JPS6024376B2 - Air conditioner control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an air conditioner equipped with a variable capacity compressor, and aims to provide a control device for an air conditioner that can control not only the temperature but also the humidity of an air-conditioned space. purpose.

That is, it is an object of the present invention to provide a control device that achieves the above object using only a temperature detection means without having a humidity detection means.

A subordinate air conditioner, for example, a room air conditioner, has a control device having the configuration shown in FIG. 1 and which performs roughly the following control.

A variable capacity compressor 1, a first fan motor 3 as a means for controlling the air flow rate of the condenser 2 as a heat source side heat exchanger, a capillary tube 4, an evaporator 6 as a user side heat exchanger, and evaporator air flow rate control. In an air conditioner equipped with a second fan motor 5 as a means, the temperature of the space being cooled by the air conditioner is detected by some means and the capacity of the variable capacity compressor is controlled to maintain a substantially constant space temperature. obtain. In this type of control, the humidity in the space remains constant, and the compressor capacity is controlled to be low when the load is low, which causes the evaporation temperature to rise and the dehumidifying capacity to decrease. As a result, the temperature of the space becomes high, causing discomfort. Some devices control the fan motor 3 according to the outside temperature, but the purpose of this is not to control spatial humidity, but rather to suppress noise. Control of the second fan motor 5 can also be seen now, but this is also used to improve the temperature distribution in the space, rather than to control the humidity in the space. Therefore, in air conditioners, including this type of air conditioner, the humidity in the space is not controlled and is left to its own devices, resulting in air conditioning that is sometimes unpleasant in terms of humidity. In a cooling system using an air heat source, the temperature of the evaporator changes depending on the wet bulb temperature of the air-conditioned space, the outside air temperature, the air flow rate of the evaporator and condenser, and the capacity of the compressor, as shown in Figures 2 to 4. do.

The temperature of the evaporator greatly affects the humidity control of the air conditioned space, and conventional air conditioners suffer from the above-mentioned drawbacks.
The present invention also provides space temperature setting means for presetting the temperature of an air-conditioned space, space temperature detection means, and the variable capacity compressor according to the difference between the space temperature detection means and the space temperature setting means. In addition to a room temperature adjustment unit that controls the capacity control means, the heat source side heat exchanger ventilation amount control means, and the usage side heat exchanger ventilation amount control means to preset values,
a heat exchanger temperature detection means for detecting the temperature of the use-side heat exchanger; a heat exchanger temperature calculation section that sets an upper limit and a lower limit temperature of the use-side heat exchanger according to a signal from the space temperature setting means; When the signal from the heat exchanger temperature detection means exceeds the temperature set by the heat exchanger temperature calculation section, the signal from the room temperature adjustment section is given priority to the capacity control means of the variable capacity compressor and the heat source side. It is provided with a heat exchanger temperature control section that controls the heat exchanger ventilation amount control means and the user-side heat exchanger ventilation amount control means. With this configuration, when the set temperature of the cooling room is determined, the temperature of the evaporator as a user-side heat exchanger necessary to maintain the humidity of the room at an appropriate value is determined by the fifth
The upper and lower limit temperatures of this range are set by the heat exchanger temperature calculation unit to correspond to the shaded range shown in the figure, and when the signal from the heat exchanger temperature detection means deviates from this range, the heat exchanger temperature The air flow rate of the evaporator and condenser as shown in FIGS. 3 and 4 is given priority to the signal from the room temperature adjustment section by the adjustment section.
The capacity of the compressor is controlled to bring it back within this range.

A block diagram of this control device is shown in FIG. 6, and a flowchart of the heat exchanger temperature control section is shown in FIG. 7. 7th
The symbols used in the figure are as follows. Ts is the temperature of the evaporator, Tsu is the temperature of the evaporator at the ON point of the downward control, TsD is the temperature of the evaporator at the ON point of the upward control, Vi is the airflow rate of the evaporator, Vo is the airflow rate of the condenser, and RC is the compression Capacity of vessel, Vim
ax is the maximum value of Vi, Vimin is the minimum value of Vi, Vo
m omitted × is the maximum value of Vo, Vomin is the minimum value of Vo, R
The cm loss x is the maximum value of RC, and RCmjn is the minimum value of RC.
As shown in the figure, the control levels of the evaporator, condenser, and compressor are determined so that the COP does not become low.

Also, the mark is m is x. mln. This indicates a change in the direction of. As an example, if the temperature in the room is rising and the temperature Ts of the evaporator is set at the ON point T of the downward control, which is determined by the set value of the room temperature.
When su is exceeded, Ts-Tsu>○, and the descending control is activated. First, the air flow rate of the condenser is changed to the maximum value, and if Ts still does not decrease, the capacity of the compressor is changed to the maximum value. If the above is not satisfied, start reducing the amount of ventilation in the evaporator. Conversely, when the temperature of the evaporator exceeds the increase control ON point, the compressor capacity is decreased, the condenser airflow rate is decreased, and the evaporator airflow rate is increased in this order. Both ON
The points include considerations for adding a differential and preventing hunting, but are excluded for the sake of explanation. Although cooling has been explained, similar control is required for heating as well, since the relative humidity of the blown air is determined by the temperature of the heat exchanger on the user side.

A specific embodiment of the above-mentioned control device is shown in FIG. 10
It is a capacity control means for the variable capacity compressor 1. For example, if the compressor 1 is a pole number changing type, it is a pole number switching relay, and if it is a continuous rotation speed changing type, it is an inverter or a cyclotron. It is a converter.

Reference numeral 31 denotes a control device for the fan motor 3, which is, for example, a phase controller using a thyristor, a tap-switching IJ relay in the case of a tap-switching type motor, or a damper relationship control motor.

Reference numeral 51 denotes a control device for the fan motor 5, and its specific means include the means described in connection with the control diamond 31.

7 is an embodiment of the control device according to the present invention.

Space temperature detection means 7A. The outputs of the heat exchanger temperature detection means 7B and the space temperature setting means 7C are input to a control circuit 70 described below. The control circuit 7D is roughly configured as follows. The outputs of the temperature detection means 7A and 7B are A, which will be described later.
Appropriate signal processing is performed by processing circuits 7D1 and 7D2 so that the signal is passed to the input of the /D converter 7D4, and is input to the analog multiplexer 7D3. Although the output of the temperature setting means 7C is directly inputted to the analog multiplexer 7D3 in the figure, it may be inputted via an appropriate signal processing circuit depending on the case. The analog multiplexer 7D3 is controlled by the microcomputer 7D5 with a signal MC, and selectively inputs and outputs only one input from a large number of inputs. The output of analog multiplexer 7D3 is controlled by signal AC from microcomputer 7D5, and is converted into a digital signal by A/D converter 7D4. The output of A/D converter 7D4 is input to microcomputer 7D5. The microcomputer 705 can have a one-chip configuration or a multiple-chip configuration as necessary. Microcomputer 7D5
receives the signal from the space temperature setting means 7C and calculates and sets the upper and lower limit temperatures by the heat exchanger temperature calculation main stage (not shown), and the signal from the heat exchanger temperature detection means falls within the calculated temperature range. In some cases, a room temperature control section (not shown) may be used, and if the above range is exceeded, a heat exchanger temperature control section (not shown) may be used.
(not shown) outputs control signals for the compressor and fan motors 3 and 5. This signal is transferred to the D/A converter 7D6, 7
The signals are converted into analog quantities in D7 and 7D8, and inputted to control means 10, 31, and 51 as outputs of the control device 7, respectively.
Here, typical examples of temperature detection means include thermocouples, thermistors, semiconductor temperature sensors, and the like.

Further, the temperature setting means 7C includes a variable resistor, a multi-contact switch, etc. as shown in the figure. When using a multi-contact switch, it is also possible to input directly to the microcomputer 7D5. Furthermore, if the control means 10, 31, 51 is capable of digital input, the D/A converter 7D
6 to 7D8 are no longer necessary. According to the present invention, it is possible to realize an air conditioner that can control the humidity in an air-conditioned space using only a temperature detection means without having a humidity detection element, and can provide a space that is extremely comfortable compared to conventional ones. The effect is extremely large.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of an air conditioner as an example of an air conditioner, Fig. 2 is a characteristic diagram showing the relationship between the outside temperature of the space, the wet bulb temperature of the air-conditioned space, and the evaporator temperature, and Fig. 3 is the evaporator, A characteristic diagram showing the relationship between condenser ventilation volume and evaporator temperature, Figure 4 is a characteristic diagram showing the relationship between compressor capacity and evaporator temperature, and Figure 5 shows the appropriate evaporator temperature for the set temperature. Characteristic diagram, 6th
The figure is a block diagram of a control device for an air conditioner according to an embodiment of the present invention, FIG. 7 is a flowchart of the block diagram of FIG. 6, and FIG. 8 is a schematic explanatory diagram of the control device of the present invention. 1... Variable capacity compressor, 2... Heat source side heat exchanger, 3... First fan motor (heat source side heat exchanger ventilation amount control means), 5 ...Second fan motor (use side heat exchanger ventilation amount control means), 6...Use side heat exchanger, 7A...Space temperature detection means, 7B.
... Heat exchanger temperature detection means, 7C ... Space temperature setting means, 7D ... Control circuit, 7D5 ...
... A microcomputer consisting of a room temperature control section, a heat exchanger temperature calculation section, and a heat exchanger temperature control section, 7...
Control device, 10... Compressor capacity control means. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure ○ Ship Figure 7 Figure 8

Claims (1)

[Claims] 1. Capacity control means for a variable capacity compressor, heat source side heat exchanger ventilation amount control means, user side heat exchanger ventilation amount control means,
space temperature setting means for presetting the temperature of the air-conditioned space; space temperature detection means; and capacity control means for the variable capacity compressor according to the difference between the space temperature detection means and the space temperature setting means. and a room temperature control unit that controls the heat source side heat exchanger ventilation amount control means and the usage side heat exchanger ventilation amount control means to preset values, and a heat exchanger that detects the temperature of the usage side heat exchanger. a temperature detecting means; a heat exchanger temperature calculation unit that sets upper and lower limit temperatures of the user-side heat exchanger according to a signal from the space temperature setting means; When the temperature exceeds the temperature set by the exchanger temperature calculation section, the capacity control means of the variable capacity compressor, the heat source side heat exchanger air flow rate control means, and the user side heat exchanger are given priority over the signal from the room temperature adjustment section. 1. A control device for an air conditioner, comprising: an airflow rate control means; and a heat exchanger temperature control section that controls the ventilation amount.