KR20210015098A - A refrigerator cycle system including an inverter for controlling a compressor and an expander at the same time - Google Patents

Abstract

The present invention relates to a refrigeration cycle system which comprises: a compressor, a condenser, an expander, and a vaporizer sequentially connected in a flow direction of fluid; and an inverter electrically connected to the compressor and the expander to simultaneously control the compressor and the expander by a single control command.

Description

A refrigerator cycle system including an inverter for controlling a compressor and an expander at the same time}

The present invention relates to a compressor of an electric expander and a refrigeration system, and more specifically, to reduce the cost of the system and improve the efficiency of the system by controlling the expander and the compressor by using one inverter that replaces the expansion valve. It relates to a compressor of an electric expander and a refrigeration system.

An object of the present invention is to provide a refrigeration cycle system using an expander to reduce system cost by removing an expansion valve.

An object of the present invention is to provide a refrigeration cycle system in which an expander is simultaneously controlled by an inverter physically coupled to a compressor.

An object of the present invention is to provide a refrigeration cycle system in which the operating speed of an expander is determined based on a ratio of the number of poles of the first motor part of the compressor and the number of poles of the second motor part of the expander.

The present invention provides a refrigeration cycle system including an inverter electrically connected to the compressor and the expander so as to simultaneously control a compressor and an expander with one control command.

The present invention provides a refrigeration cycle system, characterized in that the difference between the operating speed of the compressor and the operating speed of the expander is determined based on a ratio of the number of poles of the first motor part of the compressor and the number of poles of the second motor part of the expander. .

When the operating speed of the compressor of the present invention is varied, the number of poles (n) of the first motor part and the number of poles (k) of the second motor part are varied so that the operating speed of the expander is also changed to a preset ratio (n/k). The ratio (n/k) provides a refrigeration cycle system equal to the preset ratio.

The present invention provides a refrigeration cycle system in which the preset ratio is changed based on the stroke volume of the expander.

The inverter of the present invention provides a refrigeration cycle system coupled to either side of the compressor or the expander.

The compressor of the present invention includes a first motor unit, the expander includes a second motor unit, and the inverter is coupled to any one of the compressor and the expander, and a motor provided in the other of the compressor and the expander. It provides a refrigeration cycle system that is electrically connected to the unit.

In the present invention, the number of poles of the first motor part of the compressor and the number of poles of the expander second motor part are different, so that the operating speed of the expander is varied according to the pole number ratio of the first and second motor parts.

The present invention varies the discharge flow rate of the compressor and the discharge flow rate of the expander according to the operating speed of the compressor and the expander.

In the refrigeration cycle system of the present invention, since the operation speed of the expander can be changed, there is no need for an expansion valve, so that the cost of installing the expansion valve can be reduced.

According to the present invention, a compressor and an expander are simultaneously controlled by one inverter, so that the discharge flow rate of the compressor and the discharge flow rate of the expander can be differently discharged even without an expansion valve.

The present invention has the advantage of being able to change the traveling volume to increase or decrease the discharge flow rate discharged from the compressor and expander by adjusting the number of poles of the compressor motor unit and the number of poles of the expander motor unit.

According to the present invention, when the operating speed of the compressor is varied, the operating speed of the expander can be varied rather than the constant speed, thereby enabling operation in a wide range in which the operating speed of the expander is variable.

The present invention can advantageously design the stroke volume in consideration of the efficiency of the expander according to the characteristics of the refrigeration cycle system, and thus solve the problem of designing the constant speed expander limited to the stroke volume and system flow rate of the compressor.

1 is a schematic diagram showing a refrigeration cycle system including an expander and an expansion valve in the refrigeration cycle system.
FIG. 2 shows a flow chart related to flow control of an expander and an expansion valve in the refrigeration cycle system according to FIG. 1.
FIG. 3 shows the flow rate ratio of the expander and the expansion valve according to the compressor speed (revolution speed) when the expander is not applied to the expander in the refrigeration cycle system and the expansion valve is provided.
4 is a schematic diagram of a refrigeration system comprising a compressor 100, a condenser 200, an expander 300, an evaporator 400, and an inverter 600 of the present invention.
5 is a more specific configuration of FIG. 4 in which the inverter 600 of the present invention controls the compressor 100 and the expander 300.
6 illustrates an embodiment in which a control command is transmitted to the expander 300 using the compressor inverter 730 installed in the compressor 100 of the present invention.
7 shows the discharge flow rate of the expander as the number of revolutions of the compressor of the present invention increases.
8 is a perspective view of an electric expander including a main housing, a motor part, a rotating shaft part, a frame part, and an expansion part.
9 is an exploded perspective view of an electric expander including a main housing, a motor part, a rotating shaft part, a frame part, and an expansion part.
10 is a cross-sectional view of the electric expander shown in FIGS. 8 and 9.

Hereinafter, an electric compression expander and an air conditioning system including the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the following description, descriptions of some constituent elements may be omitted to clarify features of the present invention.

1 is a schematic diagram showing a refrigeration cycle system including an expander and an expansion valve in the refrigeration cycle system.

The refrigeration cycle system is a compressor 100 that converts a low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant, and changes the high-temperature and high-pressure gaseous refrigerant changed in the compressor 100 to a high-temperature, high-pressure liquid state. The condenser 200 to change the high-temperature and high-pressure liquid refrigerant changed in the condenser 200 into a low-temperature, low-pressure liquid refrigerant and the expander 300 to change the low-temperature and low-pressure liquid refrigerant changed in the expander 300 into a gaseous state. It consists of an evaporator 400 that absorbs external heat while making it.

And each of the components are connected by a refrigerant pipe 700. One side of the expansion valve 500 is connected to the outlet refrigerant pipe of the condenser 200 and the other side is connected to the outlet refrigerant pipe of the expander 300. The compressor 100 is a component operated by the inverter 500.

FIG. 2 shows a flow chart related to flow control of an expander and an expansion valve in the refrigeration cycle system according to FIG. 1.

3 shows the flow rate ratio of the expander and the expansion valve according to the compressor speed (rotation speed) when the expander is not applied to the expander in the refrigeration cycle system and the expansion valve is provided.

3 shows the flow rate of the compressor (comp.mdot), the flow rate of the expansion valve (EXV.mdot), the flow rate of the expander (EXP.mdot), and the flow rate of the expansion valve (Traditional EXV.) before application of the expander according to the number of revolutions (rpm). . The horizontal axis is the compressor speed (rpm), and the vertical axis is the mass flow rate (dimensionless) (of the discharged refrigerant).

2, m _trad is the flow rate of the expansion valve before the expander is operated (the amount of opening), m _exp is the flow rate of the expander with a maximum efficiency or a constant flow rate, and m _exv is the flow rate of the expansion valve used by arranging the expander and the valve in parallel. The (opening degree) is shown respectively.

If the expander flow rate (m _exp ) is greater than or equal to the expansion valve flow rate (opening degree) (m _trad ) (m _exp ≥ m _trad ), the expander stops working.

Change the system conditions so that the flow rate of the expansion valve used in parallel (opening amount) (m _exv ) and the flow rate of the expansion valve before applying the expander (opening amount) (m _trad ) are the same.

If the expander flow rate (m _exp ) is less than the expansion valve flow rate (opening amount) (m _trad ) before the expander is applied (m _exp <m _trad ), the expander is operated.

Change the system condition so that the sum of the flow rate of the expander (m _exp ) and the flow rate of the expansion valve (m _exv ) is the same as the flow rate of the expansion valve (m _trad) before applying the expander (m _exp + m _exv = m _trad ).

As the number of revolutions of the compressor increases, the discharge flow rate of the compressor is increasing as shown in the graph indicated by ●.

Therefore, the expansion valve flow rate to be used in parallel as indicated by ■, the expansion valve, the flow rate (m _exv) again decreases while the expansion valve, the flow rate (m _exv) increases with the number of revolutions of the compressor, the compressor is more than the number of revolutions constant Notice the increase.

As the flow rate of the expansion valves used in parallel (m _exv ) increases and decreases, the flow rate of the expander (m _exp ) is increased as shown in the graph indicated by ▲ to compensate for the same as the flow rate of the expansion valve (m _trad ) before the expansion of the graph indicated by ▼. I'm making it.

Therefore, since the expander always operates at a constant speed, the range of use of the expander is small, and the expansion valve is required in a region where the expander is not driven or the flow rate is insufficient, thereby increasing additional cost for installation and operation of the expansion valve.

Since the discharge flow rate of the expander operating at a constant speed is directly connected to the refrigeration cycle system, the stroke volume is limited when the expander is designed.

Therefore, in the present invention, the inverter gives a command to the compressor and the expander at the same time, but due to the characteristics of the expander applied to the system, the discharge flow rate of the compressor and the discharge flow rate of the expander are considered to be different for forming the pressure of the system.

Due to the nature of the refrigeration cycle system, it is necessary to form a pressure difference in the expander. Therefore, a control method in which the discharge flow rate of the compressor and the discharge flow rate of the expander are different was considered.

Assuming that the number of poles of the first motor part of the compressor is n and the number of poles of the second motor part of the expander is k, the operating speed of the expander may be varied at an n/k ratio. The discharge flow rate of the expander is proportional to the operating speed of the expander.

Meanwhile, the first motor unit may be used as the first motor and the second motor unit may be used as the second motor.

When the operating speed of the expander is varied by an n/k ratio, the discharge flow rate of the expander can be discharged by n/k.

For example, if the number of poles of the first motor part of the compressor is n and the number of poles of the second motor part of the expander is k, the flow rate may be discharged from the expander at a ratio of n/k.

As the operating speed of the compressor is changed, the operating speed of the expander is varied together, so that the operating range is widened, and the effect of removing the expansion valve can be obtained.

Here, "stroke volume" may mean the flow rate of a compressor or expander by driving the motor unit.

By adjusting the number of poles of the first and second motor parts of the compressor or expander, the operating speed of the expander can be varied. As the operating speed of the expander is varied, the moving volume may be changed.

Therefore, the present invention is not limited to the stroke volume of the expander, it is possible to increase or decrease the stroke volume by adjusting the number of poles of the first and second motor parts. Hereinafter, a refrigeration cycle system will be described in detail with reference to the drawings.

4 is a schematic diagram of a refrigeration cycle system composed of a compressor 100, a condenser 200, an expander 300, an evaporator 400, and an inverter 600.

The present invention is applicable not only to a refrigeration and air conditioning system, but also to a feed pump or a Rankine cycle using a pump and an organic Rankine cycle.

Referring to Figure 4, the refrigeration cycle system of the present invention is composed of a compressor 100, a condenser 200, an expander 300, an evaporator 400, and an inverter 600.

The inverter 600 serves as an integrated central control unit that simultaneously issues one control command to the compressor 100 and expander 300.

In the refrigeration cycle system, the discharge flow rate of the compressor 100 and the discharge flow rate of the expander 300 may be differently discharged.

The expander 300 has an operating speed corresponding to the ratio of the number of poles of the first and second motor parts of the compressor 100 and the expander 300.

When the operating speed of the compressor 100 changes according to the pole number ratio of the first and second motor parts, the operating speed of the expander 300 is varied according to the pole number ratio of the first and second motor parts. The operating speed of the expander 300 is varied according to the pole number ratio of the first and second motor parts. Therefore, the operating range of the expander is widened.

According to the operating speed (rotation speed) of the compressor by the command of one inverter 600 that controls the compressor 100 and the expander 300 at the same time, the operating speed of the expander 300 is proportional to the pole number ratio of the first and second motor parts. Depends on

FIG. 4 is illustrated in a configuration in which an inverter 600 serving as an integrated control unit for giving commands to the compressor 100 and the expander 300 is separately installed, but is not limited thereto.

FIG. 5 is a more detailed configuration of FIG. 4 in which an inverter 600 separately installed in the refrigeration cycle system controls the compressor 100 and the expander 300.

The inverter 600 of the refrigeration cycle system may simultaneously drive the compressor 100 and the expander 300 with one command.

As shown in FIGS. 5 and 6, the compressor 100 is provided with a first motor unit 710, and the expander 300 is provided with a second motor unit 720.

The inverter 600 is electrically connected to the first motor unit 710 of the compressor 100.

In addition, the inverter 600 is electrically connected to the second motor unit 720 of the expander 300.

The inverter is disposed at a position spaced apart from the compressor and the expander, is electrically connected to the first motor unit of the compressor, and may be electrically connected to the second motor unit of the expander.

An inverter physically coupled to the compressor may be electrically connected to the second motor unit of the expander.

In addition, the inverter physically coupled to the expander may be electrically connected to the first motor unit of the compressor.

6 shows a refrigeration cycle system including an inverter 600 to which the compressor 100 and the expander 100 are electrically connected.

Referring to FIG. 6, the compressor inverter 730 physically coupled to the compressor 100 is electrically connected to the first motor unit 710 of the compressor and the second motor unit 720 of the expander 300.

The compressor inverter 730 is electrically connected to the compressor and the expander so as to simultaneously control the compressor and the motor units 710 and 720 of the expander with one control command.

The inverter simultaneously applies one control command to the first motor part of the compressor and the second motor part of the expander, and discharges the discharge flow rate of the compressor and the expander according to the rotational speed of the first motor part and the first motor part. The flow rate is discharged differently.

The inverter may change the rotation speed of the first motor unit and the second motor unit so that the discharge flow rates of the compressor and the expander are differently discharged with one control command.

A pressure difference occurs in the expander due to the difference between the discharge flow rate of the compressor and the discharge flow rate of the expander.

In the present invention, as shown in Figs. 4, 5 and 6, the refrigeration cycle system simultaneously controls the compressor 100 and the expander 300 with one command using one inverter 600.

By applying a command of one inverter to the compressor and expander, the first motor unit and the second motor unit may be simultaneously controlled and operated.

In the present invention, by applying a command of one inverter to the compressor and the expander, the discharge flow rate of the compressor and the discharge flow rate of the expander can be differently discharged. As a result, a pressure differential applied to the refrigeration cycle system occurs in the expander.

In order to make the discharge flow rate of the compressor different from the discharge flow rate of the expander, the number of poles of the motor part installed in the compressor and the number of poles of the motor part installed in the expander may be reduced or increased to make the refrigerant discharge flow rate different.

The discharge flow rate of the compressor and the discharge flow rate of the expander may be varied according to the operating speed of the compressor and expander.

When the operating speed of the compressor is changed, the operating speed of the expander may also vary, so that the operating range of the expander may be widened.

The expander rotates by a pole ratio of the first motor unit of the compressor and the expander, so that the refrigerant discharge flow rate may be varied. The operating speed of the expander may be changed by the pole number ratio of the first and second motor parts of the compressor and the expander.

For example, a speed command is given to the inverter by varying the number of poles of the motor part.

At this time, if the operating speed of the compressor 100 is r, the operating speed of the compressor 100 is r, and the operating speed of the expander 300 is (r) X (n/k). Here, n is the number of poles of the motor part of the compressor 100, and k is the number of poles of the motor part of the expander 300. The number of motor poles is determined by the number of fixed magnets.

Hereinafter, the flow rate ratio of the compressor and the expander according to the number of revolutions when the expansion valve is not employed but only the expander is applied. As shown in FIG. 7, the flow rate of the compressor of the refrigeration cycle system is denoted by ●, and the flow rate of the expansion valve. When marked with ▲, an expander was applied to this system.

The compressor flow rate of the refrigeration cycle system is indicated by a graph marked with ●, and the refrigeration cycle system using an expansion valve requires the expansion valve flow rate (m _trad ) indicated by ▼.

If the expander is designed to match the discharge flow rate of the expander of the refrigeration cycle system to the 1/2 stroke volume of the discharge flow rate of the compressor, the compressor 100 may be configured with a 4-pole motor unit and the expander 300 may be configured with an 8-pole motor unit.

As the number of revolutions of the compressor increases, the discharge flow rate of the compressor is increasing as shown in the graph indicated by ●.

If an expansion valve is used, the expansion valve flow rate (m _trad ) indicated by ▼ is required.

However, in the present invention, only the expander can obtain the same discharge flow rate through the expander flow rate (m _exp ) indicated by ▲.

In the present invention, when the operating speed of the compressor is varied, the ratio of the number of poles (n) of the first motor part of the compressor and the number of poles (k) of the second motor part of the expander so that the operation speed of the expander is also varied by a preset ratio (a) ( n/k) can obtain a driving speed equal to the preset ratio (a=n/k).

When the operating speed of the expander is changed by n/k, the discharge flow rate of the expander may also be changed to n/k.

When the number of poles of the second motor part of the expander is reduced or increased, the expander rotates by the number of poles of the first and second motor parts of the compressor and the expander.

Therefore, when the operating speed of the compressor is changed, the operating speed of the expander can also be varied, so that the operating range of the expander can be widened.

The refrigerant discharge flow rate of the expander may also vary according to the change of the operating speed of the expander.

Therefore, in the present invention, it can be seen that even if the expansion valve is removed or the expander and the compressor are controlled using a single inverter, the same discharge flow rate can be obtained from the expander.

The present invention controls the expander and the compressor using one inverter, and removes the expansion valve used in the refrigeration cycle system, thereby reducing the equipment cost of the refrigeration cycle system.

The electric expander 300 used in the present invention will be described in detail below with reference to 8, 9, and 10.

The electric expander is a positive displacement expander having a rotor that is rotationally driven by the expansion energy of an operating medium.

8 is a perspective view of an electric expander 300 including a main housing 1100, a motor unit 1200, a rotating shaft unit 1300, a frame unit 1400, and an expansion unit 1500.

9 is an exploded perspective view of the electric expander 300 including a main housing 1100, a motor unit 1200, a rotation shaft unit 1300, a frame unit 1400, and an expansion unit 1500.

10 is a cross-sectional view of the electric expander shown in FIGS. 8 and 9.

The electric expander 300 of the present invention includes a main housing 1100, a motor part 1200, a rotating shaft part 1300, a frame part 1400, and an expansion part 1500. The electric expander 300 may include an inverter unit for applying power and control signals to the motor unit 200.

The main housing 1100 forms a body portion of the electric expander 300, and a space is formed therein. A device provided in the electric expander 300 may be accommodated in the space.

The frame unit 1400 positioned at one side of the main housing 1100 connects the main housing 1100 and the fixed scroll 1520 of the expansion unit 1500 in fluid communication.

The outer diameters of the main housing 1100 and the frame unit 1400 may be the same.

The outer surface of the main housing 1100 and the outer surface of the frame unit 1400 may be disposed on the same surface. The frame unit 1400 may not be provided separately, and the main housing 1100 may be configured to perform the function of the frame unit 1400.

A discharge part 600 communicating with the main housing 1100 is positioned on a side opposite to the frame part 1400. The refrigerant expanded in the expansion unit 1500 may flow into the discharge unit 1600 through the frame unit 1400 and the main housing 1100.

The main housing 1100 includes a motor chamber 1110 and a discharge port 1120.

A stator 1210 is disposed outside the motor unit 1200 and a rotor 1220 is disposed inside the motor unit 1200.

The expanded refrigerant may be introduced into the main housing 1100 through the frame unit 1400 and then may enter the exhaust passage 1610 of the discharge unit 1600 through the discharge port 1120.

The motor unit 1200 may be configured to operate by receiving power and a control signal from a control unit (inverter) outside the electric expander 300.

The stator 1210 may include a plurality of coils (not shown), and may be configured to flow a current in any one of the U-phase, V-phase, and W-phase. The stator 1210 forms the outside of the motor unit 1200. The rotor 1220 is accommodated to be spaced apart from the stator 1210 by a predetermined distance in the hollow portion.

The rotation shaft unit 1300 coupled through the motor unit 1200 transmits the rotational force generated by the motor unit 1200 to the expansion unit 1500.

One side of the rotary shaft portion 1300 is coupled to the orbiting scroll 1510 of the expansion portion 1500 and rotates as a unit. The rotating shaft part 1300 may be rotatably supported by a slewing bearing. The rotation shaft unit 1300 may be disposed to have the same central axis as the motor unit 1200.

The frame unit 1400 includes a back pressure chamber 1410 and a fence unit 1420.

The back pressure chamber 1410 is a space into which a part of the refrigerant expanded in the expansion unit 1500 is introduced.

The back pressure chamber 1410 communicates with the expansion unit 1500. Specifically, the back pressure chamber 1410 communicates with the refrigerant opening 1513 of the orbiting scroll 1510.

The back pressure chamber 1410 is formed by a space adjacent to the rotation shaft portion 1300 in the frame portion 1400. The back pressure chamber 1410 may be defined as a space surrounded by the rotating shaft portion 1300, the fence portion 1420, and the turning plate portion 1511.

The refrigerant flowing into the back pressure chamber 1410 is configured to apply back pressure to the orbiting scroll 1510. The refrigerant introduced into the back pressure chamber 1410 applies a pressure in a direction toward the fixed scroll 1520 to the orbiting scroll 1510.

As the compressed refrigerant flows into the expansion unit 1500, the orbiting scroll 1510 is pushed in a direction opposite to the fixed scroll 1520 by the pressure of the compressed refrigerant.

The fence portion 1420 is formed inside the frame portion 1400 and partitions the back pressure chamber 1410.

The expansion unit 1500 is rotated by the rotational force generated by the motor unit 1200 to expand the refrigerant.

The orbiting scroll 1510 may be coupled to the rotation shaft part 1300 by a pin disposed to be eccentric with the rotation shaft part 1300. The orbiting scroll 1510 is rotated eccentrically with respect to the rotation shaft portion 1300.

On the other hand, the fixed scroll 1520 may be configured to have the same central axis as the rotation shaft part 1300. The orbiting scroll 1510 may be rotated eccentrically with respect to the fixed scroll 1520. By eccentric rotation of the orbiting scroll 1510, the refrigerant may expand in the space between the orbiting wrap 1512 and the fixed wrap 1522.

The orbiting scroll 1510 includes an orbiting plate portion 1511, an orbiting wrap 1512, and a refrigerant opening 1513.

The refrigerant flowing into the refrigerant inlet 1523 flows into the space between the orbiting wrap 1512 and the fixed wrap 1522 and expands. Some of the expanded refrigerant flows into the back pressure chamber 1410, and the remaining refrigerant is moved to the discharge unit 6600 through the frame unit 1400 and the main housing 1100.

The discharge unit 1600 is configured to discharge not only the expanded refrigerant but also oil mixed with the refrigerant. The discharge unit 1600 communicates with an evaporation refrigerant flow path 1744 that communicates the evaporator 1730 and the compressor 1710.

The discharge part 1600 includes an exhaust flow path 1610, an oil separator 1620, an oil chamber 1630, and a communication part 1640.

The exhaust passage 1610 communicates with the oil chamber 1630. Inside the discharge unit 1600, the exhaust flow path 1610 may be located above the oil chamber 1630.

The oil mixed with the expanded refrigerant flowing along the exhaust passage 1610 is separated by the oil separator 1620 and may be dropped and moved to the oil chamber 1630.

A refrigerant exhaust port 1612 is formed at one end of the exhaust passage 1610 and an upper end of the exhaust passage 1610. The refrigerant exhaust port 1612 communicates with the exhaust passage 1610 and the outside of the discharge unit 1600. The refrigerant exhaust port 1612 may be formed in a form of a through hole communicating the inside and the outside of the discharge unit 1600.

The exhaust passage 1610 is a passage through which the refrigerant expanded in the expansion unit 1500 is discharged to the outside of the electric expander 300.

The oil separator 1620 is configured to separate oil mixed with the expanded refrigerant introduced into the discharge unit 1600.

The oil chamber 1630 is a part in which oil separated from a mixed fluid of refrigerant and oil is collected.

The communication unit 1640 communicates the inner space of the main housing 1100 and the discharge unit 1600.

The term "refrigerant" used in the description of the present invention means a medium that takes heat from a low temperature object and transports it to a high temperature object. The refrigerant may be carbon dioxide (CO2), R134a or R1234yf.

The term “oil” is used for the purpose of preventing or dispersing heat or abrasion generated in frictional parts of a machine, and refers to a fluid that can be mixed or separated with a refrigerant, and the oil may be a lubricant.

In the present invention, the operating speed of the expander can be changed, and accordingly, the expander is driven in all sections, so that the efficiency of the system is increased, and the expansion valve part is eliminated, thereby reducing the cost of the system.

Further, in the case of a constant speed expander, the design is limited to the stroke volume of the compressor and the system flow rate, but in the present invention, various designs of the stroke volume are advantageously possible in consideration of the efficiency of the expander according to the system characteristics.

In the present invention, the inverter issues one command to the compressor and the expander at the same time, but due to the characteristics of the expander applied to the system, the discharge flow rate of the compressor and the discharge flow rate of the expander may be different to form the pressure of the system.

Even if the number of poles of the motor installed in the expander, which is a rotating shaft that rotates using the shaft, is reduced or increased to reduce the same operating speed to the compressor, the expander can rotate as much as the number of poles of the compressor and expander to change the discharge flow rate.

By varying the operating speed of the expander together, the operating range is widened, and equipment cost is reduced compared to the system by using the expander and the expansion valve at the same time, and the efficiency is increased compared to the case of a constant speed expander.

When the expander operates at a constant speed, the discharge flow rate of the expander is directly connected to the system, so the stroke volume is limited when designing the expander.

However, the present invention is not limited to the stroke volume of the expander, and it is possible to increase or decrease the stroke volume by adjusting the number of poles of the motor unit, so that the design can be advantageously suited to the applied system.

Although the above description has been made with reference to preferred embodiments of the present invention, those of ordinary skill in the art to which the present invention pertains can variously modify the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims It will be appreciated that it can be modified and changed.

100: compressor
200: condenser
300: inflator
400: evaporator
500: expansion valve
600: inverter
710: first motor unit
720: second motor unit
730: compressor inverter
1100: main housing
1200: motor unit
1210: stator
1220: rotor
1300: rotating shaft part
1400: frame part
1410: back pressure chamber
1420: fence part
1500: expansion part
1510: orbiting scroll
1520: fixed scroll
1523: refrigerant inlet
1600: discharge unit
1610: exhaust flow path
1620: oil separator
1630: oil chamber
1640: communication department

Claims (9)

A compressor, a condenser, an expander, and an evaporator sequentially connected along the flow direction of the fluid to form a refrigeration cycle; And
And an inverter electrically connected to the compressor and the expander to simultaneously control the compressor and the expander with a single control command. The method of claim 1,
The compressor has a first motor,
The expander has a second motor,
A refrigeration cycle system, characterized in that the difference between the operating speed of the compressor and the operating speed of the expander is determined based on a ratio of the number of poles of the first motor and the number of poles of the second motor. The method of claim 2,
When the operating speed of the compressor is varied, the ratio of the number of poles (n) of the first motor and the number of poles (k) of the second motor (n/k) so that the operating speed of the expander is also changed to a preset ratio (a). ) Is the same as the preset ratio (a=n/k) of the refrigeration cycle system.
The method of claim 3,
The refrigeration cycle system that the preset ratio is changed based on the stroke volume of the expander. The method of claim 1,
The inverter is a refrigeration cycle system coupled to either side of the compressor or the expander. The method of claim 5,
The compressor has a first motor part, the expander has a second motor part,
The inverter is coupled to one of the compressor and the expander, the refrigeration cycle system electrically connected to a motor unit provided in the other of the compressor and the expander. The method of claim 5,
The compressor has a first motor part, the expander has a second motor part,
The inverter is physically coupled to the compressor and electrically connected to the second motor unit. The method of claim 5,
The compressor has a first motor part, the expander has a second motor part,
The inverter is physically coupled to the expander and electrically connected to the first motor unit. The method of claim 1,
The compressor has a first motor part, the expander has a second motor part,
The inverter is disposed at a position spaced apart from the compressor and the expander, and is electrically connected to the first motor unit and the second motor unit, respectively.

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