KR100888122B1 - Air conditioning device - Google Patents

Abstract

The present invention provides an air conditioner that is advantageous for stabilizing a system.

Solution The air conditioner has an indoor unit 1, an outdoor unit 2, and a refrigerant piping system 3. Each outdoor unit 2A, 2B has a compressor 22 having a suction port 22i and a discharge port 22p, a drive source 20 for driving the compressor 22, and an outdoor heat exchanger connected to the compressor 22. 23 and a control valve 25 for controlling the flow rate of the refrigerant flowing into the outdoor heat exchanger 23 that becomes the evaporator during the heating operation. The controller controls suction outdoor superheat degree calculating means for obtaining suction superheat degree of suction temperature of each compressor 22 and an outdoor unit having a relatively high suction superheat degree when the suction superheat degree of the suction temperature of the compressor 22 is different. The opening degree increase / decrease means which increases the opening degree of the valve 25 and reduces the opening degree of the control valve 25 of the outdoor unit where suction superheat degree is comparatively low is provided.

Description

Air Conditioning Equipment {AIR CONDITIONING DEVICE}

1 is a configuration diagram showing a relationship between an outdoor unit and an indoor unit of an air conditioner according to an embodiment.

2 is a circuit diagram showing a relationship between an outdoor unit and an indoor unit of an air conditioner.

3 is a circuit diagram showing the vicinity of a temperature sensor and a pressure sensor of the outdoor unit of the air conditioner.

4 is a flowchart of the control executed by the control unit of the air conditioner.

5 is a Molle diagram.

6 is a block diagram schematically showing a control unit.

7 is a configuration diagram showing a relationship between an outdoor unit and an indoor unit of an air conditioner according to another embodiment.

<Description of the code>

1A, 1B is an indoor unit, 2A, 2B is an outdoor unit, 3 is a refrigerant piping system, 4A, 4B is a control unit, 20 is an engine (drive source), 22 is a pressure (compression unit), 23 is an outdoor heat exchanger, 24 A, 24B represents a sensor (detection means), and 25 represents an electromagnetic regulation valve (control valve).

<Technology field>

The present invention relates to an air conditioner having a plurality of outdoor units.

<Background technology>

Background Art Conventionally, an air conditioner includes an indoor unit, an outdoor unit for adjusting a refrigerant to be air-conditioned in the indoor unit, a refrigerant piping system connecting each outdoor unit and each indoor unit, and a control unit for controlling the operation of the outdoor unit. The outdoor unit includes a compressor for compressing a refrigerant, a gas engine for driving the compressor, and an outdoor heat exchanger. According to this, a compressor is driven by the drive of a gas engine, and a refrigerant | coolant is compressed. In the indoor heat exchanger and the outdoor heat exchanger provided in the refrigerant circuit, condensation of the refrigerant and evaporation of the refrigerant are performed to perform air conditioning.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-347306

Problems to be Solved by the Invention

By the way, in recent years, the air conditioner provided with two or more outdoor units has been developed. According to this, the increase in the air conditioning load of the indoor unit can be coped. In addition, since a plurality of outdoor units are driven at the request of the air conditioning load of the indoor unit, an efficient driving area can be used, and the efficiency of the entire system of the air conditioner can be improved. In the above air conditioner, since a plurality of outdoor units are connected in a common refrigerant piping system, the fan functions when various factors (for example, avoidance control of lowering the engine speed of several outdoor units is controlled). Deterioration of the refrigerant occurs in the plurality of outdoor units. In this case, there is a limit in stabilizing the system of the air conditioner.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an air conditioner that is advantageous for stabilization of a system.

Means for solving the problem

The air conditioner according to the first aspect includes a plurality of single or single indoor units for air conditioning, a plurality of outdoor units for supplying refrigerant to the indoor units, a refrigerant piping system for connecting each outdoor unit and each indoor unit, and a control unit for controlling the operation of the outdoor unit. Equipped with

Each outdoor unit includes a compressor having a suction port for sucking refrigerant and a discharge port for discharging the compressed refrigerant, a drive source for driving the compressor, an outdoor heat exchanger connected to the compressor, and an outdoor heat exchanger that is an evaporator during the heating operation of the indoor unit. The opening degree which controls the flow volume of the refrigerant which flows into the air is variable, and it is provided with the control valve which functions as an expansion valve at the time of heating operation,

The control unit,

Suction superheat degree calculation means for obtaining a suction superheat degree of the suction temperature of the refrigerant sucked into the suction port of the compressor of each outdoor unit;

When the suction superheat degree of the suction temperature of the compressor of a plurality of outdoor units is different, the opening degree of a control valve is increased for the outdoor unit with a relatively high suction superheat degree, and the opening degree of a control valve is reduced for an outdoor unit with a relatively low suction superheat degree. The dog is also characterized by having a sensitization means.

According to the present invention, the suction superheat calculation unit calculates the suction superheat degree of the suction temperature of the compressor of each outdoor unit. Since the opening degree increasing / decreasing means estimates that the refrigerant flow rate is relatively insufficient in comparison with the other outdoor units, when the suction superheat degree of the suction temperature of the compressor of the plurality of outdoor units is different, the outdoor unit having a relatively high suction superheat degree is estimated. By increasing the opening degree, the flow rate of the refrigerant flowing into the outdoor heat exchanger, which becomes the evaporator during the heating operation of the indoor unit, is increased.

On the other hand, since the opening degree increasing / decreasing means estimates that the refrigerant flow rate is relatively excessive with respect to an outdoor unit having a relatively low suction superheat, compared with other outdoor units, the opening degree of the control valve is reduced, and the evaporator is operated during the heating operation of the indoor unit. Reduce the flow rate of refrigerant flowing into the outdoor heat exchanger. This optimizes the opening degree of the control valves in the plurality of outdoor units during the heating operation of the indoor unit. As a result, the excess and shortage of the refrigerant flow rates in the plurality of outdoor units is reduced, and the refrigerant flow rates in the plurality of outdoor units are further appropriated.

According to a preferred embodiment of the present invention, the outdoor units are the first outdoor unit and the second outdoor unit, and the control unit uses the command opening degree θ1 of the control valve of the first outdoor unit and the command opening degree θ2 of the control valve of the second outdoor unit based on the following equation. Decide by

(i) Command opening degree θ1 of the control valve of the first outdoor unit =

α1 × opening degree of the current control valve of the first outdoor unit × {suction superheat of the first outdoor unit / (suction superheat of the first outdoor unit + suction superheat of the second outdoor unit)} × 2

(ii) Command opening degree θ2 of the control valve of the second outdoor unit =

α2 × Opening degree of the current control valve of the second outdoor unit × {Suction superheat degree of the second outdoor unit / (Suction superheat degree of the first outdoor unit + Suction superheat degree of the second outdoor unit)} × 2

Where α1 and α2 are adjustment values. When the first outdoor unit and the second outdoor unit have the same capability, α1 and α2 can each be 1.0.

According to this invention, Preferably, the temperature sensor which detects the suction temperature of the refrigerant | coolant suctioned in the suction port of a compressor, and the pressure sensor which detects the pressure of the refrigerant | coolant suctioned in the suction port of a compressor are provided.

Here, when the suction temperature of the refrigerant sucked into the suction port of the compressor is T1 (° C) and the low pressure saturation temperature is T2 (° C), the suction superheat degree (superheat) (° C) = T1 (° C)-T2 (° C).

Effect of the Invention

According to the air conditioner according to the present invention, in the heating operation of the indoor unit, the excess and shortage of the refrigerant in the plurality of outdoor units is reduced, and the opening degree of the control valve in the outdoor unit is optimized. The system is stabilized.

Preferred Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described. This is applied to an engine driven air conditioner. 1 schematically shows the overall configuration. 2 shows a system piping diagram. The air conditioner includes a plurality of indoor units 1A and 1B for air conditioning indoors, a plurality of outdoor units 2A and 2B for adjusting refrigerants for air conditioning indoors, and each outdoor unit 2A and 2B The refrigerant piping system 3 which connects each indoor unit 1A, 1B is provided. The refrigerant piping system 3 is common to each outdoor unit 2A, 2B and each indoor unit 1A, 1B. The control part 4 has the 1st control part 4A mounted in the outdoor unit 2A, and the 2nd control part 4B mounted in the outdoor unit 2B. The first control section 4A has a memory element 40A (see FIG. 6).

The outdoor units 2A and 2B basically have the same components and are set to exhibit the same capability. For the outdoor units 2A and 2B, the outdoor unit 2A is set as a parent device (original device), and the outdoor unit 2B is set as a porcelain device (device included). The 1st control part 4A mounted in the outdoor unit 2A which is a main body outputs a command through the communication line 100 to the 2nd control part 4B mounted in the outdoor unit 2B which is self. The 2nd control part 4B mounted in the outdoor unit 2B which is self feeds back the operation state of the outdoor unit 2B via the communication line 100 to the 1st control part 4A mounted in the outdoor unit 2A which is a main body.

As shown in FIG. 2, the indoor units 1A and 1B are arranged indoors, an indoor heat exchanger 10 for exchanging heat between a refrigerant and indoor air for air conditioning, and an expansion valve 11 for expanding the refrigerant. ) As the base element. The number of indoor units may be any number, but is represented as indoor units 1A and 1B.

The outdoor units 2A and 2B are arranged outdoors. The outdoor units 2A and 2B include an engine 20 (drive source) formed of a gas engine, an accumulator 21 for accommodating refrigerant in a state in which a gaseous refrigerant and a liquid refrigerant are separated from each other, and a gas engine. A plurality of compressors 22 (compression unit) driven by the 20 to inhale and compress the refrigerant in the gaseous state of the accumulator 21 accompanying the operation, and an outdoor heat exchanger 23 for performing heat exchange of the refrigerant for air conditioning. ) As the base element. Here, when it is necessary to clearly distinguish, the engine of outdoor unit 2A is referred to as engine 20A, and the engine of outdoor unit 2B may be referred to as engine 20B. The engine speed of the engine 20A is detected by the first sensor 24A (detection means). The engine speed of the engine 20B is detected by the second sensor 24B (detection means).

In the indoor units 1A and 1B, the compressor 22 is interlocked by the engine 20 via a power transmission member such as a timing belt. Therefore, the gas engine 20 functions as a drive source of the compressor 22. The compressor 22 has a suction port 22i for sucking the gaseous refrigerant from the accumulator 21 into the compression chamber, and a discharge port 22p for discharging the high-pressure gaseous refrigerant compressed in the compression chamber.

As will be described later, in the return direction (arrow K1 direction) in which the refrigerant returns from the indoor units 1A and 1B to the outdoor units 2A and 2B during the heating operation, the control valve (upstream) of the outdoor heat exchanger 23 is provided. The solenoid regulating valve 25 and the check valve 26 which function as an expansion valve) are arrange | positioned in parallel. The check valve 26 allows the refrigerant to flow from the outdoor heat exchanger 23 of the outdoor units 2A and 2B to the indoor units 1A and 1B, but the outdoor of the outdoor units 2A and 2B from the indoor units 1A and 1B. Block the flow of the refrigerant to the heat exchanger (23). The electromagnetic adjustment valve 25 can adjust the opening degree by electrical control. The solenoid control valve 25 is equipped with the drive part, such as a motor or a solenoid, and the valve part which changes an opening degree by the drive of a drive part, and can make a flow volume variable. Since the control part 4 controls the drive part of the electromagnetic regulation valve 25, it can control the opening degree of the electromagnetic regulation valve 25. FIG.

(At heating driving)

First, the case where the room is heated will be described. In the heating operation, both of the outdoor units 2A and 2B are driven, and both basically perform the same function. When the gas engine 20 is driven by the fuel gas, the compressor 22 is driven so that the refrigerant in the gas state of the accumulator 21 is supplied to the suction port 21i of the accumulator 21 and the suction port of the compressor 22 ( It is sucked from 22i via the flow path and compressed in the compression chamber of the compressor 22. The gaseous refrigerant compressed to high temperature and high pressure is discharged from the discharge port 22p of the compressor 22 to reach the oil passage 3a and the oil separator 27. As described above, the oil is separated from the refrigerant in the oil separator 27. The high-temperature, high-pressure refrigerant in the gaseous state in which the oil is separated passes through the third port 28t of the four-way valve 28 and passes through the flow path 3c, the ball valve 291, the flow paths 3d, and 3e. In the heat exchanger 10, the indoor heat exchanger 10 exchanges heat with indoor air to condense (liquefy) the air. Since the heat of condensation is released to the room, the room is heated. Therefore, in the heating operation of the indoor units 1A and 1B, the indoor heat exchanger 10 functions as a condenser.

And the refrigerant | coolant which liquefied through the indoor heat exchanger 10 turns into a liquid state or a gas-liquid two-phase state, reaches the expansion valve 11, and expands the expansion valve 11 of the indoor units 1A and 1B. At low pressure. In addition, the low pressure refrigerant passes through the flow paths 3f and 3g, the ball valve 292, and the flow path 3h to the arrow K1 direction (in the heating operation, the direction from the indoor units 1A and 1B to the outdoor units 2A and 2B). ) Flows to the solenoid control valve 25, flows through the solenoid control valve 25, and reaches the outdoor heat exchanger (23). The refrigerant evaporates in the outdoor heat exchanger (23) to exchange heat with outside air. Therefore, the outdoor heat exchanger 23 also functions as an evaporator during the heating operation of the indoor units 1A and 1B. Here, in the heating operation of the indoor units 1A and 1B, the solenoid regulating valve 25 functions as an expansion valve to expand the refrigerant. Here, the opening degree of the solenoid adjustment valve 25 is adjustable. Therefore, at the time of heating operation of the indoor units 1A and 1B, the refrigerant returning from the indoor units 1A and 1B to the outdoor heat exchanger 23 of the outdoor units 2A and 2B in accordance with the opening degree of the solenoid regulating valve 25. The flow rate of can be adjusted.

The refrigerant flows back to the return port 21r of the accumulator 21 via the flow path 3k, the first port 28f of the four-way valve 28, the second port 28s, and the flow path 3m. The returned refrigerant is accommodated in the accumulator 21 in a state separated into a liquid refrigerant and a gas refrigerant. Moreover, the 1st fan 51 which blows toward the outdoor heat exchanger 23, and the 2nd fan 52 which blows toward the indoor heat exchanger 10 are provided.

Conventionally, an orifice and a capillary tube are attached to a portion where the solenoid regulating valve 25 is provided, but the orifice and the capillary tube have a fixed flow path cross section and are fixed. Therefore, it is necessary to set the flow path cross-sectional area of the orifice or capillary tube for each model of the air conditioner, and the other flow path cross-section also has the trouble of attaching the orifice or capillary tube to each model. In this aspect, the above-mentioned inconvenience is reduced because the solenoid regulating valve 25 of the flow path cross-sectional area is installed as a control valve.

According to this embodiment, at the time of said heating operation, the control part 4A reads the air conditioning load requested | required by the indoor units 1A, 1B. From the total of the air-conditioning load requested | required, the sum total of the refrigerant flow volume required for air regulation at the present time is calculated | required. From the total amount of refrigerant flow rate, the opening degree of the solenoid control valve 25 which supplies the refrigerant | coolant required to the outdoor heat exchanger 23 which functions as an evaporator at the time of a heating operation is calculated | required. According to this opening degree, the outdoor unit 2A, 2B is tested to drive in the same driving condition.

However, deflection may occur in the refrigerant flow rate due to various factors in the outdoor units 2A and 2B and the indoor units 1A and 1B. As a factor, a fan malfunction, execution of control which prevents excessive rise of the water temperature of an engine, etc. are illustrated.

In order to correct the deflection of the refrigerant flow rate, the control unit 4A controls the solenoid regulating valve so that the suction superheat is constant in each of the outdoor units 2A and 2B with respect to the amount of the refrigerant flowing into the outdoor heat exchanger functioning as the evaporator during the heating operation. 25) the opening degree is controlled. Thereby, unbalance of the refrigerant flow volume in each outdoor unit 2A, 2B is eliminated, without changing the whole refrigerant flow volume.

Hereinafter, further explanation will be given regarding the cancellation of unbalance. The control part 4A calculates the suction superheat degree of the suction temperature of the compressor 22 of each outdoor unit 2A, 2B. Specifically, in both the outdoor units 2A and 2B, the temperature sensor 80 which detects the suction temperature of the refrigerant | coolant suctioned in the suction port 22i of the compressor 22 is provided in the compressor 22. As shown in FIG. In both the outdoor units 2A and 2B, a pressure sensor 83 for detecting the pressure of the refrigerant sucked into the suction port 22i of the compressor 22 is provided between the accumulator 21 and the compressor 22. It is.

When the suction temperature of the refrigerant sucked into the suction port 22i of the compressor 22 is T1 (° C) and the low pressure saturation temperature is T2 (° C), the suction superheat degree (° C) is T1 (° C)-T2. It is calculated | required by (degreeC). T1 (° C) is detected by the temperature sensor 80. T2 (° C) is obtained as follows based on the pressure sensor 83.

The method for obtaining T2 (° C) will be described. 5 shows a mollier diagram of the refrigerant. The horizontal axis represents the enthalpy of the refrigerant. The vertical axis represents the pressure (absolute pressure) of the refrigerant. Line A1 represents a saturated liquid line. Line A2 represents a saturated steam line. Line A3 represents the dryness of the refrigerant. The area on the left side of the line A1 represents the liquid phase region of the refrigerant. The region on the right side of the line A2 represents the gas phase region of the refrigerant. The region enclosed by lines A1 and A2 represents a gas-liquid two-phase region. The pressure determined by the pressure sensor 83 is converted into absolute pressure, and combined with the longitudinal axis (absolute pressure) of the Molie diagram of FIG. When the intersection point of the virtual horizon HA passing through the absolute pressure and the line A3 is found, this intersection corresponds to T2 (° C).

For example, when the absolute pressure is 5 atm, the intersection of the imaginary horizontal line HA passing through the 5 atm and the line A3 is obtained, and this intersection (= T2) is -15 deg. Thus, the degree of inhalation superheat = T1 (占 폚)-T2 (占 폚) = -5 占 폚-(-15 占 폚) = 10 占 폚. Thus, the suction superheat degree (degreeC) of refrigerant | coolant is calculated | required with respect to the suction port 22i of the compressor 22 with respect to both outdoor units 2A and 2B, respectively.

In this way, the control unit 4A calculates the suction superheat degree of the suction temperature of the compressor 22 for both of the plurality of outdoor units 2A, 2B.

According to this embodiment, when the transients of the suction temperature of the compressor 22 of several outdoor unit 2A, 2B differ, the control part 4A has a suction superheat degree among the some outdoor unit 2A, 2B. For a relatively high outdoor unit, the opening degree of the solenoid control valve 25 (expansion valve) is increased to control the flow rate of the refrigerant flowing into the outdoor heat exchanger 23 (functioning as an evaporator during heating operation). . In addition, among the plurality of outdoor units 2A and 2B, the opening degree of the solenoid regulating valve 25 (expansion valve) is reduced with respect to the outdoor unit having a relatively low suction superheat degree, and the outdoor heat exchanger 23 (at heating operation). Control to reduce the flow rate of the refrigerant flowing into the e) is performed. As a result, excess or shortage of refrigerant in the plurality of outdoor units 2A and 2B is reduced during the heating operation of the indoor units 1A and 1B, and the solenoid regulating valves in both the outdoor units 2A and 2B are reduced. The opening degree of (25) is optimized. As a result, the system can be stabilized.

4 shows an example of a flow chart of the suction superheat degree control process executed by the control unit 4A. The flow chart is not limited to this. First, in the suction superheat degree control process, the temperature sensor 80 and the pressure sensor 83 are read into the outdoor units 2A and 2B (step S2). Next, for the outdoor units 2A and 2B, the suction temperature of the refrigerant sucked into the suction port 22i of the compressor 22 is calculated as T1 (° C) (step S4). The low pressure saturation temperature T2 (° C) of the refrigerant is obtained (step S6). Suction superheat degree (degreeC) is calculated | required about outdoor unit 2A, 2B (step S8). It is calculated | required as suction superheat degree (degreeC) = T1 (degreeC)-T2 (degreeC). Step S8 functions as a suction superheat degree calculation means.

Next, the difference between the suction superheat degree of outdoor unit 2A and the suction superheat degree of outdoor unit 2B is calculated | required (step S10). It is determined whether the difference is larger than the predetermined value [epsilon] (step S12). If the difference is smaller than the predetermined value [epsilon], it returns to the main routine.

If the difference is larger than the predetermined value [epsilon], the command opening degree [theta] 1 of the solenoid regulating valve 25 of outdoor unit 2A is calculated | required based on following Formula (step S14). In addition, the command opening degree θ2 of the electromagnetic control valve 25 of the outdoor unit 2B is obtained based on two expressions (step S16). Next, the command opening degree θ1 is output to the electromagnetic control valve 25 of the outdoor unit 2A, and the command opening degree θ2 is output to the electronic control valve 25 of the outdoor unit 2B (step S18). It waits for a predetermined time until the opening degree of the electromagnetic adjustment valve 25 is stabilized (step S20).

(1 meal) Command opening degree θ1 = (α1 × opening degree of current solenoid regulating valve 25 of outdoor unit 2A × suction superheat degree of outdoor unit 2A) / {(suction superheat degree of outdoor unit 2A + suction superheat degree of outdoor unit 2B) × 2}

(2 meals) Command opening degree θ2 = (α2 × opening degree of current solenoid regulating valve 25 of outdoor unit 2B × suction superheat degree of outdoor unit 2B) / {(suction superheat degree of outdoor unit 2A + suction superheat degree of outdoor unit 2B) × 2}

Here, since the outdoor units 2A and 2B have the same function, α1 and α2 are set to 1, respectively. Steps S14, S16, and S18 described above are control valves 25 for an outdoor unit having a relatively high suction superheat degree when the suction superheat degree of the suction temperature of the compressors 22 of the plurality of outdoor units 2A and 2B is different. It acts as an opening degree increasing means for increasing the opening degree of and decreasing the opening degree of the control valve 25 for the outdoor unit with a relatively low suction superheat.

(At the time of cooling operation of room (1A, 1B))

Next, a description will be given of the cooling operation of the room with the indoor units 1A and 1B. When the gas engine 20 is driven by the fuel gas, the compressor 22 is driven, and the refrigerant in the gas state of the accumulator 21 is supplied to the suction port 22i of the accumulator 21 and the suction port of the compressor 22 ( 22i), it is compressed in the compression chamber of the compressor 22. The gaseous refrigerant compressed to high temperature and high pressure is discharged from the discharge port 22i of the compressor 22 to reach the flow path 3a and the oil separator 27. In the oil separator 27, oil is separated from the refrigerant. The high temperature and high pressure refrigerant from which the oil is separated passes through the first port 28f of the four-way valve 28 as the flow path switching valve and the flow path 3k to the outdoor heat exchanger 23. And the high temperature high pressure refrigerant | coolant heat-exchanges with external air by the outdoor heat exchanger 23, and cools it to liquefy. The refrigerant (liquid state or gas-liquid two-phase state) that has undergone liquefaction reaches the expansion valve 11 through the check valve 26, the flow path 3h, the ball valve 292, the flow paths 3g, and 3f, and the expansion valve ( It expands and becomes low temperature in 11). In addition, at the time of cooling, although the solenoid regulating valve 25 is all closed, you may open it.

Thus, the refrigerant | coolant which became low in the outdoor heat exchanger 23 passes through flow paths 3g and 3f, expands with the expansion valve 11, and becomes low temperature low pressure, and reaches the indoor heat exchanger 10, and the indoor heat exchanger ( 10) heats the room with the air to cool the room. In addition, the refrigerant passes through the flow path 3e, the ball valve 291, the flow path 3c, the third port 28t of the four-way valve 28, the second port 28s of the four-way valve 28, and the flow path 3m. It returns to the return port 21r. The refrigerant returned to the accumulator 21 is accommodated in the accumulator 21 in a state separated into a liquid refrigerant and a gaseous refrigerant.

In the cooling operation, the outdoor units 2A and 2B basically perform the same function. However, the amount of refrigerant conveyed in outdoor unit 2A can be controlled by controlling the opening degree of the solenoid regulating valve 25 of outdoor unit 2A, 2B as needed. Moreover, by controlling the opening degree of the electromagnetic control valve 25 of the outdoor unit 2B, the refrigerant conveyance amount in the outdoor unit 2B can be controlled.

(Other embodiment)

7 shows another embodiment. As shown in FIG. 7, the outdoor unit is comprised of 3 units of 2A, 2B, and 2C. The outdoor units 2A, 2B and 2C have control units 4A, 4B and 4C, respectively. The outdoor unit 2A becomes a parent, and the outdoor units 2B and 2C are magnetic. Although the indoor unit is composed of three units of 1A, 1B, and 1C, the number of indoor units is not limited to this.

The controller 4A can determine the command opening degree θ1 of the control valve of the first outdoor unit 2A, the command opening degree θ2 of the control valve of the second outdoor unit 2B, and the command opening degree θ3 of the control valve of the third outdoor unit 2C based on the following equation.

(i) Command opening degree θ1 of the control valve of the first outdoor unit 2A =

α1 × Opening degree of the current control valve of the first outdoor unit 2A × {Suction superheat degree of the first outdoor unit 2A / (Suction superheat degree of the first outdoor unit 2A + Suction superheat degree of the second outdoor unit 2B + Suction superheat of the third outdoor unit 2C Degrees)] × 3

(ii) Command opening degree θ2 of the control valve of the second outdoor unit 2B =

α2 × Opening degree of the current control valve of the second outdoor unit 2B × {Suction superheat degree of the second outdoor unit 2B / (Suction superheat degree of the first outdoor unit 2A + Suction superheat degree of the second outdoor unit 2B + Suction superheat of the third outdoor unit 2C Degree)} × 3

(iii) Command opening degree θ3 of the control valve of the third outdoor unit 2C =

α3 × Opening degree of the current control valve of the third outdoor unit 2C × {Suction superheat degree of the third outdoor unit 2C / (Suction superheat degree of the first outdoor unit 2A + Suction superheat degree of the second outdoor unit 2B + Suction superheat of the third outdoor unit 2C Degree)} × 3

(Alpha) 1, (alpha) 2, and (alpha) 3 mentioned above are adjustment values and are arbitrary values of 0.7-1.3. In this case, (alpha) 1, (alpha) 2, and (alpha) 3 can be arbitrary values of 0.8-1.2 as needed. Moreover, it can be set as arbitrary value of 0.9-1.1. Since the outdoor units 2A, 2B and 2C have the same capability, alpha 1, alpha 2 and alpha 3 are each 1.

(etc)

The present invention is not limited only to the embodiment described above and shown in the drawings, and can be carried out with appropriate modifications within the scope not departing from the gist of the invention. The outdoor unit is not limited to two, three or four may be used, that is, a plurality may be used. It is not limited to the number of indoor units. Although it applies to the air conditioning apparatus operated by the compressor 22 driven by the gas engine 20, it is not limited to this, You may apply to the air conditioning apparatus operated by the compressor 22 driven by a motor.

Industrial availability

The present invention can be used for an air conditioner having a heating function.

According to the air conditioner according to the present invention, in the heating operation of the indoor unit, the excess and shortage of the refrigerant in the plurality of outdoor units is reduced, and the opening degree of the control valve in the outdoor unit is optimized. The system is stabilized.

Claims (5)

delete And a plurality of indoor units for air conditioning, a plurality of outdoor units for supplying refrigerant to the indoor units, a refrigerant piping system for connecting the outdoor units to the indoor units, and a control unit for controlling the operation of the outdoor unit. Each of the outdoor units includes a compressor having a suction port for sucking refrigerant and a discharge port for discharging compressed refrigerant, a drive source for driving the compressor, an outdoor heat exchanger connected to the compressor, and an evaporator during heating operation of the indoor unit. The opening degree which controls the flow volume of the refrigerant which flows into the said outdoor heat exchanger to become is variable, and is provided with the control valve which functions as an expansion valve at the time of a heating operation, The control unit, Suction superheat degree calculating means for obtaining a suction superheat degree of the suction temperature of the refrigerant sucked into the suction port of the compressor of each of the outdoor units; When the suction superheat degrees of the suction temperatures of the compressors of the plurality of outdoor units are different from each other, the opening degree of the control valve is increased for the outdoor unit where the suction superheat degree is relatively high, and the outdoor unit is relatively low in the suction superheat degree. An opening degree increasing means for reducing the opening degree of the control valve with respect to The outdoor unit is a first outdoor unit and a second outdoor unit, and the control unit determines the command opening degree θ1 of the control valve of the first outdoor unit and the command opening degree θ2 of the control valve of the second outdoor unit based on the following equation. Air conditioning device characterized in that. (i) Command opening degree θ1 of the control valve of the first outdoor unit = α1 × opening degree of the current control valve of the first outdoor unit × {suction superheat degree of the first outdoor unit / (suction superheat degree of the first outdoor unit + suction superheat degree of the second outdoor unit)} × 2 (ii) command opening degree θ2 of the control valve of the second outdoor unit = α2 × Opening degree of the current control valve of the second outdoor unit × {Suction superheat degree of the second outdoor unit / (Suction superheat degree of the first outdoor unit + Suction superheat degree of the second outdoor unit)} × 2 Here, alpha 1 and alpha 2 are adjustment values indicating the capacity of the outdoor unit, and are arbitrary values between 0.7 and 1.3. delete delete delete

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