JP3333767B2 - Control method of inverter 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 a method for controlling an inverter air conditioner, and more particularly, to a method for comparing the surface temperatures of a condenser and an evaporator with the temperature of the air around them. When the difference reaches a preset temperature difference,
The present invention relates to a method for controlling an inverter cooling / heating device that can stably circulate a refrigerant by adjusting an operation frequency.

[0002]

2. Description of the Related Art In general, a cooling and heating device is roughly classified into an operating and stopping (ON-OFF) cooling and heating device and an inverter cooling and heating device according to a driving system of a compressor. The driving speed of the compressor was controlled by utilizing this.

[0003] In a conventional inverter air conditioner,
As shown in FIG. 2, the compressor 11 compresses the refrigerant gas.
A four-way valve 15 for changing the circulation direction of the refrigerant gas compressed by the compressor by cooling or heating the room temperature, and the four-way valve 15 is connected by a pipe, and the gas flowing through the pipe An indoor heat exchanger 13 for exchanging heat between the indoor heat exchanger and the indoor air; an expansion valve 14 connected to the indoor heat exchanger 13 by a pipe to adjust a pressure of gas flowing through the pipe; And an outdoor heat exchanger 12 for performing heat exchange between a gas flowing through the piping and outdoor air.

[0004] The operation of the conventional inverter air conditioner thus constructed will be described below with reference to the drawings. First, when the inverter cooling and heating device performs a heating operation,
The refrigerant gas output from the compressor 11 is condensed by receiving pressure in the indoor heat exchanger 13 provided between the four-way valve 15 and the expansion valve 14, so that the temperature rises. Because the temperature of the room also rises, heat exchange is performed with the room air to increase the room temperature. Then, after the temperature of the gas deprived of the indoor air by the indoor heat exchanger 13 decreases, the gas passes through the expansion valve 14, flows into the outdoor heat exchanger 12 through the pipe, and evaporates. , And flows into the compressor 11 again.

On the other hand, when the inverter cooling / heating device performs a cooling operation, the refrigerant gas output from the compressor 11 is supplied to the outdoor heat exchanger 12 provided between the four-way valve 15 and the expansion valve 14.
Since the temperature is increased by being condensed by receiving the pressure inside, the temperature of the outdoor heat exchanger 12 is also increased, so that heat is radiated to the outdoor air. Next, the gas whose temperature has been reduced by the outdoor heat exchanger 12 passes through the expansion valve 14 and is evaporated by the indoor heat exchanger 13 to remove heat from the indoor air to lower the indoor temperature. Again through the compressor 11
Flowed into.

Therefore, when the user operates the inverter air conditioner for cooling or heating, a microcomputer (not shown) of the air conditioner determines the circulation direction of the refrigerant gas. Further, the microcomputer detects the temperature set by the user and the indoor and outdoor temperatures to determine an operating frequency at which the compressor 11 is driven, and applies the determined operating frequency to an inverter circuit to apply the determined operating frequency to the compressor circuit. And the inverter cooling / heating device operates as desired by the user.

Here, the operating frequency of the compressor 11 is
It is an element that adjusts the magnitude of the pressure of the indoor heat exchanger and the outdoor heat exchanger.If the operating frequency is high, the pressure difference between the indoor exchanger and the outdoor exchanger becomes large. The pressure difference with the outdoor exchanger is reduced.

The indoor heat exchanger 13 and the outdoor heat exchanger 12 function as a condenser or an evaporator depending on the circulation direction of the refrigerant gas or the type of operation (cooling or heating). That is, when performing a heating operation, the indoor heat exchanger functions as a condenser, and the outdoor heat exchanger functions as an evaporator.When performing a cooling operation, the indoor heat exchanger functions as an evaporator. The outdoor heat exchanger functions as a condenser.

Here, in the inverter cooling / heating device, since the indoor and outdoor heat exchangers perform the opposite functions depending on the gas circulation direction, they are called a condenser and an evaporator as shown in FIG. The following is a description of heat exchange in the inverter cooling / heating device using terms. FIG. 3 is a Ph graph showing the circulation of the refrigerant gas used in the inverter cooling / heating device. In the figure,
A is a graph showing the relationship between the pressure (P) and the enthalpy (h), B1 to B4 are graphs showing the circulation of the refrigerant gas, and C is the temperature of air performing heat exchange with the condenser. The graph D is a graph showing the temperature of the air that exchanges heat with the evaporator.

As shown in the drawing, the temperature B1 of the condenser is set higher than the temperature C of the air at the place where the condenser is installed, and the temperature B3 of the evaporator is set at the temperature B3 of the air where the evaporator is installed. In order to circulate the refrigerant gas at a temperature lower than the temperature D, the condenser and the evaporator exchange heat with the air around them. That is, since the temperature B1 of the condenser is higher than the temperature C of the air, heat is transferred to the air, and the temperature B3 of the evaporator is lower than the temperature D of the air, so that heat is transferred from the air. Is done. Thus, in the conventional inverter cooling / heating device, the temperature of the condenser needs to be set higher than the temperature of the surrounding air, and the temperature of the evaporator needs to be set lower than the temperature of the surrounding air. .

[0011]

However, in such a conventional inverter cooling and heating apparatus, since the temperature range of the air around the place where the condenser and the evaporator are installed is arbitrarily set, the condensing is not possible. It was extremely difficult to operate the air conditioner by setting the temperature of the vessel higher than the temperature of the surrounding air and setting the temperature of the evaporator lower than the temperature of the surrounding air. That is, in the case of the heating operation, the outdoor temperature is-
When the temperature changes from 10 ° C to 15 ° C, the indoor temperature is 0 ° C to 30 ° C.
° C. In the case of cooling operation, the outdoor temperature is 15 ° C.
When the temperature changes from 15 ° C to 35 ° C, the indoor temperature is 15 ° C to 30 ° C.
It should have changed to ° C.

Therefore, if it is attempted to operate the inverter air conditioner so as to maintain the indoor temperature at the temperature set by the user while satisfying the ambient temperature condition, a control method is difficult, for example, when the outdoor temperature is 35 ° C. When the user sets the set temperature to 18 ° C. and operates the inverter air conditioner, the indoor temperature decreases more and more as the inverter air conditioner operates, for example, from 20 ° C. to 19 ° C.
Therefore, the operating frequency of the compressor is, for example, 5
Reduced to 0 Hz and 40 Hz. At this time, even if the operation frequency is continuously lowered, there is an inconvenience that the cooling circulation is instantaneously broken because the information on the temperature difference between the condenser and the evaporator is not input.

The present invention has been made in view of such a conventional problem, and compares the surface temperatures of a condenser and an evaporator with the temperatures of air around the condenser and the evaporator, and determines a temperature difference between them in advance. It is an object of the present invention to provide a method for controlling an inverter cooling / heating device that can stably circulate a refrigerant by adjusting an operation frequency when a temperature difference is reached.

[0014]

In order to achieve the above object, in the control method of the inverter cooling / heating apparatus according to the present invention, the surface temperature of each of the condenser and the evaporator and the temperature of the air around them are determined. , Respectively, a step of comparing each surface temperature detected from the condenser and the evaporator with a temperature of air detected from the periphery thereof, and a comparison result, The temperature of the air around the condenser is higher than the surface temperature of the evaporator by a predetermined first temperature, and the surface temperature of the condenser is higher than the temperature of the air around the condenser by a predetermined second temperature. Performing the operation at the preset operation frequency only when the operation frequency is high, and otherwise performing the operation at the operation frequency one step higher than the preset operation frequency. And it features.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. In the control method of the inverter cooling / heating device according to the present invention, as shown in FIG.
First, power is supplied to a general inverter cooling and heating apparatus as shown in FIG. 2 (ST1), and when a user sets the temperature, the microcomputer detects the temperature of the indoor and outdoor air, and based on the detected temperature, the compressor. Determine the operating frequency of

Next, when the compressor is driven at the determined operating frequency, the pressure of the condenser and the evaporator is generated, and the microcomputer keeps the pressure difference between the condenser and the compressor constant. Operation is performed (ST2).

At this time, the microcomputer determines whether the inverter cooling / heating device should perform a cooling operation or a heating operation (ST3),
If it is determined that the cooling operation has been set, the surface temperature of the indoor heat exchanger (evaporator) that performs heat exchange by sucking indoor air is detected and compared with the temperature of the sucked indoor air, respectively. It is determined whether the temperature difference is 2 ° C. or more (ST4).

Next, in the step (ST4), if the temperature difference between the temperature of the drawn indoor air and the surface temperature of the indoor heat exchanger (evaporator) is 2 ° C. or more, the outdoor air is further sucked. The surface temperature of the outdoor heat exchanger (condenser) that performs heat exchange with the temperature of the outdoor air taken in is detected and compared, and if the temperature difference is 2 ° C. or more, it is set in advance. Operate the compressor at the operating frequency (ST
5).

In the step (ST4), the difference between the temperature of the drawn indoor air and the surface temperature of the indoor heat exchanger is 2 ° C. or less, or the step (ST5)
When the temperature difference between the surface temperature of the outdoor heat exchanger and the temperature of the sucked outdoor air is 2 ° C. or less, the operation is performed at an operation frequency one step higher than a preset operation frequency (ST8). .

On the other hand, if it is determined in the step (ST3) that the inverter cooling / heating device is set to the heating operation, the surface temperature of the indoor heat exchanger (condenser) which takes in indoor air and exchanges heat is determined. The temperature of the inhaled room air is detected and compared with each other, and it is determined whether or not the temperature difference is 2 ° C. or more (ST6).

Next, in the step (ST6), when the temperature difference between the surface temperature of the indoor heat exchanger and the temperature of the sucked indoor air is 2 ° C. or more, the outdoor air is further sucked to perform heat exchange. The surface temperature of the outdoor heat exchanger (evaporator) to be performed and the temperature of the sucked outdoor air are detected and compared, and if the temperature difference is 2 ° C. or more, the compression is performed at a preset operation frequency. The machine is operated (ST7).

In the step (ST6), the difference between the temperature of the drawn indoor air and the surface temperature of the indoor heat exchanger is 2 ° C. or less, or the step (ST7)
When the temperature difference between the surface temperature of the outdoor heat exchanger and the temperature of the sucked outdoor air is 2 ° C. or less, the operation is performed at an operation frequency one step higher than a preset operation frequency (ST8). .

Therefore, in the control method of the inverter cooling and heating apparatus according to the present invention, the temperature difference between the surface temperature of the indoor heat exchanger and the temperature of the sucked indoor air is maintained at least ± 2 ° C. or more. The temperature difference between the surface temperature of the heat exchanger and the temperature of the sucked outdoor air is maintained at least ± 2 ° C. or more.

On the other hand, the temperature difference between the surface temperature of the indoor heat exchanger and the temperature of the drawn indoor air is 2 ° C. or more, or the surface temperature of the outdoor heat exchanger and the temperature of the drawn outdoor air are different from each other. When the temperature difference is 2 ° C. or more, the operating frequency of the compressor is increased one step at a time, and the pressure (temperature) of the indoor heat exchanger is reduced to operate, so that the cooling circulation is not broken.

The temperature difference between the surface temperature of the indoor heat exchanger and the temperature of the drawn indoor air is 2 ° C. or more, or the surface temperature of the outdoor heat exchanger and the temperature of the drawn outdoor air are different from each other. If the temperature difference is 2 ° C. or more, the operating frequency of the compressor is increased one step at a time to reduce the pressure (temperature) of the outdoor heat exchanger to operate, so that the heating circulation is not broken.

[0026]

As described above, in the control method of the inverter cooling / heating device according to the present invention, the surface temperature of the indoor / outdoor heat exchanger and the temperature of the sucked indoor / outdoor air during the cooling and heating operations. To determine the operating frequency of the compressor, and apply the determined operating frequency to the inverter circuit to control the operation of the compressor. There is an effect that the inverter cooling and heating device can be efficiently performed without breaking circulation with heating.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for controlling an inverter cooling / heating device according to the present invention.

FIG. 2 is a configuration diagram showing a general inverter cooling / heating device.

FIG. 3 is a Ph (pressure and enthalpy) graph showing circulation of a circulating gas in a conventional inverter cooling / heating device.

[Explanation of symbols]

 11 ... Compressor 12 ... Outdoor heat exchanger 13 ... Indoor heat exchanger 14 ... Expansion valve 15 ... Four-way valve

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Haun Yong J. Republic of Korea, Seoul, Yongdan-Park, Yoido-Don, Misun Apartment B-107 Examiner Eiji Shoji (56) References JP-A-7-35391 (JP) , A) JP-A-4-155139 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 11/02 102

Claims (3)

(57) [Claims] 1. A method for controlling an inverter air conditioner according to an operation frequency, comprising: detecting a surface temperature of each of a condenser and an evaporator and a temperature of air around the condenser and the evaporator; Comparing each surface temperature detected from the evaporator and the surface temperature detected from the evaporator with the temperature of the air detected from the periphery thereof. As a result, the temperature of the air around the evaporator becomes the surface of the evaporator. Only when the surface temperature of the condenser is higher by a preset second temperature than the temperature of the air around the condenser by a preset first temperature higher than the temperature by the preset operation frequency, Driving, otherwise,
Controlling the operation at an operation frequency one step higher than the preset operation frequency. 2. The method according to claim 1, further comprising a temperature setting step of setting a room temperature desired by a user. 3. The method according to claim 1, wherein the first and second preset temperatures are 2 ° C.