JP3233657B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which the temperature of hot air is controlled in accordance with the flow rate of an indoor fan.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner equipped with a general inverter, an operating frequency determined according to a difference between an actual room temperature and a set temperature is output from the inverter during operation and heating, so that a compressor is operated. The room temperature is controlled by changing the rotation speed. At that time, the temperature of the indoor heat exchanger is detected by a temperature sensor attached to the indoor heat exchanger, and the operating frequency of the inverter is controlled so that the temperature does not exceed a certain temperature (for example, 55 ° C.) The high pressure of the refrigeration cycle is kept within a predetermined range. In recent years,
In order to improve the comfort of heating by blowing hot air,
When the room temperature is lower than the set temperature, the operation frequency of the inverter is also controlled so that the temperature of the hot air blown out from the indoor unit becomes constant. On the other hand, the control of the air flow of the indoor fan that forcibly ventilates the indoor heat exchanger of the air conditioner involves changing the air flow sequentially according to the difference between the room temperature and the set temperature, or manually setting the desired air flow by the user. What you do is common.

[0003]

In the conventional air conditioner, the operating frequency of the inverter is controlled in accordance with the difference between the room temperature and the set temperature. The temperature of the exchanger exceeds 55 ° C., and in such a case, the temperature of the indoor heat exchanger is substantially controlled to be around 55 ° C. On the other hand, the air flow rate of the indoor fan is set by a difference between the room temperature and the set temperature or by a manual operation by the control panel regardless of the indoor heat exchanger temperature. Therefore, in such control, a change in the temperature of the hot air blown from the indoor fan corresponds to a case where the air flow of the indoor fan is changed while the temperature of the indoor heat exchanger is kept constant. That is, in FIG. 3, when the temperature of the indoor heat exchanger is kept constant irrespective of the air volume of the indoor fan as shown by a broken line a, the temperature of the hot air blown out is changed by the indoor fan as shown by a broken line b. Low when the air volume is large,
When the air volume is small, it becomes relatively high.

Therefore, when an actual indoor unit operates a wall-mounted air conditioner with a strong air flow of an indoor fan and a small air flow of a small air flow, the indoor temperature distribution is as shown in FIGS. 7 and 8, respectively. Become. If the air volume is large,
As shown in FIG. 7, the warm air reaches the floor surface, and the whole room is warmed by the circulation of air, so that no problem occurs. On the other hand, when the air volume is small at the same temperature of the indoor heat exchanger. As shown in FIG. 8, in addition to the weak wind, as shown in FIG. 3, the temperature of the hot air is high and the specific gravity thereof is relatively light as compared with the cold air in the room. And the cold air is not heated near the floor, in other words, there is a disadvantage that only the upper space in the room is heated. For this reason, there is an inconvenience that the comfort of heating is greatly reduced by the cooling sensation felt at the feet. Therefore, the present invention solves the above-mentioned problems of the prior art, and adjusts the blowing temperature of the hot air in accordance with the air volume so that the hot air reaches the floor, thereby improving the comfort of heating. It aims at providing a harmony machine.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned object, the present invention provides an indoor heat exchanger which is installed on an upper side wall surface of a room and has a variable amount of air flowing through the indoor heat exchanger. An air conditioner having a wall-mounted indoor unit having an inverter, changing an operating frequency by an inverter to control the number of rotations of the compressor, and controlling a heat exchanger temperature of the indoor heat exchanger. A hot air temperature detecting means for detecting a temperature of the hot air blown toward the indoor floor, and a high value of the hot air temperature when the set air flow of the indoor fan is large, and a set air flow of the indoor fan. Hot air temperature setting means for setting a hot air temperature of a lower value as the air temperature becomes smaller; hot air temperature detected by the hot air temperature detecting means; and hot air temperature set by the hot air temperature setting means. Comparing the door and it is characterized by comprising; and a frequency command means for increasing and decreasing command operation frequency in the inverter as the detected hot air temperature is set warm air temperature.

[0006]

[0007]

According to the present invention, the hot air temperature is set to a relatively low temperature when the air volume of the indoor fan is small, and to a high temperature when the air volume of the indoor fan is large. Since the operating frequency of the inverter is operated so as to eliminate the deviation, especially when the air volume of the indoor fan is small, the temperature of the hot air is kept relatively low and the hot air sufficiently reaches the floor.

[0008]

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the air conditioner according to the first aspect. The refrigeration cycle includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion valve 4, and an indoor heat exchanger 5. Is formed. The operating frequency of the compressor 1 is converted by the inverter 6 to control the rotation speed. Reference numeral 7 denotes an outdoor fan, and reference numeral 8 denotes a lateral flow type indoor fan. The indoor fan 8 controls the amount of air passing through the indoor heat exchanger 5 by operating the rotation speed of the indoor fan motor 8a. It can be changed to stages. In the air conditioner to which the present invention is applied, the indoor unit having the indoor heat exchanger 5 and the indoor fan 8 is:
As shown in FIG. 4, this is a so-called wall-mounted indoor unit that is used by being installed above a wall surface of a living room.

Next, in this air conditioner, a control unit 10 incorporating a microprocessor is provided in the indoor unit, and the control unit 10 includes an air volume setting unit 11 for setting the air volume of the indoor fan 8. A hot air temperature setting means 12 for setting a hot air temperature according to the current set air volume of the indoor fan 8.
Frequency command means for outputting a frequency increase / decrease command signal to the inverter 6 to operate the rotation speed of the compressor 1 so that the temperature of the hot air blown into the room becomes the temperature set by the hot air temperature setting means 12. 13 and the like.

Reference numeral 15 denotes a room temperature detector provided at an air suction port of the indoor unit. The room temperature Ta detected by the room temperature detector 15 is given to the air volume setting means 11.
The air volume setting means 11 sets the air volume of the indoor fan 8 based on the difference Ts-Ta between the set room temperature Ts input from the room temperature setter 16 and the room temperature Ta. In this case, the air volume is T
Although it is preferable to set the airflow in a stepwise manner in proportion to the magnitude of the difference value of s-Ta, in this embodiment, the set room temperature T
When the room temperature Ta is low and the temperature difference is large with respect to s, a predetermined large air volume (hereinafter, referred to as a strong wind) is set. It is to be set. Then, the air volume setting means 11 outputs an air volume setting signal to the indoor fan motor 8a, and based on the air volume setting signal, the indoor fan motor 8a rotates and the air volume of the indoor fan 8 is set to a strong wind or a breeze. The air volume setting means 11 outputs data on the air volume at this time to the hot air temperature setting means 12.

The hot air temperature setting means 12 sets a hot air temperature as a reference for controlling the hot air temperature based on the air volume data. In this case, the hot air temperature setting means 12
Sets a high value of the hot air temperature when the air volume of the indoor fan 8 is set to the strong wind, and sets a low value of the hot air temperature when the air volume of the indoor fan 8 is set to the light air volume. . Here, in the present embodiment, the temperature of the hot air is taken as the temperature of the indoor heat exchanger 5, that is, the temperature of the indoor heat exchanger 5, which is substantially proportional to the hot air temperature, is indirectly controlled as a direct control object. The hot air temperature is controlled in advance.
Therefore, the hot air temperature setting means 12 sets the set temperature for the indoor heat exchanger 5 to, for example, 55 ° C. when the air flow of the indoor fan 8 is strong wind, and 45 ° C. when the air flow is light wind. Set to ° C. Hereinafter, in the present embodiment, an example in which the temperature of the hot air is indirectly controlled by controlling the temperature of the indoor heat exchanger 5 based on the set temperature will be described. In addition, when the air volume of the indoor indoor fan 8 and the set temperature of the indoor heat exchanger 5 are set in multiple stages, it is preferable that the air volume is in a proportional relationship as shown by a straight line c in FIG.

The set temperature data set for the indoor heat exchanger 8 by the hot air temperature setting means 12 is introduced into the frequency command means 13 and the indoor heat exchanger temperature sensor 17 as a hot air temperature detecting means is introduced. Is introduced. The frequency command means 13 compares the set temperature with the indoor heat exchanger temperature Tc, and outputs an operating frequency increase / decrease command signal to the inverter 6 until the deviation disappears so that the indoor heat exchanger temperature Tc becomes the set temperature. . In FIG. 1, reference numeral 18 indicates ON / OFF control means.
The output of the room temperature detector 15 and the output of the room temperature setter 16 are given to the N / OFF control means 18, and the room temperature Ta
When the temperature becomes higher than s, an OFF signal for stopping the heating operation is output to the frequency command unit 13.

Next, the operation of this embodiment during the heating operation will be described with reference to FIG.
This will be described based on the flowchart of FIG. First, step S
At 1, the ON / OFF control means 18 controls the room temperature detector 1
5. Room temperature Ta taken from room temperature setting device 16,
Compared with the set room temperature Ts, when the room temperature Ta is higher than the set room temperature Ts, heating is not necessary, so the frequency command means 13 is used.
And the frequency command means 13 outputs a frequency command signal for setting the operation frequency to 0 Hz to the inverter 6 (step S2), and thereafter the heating operation is stopped.

On the other hand, when the room temperature Ta is lower than the set room temperature Ts in step S1, the heating operation is started based on the ON signal output from the ON / OFF control means 18. Then, the air volume setting means 11 sets the room temperature Ta and the set room temperature Ts.
The indoor fan 8 rotates at the airflow level of either strong wind or light wind set based on the difference between
Then, the process proceeds to the hot air temperature control of S7. That is, in step S3, the current set air volume of the indoor fan 8 is determined based on the air volume data given from the air volume setting means 11,
When it is set to a strong wind, the process proceeds to step S4. The hot air temperature setting means 12 sets 55 ° C. as the set temperature of the indoor heat exchanger 5 at this time. The frequency command means 13
The indoor heat exchanger temperature Tc is taken in from the indoor heat exchanger sensor 17, and when the indoor heat exchanger temperature Tc is lower than 55 ° C., a command signal for increasing the operating frequency is output to the inverter 6 (step S5), and the indoor heat exchange is performed. Vessel temperature Tc is 5
When the temperature is higher than 5 ° C., a command signal for decreasing the operation frequency is output to the inverter 6 (step S6). With such an operation frequency operation, when the air volume is set to a strong wind, the temperature of the indoor heat exchanger 5 is controlled so as to be maintained at 55 ° C. in due course.

On the other hand, in step S3, the current indoor fan 8
If the set air volume is a breeze, the process proceeds to step S7, where the hot air temperature setting means 12 sets 45 ° C. as the set temperature of the indoor heat exchanger 5 at this time. The frequency command means 13 outputs a frequency command signal for increasing or decreasing the operation frequency to the inverter 6 so that the temperature of the indoor heat exchanger 5 is maintained at 45 ° C. in the same manner as described above (steps S5 and S6).

With the above control, when the air volume is set to be large, the temperature of the indoor heat exchanger 5 is low (45 ° C.), and when the air volume is set to be large, the temperature of the indoor heat exchanger 5 is set to It is automatically adjusted to be kept high (55 ° C.). At this time, the temperature of the warm air actually blown out from the outlet of the indoor unit by the ventilation action of the indoor fan 8 is lower than the temperature of the indoor heat exchanger 8 as shown by a solid line d in FIG. Therefore, when the air volume is light, the warm air is kept relatively low. And FIG.
Is a schematic diagram showing the temperature distribution in the living space when the temperature of the indoor heat exchanger 8 is set to 45 ° C. under the setting of the amount of breeze in the present embodiment.
The actual hot air temperature is lower than 45 ° C., and the buoyancy caused by the specific gravity of the hot air being lighter than the cold air in the room is relatively suppressed, so that the temperature distribution near the floor surface is 20 ° C. to 25 ° C.
Warm air spreads to the floor to reach ℃, providing a comfortable heating effect.

Next, an embodiment of the present invention will be described with reference to FIGS. In FIG. 5, the refrigeration cycle is omitted because it is the same as that of the first embodiment, and only the control unit is denoted by the same reference numeral for the same component as that of the first embodiment. In this embodiment, a load-corresponding operating frequency determining means 20 for determining the operating frequency based on the air conditioning load is provided, and only when the hot air temperature exceeds the hot air temperature set in accordance with the air volume of the indoor fan 8, the frequency is adjusted. The command means 13 supplies a command signal to the inverter 6 to decrease the operating frequency of the inverter determined as described above.

In this embodiment, the load-dependent operating frequency determining means 20 determines the operating frequency of the inverter 6 using the room temperature detector 1.
The difference between the room temperature Ta detected by the step 5 and the set room temperature Ts given from the room temperature setting device 16 is determined based on this as a reference of the air conditioning load. Various methods such as proportional control, proportional integral control, and fuzzy control are known as methods for determining the operating frequency of the inverter 6, and various values such as humidity and refrigeration cycle pressure are also used as the reference of the air conditioning load. can do.

On the other hand, the air volume setting means 21
Is set to one of strong wind, medium wind and light wind based on the temperature difference between the set room temperature Ts and the room temperature Ta. In this case, the set air volume has a simple proportional relationship to the temperature difference. Then, the air volume setting means 21 supplies the set air volume data to the hot air temperature setting means 22 and outputs an air volume setting signal to the indoor fan motor 8a. The hot air temperature setting means 22 sets three levels of hot air temperature according to the input air volume data. Also in the second embodiment, the temperature of the hot air is detected through the indoor heat exchanger temperature sensor 17 as a hot air temperature detector, and the indoor heat exchanger temperature Tc is detected. The temperature of the exchanger 8 is directly controlled and the temperature of the hot air is controlled indirectly. Accordingly, the hot air temperature setting means 22 specifically sets the set temperature of the indoor heat exchanger 8 to, for example, 55 ° C. when the air volume of the indoor fan 8 is a strong wind,
When the air volume is medium, the temperature is 50 ° C.
Set to 5 ° C. The value of the set temperature and the magnitude of the air volume are determined to have a proportional relationship.

Then, the set temperature determined by the hot air temperature setting means 22, the indoor heat exchanger temperature Tc detected by the indoor heat exchanger sensor 17, and the operation of the inverter 6 determined by the load corresponding operation frequency determining means 20. Each of the frequencies f is input to the frequency command means 23. The frequency command means 13 firstly determines the current indoor heat exchanger temperature Tc,
The set temperatures are compared, and if the actual indoor heat exchanger temperature Tc is lower than the set temperature, a command signal for setting the operation frequency to the operation frequency f determined based on the air conditioning load is output to the inverter 6. On the other hand, when the indoor heat exchanger temperature Tc is higher than the set temperature, a command signal for decreasing the operation frequency stepwise from the current operation frequency at predetermined time intervals is output to the inverter 6.

Hereinafter, the control operation of this embodiment will be described with reference to the flowchart of FIG. When heating operation is started,
The indoor fan 8 is rotated at the airflow level set by the airflow setting means 21 based on the difference between the room temperature Ta and the set room temperature Ts, either strong wind, medium wind, or light wind.
The process shifts to hot air temperature control from 10 to S16.

First, in step S10, the load corresponding operating frequency determining means 20 calculates the difference between the room temperature Ta and the set room temperature Ts, and determines the operating frequency f of the inverter 6 from the result. Next, in step S11, the warm air temperature setting means 22 indirectly determines the current air volume of the indoor fan 8 from the rotation speed of the indoor fan 8, or determines the current indoor air volume from the air volume data given from the air volume setting device 21. The air volume of the fan 8 is determined, and the temperature of the indoor heat exchanger 8 corresponding to each air volume is set. If the air volume is light, the above set temperature is 4
When the temperature is 5 ° C., the process proceeds to the hot air temperature control in step S12. If the temperature is medium, the set temperature is 50 ° C. and the temperature is set to the hot air temperature control in step S13. Move to

Therefore, in step S12 when there is a breeze, the frequency command means 23 reads the indoor heat exchanger temperature Tc and compares the indoor heat exchanger temperature Tc with a set temperature of 45 ° C. When the indoor heat exchanger temperature Tc is equal to or lower than 45 ° C., the operation is performed at the operation frequency f determined in step S10 (step S15). On the other hand, when the indoor heat exchanger temperature Tc is higher than 45 ° C., since the hot air may not reach the floor, the process proceeds to step S16, and the operating frequency is decreased by 5 Hz from the operating frequency at that time. The operation frequency is maintained for one minute. After one minute, the indoor heat exchanger temperature Tc becomes 4
If the temperature is still higher than 5 ° C., the operation of outputting to the inverter 6 a frequency command signal for lowering the operation frequency by 5 Hz from the current operation frequency is repeated. By the operation of lowering the operating frequency in this manner, the indoor heat exchanger temperature Tc
Is maintained at 45 ° C. or less of the set temperature. The reason why the one-minute holding time is provided when the operating frequency of the inverter 6 is reduced is that the response time of the refrigeration cycle is large even if the operating frequency is reduced, and the indoor heat exchanger temperature Tc does not immediately decrease. This is because, when the operating frequency of the inverter 6 is reduced in a short time, the indoor heat exchanger temperature Tc, which is too large and decreases with a delay, is too low to prevent a hunting state.

Next, in step S13 for a moderate wind,
The indoor heat exchanger temperature Tc is compared with the set temperature of 50 ° C. If the indoor heat exchanger temperature Tc is equal to or lower than 50 ° C., the process proceeds to step S15, and if it is higher than 50 ° C., the process proceeds to step S16. Then, the operation frequency operation in steps S15 and S16 is executed in the same manner as in the case where the air volume is a light wind.

When the air volume is a strong wind, the same applies to step S1.
At 4, the indoor heat exchanger temperature Tc is compared with the set temperature of 55 ° C. If the indoor heat exchanger temperature Tc is equal to or lower than 55 ° C., the process proceeds to step S15, and if it is higher than 55 ° C., the process proceeds to step S16. In this case, in step S16, an operation of lowering the operating frequency is performed in order to prevent an increase in the high pressure of the refrigeration cycle, which is conventionally performed.

According to the second embodiment described above, the operating frequency f of the inverter 6 determined based on the load is the upper limit of the actual operating frequency. Specifically, in a range where the indoor heat exchanger temperature Tc does not exceed a set temperature determined in accordance with the air flow rate of the indoor fan 8, the operation is performed at the operation frequency f determined by the load corresponding operation frequency determination means 20. On the other hand, when the indoor heat exchanger temperature Tc exceeds the set temperature, the indoor heat exchanger 5 is operated at an operation frequency lower than the above operation frequency, and the temperature of the indoor heat exchanger 5 is maintained at the set temperature or lower. The temperature of the hot air is controlled to be equal to or lower than the set temperature. Therefore, when the air volume of the indoor fan 8 is small, the upper limit of the warm air temperature is controlled to be low, and the amount of warm air blown downward or obliquely downward can reach the floor surface, thereby increasing the comfort. A great heating effect can be obtained.

Since the temperature Tc of the indoor heat exchanger and the temperature of the hot air blown out are substantially proportional to each other, in the first and second embodiments described above, the temperature of the hot air is Although the temperature is indirectly detected as the temperature of the air conditioner, it is also possible to directly control the temperature of the hot air to the set temperature by providing another sensor and detecting the temperature of the hot air blown out of the air conditioner.

[0029]

As is apparent from the above description, according to the present invention, the hot air temperature is automatically maintained at a high or low temperature corresponding to the large or small air volume of the indoor fan. When the temperature is low, the warm air temperature is kept low, so the buoyancy of the blown hot air is relatively low, and the air volume is small, so even if the wind is weak, the warm air spreads to the floor and the heating is comfortable The performance is improved. For this reason, there is an advantage that a sufficient heating effect can be obtained even when the operation is performed while suppressing the noise under a relatively small air volume.

[0030]

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view showing a first embodiment of an air conditioner according to the present invention.

FIG. 2 is a flowchart showing an operation of hot air control according to the first embodiment.

FIG. 3 is a diagram showing a relationship between a temperature of an indoor heat exchanger and a temperature of a hot air, and an air volume of an indoor fan.

FIG. 4 is an explanatory diagram showing a temperature distribution in a room when the air conditioner of the present embodiment performs a heating operation with a small air flow.

FIG. 5 is a block diagram showing the configuration of a control unit in another embodiment of the air conditioner according to the present invention.

FIG. 6 is a flowchart showing the operation of hot air control according to the other embodiment.

FIG. 7 is an explanatory diagram showing a temperature distribution in a room when a heating operation is performed with a strong air flow rate in a conventional air conditioner.

FIG. 8 is an explanatory diagram showing a temperature distribution in a room when a heating operation is performed with a small air flow in a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Expansion valve 5 Indoor heat exchanger 6 Inverter 7 Outdoor fan 8 Indoor fan 10 Control part 11 Air volume setting means 12 Hot air temperature setting means 13 Frequency command means 15 Room temperature detector 16 Room temperature Setting device 17 Indoor heat exchanger temperature sensor 20 Operation frequency determining means corresponding to load

Claims (2)

(57) [Claims] 1. A wall-mounted indoor unit having an indoor heat exchanger and an indoor fan having a variable amount of air flowing through the indoor heat exchanger, which is installed on an upper side wall surface of the indoor room, and has an inverter to reduce the operating frequency. In the air conditioner, which controls the number of rotations of the compressor to control the heat exchanger temperature of the indoor heat exchanger, the temperature of the hot air blown out from the indoor unit toward the indoor floor by the indoor fan is detected. Hot air temperature detecting means,
Hot air temperature setting means for setting a high value of the hot air temperature when the set air volume of the indoor fan is large, and setting a low value of the hot air temperature as the set air volume of the indoor fan becomes small; The hot air temperature detected by the temperature detecting means is compared with the hot air temperature set by the hot air temperature setting means, and the detected hot air temperature is set to the set hot air temperature by the inverter. An air conditioner comprising: frequency command means for issuing a command to increase or decrease the operating frequency. 2. The air conditioner according to claim 1, wherein the hot air temperature detecting means detects the temperature of the indoor heat exchanger to thereby indirectly detect the temperature of the hot air blown out by the indoor fan. A characteristic air conditioner.