JPH08121848A - Air conditioner - Google Patents

Abstract

PURPOSE: To obtain an air conditioner which can keep a condensing pressure proper even when the ambient temperature is extremely low and a compressor is operated with a small number of revolutions. CONSTITUTION: A correcting means 9 whereby a control set value of a blower control means 7 for increasing and decreasing the number of operational revolutions of a blower 5 for condensation in accordance with a detected condensing temperature of a condenser 2 is reset to be high by a prescribed value when the number of revolutions of a compressor 1 is smaller than a prescribed value and when a detected temperature of an ambient temperature detecting means 8 is a prescribed value or below, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner.

[0002]

2. Description of the Related Art In recent years, air conditioners have been required to perform cooling operation even at low outside temperatures such as winter. However, a certain condensing pressure or compression ratio must be maintained in the operation of the compressor used. Therefore, as disclosed in Japanese Unexamined Patent Publication No. 2-275256, a temperature sensor is attached to the condenser, the condensing pressure is detected by controlling the condensing blower, and the condensing pressure suitable for the ambient temperature is secured. Things have been devised.

An example of a conventional air conditioner will be described below. FIG. 3 is a schematic configuration diagram of a conventional air conditioner.
In FIG. 3, 1 is a compressor, 2 is a condenser, 3 is a throttle means, and 4 is an evaporator, and these are connected in an annular shape to form a refrigeration circuit.

A condenser blower 5 is provided in the vicinity of the condenser 2 and is operated at a plurality of rotation speeds. A condenser 6 is attached to the condenser 2 to detect a condensation temperature. A temperature sensor 6 detects a temperature. Is a blower control means for increasing / decreasing the operating speed of the condensing blower 5.

The operation of the air conditioner configured as above will be described. In FIG. 3, during cooling operation,
The high-temperature high-pressure gas refrigerant discharged from the compressor 1 goes to the condenser 2 and is cooled and condensed by the air sent by the condensing blower 5. Further, it passes through the throttle means 3 to expand, become a low-temperature low-pressure refrigerant, and evaporate by the evaporator 4.

The blower control means 7 includes a condensation temperature sensor 6
The condensing pressure is controlled by increasing the rotation speed of the condensing blower 5 when the detected temperature is high and slowing it when the detected temperature is low.

The compressor 1 is controlled in rotation speed by a control means (not shown), for example, according to the room temperature.

[0008]

However, in the above-mentioned conventional configuration, when the ambient temperature of the condenser 2 is extremely low, for example, during cooling operation in the midwinter, it is sufficient to slow down the speed of the blower 5 for condensation. Due to the cold air being sent to it, the condensation pressure tends to be lower for the same evaporation pressure than when the ambient temperature is high. Further, when the compressor 1 whose rotational speed is controlled is used, the refrigerant circulation amount decreases when the operating rotational speed is low, so that the same throttling means 3 causes insufficient throttling and the compression ratio becomes smaller and smaller. I will end up. Therefore, the differential pressure for supplying oil to sliding parts such as bearings in the compressor 1 is insufficient, resulting in insufficient lubrication.
There was a drawback that the compressor 1 was broken.

The present invention solves the above-mentioned problems of the prior art. Even when the ambient temperature of the condenser is extremely low and the compressor whose rotational speed is controlled is operated at a low rotational speed, the condensing pressure can be controlled appropriately. It is an object to provide an air conditioner that can be maintained at a pressure.

[0010]

In order to achieve the above object, an air conditioner of the present invention includes a compressor operated at a plurality of rotation speeds, a condenser, a throttle means, and an evaporator as a refrigerant flow. With annular connection through a passage, provided in the vicinity of the condenser, ambient temperature detection means for detecting the ambient temperature, and provided in the vicinity of the condenser, a blower for condensation operated at a plurality of rotation speeds, Blower control means for detecting the condensing temperature of the condenser and increasing or decreasing the operating speed of the condensing blower according to the detected temperature, and the ambient temperature detecting means when the speed of the compressor is lower than a predetermined value. And a correction means for replacing the control set value of the blower control means by a predetermined value when the detected temperature becomes lower than a predetermined value.

[0011]

In the air conditioner of the present invention, the compressor operated at a plurality of rotation speeds, the condenser, the throttle means, and the evaporator are annularly connected via the refrigerant passage, and the condenser is also provided. Ambient temperature detecting means provided in the vicinity, for detecting the ambient temperature, provided in the vicinity of the condenser, a condensing blower operated at a plurality of rotation speeds, and detecting the condensing temperature of the condenser,
Blower control means for increasing or decreasing the operating speed of the condensing blower according to the detected temperature, and when the detected temperature of the ambient temperature detection means becomes a predetermined value or less when the rotational speed of the compressor is lower than a predetermined value When the compressor ambient temperature is extremely low and the compressor whose rotation speed is controlled is operated at a low rotation speed, the correction means replaces the control set value of the blower control means by a predetermined value. Also, the condensing pressure can be maintained at an appropriate pressure.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an air conditioner according to the present invention will be described below with reference to the drawings. It should be noted that the same configurations as those of the conventional one are denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a block diagram of an air conditioner according to an embodiment of the present invention, and FIG. 2 is a flow chart showing the operation of the embodiment.

In FIG. 1, reference numeral 8 denotes an ambient temperature detecting means provided near the condenser 2 for detecting an ambient temperature, and 9 denotes a temperature detected by the ambient temperature detecting means 8 when the rotation speed of the compressor 1 is lower than a predetermined value. Is a correction means for replacing the control set value of the blower control means 7 by a predetermined value when the value becomes less than a predetermined value.

The operation of the air conditioner configured as above will be described below. During the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 goes to the condenser 2,
The air blown by the condensing blower 5 cools and condenses, but the blower control means 7 increases the rotational speed of the condensing blower 5 when the temperature detected by the condensing temperature sensor 6 is high, and slows it when the temperature is low. , Controlling the condensing pressure.

When the ambient temperature of the condenser 2 is extremely low, such as during cooling operation in the middle of winter, and when the operating speed of the compressor 1 is low, the correction means 9 causes the control temperature in the blower control means 7 to be a predetermined value. Since the temperature is increased, the condensing pressure is controlled to be higher than that when the ambient temperature is high, and the compression ratio required for lubricating the compressor 1 can be secured.

Next, the above operation will be described with reference to the flowchart of FIG. In step 20, the ambient temperature Ta is detected.

At step 21, it is checked whether the detected ambient temperature is lower than a predetermined value (for example, 10 ° C.). If the detected ambient temperature is lower than the predetermined value, the process proceeds to step 22, and if not, the process proceeds to step 24.

In step 22, it is determined whether the operating speed of the compressor 1 is lower or higher than a predetermined value. If the operating speed is low, the process proceeds to step 23.

In step 23, the blower control means 7
The control set value of is increased by a predetermined value.

In step 24, the blower control means 7
Return the control setting value of to the initial value. As described above, the air conditioner of this embodiment includes the compressor 1 operated at a plurality of rotation speeds,
The condenser 2, the throttle means 3, and the evaporator 4 are annularly connected via a refrigerant flow path, and are provided in the vicinity of the condenser 2 and an ambient temperature detecting means 8 for detecting the ambient temperature, and the condenser 2 are provided. Blower control means 7 that is provided in the vicinity and that detects the condensation temperature of the condenser blower 5 that is operated at a plurality of rotation speeds and the condensation temperature of the condenser 2 and that increases or decreases the operating rotation speed of the condensation blower 5 according to the detected temperature. And a correction means 9 for replacing the control set value of the blower control means 7 by a predetermined value when the temperature detected by the ambient temperature detection means 8 becomes a predetermined value or less when the rotation speed of the compressor 1 is lower than the predetermined value. Therefore, the condenser pressure can be maintained at an appropriate pressure even when the ambient temperature of the condenser is extremely low and the compressor 1 whose rotation speed is controlled is operated at a low rotation speed.

[0022]

As described above, according to the present invention, the compressor, the condenser, the throttle means, and the evaporator, which are operated at a plurality of rotation speeds, are annularly connected through the refrigerant flow path, Ambient temperature detecting means provided in the vicinity of the condenser, for detecting the ambient temperature, a condenser blower provided in the vicinity of the condenser and operated at a plurality of rotation speeds, and detecting the condensation temperature of the condenser, Blower control means for increasing or decreasing the operating speed of the condensing blower according to the detected temperature, and when the detected temperature of the ambient temperature detection means becomes a predetermined value or less when the rotational speed of the compressor is lower than a predetermined value When the compressor ambient temperature is extremely low and the compressor whose rotation speed is controlled is operated at a low rotation speed, the correction means replaces the control set value of the blower control means by a predetermined value. Even the proper condensing pressure It is possible to maintain in force.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is a configuration diagram of a conventional air conditioner

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Throttling Means 4 Evaporator 5 Condensing Blower 7 Blower Control Means 8 Ambient Temperature Detecting Means 9 Correcting Means

Claims (1)

[Claims] 1. A compressor, which is operated at a plurality of rotation speeds, a condenser, a throttle means, and an evaporator, are connected in an annular shape through a refrigerant flow path, and are provided in the vicinity of the condenser, and an atmosphere is provided. Ambient temperature detecting means for detecting a temperature, a condenser blower provided in the vicinity of the condenser and operated at a plurality of rotation speeds, and a condenser temperature of the condenser are detected, and the condenser temperature is determined according to the detected temperature. A blower control means for increasing or decreasing the operating speed of the blower, and a control set value of the blower control means when the detected temperature of the ambient temperature detection means becomes a predetermined value or less when the rotation speed of the compressor is lower than a predetermined value. An air conditioner equipped with correction means for replacing the value by a higher value.