JPS61191822A - Control unit of air conditioner - Google Patents

Abstract

PURPOSE:To prevent overcooling of a space to be air-conditioned while preventing the moisture which has once been dehumidified from returning to the space to be air-conditioned by forcibly starting the operation of a compressor when the stopping time of the compressor reaches a predetermined time during the space cooling operation and switching an indoor blower to weak air flow. CONSTITUTION:A compressor 3 stops its operation after a time T1 the room temperature has reached a predetermined value, and the stopping time is counted by a timer 12. When the room temperature is more than a temperature (i.e. a set temperature) at which the compressor 3 is turned OFF at a point in time T2 after a predetermined time TM, the compressor 3 is forcibly started to operate to start the operation to prevent the moisture which has once been dehumidified from returning to the space to be air-conditioned. The operating time of the compressor 3 is counted by a timer 12, and the operation of the compressor 3 is continued for a predetermined time TN, that is, until a time lubricating oil which has been delivered to a freezing circuit together with a coolant by the operation of the compressor 3 returns to the compressor 3. During this time, the air flow quantity of an indoor blower 7 is switched to a weak air flow thereby to prevent extreme overcooling of the temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for an air conditioner that controls the temperature and humidity of an air-conditioned space.

2. Description of the Related Art In general, air conditioners operate the compressor according to the temperature set by a temperature sensor that detects the room temperature, as shown in Figure 4.
N, 0FFL temperature control is being performed.

In this case, it is well known that there is a predetermined differential D (temperature difference) between the temperature when the compressor is turned on (T2) and the temperature when it is turned off (T, ) according to the set temperature to prevent frequent turning on and off. This is a fact.

However, due to the presence of the differential D, depending on the load situation, the compressor may not restart from stopping (OFF).
When the operation is interrupted for a long time until the cooling operation is turned on, the moisture that has been dehumidified in the evaporator is circulated again into the air-conditioned space during this interruption, increasing the humidity and causing discomfort. It was something.

As a technology to prevent such defects, during cooling operation,
When the compressor stop time reaches a certain period of time TMK, the compressor is forced to start by changing the differential from D to d (d<<D), thereby preventing the compressor from running for a long time. There are known devices that prevent moisture that has been dehumidified from returning to the air-conditioned space due to the stopped state.

Problems to be Solved by the Invention By the way, when the compressor starts operating, lubricating oil is sent to the refrigeration circuit along with the refrigerant, and unless operation continues for a certain period of time, the lubricating oil sent out will not return to the compressor. . Therefore, from the viewpoint of protecting the compressor, a function is generally provided to continue the TN operation for a predetermined period of time once the compressor starts operating, as shown in FIG. Therefore, in the above control method,
When the compressor stop time reaches a certain time TM, the compressor is forcibly started, and the indoor blower air volume remains the set air volume and the TN compressor continues to operate for a predetermined period of time. The problem was that the temperature in the space could get too cold and the indoor coil could freeze.

In view of the above problems, the present invention aims to prevent moisture from returning to the air-conditioned space due to the stoppage of the compressor, without causing the temperature of the air-conditioned space to become too cold or freezing the indoor coil. be.

Means for Solving the Problems In order to solve the above-mentioned problems, the air conditioner control device of the present invention provides a control device for an air conditioner according to the present invention, in which the compressor is stopped for a certain period of time TM during cooling operation, and the room temperature is lower than that of the compressor. If the temperature is higher than the temperature required to turn off, the compressor is forced to start operating, and the indoor fan, which can be switched between strong and weak air volume, is switched to weak air for a predetermined period of time T.
The configuration is such that N operation continues.

Effect: With the above-described configuration, the present invention forcibly starts operating the compressor when the compressor stop time reaches a certain fixed time TM during cooling operation, thereby preventing the moisture that has been dehumidified from returning to the air-conditioned space. In addition to preventing the temperature of the air-conditioned space from becoming too cold, by switching the air volume of the indoor blower to a weak wind while TN operation continues for a predetermined period of time until the lubricating oil sent out from the compressor returns. It also has the effect of preventing indoor coils from freezing.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 3 shows a refrigeration system diagram of an air conditioner in one embodiment of the present invention. 1 is an indoor unit, and 2 is an outdoor unit. 3 is a compressor, 4 is an outdoor coil, 5 is a pressure reducer, and 6 is an indoor coil, which are connected in a ring to form a refrigeration circuit. Reference numeral 7 denotes an indoor blower that circulates air in the air-conditioned space and exchanges heat with the indoor coil 6. 8 is an outdoor blower for exchanging heat between the outside air and the outdoor coil 4.

FIG. 1 is comprised of a ROM 11 that stores a flat-head program for controlling circuit profile equipment in one embodiment of the present invention, and a timer 12. 13 is a temperature sensor that detects the temperature of the air-conditioned space and inputs the temperature data to the input terminal I0 of the controller 9; 14 is a driver and a relay; 7, the output terminal o0 of the controller 9
is connected to the compressor via the load driving means 14, and also to the output terminal 0.
1 and 0□ are respectively connected to the strong wind and weak wind taps of the indoor blower 70 via the load driving means 14.0 The operation of the air conditioner control device configured as below will be explained with reference to FIG. do.

At the start of operation, if the room temperature detected by the temperature pump 13 is higher than the set temperature, the compressor 3 continues to operate until the room temperature becomes below the set temperature, cooling the room temperature to the set temperature. At the same time, remove moisture. After T1, the compressor 3 is stopped, the stop time is counted by the timer 13, and at T2 after a certain period of time TM, the room temperature turns off the compressor 3.
If the temperature is higher than the set temperature (i.e. the set temperature), the compressor 3 is turned on.
The operation of the compressor 3 is forcibly started even if the temperature has not reached the set temperature by a differential D higher than the set temperature, and moisture once dehumidified is prevented from returning to the air-conditioned space. Then, the operating time of the compressor 3 is counted by the timer 13, and the time TN, that is, the time until the lubricating oil sent to the refrigeration circuit together with the refrigerant due to the operation of the compressor 3 returns to the compressor 3, is compressed. While the air blower 3 continues to operate, the air volume of the indoor blower 7 is switched to a weak wind to prevent the temperature from becoming too cold. When the room temperature has not reached the set temperature at time T3 after a certain period of time TN has elapsed, the operation of the compressor 3 starts at the time T3 when the room temperature reaches the set temperature.
4, but the air volume of the indoor blower 7 is switched from weak wind to strong wind at the original set air volume after time T3. By doing so, the indoor coil 6 is prevented from freezing, which occurs when operating for a long time in a weak wind.

Effects of the Invention As described above, the present invention counts the stop time of the compressor during cooling operation, and after a certain period of time has elapsed, when the room temperature is higher than the set temperature (i.e., higher than the temperature at which the compressor is turned off), the compressor is forcibly turned off. A controller should be installed to switch the indoor blower to low airflow and continue operation for a predetermined period of time when the compressor starts operating, and also to prevent moisture that has been dehumidified from returning to the air-conditioned space due to the compressor being stopped for a long time. By keeping the compressor running for a period of time until the compressor starts operating and the lubricating oil returns, and switching the indoor blower's air flow to low air only during that time, the air-conditioned space can become too cold. It can also prevent indoor coils from freezing, which can occur due to long-term operation in weak winds.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a control device for an air conditioner according to an embodiment of the present invention, Fig. fa2 is a time chart showing the operation of the device, Fig. 3 is a refrigeration circuit diagram of the air conditioner, and Fig. 4 , FIG. 6 is a time chart showing the operation of a conventional air conditioner control device. 3...Compressor, 4...Outdoor coil, 6
... pressure reducer, 6 ... indoor coil, 7.
...Indoor blower, 9...Controller, 13.
...Temperature sensor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure q, -1 Spider control device Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] A refrigeration circuit consisting of a compressor, an indoor coil, an outdoor coil, a pressure reducer, etc., an indoor blower capable of switching between strong and weak airflow to the indoor coil, and a temperature sensor that detects indoor temperature;
The compressor is controlled ON and OFF according to the detected room temperature, and the stop time of the compressor is counted, and after a certain period of time, when the room temperature is equal to or higher than a set temperature, the compressor is forcibly started to operate. A control device for an air conditioner, which includes a controller that switches an indoor blower to low airflow and continues operation for a predetermined period of time.