U.S. patent application number 13/128533 was filed with the patent office on 2012-02-16 for expansion valve comprising biasing means.
Invention is credited to Claus Thybo.
Application Number | 20120036885 13/128533 |
Document ID | / |
Family ID | 41785698 |
Filed Date | 2012-02-16 |
United States Patent
Application |
20120036885 |
Kind Code |
A1 |
Thybo; Claus |
February 16, 2012 |
EXPANSION VALVE COMPRISING BIASING MEANS
Abstract
An expansion valve (1) comprising an inlet opening adapted to
receive fluid medium in a liquid state and at least two outlet
openings (8), each being adapted to deliver fluid medium in an at
least partly gaseous state, is disclosed, e.g. for use in a
refrigeration system. The expansion valve (1) further comprises a
first valve part (2) having at least two valve seats (3) formed
therein, each of the valve seats (3) being fluidly connected to one
of the outlet openings (8), a second valve part (4), the first
valve part (2) and the second valve part (4) being arranged movably
relative to each other, and at least two valve elements (5), each
valve element (5) being arranged in such a manner that the valve
seats (3) and the valve elements (5) pair-wise form at least two
valves. Biasing means, e.g. in the form of springs (6), are
arranged to bias the valve elements (5) and the valve seats (3)
towards a position defining a minimum opening degree of the valves,
or towards a position defining a maximum opening degree of the
valves, and the second valve part (4) and the valve elements (5)
are connected in such a manner that the mutual position of the
first valve part (2) and the second valve part (4) determines an
opening degree of each of the valves. The biasing means defines a
point of equilibrium for the relative movements of the valve seats
(3) and the valve elements (5).
Inventors: |
Thybo; Claus; (Soenderborg,
DK) |
Family ID: |
41785698 |
Appl. No.: |
13/128533 |
Filed: |
November 11, 2009 |
PCT Filed: |
November 11, 2009 |
PCT NO: |
PCT/DK09/00234 |
371 Date: |
July 8, 2011 |
Current U.S.
Class: |
62/498 ;
236/99R |
Current CPC
Class: |
F25B 41/385 20210101;
F25B 41/39 20210101; F25B 39/028 20130101; F25B 41/31 20210101 |
Class at
Publication: |
62/498 ;
236/99.R |
International
Class: |
F25B 1/00 20060101
F25B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2008 |
DK |
PA 2008 01568 |
Claims
1. An expansion valve comprising: an inlet opening adapted to
receive fluid medium in a liquid state, at least two outlet
openings, each being adapted to deliver fluid medium in an at least
partly gaseous state, a first valve part having at least two valve
seats formed therein, each of the valve seats being fluidly
connected to one of the outlet openings, a second valve part, the
first valve part and the second valve part being arranged movably
relative to each other, at least two valve elements, each valve
element being arranged in such a manner that the valve seats and
the valve elements pair-wise form at least two valves, and biasing
means arranged to bias the valve elements and the valve seats
towards a position defining a minimum opening degree of the valves,
or towards a position defining a maximum opening degree of the
valves, wherein the second valve part and the valve elements are
connected in such a manner that the mutual position of the first
valve part and the second valve part determines an opening degree
of each of the valves.
2. The expansion valve according to claim 1, wherein the valve
elements form part of the second valve part.
3. The expansion valve according to claim 1, wherein the valve
elements form separate parts being operatively connected to the
second valve part.
4. The expansion valve according to claim 1, wherein the biasing
means is or comprises at least one spring.
5. The expansion valve according to claim 1, wherein the valve
elements are of a needle type.
6. The expansion valve according to claim 1, wherein the valve
elements are of a ball type.
7. The expansion valve according to claim 1, further comprising a
thermostatic element, wherein the first valve part and/or the
second valve part is/are operatively connected to the thermostatic
element, relative movements of the first valve part and the second
valve part thereby being caused by the thermostatic element.
8. The expansion valve according to claim 7, wherein the biasing
means is arranged to counteract movements caused by the
thermostatic element in response to an increase in pressure.
9. A refrigeration system comprising: at least one compressor, at
least one condenser, at least two evaporators arranged in parallel
along a refrigerant flow path of the refrigeration system, and an
expansion valve according to claim 1, said expansion valve being
arranged in such a manner that each of the valves is arranged to
deliver refrigerant to one of the evaporators.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is entitled to the benefit of and
incorporates by reference essential subject matter disclosed in
International Patent Application No. PCT/DK2009/000234 filed on
Nov. 11, 2009 and Danish Patent Application No. PA 2008 01568 filed
Nov. 12, 2008.
FIELD OF THE INVENTION
[0002] The present invention relates to an expansion valve, in
particular for use in a refrigeration system, e.g. an air condition
system. The expansion valve of the present invention is adapted to
distribute fluid medium to at least two parallel flow paths, e.g.
in the form of at least two parallel evaporators or evaporator
tubes.
BACKGROUND OF THE INVENTION
[0003] In a fluid circuit, such as a refrigerant circuit of a
refrigeration system, it is sometimes desirable to split the flow
path into two or more parallel flow paths along part of the fluid
circuit. This is, e.g., the case in refrigeration systems
comprising two or more evaporators arranged in parallel. It may
further be desirable to be able to control the fluid flow to each
of the parallel flow paths, e.g. in such a manner that a
substantially equal fluid distribution is obtained, or in such a
manner that the system is operated in an optimum manner, e.g. in
terms of energy consumption or efficiency.
[0004] In some previous attempts to control distribution of
refrigerant between two or more parallel flow paths in a
refrigeration system, a distributor is arranged downstream relative
to an expansion valve in the refrigerant flow path. Thus, the
refrigerant is distributed after expansion of the refrigerant, i.e.
the refrigerant is mainly gaseous. This has the disadvantage that
it is very difficult to control the flow of refrigerant to obtain a
substantially equal distribution between the parallel flow
paths.
SUMMARY OF THE INVENTION
[0005] It is an object of embodiments of the invention to provide
an expansion valve which is capable of controlling distribution of
fluid to two or more parallel flow paths.
[0006] It is a further object of embodiments of the invention to
provide an expansion valve which is adapted to manage distribution
of fluid to two or more parallel flow paths in an easy manner.
[0007] According to a first aspect the present invention provides
an expansion valve comprising: [0008] an inlet opening adapted to
receive fluid medium in a liquid state, [0009] at least two outlet
openings, each being adapted to deliver fluid medium in an at least
partly gaseous state, [0010] a first valve part having at least two
valve seats formed therein, each of the valve seats being fluidly
connected to one of the outlet openings, [0011] a second valve
part, the first valve part and the second valve part being arranged
movably relative to each other, [0012] at least two valve elements,
each valve element being arranged in such a manner that the valve
seats and the valve elements pair-wise form at least two valves,
and [0013] biasing means arranged to bias the valve elements and
the valve seats towards a position defining a minimum opening
degree of the valves, or towards a position defining a maximum
opening degree of the valves, wherein the second valve part and the
valve elements are connected in such a manner that the mutual
position of the first valve part and the second valve part
determines an opening degree of each of the valves.
[0014] The expansion valve of the invention defines flow paths
between the inlet opening and the at least two outlet openings.
Fluid medium in a liquid state is received at the inlet opening and
fluid medium in an at least partly gaseous state is delivered at
the outlet openings. In the present context the term `liquid state`
should be interpreted to mean that the fluid medium entering the
expansion valve via the inlet opening is substantially in a liquid
phase. Similarly, in the present context the term `at least partly
gaseous state` should be interpreted to mean that the fluid medium
leaving the expansion valve via the outlet openings is completely
in a gaseous phase, or at least a part, e.g. a substantial part, of
the volume of the fluid medium leaving the expansion valve is in a
gaseous phase. Accordingly, at least a part of the fluid medium
entering the expansion valve undergoes a phase transition from the
liquid phase to the gaseous phase when passing through the
expansion valve.
[0015] The inlet opening and the outlet openings may preferably be
fluidly connected to one or more other components, such as other
components of a refrigeration system. The expansion valve may
advantageously form part of a flow system, such as a flow
circuit.
[0016] The expansion valve comprises a first valve part and a
second valve part arranged movably relative to each other. This may
be achieved by mounting the first and/or the second valve part in a
manner which allows it/them to move relative to the remaining parts
of the expansion valve. Thus, the first valve part may be movable
while the second valve part is mounted in a fixed manner. As an
alternative, the second valve part may be movable while the first
valve part is mounted in a fixed manner. Finally, both of the valve
parts may be movably mounted. In all of the situations described
above a relative movement between the first valve part and the
second valve part is possible, thereby defining a mutual position
of the first valve part and the second valve part.
[0017] The first valve part has at least two valve seats formed
therein, and each of the valve seats is fluidly connected to one of
the outlet openings. At least two valve elements are arranged in
such a manner that the valve seats and the valve elements pair-wise
form at least two valves. The valve elements are further connected
to the second valve part in such a manner that the mutual position
of the first valve part and the second valve part determines an
opening degree of the valves. Accordingly, the valve elements
preferably performs movements relative to the valve seats when the
first valve part and the second valve part perform relative
movements. Thus, the opening degrees of the valves, and thereby the
amount of fluid medium supplied to each of the outlet openings, can
be adjusted by adjusting the mutual position of the first valve
part and the second valve part. Since the opening degrees of the
valves are defined by the mutual position of the first valve part
and the second valve part, the opening degrees are adjusted
synchronously, thereby at least substantially maintaining a
distribution key among the outlet openings.
[0018] The expansion valve further comprises biasing means arranged
to bias the valve elements and the valve seats towards a position
defining a minimum opening degree of the valves, or towards a
position defining a maximum opening degree of the valves. In the
case that the biasing means is arranged to bias the valve elements
and the valve seats towards a position defining a minimum opening
degree of the valves, the biasing means will attempt to close the
valves, and when the expansion valve is operated to cause the
valves to be opened, work must be performed against the biasing
force provided by the biasing means. On the other hand, in the case
that the biasing means is arranged to bias the valve elements and
the valve seats towards a position defining a maximum opening
degree of the valves, the biasing means will attempt to keep the
valves open, and when the expansion valve is operated to cause the
valves to be closed, work must be performed against the biasing
force provided by the biasing means.
[0019] In any event, the biasing force provided by the biasing
means defines a point of equilibrium for the relative movements of
the valve seats and the valve elements. Designing and positioning
the biasing means carefully thereby allows a correspondence between
a movement force applied for providing relative movement between
the valve parts and opening degree of the valves to be designed.
For instance, the biasing force may be selected in such a manner
that a `soft` closing of the valve is obtained, and/or in such a
manner that a specific applied moving force results in a specific
opening degree.
[0020] The valve elements may form part of the second valve part.
According to this embodiment, relative movements between the first
valve part and the second valve directly results in corresponding
relative movements between the valves seats and the valve elements.
For instance, the relative movements between the first valve part
and the second valve part may be substantially linear movements
causing each of the valve elements to simultaneously move towards
or away from the corresponding valve seat. The valve parts may
each, e.g., be or comprise a substantially disk shaped part having
the valve seats and the valve elements, respectively, formed on
surface parts thereof. In this case the valve seats may be in the
form of through-going bores of the disk forming the first valve
part, and the valve elements may be in the form of protruding parts
formed on a surface of the disk forming the second valve part which
is facing the first valve part.
[0021] As an alternative, the valve elements may form separate
parts being operatively connected to the second valve part.
According to this embodiment the valve elements and the second
valve part may be arranged on opposing sides of the first valve
part, and moving the first valve part and the second valve part
towards each other may cause the second valve part to
simultaneously push the valve elements in a direction away from the
valve seats, thereby increasing the opening degrees of the valves
defined by the valve elements and valve seats. In this case the
biasing means may advantageously be arranged to push the valve
elements in a direction towards the valve seats. Thereby, when
moving the first valve part and the second valve part away from
each other, the biasing means will ensure that the valve elements
are moved towards the valve seats, thereby decreasing the opening
degree of the valves.
[0022] The biasing means may be or comprise at least one spring,
such as a compressible spring. The spring may be in a compressed
state, in which case the spring force acts to push two parts, e.g.
the first and second valve parts or the first valve part and one or
more valve elements, away from each other. Alternatively, the
spring may be in a stretched state, in which case the spring force
acts to pull two parts, e.g. the first and second valve parts or
the first valve part and one or more valve elements, towards each
other.
[0023] The valve elements may be of a needle type, or they may be
of a ball type. Alternatively, the valve elements may be of any
other suitable kind.
[0024] The expansion valve may further comprise a thermostatic
element, and the first valve part and/or the second valve part may
be operatively connected to the thermostatic element, relative
movements of the first valve part and the second valve part thereby
being caused by the thermostatic element. According to this
embodiment, the thermostatic element determines the opening degrees
of each of the valves defined by the valve seats and the valve
elements, i.e. the thermostatic element simultaneously determines
the mass flow to each of the outlet openings.
[0025] The biasing means may, in this case, be arranged to
counteract movements caused by the thermostatic element in response
to an increase in pressure. According to this embodiment, biasing
force provided by the biasing means and the moving force
originating from the thermostatic element in response to changes in
pressure, in combination define an equilibrium which determines the
opening degrees of the valves.
[0026] As an alternative, the relative movements between the valve
parts, and thereby the opening degrees of the valves defined by the
valve seats and the valve elements, may be controlled by means of
other suitable kinds of actuators.
[0027] According to a second aspect the present invention provides
a refrigeration system comprising: [0028] at least one compressor,
[0029] at least one condenser, [0030] at least two evaporators
arranged in parallel along a refrigerant flow path of the
refrigeration system, and [0031] an expansion valve according to
any of the preceding claims, said expansion valve being arranged in
such a manner that each of the valves is arranged to deliver
refrigerant to one of the evaporators.
[0032] Thus, the expansion valve according to the first aspect of
the invention may advantageously be arranged in a refrigeration
path of a refrigeration system, e.g. a refrigeration system used in
a cooling arrangement or an air condition system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The invention will now be described in further detail with
reference to the accompanying drawings in which
[0034] FIG. 1 is a cross sectional view of an expansion valve
according to a first embodiment of the invention, and
[0035] FIG. 2 is a cross sectional view of an expansion valve
according to a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] FIG. 1 is a cross sectional view of an expansion valve 1
according to a first embodiment of the invention. The expansion
valve 1 comprises a first valve part 2 having a number of valve
seats 3, two of which are visible, formed therein. The expansion
valve 1 further comprises a second valve part 4 having a number of
valve elements 5 of a needle type, two of which are visible,
forming part thereof. The valve seats 3 and the valve elements 5
are arranged relative to each other in such a manner that a number
of valves are defined by pairs of valve seats 3 and valve elements
5.
[0037] The first valve part 2 and the second valve part 4 are
movable relative to each other along a substantially vertical
direction of the Figure, i.e. in such a manner that the valve
elements 5 are movable towards and away from the valve seats 3.
Thereby the relative position of the first valve part 2 and the
second valve part 4 determines the relative position of the valve
seats 3 and the valve elements 5. Due to the substantially conical
shape of the valve elements 5, the relative position of the first
valve part 2 and the second valve part 4 determines the size of a
passage through each valve seat 3, and thereby the opening degree
of each of the valves defined by the pairs of valve seats 3 and
valve elements 5.
[0038] The expansion valve 1 further comprises biasing means in the
form of a compressible spring 6. The spring 6 is arranged between
the first valve part 2 and the second valve part 4. It may be in a
compressed state, in which case it pushes the first valve part 2
and the second valve part 4 in a direction away from each other.
Since the valve seats 3 form part of the first valve part 2 and the
valve elements 5 form part of the second valve part 4, the spring 6
also pushes the valve seats 3 and the valve elements 5 in a
direction away from each other, i.e. towards a position defining a
maximum opening degree of the valves.
[0039] Alternatively, the spring 6 may be in a stretched state, in
which case it pulls the first valve part 2 and the second valve
part 4, and thereby the valve seats 3 and the valve elements 5, in
a direction towards each other, i.e. towards a position defining a
minimum opening degree of the valves.
[0040] The second valve part 4 is operatively connected to a
thermostatic element (not shown), and the relative position of the
first valve part 2 and the second valve part 4 is thereby
determined by the thermostatic element.
[0041] The expansion valve 1 of FIG. 1 may operate in the following
manner. Fluid medium in a substantially liquid state enters the
expansion valve 1 via an inlet opening as illustrated by arrow 7.
The fluid medium is led through the expansion valve 1 towards the
valve seats 3, and further on towards outlet openings 8, eventually
leaving the expansion valve 1 via the outlet openings 8. During
this the fluid medium is expanded, and the fluid medium leaving the
expansion valve 1 via the outlet openings 8 is therefore in an at
least partly gaseous state.
[0042] FIG. 2 is a cross sectional view of an expansion valve 1
according to a second embodiment of the invention. Similarly to the
embodiment shown in FIG. 1, the expansion valve 1 of FIG. 2
comprises a first valve part 2 having a number of valve seats 3
formed therein, and a second valve part 4. The first valve part 2
and the second valve part 4 are movable relative to each other
along a substantially vertical direction of the Figure.
[0043] The expansion valve 1 further comprises a number of valve
elements 5, two of which are visible, in the form of separate
elements arranged movably with respect to the valve seats 3 and in
such a manner that a number of valves are defined by pairs of valve
seats 3 and valve elements 5.
[0044] The valve elements 5 are arranged in such a manner that they
are allowed to extend through the openings defined by the valve
seats 3 and in abutment with the second valve part 4. Biasing means
in the form of compressible springs 6 are arranged between the
valve elements 5 and a base part 9 of the expansion valve 1. The
springs 6 are in a compressed state, thereby pushing the valve
elements 5 towards the valve seats 3 and into abutment with the
second valve part 4. Thus, the springs 6 push the valve elements 5
towards a position defining a minimum opening degree of the
valves.
[0045] Since the valve elements 5 are arranged in abutment with the
second valve part 4, and since the springs 6 ensure a firm abutment
between the valve elements 5 and the second valve part 4, the valve
elements 5 perform movements corresponding to the movements of the
second valve part 4. Thus, when the first valve part 2 and the
second valve part 4 are moved relative to each other in a direction
away from each other, the valve elements 5 and the valve seats 3
are moved in a direction towards each other, thereby decreasing the
opening degrees of the valves defined by the valve seats 3 and the
valve elements 5. Similarly, when the first valve part 2 and the
second valve part 4 are moved relative to each other in a direction
towards each other, the valve seats 3 and the valve elements 5 are
pushed away from each other, thereby increasing the opening degrees
of the valves defined by the valve seats 3 and the valve elements
5. Due to the substantially conical shape of the valve elements 5,
the relative position of the first valve part 2 and the second
valve part 4 thus determines the size of a passage through each
valve seat 3, and thereby the opening degrees of the valves.
[0046] The second valve part 4 is operatively connected to a
thermostatic element (not shown), and the relative position of the
first valve part 2 and the second valve part 4 is thereby
determined by the thermostatic element.
[0047] The expansion valve 1 of FIG. 2 may operate in the following
manner. Fluid medium in a substantially liquid state enters the
expansion valve 1 via an inlet opening as illustrated by arrow 7.
The fluid medium is led through the expansion valve 1 towards the
valve seats 3, and further on towards outlet openings 8 formed in
the base part 9 and fluidly connected to the valve seats 3. The
fluid medium leaves the expansion valve 1 via the outlet openings
8. During this the fluid medium is expanded, and the fluid medium
leaving the expansion valve 1 via the outlet openings 8 is
therefore in an at least partly gaseous state.
[0048] While the present invention has been illustrated and
described with respect to a particular embodiment thereof, it
should be appreciated by those of ordinary skill in the art that
various modifications to this invention may be made without
departing from the spirit and scope of the present.
* * * * *