U.S. patent number 3,586,462 [Application Number 04/820,753] was granted by the patent office on 1971-06-22 for absorption refrigeration machine pump.
This patent grant is currently assigned to Carrier Corporation. Invention is credited to Richard A. English, Kenneth K. Kaiser.
United States Patent |
3,586,462 |
Kaiser , et al. |
June 22, 1971 |
ABSORPTION REFRIGERATION MACHINE PUMP
Abstract
An absorption refrigeration machine having a generator and
condenser on the high side thereof and an evaporator and absorber
on the low side employing a pulser-type solution pump to minimize
"slugging," transfer noncondensible gases and solution from the low
side to the high side of the machine, store noncondensible gases on
the high side thereof and utilize the collected noncondensible
gases to dampen pump discharge pulsations.
Inventors: |
Kaiser; Kenneth K. (Camby,
IN), English; Richard A. (Indianapolis, IN) |
Assignee: |
Carrier Corporation (Syracuse,
NY)
|
Family
ID: |
25231630 |
Appl.
No.: |
04/820,753 |
Filed: |
May 1, 1969 |
Current U.S.
Class: |
417/394; 62/50.6;
62/476 |
Current CPC
Class: |
F04B
45/033 (20130101); F25B 15/025 (20130101); Y02A
30/27 (20180101); Y02B 30/62 (20130101); Y02A
30/277 (20180101) |
Current International
Class: |
F25B
15/02 (20060101); F04B 45/00 (20060101); F04B
45/033 (20060101); F04b 009/10 (); F17c
007/02 () |
Field of
Search: |
;417/395,394
;103/44,44D,152,224 ;62/99,55A |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Walker; Robert M.
Claims
We claim:
1. A pump for use in an absorption refrigeration system comprising
a cylindrical casing having a circular bottom closure and a domed
top closure,
a first partition dividing said casing into a noncondensible gas
storage chamber and a second chamber, said first partition being a
generally circular member affixed to said cylindrical casing,
a second partition associated with said casing and said first
partition to divide said second chamber into an inlet chamber and a
transfer chamber, said second partition being cylindrical and
affixed to said bottom closure and said generally circular first
partition,
inlet valve means associated with said second partition to allow
passage of liquid and gases from the inlet chamber to the transfer
chamber,
discharge valve means associated with said second partition to
allow passage of liquid and gases from the transfer chamber to the
storage chamber,
means disposed in the transfer chamber for pumping a mixture of
liquid and gases from the inlet chamber to the storage chamber, the
gases passing into the storage chamber separating from the liquid
and collecting in an upper portion of the storage chamber to form a
cushioned layer to dampen pump pulsations, and
discharge means communicating with the storage chamber closely
adjacent with bottom of the chamber of passage of liquid from the
discharge chamber.
2. A pump according to claim 1 wherein said discharge means
comprises a tube projecting downwardly through said domed top
closure toward said generally cylindrical partition to said casing,
the open lower end of said tube being spaced closely adjacent the
generally circular partition for passage of liquid from the storage
chamber.
3. A pump according to claim 2, wherein said inlet valve means is
positioned below the normal level of collected fluid within the
inlet chamber but closely adjacent the surface of the fluid so that
passage of liquid from the inlet chamber to the transfer chamber
creates a vortex to induce gas collected in the inlet chamber into
the transfer chamber.
4. A pump according to claim 2 further including deflector means
disposed in the storage chamber opposite said discharge valve means
to prevent discharge of liquid from the valve into the upper
portion of the storage chamber.
5. A pump according to claim 2 wherein said means for pumping fluid
includes a resilient diaphragm adapted to be cyclically flexed by
pulsating hydraulic pressure.
6. A pump according to claim 5 wherein said resilient diaphragm has
a generally cylindrical shape with a hemispherical end thereto,
said diaphragm being disposed within said cylindrical
partition.
7. A pump according to claim 6 further including a purge valve
affixed to said domed top closure and communicating with the
interior of said storage chamber for bleeding excess noncondensible
gases from said storage chamber.
Description
BACKGROUND OF THE INVENTION
Absorption refrigeration systems comprising a high-pressure side,
including a generator and a condenser, and a low-pressure side,
including an evaporator and an absorber, require a solution
transfer mechanism such as a pump to transfer weak solution from
the low side of the system to the high side. The pressure
difference across the system may be large, necessitating the use of
a positive displacement reciprocating piston pump or a diaphragm
pump, both of which provide a pulsed output which can create
excessive noise in the system.
The solution to be pumped passes from the absorber to the pump.
While the machine is operating, the pump receives "slugs" of liquid
from the absorber, rather than a steady flow. This can cause
undesirable fluctuating pump noise and could possibly damage the
pump mechanism.
Another problem which may arise in the operation of an absorption
refrigeration system is the generation of noncondensible gases such
as hydrogen which may have a detrimental effect on the performance
of the system. It is desirable to provide means to separate the
noncondensible gases and retain them out of circulation in the
system. It is difficult to separate the gases from the absorbent
solution on the high-pressure side of the system due to the
tendency of the gas to remain suspended in the solution in the form
of fine bubbles. The gases are therefore ordinarily separated and
collected on the low-pressure side of the machine. However, storage
of the noncondensible gases on the low-pressure side of the system
where separation is easily accomplished requires an undesirably
large storage tank because of the volume of gas at low pressure. It
is desirable to "pump" these separated gases to the high side of
the machine along with the solution for storage on the high
pressure side of the system.
SUMMARY OF THE INVENTION
This invention relates to an absorption refrigeration system
employing a pump comprised of a housing having first and second
partitions therein to provide a first low-pressure chamber for
receiving solution and noncondensible gases from the absorber, a
second chamber having transfer means therein for receiving solution
and gases from the first chamber, and a third chamber for receiving
solution and noncondensible gases from said transfer means and
storing the noncondensible gases therein to dampen the pulsations
generated by the transfer means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of an absorption refrigeration
system;
FIG. 2 is a sectional view of the preferred embodiment of the pump
of the present invention; and
FIG. 3 is a sectional view taken along line III-III of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the drawing, there is shown a refrigeration
system comprising an absorber 10, a condenser 12, an evaporator or
chiller 14, a generator 16, a liquid-suction heat exchanger 18, and
a vapor distributor 20 connected to provide refrigeration. A pump
22 is employed to circulate weak absorbent solution from absorber
10 to generator 16.
As used herein, the term "weak absorbent solution" refers to
solution which is weak in absorbent power, and the term "strong
absorbent solution" refers to a solution which is strong in
absorbent power. A suitable absorbent for use in the system
described is water; a suitable refrigerant is ammonia.
Liquid refrigerant condensed in condenser 12 passes through
refrigerant liquid passage 24 to the liquid-suction heat exchanger.
The liquid-suction heat exchanger 18 includes a housing 26 having a
refrigerant restrictor 28 at the upstream end and a refrigerant
restrictor 30 at the downstream end thereof. A portion of the
liquid refrigerant supplied to the liquid-suction heat exchanger 18
flashes upon passing through restrictor 28 due to the low pressure
existing downstream of the restrictor, thereby cooling the
remainder of the refrigerant in the housing 26. The cooled
refrigerant liquid and flashed refrigerant vapor then pass through
restrictor 30 into heat exchanger 32 of chiller 14.
A heat exchange medium such as water is passed over the exterior of
heat exchanger 32 where it is chilled by giving up heat to
evaporate the refrigerant within the heat exchanger. The chilled
heat exchange medium passes out of chiller 14 through line 34 to
suitable remote heat exchangers (not shown) after which it is
returned to the chiller through inlet 36 for rechilling.
The cold refrigerant evaporated in heat exchanger 32, along with
any small quantity of absorbent which may be carried over to the
heat exchanger with the refrigerant from the condenser, passes into
refrigerant vapor passage 38 of liquid-suction heat exchanger 18.
The refrigerant vapor and absorbent liquid, which may have a large
quantity of refrigerant absorbent therein, passes through
refrigerant vapor passage 38 in heat exchange relation with the
refrigerant passing through housing 26. Refrigerant vapor passage
38 is provided with a turbulator 39 which consists of a twisted
metal strip to provide a tortuous flow path for the vapor to
provide optimum heat transfer between the vapor and liquid in
passage 38 and the liquid refrigerant in housing 26. By passing the
vapor and liquid in passage 38 in heat transfer with the liquid
refrigerant in housing 26, a large quantity of refrigerant in the
absorbent liquid in passage 38 is vaporized. The heat required for
vaporization is therefore removed from the liquid in housing 26,
thereby reducing the temperature of the liquid refrigerant supplied
to heat exchanger 32. This heat transfer within the liquid-suction
heat exchanger 18 provides an increase in the absorption machine
efficiency by transferring heat from the liquid supplied thereto
from the condenser to the refrigerant vapor nd absorbent liquid
discharged from the chiller.
Refrigerant vapor and absorbent solution from passage 38 is
supplied to refrigerant distributor 20 through line 40. Strong
solution which is supplied from the generator to distributor 20
through line 41 mixes with the vapor and solution supplied to the
distributor through line 40. The refrigerant vapor-absorbent
solution mixture from distributor 20 is supplied to individual
circuits 42 of the absorber 10 through absorber supply tubes 43. A
cooling medium, preferably ambient air is passed over the surface
of the absorber in heat exchange relation with the solution therein
for cooling the absorbent solution to promote the absorption of the
refrigerant vapor by the solution. The same cooling medium may be
supplied to condenser 12 in heat exchange relation with refrigerant
vapor therein to condense the refrigerant.
Cold weak absorbent solution passes from absorber 10 through line
21 into pump 22.
Referring to FIG. 2, the pump 22 comprises a cylindrical casing 23
having a circular bottom closure 44 and a domed top closure 45
suitably affixed thereto as by welding. A first generally circular
partition member 46, which is affixed to cylindrical casing 23 as
by welding, and a cylindrical partition member 47, which is affixed
to bottom closure 44 and partition member 46 by suitable means such
as welding, divide the pump into an inlet chamber 48, a pump or
transfer chamber 49 and a noncondensible gas storage chamber 50. An
inlet fitting 51 is provided in casing 23 for passing solution and
noncondensible gases from line 21 into chamber 48. An inlet valve
53 is suitably affixed to cylindrical partition 47 at a location
just below the normal level of solution within chamber 48 for
reasons to be hereinafter explained. The valve allows passage of
fluid from chamber 48 into chamber 49 but prevents passage of fluid
in the reverse direction. A discharge valve 54 is provided in
partition member 46 to allow passage of solution and noncondensible
gases from chamber 49 into chamber 50. A flexible diaphragm 55
having a generally cylindrical shape with a hemispherical-shaped
end which is supported on a perforated mandrel 56 is disposed
within chamber 49 and held in place by end plate 57 which is
affixed to bottom closure 44 by suitable means such as bolts 58. A
pulsating flow of hydraulic fluid from a suitable hydraulic pump 59
(refer to FIG. 1) is provided to the interior of mandrel 56 through
hydraulic line 63.
When hydraulic fluid under pressure is supplied to the interior of
mandrel 56, the diaphragm 55 is expanded toward partition member
47. The fluid and noncondensible gases within the space between
diaphragm 55 and partition 47 is forced through discharge valve 54
into chamber 50. When the hydraulic pressure within diaphragm 55 is
reduced, the diaphragm will return to its original shape, causing
solution from chamber 48 to be drawn into chamber 49 through inlet
valve 53. Since the inlet valve 53 is located just under the normal
level of solution within chamber 48, the reduced pressure within
chamber 49 will cause solution from chamber 48 to pass therein and
create a vortex which causes a quantity of noncondensible gases
collected in the upper portion of chamber 48 to be drawn into
chamber 49.
A deflector 65 is provided in chamber 50 to deflect the solution
and noncondensible gases discharged from chamber 49 through
discharge valve 54 to prevent solution from spraying into the upper
portion of chamber 50. In order to minimize absorption of
noncondensible gases collected in the top portion of chamber 50,
deflector 65 is utilized to minimize turbulence which may be
created by the unrestricted discharge of solution and gas into the
chamber 50 through discharge valve 54. A pump discharge tube 67
having its open lower end near the bottom of chamber 50 is provided
for passing solution from chamber 50 into line 62 while retaining
the noncondensible gases therein. The noncondensible gases which
are passed from chamber 48 into chamber 50 collect in the upper
portion of the chamber and are stored therein at pump discharge
pressure. The collected gases form a cushioning layer. This
cushioning layer of noncondensible gases in chamber 50 is very
effective in dampening the pulses generated by the movement of
diaphragm 55. A suitable valve 69 is provided for periodic purging
of noncondensible gases from chamber 50. It should be understood
that when the machine is initially started or purged, chamber 50
will fill with liquid before liquid flows out discharge tube 67. As
noncondensible gases are pumped into chamber 50, they will collect
in the top portion of the chamber which will force the liquid level
down. Before an amount of compressed noncondensible gases is
collected which would displace liquid to a level near the inlet to
tube 67, the chamber should be purged to prevent passage of the
gases from the chamber.
The storage of noncondensible gases in chamber 50 is very effective
in dampening the pulses generated by the movement of diaphragm
55.
The weak solution in line 62 is passed through rectifier heat
exchange coil 64 in heat exchange relation with hot strong solution
passing through heat exchange coil 66 disposed within coil 64 and
with the hot refrigerant vapor flowing through rectifier shell 68
in contact with the outer surface of coil 64. The weak solution
from coil 64 is discharged into the upper portion of generator 16
along with any vapor which is formed in coil 64 due to heat
exchange with the hot vapor passing thereover and the hot solution
flowing therethrough.
Generator 16 comprises a shell 70 having tapered fins 72 suitably
affixed thereto as by welding. The generator is heated by a gas
burner 74 or other suitable heating means. The weak solution is
boiled in generator 16 to concentrate the solution, thereby forming
a strong solution and refrigerant vapor.
The hot strong absorbent solution passes upwardly through the
analyzer section of generator 16 through analyzer coil 76 in heat
exchange with the weak solution passing downwardly over the coil.
The warm strong solution then passes through heat exchange coil 66
within coil 64 and line 41 into the distributor 20. A restrictor 78
is provided in line 41 so that the solution supplied to the vapor
distributor 20 is at the same pressure as the vapor in line 40.
Refrigerant vapor formed in generator 16 passes upwardly through
the analyzer section thereof where it is concentrated by mass heat
transfer with weak solution passing downwardly over analyzer coil
76. Analyzer plates 80 in generator 16 provide a tortuous path for
flow of solution and vapor to assure intimate contact therebetween
to improve the mass heat transfer. The vapor then passes through
rectifier 68 in heat exchange relation with the weak solution
passing through coil 64. Absorbent condensed in rectifier 68 flows
downwardly into the generator along with the weak solution
discharged from coil 64. Refrigerant vapor passes from rectifier 68
through line 82 to condenser 12 to complete the refrigeration
cycle.
While we have described a preferred embodiment of our invention, it
is to be understood the invention is not limited thereto since it
may be otherwise embodied within the scope of the following
claims.
* * * * *