conditioning device 100 of Embodiment 4 that are different from those of Embodiment 1, and detailed descriptions of the same structure and operation as in Embodiment 1 will be omitted.

[0111] In this embodiment 4, the control system of the air conditioning device 100 is replaced. Figure 2 The air conditioning unit 100 of Embodiment 1 shown is equipped with a voltage detector 9 in addition to the snow accumulation detection device 6. The voltage detector 9 detects the voltage applied to the outdoor fan 1.

[0112] In the air conditioning unit 100, the current flowing through the outdoor fan 1, detected by the current detector 8, is used to determine whether the fan operation should continue or stop during intermittent operation. When there is snow accumulation on the outdoor fan 1, its weight increases. Therefore, the power required for the control device 4 to operate the outdoor fan 1 at the same speed increases. Consequently, the voltage of the outdoor fan 1 at the same speed increases compared to the case without snow accumulation. The control device 4 determines whether there is snow accumulation on the outdoor fan 1 based on the voltage detected by the voltage detector 9.

[0113] [Control during intermittent fan operation]

[0114] Figure 11This is a flowchart illustrating the operation of the fan in the air conditioning device 100 of Embodiment 4 during intermittent operation. Furthermore, the following description will explain the parts that differ from the operation of the fan during intermittent operation in Embodiment 2 described above.

[0115] Steps S70 to S75 and Figure 4 Steps S10 to S15 are the same. In step S76, the control device 4 determines whether the voltage of the outdoor fan 1 detected by the voltage detector 9 is greater than the voltage determination value Vc. In step S76, if the control device 4 determines that the voltage of the outdoor fan 1 is less than the voltage determination value Vc (no in step S76), the control device 4 determines whether the fan operating time is less than the determination time tc (step S77). Steps S77 to S81 are the same as... Figure 4 Steps S17 to S21 are the same. In steps S77 to S79, control device 4 sets the upper limit time t_off for the fan to stop according to the fan operating time. Control device 4 then resets the fan operating time (step S80). Next, control device 4 stops the outdoor fan 1 (step S81).

[0116] On the other hand, in step S76, if the control device 4 determines that the voltage of the outdoor fan 1 is greater than the voltage determination value Vc (in step S76), the control device 4 enables the outdoor fan 1 to continue operating.

[0117] By determining the relationship between the voltage of the outdoor fan 1 and the voltage determination value Vc in step S76, the control device 4 decides whether to continue or stop the operation of the outdoor fan 1. Therefore, the operating time of the outdoor fan 1 changes, thus achieving the same effect as steps S17 to S19 in Embodiment 1, which change the upper limit time t_off for fan stopping.

[0118] Step S82 and Figure 4 The steps shown in step S22 are the same.

[0119] (1) The air conditioning device 100 according to Embodiment 1, Embodiment 2, Embodiment 3 and Embodiment 4 has the following effects.

[0120] When there is no snow accumulation on the outdoor fan 1, the control device 4 stops the outdoor fan 1 by adjusting the upper limit of its stop time based on the operating time of the outdoor fan 1 during intermittent operation. Furthermore, if the stop time of the outdoor fan 1 exceeds the adjusted upper limit of its stop time, the control device 4 restarts the outdoor fan 1. Therefore, when there is no snow accumulation, the operating time of the outdoor fan 1 is short, and the possibility of damage to the outdoor fan 1 is low, the control device 4 can extend the upper limit of the stop time of the outdoor fan 1. This reduces the power consumption of the air conditioning unit 100. Furthermore, it prevents the outdoor fan 1 from being damaged due to snow accumulation.

[0121] (2) The air conditioning device 100 according to Embodiment 2, Embodiment 3 and Embodiment 4 has the following effects.

[0122] The control device 4 determines the state of snow accumulation based on the power consumption of the outdoor fan 1, the current flowing through the outdoor fan 1, and the voltage applied to the outdoor fan 1. Therefore, it can determine whether there is snow accumulation at a lower cost than the snow detection device 6 of Embodiment 1.

[0123] The power consumption judgment value Pc, the current judgment value Ic, and the voltage judgment value Vc are set based on the rotational speed of the outdoor fan 1. Therefore, by taking into account the power consumption of the outdoor fan 1, the current flowing through the outdoor fan 1, and the changes in the voltage applied to the outdoor fan 1, the control device 4 can make more accurate judgments.

[0124] Furthermore, by taking into account the power consumption of the outdoor fan 1, the current flowing through the outdoor fan 1, and the voltage applied to the outdoor fan 1 based on the installation environment of the outdoor fan 1, a more accurate determination can be made.

[0125] Furthermore, in the above-described embodiments 1, 2, 3, and 4, an air conditioning device 100 that only operates in heating mode and intermittently operates the fan was used as an example, but it is not limited thereto. The air conditioning device 100 of the embodiments can also be applied to air conditioning devices 100 with circuit structures capable of cooling operation.

[0126] Furthermore, the snow detection device 6, the power detector 7, and the current detector 8 in the embodiments are also referred to as detection devices.

[0127] The embodiments are given by way of example and are not intended to limit the claims. Embodiments can be implemented in a wide variety of other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the embodiments. These embodiments and their variations are included within the scope and spirit of the embodiments.

Claims

1. An air conditioning device, comprising: compressor; Outdoor fans; and The control device performs intermittent operation of the outdoor fan after the compressor stops, repeating the operation of the fan when it stops. During the intermittent operation of the fan, when the outdoor fan is working and there is no snow accumulation on the outdoor fan, the control device changes the upper limit of the outdoor fan's stop time according to the working time of the outdoor fan during the intermittent operation. After changing the upper limit of the outdoor fan's stop time, the outdoor fan stops working. If the stop time of the outdoor fan exceeds the changed upper limit of the stop time, the control device makes the outdoor fan work again.

2. The air conditioning device as claimed in claim 1, wherein, The air conditioning unit includes a timer that measures the operating time of the outdoor fan during intermittent operation and the stopping time of the outdoor fan. The control device determines the upper limit of the outdoor fan's shutdown time based on the operating time of the outdoor fan measured by the timer.

3. The air conditioning device as described in claim 2, wherein, The control device determines the upper limit time for stopping the outdoor fan in such a way that the shorter the working time measured by the timer, the longer the upper limit time for stopping the outdoor fan.

4. The air conditioning device according to any one of claims 1 to 3, wherein, The air conditioning unit includes a detection device that detects the state of snow accumulation directed towards the outdoor fan. If the control device determines that there is snow accumulation on the outdoor fan during its intermittent operation, based on the snow accumulation detected by the detection device, the outdoor fan will continue to operate.

5. The air conditioning device as claimed in claim 4, wherein, The detection device detects any one of the following: the power consumption of the outdoor fan while it is in operation, the current flowing through the outdoor fan, and the voltage applied to the outdoor fan.

6. The air conditioning device as claimed in claim 5, wherein, The control device stops the outdoor fan if any one of the following detected by the detection device—the power consumption of the outdoor fan, the current flowing through the outdoor fan, and the voltage applied to the outdoor fan—is less than a threshold.

7. The air conditioning device as claimed in claim 6, wherein, The threshold is set based on the rotational speed of the outdoor fan.

8. The air conditioning device as claimed in claim 6, wherein, The threshold is determined based on any one of the following: the power consumption of the outdoor fan detected by the detection device when the compressor is running, the current flowing through the outdoor fan, and the voltage applied to the outdoor fan.

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