Note: Descriptions are shown in the official language in which they were submitted.
TWO-PIPE ENHANCED-VAPOR-INJECTION OUTDOOR UNIT AND MULTI-SPLIT
SYSTEM
The present disclosure is based on and claims priority to Chinese Patent
Application No.
201811227632.6, filed on October 22, 2018, the entire content of which is
incorporated herein by
reference.
FIELD
The present disclosure relates to a technical field of refrigeration, and
particularly to a two-
pipe enhanced-vapor-injection outdoor unit and a two-pipe enhanced-vapor-
injection multi-split
system.
BACKGROUND
Currently, the conventional enhanced vapor injection and low-temperature
forced heat change
technologies are only used in the heat pump and the three-pipe heat recovery
system. Since the gas
return pipe of the outdoor unit in the two-pipe system just has the low
pressure, it is difficult to
achieve the enhanced vapor injection at the injection port of the compressor.
Thus, the two-pipe
multi-split system has the low pressure at the low-pressure side, the low
density of the returned
gas, and the small refrigerant circulation, and hence has the problem of
insufficient heating
capacity in the low-temperature environment, due to the low environment
temperature. Moreover,
the two-pipe system has problems of the high exhaust superheat degree and the
insufficient heating
capacity in the high-pressure environment.
SUMMARY
The present disclosure intends to at least solve one of the technical problems
existing in the
related art.
An aspect of the present disclosure provides a two-pipe enhanced-vapor-
injection outdoor
unit.
Another aspect of the present disclosure provides a two-pipe enhanced-vapor-
injection multi-
split system.
In view of the above, the present disclosure provides a two-pipe enhanced-
vapor-injection
outdoor unit. The two-pipe enhanced-vapor-injection outdoor unit includes: an
outdoor heat
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exchanger, a first port and a second port; an enhanced-vapor-injection
compressor including a gas
discharge port, a gas return port and an injection port; a reversing assembly
including a first end
connected with the gas discharge port, and a second end connected with the gas
return port; a flash
evaporator including a refrigerant inlet, a gas outlet and a liquid outlet,
the gas outlet being
connected with the injection port, the liquid outlet being connected with the
first port and an inlet
of the outdoor heat exchanger, respectively; a throttling assembly including a
first end connected
with the refrigerant inlet, and a second end connected with the second port; a
first pipe including a
first end connected with an outlet of the outdoor heat exchanger, and a second
end arranged
between the throttling assembly and the second port.
The two-pipe enhanced-vapor-injection outdoor unit provided by the present
disclosure
includes the outdoor heat exchanger, the first port, the second port, the
enhanced-vapor-injection
compressor, the reversing assembly, the flash evaporator, the throttling
assembly and the first pipe.
The first end of the reversing assembly is connected with the gas discharge
port, and the second
end of the reversing assembly is connected with the gas return port. The gas
outlet of the flash
evaporator is connected with the injection port, and the liquid outlet of the
flash evaporator is
connected with the first port and the inlet of the outdoor heat exchanger,
respectively. The
refrigerant inlet of the flash evaporator is connected with the first end of
the throttling assembly,
and the second end of the throttling assembly is connected with the second
port. The first end of
the first pipe is connected with the outlet of the outdoor heat exchanger, and
the second end of the
first pipe is arranged between the throttling assembly and the second port. In
the present
disclosure, by using the enhanced-vapor-injection compressor, the gaseous
refrigerant flowing out
of the enhanced-vapor-injection heat exchanger directly enters the compressor
through the middle
injection port of the compressor for the enhanced-vapor-injection compression.
Moreover, the
flash evaporator and the throttling assembly are added to significantly
increase a refrigerant
circulation in a heating operation at a low temperature, such that a range of
the heating operation at
the low temperature is expanded in the two-pipe enhanced-vapor-injection
outdoor unit, and also
the heating capacity is improved significantly, so as to achieve purposes of
improving the cooling
capacity at a high temperature and reducing an exhaust superheat degree.
In addition, the first pipe is added, such that the effect of enhanced vapor
injection can be
obtained in four modes, namely, a cooling mode, a heating mode, a main cooling
mode and main
heating mode.
The flash evaporator is a container that can hold the refrigerant, and usually
has three ports,
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namely the refrigerant inlet for entrance of the refrigerant gas-liquid
mixture, the gas outlet for the
refrigerant and the liquid outlet for the refrigerant. The flash evaporator
has following working
principles: the gas-liquid mixture of the refrigerant from the upstream
throttling element flows in
through the refrigerant inlet of the flash evaporator; due to the sudden
expansion of the volume, a
large amount of refrigerant flashes out from the liquid refrigerant, becomes
the refrigerant gas with
a low temperature, and flows out of the gas outlet; and the liquid refrigerant
which has not flashed
flows out of the flash evaporator from the liquid outlet. Thus, there are not
any droplets at the gas
outlet of the flash evaporator, and there is not any gas at the liquid outlet.
Since the gas outlet of the flash evaporator is connected to the injection
port, it can be ensured
that the refrigerant discharged from the gas outlet is a gaseous refrigerant
during the enhanced
vapor injection, which effectively prevents the problem of liquid impact of
the enhanced-vapor-
injection compressor, and guarantees the service life of the enhanced-vapor-
injection compressor.
The two-pipe enhanced-vapor-injection outdoor unit is a two-pipe structure,
and two
connection pipes are provided between an indoor unit and the outdoor unit.
That is, the first port
and the second port are connected with the indoor unit. Compared with the
three-pipe multi-split
system in the related art, the two-pipe heat-recovery multi-split system
provided by the present
disclosure has a simple structure, such that the cupper materials are saved,
and the mounting cost
is reduced.
In addition, the two-pipe enhanced-vapor-injection outdoor unit provided by
the present
disclosure is used in the two-pipe enhanced-vapor-injection multi-split
system, and the multi-split
system is a heat-recovery multi-split system. The heat recovery means that the
heat discharged
from the cooling room is recovered for heating of the heating room.
Specifically, the system uses
the indoor-unit heat exchanger to absorb heat from the cooling room, then the
indoor-unit heat
exchanger releases such heat completely or partially to the heating room for
heating, and the heat
lacked by the system or the remaining heat of the system is obtained from the
environment by the
outdoor-unit heat exchanger. However, for the ordinary heat-pump multi-split
system, the heat
required by the heating indoor unit totally comes from the heat absorption and
the power
consumption of the outdoor-unit heat exchanger. Thus, compared with the
ordinary heat pump, the
heat-recovery multi-split system has a significant energy-saving effect.
The heat-recovery multi-split system includes four operation modes, namely a
cooling mode,
a main cooling mode, a main heating mode and a heating mode. When all the
operating indoor
units are in the cooling mode/the heating mode, the outdoor unit operates in
the cooling mode/the
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heating mode. When a part of the operating indoor units are in the cooling
mode, another part of
the operating indoor units are in the heating mode, and the cooling load is
greater than the heating
load, the outdoor unit will operate in the main cooling mode. When a part of
the operating indoor
units are in the cooling mode, another part of the operating indoor units are
in the heating mode,
and the cooling load is less than the heating load, the outdoor unit will
operate in the main heating
mode. If the flow rate required for running the cooling indoor units is
exactly equal to the flow rate
required for running the heating indoor units, the system operates in a full
heat-recovery mode.
In addition, the two-pipe enhanced-vapor-injection outdoor unit according to
the above
technical solutions of the present disclosure further includes following
additional technical
features.
In any of the above technical solutions, preferably, the third end of the
reversing assembly is
switchably connected to the inlet of the outdoor heat exchanger or the outlet
of the outdoor heat
exchanger, and the fourth end of the reversing assembly is switchably
connected to the second port
or the first port.
In this technical solution, the third end of the reversing assembly is
switchably connected to
the inlet of the outdoor heat exchanger or the outlet of the outdoor heat
exchanger, and the fourth
end of the reversing assembly is switchably connected to the second port or
the first port. When
the two-pipe enhanced-vapor-injection multi-split system is in the cooling
mode and the main
cooling mode, the third end of the reversing assembly is connected to the
inlet of the outdoor heat
exchanger, and the fourth end of the reversing assembly is connected to the
second port. When the
two-pipe enhanced-vapor-injection multi-split system is in the heating mode
and the main heating
mode, the third end of the reversing assembly is connected to the outlet of
the outdoor heat
exchanger, and the fourth end of the reversing assembly is connected to the
first port, so as to
achieve different flow directions of the refrigerant.
In any of the above technical solutions, preferably, the two-pipe enhanced-
vapor-injection
outdoor unit includes: a first solenoid valve arranged the gas outlet and the
injection port, and
having a conduction direction from the gas outlet to the injection port.
In this technical solution, the two-pipe enhanced-vapor-injection outdoor unit
includes the
first solenoid valve. The first solenoid valve is conducted when powered on,
and is closed when
powered off. When the first solenoid valve is powered on to be conducted, the
conduction
direction of the first solenoid valve is from the gas outlet to the injection
port, i.e. a conduction
direction, in which the refrigerant is only allowed to flow from the gas
outlet to the injection port,
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so as to avoid the refrigerant backflow phenomenon.
In any of the above technical solutions, preferably, the two-pipe enhanced-
vapor-injection
outdoor unit includes a first check valve disposed in the first pipe, and the
first check valve has a
conduction direction from the outlet of the outdoor heat exchanger to the
throttling assembly.
In this technical solution, by adding the first pipe, the outlet of the
outdoor heat exchanger
and the throttling assembly are connected. The first check valve is arranged
in the first pipe, and is
added between the outlet of the outdoor heat exchanger and the throttling
assembly, so as to
prevent the gas from being exchanged between the outlet of the outdoor heat
exchanger and the
throttling assembly during heating, such that only in the cooling mode and the
main cooling mode,
the refrigerant flowing out of the outlet of the outdoor heat exchanger is
allowed to flow through
the first check valve into the throttling assembly, while in the heating mode
and the main heating
mode, the first check valve is closed, and thus the refrigerant flowing out of
the outlet of the
outdoor heat exchanger cannot pass through the first pipe.
In any of the above technical solutions, preferably, the two-pipe enhanced-
vapor-injection
outdoor unit includes: a second check valve, the second check valve connecting
the first port with
the liquid outlet, and having a conduction direction from the liquid outlet to
the first port; and a
third check valve, the third check valve connecting the second port to the
throttling assembly, and
having a conduction direction from the second port to the throttling assembly.
In this technical solution, the two-pipe enhanced-vapor-injection outdoor unit
includes the
second check valve, and the conduction direction of the second check valve is
form the liquid
outlet to the first port. A first end of the second check valve is arranged
between the liquid outlet
and the inlet of the outdoor heat exchanger, and a second end of the second
check valve is
connected with the first port. In the cooling mode and the main cooling mode,
the second check
valve is turned on, such that the refrigerant flowing out of the liquid outlet
of the flash evaporator
flows through the second check valve to the first port. In the heating mode
and the main heating
mode, the second check valve is closed, and the refrigerant flowing out of the
liquid outlet of the
flash evaporator cannot pass through the second check valve, but can only pass
through the inlet of
the outdoor heat exchanger.
Further, the two-pipe enhanced-vapor-injection outdoor unit includes the third
check valve,
and the conduction direction of the third check valve is from the second port
to the throttling
assembly. In the heating mode and the main heating mode, the third check valve
is turned on, and
the refrigerant flowing out of the second port passes through the third check
valve to the throttling
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assembly. In the cooling mode and the main cooling mode, the third check valve
is closed, and the
refrigerant flowing out of the first pipe can only flow to the throttling
assembly.
In any of the above technical solutions, preferably, the two-pipe enhanced-
vapor-injection
outdoor unit includes: a fourth check valve, the fourth check valve connecting
the second port to
the fourth end of the reversing assembly, and having a conduction direction
from the second port
to the fourth end of the reversing assembly; and a fifth check valve, the
fifth check valve
connecting the first port to the fourth end of the reversing assembly, and
having a conduction
direction from the fourth end of the reversing assembly to the first port.
In this technical solution, the two-pipe enhanced-vapor-injection outdoor unit
includes the
fourth check valve and the fifth check valve. The fourth check valve connects
the second port to
the fourth end of the reversing assembly, and the conduction direction of the
fourth check valve is
from the second port to the fourth end of the reversing assembly. The fifth
check valve connects
the first port to the fourth end of the reversing assembly, and the conduction
direction of the fifth
check valve is from the fourth end of the reversing assembly to the first
port. During operations in
the cooling mode and the main cooling mode, the fourth check valve is
conducted, and the fifth
check valve is closed. During operations in the heating mode and the main
heating mode, the fifth
check valve is conducted, and the fourth check valve is closed.
In any of the above technical solutions, preferably, the two-pipe enhanced-
vapor-injection
outdoor unit includes: a sixth check valve, the sixth check valve connecting
the third end of the
reversing assembly to the inlet of the outdoor heat exchanger, and having a
conduction direction
from the third end of the reversing assembly to the outdoor heat exchanger;
and a seventh check
valve, the seventh check valve connecting the third end of the reversing
assembly to the outlet of
the outdoor heat exchanger, and having a conduction direction from the outlet
of the outdoor heat
exchanger to the third end of the reversing assembly.
In this technical solution, the two-pipe enhanced-vapor-injection outdoor unit
includes the
sixth check valve and the seventh check valve. The sixth check valve and the
fifth check valve are
both connected with the third end of the reversing assembly, and the other
ends of the sixth check
valve and the seventh check valve are connected with the inlet of the outdoor
heat exchanger and
the outlet of the outdoor heat exchanger, respectively. During operations in
the cooling mode and
the main cooling mode, the sixth check valve is conducted, and the seventh
check valve is closed.
During operations in the heating mode and the main heating mode, the seventh
check valve is
conducted, and the sixth check valve is closed.
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In any of the above technical solutions, preferably, the throttling assembly
includes at least
one throttling device and at least one eighth check valve connected in series,
and the eighth check
valve has a conduction direction from the second port to the refrigerant
inlet.
In this technical solution, the throttling assembly includes the at least one
throttling device
and the at least one eighth check valve connected in series. The conduction
direction of the eighth
check valve is from the supercooler to the inlet of the outdoor heat
exchanger. One throttling
device may be connected in series with one eighth check valve, or one
throttling device may be
connected in series with a plurality of eighth check valves, or a plurality of
throttling devices may
be connected in series with one eighth check valve, so as to ensure the
effects of throttling and
depressurization, and thus a better depressurization effect can be achieved
after multi-stage
depressurizations.
In any of the above technical solutions, preferably, the two-pipe enhanced-
vapor-injection
outdoor unit includes: a second pipe connecting the gas discharge port to the
first port; and a
second solenoid valve arranged in the second pipe, and having a conduction
direction from the gas
discharge port to the first port.
In this technical solution, the two-pipe enhanced-vapor-injection outdoor unit
includes the
second pipe and the second solenoid valve arranged in the second pipe. During
the operation in the
cooling mode, the second solenoid valve is closed, and all the refrigerant
discharged from the gas
discharge port passes through the third end of the reversing assembly into the
inlet of the outdoor
heat exchanger. During the operation in the main cooling mode, the second
solenoid valve is
turned on, a part of the refrigerant discharged from the gas discharge port
passes through the third
end of the reversing assembly into the inlet of the outdoor heat exchanger,
and another part of the
refrigerant discharged from the gas discharge port passes through the second
solenoid valve into
the first port, so as to ensure that the two-pipe enhanced-vapor-injection
multi-split system can
achieve the cooling mode and the main cooling mode.
In any of the above technical solutions, preferably, the two-pipe enhanced-
vapor-injection
outdoor unit includes a ninth check valve, the ninth check valve connects the
inlet of the outdoor
heat exchanger to the liquid outlet, and has a conduction direction from the
liquid outlet to the inlet
of the outdoor heat exchanger.
In this technical solution, the two-pipe enhanced-vapor-injection outdoor unit
includes the
ninth check valve, and the conduction direction of the ninth check valve is
from the liquid outlet to
the inlet of the outdoor heat exchanger. In the cooling mode and the main
cooling mode, the ninth
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check valve is closed, and the refrigerant flowing out of the liquid outlet of
the flash evaporator
cannot pass through the ninth check valve into the inlet of the outdoor heat
exchanger, but can
only pass through the pipe, where the second check valve is, into the first
port. In the heating mode
and the main heating mode, the ninth check valve is turned on, and the
refrigerant flowing out of
the liquid outlet of the flash evaporator passes through the ninth check valve
into the inlet of the
outdoor heat exchanger.
According to an aspect of the present disclosure, a two-pipe enhanced-vapor-
injection multi-
split system is provided. The two-pipe enhanced-vapor-injection multi-split
system includes the
two-pipe enhanced-vapor-injection outdoor unit according to any of the above
technical solutions.
Therefore, the two-pipe enhanced-vapor-injection multi-split system has all
the significant effects
of the two-pipe enhanced-vapor-injection outdoor unit according to any of the
above technical
solutions.
Additional aspects and advantages of embodiments of present disclosure will be
given in the
following descriptions, become apparent in part from the following
descriptions, or be learned
from the practice of the embodiments of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and/or additional aspects and advantages of the present disclosure
will become
apparent and more readily appreciated from the following descriptions made
with reference to the
drawings, in which:
Fig. I illustrates a schematic view of a two-pipe enhanced-vapor-injection
multi-split system
provided by an embodiment of the present disclosure;
Fig. 2 illustrates another schematic view of a two-pipe enhanced-vapor-
injection multi-split
system provided by an embodiment of the present disclosure;
Fig. 3 illustrates a schematic view of a two-pipe enhanced-vapor-injection
multi-split system
in a cooling mode provided by an embodiment of the present disclosure;
Fig. 4 illustrates a schematic view of a two-pipe enhanced-vapor-injection
multi-split system
in a heating mode provided by an embodiment of the present disclosure;
Fig. 5 illustrates a schematic view of a two-pipe enhanced-vapor-injection
multi-split system
in a main cooling mode provided by an embodiment of the present disclosure;
Fig. 6 illustrates a schematic view of a two-pipe enhanced-vapor-injection
multi-split system
in a main heating mode provided by an embodiment of the present disclosure;
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Fig. 7 illustrates a pressure-enthalpy diagram of a two-pipe enhanced-vapor-
injection multi-
split system provided by an embodiment of the present disclosure.
Reference numerals:
Reference numerals in Fig. 1 to Fig. 6 have following corresponding
relationships with names
of parts.
outdoor heat exchanger, 12 first port, 14 second port, 16 enhanced-vapor-
injection
compressor, 162 gas discharge port, 164 gas return port, 166 injection port,
18 reversing
assembly, 20 flash evaporator, 202 refrigerant inlet, 204 gas outlet, 206
liquid outlet, 22
throttling assembly, 222 throttling device, 224 eighth check valve, 24 first
pipe, 26 first
solenoid valve, 28 first check valve, 30 second check valve, 32 third check
valve, 34 fourth
check valve, 36 fifth check valve, 38 sixth check valve, 40 seventh check
valve, 42 second
solenoid valve, 44 ninth check valve, 46 two-pipe enhanced-vapor-injection
indoor unit, 48
refrigerant-flow-direction switching direction, 50 gas-liquid separator, 52
first supercooler,
54 second supercooler.
DETAILED DESCRIPTION
In order to clearly understand the above objectives, features and advantages
of the present
disclosure, the present disclosure is further described in detail with
reference to the accompanying
drawings and specific embodiments. It is to be noted that, in the case of no
conflict, the
embodiments of the present disclosure and the features in the embodiments can
be combined with
each other.
In the following descriptions, many specific details are set forth so as to
provide a thorough
understanding of the present disclosure. However, the present disclosure may
be implemented in
other manners other than what are described herein. The scope protection of
the present disclosure
is not limited by the specific embodiments disclosed below.
A two-pipe enhanced-vapor-injection outdoor unit and a two-pipe enhanced-vapor-
injection
multi-split system according to an embodiment of the present disclosure will
be described with
reference to Figs. 1 to 7.
As illustrated in Figs. 1 to 6, the two-pipe enhanced-vapor-injection outdoor
unit provided by
the present disclosure includes: an outdoor heat exchanger 10, a first port 12
and a second port 14;
an enhanced-vapor-injection compressor 16 including a gas discharge port 162,
a gas return port
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164 and an injection port 166; a reversing assembly 18 including first to
fourth ends, the first end
of the reversing assembly 18 being connected with the gas discharge port 162,
the second end of
the reversing assembly 18 being connected with the gas return port 164; a
flash evaporator 20
including a refrigerant inlet 202, a gas outlet 204 and a liquid outlet 206,
the gas outlet 204 being
connected with the injection port 166, the liquid outlet 206 being connected
with the first port 12
and an inlet of the outdoor heat exchanger 10, respectively; a throttling
assembly 22 including a
first end connected with the refrigerant inlet 202, and a second end connected
with the second port
14; a first pipe 24 including a first end connected with an outlet of the
outdoor heat exchanger 10,
and a second end arranged between the throttling assembly 22 and the second
port 14.
The two-pipe enhanced-vapor-injection outdoor unit provided by the present
disclosure
includes the outdoor heat exchanger 10, the first port 12, the second port 14,
the enhanced-vapor-
injection compressor 16, the reversing assembly 18, the flash evaporator 20,
the throttling
assembly 22 and the first pipe 24. The first end of the reversing assembly 18
is connected with the
gas discharge port 162, and the second end of the reversing assembly 18 is
connected with the gas
return port 164. The gas outlet 204 of the flash evaporator 20 is connected
with the injection port
166, and the liquid outlet 206 of the flash evaporator 20 is connected with
the first port 12 and the
inlet of the outdoor heat exchanger 10, respectively. The refrigerant inlet
202 of the flash
evaporator 20 is connected with the first end of the throttling assembly 22,
and the second end of
the throttling assembly 22 is connected with the second port 14. The first end
of the first pipe 24 is
connected with the outlet of the outdoor heat exchanger 10, and the second end
of the first pipe 24
is arranged between the throttling assembly 22 and the second port 14. In the
present disclosure,
by using the enhanced-vapor-injection compressor 16, the gaseous refrigerant
flowing out of the
enhanced-vapor-injection heat exchanger directly enters the compressor through
the middle
injection port 166 of the compressor for the enhanced-vapor-injection
compression. Moreover, the
flash evaporator 20 and the throttling assembly 22 are added to significantly
increase a refrigerant
circulation in a heating operation at a low temperature, such that a range of
the heating operation at
the low temperature is expanded in the two-pipe enhanced-vapor-injection
outdoor unit, and also
the heating capacity is improved significantly, so as to achieve purposes of
improving the cooling
capacity at a high temperature and reducing an exhaust superheat degree.
In addition, the first pipe 24 is added, such that the effect of enhanced
vapor injection can be
obtained in four modes, namely, a cooling mode, a heating mode, a main cooling
mode and main
heating mode.
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The flash evaporator 20 is a container that can hold the refrigerant, and
usually has three
ports, namely the refrigerant inlet 202 for entrance of the refrigerant gas-
liquid mixture, the gas
outlet 204 for the refrigerant and the liquid outlet 206 for the refrigerant.
The flash evaporator 20
has following working principles: the gas-liquid mixture of the refrigerant
from the upstream
throttling element flows in through the refrigerant inlet 202 of the flash
evaporator 20; due to the
sudden expansion of the volume, a large amount of refrigerant flashes out from
the liquid
refrigerant, becomes the refrigerant gas with a low temperature, and flows out
of the gas outlet
204; and the liquid refrigerant which has not flashed flows out of the flash
evaporator 20 from the
liquid outlet 206. Thus, there are not any droplets at the gas outlet 204 of
the flash evaporator 20,
and there is not any gas at the liquid outlet 206.
Since the gas outlet 204 of the flash evaporator 20 is connected to the
injection port 166, it
can be ensured that the refrigerant discharged from the gas outlet 204 is a
gaseous refrigerant
during the enhanced vapor injection, which effectively prevents the problem of
liquid impact of
the enhanced-vapor-injection compressor 16, and guarantees the service life of
the enhanced-
vapor-injection compressor 16.
The two-pipe enhanced-vapor-injection outdoor unit is a two-pipe structure,
and two
connection pipes are provided between an indoor unit and the outdoor unit.
That is, the first port
12 and the second port 14 are used to be connected with the indoor unit.
Compared with the three-
pipe multi-split system in the related art, the two-pipe heat-recovery multi-
split system provided
by the present disclosure has a simple structure, such that the cupper
materials are saved, and the
mounting cost is reduced.
In addition, the two-pipe enhanced-vapor-injection outdoor unit provided by
the present
disclosure is used in the two-pipe enhanced-vapor-injection multi-split
system, and the multi-split
system is a heat-recovery multi-split system. The heat recovery means that the
heat discharged
from the cooling room is recovered for heating of the heating room.
Specifically, the system uses
the indoor-unit heat exchanger to absorb heat from the cooling room, then the
indoor-unit heat
exchanger releases such heat completely or partially to the heating room for
heating, and the heat
lacked by the system or the remaining heat of the system is obtained from the
environment by the
outdoor-unit heat exchanger. However, for the ordinary heat-pump multi-split
system, the heat
required by the heating indoor unit totally comes from the heat absorption and
the power
consumption of the outdoor-unit heat exchanger. Thus, compared with the
ordinary heat pump, the
heat-recovery multi-split system has a significant energy-saving effect.
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The heat-recovery multi-split system includes four operation modes, namely a
cooling mode,
a main cooling mode, a main heating mode and a heating mode. When all the
operating indoor
units are in the cooling mode/the heating mode, the outdoor unit operates in
the cooling mode/the
heating mode. When a part of the operating indoor units are in the cooling
mode, another part of
the operating indoor units are in the heating mode, and the cooling load is
greater than the heating
load, the outdoor unit will operate in the main cooling mode. When a part of
the operating indoor
units are in the cooling mode, another part of the operating indoor units are
in the heating mode,
and the cooling load is less than the heating load, the outdoor unit will
operate in the main heating
mode. If the flow rate required for running the cooling indoor units is
exactly equal to the flow rate
required for running the heating indoor units, the system operates in a full
heat-recovery mode.
In an embodiment provided by the present disclosure, preferably, the third end
of the
reversing assembly 18 is switchably connected to the inlet of the outdoor heat
exchanger 10 or the
outlet of the outdoor heat exchanger 10, and the fourth end of the reversing
assembly 18 is
switchably connected to the second port 14 or the first port 12.
In this embodiment, the third end of the reversing assembly 18 is switchably
connected to the
inlet of the outdoor heat exchanger 10 or the outlet of the outdoor heat
exchanger 10, and the
fourth end of the reversing assembly 18 is switchably connected to the second
port 14 or the first
port 12. When the two-pipe enhanced-vapor-injection multi-split system is in
the cooling mode
and the main cooling mode, the third end of the reversing assembly 18 is
connected to the inlet of
the outdoor heat exchanger 10, and the fourth end of the reversing assembly 18
is connected to the
second port 14. When the two-pipe enhanced-vapor-injection multi-split system
is in the heating
mode and the main heating mode, the third end of the reversing assembly 18 is
connected to the
outlet of the outdoor heat exchanger 10, and the fourth end of the reversing
assembly 18 is
connected to the first port 12, so as to achieve different flow directions of
the refrigerant.
In an embodiment provided by the present disclosure, preferably, the two-pipe
enhanced-
vapor-injection outdoor unit includes: a first solenoid valve 26 arranged the
gas outlet 204 and the
injection port 166, and having a conduction direction from the gas outlet 204
to the injection port
166.
In this embodiment, the two-pipe enhanced-vapor-injection outdoor unit
includes the first
solenoid valve 26. The first solenoid valve 26 is conducted when powered on,
and is closed when
powered off. When the first solenoid valve 26 is powered on to be conducted,
the conduction
direction of the first solenoid valve 26 is from the gas outlet 204 to the
injection port 166, i.e. a
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conduction direction, in which the refrigerant is only allowed to flow from
the gas outlet 204 to the
injection port 166, so as to avoid the refrigerant backflow phenomenon.
In an embodiment provided by the present disclosure, preferably, the two-pipe
enhanced-
vapor-injection outdoor unit includes a first check valve 28 disposed in the
first pipe 24, and the
first check valve 28 has a conduction direction from the outlet of the outdoor
heat exchanger 10 to
the throttling assembly 22.
In this embodiment, by adding the first pipe 24, the outlet of the outdoor
heat exchanger 10
and the throttling assembly 22 are connected. The first check valve 28 is
arranged in the first pipe
24, and is added between the outlet of the outdoor heat exchanger 10 and the
throttling assembly
22, so as to prevent the gas from being exchanged between the outlet of the
outdoor heat
exchanger 10 and the throttling assembly 22 during heating, such that only in
the cooling mode
and the main cooling mode, the refrigerant flowing out of the outlet of the
outdoor heat exchanger
is allowed to flow through the first check valve 28 into the throttling
assembly 22, while in the
heating mode and the main heating mode, the first check valve 28 is closed,
and thus the
refrigerant flowing out of the outlet of the outdoor heat exchanger 10 cannot
pass through the first
pipe 24.
In an embodiment provided by the present disclosure, preferably, the two-pipe
enhanced-
vapor-injection outdoor unit includes: a second check valve 30, the second
check valve 30
connecting the first port 12 with the liquid outlet 206, and having a
conduction direction from the
liquid outlet 206 to the first port 12; and a third check valve 32, the third
check valve 32
connecting the second port 14 to the throttling assembly 22, and having a
conduction direction
from the second port 14 to the throttling assembly 22.
In this embodiment, the two-pipe enhanced-vapor-injection outdoor unit
includes the second
check valve 30, and the conduction direction of the second check valve 30 is
form the liquid outlet
206 to the first port 12. A first end of the second check valve 30 is arranged
between the liquid
outlet 206 and the inlet of the outdoor heat exchanger 10, and a second end of
the second check
valve 30 is connected with the first port 12. In the cooling mode and the main
cooling mode, the
second check valve 30 is turned on, such that the refrigerant flowing out of
the liquid outlet 206 of
the flash evaporator 20 flows through the second check valve 30 to the first
port 12. In the heating
mode and the main heating mode, the second check valve 30 is closed, and the
refrigerant flowing
out of the liquid outlet 206 of the flash evaporator 20 cannot pass through
the second check valve
30, but can only pass through the inlet of the outdoor heat exchanger 10.
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Further, the two-pipe enhanced-vapor-injection outdoor unit includes the third
check valve
32, and the conduction direction of the third check valve 32 is from the
second port 14 to the
throttling assembly 22. In the heating mode and the main heating mode, the
third check valve 32 is
turned on, and the refrigerant flowing out of the second port 14 passes
through the third check
valve 32 to the throttling assembly 22. In the cooling mode and the main
cooling mode, the third
check valve 32 is closed, and the refrigerant flowing out of the first pipe 24
can only flow to the
throttling assembly 22.
In an embodiment provided by the present disclosure, preferably, the two-pipe
enhanced-
vapor-injection outdoor unit includes: a fourth check valve 34, the fourth
check valve 34
connecting the second port 14 to the fourth end of the reversing assembly 18,
and having a
conduction direction from the second port 14 to the fourth end of the
reversing assembly 18; and a
fifth check valve 36, the fifth check valve 36 connecting the first port 12 to
the fourth end of the
reversing assembly 18, and having a conduction direction from the fourth end
of the reversing
assembly 18 to the first port 12.
In this embodiment, the two-pipe enhanced-vapor-injection outdoor unit
includes the fourth
check valve 34 and the fifth check valve 36. The fourth check valve 34
connects the second port
14 to the fourth end of the reversing assembly 18, and the conduction
direction of the fourth check
valve 34 is from the second port 14 to the fourth end of the reversing
assembly 18. The fifth check
valve 36 connects the first port 12 to the fourth end of the reversing
assembly 18, and the
conduction direction of the fifth check valve 36 is from the fourth end of the
reversing assembly
18 to the first port 12. During operations in the cooling mode and the main
cooling mode, the
fourth check valve 34 is conducted, and the fifth check valve 36 is closed.
During operations in the
heating mode and the main heating mode, the fifth check valve 36 is conducted,
and the fourth
check valve 34 is closed.
In an embodiment provided by the present disclosure, preferably, the two-pipe
enhanced-
vapor-injection outdoor unit includes: a sixth check valve 38, the sixth check
valve 38 connecting
the third end of the reversing assembly 18 to the inlet of the outdoor heat
exchanger 10, and
having a conduction direction from the third end of the reversing assembly 18
to the outdoor heat
exchanger 10; and a seventh check valve 40, the seventh check valve 40
connecting the third end
of the reversing assembly 18 to the outlet of the outdoor heat exchanger 10,
and having a
conduction direction from the outlet of the outdoor heat exchanger 10 to the
third end of the
reversing assembly 18.
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In this embodiment, the two-pipe enhanced-vapor-injection outdoor unit
includes the sixth
check valve 38 and the seventh check valve 40. The sixth check valve 38 and
the fifth check valve
36 are both connected with the third end of the reversing assembly 18, and the
other ends of the
sixth check valve 38 and the seventh check valve 40 are connected with the
inlet of the outdoor
heat exchanger 10 and the outlet of the outdoor heat exchanger 10,
respectively. During operations
in the cooling mode and the main cooling mode, the sixth check valve 38 is
conducted, and the
seventh check valve 40 is closed. During operations in the heating mode and
the main heating
mode, the seventh check valve 40 is conducted, and the sixth check valve 38 is
closed.
In an embodiment provided by the present disclosure, preferably, the
throttling assembly 22
includes at least one throttling device 222 and at least one eighth check
valve 224 connected in
series, and the eighth check valve 224 has a conduction direction from the
second port 14 to the
refrigerant inlet 202.
In this embodiment, the throttling assembly 22 includes the at least one
throttling device 222
and the at least one eighth check valve 224 connected in series. The
conduction direction of the
eighth check valve 224 is from the supercooler to the inlet of the outdoor
heat exchanger 10. One
throttling device 222 may be connected in series with one eighth check valve
224, or one throttling
device 222 may be connected in series with a plurality of eighth check valves
224, or a plurality of
throttling devices 222 may be connected in series with one eighth check valve
224, so as to ensure
the effects of throttling and depressurization, and thus a better
depressurization effect can be
achieved after multi-stage depressurizations.
In an embodiment provided by the present disclosure, preferably, the two-pipe
enhanced-
vapor-injection outdoor unit includes: a second pipe connecting the gas
discharge port 162 to the
first port 12; and a second solenoid valve 42 arranged in the second pipe, and
having a conduction
direction from the gas discharge port 162 to the first port 12.
In this embodiment, the two-pipe enhanced-vapor-injection outdoor unit
includes the second
pipe and the second solenoid valve 42 arranged in the second pipe. During the
operation in the
cooling mode, the second solenoid valve 42 is closed, and all the refrigerant
discharged from the
gas discharge port 162 passes through the third end of the reversing assembly
18 into the inlet of
the outdoor heat exchanger 10. During the operation in the main cooling mode,
the second
solenoid valve 42 is turned on, a part of the refrigerant discharged from the
gas discharge port 162
passes through the third end of the reversing assembly 18 into the inlet of
the outdoor heat
exchanger 10, and another part of the refrigerant discharged from the gas
discharge port 162
PIOM1191471PCA
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passes through the second solenoid valve 42 into the first port 12, so as to
ensure that the two-pipe
enhanced-vapor-injection multi-split system can achieve the cooling mode and
the main cooling
mode.
In an embodiment provided by the present disclosure, preferably, the two-pipe
enhanced-
vapor-injection outdoor unit includes a ninth check valve 44, the ninth check
valve 44 connects the
inlet of the outdoor heat exchanger 10 to the liquid outlet 206, and has a
conduction direction from
the liquid outlet 206 to the inlet of the outdoor heat exchanger 10.
In this embodiment, the two-pipe enhanced-vapor-injection outdoor unit
includes the ninth
check valve 44, and the conduction direction of the ninth check valve 44 is
from the liquid outlet
206 to the inlet of the outdoor heat exchanger 10. In the cooling mode and the
main cooling mode,
the ninth check valve 44 is closed, and the refrigerant flowing out of the
liquid outlet 206 of the
flash evaporator 20 cannot pass through the ninth check valve 44 into the
inlet of the outdoor heat
exchanger 10, but can only pass through the pipe, where the second check valve
30 is, into the first
port 12. In the heating mode and the main heating mode, the ninth check valve
44 is turned on, and
the refrigerant flowing out of the liquid outlet 206 of the flash evaporator
20 passes through the
ninth check valve 44 into the inlet of the outdoor heat exchanger 10.
According to an aspect of the present disclosure, a two-pipe enhanced-vapor-
injection multi-
split system is provided. The two-pipe enhanced-vapor-injection multi-split
system includes the
two-pipe enhanced-vapor-injection outdoor unit according to any of the above
embodiments.
Therefore, the two-pipe enhanced-vapor-injection multi-split system has all
the significant effects
of the two-pipe enhanced-vapor-injection outdoor unit according to any of the
above
embodiments.
The two-pipe enhanced-vapor-injection multi-split system includes a
refrigerant-flow-
direction switching device 48, and the refrigerant-flow-direction switching
device 48 includes a
gas-liquid separator 50 for shunting of the gas-liquid two-phase refrigerant.
A plate heat exchanger
is used for obtaining a supercooling degree of a liquid refrigerant. Multiple
groups of solenoid
valves are used to switch the flow direction of the refrigerant.
As illustrated in Fig. 3, during cooling, the high-temperature and high-
pressure gaseous
refrigerant comes out of the enhanced-vapor-injection compressor 16, passes
through the reversing
assembly 18 and the sixth check valve 38, and then flows through the outdoor
heat exchanger 10
to be condensed into the high-pressure liquid refrigerant. A part of the high-
pressure liquid
refrigerant passes through the throttling assembly 22 to be throttled and
depressurized into the
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two-phase refrigerant, and the two-phase refrigerant enters the flash
evaporator 20. The gaseous
refrigerant passes through the first solenoid valve 26 into the injection port
166 of the enhanced-
vapor-injection compressor 16. Another part of the liquid refrigerant passes
through the second
check valve 30 to the first port 12 (an output pipe), and further enters an
inlet of the gas-liquid
separator 50 of the refrigerant-flow-direction switching direction 48.
As illustrated in Fig. 4, during heating, the high-temperature and high-
pressure gaseous
refrigerant comes out of the enhanced-vapor-injection compressor 16, passes
through two paths,
i.e. the second solenoid valve 42 as well as the reversing assembly 18 and the
fifth check valve 36,
to the high pressure valve, respectively, then flows from the high pressure
valve to the inlet of the
refrigerant-flow-direction switching device 48 through the first port 12 (the
output pipe of the
outdoor unit), further enters the gas-liquid separator 50, and then enters the
two-pipe enhanced-
vapor-injection indoor unit 46 through the gas pipe from a gas outlet of the
gas-liquid separator 50
after passing through the heating solenoid valve. After being condensed into
the high-pressure
liquid refrigerant in the two-pipe enhanced-vapor-injection indoor unit 46,
the refrigerant flows
through the electronic expansion valve of the indoor unit, and becomes the
high-pressure two-
phase refrigerant. The high-pressure two-phase refrigerant flows through the
throttling element
(whose opening is maintained to be fully opened so as to reduce the resistance
as much as
possible) of the refrigerant-flow-direction switching device 48, returns to
the second port 14 (an
input pipe of the outdoor unit), passes through the low pressure valve into
the two-pipe enhanced-
vapor-injection outdoor unit, further passes through the main throttling
assembly 22 of the outdoor
unit and then enters the inlet of the flash evaporator 20 after passing
through the third check valve
32. After flowing out of the liquid outlet 206, a liquid part of the
refrigerant enters the outdoor heat
exchanger 10 to absorb heat, further passes through the reversing assembly 18,
returns to a low-
pressure tank, and then enters the gas return port 164 of the enhanced-vapor-
injection compressor
16. After flowing out of the gas outlet 204 of the flash evaporator 20,
another gaseous part of the
refrigerant enters a compression chamber of the enhanced-vapor-injection
compressor 16 through
the first solenoid valve 26.
As illustrated in Fig. 5, during main cooling, the high-temperature and high-
pressure gaseous
refrigerant comes out of the enhanced-vapor-injection compressor 16, a part of
the high-
temperature and high-pressure gaseous refrigerant passes through the reversing
assembly 18 and
the sixth check valve 38, and further flows through the outdoor heat exchanger
10 to be condensed
into the high-pressure liquid refrigerant. A part of the high-pressure liquid
refrigerant passes
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through the throttling assembly 22 to be throttled and depressurized into the
two-phase refrigerant.
The two-phase refrigerant enters the flash evaporator 20, and the gaseous
refrigerant passes
through the first solenoid valve 26 into the injection port 166 of the
enhanced-vapor-injection
compressor 16. Another part of the liquid refrigerant passes through the
second check valve 30 to
the first port 12, and is mixed with another part of the high-temperature and
high-pressure gaseous
refrigerant, which comes out of the enhanced-vapor-injection compressor 16 and
passes through
the second solenoid valve 42, into the high-temperature and high-pressure tow-
phase refrigerant,
and enters the inlet of the gas-liquid separator 50 of the refrigerant-flow-
direction switching
direction 48. The gaseous refrigerant comes out of the gas outlet, flows
through the heating
solenoid valve, enters the gas pipe of the heating two-pipe enhanced-vapor-
injection indoor unit
46, further flows into the heating two-pipe enhanced-vapor-injection indoor
unit 46 to be
condensed, then returns to an inlet of a second supercooler 54 of the
refrigerant distributor after
passing through the throttling element of the two-pipe enhanced-vapor-
injection indoor unit 46,
further is mixed with the liquid refrigerant coming out of the liquid outlet
of the gas-liquid
separator 50 and being supercooled by the first supercooler 52, and then
enters the cooling two-
pipe enhanced-vapor-injection indoor unit 46 after being further supercooled
by the second
supercooler 54. After being depressurized by the throttling element of the
cooling two-pipe
enhanced-vapor-injection indoor unit 46, the refrigerant evaporates and
absorbs heat in the cooling
two-pipe enhanced-vapor-injection indoor unit 46, and becomes the low-pressure
gaseous
refrigerant. Then, the low-pressure gaseous refrigerant returns to the second
port 14 of the two-
pipe enhanced-vapor-injection outdoor unit through the cooling solenoid valve.
The refrigerant
further passes through the fourth check valve 34 and the reversing assembly
18, returns to the low-
pressure tank ACC, and then flows back to the gas return port 164 of the
enhanced-vapor-injection
compressor 16.
As illustrated in Fig. 6, during main heating, the high-temperature and high-
pressure gaseous
refrigerant comes out of the enhanced-vapor-injection compressor 16, passes
through two paths,
i.e. the second solenoid valve 42 as well as the reversing assembly 18 and the
fifth check valve 36,
to the high pressure valve, respectively, then flows from the high pressure
valve to the inlet of the
refrigerant-flow-direction switching device 48 through the first port 12, and
further enters the gas-
liquid separator 50. The high-pressure gaseous refrigerant comes out of the
gas outlet of the gas-
liquid separator 50, passes through the heating solenoid valve, and enters the
heating two-pipe
enhanced-vapor-injection indoor unit 46 through the gas pipe. The condensed
high-pressure liquid
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refrigerant passes through the electronic expansion valve of the two-pipe
enhanced-vapor-injection
indoor unit 46 and then flows back to the inlet of the second supercooler 54
of the refrigerant
distributor. The refrigerant becomes the high-pressure liquid refrigerant
after flowing out of the
second supercooler 54 and enters the cooling two-pipe enhanced-vapor-injection
indoor unit 44 via
the cooling check valve. The refrigerant becomes the medium-pressure two-phase
refrigerant after
being throttled by the electronic expansion valve, enters the two-pipe
enhanced-vapor-injection
indoor unit 46 to evaporate and absorb heat, and hence becomes the medium-
pressure gaseous
refrigerant. The medium-pressure gaseous refrigerant is converged with the
medium-pressure two-
phase refrigerant flowing through the throttling element of the refrigerant
distributor in the low-
pressure pipe, and further returns to the two-pipe enhanced-vapor-injection
outdoor unit through
the second port 14. After passing through the third check valve 32, and
further being throttled and
depressurized by the throttling assembly 22, the refrigerant enters the inlet
of the flash evaporator
20. The liquid refrigerant flows out of the liquid outlet 206, passes through
the ninth check valve
44 into the outdoor heat exchanger 10 to evaporate and absorb heat, further
flows through the
reversing assembly 18 into the low-pressure tank, and then returns to the gas
return port 164 of the
enhanced-vapor-injection compressor 16. The gaseous refrigerant flows out of
the gas outlet 204
of the flash evaporator 20, passes through the first solenoid valve 26, and
enters the injection port
166 of the enhanced-vapor-injection compressor 16.
As illustrated in Fig. 7, during cooling, since the two-pipe enhanced-vapor-
injection multi-
split system increases the enthalpy difference (hA_J>hA-E ), it can achieve
the same capability with
a smaller refrigerant circulation, such that the enhanced-vapor-injection
compressor 16 can have a
low frequency and make less work, so as to improve the energy efficiency. In
addition, since the
two-pipe enhanced-vapor-injection multi-split system decreases the exhaust
superheat degree
(SH<SH'), the enhanced vapor injection can increase the refrigerant
circulation and hence improve
the cooling capability during the high-temperature cooling.
In the description of the present specification, terms such as "up" and "down"
indicate the
orientation or position relationship based on the orientation or position
relationship illustrated in
the drawings only for convenience of description or for simplifying
description of the present
disclosure, and do not alone indicate or imply that the device or element
referred to must have a
particular orientation or be constructed and operated in a specific
orientation, and hence cannot be
construed as a limitation to the present disclosure. The terms "connected,"
"mounted," "fixed"
should be understood broadly. For example, "connected" may indicate fixed
connections,
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PIOM1191471PCA
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detachable connections, or integral connections; may also be direct
connections or indirect
connections via intervening structures, which can be understood by those
skilled in the art
according to specific situations.
Reference throughout this specification to terms "one embodiment," "some
embodiments," "a
specific example," "an 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 present disclosure. In this
specification, exemplary
descriptions of aforesaid terms are not necessarily referring to the same
embodiment or example.
Moreover, the particular features, structures, materials, or characteristics
described may be
combined in any suitable manner in one or more embodiments or examples.
The above embodiments are only preferred embodiments of the present
disclosure, and
should not be construed to limit the present disclosure. It can be understood
by those skilled in the
related art that the present disclosure may have various modifications and
changes. Any
modifications, equivalents, and improvements made without departing from
spirit and principles
of the present disclosure should be fallen into the protection scope of the
present disclosure.
PIOM1191471PCA
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