U.S. patent application number 15/329847 was filed with the patent office on 2018-01-18 for multi-online system.
The applicant listed for this patent is GD MIDEA HEATING & VENTILATING EQUIPMENT CO., LTD., MIDEA GROUP CO., LTD.. Invention is credited to Junwei CHEN, Bin LUO.
Application Number | 20180017271 15/329847 |
Document ID | / |
Family ID | 53588336 |
Filed Date | 2018-01-18 |
United States Patent
Application |
20180017271 |
Kind Code |
A1 |
LUO; Bin ; et al. |
January 18, 2018 |
MULTI-ONLINE SYSTEM
Abstract
A multi-split system includes an outdoor unit, a distribution
device, and a plurality of indoor units. The distribution device
includes a gas-liquid separator, a first heat exchange assembly, a
first electronic expansion valve, a second heat exchange assembly,
a second electronic expansion valve, a third electronic expansion
valve connected in parallel with the second electronic expansion
valve. When the flow rate of the refrigerant passing through the
first electronic expansion valve is greater than a first preset
value, the distribution device is configured to calculate a value
of superheat degree according to the outlet temperature of the
indoor heat exchanger of each cooling indoor unit and the
temperature of the refrigerant flowing into the second heat
exchange assembly, and to perform a PI control over the second
electronic expansion valve and the third electronic expansion valve
according to the value of superheat degree.
Inventors: |
LUO; Bin; (Foshan, CN)
; CHEN; Junwei; (Foshan, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GD MIDEA HEATING & VENTILATING EQUIPMENT CO., LTD.
MIDEA GROUP CO., LTD. |
Foshan
Foshan |
|
CN
CN |
|
|
Family ID: |
53588336 |
Appl. No.: |
15/329847 |
Filed: |
December 22, 2015 |
PCT Filed: |
December 22, 2015 |
PCT NO: |
PCT/CN2015/098289 |
371 Date: |
January 27, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2313/029 20130101;
F25B 2700/191 20130101; F25B 41/04 20130101; F25B 41/062 20130101;
F25B 49/02 20130101; F25B 2700/2103 20130101; F24F 2140/20
20180101; F24F 1/0003 20130101; F25B 40/00 20130101; F24F 11/89
20180101; F24F 2110/00 20180101; F25B 2313/0231 20130101; F25B
2400/23 20130101; F25B 2600/2509 20130101; F24F 3/06 20130101; F25B
2313/0233 20130101; F25B 13/00 20130101; F25B 2313/0314 20130101;
F24F 11/30 20180101; F25B 2341/0661 20130101; F25B 2700/13
20130101 |
International
Class: |
F24F 3/06 20060101
F24F003/06; F24F 11/00 20060101 F24F011/00; F24F 1/00 20110101
F24F001/00; F24F 11/02 20060101 F24F011/02; F25B 49/02 20060101
F25B049/02; F25B 41/06 20060101 F25B041/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2015 |
CN |
201510151379.0 |
Claims
1. A multi-split system, comprising an outdoor unit, a distribution
device, and a plurality of indoor units, wherein the distribution
device comprises a gas-liquid separator, a first heat exchange
assembly, a first electronic expansion valve, a second heat
exchange assembly, a second electronic expansion valve, a third
electronic expansion valve connected in parallel with the second
electronic expansion valve, in which the distribution device is
configured to acquire a flow rate of a refrigerant passing through
the first electronic expansion valve, and when the flow rate of the
refrigerant passing through the first electronic expansion valve is
greater than a first preset value, the distribution device is
configured to acquire an outlet temperature of an indoor heat
exchanger of each cooling indoor unit of the plurality of indoor
units and a temperature of the refrigerant flowing into the second
heat exchange assembly respectively, and to calculate a value of
superheat degree according to the outlet temperature of the indoor
heat exchanger of each cooling indoor unit and the temperature of
the refrigerant flowing into the second heat exchange assembly, and
to perform a PI control over the second electronic expansion valve
and the third electronic expansion valve according to the value of
superheat degree.
2. The multi-split system according to claim 1, wherein when the
flow rate of the refrigerant passing through the first electronic
expansion valve is less than a second preset value, the
distribution device is further configured to acquire a temperature
of the refrigerant discharged to the outdoor unit from the first
heat exchange assembly, and to calculate the value of superheat
degree according to the temperature of the refrigerant flowing into
the second heat exchange assembly and the temperature of the
refrigerant discharged to the outdoor unit from the first heat
exchange assembly, in which the second preset value is less than
the first preset value.
3. The multi-split system according to claim 1, wherein the
distribution device calculates the value of superheat degree
according to following formula: .DELTA.SH=T2b Average-i Tm2, in
which T2bAverage is an average value of the outlet temperature of
the indoor heat exchanger of each cooling indoor unit, and Tm2 is
the temperature of the refrigerant flowing into the second heat
exchange assembly.
4. The multi-split system according to claim 2, wherein the
distribution device calculates the value of superheat degree
according to following formula: .DELTA.SH=Tm3-Tm2, in which Tm3 is
the temperature of the refrigerant discharged to the outdoor unit
from the first heat exchange assembly, and Tm2 is the temperature
of the refrigerant flowing into the second heat exchange
assembly.
5. The multi-split system according to claim 1, wherein the
multi-split system works under a main cooling mode.
6. The multi-split system according to claim 1, wherein the outlet
temperature of the indoor heat exchanger of each cooling indoor
unit is detected by a temperature sensor provided at an outlet of
the indoor heat exchanger of each cooling indoor unit, and the
temperature of the refrigerant flowing into the second heat
exchange assembly is detected by a temperature sensor provided at
an outlet of the second electronic expansion valve.
7. The multi-split system according to claim 2, wherein the
multi-split system works under a main cooling mode.
8. The multi-split system according to claim 3, wherein the
multi-split system works under a main cooling mode.
9. The multi-split system according to claim 4, wherein the
multi-split system works under a main cooling mode.
Description
FIELD
[0001] The present disclosure relates to air conditioning
technology field, and more particularly, to a multi-split
system.
BACKGROUND
[0002] With the continuous development of air conditioning
technology and strengthening of people's environment protection
consciousness, a heat recovery multi-split system is more and more
popular in the market. A two-pipe heat recovery multi-split system
is one of the dominant heat recovery multi-split systems on the
current market, in which the two-pipe heat recovery multi-split
system is able to realize a simultaneous cooling and heating. In
order to make both of the cooling and heating indoor units achieve
a good efficiency, a superheat degree of the distribution device is
a key control point, and this needs a temperature sensor to collect
the temperature values of the front and back of the heat exchange
assembly in the distribution device to calculate the superheat
degree.
[0003] In the related art, under a main cooling mode, a direct
function of a second electronic expansion valve is to provide a
heating indoor unit with a required subcooling degree of the
refrigerant, and this usually needs to calculate a superheat degree
of the distribution device according to the temperature values of
the front and back of itself, and then to adjust the opening of the
second electronic expansion valve according to a given target value
to meet the requirement for the superheat degree. In addition, such
a control method has a limited and insufficient adjustment range,
and needs to be improved.
SUMMARY
[0004] The present disclosure aims to solve one of the technical
problems at least to some extent. Therefore, an objective of the
present disclosure is to provide a multi-split system. Thus, a
superheat degree of a distribution device may be accurately
calculated, and an accurate distribution of a refrigerant in a
system may be realized such that an optimal effect of simultaneous
heating and cooling of the multi-split system may be achieved.
[0005] To achieve the above objective, a multi-split system is
provided in embodiments of the present disclosure, including an
outdoor unit, a distribution device, and a plurality of indoor
units. The distribution device includes a gas-liquid separator, a
first heat exchange assembly, a first electronic expansion valve, a
second heat exchange assembly, a second electronic expansion valve,
a third electronic expansion valve connected in parallel with the
second electronic expansion valve. The distribution device is
configured to acquire a flow rate of a refrigerant passing through
the first electronic expansion valve. When the flow rate of the
refrigerant passing through the first electronic expansion valve is
greater than a first preset value, the distribution device is
configured to acquire an outlet temperature of an indoor heat
exchanger of each cooling indoor unit of the plurality of indoor
units and a temperature of the refrigerant flowing into the second
heat exchange assembly respectively, and to calculate a value of
superheat degree according to the outlet temperature of the indoor
heat exchanger of each cooling indoor unit and the temperature of
the refrigerant flowing into the second heat exchange assembly, and
to perform a PI control over the second electronic expansion valve
and the third electronic expansion valve according to the value of
superheat degree.
[0006] By the multi-split system according to embodiments of the
present disclosure, the distribution device acquires a flow rate of
the refrigerant passing through the first electronic expansion
valve first, and when the flow rate of the refrigerant passing
through the first electronic expansion valve is greater than a
first preset value, the distribution device acquires an outlet
temperature of an indoor heat exchanger of each cooling indoor unit
of the plurality of indoor units and a temperature of the
refrigerant flowing into the second heat exchange assembly
respectively, and calculates a value of superheat degree of the
distribution device according to the an outlet temperature of an
indoor heat exchanger of each cooling indoor unit and the
temperature of the refrigerant flowing into the second heat
exchange assembly, and performs a PI control over the second
electronic expansion valve and the third electronic expansion valve
according to the calculated value of superheat degree. Therefore,
the multi-split system according to embodiments of the present
disclosure accurately acquires the value of superheat degree of the
distribution device by determining the flow rate of the refrigerant
passing through the first electronic expansion valve, which avoids
an inaccuracy of an acquired value of superheat degree caused by an
inaccuracy of the measured temperature in case of a large flow rate
or a small flow rate, and thus a failure of real reflection of a
control of superheat degree may be prevented such that an accurate
distribution of the refrigerant in a system may be realized, and an
optimal effect of simultaneous heating and cooling of the
multi-split system may be achieved.
[0007] According to an embodiment of the present disclosure, when
the flow rate of the refrigerant passing through the first
electronic expansion valve is less than a second preset value, the
distribution device is further configured to acquire a temperature
of the refrigerant discharged to the outdoor unit from the first
heat exchange assembly, and to calculate the value of superheat
degree according to the temperature of the refrigerant flowing into
the second heat exchange assembly and the temperature of the
refrigerant discharged to the outdoor unit from the first heat
exchange assembly, in which the second preset value is less than
the first preset value.
[0008] According to an embodiment of the present disclosure, the
distribution device calculates the value of superheat degree
according to following formula:
.DELTA.SH=T2bAverage-Tm2,
[0009] in which T2bAverage is an average value of the outlet
temperature of the indoor heat exchanger of each cooling indoor
unit, and Tm2 is the temperature of the refrigerant flowing into
the second heat exchange assembly.
[0010] According to another embodiment of the present disclosure,
the distribution device calculates the value of superheat degree
according to following formula:
.DELTA.SH=Tm3-Tm2,
[0011] in which Tm3 is the temperature of the refrigerant
discharged to the outdoor unit from the first heat exchange
assembly, and Tm2 is the temperature of the refrigerant flowing
into the second heat exchange assembly.
[0012] In embodiments of the present disclosure, the multi-split
system works under a main cooling mode.
[0013] According to an embodiment of the present disclosure, the
outlet temperature of the indoor heat exchanger of each cooling
indoor unit is detected by a temperature sensor provided at an
outlet of the indoor heat exchanger of each cooling indoor unit,
and the temperature of the refrigerant flowing into the second heat
exchange assembly is detected by a temperature sensor provided at
an outlet of the second electronic expansion valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic view of a multi-split system according
to an embodiment of the present disclosure;
[0015] FIG. 2 is schematic view of a multi-split system operates
under a pure heating mode according to an embodiment of the present
disclosure;
[0016] FIG. 3 is schematic view of a multi-split system operates
under a main heating mode according to an embodiment of the present
disclosure;
[0017] FIG. 4 is a schematic view of a multi-split system operates
under a pure cooling mode according to an embodiment of the present
disclosure;
[0018] FIG. 5 is a schematic view of a multi-split system operates
under a main cooling mode according to an embodiment of the present
disclosure; and
[0019] FIG. 6 is a communication network diagram of a multi-split
system according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0020] Embodiments of the present disclosure will be described in
detail in the following descriptions, examples of which are shown
in the accompanying drawings, in which the same or similar elements
and elements having same or similar functions are denoted by like
reference numerals throughout the descriptions. The embodiments
described herein with reference to the accompanying drawings are
explanatory and illustrative, which are used to generally
understand the present disclosure. The embodiments shall not be
construed to limit the present disclosure.
[0021] Next, a multi-split system according to embodiments of the
present disclosure will be described by referring to the
accompanying drawings.
[0022] As shown in FIG. 1 to FIG. 5, the multi-split system
according to embodiments of the present disclosure includes: an
outdoor unit 10, a plurality of indoor units, such as four indoor
units 21, 22, 23, 24 and a distribution device 30.
[0023] The outdoor unit 10 includes a compressor 101, a four-way
valve 102, an outdoor heat exchanger 103, an outdoor gas-liquid
separator 104, an oil separator 105, a first electromagnetic valve
106, a capillary 107, four one-way valves 108A, 108B, 108C, 108D, a
first interface 109 and a second interface 110. The compressor 101
has an exhaust port and a gas returning port, and the four-way
valve 102 has a first valve port to a fourth valve port, in which
the first valve port is communicated with one of the second valve
port and the third valve port, and the fourth valve port is
communicated with the other one of the second valve port and the
third valve port, and the first valve port is communicated with the
exhaust port of the compressor 101 through the oil separator 105,
and the fourth valve port is communicated with the gas returning
port of the compressor 101 through the outdoor gas-liquid separator
104, and the one-way valve 108A is connected in series between the
second valve port and the first interface 109, and the third valve
port is connected to a first end of the outdoor heat exchanger
103.
[0024] The distribution device 30 includes a gas-liquid separator
301, a plurality of first controlling valves (such as four first
controlling valves 302A, 302B, 302C, 302D), a plurality of second
controlling valves (such as four second controlling valves 303A,
303B, 303C, 303D), a first electronic expansion valve 304A, a
second electronic expansion valve 304B, a third electronic
expansion valve 304C connected in parallel with the second
electronic expansion valve 304B, four first one-way valves 305A,
305B, 305C, 305D, four second one-way valves 306A, 306B, 306C,
306D, a first heat exchange assembly 307A and a second heat
exchange assembly 307B. The gas-liquid separator 301 has an inlet,
a gas outlet and a liquid outlet, the inlet is connected to a
second end of the outdoor heat exchanger 103 through a
high-pressure stop valve 40 and the one-way valve 108B, the gas
outlet is connected to the four second controlling valves 303A,
303B, 303C, 303D respectively; the four first controlling valves
302A, 302B, 302C, 302D are connected to the first interface 109
through the low-pressure stop valve 50 respectively. The first heat
exchange assembly 307A and the second heat exchange assembly 307B
may be plate heat exchangers, and may also be double-pipe heat
exchangers.
[0025] As shown in FIG. 1 to FIG. 5, the first end of the one-way
valve 108A is connected between the one-way valve 108B and the
second interface 110 through the one-way valve 108C, and the second
end of the one-way valve 108A is connected between the one-way
valve 108B and the outdoor heat exchanger 103 through the one-way
valve 108D.
[0026] The first heat exchange assembly 307A and the second heat
exchange assembly 307B each have a first heat exchange flow path
and a second heat exchange flow path, and the liquid outlet of the
gas-liquid separator 301 is connected to the first heat exchange
flow path of the first heat exchange assembly 307A, and the first
heat exchange flow path of the first heat exchange assembly 307A is
connected to the first electronic expansion valve 304A, and the
second heat exchange flow path of the first heat exchange assembly
307A is connected to the second heat exchange flow path of the
second heat exchange assembly 307B and the four first controlling
valves 302A, 302B, 302C, 302D respectively.
[0027] As shown in FIG. 1 to FIG. 5, each indoor unit includes an
indoor heat exchanger and a throttling element. The indoor unit 21
includes an indoor heat exchanger 211 and a throttling element 212,
and the indoor unit 22 includes an indoor heat exchanger 221 and a
throttling element 222, and the indoor unit 23 includes an indoor
heat exchanger 231 and a throttling element 232, and the indoor
unit 24 includes an indoor heat exchanger 241 and a throttling
element 242. The first end of the indoor heat exchanger in each
indoor unit is connected to the corresponding throttling element,
the second end of the indoor heat exchanger in each indoor unit is
connected to the corresponding first controlling valve and second
controlling valve, and the throttling element in each indoor unit
is connected to the corresponding first one-way valve and the
second one-way valve, and the flow direction of the first one-way
valve is opposite to the flow direction of the second one-way
valve. Moreover, the four first one-way valves 305A, 305B, 305C,
305D are all connected to a first common flow path, and the four
second one-way valves 306A, 306B, 306C, 306D are all connected to a
second common flow path, and the first heat exchange flow path of
the second heat exchange assembly 307B is communicated with the
first common flow path and the second common flow path
respectively, and the first electronic expansion valve 304A is
connected to the first common flow path, and the second electronic
expansion valve 304B is connected to the second heat exchange flow
path of the second heat exchange assembly 307B and the second
common flow path respectively, and the first electronic expansion
valve 304A is further connected with the second electromagnetic
valve 308 in parallel.
[0028] In embodiments of the present disclosure, the distribution
device 30 is configured to acquire a flow rate of the refrigerant
passing through the first electronic expansion valve 304A, and when
the flow rate of the refrigerant passing through the first
electronic expansion valve 304A is greater than the first preset
value (i.e., a large flow rate), the distribution device 30 is
configured to acquire an outlet temperature of an indoor heat
exchanger of each cooling indoor unit in the plurality of indoor
units and the temperature of the refrigerant flowing into the
second heat exchange assembly respectively, and to calculate a
value of superheat degree according to the outlet temperature of
the indoor heat exchanger of each cooling indoor unit and the
temperature of the refrigerant flowing into the second heat
exchange assembly, and to perform a PI control over the second
electronic expansion valve and the third electronic expansion valve
according to the value of superheat degree.
[0029] According to an embodiment of the present disclosure, when
the flow rate of the refrigerant passing through the first
electronic expansion valve is less than the second preset value
(i.e., a small flow rate), the distribution device is further
configured to acquire a temperature of the refrigerant discharged
to the outdoor unit from the first heat exchange assembly, and to
calculate the value of superheat degree according to the
temperature of the refrigerant flowing into the second heat
exchange assembly and the temperature of the refrigerant discharged
to the outdoor unit from the first heat exchange assembly, in which
the second preset value is less than the first preset value.
[0030] When calculating the value of superheat degree in case of a
large flow rate, the distribution device calculates the value of
superheat degree according to following formula:
.DELTA.SH=T2bAverage-Tm2,
[0031] in which T2bAverage is an average value of the outlet
temperature of the indoor heat exchanger of each cooling indoor
unit, and Tm2 is the temperature of the refrigerant flowing into
the second heat exchange assembly. When calculating the value of
superheat degree in case of a small flow rate, the distribution
device calculates the value of superheat degree according to
following formula:
.DELTA.SH=Tm3-Tm2,
[0032] in which Tm3 is the temperature of the refrigerant
discharged to the outdoor unit from the first heat exchange
assembly, and Tm2 is the temperature of the refrigerant flowing
into the second heat exchange assembly.
[0033] Therefore, the multi-split system according to embodiments
of the present disclosure may accurately acquire the value of
superheat degree of the distribution device by determining the flow
rate of the refrigerant passing through the first electronic
expansion valve, which avoids an inaccuracy of the acquired value
of superheat degree caused by an inaccuracy of the measured
temperature in case of a large flow rate or a small flow rate, and
thus a failure of real reflection of the control of the superheat
degree is prevented such that an accurate distribution of the
refrigerant in the system may be realized.
[0034] According to an embodiment of the present disclosure, as
shown in FIG. 1 to FIG. 5, a pressure sensor 309A and a pressure
sensor 309B are provided at two ends of the first electronic
expansion valve 304A and the second electromagnetic valve 308 in
parallel connection respectively, and a temperature sensor 310A and
a temperature sensor 310B are provided at two ends of the first
heat exchange flow path of the second heat exchange assembly 307B
respectively. In addition, a pressure sensor 309C is provided at
one end of the second heat exchange flow path of the first heat
exchange assembly 307A.
[0035] Moreover, the outlet temperature of the indoor heat
exchanger of each cooling indoor unit is detected by a temperature
sensor provided at an outlet of the indoor heat exchanger of each
cooling indoor unit, and the temperature of the refrigerant flowing
into the second heat exchange assembly is detected by a temperature
sensor provided at an outlet of the second electronic expansion
valve.
[0036] In embodiments of the present disclosure, the multi-split
system controls a superheat degree when working under a main
cooling mode. It should be noted that, the operation mode of the
multi-split system further includes a pure cooling mode, a pure
heating mode and a main heating mode.
[0037] Next, flow directions of refrigerants when the multi-split
system works under a pure heating mode, a main heating mode, a pure
cooling mode and a main cooling mode will be described respectively
by referring to FIG. 2 to FIG. 5.
[0038] As shown in FIG. 2, when the outdoor unit 10 determines that
the multi-split system works under a pure heating mode, the four
indoor units perform heating work. The flow direction of a
refrigerant will be described as follows: a high-pressure gas flows
into the four-way valve 102 through the oil separator 105 from the
exhaust port of the compressor 101, then flows into the gas-liquid
separator 301 via the one-way valve 108C, the second interface 110
and the high-pressure stop valve 40, and the high-pressure gas
flows into the corresponding four indoor heat exchangers via the
four second controlling valves 303A, 303B, 303C, 303D respectively
from the gas outlet of the gas-liquid separator 301, and then turns
into a high-pressure liquid; then, the four-way high-pressure
liquid flows into the first heat exchange flow path of the second
heat exchange assembly 307B via the corresponding throttling
elements and the four first one-way valves 305A, 305B, 305C, 305D,
and turns into a low-pressure gas-liquid two-phase refrigerant via
the second electronic expansion valve 304B; the low-pressure
gas-liquid two-phase refrigerant flows back to the outdoor unit 10
via the second heat exchange flow path of the second heat exchange
assembly 307B and the second heat exchange flow path of the first
heat exchange assembly 307A, that is, the low-pressure gas-liquid
two-phase refrigerant turns into a low-pressure gas after flowing
back to the outdoor heat exchanger 103 via the low-pressure stop
valve 50, the first interface 109 and the one-way valve 108D, and
the low-pressure gas flows back to the gas returning port of the
compressor 101 via the four-way valve 102 and the outdoor
gas-liquid separator 104.
[0039] As shown in FIG. 3, when the outdoor unit 10 determines that
the multi-split system works under a main heating mode, three of
the four indoor units perform heating work, and one indoor unit
performs cooling work. The flow direction of a refrigerant for
heating will be described as follows: a high-pressure gas flows
into the four-way valve 102 through the oil separator 105 from the
exhaust port of the compressor 101, then flows into the gas-liquid
separator 301 via the one-way valve 108C, the second interface 110
and the high-pressure stop valve 40, and the high-pressure gas
flows into the indoor heat exchangers in the corresponding three
heating indoor units via the three second controlling valves 303A,
303B, 303C respectively from the gas outlet of the gas-liquid
separator 301, then turns into a high-pressure liquid, and then the
three-way high-pressure liquid flows into the first heat exchange
flow path of the second heat exchange assembly 307B via the
corresponding throttling elements and the three first one-way
valves 305A, 305B, 305C, and turns into a low-pressure gas-liquid
two-phase refrigerant via the second electronic expansion valve
304B, and the low-pressure gas-liquid two-phase refrigerant flows
back to the outdoor unit 10 via the second heat exchange flow path
of the second heat exchange assembly 307B and the second heat
exchange flow path of the first heat exchange assembly 307A, that
is, the low-pressure gas-liquid two-phase refrigerant turns into a
low-pressure gas after flowing back to the outdoor heat exchanger
103 via the low-pressure stop valve 50, the first interface 109 and
the one-way valve 108D, and the low-pressure gas flows back to the
gas returning port of the compressor 101 via the four-way valve 102
and the outdoor gas-liquid separator 104. The flow direction of a
refrigerant for cooling will be described as follows: a part of the
high-pressure liquid flowing through the first heat exchange flow
path of the second heat exchange assembly 307B further turns into a
low-pressure gas-liquid two-phase refrigerant after flowing into
the throttling element 242 in the indoor unit 24 via the second
one-way valve 306D, then turns into a low-pressure gas via the
indoor heat exchanger 241 in the indoor unit 24; after flowing
through the first controlling valve 302D, the low-pressure gas
flows back to the outdoor unit 10 after being mixed with the
low-pressure gas-liquid two-phase refrigerant flowing through the
second heat exchange flow path of the second heat exchange assembly
307B and the second heat exchange flow path of the first heat
exchange assembly 307A.
[0040] As shown in FIG. 4, when the outdoor unit 10 determines that
the multi-split system works under a pure cooling mode, the four
indoor units perform cooling work. The flow direction of a
refrigerant will be described as follows: a high-pressure gas flows
into the four-way valve 102 through the oil separator 105 from the
exhaust port of the compressor 101, then turns into a high-pressure
liquid after flowing through the outdoor heat exchanger 103, and
the high-pressure liquid flows into the gas-liquid separator 301
via the one-way valve 108B, the second interface 110 and the
high-pressure stop valve 40, and the high-pressure liquid flows
into the first electronic expansion valve 304A and the second
electromagnetic valve 308 via the first heat exchange flow path of
the first heat exchange assembly 307A from the liquid outlet of the
gas-liquid separator 301, then flows into the four second one-way
valves 306A, 306B, 306C, 306D respectively via the first heat
exchange flow path of the second heat exchange assembly 307B, and
the four-way high-pressure liquid flowing through the four second
one-way valves 306A, 306B, 306C, 306D turns into a four-way
low-pressure gas-liquid two-phase refrigerant after correspondingly
flowing through the throttling elements in the four indoor units
respectively, and the four-way low-pressure gas-liquid two-phase
refrigerant turns into a four-way low-pressure gas after flowing
through the corresponding indoor heat exchangers respectively, and
then the low-pressure gas flows back to the outdoor unit 10
correspondingly via the four first controlling valves 302A, 302B,
302C, 302D, that is, the low-pressure gas flows back to the gas
returning port of the compressor 101 via the low-pressure stop
valve 50, the first interface 109, the one-way valve 108A and the
outdoor gas-liquid separator 104.
[0041] As shown in FIG. 5, when the outdoor unit 10 determines that
the multi-split system works under a main cooling mode, three of
the four indoor units perform cooling works and one indoor unit
performs heating work. The flow direction of a refrigerant for
cooling will be described as follows: a high-pressure gas flows
into the four-way valve 102 through the oil separator 105 from the
exhaust port of the compressor 101, then turns into a high-pressure
gas-liquid two-phase refrigerant after flowing through the outdoor
heat exchanger 103, and the high-pressure gas-liquid two-phase
refrigerant flows into the gas-liquid separator 301 via the one-way
valve 108B, the second interface 110 and the high-pressure stop
valve 40 to perform a gas-liquid separation, in which the
high-pressure liquid flows into the first electronic expansion
valve 304A and the second electromagnetic valve 308 via the first
heat exchange flow path of the first heat exchange assembly 307A
from the liquid outlet of the gas-liquid separator 301, then flows
into the three second one-way valves 306A, 306B, 306C via the first
heat exchange flow path of the second heat exchange assembly 307B
respectively, the three-way high-pressure liquid flowing through
the three second one-way valves 306A, 306B, 306C turns into a
three-way low-pressure gas-liquid two-phase refrigerant after
correspondingly flowing through throttling elements in the three
indoor units respectively, and the three-way low-pressure
gas-liquid two-phase refrigerant turns into three-way low-pressure
gas after flowing through the corresponding indoor heat exchangers
respectively, then flows back to the outdoor unit 10
correspondingly via the three first controlling valves 302A, 302B,
302C, that is, the low-pressure gas flows back to the gas returning
port of the compressor 101 via the low-pressure stop valve 50, the
first interface 109, the one-way valve 108A, and the outdoor
gas-liquid separator 104. The flow direction of a refrigerant for
heating will be described as follows: a high-pressure gas after the
gas-liquid separation through the gas-liquid separator 301 flows
into the indoor heat exchanger 241 in the indoor unit 24 via the
second controlling valve 303D from the gas outlet of the gas-liquid
separator 301, then turns into a high-pressure liquid; and after
flowing through the throttling element 242 in the indoor unit 24,
the high-pressure liquid joins the high-pressure liquid flowing
through the first heat exchange flow path of the second heat
exchange assembly 307B via the first one-way valve 305D.
[0042] In embodiments of the present disclosure, in order to
realize an automatic control of the pressure difference AP between
the front and back of the first electronic expansion valve 304A,
each indoor unit needs to send an operating parameter of the indoor
unit to the distribution device 30, in which the operating
parameter of each indoor unit includes: an operating mode of the
indoor unit (such as a cooling mode, a heating mode, etc.), a
superheat degree when the indoor unit serves as a cooling indoor
unit, an opening of the throttling element when the indoor unit
serves as a cooling indoor unit, a subcooling degree when the
indoor unit serves as a heating indoor unit, an opening of the
throttling element when the indoor unit serves as a heating indoor
unit, etc.
[0043] According to an embodiment of the present disclosure, as
shown in FIG. 6, the outdoor unit and the distribution device may
communicate with each other directly, and each indoor unit
communicates with the outdoor unit through the distribution device.
Each indoor unit is allocated with an address for convenience for
the communications between individual indoor units and
communications between each indoor unit and the distribution
device, for example, the first indoor unit is allocated with a
first address, and the second indoor unit is allocated with a
second address, , and the seventh indoor unit is allocated with a
seventh address. In addition, each indoor unit further includes a
wired controller, and each indoor unit further communicates with a
respective wired controller.
[0044] Further, according to a specific example of the present
disclosure, the outdoor controller in the outdoor unit communicates
with the control module in the distribution device, meanwhile, the
control module in the distribution device communicates with the
indoor controllers in each indoor unit. The outdoor controller in
the outdoor unit acquires temperature information of the outdoor
unit (such as a temperature of the environment in which the outdoor
unit is located, an exhausting temperature, a gas returning
temperature, a heat exchange temperature, etc.), pressure
information (such as an exhausting pressure, a gas returning
pressure, etc.) and operating modes of each indoor unit sent by a
plurality of indoor units and so on in real time to determine an
operating mode of the multi-split system (such as a pure heating
mode, a main heating mode, a pure cooling mode and a main cooling
mode), and sends the instruction indicating the operating mode of
the multi-split system to the distribution device. Meanwhile, the
outdoor controller in the outdoor unit further controls the
compressor and the outdoor fan, etc. to operate according to the
inner logic output instruction signal.
[0045] Specifically, after the multi-split system is turned on, the
outdoor controller in the outdoor unit acquires environment
temperature information, pressure information of the outdoor unit
and operating modes of each indoor unit to determine an operating
mode of the multi-split system. For example, when each indoor unit
operates under a cooling mode, the operating mode of the
multi-split system is a pure cooling mode; when each indoor unit
operates under a heating mode, the operating mode of the
multi-split system is a pure heating mode; when there are both
indoor units operating under a cooling mode and indoor units
operating under a heating mode in the plurality of indoor units,
the operating mode of the multi-split system is a simultaneous
cooling and heating mode, and the outdoor unit sends corresponding
mode instruction to the distribution device according to the
determined operating mode of the system. Meanwhile, the outdoor
unit controls the compressor and the outdoor fan, etc. to operate
according to the inner logic output instruction signal. The
distribution device controls each status parameter according to the
mode instruction given by the outdoor unit.
[0046] In embodiments of the present disclosure, first, among the
plurality of indoor units, a cooling indoor unit performs an
individual PID control over its own corresponding throttling
element (i.e., the electronic expansion valve) according to the
superheat degree of its own, and a heating indoor unit performs an
individual PID control over its own corresponding throttling
element (i.e., the electronic expansion valve) according to the
subcooling degree of itself, and transmits the relevant parameter
to the distribution device. Then, the cooling indoor unit transmits
the temperature value (such as the outlet temperature of the indoor
heat exchanger of the cooling indoor unit) detected by its own
temperature sensor to the distribution device such that the
distribution device takes an average value (i.e., T2bAverage)
according to the outlet temperature of the indoor heat exchanger of
the cooling indoor unit. Then, the distribution device calculates
the value of superheat degree of the distribution device according
to the different situations as follows:
[0047] When the flow rate of the refrigerant passing through the
first electronic expansion valve is less than the second preset
value (i.e., in case of a small flow rate), the cooling requirement
is low, the heat exchange amount of the first heat exchange
assembly is small, and the temperature of the refrigerant
discharged to the outdoor unit from the first heat exchange
assembly is near to the temperature of the refrigerant flowing into
the second heat exchange assembly, and the value of superheat
degree of the distribution device=the temperature of the
refrigerant discharged to the outdoor unit from the first heat
exchange assembly-the temperature of the refrigerant flowing into
the second heat exchange assembly.
[0048] When the flow rate of the refrigerant passing through the
first electronic expansion valve is greater than the first preset
value (i.e., in case of a big flow rate), the cooling requirement
is high, the heat exchange amount of the first heat exchange
assembly is big, and the temperature of the refrigerant discharged
to the outdoor unit from first heat exchange assembly is much
higher than the temperature of the refrigerant flowing into the
second heat exchange assembly. At this moment, if the value of
superheat degree of the distribution device is calculated using a
calculating method in case of a small flow rate to adjust the
opening of the second electronic expansion valve and the third
electronic expansion valve, the real superheat degree of the
distribution device may not be reflected, and the opening of the
two electronic expansion valves is bigger and bigger, which leads
to a bypass of lots of liquid refrigerant and affects the cooling
effect of the cooling indoor unit. However, at this moment, the
distribution device may calculate the average temperature (i.e.,
T2bAverage) according to the outlet temperature of the indoor heat
exchanger of the cooling indoor unit transmitted by the cooling
indoor unit, and the value of superheat degree of the distribution
device=T2bAverage-the temperature of the refrigerant flowing into
the second heat exchange assembly, and the opening of the second
electronic expansion valve and the third electronic expansion valve
is controlled according to the calculated value of superheat degree
to make it reach a target superheat degree. At this moment, the
control technique of the superheat degree may truly reflect the
superheat degree of the system, and thus an influence of an
improper control of the superheat degree on the cooling effect of
the indoor unit may be avoided.
[0049] By the multi-split system according to embodiments of the
present disclosure, the distribution device acquires a flow rate of
the refrigerant passing through the first electronic expansion
valve first, and when the flow rate of the refrigerant passing
through the first electronic expansion valve is greater than a
first preset value, the distribution device acquires an outlet
temperature of an indoor heat exchanger of each cooling indoor unit
of the plurality of indoor units and a temperature of the
refrigerant flowing into the second heat exchange assembly
respectively, and calculates a value of superheat degree of the
distribution device according to the an outlet temperature of an
indoor heat exchanger of each cooling indoor unit and the
temperature of the refrigerant flowing into the second heat
exchange assembly, and performs a PI control over the second
electronic expansion valve and the third electronic expansion valve
according to the calculated value of superheat degree. Therefore,
the multi-split system according to embodiments of the present
disclosure accurately acquires the value of superheat degree of the
distribution device by determining the flow rate of the refrigerant
passing through the first electronic expansion valve, which avoids
an inaccuracy of an acquired value of superheat degree caused by an
inaccuracy of the measured temperature in case of a large flow rate
or a small flow rate, and thus a failure of real reflection of a
control of superheat degree may be prevented such that an accurate
distribution of the refrigerant in a system may be realized, and an
optimal effect of simultaneous heating and cooling of the
multi-split system may be achieved.
[0050] In descriptions of the present disclosure, it is understood
that, the direction or position relationships, which are defined by
terms such as "center", "longitudinal", "lateral", "length",
"width", "thickness", "up", "down", "front", "rear", "left",
"right", "vertical", "horizontal", "top", "bottom", "inside",
"outside", "clockwise", "counterclockwise", "axial", "radial",
"circumferential", etc., are based on direction or position
relationships shown in the figures. They are only used for
convenience of describing the present disclosure and simplifying
the descriptions and are not intended to indicate or imply specific
directions, specific structures and operations which the device or
the element must have. Therefore, they cannot be understood as a
limitation to the present disclosure.
[0051] In addition, terms such as "first" and "second" are used
herein for purposes of description and are not intended to indicate
or imply relative importance or significance or imply a number of
technical features indicated. Therefore, a "first" or "second"
feature may explicitly or implicitly include one or more features.
Further, in the description, unless indicated otherwise, "a number
of" refers to two or more.
[0052] In the present disclosure, unless indicated otherwise, terms
such as "install", "connect", "couple", "fix", etc., should be
understood broadly. For example, it can be a fixed connection, it
also can be a detachable connection or an integration. It can be a
mechanical connection, or can be an electrical connection. It can
be a direct connection and also can be an indirect connection
through an intermediate media. It can be a connection inside two
elements or mutual relationships of two elements, unless indicated
otherwise. For those skilled in the art, specific meaning of the
above terms in the present disclosure can be understood according
to specific situations.
[0053] In the present disclosure, unless indicated otherwise, a
first feature "on" or "under" a second feature may include an
embodiment in which the first feature directly contacts the second
feature, and may also include an embodiment in which an additional
feature is formed between the first feature and the second feature
so that the first feature does not directly contact the second
feature. Furthermore, a first feature "on," "above," or "on top of"
a second feature may include an embodiment in which the first
feature is right or obliquely "on," "above," or "on top of" the
second feature, or just means that the first feature is at a height
higher than that of the second feature; while a first feature
"below," "under," or "on bottom of" a second feature may include an
embodiment in which the first feature is right or obliquely
"below," "under," or "on bottom of" the second feature, or just
means that the first feature is at a height lower than that of the
second feature.
[0054] Reference throughout this specification, terms "an
embodiment", "some embodiments", "one embodiment", "an example", "a
specific example", or "some examples" means that a particular
feature, structure, material, or characteristic described in
connection with the embodiment or example is included in at least
one embodiment or example of the disclosure. In the descriptions,
expressions of the above terms does not need for same embodiments
or examples. Furthermore, the feature, structure, material, or
characteristic described can be incorporated in a proper way in any
one or more embodiments or examples. In addition, under
non-conflicting condition, those skilled in the art can incorporate
or combine features described in different embodiments or
examples.
[0055] Although explanatory embodiments have been shown and
described, it would be appreciated by those skilled in the art that
the above embodiments are exemplary, shall not be construed to
limit the present disclosure, and changes, alternatives, and
modifications may be made in the embodiments within the scope of
the present disclosure.
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