U.S. patent application number 14/419947 was filed with the patent office on 2015-07-23 for variable volume receiver for refrigerating cycle, refrigerating cycle comprising the variable receiver, and method for controlling the refrigerating cycle.
This patent application is currently assigned to KOREA INSTITUTE OF ENERGY RESEARCH. The applicant listed for this patent is KOREA INSTITUTE OF ENERGY RESEARCH. Invention is credited to Young Jin Baik, Ki-Chang Chang, Minsung Kim, Young-Soo Lee, Ho-Sang Ra.
Application Number | 20150204590 14/419947 |
Document ID | / |
Family ID | 50183877 |
Filed Date | 2015-07-23 |
United States Patent
Application |
20150204590 |
Kind Code |
A1 |
Baik; Young Jin ; et
al. |
July 23, 2015 |
VARIABLE VOLUME RECEIVER FOR REFRIGERATING CYCLE, REFRIGERATING
CYCLE COMPRISING THE VARIABLE RECEIVER, AND METHOD FOR CONTROLLING
THE REFRIGERATING CYCLE
Abstract
A variable volume receiver for a refrigerating cycle, according
to the present invention, can adjust the capacity of storing a
refrigerant according to changes in driving conditions, such as
outside air temperature or a load-side temperature, and can secure
a proper degree of sub-cooling even when the driving conditions
change, thereby providing the advantage of enabling optimum driving
regardless of changes in the outside air temperature or the
load-side temperature.
Inventors: |
Baik; Young Jin; (Daejeon,
KR) ; Kim; Minsung; (Daejeon, KR) ; Chang;
Ki-Chang; (Daejeon, KR) ; Lee; Young-Soo;
(Seoul, KR) ; Ra; Ho-Sang; (Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOREA INSTITUTE OF ENERGY RESEARCH |
Daejeon |
|
KR |
|
|
Assignee: |
KOREA INSTITUTE OF ENERGY
RESEARCH
Daejeon
KR
|
Family ID: |
50183877 |
Appl. No.: |
14/419947 |
Filed: |
August 28, 2013 |
PCT Filed: |
August 28, 2013 |
PCT NO: |
PCT/KR2013/007716 |
371 Date: |
February 6, 2015 |
Current U.S.
Class: |
62/115 ;
62/498 |
Current CPC
Class: |
F25B 45/00 20130101;
F25B 40/02 20130101; F25B 2700/195 20130101; F25B 43/00 20130101;
F25B 2400/16 20130101; F25B 2700/21163 20130101; F25B 49/02
20130101 |
International
Class: |
F25B 49/02 20060101
F25B049/02; F25B 43/00 20060101 F25B043/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 30, 2012 |
KR |
10-2012-0095486 |
Claims
1. A variable volume receiver for a refrigerating cycle,
comprising: a receiver tank that is connected to a refrigerant flow
path and constitutes a refrigerant storing space in which the
refrigerant that passes through the refrigerant flow path is
temporarily stored; a variable bladder that is disposed in the
receiver tank and is contracted or expanded so that a volume of the
refrigerant storing space is reduced or decreased; a
pressure-controlling portion that is installed separately from the
refrigerant flow path, communicates with the variable bladder, is
sealed from an outside and controls pressure in the variable
bladder when a fluid that communicates with the variable bladder
and is filled in the variable bladder receives heat of the
refrigerant at an outlet of a compressor in the refrigerating
cycle; and a controller that controls the pressure-controlling
portion according to driving conditions, changes the volume of the
refrigerant storing space and controls an amount of the refrigerant
that is capable of being stored in the refrigerant storing
space.
2. A variable volume receiver for a refrigerating cycle,
comprising: a receiver tank that is connected to a refrigerant flow
path and constitutes a refrigerant storing space in which the
refrigerant that passes through the refrigerant flow path is
temporarily stored; a piston that is coupled to the receiver tank
so as to linearly make a reciprocating motion and increases or
reduces a volume of the refrigerant storing space while linearly
making a reciprocating motion; a linearly moving mechanism that
linearly makes a reciprocating motion of the piston; and a
controller that controls the linearly moving mechanism according to
driving conditions, changes the volume of the refrigerant storing
space and controls an amount of the refrigerant that is capable of
being stored in the refrigerant storing space.
3. A refrigerating cycle comprising a compressor, a condenser, an
expansion mechanism, an evaporator, and a controller, further
comprising a variable volume receiver, wherein the variable volume
receiver comprises a refrigerant storing portion which is installed
on a refrigerant flow path that connects the condenser and the
expansion mechanism and in which a refrigerant discharged from the
condenser is temporarily stored, and a volume-controlling portion
controls a volume of the refrigerant storing portion while being
contracted or expanded by a pressure-controlling portion that is
installed separately from the refrigerant flow path and sealed from
an outside, and the controller controls pressure of a fluid in the
volume-controlling portion according to driving conditions, changes
the volume of the refrigerant storing portion and controls an
amount of the refrigerant stored in the variable volume
receiver.
4. A refrigerating cycle comprising a compressor, a condenser, an
expansion mechanism, an evaporator, and a controller, further
comprising a variable volume receiver, wherein the variable volume
receiver comprises a receiver tank that is installed on a
refrigerant flow path that connects the condenser and the expansion
mechanism and constitutes a refrigerant storing space in which a
refrigerant discharged from the condenser is temporarily stored, a
variable bladder that is disposed in the receiver tank and reduces
or increases a volume of the refrigerant storing space while being
contracted or expanded, and a pressure-controlling portion that is
installed separately from the refrigerant flow path, communicates
with the variable bladder, is sealed from an outside and controls
pressure in the variable bladder when a fluid filled in the
variable bladder receives heat of the refrigerant at an outlet of
the compressor, and the controller calculates a degree of
sub-cooling according to temperature and pressure of the
refrigerant at an outlet of the condenser and controls the
pressure-controlling portion according to the calculated degree of
sub-cooling.
5. A refrigerating cycle comprising a compressor, a condenser, an
expansion mechanism, an evaporator, and a controller, further
comprising a variable volume receiver, wherein the variable volume
receiver comprises a receiver tank that is connected to a
refrigerant flow path and constitutes a refrigerant storing space
in which a refrigerant that passes through the refrigerant flow
path is temporarily stored, a piston that is coupled to the
receiver tank so as to linearly make a reciprocating motion and
increases or reduces a volume of the refrigerant storing space
while linearly making a reciprocating motion, and a linearly moving
mechanism that linearly makes a reciprocating motion of the piston,
and the controller calculates a degree of sub-cooling according to
temperature and pressure of the refrigerant at an outlet of the
condenser and controls the linearly moving mechanism according to
the calculated degree of sub-cooling.
6. The refrigerating cycle of claim 4, wherein the
pressure-controlling portion comprises a pressure-controlling pipe
which communicates with the variable bladder and in which a fluid
that is evaporated by receiving heat of a high-temperature
refrigerant at the outlet of the compressor is filled.
7. The refrigerating cycle of claim 4, wherein the
pressure-controlling portion comprises a pressure-controlling pipe
which communicates with the variable bladder and in which the fluid
is filled; and a heat-exchanging portion that is installed at a
discharging side of the compressor and performs or blocks
heat-exchanging between the high-temperature refrigerant at the
outlet of the compressor and the fluid of the pressure-controlling
pipe according to signals of the controller.
8. The refrigerating cycle of claim 7, wherein the heat-exchanging
portion comprises a linearly moving mechanism that linearly moves
at least one of the discharging pipe of the compressor and the
pressure-controlling pipe to be spaced apart from each other so
that a distance between the discharging pipe of the compressor and
the pressure-controlling pipe is adjusted according to signals of
the controller.
9. The refrigerating cycle of claim 8, wherein the linearly moving
mechanism comprises a rack coupled to the pressure-controlling
pipe, a pinion engaged with the rack, and a motor that rotates the
pinion according to signals of the controller.
10. The refrigerating cycle of claim 8, wherein the linearly moving
mechanism comprises a magnetic body installed at one of the
pressure-controlling pipe and the discharging pipe of the
compressor, an electromagnet installed at the other one thereof,
and a power supplying portion that applies power to the
electromagnet according to signals of the controller.
11. The refrigerating cycle of claim 7, wherein the heat-exchanging
portion comprises an insulating sheet that linearly makes a
reciprocating motion between the discharging pipe of the compressor
and the pressure-controlling pipe and prevents heat of the
discharging pipe of the compressor from being transferred to the
pressure-controlling pipe, and a linearly moving mechanism that
linearly makes a reciprocating motion of the insulating sheet
according to signals of the controller.
12. The refrigerating cycle of claim 7, wherein the heat-exchanging
portion comprises a heat transfer sheet that linearly makes a
reciprocating motion between the discharging pipe of the compressor
and the pressure-controlling pipe according to signals of the
controller and transfers heat of the discharging pipe of the
compressor to the pressure-controlling pipe, and a linearly moving
mechanism that linearly makes a reciprocating motion of the heat
transfer sheet.
13. The refrigerating cycle of claim 4, wherein the
pressure-controlling portion comprises: a pressure-controlling pipe
which communicates with the variable bladder and in which the fluid
is filled; a refrigerant bypass flow path on which the refrigerant
at the outlet of the compressor is bypassed toward the
pressure-controlling pipe; and a bypass valve that opens/closes the
refrigerant bypass flow path.
14. The refrigerating cycle of claim 7, wherein the
pressure-controlling pipe comprises a capillary flow path.
15. The refrigerating cycle of claim 7, wherein the fluid is used
the same refrigerant on the refrigerant flow path.
16. The refrigerating cycle of claim 7, wherein a volume expansion
coefficient of the fluid filled in the pressure-controlling pipe
and the variable bladder is equal to or greater than a volume
expansion coefficient of the refrigerant.
17. A method for controlling a refrigerating cycle, comprising: a
degree of sub-cooling calculating operation of calculating a degree
of sub-cooling by measuring temperature and pressure of a
refrigerant at an outlet of a condenser; and a volume-controlling
operation of increasing or reducing a volume of a refrigerant
storing portion of a variable volume receiver according to the
calculated degree of sub-cooling by controlling pressure of a fluid
filled in a volume-controlling portion of the variable volume
receiver using heat of the refrigerant at an outlet of a
compressor, wherein the volume-controlling operation comprises: if
the calculated degree of sub-cooling is equal to or greater than a
predetermined degree of sub-cooling, preventing heat of the
refrigerant at the outlet of the compressor from being transferred
to the fluid filled in the volume-controlling portion, thereby
reducing pressure in the volume-controlling portion and increasing
the volume of the refrigerant storing portion; and if the
calculated degree of sub-cooling is less than the predetermined
degree of sub-cooling, increasing pressure in the
volume-controlling portion and reducing the volume of the
refrigerant storing portion when the fluid filled in the
volume-controlling portion receives heat of the refrigerant at the
outlet of the compressor.
18. The refrigerating cycle of claim 13, wherein the
pressure-controlling pipe comprises a capillary flow path.
19. The refrigerating cycle of claim 13, wherein the fluid is used
the same refrigerant on the refrigerant flow path.
20. The refrigerating cycle of claim 13, wherein a volume expansion
coefficient of the fluid filled in the pressure-controlling pipe
and the variable bladder is equal to or greater than a volume
expansion coefficient of the refrigerant.
Description
TECHNICAL FIELD
[0001] The present invention relates to a variable volume receiver
for a refrigerating cycle, a refrigerating cycle including the
variable volume receiver, and a method for controlling the
refrigerating cycle, and more particularly, to a variable volume
receiver for a refrigerating cycle in which a proper degree of
sub-cooling can be secured by changing the volume of a receiver
according to driving conditions, thereby enabling optimum driving,
a refrigerating cycle including the variable volume receiver, and a
method for controlling the refrigerating cycle.
BACKGROUND ART
[0002] In general, driving conditions, such as an outside air
temperature, change in various ways during driving of a
refrigerating cycle. Thus, a proper amount of refrigerant required
for cycle driving also changes. In this regard, a refrigerant
filling amount is determined based on a case where a required
proper amount is large, and when a surplus amount occurs during
driving, the surplus amount is stored in a receiver. In this way,
the receiver serves to cause the cycle to be stably driven in
various conditions. However, a storable space of the receiver is
pre-determined and thus, the receiver is selected to have enough
space.
[0003] Meanwhile, an optimum degree of overheating and an optimum
degree of sub-cooling that may maximize performance in given
conditions respectively exist in the refrigerating cycle. The
degree of overheating can be controlled using an electronic
expansion valve or the like, but the degree of sub-cooling that is
affected by the refrigerant filling amount is not generally
controlled. In particular, in the case of a system to which the
receiver is applied, the degree of sub-cooling cannot be actively
controlled due to enough space of the receiver. Thus, driving in a
state of an optimum degree of sub-cooling in which the performance
of the cycle can be maximized, cannot be guaranteed.
[0004] Meanwhile, in Prior-art patent JP 2550632, the volume of a
refrigerant storing space inside the receiver is increased directly
using a refrigerant that is circulated in the refrigerating cycle.
However, when a refrigerant at a discharging side of a compressor
is used, a control operation for reducing the volume of a variable
capacity body is not smoothly performed, and when a refrigerant at
a suction side of the compressor is used, a control operation for
increasing the volume of the variable capacity body is not smoothly
performed. Since a refrigerant that is circulated in the
refrigerating cycle is directly used, there is a possibility that a
refrigerating capacity will be reduced. Thus, in actuality, there
is a very large limitation in utility.
DETAILED DESCRIPTION OF THE INVENTION
Technical Problem
[0005] The present invention provides a variable volume receiver
for a refrigerating cycle in which the amount of a refrigerant that
may be stored can be controlled according to driving conditions so
that a degree of sub-cooling of a cycle can be actively controlled
and optimum driving can be performed, a refrigerating cycle
including the variable volume receiver, and a method for
controlling the refrigerating cycle
Technical Solution
[0006] According to an aspect of the present invention, there is
provided a variable volume receiver for a refrigerating cycle,
including: a receiver tank that is connected to a refrigerant flow
path and constitutes a refrigerant storing space in which the
refrigerant that passes through the refrigerant flow path is
temporarily stored; a variable bladder that is disposed in the
receiver tank and is contracted or expanded so that a volume of the
refrigerant storing space is reduced or decreased; a
pressure-controlling portion that is installed separately from the
refrigerant flow path, communicates with the variable bladder, is
sealed from an outside and controls pressure in the variable
bladder when a fluid that communicates with the variable bladder
and is filled in the variable bladder receives heat of the
refrigerant at an outlet of a compressor in the refrigerating
cycle; and a controller that controls the pressure-controlling
portion according to driving conditions, changes the volume of the
refrigerant storing space and controls an amount of the refrigerant
that is capable of being stored in the refrigerant storing
space.
[0007] According to another aspect of the present invention, there
is provided a variable volume receiver for a refrigerating cycle,
including: a receiver tank that is connected to a refrigerant flow
path and constitutes a refrigerant storing space in which the
refrigerant that passes through the refrigerant flow path is
temporarily stored; a piston that is coupled to the receiver tank
so as to linearly make a reciprocating motion and increases or
reduces a volume of the refrigerant storing space while linearly
making a reciprocating motion; a linearly moving mechanism that
linearly makes a reciprocating motion of the piston; and a
controller that controls the linearly moving mechanism according to
driving conditions, changes the volume of the refrigerant storing
space and controls an amount of the refrigerant that is capable of
being stored in the refrigerant storing space.
[0008] According to still another aspect of the present invention,
there is provided a refrigerating cycle including a compressor, a
condenser, an expansion mechanism, an evaporator, and a controller,
further including a variable volume receiver, wherein the variable
volume receiver includes a refrigerant storing portion which is
installed on a refrigerant flow path that connects the condenser
and the expansion mechanism and in which a refrigerant discharged
from the condenser is temporarily stored, and a volume-controlling
portion controls a volume of the refrigerant storing portion while
being contracted or expanded by a pressure-controlling portion that
is installed separately from the refrigerant flow path and sealed
from an outside, and the controller controls pressure of a fluid in
the volume-controlling portion according to driving conditions,
changes the volume of the refrigerant storing portion and controls
an amount of the refrigerant stored in the variable volume
receiver.
[0009] According to still another aspect of the present invention,
there is provided a refrigerating cycle including a compressor, a
condenser, an expansion mechanism, an evaporator, and a controller,
further including a variable volume receiver, wherein the variable
volume receiver includes a receiver tank that is installed on a
refrigerant flow path that connects the condenser and the expansion
mechanism and constitutes a refrigerant storing space in which a
refrigerant discharged from the condenser is temporarily stored, a
variable bladder that is disposed in the receiver tank and reduces
or increases a volume of the refrigerant storing space while being
contracted or expanded, and a pressure-controlling portion that is
installed separately from the refrigerant flow path, communicates
with the variable bladder, is sealed from an outside and controls
pressure in the variable bladder when a fluid filled in the
variable bladder receives heat of the refrigerant at an outlet of
the compressor, and the controller calculates a degree of
sub-cooling according to temperature and pressure of the
refrigerant at an outlet of the condenser and controls the
pressure-controlling portion according to the calculated degree of
sub-cooling.
[0010] According to still another aspect of the present invention,
there is provided a refrigerating cycle including a compressor, a
condenser, an expansion mechanism, an evaporator, and a controller,
further including a variable volume receiver, wherein the variable
volume receiver includes a receiver tank that is connected to a
refrigerant flow path and constitutes a refrigerant storing space
in which a refrigerant that passes through the refrigerant flow
path is temporarily stored, a piston that is coupled to the
receiver tank so as to linearly make a reciprocating motion and
increases or reduces a volume of the refrigerant storing space
while linearly making a reciprocating motion, and a linearly moving
mechanism that linearly makes a reciprocating motion of the piston,
and the controller calculates a degree of sub-cooling according to
temperature and pressure of the refrigerant at an outlet of the
condenser and controls the linearly moving mechanism according to
the calculated degree of sub-cooling.
[0011] According to still another aspect of the present invention,
there is provided a method for controlling a refrigerating cycle,
including: a degree of sub-cooling calculating operation of
calculating a degree of sub-cooling by measuring temperature and
pressure of a refrigerant at an outlet of a condenser; and a
volume-controlling operation of increasing or reducing a volume of
a refrigerant storing portion of a variable volume receiver
according to the calculated degree of sub-cooling by controlling
pressure of a fluid filled in a volume-controlling portion of the
variable volume receiver using heat of the refrigerant at an outlet
of a compressor, wherein the volume-controlling operation includes:
if the calculated degree of sub-cooling is equal to or greater than
a predetermined degree of sub-cooling, preventing heat of the
refrigerant at the outlet of the compressor from being transferred
to the fluid filled in the volume-controlling portion, thereby
reducing pressure in the volume-controlling portion and increasing
the volume of the refrigerant storing portion; and if the
calculated degree of sub-cooling is less than the predetermined
degree of sub-cooling, increasing pressure in the
volume-controlling portion and reducing the volume of the
refrigerant storing portion when the fluid filled in the
volume-controlling portion receives heat of the refrigerant at the
outlet of the compressor.
Effects of the Invention
[0012] A variable volume receiver for a refrigerating cycle
according to the present invention can control the capacity for
storing a refrigerant according to changes in driving conditions,
such as an outside air temperature or a load-side temperature, and
can secure a proper degree of sub-cooling even when the driving
conditions change, thereby enabling optimum driving regardless of
changes in the outside air temperature or the load-side
temperature.
[0013] In addition, the variable volume receiver for the
refrigerating cycle according to the present invention is
configured to expand a variable bladder by increasing a fluid
pressure in a pressure-controlling pipe using heat of a
high-temperature refrigerant discharged from a compressor. Thus, an
additional heat source or mechanism for increasing the fluid
pressure in the pressure-controlling pipe is not required.
[0014] Furthermore, the variable volume receiver for the
refrigerating cycle according to the present invention uses an
additional fluid without using the refrigerant that is circulated
in the refrigerating cycle when the variable bladder is contracted
or expanded, so that all amounts of the refrigerant discharged from
the compressor can be introduced into a condenser without any
loss.
DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a view of a state in which the volume of a
refrigerant storing portion is increased, in a refrigerating cycle
according to a first embodiment of the present invention;
[0016] FIG. 2 is a view of a state in which the volume of the
refrigerant storing portion is reduced, in the refrigerating cycle
illustrated in FIG. 1;
[0017] FIG. 3 is a view of an operation of a heat-exchanging
portion illustrated in FIGS. 1 and 2;
[0018] FIG. 4 is a control block diagram of the refrigerating cycle
illustrated in FIG. 1;
[0019] FIG. 5 is a control flowchart of the refrigerating cycle
illustrated in FIG. 1;
[0020] FIG. 6 is a view of an operation of a heat-exchanging
portion according to a second embodiment of the present
invention;
[0021] FIG. 7 is a view of a state in which the volume of the
refrigerant storing portion is increased, in a refrigerating cycle
according to a third embodiment of the present invention;
[0022] FIG. 8 is a view of a state in which the volume of the
refrigerant storing portion is reduced, in the refrigerating cycle
illustrated in FIG. 7;
[0023] FIG. 9 is a control block diagram of the refrigerating cycle
illustrated in FIG. 7;
[0024] FIG. 10 is a modified example of a variable volume receiver
illustrated in FIG. 7;
[0025] FIG. 11 is a view of a state in which the volume of the
refrigerant storing portion is reduced, in a refrigerating cycle
according to a fifth embodiment of the present invention; and
[0026] FIG. 12 is a view of a state in which the volume of the
refrigerant storing portion is increased, in the refrigerating
cycle illustrated in FIG. 11.
MODE OF THE INVENTION
[0027] Hereinafter, a refrigerating cycle including a variable
volume receiver according to embodiments of the present invention
will be described.
[0028] FIG. 1 is a view of a state in which the volume of a
refrigerant storing portion is increased, in a refrigerating cycle
according to a first embodiment of the present invention. FIG. 2 is
a view of a state in which the volume of the refrigerant storing
portion is reduced, in the refrigerating cycle illustrated in FIG.
1. FIG. 3 is a view of an operation of a heat-exchanging portion
illustrated in FIGS. 1 and 2. FIG. 4 is a control block diagram of
the refrigerating cycle illustrated in FIG. 1.
[0029] Referring to FIGS. 1 and 2, the refrigerating cycle
according to the first embodiment of the present invention includes
a compressor 2, a condenser 4, a variable volume receiver 10, an
expansion valve 8, and an evaporator 6.
[0030] The variable volume receiver 10 is installed on a
refrigerant flow path that connects the condenser 4 and the
expansion valve 8. The variable volume receiver 10 includes a
receiver tank that constitutes a refrigerant storing portion 12 in
which a refrigerant at an outlet of the condenser 4 is temporarily
stored, a variable bladder 14 that is disposed in the receiver tank
and is contracted or expanded, and a pressure-controlling portion
that controls a pressure of a fluid filled in the
pressure-controlling pipe 20 that will be described later, so as to
contract or expand the variable bladder 14.
[0031] The receiver tank is connected to the refrigerant flow path,
temporarily stores a liquid refrigerant discharged from the
condenser 4 and then sends the liquid refrigerant to the expansion
valve 8.
[0032] A bladder that is a synthetic rubber bag having good
elasticity is used as the variable bladder 14, and the variable
bladder 14 is connected to the pressure-controlling pipe 20. The
variable bladder 14 is expanded when the pressure of the fluid in
the pressure-controlling pipe 20 is increased, and is contracted
when the pressure of the fluid in the pressure-controlling pipe 20
is decreased. When the variable bladder 14 is contracted, a portion
of the variable bladder 14 in the receiver tank is reduced so that
the volume of the refrigerant storing portion 12 is increased. When
the variable bladder 14 is expanded, the portion of the variable
bladder 14 in the receiver tank is increased so that the volume of
the refrigerant storing portion 12 is reduced.
[0033] The pressure-controlling portion is installed separately
from the refrigerant flow path. The pressure-controlling portion
communicates with the variable bladder 14 and is sealed from the
outside. The pressure-controlling portion controls a pressure of
the variable bladder 14 when the fluid filled in the
pressure-controlling portion receives heat of the refrigerant at an
outlet of the compressor 2, is evaporated and expanded. The
pressure-controlling portion includes a heat-exchanging portion 40
installed at a discharge side of the compressor 2 and the
pressure-controlling pipe 20 that transfers the pressure of the
fluid in a heat-exchanging pipe 21 that will be described later to
the variable bladder 14. The same refrigerant as the refrigerant
that is circulated in the refrigerating cycle may also be used as
the fluid, and a fluid having a larger volume expansion coefficient
than that of the refrigerant may also be used as the fluid. When
the volume expansion coefficient of the fluid is large, contraction
or expansion of the fluid is well performed by heat exchanging so
that contraction or expansion of the variable bladder 14 in which
the fluid is filled, can also be well performed.
[0034] The heat-exchanging portion 40 includes a discharging pipe
41 of the compressor 2, the pressure-controlling pipe 20, and a
linearly moving mechanism. Heat-exchanging between the discharging
pipe 41 and the pressure-controlling pipe 20 is performed by the
heat-exchanging portion 40.
[0035] The discharging pipe 41 of the compressor 2 is provided to
pass through the heat-exchanging portion 40. The refrigerant that
is compressed by the compressor 2 at a high temperature under a
high pressure passes through the discharging pipe 41 of the
compressor 2.
[0036] The pressure-controlling pipe 20 includes the
heat-exchanging pipe 21 and a capillary tube 22. All sections of
the pressure-controlling pipe 20 are configured of the capillary
tube 22 except for a portion of the pressure-controlling pipe 20
connected to the discharging portion 41 of the compressor 2 and a
portion that communicates with the variable bladder 14. The
capillary tube 22 accelerates a pressure transfer speed, and an
inside of the pressure-controlling pipe 20 is in a two-phase state,
i.e., in a state in which both a liquid fluid and a vapor fluid
exist. The liquid fluid is concentrated on the heat-exchanging pipe
21. When the liquid fluid is in contact with the discharging pipe
41, the liquid fluid is evaporated and expanded by receiving heat
of the high-temperature refrigerant that flows in the discharging
pipe 41.
[0037] The linearly moving mechanism adjusts a distance between the
heat-exchanging pipe 21 and the discharging pipe 41 of the
compressor 2. The linearly moving mechanism linearly moves the
heat-exchanging pipe 21 to be in contact with or spaced apart from
the discharging pipe 41 of the compressor 2. The linearly moving
mechanism includes a rack 24 coupled to the heat-exchanging pipe
21, a pinion 26 engaged with the rack 24, and a motor 28 that
rotates the pinion 26. The rack 24 is coupled to one side of the
heat-exchanging pipe 21 and linearly moves when the pinion 26 is
rotated by driving the motor 28.
[0038] In this way, in the present embodiment, the rack 24 is
coupled to the heat-exchanging pipe 21. However, embodiments of the
present invention are not limited thereto, and the pinion 26 may
also be coupled to the heat-exchanging pipe 21. Also, in the
present embodiment, the position of the discharging pipe 41 is
fixed, and the heat-exchanging pipe 21 is linearly moved. However,
embodiments of the present invention are not limited thereto, and
the position of the heat-exchanging pipe 21 may be fixed, and the
discharging pipe 41 may be linearly moved, or both the
heat-exchanging pipe 21 and the discharging pipe 41 may be linearly
moved.
[0039] A motor that may be bidirectionally rotated is used as the
motor 28, and a rotation direction of the motor 28 changes
according to signals of a controller 60.
[0040] The refrigerating cycle further includes a temperature
sensor 31 that measures temperature T of the refrigerant at an
outlet of the condenser 4 and a pressure sensor 32 that measures
pressure P of the refrigerant at the outlet of the condenser 4.
[0041] The controller 60 calculates a degree of sub-cooling
according to values detected by the temperature sensor 31 and the
pressure sensor 32, compares the calculated degree of sub-cooling
with a predetermined range of sub-cooling and controls an operation
of the motor 28 according to the result of comparison. In the
present embodiment, the controller 60 controls the operation of the
motor 28 according to the degree of sub-cooling. However,
embodiments of the present invention are not limited thereto, and
the controller 60 may control the operation of the motor 28
according to an outside air temperature or other driving
conditions, thereby adjusting the volume of the variable volume
receiver 10.
[0042] A method for controlling the refrigerating cycle having the
above configuration according to a first embodiment of the present
invention will be described as below.
[0043] Referring to FIG. 5, the temperature T and the pressure P of
the refrigerant at the outlet of the condenser 4 are measured (S1).
The temperature sensor 31 measures the temperature T of the
refrigerant at the outlet of the condenser 4, and the pressure
sensor 32 measures the pressure P of the refrigerant at the outlet
of the condenser 4. A saturation temperature Tsat can be known from
the pressure P of the refrigerant measured by the pressure sensor
32 (S2).
[0044] By calculating a difference between the saturation
temperature Tsat of the refrigerant and the measured temperature T,
a degree of sub-cooling can be calculated (S3). It is compared
whether a value of the calculated degree of sub-cooling is equal to
a value of a predetermined degree of sub-cooling (S4). If the two
values are different from each other, the pressure-controlling
portion is controlled so that the variable bladder 14 is contracted
or expanded and thus, the volume of the refrigerant storing portion
12 is reduced or increased (S5). Changes in the volume of the
refrigerant storing portion 12 change a substantial filling amount
of a cycle defined as the sum of the compressor 2, the condenser 4,
the expansion valve 8, the evaporator 6, and the amount of the
refrigerant filled in a connection pipe thereof, except for the
amount of the refrigerant stored in the variable volume receiver
10. This finally causes changes in the degree of sub-cooling and
thus, the degree of sub-cooling can be controlled by controlling
the pressure-controlling portion.
[0045] In this case, if the calculated degree of sub-cooling is
equal to or greater than the predetermined degree of sub-cooling,
it is determined that the substantial filling amount is larger than
an optimum filling amount. Thus, the volume of the variable bladder
14 in the variable volume receiver 10 is reduced, and the amount of
the refrigerant stored in the refrigerant storing portion 12 is
increased by increasing the volume of the refrigerant storing
portion 12.
[0046] Referring to FIGS. 2 and 3(a), in order to reduce the volume
of the variable bladder 14, the discharging pipe 41 of the
compressor 2 and the heat-exchanging pipe 21 are spaced apart from
each other so that heat-exchanging is not performed by the
heat-exchanging portion 40. When the motor 28 is rotated clockwise,
the rack 24 moves backward, and the heat-exchanging pipe 21 is
spaced apart from the discharging pipe 41. When the heat-exchanging
pipe 21 and the discharging pipe 41 are spaced apart from each
other, the fluid in the heat-exchanging pipe 21 does not receive
heat from the discharging pipe 41, and the fluid in the
pressure-controlling pipe 20 is maintained in a room temperature
state. Since the fluid in the room temperature state is a two-phase
fluid in which a liquid phase and a vapor phase are mixed with each
other and has a lower pressure than that of the refrigerant at the
outlet of the condenser 4, a pressure in the variable bladder 14 is
reduced, and the variable bladder 14 is contracted. When the
variable bladder 14 is contracted, the volume of the refrigerant
storing portion 12 is relatively increased. Thus, the amount of the
refrigerant that may be stored in the variable volume receiver 10
is increased. When the amount of the refrigerant stored in the
variable volume receiver 10 is increased, the substantial filling
amount in the refrigerating cycle is reduced, and the amount of the
refrigerant in the condenser 4 is also reduced. Thus, the degree of
sub-cooling of the refrigerant is reduced and is adjusted in the
range of the predetermined degree of sub-cooling.
[0047] Meanwhile, when the calculated degree of sub-cooling is less
than the predetermined degree of sub-cooling, it is determined that
the substantial filling amount in the refrigerating cycle should be
increased. Thus, the volume of the variable bladder 14 in the
variable volume receiver 10 is increased, and the volume of the
refrigerant storing portion 12 is reduced so that the amount of the
refrigerant stored in the refrigerant storing portion 12 can be
reduced.
[0048] Referring to FIGS. 1 and 3(b), in order to increase the
volume of the variable bladder 14, the discharging pipe 41 of the
compressor 2 and the heat-exchanging pipe 21 are in contact with
each other so that heat-exchanging is performed by the
heat-exchanging portion 40. When the motor 28 is rotated
counterclockwise, the rack 24 moves forward, and the
heat-exchanging pipe 21 moves forward toward the discharging pipe
41 and thus is in contact with the discharging pipe 41. When the
heat-exchanging pipe 21 and the discharging pipe 41 are in contact
with each other, the fluid in the heat-exchanging pipe 21 receives
heat from the high-temperature refrigerant that passes through the
discharging pipe 41. Due to heat transferred from the discharging
pipe 41, a temperature of the fluid in the pressure-controlling
pipe 20 rises, and the liquid fluid is evaporated so that a
proportion of the vapor fluid in the entire fluid is increased.
Thus, temperature and pressure in the pressure-controlling pipe 20
are increased, and the pressure in the variable bladder 14 is
increased so that the variable bladder 14 is expanded. When the
variable bladder 14 is expanded and its volume is increased, the
volume of the refrigerant storing portion 12 is relatively reduced.
The volume of the refrigerant storing portion 12 is reduced and the
amount of the refrigerant that may be stored in the variable volume
receiver 10 is reduced, the substantial filling amount is
increased, and the amount of the refrigerant in the condenser 4 is
increased so that the degree of sub-cooling of the refrigerant is
increased.
[0049] As described above, the volume of the variable bladder 14 is
contracted or expanded so that the volume of the refrigerant
storing portion 12 can be reduced or increased. Thus, the degree of
sub-cooling of the refrigerant can be adjusted in a predetermined
range.
[0050] FIG. 6 is a view of an operation of a heat-exchanging
portion according to a second embodiment of the present
invention.
[0051] Referring to FIG. 6, the heat-exchanging portion according
to the second embodiment of the present invention is different from
the heat-exchanging portion according to the first embodiment in
that a sheet 50 that linearly makes a reciprocating motion between
the discharging pipe 41 of the compressor 2 and the heat-exchanging
pipe 21 is installed. The difference will be described in
detail.
[0052] The sheet 50 may be an insulating sheet that insulates a
space between the discharging pipe 41 and the heat-exchanging pipe
21 or a heat transfer sheet that transfers heat of the discharging
pipe 41 to the heat-exchanging pipe 21. In the present embodiment,
the sheet 50 is the insulating sheet that insulates the space
between the discharging pipe 41 and the heat-exchanging pipe
21.
[0053] The heat-exchanging portion further includes a linearly
moving mechanism that linearly makes a reciprocating motion of the
sheet 50 between the discharging pipe 41 and the heat-exchanging
pipe 21. The linearly moving mechanism includes a rack 51 that is
formed integrally with the sheet 50 or coupled to the sheet 50, a
pinion 42 engaged with the rack 51, and a motor 53 that rotates the
pinion 42. However, embodiments of the present invention are not
limited thereto, and of course, the pinion 42 may be coupled to the
rack 51.
[0054] When the discharging pipe 41 and the heat-exchanging pipe 21
are heat-exchanged, the heat-exchanging portion having the above
configuration rotates the motor 53 counterclockwise and moves the
sheet 50 downward, as illustrated in FIG. 6(b). The heat-exchanging
pipe 21 is provided to have elasticity in a direction of the
discharging pipe 41 so that the heat-exchanging pipe 21 and the
discharging pipe 41 are in contact with each other and thus
heat-exchanging is performed. The fluid in the heat-exchanging pipe
21 receives heat from the discharging pipe 41 and is evaporated and
expanded, thereby expanding the variable bladder 14.
[0055] Meanwhile, when the discharging pipe 41 and the
heat-exchanging pipe 21 are not heat-exchanged, as illustrated in
FIG. 6(b), the motor 53 is rotated clockwise. When the motor 53 is
rotated clockwise, the sheet 50 is moved upward and is inserted
into a space between the discharging pipe 41 and the
heat-exchanging pipe 21 so that heat of the discharging pipe 41 can
be prevented from being transferred to the heat-exchanging pipe 21.
When heat is not transferred to the heat-exchanging pipe 21, the
fluid in the heat-exchanging pipe 21 is cooled and contracted so
that the variable bladder 14 is also contracted.
[0056] FIG. 7 is a view of a state in which the volume of the
refrigerant storing portion is increased, in a refrigerating cycle
according to a third embodiment of the present invention. FIG. 8 is
a view of a state in which the volume of the refrigerant storing
portion is reduced, in the refrigerating cycle illustrated in FIG.
7. FIG. 9 is a control block diagram of the refrigerating cycle
illustrated in FIG. 7.
[0057] Referring to FIGS. 7 and 8, the refrigerating cycle
according to the third embodiment of the present invention further
includes a refrigerant bypass flow path 110, a bypass valve 112, a
heat-exchanging portion 100, and a pressure-controlling pipe
20.
[0058] On the bypass flow path 110, the refrigerant discharged from
the discharging pipe of the compressor 2 is bypassed toward the
heat-exchanging portion 100. A check valve 116 is installed at an
outlet of the bypass flow path 110.
[0059] The bypass valve 112 is a valve that opens/closes the bypass
flow path 110 according to signals of a controller 120.
[0060] A flow rate regulating valve 114 that opens/closes a flow
path is installed at the discharging pipe of the compressor 2.
[0061] The heat-exchanging portion 100 performs heat-exchanging
between the refrigerant bypassed on the bypass flow path 110 and
the heat-exchanging pipe 21 of the pressure-controlling pipe
20.
[0062] The controller 120 calculates a degree of sub-cooling
according to the temperature and pressure detected by the
temperature sensor 31 and the pressure sensor 32, compares the
calculated degree of sub-cooling with a predetermined degree of
sub-cooling and controls the bypass valve 112 and the flow rate
regulating valve 114 according to the result of comparison.
[0063] A difference between the method for controlling the
refrigerating cycle having the above configuration according to the
third embodiment of the present invention and that according to the
first embodiment of the present invention will be described.
[0064] First, when the calculated degree of sub-cooling is equal to
or greater than the predetermined degree of sub-cooling according
to the temperature and pressure detected by the temperature sensor
31 and the pressure sensor 32, it is determined that the
substantial filling amount in the cycle is larger than an optimum
filling amount, and the volume of the refrigerant storing portion
12 of the variable volume receiver 10 is increased.
[0065] The controller 120 closes the bypass valve 112 and opens the
flow rate regulating valve 114 so that the refrigerant discharged
from the compressor 2 is not bypassed on the bypass flow path 110.
Thus, since heat of the high-temperature refrigerant discharged
from the compressor 2 is not transferred to the fluid in the
heat-exchanging pipe 21, the fluid in the pressure-controlling pipe
20 is maintained in a room temperature state. Since the fluid in
the room temperature state is a two-phase fluid in which a liquid
phase and a vapor phase are mixed with each other and has a lower
pressure than that of the refrigerant at the outlet of the
condenser, pressure in the variable bladder 14 is also reduced, and
the variable bladder 14 is contracted. When the variable bladder 14
is contracted, the volume of the refrigerant storing portion 12 is
relatively increased. Thus, the amount of the refrigerant that may
be stored in the variable volume receiver 10 is increased. When the
amount of the refrigerant stored in the variable volume receiver 10
is increased, the substantial filling amount in the refrigerating
cycle is reduced, and the amount of the refrigerant in the
condenser 4 is also reduced. Thus, the degree of sub-cooling of the
refrigerant is reduced.
[0066] Thus, when the calculated degree of sub-cooling is higher
than the predetermined degree of sub-cooling, the degree of
sub-cooling of the refrigerant may be reduced and adjusted to the
predetermined degree of sub-cooling.
[0067] Meanwhile, when the calculated degree of sub-cooling is less
than the predetermined degree of sub-cooling, it is determined that
the substantial filling amount is insufficient compared to the
optimum filling amount, and the volume of the refrigerant storing
portion 12 of the variable volume receiver 10 is reduced.
[0068] The controller 120 opens the bypass valve 112 and closes the
flow rate regulating valve 114. The refrigerant discharged from the
compressor 2 is bypassed on the bypass flow path 110, and heat of
the high-temperature refrigerant discharged from the compressor 2
is transferred to the fluid. Due to heat transferred from the
discharging pipe 41, temperature of the fluid in the
pressure-controlling pipe 20 is increased, and a proportion of the
vapor fluid in the entire fluid is increased when the liquid fluid
is evaporated. Thus, the temperature and pressure in the
pressure-controlling pipe 20 are increased, and the pressure in the
variable bladder 14 is also increased so that the variable bladder
14 is expanded. When the variable bladder 14 is expanded and the
volume of the variable bladder 14 is increased, the volume of the
refrigerant storing portion 12 is relatively reduced. When the
volume of the refrigerant storing portion 12 is reduced and the
amount of the refrigerant that may be stored in the variable volume
receiver 10 is reduced, the substantial filling amount is
increased, and the amount of the refrigerant in the condenser 4 is
increased, and the degree of sub-cooling of the refrigerant is
increased.
[0069] Thus, when the calculated degree of sub-cooling is less than
the predetermined degree of sub-cooling, the degree of sub-cooling
of the refrigerant may be increased and adjusted to the
predetermined degree of sub-cooling, as described above.
[0070] Meanwhile, as illustrated in FIG. 10, a variable bladder
type accumulator 150 may be used as the variable volume receiver.
The variable bladder type accumulator has a structure in which a
variable bladder 153 that is a synthetic rubber bag is installed at
an upper side of an inside of a pressure tank 151 and a fluid in
the pressure tank 151 and a fluid in the variable bladder 153 are
spaced apart from each other. When the variable bladder 153 is
contracted or expanded, the volume of an internal space 152 of the
pressure tank is increased or reduced.
[0071] Meanwhile, a linearly moving mechanism of a variable volume
receiver according to a fourth embodiment of the present invention
is different from that according to the third embodiment of the
present invention in that the linearly moving mechanism of the
fourth embodiment of the present invention includes a magnetic body
(not shown) installed at one of the pressure-controlling pipe 20
and the discharging pipe 41 of the compressor 2, an electromagnet
(not shown) installed at the other one thereof and a power
supplying portion that applies power to the electromagnet (not
shown) according to signals of the controller 120. Thus, the
controller 120 applies or blocks power to or from the electromagnet
(not shown), thereby adjusting a distance between the
pressure-controlling pipe 20 and the discharging pipe 41 of the
compressor 2 so that the pressure of the fluid in the
pressure-controlling pipe 20 can be increased or reduced using heat
of the discharging pipe 41 of the compressor 2.
[0072] FIG. 11 is a view of a state in which the volume of the
refrigerant storing portion is reduced, in a refrigerating cycle
according to a fifth embodiment of the present invention. FIG. 12
is a view of a state in which the volume of the refrigerant storing
portion is increased, in the refrigerating cycle illustrated in
FIG. 11.
[0073] Referring to FIGS. 11 and 12, a variable volume receiver 200
for a refrigerating cycle according to the fifth embodiment of the
present invention includes a receiver tank in which a refrigerant
storing portion 201 is formed, a piston 210, and a linearly moving
mechanism.
[0074] The piston 210 is coupled to the receiver tank so as to
linearly make a reciprocating motion, linearly makes a
reciprocating motion and increases or reduces the volume of the
refrigerant storing portion 201. A sealing member that prevents
leakage of the refrigerant stored in the refrigerant storing
portion 201 is installed between the piston 210 and the receiver
tank.
[0075] The linearly moving mechanism linearly moves the piston 210.
The linearly moving mechanism includes a rack 211 that is formed
integrally with or couple to a rod of the piston 210, a pinion 212
engaged with the rack 211, and a motor 213 that rotates the pinion
212.
[0076] A difference between a method for controlling the
refrigerating cycle having the above configuration and the method
according to the first embodiment will be described.
[0077] First, when a calculated degree of sub-cooling is less than
a predetermined degree of sub-cooling according to the temperature
and pressure detected by the temperature sensor 31 and the pressure
sensor 32, it is determined that the substantial filling amount is
insufficient compared to an optimum filling amount, and the volume
of the refrigerant storing portion 201 of the variable volume
receiver 200 is reduced.
[0078] Referring to FIG. 11, when the pinion 212 is rotated
clockwise, the rack 211 moves downward, and the piston 210 reduces
the volume of the refrigerant storing portion 201. When the volume
of the refrigerant storing portion 201 is reduced, the amount of
the refrigerant that may be stored in the refrigerant storing
portion 201 is reduced. When the amount of the refrigerant that may
be stored in the refrigerant storing portion 201 is reduced, the
substantial filling amount is increased, and the amount of the
refrigerant in the condenser 4 is increased so that the degree of
sub-cooling of the refrigerant is increased.
[0079] Thus, when the calculated degree of sub-cooling is less than
the predetermined degree of sub-cooling, the degree of sub-cooling
of the refrigerant may be increased and adjusted to the
predetermined degree of sub-cooling, as described above.
[0080] Meanwhile, when the calculated degree of sub-cooling is
equal to or greater than the predetermined degree of sub-cooling,
it is determined that the substantial filling amount is larger than
the optimum filling amount, and the volume of the refrigerant
storing portion 201 of the variable volume receiver 200 is
increased.
[0081] Referring to FIG. 12, when the pinion 212 is rotated
counterclockwise, the rack 211 moves upward, and the piston 211
moves upward so that the volume of the refrigerant storing portion
201 is increased. When the volume of the refrigerant storing
portion 201 is increased, the amount of the refrigerant that may be
stored in the refrigerant storing portion 201 is increased. When
the amount of the refrigerant that may be stored in the refrigerant
storing portion 201 is increased, the substantial filling amount is
reduced, and the amount of the refrigerant in the condenser 4 is
reduced. Thus, the degree of sub-cooling of the refrigerant is
reduced.
[0082] Thus, when the calculated degree of sub-cooling is higher
than the predetermined degree of sub-cooling, the degree of
sub-cooling of the refrigerant may be reduced and adjusted to the
predetermined degree of sub-cooling, as described above.
[0083] While the present invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by those of ordinary skill in the art that various
changes in form and details may be made therein without departing
from the spirit and scope of the present invention as defined by
the following claims.
INDUSTRIAL APPLICABILITY
[0084] According to the present invention, a variable volume
receiver for a refrigerating cycle that enables optimum driving and
the refrigerating cycle including the same can be manufactured.
* * * * *