EP2354728B1

EP2354728B1 - Refrigerant system

Info

Publication number: EP2354728B1
Application number: EP10197204.0A
Authority: EP
Inventors: Doyong Ha; Baikyoung Chung; Sedong Chang; Junggyu Park
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2010-02-08
Filing date: 2010-12-28
Publication date: 2019-07-03
Anticipated expiration: 2030-12-28
Also published as: EP2354728A2; KR101146409B1; US20110192183A1; KR20110092120A; EP2354728A3

Description

BACKGROUND

The present disclosure relates to a refrigerant system in which a refrigerant cycle is performed.
In general, a refrigerant system is a device that cools or heats an interior space by performing a refrigerant cycle including compression, condensation, expansion and evaporation of refrigerant.
The refrigerant system includes an indoor unit in which a refrigerant is heat-exchanged with indoor air and an outdoor unit in which a refrigerant is heat-exchanged with outdoor air. The indoor unit includes an indoor heat exchanger for performing heat-exchange between the refrigerant and the indoor air, a fan blowing the indoor air, and a motor rotating the fan. The outdoor includes an outdoor heat exchanger for performing heat-exchange between the refrigerant and the outdoor air, a fan for blowing the outdoor air, a motor for rotating the fan, a compressor for compressing the refrigerant, an expander for expanding the compressed refrigerant, and a 4-way valve for diverting a flow of the refrigerant.
When an interior space is cooled, the indoor heat exchanger operates as an evaporator, and the outdoor heat exchanger operates as a condenser. When the interior space is heated, the indoor heat exchanger operates as a condenser, and the outdoor heat exchanger operates as an evaporator. The 4-way valve diverts a refrigerant flow direction to switch the cooling and heating operations.
EP 0 639 745 shows an example of a refrigerator with two outdoor units, three indoor units, a high-pressure gas line, a low pressure gas line, an indoor gas pipe, branch low pressure pipes, a main liquid line, an indoor liquid pipe, a high pressure valve and a high pressure bypass passage.

SUMMARY

The current invention provides a refrigerant system with the features of claim 1. Embodiments provide a refrigerant system capable of minimizing noise generated when an operation mode is switched.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a view of a state in which cooling and heating operations are simultaneously performed in a refrigerant system according to a first embodiment.
Fig. 2 is a view of a refrigerant flow in a case where an indoor unit of the refrigerant system is operated in a cooling mode according to the first embodiment.
Fig. 3 is a view of a refrigerant flow in a case where the indoor unit of the refrigerant system is switched from the cooling mode or a stop mode to a heating mode according to the first embodiment.
Fig. 4 is a view of a refrigerant flow in a case where the indoor unit of the refrigerant system is operated in a heating mode according to the first embodiment.
Fig. 5 is a block diagram of the refrigerant system according to the first embodiment.
Fig. 6 is a flowchart illustrating a process in which the refrigerant system is switched into the heating mode according to the first embodiment.
Fig. 7 is a block diagram of a refrigerant system according to a second embodiment.
Fig. 8 is a flowchart illustrating a process in which the refrigerant system is switched into a heating mode according to the second embodiment.
Fig. 9 is a block diagram of a refrigerant system according to a third embodiment.
Fig. 10 is a flowchart illustrating a process in which the refrigerant system is switched into a heating mode according to the third embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
Fig. 1 is a view of a state in which cooling and heating operations are simultaneously performed in a refrigerant system according to a first embodiment.
Referring to Fig. 1, a refrigerant system includes an outdoor unit 1 disposed in an outdoor space and exposed to outdoor air, a plurality of indoor units 2 disposed in an indoor space and exposed to indoor air, a distributor 3 connecting the outdoor unit 1 to the plurality of indoor units 2, and a refrigerant tube through which a refrigerant flows among the outdoor unit 1, the indoor units 2, and the distributor 3.
In detail, the outdoor unit 1 includes an outdoor heat exchanger 11 in which the indoor air and the refrigerant are heat-exchanged with each other, a compressor 12 compressing the refrigerant, a flow switch part 13 switching a flow direction of the refrigerant discharged from the compressor 12, and an outdoor expansion part 14 selectively expanding the refrigerant flowing into the outdoor heat exchanger 11.
The outdoor heat exchanger 11 is exposed to the outdoor air within the outdoor unit 11. The outdoor heat exchanger 11 may selectively serve as an evaporator evaporating the refrigerant or a condenser condensing the refrigerant according to operation modes of the refrigerant system.
The compressor 12 includes a constant speed compressor 121 operated at a constant speed to compress the refrigerant and an inverter compressor 122 operated at a variable speed to compress the refrigerant. The constant speed compressor 121 and the inverter compressor 122 are parallely connected to each other.
The flow switch part 13 is disposed in the refrigerant tube corresponding to a discharge side of the compressor 12. The flow switch part 13 allows the refrigerant tube connected to an inflow side of the compressor 12 to selectively communicate with the refrigerant tube connected to the outdoor heat exchanger 11 and the refrigerant tube corresponding to the discharge side of the compressor 12. That is, the refrigerant discharged from the compressor 12 may flow into the outdoor heat exchanger 11 and vice versa according to the switching operation of the flow switch part 13.
The outdoor expansion part 14 is disposed in the refrigerant tube corresponding to a position adjacent to the outdoor heat exchanger 11. Particularly, the outdoor expansion part 14 is disposed in the refrigerant tube connecting the outdoor heat exchanger 11 to the distributor 3. When the refrigerant system is operated to allow the outdoor heat exchanger 11 to serve as the evaporator, the refrigerant discharged from the distributor 3 may be expanded while it passes through the outdoor expansion part 14 before it flows into the outdoor heat exchanger 11.
Furthermore, the outdoor unit 1 may further include an outdoor fan (not shown) for forcibly blowing the outdoor air toward the outdoor heat exchanger 11 and an outdoor motor (not shown) for rotating the outdoor fan.
Each of the indoor units 2 includes an indoor heat exchanger 23 in which the indoor air and the refrigerant are heat-exchanged with each other and an indoor expansion part 24 for expanding the refrigerant flowing into the indoor heat exchanger 23. That is, the refrigerant system includes a plurality of the indoor heat exchangers 23 and a plurality of the indoor expansion parts 24 corresponding to the plurality of indoor heat exchangers 23 as a whole.
The distributor 3 is connected to both the outdoor unit 1 and the plurality of indoor units 2. The distributor distributes the refrigerant discharged from the outdoor unit 1 to the plurality of indoor units. Also, the distributor 3 switches a flow direction of the refrigerant within the indoor units 2 according to the operation mode of the refrigerant system.
The refrigerant tube includes a high-pressure tube 42 guiding the refrigerant discharged from the compressor 12 to the distributor 3, a low-pressure tube 43 guiding the refrigerant evaporated by at least one of the indoor units 2 to the compressor 12, and a liquid refrigerant tube 41 through which the refrigerant condensed within the indoor units 2 or the outdoor unit1 flows, and an indoor unit tube 44 connecting the distributor 3 to the indoor units 2.
The high-pressure tube 42, the low-pressure tube 43, and the liquid refrigerant tube 41 connect the outdoor unit 1 to the distributor 3. Also, the high-pressure tube 42 is branched from the refrigerant tube corresponding to the discharge side of the compressor 12 to extend up to the inside of the distributor 3. The low-pressure tube 43 is connected to the refrigerant tube corresponding to the inflow side of the compressor 12 to extend up to the inside of the distributor 3. Also, the liquid refrigerant tube 41 is connected to the outdoor expansion part 14 to extend up to the inside of the distributor 3.
The distributor 3 includes a plurality of high-pressure branch tubes 45 guiding the refrigerant within the high-pressure tube 42 to the plurality of indoor heat exchangers 23, a plurality of low-pressure branch tubes 47 guiding the refrigerant within the plurality of indoor heat exchangers 23 to the low-pressure tube 43, and high-pressure and low- pressure valves 31 and 32 respectively selectively interrupting the refrigerant flows within the high-pressure and low- pressure branch tubes 45 and 47.
That is, the high-pressure branch tube 45 is branched from the high-pressure tube 42, and the low-pressure branch tube 47 is branched from the low-pressure tube 43. The high-pressure valve 31 and the low-pressure valve 32 are disposed in the high-pressure branch tube 45 and the low-pressure branch tube 47, respectively.
The indoor unit tube 44 has one end connected to the liquid refrigerant tube 41 and the other end connected to both the high-pressure branch tube 45 and the low-pressure branch tube 47. Also, the indoor heat exchanger 23 and the indoor expansion part 24 are disposed on the indoor unit tube 44. That is, the indoor unit tube 44 connects the indoor heat exchanger 23 to the high-pressure and low- pressure branch tubes 45 and 47.
Also, according to the operation mode of the indoor unit 2, the refrigerant of the liquid refrigerant tube 41 may sequentially pass through the indoor expansion part 24 and the indoor heat exchanger 23 to flow into the low-pressure branch tube 47, or the refrigerant of the high-pressure branch tube 45 may sequentially pass through the indoor heat exchanger 23 and the indoor expansion part 24 to flow into the liquid refrigerant tube 41.
The refrigerant tube may further include a high-pressure bypass tube 46 allowing the refrigerant of the high-pressure tube 42 to bypass the high-pressure valve 31, thereby guiding the refrigerant to the indoor unit tube 44. A high-pressure valve 33 for selectively interrupting a refrigerant flow within the high-pressure bypass tube 46 is disposed in the high-pressure bypass tube 46.
In detail, the high-pressure bypass tube 46 has one end disposed at the high-pressure branch tube 45 between the high-pressure tube 42 and the high-pressure valve 31 and the other end disposed at the indoor unit tube 44. Thus, in a state where the high-pressure bypass tube 46 is opened, the refrigerant of the high-pressure tube 42 may flow into the indoor unit tube 44 through the high-pressure bypass tube 46.
The high-pressure bypass valve 33 has a capacity less than that of the high-pressure valve 31. That is, a flow amount per unit time of the refrigerant passing through the high-pressure bypass valve 33 in a state where the high-pressure bypass valve 33 is opened is less than that of the refrigerant passing through the high-pressure valve 31 in a state where the high-pressure valve 31 is opened.
Thus, in the state where the high-pressure bypass valve 33 is opened, the refrigerant of the high-pressure tube 42 may further slowly flow into the indoor unit tube 44 through the high-pressure bypass tube 46 when compared to the state in which the high-pressure valve 31 is opened.
The indoor unit 2 may further include an indoor fan (not shown) for forcibly blowing the indoor air toward the indoor heat exchanger 23 and an indoor motor (not shown) for rotating the indoor fan.
Hereinafter, a refrigerant flow in the refrigerant system according to an embodiment will be described in detail with reference to accompanying drawings.
Referring to Fig. 1, in the refrigerant system, the plurality of indoor units 2 may be operated in different operation modes simultaneously. Fig. 1 illustrates a refrigerant flow in a case where the outdoor heat exchanger 11 serves as a condenser, a first indoor unit 21 is operated in a heating mode, and a second indoor unit 22 is operated in a cooling mode.
In detail, a portion of the refrigerant discharged from the compressor 12 is introduced into the outdoor heat exchanger 11 by the flow switch part 13. The remaining portion of the refrigerant discharged from the compressor 12 is introduced into the high-pressure tube 42.
The refrigerant flowing into the outdoor heat exchanger 11 emits heat to the outdoor air while passing through the outdoor heat exchanger 11, thereby being condensed. Here, even through the refrigerant passes through the outdoor expansion part 14, the refrigerant passes through the outdoor expansion part 14 without changing a phase thereof because the outdoor expansion part 14 is fully opened.
The refrigerant flowing into the liquid refrigerant tube 41 flows toward the first indoor unit 21 along the indoor unit tube 44 of the first indoor unit 21. The refrigerant flowing into the first indoor unit 21 is expanded while passing through the indoor expansion part 24 of the first indoor unit 21. The refrigerant passing through the indoor expansion part 24 absorbs heat from the indoor air while passing through the indoor heat exchanger 23 of the first indoor unit 21, thereby being evaporated. That is, the first indoor unit 21 is operated in the cooling mode.
The refrigerant passing through the indoor heat exchanger 23 of the first indoor unit 21 is introduced into the low-pressure tube 43 along the low-pressure branch tube 47 corresponding to the first indoor unit 21. Here, the high-pressure valve 31 and the high-pressure bypass valve 33 corresponding to the first indoor unit 21 are maintained in a closed state, and the low-pressure valve 32 corresponding to the first indoor unit 21 is maintained in an opened state. Therefore, the refrigerant discharged from the indoor heat exchanger 23, that is, the first indoor unit 21 may smoothly flow into the low-pressure tube 43.
The refrigerant flowing into the low-pressure tube 43 flows into the compressor 12 and then is compressed again while passing through the compressor 12.
The refrigerant discharged from the compressor 12 to flow into the high-pressure tube 42 passes through the high-pressure branch tube 45 corresponding to the second indoor unit 22 to flow into the indoor unit tube 44 of the second indoor unit 22. At this time, the low-pressure valve 32 and the high-pressure bypass valve 33 corresponding to the second indoor unit 22 are maintained in a fully closed state, and the high-pressure valve 31 corresponding to the second indoor unit 22 is maintained in a fully opened state. Therefore, the refrigerant passed through the high-pressure tube 42 and the high-pressure branch tube 45 may smoothly flow to the indoor heat exchanger 23, that is, the second indoor unit 22.
The refrigerant emits heat to the indoor air while it passes through the indoor heat exchanger 23 of the second indoor unit 22, thereby being condensed. That is, the second indoor unit 22 is operated in the heating mode. The refrigerant passed through the indoor heat exchanger 23 flows into the liquid refrigerant tube 41 through the indoor unit tube 44. Here, even though the refrigerant passed through the indoor heat exchanger 23 passes through the indoor expansion part 24, the refrigerant passes through the indoor expansion part 24 without changing a phase thereof because the indoor expansion part 24 is fully opened.
The refrigerant flowing into the liquid refrigerant tube 41 is mixed with the refrigerant flowing from the outdoor unit 1 to the distributor 3. As described above, the mixed refrigerant passes through the first indoor unit 21, flows into the compressor 12 through the low-pressure tube 43, and is compressed again.
The outdoor heat exchanger 11 may function as a condenser or an evaporator according to the operation mode of the indoor units 2. For example, the outdoor heat exchanger 11 functions as the condenser when all the indoor units 2 are operated in the cooling mode, or the outdoor heat exchanger 11 functions as the evaporator when all the indoor units 2 are operated in the heating mode.
When the outdoor heat exchanger 11 functions as the condenser, the flow switch part 13 is configured to communicate between the refrigerant tube connected to the outdoor heat exchanger 11 and the refrigerant tube connected to the discharge side of the compressor 12. When the outdoor heat exchanger 11 functions as the evaporator, the flow switch part 13 is configured to communicate between the refrigerant tube connected to the outdoor heat exchanger 11 and the refrigerant tube connected to the intake side of the compressor 12.
With respect to the liquid refrigerant tube 41, the refrigerant of the liquid refrigerant tube 41 flows toward the distributor 3 and the indoor units 2 when the outdoor heat exchanger 11 functions as the condenser. On the other hand, when the outdoor heat exchanger 11 functions as the evaporator, the refrigerant of the liquid refrigerant tube 41 flows toward the outdoor unit 1.
The operation mode of the indoor units 2 may be switched into any one of the cooling mode and the heating mode according to opening and closing operations of the high-pressure valve 31 and the low-pressure valve 32. For example, when the high-pressure valve 31 is closed and the low-pressure valve 32 is opened like the first indoor unit 21, the first indoor unit 21 is operated in the cooling mode. On the other hand, when the low-pressure valve 32 is closed and the high-pressure valve 31 is opened like the second indoor unit 22, the second indoor unit 22 is operated in the heating mode. That is, any one of the indoor units 2 may be operated in the cooling mode or the heating mode according to opening and closing operations of the high-pressure valve 31 and the low-pressure valve 32 of the corresponding indoor unit 2.
Hereinafter, the refrigerant flows of the indoor units and the distributor during the switching the operation mode of the indoor units in the refrigerant system according to the first embodiment will be described in detail with reference to accompanying drawings.
Fig. 2 is a view of a refrigerant flow in a case where an indoor unit of the refrigerant system is operated in a cooling mode according to the first embodiment. Fig. 3 is a view of a refrigerant flow in a case where the indoor unit of the refrigerant system is switched from the cooling mode or a stop mode to a heating mode according to the first embodiment. Fig. 4 is a view of a refrigerant flow in a case where the indoor unit of the refrigerant system is operated in a heating mode according to the first embodiment.
Referring to Figs. 2 to 4, in a case where the indoor unit 2 is operated in the cooling mode, like the first indoor unit 2 of Fig. 2, the refrigerant of the low-pressure tube 43 passes through the indoor unit 2 and then is introduced into the low-pressure tube 43 through the low-pressure branch tube 47. That is, when the indoor unit 2 is operated in the heating mode, the indoor unit 2 has the same refrigerant flow as the distributor 3 as shown in Fig. 2.
A case in which the indoor unit 2 should be switched from the cooling mode to the heating mode may occur during the operation of the refrigerant system. Also, in a state where the operation of the indoor unit 2 is stopped, the heating operation may start. In this case, a balancing process is performed to minimize impact and noise generated when the indoor unit 2 is switched to the heating mode. The balancing process represents a process in which the indoor unit tube 44 has the same pressure as the high-pressure branch tube 45.
In further detail, in a state where the operation of the indoor unit 2 is stopped or the indoor unit 2 is operated in the cooling mode, the high-pressure valve 31 and the high-pressure bypass valve 33 are maintained in the closed state. Thus, with respect to the high-pressure valve 31 and the high-pressure bypass valve 33, the inside of the refrigerant tube corresponding to a high-pressure tube side becomes a high-pressure state, and the inside of the refrigerant tube corresponding to an indoor unit tube side becomes a relatively low pressure state.
In a case where the indoor unit 2 is operated or switched in the heating mode, the high-pressure bypass valve 33 is opened first before the high-pressure valve is opened. That is, the balancing process is performed. At this time, when the balancing process is performed, the indoor expansion part 24, the high-pressure valve 31, and the low-pressure valve 32 are maintained in closed states, and the high-pressure bypass valve 33 is maintained in an opened state.
Thus, the refrigerant of the high-pressure tube 42 is introduced into the indoor unit tube 44 through the high-pressure bypass tube 46 due to a pressure difference between the high-pressure branch tube 45 and the indoor unit tube 44. When the balancing process is performed, a refrigerant flow between the indoor unit 2 and the distributor 3 is illustrated in Fig. 3. At this time, since the high-pressure bypass valve 33 has a capacity less than that of the high-pressure valve 31, the refrigerant of the high-pressure tube 42 may be more slowly introduced into the indoor tube 44 in the state where the high-pressure bypass valve 33 is opened when compared to the state in which the high-pressure valve 31 is opened. Thus, when the operation of the indoor unit 2 is switched, the impact and noise generated when the refrigerants having the pressure difference are mixed may be minimized.
Such the refrigerant flow occurs until the high-pressure branch tube 45 has the same pressure as the indoor unit tube 44. That is, through the balancing process, an internal pressure of the high-pressure branch tube 45 becomes gradually equal to that of the indoor unit tube 44.
When the balancing process is finished, i.e., when the internal pressure of the high-pressure branch 45 is equal or similar to that of the indoor unit tube 44, the indoor expansion part 24 and the high-pressure valve 31 are opened and the high-pressure bypass valve 33 is closed. Thus, the refrigerant of the high-pressure tube 42 passes through the indoor heat exchanger 23 to continuously flow toward the low-pressure tube 43. That is, the indoor unit 2 is operated in the heating mode. At this time, a refrigerant flow between the indoor unit 2 and the distributor 3 is illustrated in Fig. 4.
When the indoor expansion part 24 and the high-pressure valve 31 are fully opened, the refrigerant passes through the indoor expansion part 24 and the high-pressure valve 31 without changing a phase thereof. Also, the low-pressure valve 32 is maintained in the closed state.
Hereinafter, a process of switching an operation mode of the indoor unit of the refrigerant system according to the first embodiment will be described in detail with reference to accompanying drawings.
Fig. 5 is a block diagram of the refrigerant system according to the first embodiment, and Fig. 6 is a flowchart illustrating a process in which the refrigerant system is switched into the heating mode according to the first embodiment.
Referring to Fig. 5, the refrigerant system includes an input part 51 through which various input signals for switching the operation mode of the refrigerant system by a user are inputted and a control part 55 for controlling operations of the indoor expansion part 24, the high-pressure valve 31, the low-pressure valve 32, and the high-pressure bypass valve 33 according to the control signals transmitted from the input part 51. The input part 51, the control part 55, the indoor expansion part 24, the high-pressure valve 31, the low-pressure valve 32, and the high-pressure bypass valve 33 are electrically connected to receive and transmit the control signals from/to each other.
Referring to Fig. 6, during the operation of the refrigerant system, the indoor unit 2 may be switched from the stop mode or the cooling mode to the heating mode. In this case, in operation S11, a signal for switching the operation mode of the indoor unit 2 may be inputted into the input part 51 by the user.
When the signal for switching the operation mode of the indoor unit 2 to the heating mode is inputted, the indoor expansion part 24, the high-pressure valve 31, and the low-pressure valve 32 are closed and the high-pressure bypass valve 33 is opened in operation S12. That is, the balancing process is performed.
When a reference time elapses in operation S13 after the balance process starts, the high-pressure bypass valve and the low-pressure valve 32 are closed and the indoor expansion part 24 and the high-pressure valve 31 are opened in operation S14. That is, the indoor unit 2 is operated in the heating mode.
According to the refrigerant system, the impact and noise that may be generated when the operation mode of the indoor unit 2 is switched from the stop mode or the cooling mode to the heating mode may be minimized. In further detail, when the indoor unit 2 is operated in the stop mode or the cooling mode, the high-pressure valve 31 and the high-pressure bypass valve 33 are maintained in the closed state. Thus, with respect to the high-pressure valve 31 and the high-pressure bypass valve 33, the refrigerant tube corresponding to the high-pressure tube side and the refrigerant tube corresponding to the indoor unit tube side have the pressure difference therebetween.
When the indoor unit 2 is switched to the heating mode, the balancing process is performed before the high-pressure valve 31 is opened. That is, the high-pressure bypass valve 33 is opened first before the high-pressure valve 31 is opened to balance a pressure between the refrigerant tube corresponding to the high-pressure tube side and the refrigerant tube corresponding to the indoor unit tube side. Thus, when compared to a case in which the high-pressure valve 31 is opened, the refrigerant of the high-pressure tube 42 may be more slowly introduced into the indoor unit tube 44. As a result, the impact and noise generated when the refrigerant of the high-pressure tube 42 and the refrigerant of the indoor unit tube 44 are suddenly mixed with each other may be minimized.
The reference time may be previously set to an average time for balancing the pressure between the refrigerant tube corresponding to the high-pressure tube side and the refrigerant tube corresponding to the indoor unit tube side with respect to the high-pressure valve 31 and the high-pressure bypass valve 33.
Hereinafter, a process in which a refrigerant system is switched into a heating mode according to a second embodiment will be described in detail with reference to accompanying drawings. In this embodiment is different from the first embodiment in that a balancing process is finished according to a temperature of an indoor unit tube.
Fig. 7 is a block diagram of a refrigerant system according to a second embodiment, and Fig. 8 is a flowchart illustrating a process in which the refrigerant system is switched into a heating mode according to the second embodiment.
Referring to Fig. 7, a refrigerant system further includes an input part 61 through which various input signals for switching an operation mode of the refrigerant system by a user are inputted, a tube temperature sensor 62 for detecting a temperature of an indoor unit tube 44, and a control part controlling operations of an indoor expansion part 24, a high-pressure valve 31, a low-pressure valve 32, and a high-pressure bypass valve 33 according to the control signals transmitted from the input part 61 and the tube temperature sensor 62. The input part 61, the tube temperature sensor 62, the control part, the indoor expansion part 24, the high-pressure valve 31, the low-pressure valve 32, and the high-pressure bypass valve 33 are electrically connected to receive and transmit the control signals from/to each other.
Referring to Fig. 8, during the operation of the refrigerant system, an indoor unit 2 may be switched from a stop mode or a cooling mode to a heating mode. In this case, in operation S21, a signal for switching the operation mode of the indoor unit 2 may be inputted into the input part 61 by a user.
When the signal for switching the operation mode of the indoor unit 2 to the heating mode is inputted, the indoor expansion part 24, the high-pressure valve 31, and the low-pressure valve 32 are closed and the high-pressure bypass valve 33 is opened in operation S22. That is, the balancing process is performed.
In operation S23, after the balancing process is performed, the temperature of the indoor unit tube 44 is detected through the tube temperature sensor 62. When the temperature of the indoor unit tube 44 is less than a reference temperature in operation S24, the temperature of the indoor unit tube 44 is detected again in operation S23.
However, when the temperature of the indoor unit tube 44 is over the reference temperature in operation S24, the high-pressure bypass valve 33 and the low-pressure valve 32 are closed and the indoor expansion part 24 and the high-pressure valve 31 are opened in operation S25. That is, the indoor unit 2 is operated in the heating mode.
Here, the reference temperature may be previously set to a temperature valve representing that a pressure between the refrigerant tube corresponding to a high-pressure tube side and the refrigerant tube corresponding to an indoor unit tube side is balanced with respect to the high-pressure valve 31 and the high-pressure bypass valve 33. For example, the reference temperature may be set to a temperature of the high-pressure tube 42. This is done because the refrigerant of the high-pressure tube 42 should be introduced into the indoor unit tube 44 and mixed with the refrigerant of the indoor unit tube 44 to balance a pressure between the refrigerant tube corresponding to the high-pressure tube side and the refrigerant tube corresponding to the indoor unit tube side.
Hereinafter, a process in which a refrigerant system is switched into a heating mode according to a third embodiment will be described in detail with reference to accompanying drawings. In this embodiment is different from the first embodiment in that a balancing process is finished according to a temperature of an indoor unit tube.
Fig. 9 is a block diagram of a refrigerant system according to a third embodiment, and Fig. 10 is a flowchart illustrating a process in which the refrigerant system is switched into a heating mode according to the third embodiment.
Referring to Fig. 9, a refrigerant system further includes an input part 61 through which various input signals for switching an operation mode of the refrigerant system by a user are inputted, an indoor temperature sensor 72 for detecting an indoor room, a tube temperature sensor 73 for detecting a temperature of an indoor unit tube 44, and a control part 75 controlling operations of an indoor expansion part 24, a high-pressure valve 31, a low-pressure valve 32, and a high-pressure bypass valve 33 according to the control signals transmitted from the input part 71 and the tube temperature sensor 73. The input part 71, the indoor temperature sensor 72, the tube temperature sensor 73, the control part 75, the indoor expansion part 24, the high-pressure valve 31, the low-pressure valve 32, and the high-pressure bypass valve 33 are electrically connected to receive and transmit the control signals from/to each other.
Referring to Fig. 10, during the operation of the refrigerant system, an indoor unit 2 may be switched from a stop mode or a cooling mode to a heating mode. In this case, a signal for switching the operation mode of the indoor unit 2 may be inputted into the input part 71 by a user.
When the signal for switching the operation mode of the indoor unit 2 to the heating mode is inputted in operation S31, the indoor expansion part 24, the high-pressure valve 31, and the low-pressure valve 32 are closed and the high-pressure bypass valve 33 is opened in operation S32. That is, the balancing process is performed.
In operation S33, after the balancing process is performed, the indoor temperature is detected through the indoor temperature sensor 72 and the temperature of the indoor unit tube 44 is detected through the tube temperature sensor 73. When a difference between the temperature of the indoor unit tube 44 and the indoor temperature is less than a reference temperature, that is, the indoor unit tube 44 has a temperature greater by the reference temperature than the indoor temperature or different from the reference temperature in operation s34, the indoor temperature and the temperature of the indoor unit tube 44 are detected again in operation S33.
However, when the difference between the temperature of the indoor unit tube 44 and the indoor temperature is over the reference temperature, that is, the temperature of the indoor unit tube 44 is greater by the reference temperature than the indoor temperature in operation S34, the high-pressure bypass valve 33 and the low-pressure valve 32 are closed and the indoor expansion part 24 and the high-pressure valve 31 are opened in operation S25. That is, the indoor unit 2 is operated in the heating mode.
Here, the reference temperature may be previously set to a temperature valve representing that a pressure between the refrigerant tube corresponding to a high-pressure tube side and the refrigerant tube corresponding to an indoor unit tube side is balanced with respect to the high-pressure valve 31 and the high-pressure bypass valve 33. For example, the reference temperature may be set to the difference value between the temperature of the high-pressure tube 42 and the indoor temperature.
In the refrigerator according to the embodiments, since the hinge shaft having the screw thread is provided and the adjustment member movably along the hinge shaft and coupled to the hinge shaft is provided, the door may be easily supported. Thus, industrial applicability may be significantly improved.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope of the invention. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the invention, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims

A refrigerant system comprising:
an outdoor unit (1) comprising an outdoor heat exchanger (11) in which a refrigerant is heat-exchanged with outdoor air and a compressor compressing the refrigerant;

a plurality of indoor units (2) comprising a plurality of indoor heat exchangers (23) in which the refrigerant is heat-exchanged with indoor air, respectively;

a high-pressure tube (42) guiding the refrigerant discharged from the compressor to the indoor heat exchangers;

a low-pressure tube (43) guiding the refrigerant evaporated from at least one of the indoor heat exchangers to the compressor;

a high-pressure branch tube (45) branched from the high-pressure tube to guide the refrigerant of the high-pressure tube to any one of the indoor heat exchangers;

a low-pressure branch tube (47) branched from the low-pressure tube to guide the refrigerant of any one of the indoor heat exchangers to the low-pressure tube;

a low-pressure valve (32) disposed in the low-pressure branch tube to selectively interrupt a refrigerant flow within the low-pressure branch tube;

a liquid refrigerant tube (41) connecting the outdoor heat exchanger to the indoor heat exchangers to flow the refrigerant condensed in at least one of the outdoor heat exchanger and the indoor heat exchangers;

an indoor unit tube (44) connecting any one of the indoor heat exchangers with both the high-pressure branch tube (45) and the low-pressure branch tube (47);

a high-pressure valve (31) disposed in the high-pressure branch tube to selectively interrupt a refrigerant flow within the high-pressure branch tube;

a high-pressure bypass tube (46) provided with one end disposed at the high-pressure branch tube between the high-pressure tube and the high-pressure valve and the other end disposed at the indoor unit tube;

a high-pressure bypass valve (33) installed at the high-pressure bypass tube to guide the refrigerant of the high-pressure branch tube to flow into the indoor unit tube by bypassing the high-pressure valve;

a tube temperature sensor (73) to detect a temperature of the indoor unit tube;

an indoor temperature sensor (72) to detect an indoor temperature;

an indoor expansion part (24) for expanding the refrigerant flowing into the heat exchanger; and

a controller (75) configured to control the operation of the refrigerant system, when an indoor unit may be switched from a stop mode or a cooling mode to a heating mode,

wherein when switching the operation mode of the indoor unit to the heating mode, a balancing process is performed wherein the indoor expansion part, the high-pressure valve, and the low-pressure valve are closed and the high-pressure bypass valve is opened, and

wherein when the difference of the temperature of the indoor unit tube and the indoor temperature is lower than a reference temperature, the balancing process is continued, and

when the difference of the temperature of the indoor unit tube and the indoor temperature is higher than the reference temperature, the high-pressure bypass valve and the low-pressure valve are closed and the indoor expansion part and the high-pressure valve are opened and the indoor unit is operated in the heating mode.
The refrigerant system according to claim 1, wherein the refrigerant from the high-pressure branch tube flows into the indoor unit tube through the high-pressure bypass tube when an operation mode of the indoor unit is switched to a heating mode.
The refrigerant system according to claim 1, wherein the high-pressure bypass valve has a capacity less than that of the high-pressure valve.
The refrigerant system according to claim 1, wherein the high-pressure bypass valve is opened when an operation mode of the indoor unit is switched to a heating mode.
The refrigerant system according to claim 1, wherein the high-pressure bypass valve is opened and then the high-pressure valve is opened when an operation mode of the indoor unit is switched to a heating mode.
The refrigerant system according to claim 1, wherein the high-pressure bypass valve is closed when the high-pressure valve is opened.