JPH063314B2 - Air conditioner - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an air conditioner in which a plurality of indoor units arranged in the same room are connected to an outdoor unit having a compressor whose capacity is controllable.

[Technical background of the invention and its problems]

The indoor shape is long and narrow, and in a crowded store (boutique, bar, etc.) or vehicle, the temperature inside the room is large, and even if air conditioning is performed, it will be about 4 to 4 at the end and the center.
A temperature difference of 5 ° C. may occur.

This is due to the fact that the air conditioning load differs in the longitudinal direction, the uneven distribution of the blown air, etc., and it is conceivable to employ a sophisticated duct system to keep the temperature difference low. However, this method has the drawback that the construction cost rises significantly and that it is difficult to control the air volume.

Therefore, as shown in FIG. 6, small capacity air conditioners composed of outdoor units 3na (n = 1 to 4) and indoor units 3nb (n = 1 to 4) are dispersed in the longitudinal direction of the elongated store 30. The method was adopted.

However, this method is disadvantageous in that it requires a large installation space for the outdoor unit 3na and further increases noise and power consumption.

Therefore, a so-called "one-room multi-air conditioner" is used in which one outdoor unit having a large capacity is used in place of the plurality of outdoor units 3na and a plurality of indoor units 3nb are connected to this outdoor unit.

In such an air conditioner called a "one-room multi-air conditioner", the air conditioning load greatly differs depending on the number of operating indoor units, so that it is inevitable to use an outdoor unit whose capacity can be controlled. However, when controlling the outdoor unit, there is a problem that it is difficult to appropriately determine the output and suppress the temperature unevenness to a sufficiently low level.

[Object of the Invention]

The present invention has been made to solve the above problems, and is an air conditioner that can appropriately determine the output of an outdoor unit to which a plurality of indoor units are connected and that can suppress temperature unevenness indoors sufficiently low. The purpose is to provide a device.

[Outline of Invention]

The present invention, while detecting the room temperature and setting the room temperature for each of a plurality of indoor units, while providing a solenoid valve in the refrigerant passage, the average temperature of the room is set, the deviation between the average room temperature and the set average temperature of the detected temperature When the temperature exceeds the predetermined value, the capacity of the compressor is controlled based on the temperature deviation, and when the temperature deviation is less than the predetermined value, the refrigerant passage of the indoor unit in which the difference between the detected temperature and the set temperature is less than the predetermined value is closed. As described above, the solenoid valve is controlled, and the capacity of the compressor is controlled based on the deviation between the detected temperature of another indoor unit and the set temperature.

Example of Invention

FIG. 2 is a system diagram showing an overall configuration of an embodiment of the present invention, in which the outdoor unit 1 includes three indoor units 2a and 2a.
b and 2c are connected. Of these, indoor unit 1
Is a compressor 4 whose rotation speed is variable by an inverter 5, a control unit 6 for controlling the inverter 5, an indoor unit 2
a, 2b, 2c solenoid valve 7a provided in each refrigerant passage,
7b and 7c and throttle adjusting devices 8a, 8b and 8c that are inserted in series with these solenoid valves and adjust the refrigerant flow rate.
It has and. In addition, the indoor units 2a, 2b, 2c
Are temperature sensors 3a, 3b, 3c for detecting room temperature, respectively.
, And these temperature sensors are connected to the control unit 6 via a signal line 21.

On the other hand, the control unit 6 is connected with a temperature sensor 9 for detecting the temperature of the outdoor heat exchanger, a current sensor 10 for detecting the current of the compressor driving motor, etc., but these sensors are not directly related to the present invention. Therefore, the description thereof will be omitted below.

Next, FIG. 1 is a block diagram showing the detailed structure of the control unit 6 together with the elements related thereto. In the figure, temperature sensors 3a, 3b, each of the 3c room temperature _{T a,} T b, of magnitude corresponding to _{T c} temperature signal _{e Ta,}
Signal conversion circuits 11a and 11 for converting into e _Tb and e _Tc
b and 11c are connected. These signal conversion circuits 1
1a, 11b, 11c are temperature signals e _Ta , e _Tb , e.
It is connected to the temperature difference calculation units 20A and 20B via a switching circuit 12 that switches and outputs _Tc . Among these, the temperature difference calculation unit 20A inputs the temperature signals e _Ta , e _Tb , and e _Tc to obtain an average temperature thereof, and an average temperature setting for setting the average temperature of the room in which the indoor unit is arranged. And a comparator circuit for comparing the set average temperature and the average temperature obtained by the signal averaging circuit 13 to output a temperature deviation signal and adding a switching signal to the switching circuit 12 when the temperature deviation becomes zero. It is composed of 15 and. On the other hand, the temperature difference calculation unit 20B sets the room temperature for each indoor unit, temperature setters 16a, 16b, and 16c, set temperature signals of these temperature setters, and the temperature signal e _Ta ,
e _Tb , e _Tc are compared for each indoor unit to output a temperature deviation signal, and when the temperature deviation exceeds, for example, 4 ° C., a comparison circuit 17 a, 1 for adding a switching signal to the switching circuit 12
7b and 17c. In addition, the comparison circuit 1
5, 17a, 17b, and 17c are connected to a frequency determining circuit 18 that determines a frequency for modulating and controlling the inverter 5 based on the temperature deviation, and further, a comparing circuit 17a,
A solenoid valve control circuit 19 for controlling the solenoid valves 7a, 7b, 7c based on the temperature deviation is connected to 17b, 17c, respectively.

The operation of this embodiment configured as described above will be described with reference to FIGS.
The description will be made according to the flowchart of FIG. 5 also with reference to the drawings.

First, the indoor units 2a, 2b, 2c are arranged side by side in an elongated room as shown in FIG. 3, and these are connected to the outdoor unit 1. By performing the cooling operation of this air conditioner, the temperature distribution in the room changes sequentially as shown by the curves T ₀ to T ₄ , and the set value of the average temperature setter 14 is T _S. Then, the room temperature at the beginning of the operation at time t ₀ is uniformly higher than the set average temperature T _{S as} shown by the curve T ₀ , and the switching circuit 1
2 indicates the temperature signals e _Ta , e _Tb , e in the temperature difference calculation unit 20A.
_It is in a state of giving _Tc .

In this state, the signal averaging circuit 13 causes the temperature signals e _Ta ,
An arithmetic operation for _obtaining the average value e _TM of e _Tb and e _Tc is performed (step 101), and then the average value e _TM is compared with the output of the temperature setter 14 by the comparison circuit 15, whereby the average temperature T in the room is calculated. The deviation between _M and the set average temperature T _S is calculated (step 102). Also added to the inverter 5 to determine the frequency at which the frequency determination circuit 18 corresponding to the temperature difference _(T M -T _S). In this case, the solenoid valves 7a, 7
b, 7c is not energized, and the indoor units 2a, 2b, 2
All the refrigerant passages of c are opened (step 103).

Thus, the normal pull-down control is performed until the average temperature T _{M in the} room reaches the set average temperature T _S, and the temperature distribution in the room changes like a curve T ₀ → T ₁ → T ₂ → T ₃ .

At this time, the temperature sensor 3a, 3b, changes as the indoor temperature _{T a, T b, T c} detected by 3c, Fig. 4 with the passage of the average temperature _{T M} is the time (a), the indoor unit 2a, 2b and 2c maintain the same output state as shown in FIGS. 4 (b) to 4 (d). The output of the outdoor unit corresponds to the sum of the outputs of the indoor units as shown in FIG. 4 (e), and the solenoid valves 7a, 7
Both b and 7c are open at this point as shown in FIGS. 4 (f) to (h).

Next, when the average temperature T _{M in the} room becomes equal to the set average temperature T _S at time t ₁ , the comparison circuit 15 gives a switching signal to the switching circuit 12 (step 104), so the temperature signal e
_Ta , e _Tb , and e _Tc are comparator circuits 17a and 17 respectively.
b, 17c, where the temperature setters 16a, 1c
It is compared with the outputs of 6b and 16c (step 105).
If it is determined by this comparison that the detected temperature in the indoor unit 2b is lower than the set temperature, the solenoid valve control circuit 19 energizes the solenoid valve 7b to close it as shown in FIG. 4 (g), and further, If it is determined that the temperature detected by the temperature sensor 3a is also lower than the temperature set by the temperature setter 16a, the solenoid valve 7a is also closed (step 106). At this time,
The detected temperature is higher than the set temperature. The temperature deviation signal of the comparison circuit is applied to the frequency determination circuit 18.

Next, the frequency determination circuit 18 calculates the number of units whose detected temperature is not lower than the set temperature (step 107), further determines the frequency corresponding to the number of units and the temperature deviation, and applies it to the inverter 5.

Thus, the indoor unit in the place with low room temperature does not perform the air conditioning operation, and the indoor unit in the place with high room temperature performs the air conditioning operation.

Even when the control mode is entered, the set temperature T _Si set for each indoor unit may be lower than the set average temperature T _{S of the} entire room. In such a case, it is judged whether or not the deviation between the set temperature and the detected temperature exceeds 4 ° C. (step 109), and if it does not exceed 4 ° C., the compressor drive motor is based on the maximum temperature deviation. The frequency of is determined (step 110).

Then, if there is a temperature deviation of more than 4 ° C. at time T ₂ , the corresponding comparison circuits 17a, 17b, 17c.
Then, a switching signal is applied to the switching circuit 12, and the control mode is again shifted to the air-conditioning operation in all the indoor units based on the output of the temperature deviation computing unit 20A (step 103).

Here, the mode in which the capacity of the compressor 4 is controlled based on the temperature deviation signal of the temperature deviation calculation unit 20A is a control mode [I],
If the mode for controlling the capacity of the compressor 4 based on the temperature deviation signal of the temperature deviation calculation unit 20B is the control mode [II], the control mode [I] is used from time T ₀ to time T ₁ as shown in FIG. Overall control is performed, and from time T ₁ to time T
Up to _2, individual control by the control mode [II] is performed, and after time T ₃ , the overall control by the control mode [I] is performed again.

Thus, according to this embodiment, the temperature of the entire room is quickly cooled by the control mode [I], and when the average temperature reaches the set average temperature, the indoor units are individually controlled by the control mode [II] to make the indoor temperature uniform. Therefore, the output of the outdoor unit is appropriately determined with respect to the light weight of the air conditioning load, and at the same time, the temperature unevenness in the room can be suppressed sufficiently low.

In the above embodiment, the case of the cooling operation has been described, but in the case of the heating operation, the comparison determination step 10 in FIG.
If the inequality signs of 2, 105 and 109 are reversed, the same operation as described above can be performed.

In the above embodiment, the control mode is switched and the opening degree of the solenoid valve is controlled depending on whether the detected temperature and the set temperature are equal or not. The control mode switching or the like may be performed on the basis of, and in essence, it may be determined whether the control value exceeds a predetermined value or less than a predetermined value.

In the above embodiment, the temperature setting devices 16a, 16b, 1
6c and the average temperature setting device 14 are included in the control unit 6 of the outdoor unit 1, but the indoor units 2a, 2 are used as the temperature setting devices 16a, 16b, 16c.
The ones provided in b and 2c may be used, and the average temperature setting device 14 may be further provided in the room.

Furthermore, it goes without saying that the same control as described above can be performed even if a microcomputer is used as the control unit 6 in the above embodiment.

〔The invention's effect〕

As is clear from the above description, according to the present invention, there is an effect that the output of the outdoor unit can be appropriately determined and the temperature unevenness in the room can be suppressed sufficiently low.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an embodiment of the present invention, FIG. 2 is a system diagram showing an overall configuration of the same embodiment, and FIG. 3 is a view for explaining an operation of the embodiment. FIG. 4 is a temperature distribution diagram, FIG. 4 is a time chart for explaining the same action, FIG. 5 is a flow chart for explaining the same action, and FIG. 6 is a configuration explanatory view of a conventional air conditioner. 1 ... outdoor unit, 2a, 2b, 2c ... indoor unit,
3a, 3b, 3c ... Temperature sensor, 4 ... Compressor, 5 ... Inverter, 6 ... Control unit, 7a, 7b, 7c ... Solenoid valve, 12 ... Switching circuit, 14 ... Average temperature setter, 16a,
16b, 16c ... Temperature setting device, 15, 17a, 17b,
17c ... Comparison circuit, 18 ... Frequency determination circuit, 19 ... Solenoid valve control circuit, 20A, 20B ... Temperature difference calculation section.

Claims (2)

[Claims] 1. An air conditioner in which a plurality of indoor units arranged in the same room are connected to an outdoor unit having a compressor whose capacity is controllable, and the room temperature is detected and set for each indoor unit. A temperature sensor and a temperature setter, an average temperature setter for setting the average temperature in the room, a solenoid valve provided in each refrigerant passage of the indoor unit, and an average temperature obtained by averaging the detected temperatures of the temperature sensor and the average. When the deviation from the set average temperature of the temperature setter exceeds a predetermined value, the solenoid valve is controlled so as to open all the refrigerant passages of the indoor units, and based on the deviation between the average temperature and the set average temperature. The capacity of the compressor by controlling the temperature, and when the deviation between the average temperature and the set average temperature is less than or equal to a predetermined value, the detected temperature of the temperature sensor and the set temperature of the temperature setter. The solenoid valve is controlled so as to close the refrigerant passage of the indoor unit whose deviation is equal to or less than a predetermined value, and the compressor is operated based on the deviation between the detected temperature and the set temperature of the indoor unit in which the refrigerant passage is opened. An air conditioner comprising a control unit for controlling. 2. The first temperature difference, wherein the control unit averages the temperatures detected by the temperature sensor, compares the average temperature with the average temperature set by the average temperature setter, and outputs a temperature deviation signal. A calculation unit, a second temperature difference calculation unit that compares the detected temperature of the temperature sensor with the set temperature of the temperature setting device and outputs a temperature deviation signal, and a temperature deviation signal of the second temperature difference calculation unit Is a predetermined value or less, a solenoid valve control circuit that controls the solenoid valve so as to close the refrigerant passage of the indoor unit, and the first when the temperature deviation signal of the first temperature difference calculation unit exceeds a predetermined value. If the temperature deviation signal is less than or equal to a predetermined value, the second temperature difference calculator is selected.
And a frequency determination circuit that determines the power supply frequency of the compressor drive motor based on the temperature deviation signal of the temperature difference calculation unit selected by the switching circuit. The air conditioner according to claim 1.