U.S. patent application number 11/185763 was filed with the patent office on 2006-08-31 for variable capacity compressor and starting method thereof.
Invention is credited to Sung Hea Cho, Seung Kap Lee, Chun Mo Sung.
Application Number | 20060193732 11/185763 |
Document ID | / |
Family ID | 36932085 |
Filed Date | 2006-08-31 |
United States Patent
Application |
20060193732 |
Kind Code |
A1 |
Cho; Sung Hea ; et
al. |
August 31, 2006 |
Variable capacity compressor and starting method thereof
Abstract
A variable capacity compressor and a starting method thereof.
The variable capacity compressor includes a four-way valve having a
suction gas distribution function and an idling chamber
high-pressure injection function, thereby achieving a reduced
manufacturing cost and an improved reliability incurred by the use
of a validated component. Further, a boosting algorithm is
applicable to obtain a driving source of the four-way valve in an
initial parallel pressure state. In the variable capacity
compressor comprising a plurality of compression chambers having
different capacities and a four-way valve to distribute a suction
refrigerant gas into the plurality of compression chambers, a
starting method thereof comprises determining whether the variable
capacity compressor is in an initial starting mode, and controlling
the four-way valve to generate a pressure difference among the
plurality of compression chambers to move a piston of the four-way
valve from an initial parallel pressure state if the variable
capacity compressor is determined to be in the initial starting
mode.
Inventors: |
Cho; Sung Hea; (Suwon-Si,
KR) ; Lee; Seung Kap; (Suwon-Si, KR) ; Sung;
Chun Mo; (Hwasung-Si, KR) |
Correspondence
Address: |
STANZIONE & KIM, LLP
919 18TH STREET, N.W.
SUITE 440
WASHINGTON
DC
20006
US
|
Family ID: |
36932085 |
Appl. No.: |
11/185763 |
Filed: |
July 21, 2005 |
Current U.S.
Class: |
417/212 |
Current CPC
Class: |
F04C 2270/56 20130101;
F04C 23/008 20130101; F04C 28/06 20130101; F04C 18/3564 20130101;
F04C 28/02 20130101 |
Class at
Publication: |
417/212 |
International
Class: |
F04B 49/00 20060101
F04B049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 25, 2005 |
KR |
2005-15950 |
Claims
1. A variable capacity compressor, comprising: a plurality of
compression chambers having different capacities; a passage
switching device to supply a refrigerant gas into one of the
plurality of compression chambers to perform a compression
operation and to supply a compressed high-pressure refrigerant into
a non-operating one of the plurality of compression chambers.
2. The compressor according to claim 1, wherein the passage
switching device comprises a four-way valve to distribute a gas
into an operating compression chamber and to inject the compressed
high-pressure refrigerant into the non-operating compression
chamber.
3. The compressor according to claim 2, wherein the four-way valve
is connected to: a bypass pipe branched from an outlet pipe through
which the compressed high-pressure refrigerant is discharged, an
inlet pipe through which a suction refrigerant gas to be compressed
is supplied, and a plurality of suction pipes through which the
suction refrigerant gas from the inlet pipe to the plurality of
compression chambers is delivered to the plurality of compression
chambers, and the four-way valve selectively connects one of the
suction pipes with the inlet pipe and another one of the suction
pipes with the bypass pipe.
4. The compressor according to claim 2, further comprising: a
control unit to control a boosting operation to move a piston of
the four-way valve from an initial parallel pressure state.
5. A variable capacity compressor usable with a cooling system,
comprising: a first compression chamber having a first compression
capacity; a second compression chamber having a second compression
capacity; and a valve unit to selectively provide uncompressed gas
and compressed gas to the first and second compression chambers
according to an operation mode of the variable capacity
compressor.
6. The compressor according to claim 5, wherein the valve unit
provides uncompressed gas to an operating one of the first and
second compression chambers and provides compressed gas to a
non-operating one of the first and second compression chambers.
7. The compressor according to claim 5, wherein the first
compression capacity is a full capacity and the second compression
capacity is a partial capacity.
8. The compressor according to claim 5, wherein the valve unit
comprises: a first pipe to provide gas to the first compression
chamber; a second pipe to provide gas to the second compression
chamber; an inlet pipe to receive the uncompressed gas from a
refrigeration cycle; and a bypass pipe to receive the compressed
gas from an output of the variable capacity compressor.
9. The compressor according to claim 8, wherein the valve unit
further comprises: a valve body having a passageway disposed
therein to connect to the first, second, inlet, and bypass pipes; a
switching member disposed in the passageway to block or connect the
first, second, inlet, and bypass pipes with respect to each other;
and a driving unit to move the switching member in the
passageway.
10. The compressor according to claim 9, wherein the driving unit
comprises a piston and a solenoid.
11. The compressor according to claim 8, wherein the valve unit
has: a first operational state in which the first pipe is connected
to the inlet pipe and blocked from the bypass pipe, and the second
pipe is connected to the bypass pipe and blocked from the inlet
pipe; and a second operational state in which the first pipe is
connected to the bypass pipe and blocked from the inlet pipe, and
the second pipe is connected to the inlet pipe and blocked from the
bypass pipe.
12. A method of starting a variable capacity compressor including a
plurality of compression chambers having different compression
capacities and a four-way valve to selectively distribute a cooling
gas into the plurality of compression chambers, the method
comprising: determining whether the variable capacity compressor is
in an initial starting mode; and controlling the four-way valve to
generate a pressure difference among the plurality of compression
chambers to move a piston of the four-way valve from an initial
parallel pressure state when the variable capacity compressor is
determined to be in the initial starting mode.
13. The method according to claim 12, wherein the controlling of
the four-way valve to generate the pressure difference comprises:
operating one or more of the plurality of compression chambers;
resting the variable capacity compressor for a predetermined
waiting time; and operating one or more remaining compression
chambers after a lapse of the predetermined waiting time.
14. The method according to claim 13, wherein the one or more of
the plurality of compression chambers or the one or more remaining
compression chambers are selectively operated for a predetermined
operation time.
15. The method according to claim 13, wherein all of the plurality
of compression chambers are prevented from operating during the
predetermined waiting time.
16. The method according to claim 12, further comprising:
determining whether the variable capacity compressor is in an
intermittent operation mode.
17. The method according to claim 16, wherein the four-way valve is
controlled to generate the pressure difference among the plurality
of compression chambers to move the piston of the four-way valve
when the variable capacity compressor is determined to be in the
intermittent operation mode.
18. The method according to claim 16, wherein, in the intermittent
operation mode, the variable capacity compressor restarts operation
after a lapse of a predetermined rest time.
19. The method according to claim 12, wherein the determining of
whether the variable capacity compressor is in the initial starting
mode comprises determining whether the variable capacity compressor
is in a cold starting mode or a hot starting mode.
20. The method according to claim 19, further comprising:
determining whether the variable capacity compressor is in an
intermittent operation mode or a continuous operation mode when it
is determined that the variable capacity compressor is in the hot
starting mode.
21. The method according to claim 20, wherein the controlling of
the four-way valve to generate the pressure difference among the
plurality of compression chambers is performed when the variable
capacity compressor is in the cold starting mode or the
intermittent starting mode.
22. The method according to claim 12, further comprising: operating
a first compression chamber for a first predetermined operation
time; resting the variable capacity compressor for a first
predetermined rest time; and operating a second compression chamber
for a second predetermined operation time.
23. The method according to claim 22, wherein: the operating of the
first compression chamber comprises operating at a 100% compression
capacity for the first predetermined operation time; and the
operation of the second compression chamber comprises operating at
a 40% compression capacity for the second predetermined operation
time.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2005-15950, filed on Feb. 25, 2005 in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present general inventive concept relates to a variable
capacity compressor, and more particularly, to a variable capacity
compressor which includes a four-way valve having a suction gas
distribution function and a high-pressure injection function, and
is designed to gain a driving source of the four-way valve in an
initial parallel pressure state. The present general inventive
concept further relates to a starting method of the variable
capacity compressor.
[0004] 2. Description of the Related Art
[0005] Cooling systems designed to cool an enclosed surrounding
space using a refrigeration cycle, such as air conditioners and
refrigerators, include a compressor to compress a refrigerant that
circulates in a closed circuit of the refrigeration cycle. A
cooling capability of the cooling systems is determined depending
on a compression capacity of the compressor.
[0006] Variable capacity compressors that are capable of varying
the compression capacity used to compress the refrigerant have been
used to perform optimum cooling consistent with a need to conserve
energy by varying the cooling ability thereof.
[0007] An example of the variable capacity compressors is disclosed
in Korean Patent Application No. 2002-61462 filed by the applicant
of the present general inventive concept. The disclosed variable
capacity compressor is designed such that only one of two
compression chambers having different compression capacities
selectively performs a compression operation.
[0008] The variable capacity compressor of the above Korean patent
application includes an eccentric device that causes a roller,
disposed in an associated one of the compression chambers, to be
eccentrically rotated or to be released from its eccentrically
rotated position depending on a change of a rotational direction of
a rotary shaft in the associated compression chamber, thereby
selectively performing a compression or compression-removal
operation. The eccentric device includes two eccentric cams
provided at an outer circumference of the rotary shaft in the
respective compression chambers, two eccentric bushes rotatably
coupled, respectively, to outer circumferences of the two eccentric
cams, two rollers rotatably coupled, respectively, to outer
circumferences of the two eccentric bushes, and a latch pin to
latch one of the two eccentric bushes to its eccentric position and
the other one to its non-eccentric position during rotation of the
rotary shaft. The eccentric device further includes radially
reciprocatable vanes disposed in the compression chambers,
respectively, to divide an interior of the respective compression
chambers into a suction space and a discharge space.
[0009] With the variable capacity compressor configured as
described above, one of the compression chambers having different
capacities performs an idling operation when the other compression
chamber performs a compression operation according to operation of
the eccentric device, thereby enabling a variable capacity
operation of the compressor as a result of changing a rotational
direction of the rotary shaft.
[0010] The above described variable capacity compressor is easy to
install in an air conditioner because of its simplified structure
having a suction gas distribution device that is directly attached
to the compressor. However, the design and manufacture of the
separate distribution device results in the use of an un-validated
component, thereby deteriorating a reliability of the
compressor.
[0011] Further, the roller of the compression chamber having no
source of a refrigerant, i.e., an idling compression chamber,
continuously rotates along with the rotary shaft, thereby
generating a negative pressure in the idling compression chamber
due to a pressure difference between the idling compression chamber
and an interior of a hermetic casing of the compressor. The
negative pressure hinders a rotation of the rotary shaft, resulting
in a deterioration in an operational efficiency of the compressor
due to power loss.
[0012] In order to solve the above problem, it is necessary to
provide a separate control device to inject a high-pressure
refrigerant to an idling portion of the compressor to equalize the
interior pressure and a discharge pressure of the idling
compression chamber. However, this increases manufacturing
costs.
SUMMARY OF THE INVENTION
[0013] The present general inventive concept provides a variable
capacity compressor including a four-way valve having a suction gas
distribution function and an idling chamber high-pressure injection
function, thereby achieving a low manufacturing cost and a high
reliability due to the use of a validated component.
[0014] The present general inventive concept also provides a
starting method of a variable capacity compressor that performs a
boosting algorithm to obtain a driving source of a four-way valve
in an initial parallel pressure state to produce a pressure
difference to move a piston of the four-way valve.
[0015] Additional aspects and/or advantages of the general
inventive concept will be set forth in part in the description
which follows and, in part, will be obvious from the description,
or may be learned by practice of the general inventive concept.
[0016] The foregoing and/or other aspects and advantages of the
present general inventive concept are achieved by providing a
variable capacity compressor comprising a plurality of compression
chambers having different capacities, a passage switching device to
supply a refrigerant gas into one of the plurality of compression
chambers to perform a compression operation and to supply a
compressed high-pressure refrigerant into a non-operating one of
the plurality of compression chambers.
[0017] The passage switching device may be a four-way valve to
distribute a gas into an operating compression chamber and to
inject the compressed high-pressure refrigerant into the
non-operating compression chamber.
[0018] The four-way valve may be connected to a bypass pipe
branched from an outlet pipe through which the compressed
high-pressure refrigerant is discharged, an inlet pipe through
which a suction refrigerant gas to be compressed is supplied, and a
plurality of suction pipes through which the suction refrigerant
gas from the inlet pipe is delivered to the plurality of
compression chambers, and the four way valve selectively connects
one of the suction pipes with the inlet pipe and another one of the
suction pipes with the bypass pipe.
[0019] The compressor may further comprise a control unit to
control a boosting operation to move a piston of the four-way valve
into an initial parallel pressure state.
[0020] The foregoing and/or other aspects and advantages of the
present general inventive concept are also achieved by providing a
starting method of a variable capacity compressor including a
plurality of compression chambers having different capacities and a
four-way valve to selectively distribute a refrigerant gas into the
plurality of compression chambers, the method comprising
determining whether the variable capacity compressor is in an
initial starting mode, and controlling the four-way valve to
generate a pressure difference to move a piston of the four-way
valve in an initial parallel pressure state if the variable
capacity compressor is determined to be in the initial starting
mode.
[0021] The controlling of the four-way valve to generate the
pressure difference may comprise operating one or more of the
plurality of compression chambers and successively operating one or
more remaining compression chambers after a lapse of a
predetermined waiting time.
[0022] The one or more of the plurality of compression chambers or
the one or more remaining compression chambers may be selectively
operated for a predetermined operation time, and all of the
plurality of compression chambers may be stopped from operating
during the predetermined waiting time.
[0023] The method may further comprise determining whether the
variable capacity compressor is in an intermittent operation
mode.
[0024] If the compressor is in the intermittent operation mode, the
four-way valve may be controlled to generate the pressure
difference to move the piston of the four-way valve, and the
variable capacity compressor may restart operation after a lapse of
a predetermined rest time in the intermittent operation mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and/or other aspects and advantages of the exemplary
embodiments of the general inventive concept will become apparent
and more readily appreciated from the following description of the
embodiments, taken in conjunction with the accompanying drawings,
of which:
[0026] FIG. 1 is a vertical sectional view illustrating a variable
capacity compressor according an embodiment of the present general
inventive concept;
[0027] FIG. 2 is a schematic diagram illustrating a refrigeration
cycle of the variable capacity compressor of FIG. 1;
[0028] FIG. 3 is a sectional view illustrating an operational state
of a four-way valve to permit a compression operation of a first
compression chamber included in the variable capacity compressor of
FIG. 1;
[0029] FIG. 4 is a sectional view illustrating another operational
state of a four-way valve to permit a compression operation of a
second compression chamber included in the variable capacity
compressor of FIG. 1;
[0030] FIG. 5 is a control block diagram illustrating a starting
system of the variable capacity compressor of FIG. 1 according to
an embodiment of the present general inventive concept; and
[0031] FIG. 6 is a flow chart illustrating an operational sequence
of a starting method of the variable capacity compressor of FIG. 1
according to an embodiment of the present general inventive
concept.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Reference will now be made in detail to exemplary
embodiments of the present general inventive concept, examples of
which are illustrated in the accompanying drawings, wherein like
reference numerals refer to like elements throughout. The
embodiments are described below to explain the present general
inventive concept by referring to the figures.
[0033] FIG. 1 is a vertical sectional view illustrating a variable
capacity compressor 10 according to an embodiment of the present
general inventive concept.
[0034] Referring to FIG. 1, the variable capacity compressor 10
includes a cylindrical hermetic casing 110 to house some of the
components of the variable capacity compressor 10 including a
driving unit 120 to generate a rotational power and a compressing
unit 130 to compress a refrigerant upon receiving the power from
the driving unit 120.
[0035] The driving unit 120 includes a cylindrical stator 121 fixed
on an inner circumference of the hermetic casing 110 and a rotor
122 rotatably disposed in the stator 121 through which a rotary
shaft 123 is inserted at a hollow center portion thereof. The
driving unit 120 rotates the rotary shaft 123 in a forward or
reverse direction.
[0036] The compressing unit 130 includes an upper first cylinder
131 and a lower second cylinder 132 that are axially stacked in
parallel and define first and second compression chambers 131a and
132a having different compression capacities, respectively. For
example, the first compression chamber 131a may have a capacity of
100% and the second compression chamber 132a may have a capacity of
40%. Other compression capacities may alternatively be used which
provide the purposes intended, as described herein. The compressing
unit 130 further includes upper and lower flanges 133 and 134 to
close an upper end of the first compression chamber 131a and a
lower end of the second compression chamber 132a, respectively. A
partition 135 is interposed between the first and second
compression chambers 131a and 132a to separate them from each
other.
[0037] A first suction pipe 72a is connected to a lateral side of
the first cylinder 131 to direct a low-pressure refrigerant,
delivered via an inlet pipe 70, to the first compression chamber
131a. A second suction pipe 72b is connected to a lateral side of
the second cylinder 132 (i.e., on the same side of the compressing
unit 130 as the first suction pipe 72a) to direct the low-pressure
refrigerant to the second compression chamber 132a.
[0038] First and second eccentric units 123a and 123b are disposed
on the rotary shaft 123 such that they are eccentrically rotatable
in the first and second compression chambers 131a and 132a,
respectively. First and second rollers 136a and 136b are rotatably
coupled to outer circumferences of the first and second eccentric
units 123a and 123b, respectively.
[0039] Although not shown, each of the compression chambers 131a
and 132a may have a vane that is elastically supported at an end
thereof by an outer circumference of the roller 136a or 136b, and
is adapted to divide an interior of the compression chambers 131a
and 132a into a refrigerant suction space and a refrigerant
discharge space.
[0040] An outlet pipe 71 is disposed at an upper end of the
hermetic casing 110 to discharge a compressed refrigerant from the
variable capacity compressor 10.
[0041] The variable capacity compressor 10 according to the
embodiment of FIG. 1 achieves a compression capacity variation by
allowing a refrigerant to be compressed in one of the first and
second compression chambers 131a and 132a having different
capacities. Accordingly, the variable capacity compressor 10
includes a channel switching device to selectively connect the
inlet pipe 70 with either the first suction pipe 72a or second
suction pipe 72b.
[0042] The channel switching device is designed to return part of a
compressed high-pressure refrigerant, discharged from the outlet
pipe 71, into one of the first or second compression chambers 131a
or 132a having no source of a refrigerant, in order to prevent a
negative pressure from being generated in the corresponding
compression chamber 131a or 132a.
[0043] The channel switching device may be a four-way valve 60 that
may be operated by a solenoid. A bypass pipe 73 is connected
between a certain position of the outlet pipe 71 and the four-way
valve 60 to direct part of the compressed high-pressure
refrigerant, discharged from the outlet pipe 71, into the four-way
valve 60.
[0044] FIG. 2 is a schematic diagram illustrating a refrigeration
cycle using the variable capacity compressor 10 according to FIG.
1.
[0045] Referring to FIG. 2, the refrigeration cycle includes the
variable capacity compressor 10, a condenser 20 to cool a
high-pressure, high-temperature refrigerant gas compressed by the
variable capacity compressor 10, an expander 30 to decompress the
refrigerant received from the condenser 20, and an evaporator 40 to
evaporate the decompressed refrigerant from the expander 30 through
heat absorption.
[0046] FIGS. 3 and 4 are sectional views illustrating different
operational states of the four-way valve 60. FIG. 3 illustrates a
first operational state that permits a compression operation of the
first compression chamber 131a, and FIG. 4 illustrates a second
operational state that permits a compression operation of the
second compression chamber 132a.
[0047] Referring to FIGS. 3 and 4, the four-way valve 60 includes a
body 61, a solenoid 62, a piston 63, and a channel switching member
64. The body 61 has four ports including an inlet port 61a
connected to the inlet pipe 70, a first suction port 61b connected
to the first suction pipe 72a, a second suction port 61c connected
to the second suction pipe 72b, and a bypass port 61d connected to
the bypass pipe 73. The solenoid 62 is installed in a lateral
region of the body 61 to generate a magnetic field using a source
of electric power. The piston 63 is reciprocally movable according
to the magnetic field generated by the solenoid 62. The channel
switching member 64 is connected to the piston 63 to reciprocally
move along with the piston 63, thereby connecting each of the
bypass pipe 73 and the inlet pipe 70 with one of the first suction
pipe 72a and the second suction pipe 72b.
[0048] Depending on a position of the channel switching member 64,
the four-way valve 60 simultaneously performs both a suction gas
distribution function to supply a suction refrigerant gas into one
of the first and second compression chambers 131a or 132a for
compression therein via the inlet pipe 70, and a high-pressure
refrigerant injection function to supply a compressed high-pressure
refrigerant gas into the other one of the first and second
compression chambers 131a and 132a having no source of the suction
refrigerant gas (i.e., an idling chamber) via the bypass pipe
73.
[0049] In the first operational state in which no electric power is
applied to the solenoid 62, as illustrated in FIG. 3, the channel
switching member 64 is positioned to connect the inlet pipe 70 with
the first suction pipe 72a and the bypass pipe 73 with the second
suction pipe 72b.
[0050] Since the first suction pipe 72a leads into the first
compression chamber 131a, a low-pressure refrigerant, delivered
from the evaporator 40 (see FIG. 2), is introduced into and
compressed in the first compression chamber 131a (see FIGS. 1 and
2), thereby causing the variable capacity compressor 10 (see FIGS.
1 and 2) to operate with a capacity corresponding to that of the
first compression chamber 131a (for example, a full load capacity
of 100%). Similarly, since the second suction pipe 72b leads into
the second compression chamber 132a, part of a compressed
high-pressure refrigerant, discharged from the outlet pipe 71, is
introduced into the second compression chamber 132a, thereby
preventing generation of a negative pressure in the second
compression chamber 132a.
[0051] When electric power is applied to the solenoid 62, in the
second operational state as illustrated in FIG. 4, the channel
switching member 64 is positioned to connect the inlet pipe 70 with
the second suction pipe 72b and the bypass pipe 73 with the first
suction pipe 72a.
[0052] Thus, a low-pressure refrigerant, delivered from the
evaporator 40, is introduced into and compressed in the second
compression chamber 132a, thereby causing the variable capacity
compressor 10 to operate with a capacity corresponding to that of
the second compression chamber 132a (for example, a partial load
capacity of 40%). In this case, part of a compressed high-pressure
refrigerant, discharged from the outlet pipe 71, is introduced into
the first compression chamber 131a, thereby preventing generation
of a negative pressure in the first compression chamber 131a.
[0053] FIG. 5 is a control block diagram illustrating a starting
system of the variable capacity compressor 10 of FIG. 1 according
to an embodiment of the present general inventive concept. The
starting system includes a signal input unit 200, a temperature
sensor unit 210, a control unit 220, a compressor drive unit 230,
an operational state sensor unit 240, and a four-way valve drive
unit 250.
[0054] The signal input unit 200 inputs operational information,
such as a preset temperature Ts and an operation mode selected by a
user. The temperature sensor unit 210 senses an indoor temperature
Tr if the variable capacity compressor 10 of the present general
inventive concept is applied to an air conditioner. If the variable
capacity compressor 10 is applied to a refrigerator, the
temperature sensor unit 210 senses an interior temperature Tr of
the refrigerator.
[0055] The control unit 220 is a microcomputer to perform a
boosting algorithm to obtain a driving source of the four-way valve
60 in an initial starting operation (i.e. cold starting) or
intermittent starting operation (i.e. re-starting after the lapse
of a predetermined rest time) of the variable capacity compressor
10. Here, the boosting algorithm is an algorithm to generate a
pressure difference sufficient to move the piston 63 (see FIGS. 3
and 4) of the four-way valve 60 in an initial parallel pressure
condition. The control unit 220 has a timer that counts an
operation time or rest time of the first and second compression
chambers 131a and 132a.
[0056] The control unit 220 also compares the indoor temperature Tr
with a preset temperature Ts and controls operations of the first
and second compression chambers 131a and 132a (see FIGS. 1 and 2)
based on a result of the comparison. When a temperature difference
Tr-Ts is small, the control unit 220 controls a compression
operation of the second compression chamber 132a at a low operation
capacity, and when the temperature difference Tr-Ts is large, the
control unit 220 controls a compression operation of the first
compression chamber 131a at a high operation capacity.
[0057] The compressor drive unit 230 rotates the rotary shaft 123
(see FIG. 1) in a forward or reverse direction depending on a
compressor control signal received from the control unit 220 to
independently operate the first and second compression chambers
131a and 132a. The operational state sensor unit 240 senses an
operational state of the variable capacity compressor 10 and inputs
the sensed operational state to the control unit 220 to allow the
control unit 220 to determine whether the variable capacity
compressor 10 is in cold/hot starting operation or
continuous/intermittent starting operation.
[0058] Alternatively, the control unit 220 may itself be designed
to sense the operational state of the variable capacity compressor
10.
[0059] The four-way valve drive unit 250 turns on/off the four-way
valve 60 so that, depending on a valve control signal received from
the control unit 220, the four-way valve 60 distributes a suction
refrigerant gas delivered from the evaporator 40 (see FIG. 2) into
one of the first and second compression chambers 131a and 132a for
compression and simultaneously returns part of a compressed
high-pressure refrigerant into the other one of the first and
second compression chambers 131a and 132a having no source of the
suction refrigerant gas (i.e. an idling chamber of the variable
capacity compressor 10).
[0060] Hereinafter, an operational sequence of a starting method of
the variable capacity compressor 10 is described.
[0061] FIG. 6 is a flow chart illustrating the operational sequence
of the starting method of the variable capacity compressor 10
according to an embodiment of the present general inventive
concept. The starting method of FIG. 6 is described with reference
to the starting system of FIG. 5.
[0062] In the variable capacity compressor 10, the first
compression chamber 131a (see FIGS. 1 and 2) has a large
compression capacity of 100% and the second compression chamber
132a has a small compression capacity of 40%. The four-way valve 60
(see FIGS. 1 and 2) is attached to the variable capacity compressor
10 to distribute a suction gas into one of the compression chambers
and inject a compressed refrigerant gas into an idling chamber of
the variable capacity compressor 10.
[0063] When the variable capacity compressor 10 starts to operate,
the control unit 220 determines whether the variable capacity
compressor 10 is in a cold or hot starting operation at operation
S300.
[0064] The cold starting operation refers to an initial starting
operation of the variable capacity compressor 10, and the hot
starting operation is a concept opposite to the cold starting
operation and is a non-initial starting operation of the variable
capacity compressor 10.
[0065] If the variable capacity compressor 10 is in the hot
starting operation, the control unit 220 determines whether the
variable capacity compressor 10 is in a continuous or intermittent
operation at operation S310.
[0066] The continuous operation is a case in which the variable
capacity compressor 10 restarts operation within a predetermined
rest time of approximately 15 seconds, and the intermittent
operation is a case in which the variable capacity compressor 10
restarts operation after the predetermined rest time of
approximately 15 seconds has lapsed.
[0067] If the variable capacity compressor 10 is in the
intermittent operation, the four-way valve 60 performs a boosting
algorithm to generate a pressure difference between the first
compression chamber 131a (see FIGS. 1 and 2) and the second
compression chamber 132a (see FIGS. 1 and 2) to move the piston 63
of the four-way valve 60 according to the following procedure.
[0068] First, the control unit 220 controls an operation capacity
of the variable capacity compressor 10 to a full load compression
capacity of 100% by operating the first compression chamber 131a of
the variable capacity compressor 10 via the compressor drive unit
230 at operation S320.
[0069] After the variable capacity compressor 10 reaches the full
load compression capacity, the control unit 220 monitors an
operation time of the first compression chamber 131a to determine
whether a first predetermined operation time t1 of approximately 1
minute passes) at operation S330. If the first predetermined
operation time t1 passes, the operation of the first compression
chamber 131a is stopped at operation S340.
[0070] The control unit 220 then monitors a rest time of the first
compression chamber 131a to determine whether a second
predetermined rest time t2 of approximately 15 seconds passes at
operation S350. Here, the second predetermined rest time t2
corresponds to a time required to convert to a non-operating
compression chamber. If the second predetermined rest time t2
passes, the control unit 220 controls the operation capacity of the
variable capacity compressor 10 to a partial load capacity of 40%
by operating the second compression chamber 132a via the compressor
drive unit 230 at operation S360.
[0071] After the variable capacity compressor 10 reaches the
partial load capacity, the control unit 220 monitors an operation
time of the second compression chamber 132a to determine whether a
third predetermined operation time t3 of approximately 1 minute
passes at operation S370. If the third predetermined operation time
t3 passes, the operation of the second compression chamber 132a is
stopped at operation S380.
[0072] The third predetermined operation time t3 may be set to be
equal to or different from the first predetermined operation time
t1 of the first compression chamber 131a and may be varied
according to the capacity of the variable capacity compressor
10.
[0073] If it is determined at the operation S300 that the variable
capacity compressor 10 is in the cold starting operation, i,e. in
an initial starting, the control unit 220 proceeds to the operation
S320 to enable the four-way valve 60 to perform the boosting
algorithm, in order to generate a pressure difference between the
first compression chamber 131a and the second compression chamber
132a to move the piston 63 of the four-way valve 60 in an initial
parallel pressure condition.
[0074] If the four-way valve 60 is movable as a result of the
boosting algorithm, the control unit 220 compares an indoor
temperature Tr with a preset temperature Ts and determines whether
a temperature difference Tr-Ts is more than a predetermined
standard temperature Ta at operation S390.
[0075] If the temperature difference Tr-Ts is more than the
predetermined standard temperature Ta, the control unit 220
increases the operation capacity of the variable capacity
compressor 10 to operate the first compression chamber 131a at
operation S400. If the temperature difference Tr-Ts is less than
the predetermined standard temperature Ta, the control unit 220
decreases the operation capacity of the variable capacity
compressor 10 to operate the second compression chamber 132a at
operation S410.
[0076] As apparent from the above description, according to a
variable capacity compressor and a starting method thereof
according to the present general inventive concept, a four-way
valve is employed to distribute a suction refrigerant gas into one
of a plurality of compression chambers of the variable capacity
compressor for compression and to simultaneously inject a
compressed high-pressure refrigerant gas into another compression
chamber (i.e. an idling chamber of the variable capacity
compressor) thereby achieving a reduced manufacturing cost and an
improved reliability incurred by the use of a validated component.
Further, by performing a boosting algorithm to gain a driving
source of the four-way valve, it is possible to effectively
generate a pressure difference sufficient to move a piston of the
four-way valve from an initial parallel pressure state.
[0077] Although embodiments of the present general inventive
concept have been shown and described, it should be appreciated by
those skilled in the art that changes may be made in this
embodiment without departing from the principles and spirit of the
general inventive concept, the scope of which is defined in the
claims and their equivalents.
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