PLAQUE PORTE-SOUPAPE COMPRENANT DES TROUS D'ASPIRATION MODIFIES POUR L'AUGMENTATION DE L'ECOULEMENT DE REFRIGERANT D'UN COMPRESSEUR

VALVE PLATE WITH MODIFIED SUCTION HOLES TO INCREASE REFRIGERANT FLOW FOR COMPRESSOR

Abrégé français

La modification des trous d'aspiration de la plaque porte-soupape selon l'invention a pour but d'augmenter le débit de réfrigérant du compresseur. Les trous d'aspiration modifiés (11 et 12) sont spécialement conçus pour présenter une forme fuselée dont le diamètre est supérieur au niveau de la partie supérieure et inférieur au niveau de la partie inférieure (20). La cloison de la plaque porte-soupape (16) présente la même hauteur que la plaque porte-soupape. Cela va permettre de réduire la perte de charge de frottement du réfrigérant dans le cylindre, ce qui résulte en une amélioration du débit de réfrigérant, une augmentation de la pression d'aspiration et une augmentation du coefficient de débit.

Abrégé anglais

The modification of the suction holes of the valve plate would increase the refrigerant flow rate of the compressor. The modified suction holes (11 and 12) are specially designed to have tapering form with the larger diameter at the top and smaller at the bottom (20). The valve plate partition (16) has the same height as the valve plate. These will reduce the friction loss of the refrigerant in the cylinder, which will result in an improvement of the refrigerant flow rate, more suction pressure, and the higher coefficient discharge.

Revendications

6
Claims
1. The valve plate after modified the suction holes to increase the
refrigerant flow rate is
consisted of:
a. A cylinder and piston operated by electrical motor will draw the
refrigerant from
the inlet (lower pressure) and compress the refrigerant out to the exit hole
in order
to increase the pressure and liquefy the refrigerant. The refrigerant would be
processed through the suction and discharge holes on the valve plate (10)
attached
to the end of the cylinder. The reduction of the friction would increase the
refrigerant flow efficiency.
b. The valve plate (10) is composed of the first suction hole (11) and the
second
suction hole (12), both of which are placed at the tip of cylinder. The first
and
second holes are characterized by standard cylindrical hole shape which is
composed of an arc (14) and a linear plane (15). The linear planes of both
holes
are positioned in parallel to each other, divided by the valve plate partition
(16).
Specification:
- The
first and the second holes, which have larger diameter at the top (13) and
smaller
at the bottom (21), in the incremental tapering slope (20). This tapering
slope reduces
the friction loss and improves the efficiency of refrigerant flow at the
suction hole.
This will result in improved compression efficiency from better coefficient of
discharge.
2. In reference to Claim#1 describing the valve plate suction holes after the
modification to
increase the refrigerant flow rate, the first (11) and second (12) suction
holes are tapered
to form semi-circular chambers (20) where the line from the larger edge (13)
to the inner
smaller edge (21) of the suction hole is angulated to the horizontal center
plane.
3. In reference to Claim#2 describing the valve plate with modified suction
holes to increase
the refrigerant flow rate, the line from the larger edge (13) to the inner
smaller edge (21)
of the suction hole is angulated to the horizontal plane less than 90 degree
(23).

7
4. In reference to Claim#1-3 describing the valve plate with modified suction
holes to
increase the refrigerant flow rate, the valve plate partition (16) has the
same height as the
suction valve plate (10).
5. In reference to Claim#1-4 describing the valve plate with modified suction
holes to
increase the refrigerant flow rate, the semi-circular chamber (20) of the
valve plate (10)
has the tapering slope to the bottom of the valve plate (10) assembled to the
opening of
the suction pipe (18).
6. In reference to Claim#1-5 describing the valve plate with modified suction
holes to
increase the refrigerant flow rate, the first (11) and second (12) suction
holes have higher
coefficient of discharge than the original model by 4.37%.

Description

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Invention : VALVE PLATE WITH MODIFIED SUCTION HOLES TO INCREASE
REFRIGERANT FLOW FOR COMPRESSOR
Background
In reference to Patent # 15933, we have described a suction valve for closed-
loop compressor
which contains a number of suction holes. The suction and discharge processes
of refrigerant are
cycling in the refrigeration system. The refrigerant will be processed through
suction and
discharge holes of a valve plate connected to the top of cylinder. The suction
holes are machined
to make the rectangle valve plate having chambers, and the rim of chambers are
perpendicular to
the valve surfaces to which the surfaces are parallel. The surfaces of the
valve plate are
perpendicular with the outer rim of the plate. The valve plate contains two
suction holes which
their upper surfaces are designed to have smaller areas than the lower surface
of the suction
chambers with the partition of suction holes located in the middle of the two
holes.
In reference to Patent# 15933, the enlargement of the suction hole to improve
the refrigerant
flow rate would create a difficult machinery installation in a limited space,
and to increase the
stress at the suction valve during the valve opening and closing may lead to
suction valve
malfunction. In addition, minimizing the partition thickness between two
suction holes in a
limited space may harm the partition during the opening and closing of the
suction valve.
Therefore, the improvement of refrigerant flow rate is critically dependent to
the size of the
suction hole.
Thus, Patent#15933 has a weakness. The suction holes in the valve plate are
machined to have
chambers which are likely formed by tapering slope on the top of holes. The
suction holes are
machined through the rectangle valve plate, and their centerlines are
perpendicular to the valve
surfaces to which the surfaces are parallel. The surfaces of the vale plate
are perpendicular with
the outer rim of the plate. The chambers create connection between the suction
holes. The
surface area of the suction hole which is smaller than the lower surface of
the chamber would
create turbulent flow. The flow is impeded by the smaller surface area of the
lower part of the
chamber resulting in the deviation of flow pathway. This would result in
suboptimal velocity,
mass flow rate, and coefficient of discharge, which is an interesting area of
improvement.

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This new invention has two suction holes which have larger diameter at the top
and smaller
diameter at the bottom, in the incremental slope that has the beginning of the
top edge angulate
less than 90 degree with the center line of the hole. This slope will
eliminate the friction loss of
the refrigerant in the cylinder, which will result in an improvement of the
refrigerant flow rate
and the coefficient discharge.
The refrigerant will flows through the connection between the suction pipe and
the first and the
second holes. The height of partition between the holes is equal to the valve
plate height (see
detail in the full claim).
Objects of the invention
This valve plate modified to improve the refrigerant flow rate for a
compressor has two suction
holes and it is situated at the end of the cylinder and the suction valve. The
two holes have larger
diameter at the top and smaller at the bottom of the suction plate. The
incremental slope of the
holes from the top of the plate angulate with that of the bottom of the plate
in less than 90
degree. The two holes have a standard shape with one semi-circular side and a
linear shape on
the other side.
The refrigerant flows through the connection between the suction pipe and the
first and the
second holes. The partition between the holes remains the same height as the
valve plate height.
On the valve plate, there is also a discharge hole which is in line with the
center of the partition
between the first and the second holes.
This invention aims to improve the coefficient of discharge of the refrigerant
at the suction holes,
reduce the turbulent flow causing by from the smaller surface of the lower
part of the chamber
than that of the hole, and increase the flow velocity and mass flow rate. This
would make a
compressor working more efficiently.
Field of Invention
An engineering related to the modified valve plate to improve the refrigerant
flow rate for a
compressor.

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Complete Invention Description
Figure 1 and Figure 2 show schematic view of the valve plate after the
modification of the
suction holes to increase the refrigerant flow rate in the compressor having a
cylinder connected
to the electric motor driven piston. The piston draws the refrigerant from the
inlet, which has
lower pressure, and compress the refrigerant out to the exit hole in order to
increase the pressure
and liquefy the refrigerant. The refrigerant is flowed through the suction and
discharge holes on
the valve plate (10) attached to the end of the cylinder. Any reduction of the
suction friction
would increase the refrigerant flow efficiency.
The valve plate (10) is composed of two suction holes (11, 12), both of which
are placed at the
tip of cylinder. The first and the second suction holes are machined to be a
semi-circular shape
chamber (20), which have larger diameter at the top (13) and smaller at the
bottom (21), in the
incremental slope that angulate less than 90 degree (23) with the center line
of the hole (Figure
4). The first and second suction holes are characterized by standard semi-
circular shape, which is
composed of an arc (14) on one side and a linear plane (15) on the other side.
The linear planes
of both holes are positioned in parallel to each other. This tapering slope
reduces the friction loss
and improves the efficiency of refrigerant flow into the suction hole. This
will result in improved
compression efficiency through better coefficient of discharge. The partition
(16) has the same
height as the valve plate (10), which indicates excellent strength. At the
valve plate (10), there is
a discharge hole (19), positioned in the same alignment as the partition (16)
between the first
( I 1) and second (12) suction holes.
Figure 3 and Figure 4 show the cross section view of the valve plate (10) that
is machined to
have semi-circular chambers (20) with tapering slope, as previously mentioned
(See above).
Figure 5 shows the assembly of the valve plate (10) with the suction pipe
(18), where the center
of the suction pipe (18) is aligned to the suction partition (16) between the
first (11) and the
second (12) holes. The opening of the suction pipe (18) is positioned
oppositely to the valve
plate (10). On that opposite side, the suction holes are machined as sloped
semi-circular
chambers (20) to reduce the suction friction and make refrigerant flow through
the cylinder
effectively.

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Figure 6 illustrates the simulation of refrigerant flowing through the first
(11) and second (12)
holes. The outer radius of the refrigerant flow is magnified by the tapering
slope (20) following
the surface area of the valve plate (10). This indicates that it is designed
to efficiently utilize the
valve (10) surface area. This figure demonstrates the greater coefficient of
discharge and flow
velocity due to the reduced turbulence from the effect of tapering slope. The
reduction of the
turbulence will lead to better compression efficiency.
Figure 7 demonstrates a result comparison between the valve plate (10) of this
invention and the
original valve plate, conducted by Department of Aerospace Engineering,
Faculty of
Engineering, Kasetsart University, Thailand. The graph shows the lower
turbulent energy of this
model compared to the original model showing that the chance to have turbulent
of the modified
valve plate is lower than the original model.
Figure 8 shows a table of the same study conducted by Department of Aerospace
Engineering,
Faculty of Engineering, Kasetsart University, Thailand. The results showed
that the modified
valve plate had a better performance, particularly in the increased
coefficient of discharge by
4.37%, resulting in a greater refrigerant flow.
Brief description of figures
Figure 1 and Figure 2 show the schematic view of the valve plate after
modified to increase
refrigerant flow rate of the compressor.
Figure 3 and Figure 4 show the cross-section view of the modified valve plate
(10)
Figure 5 shows the assembly of the valve plate (10) with the suction pipe (18)
of the closed loop
compressor.
Figure 6 shows the simulation of the refrigerant flow
Figure 7 shows a graph result of a study by the Department of Aerospace
Engineering, Faculty of
Engineering, Kasetsart University, Thailand. This comparison demonstrates the
lower turbulent
energy of the improved model compared to the original model.

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Figure 8 shows a table result of a study by the Department of Aerospace
Engineering, Faculty of
Engineering, Kasetsart University, Thailand. This comparison demonstrates that
the improved
model has more efficient to the original model.
5 Best invention methodolo2v
See narrative details in Complete Invention Description section.

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