Title of Invention

IMPROVED ABSORPTION REFRIGERATOR

Abstract The purpose of the present invention is to improve the thermal efficiency of an absorption refrigerator. The absorption refrigerator is provided with the refrigerant heat recovery equipment 11 for performing heat exchange between the refrigerant which radiated heat and is condensed by heating the intermediate absorption solution in the low temperature regenerator 3 and is introduced into the condenser 4 through the refrigerant pipe 20, and a part of the dilute absorption solution discharged from the absorber 7 and sent to the high temperature regenerator 1 bypassing the low temperature heat exchanger 9, and the rotation speed of the absorption solution pump 18 is controlled by the controller 33 so that the temperature of the dense absorption solution detected by the temperature sensor 32 is higher than a predetermined temperature, for example 40°C.
Full Text SPECIFICATION
BACKGROWND OF THE INVENTION
1. Field of the Invention
The present invention relates to an absorbing refrigerator excellent in
thermal efficiency.
2. Detailed Description of the Prior Art
As shown in Fig.4, such an absorption refrigerator is known, as is devised
to reduce a necessary heating amount by a gas burner 2 and reduce fuel
consumption by sequentially sending the exhaust gas exhausted from the gas
burner 2 for heating and boiling the dilute absorption solution of the high
temperature regenerator 1 to a first exhaust gas heat recovery equipment 27
arranged between a high temperature heat exchanger 10 of an absorption
solution pipe 12 and a high temperature regenerator 1, and to a second exhaust
gas heat recovery equipment 28 arranged between a low temperature heat
exchanger 9 and a high temperature heat exchanger 10, and thereby the dilute
absorption solution transported to the high temperature regenerator 1 from an
absorber 7 is increased in temperature.
Namely, in the absorption refrigerator of the above construction, the dilute
absorption solution at about 40°C (at rated operation, thereafter the same)
exhausted from the absorber 7 is heated by the low temperature heat
exchanger 9, the second exhaust gas heat recovery equipment 28, the high
temperature heat exchanger 10, and the first exhaust gas heat exchanger 27,
respectively, to be raised up to around 140 °C, and flows into the high
temperature regenerator 1, therefore, fuel consumption of the gas burner 2 can
be saved.
Moreover, the absorption refrigerator is so constructed that when both the
exhaust gas discharged from the gas burner 2 and the dilute absorption solution
supplied from the absorber 7 are at low temperatures, the water vapor
contained in the exhaust gas is prevented from being condensed and dewed, by
increasing a flow rate of the dilute absorption solution flowing through the
absorption solution pipe 14 by increasing the opening of the a flow control valve
29, and preventing the exhaust gas from remarkably lowering in temperature by
decreasing heat recovering from the exhaust gas in the second exhaust gas
heat recovery equipment 28.
However, in the above-mentioned conventional absorption refrigerator,
the flow control valve has been arranged in the absorption solution pipe
bypassing the second exhaust gas heat recovery equipment, therefore, not a
little of the dilute absorption solution has flown into the exhaust gas heat
recovery equipment through the absorption solution pipe even if the flow control
valve is fully opened.
Therefore, when both the absorption solution and the exhaust gas are at
a low temperature at the time of being started or the like, the exhaust gas
temperature is excessively lowered even if the flow control valve is fully opened,
and the water vapor contained in the exhaust gas has been condensed and
dewed, and this has sometimes caused to corrode the heat exchanger and the
exhaust pipe
Moreover, most of the heat held by the exhaust gas discharged from the
gas burner is recovered enough, therefore, when heat recovery of the exhaust
gas is aimed at more than now, the exhaust gas temperature has become lower
than the dew point of the water vapor contained in the exhaust gas even not at
the time of starting operation, the water vapor has been dewed and sometimes
corroded the heat recovery equipment and the piping part, therefore, the thermal
efficiency needs to be improved by the other methods, and this has been a
problem to be solved.
SUMMARY OF THE INVENTION
To solve the problem of the prior art described above, the present
invention provides, as a first construction an absorption refrigerator, comprising :
a high temperature regenerator for obtaining a vapor of a refrigerant and
an intermediate absorbing solution from a dilute absorption solution by which
evaporates and separates a refrigerant by heating and boiling a dilute absorption
solution, to obtain a vapor of the refrigerant and an intermediate absorbing
solution from the dilute absorption solution ;
a low temperature regenerator which further vaporizes and separates the
refrigerant by heating the intermediate absorption solution generated and
supplied by said high temperature regenerator with the refrigerant vapor
regenerated by said high temperature regenerator, to obtain the refrigerant vapor
and a dense absorption solution ;
a condenser which is supplied with the refrigerant solution obtained by
heating and condensing the intermediate absorption solution by said low
temperature regenerator, and which also obtains the refrigerant solution by
cooling the refrigerant vapor regenerated and supplied by said low temperature
regenerator;
an evaporator in which the refrigerant solution supplied from said
condenser is sprayed on heat conductive pipes and the refrigerant evaporates by
absorbing the heat from the fluid flowing in the heat conductive pipes ;
an absorber for making the refrigerant vapor generated and supplied by
said evaporator absorb the dense absorption solution which is separated and
supplied from said low temperature regenerator with the refrigerant vapor into a
dilute absorption solution, and supplying it to said high temperature regenerator;
a low temperature heat exchanger for performing heat exchange between
the dilute absorption solution and the dense absorption solution going in and out
of said absorber; and
a high temperature heat exchanger for performing heat exchange
between the intermediate absorption solution and the dilute absorption solution
going in and out of the high temperature regenerator; characterized in that
the absorption refrigerator is provided with a refrigerant heat recovery
equipment for heat exchanging a part of the dilute absorption solution
discharged from the absorber with the refrigerant heat-radiated and discharged
from the low temperature regenerator bypassing the low temperature heat
exchanger, and a proportion control means for controlling the proportion of the
branched absorption solutions flowing through said refrigerant heat recovery
equipment and the low temperature heat exchanger.
In a second construction of the absorption refrigerator the proportion
control means is one of a rotation speed controllable pump arranged in the
absorption solution pipe from the absorber up to the refrigerant heat recovery
equipment, an opening adjustable flow control valve, and a regulation valve for
proportion of flow quantity arranged at the branch point of the absorption solution
pipe to the refrigerant heat recovery equipment and the absorption solution pipe
to the low temperature heat exchanger,
In a third construction of the absorption refrigerator, the flow rate of the
dilute absorption solution discharged from the absorber and supplied to the
refrigerant heat recovery equipment is controlled on the basis of the temperature
of the dense absorption solution discharged from the low temperature heat
exchanger after heat exchange with the dilute absorption solution, in the first or
second construction of the absorption refrigerator,
a fourth construction of an absorption refrigerator is arranged so as to
control the flow rate of the dilute absorption solution discharged from the
absorber and supplied to the refrigerant heat recovery equipment on the basis
of the temperature of the refrigerant discharged from the refrigerant heat
recovery equipment after heat exchange with the dilute absorption solution, in
the first or second construction of the absorption refrigerator,
a fifth construction of an absorption refrigerator arranged so as to limit the
dilute absorption solution discharged from the absorber and supplied to the
refrigerant heat recovery equipment to 10 to 30% of the whole dilute absorption
solution which is discharged from the absorber and is led to the high
temperature regenerator, in the first or second construction of the absorption
refrigerator,
a sixth construction of an absorption refrigerator wherein a fitter 'is
installed at each inlet side of the low temperature heat exchanger, the high
temperature heat exchanger, and the refrigerant heat recovery equipment also
a pressure detecting means for detecting a pressure difference is provided
across each filter; and a checking indication means for indicating to check the
filter based on the differential pressure detected by the pressure detecting
means, in one of the first through fifth constructions of the absorption
refrigerators, and
a seventh construction of an absorption refrigerator wherein the
respective filters installed at the inlet sides of the Sow temperature heat
exchanger and the refrigerant heat recovery equipment are replaced with a
single common filter arranged in the absorption solution pipe before the branch
point of the absorption solution pipe going to the low temperature heat
exchanger and the absorption solution pipe going to the refrigerant heat
recovery equipment, in one of the first through 5th constructions of the
absorption refrigerators
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
These and other objects and advantages of the present invention will
become clear from the following description with reference to the accompanying
drawings, wherein : Fig. 1 is an explanation view showing an embodiment of the
present invention ; Fig. 2 is an explanation view showing another embodiment
of the present invention ; Fig. 3 is an explanation view showing yet another
embodiment of the present Invention ; and Fig. 4 is an explanation view showing
the prior art.
[Description of Reference Numerals]
1: high temperature regenerator
2: gas burner
3: low temperature regenerator
4:condenser
5: hot drum
6: evaporator
7: absorber
8: cold drum
9: low temperature heat exchanger
10: high temperature heat exchanger
11: refrigerant heat recovery equipment
12-16: absorption solution pipe(s)
17,18: absorption solution pump(s)
18A: flow control valve
18B: regulation valve for proportion of flow quantity
20-22: refrigerant pipe(s)
23: refrigerant pump
24: cold water pipe
25: cooling water pipe
26: exhaust gas pipe
27: first exhaust gas heat recovery equipment
28: second exhaust gas heat recovery equipment
29: flow control valve
30-32, 32A temperature sensor(s)
33: controller
34: checking indication means
Fi-F6:filter(s)
PF1-PF6 differential pressure gauge(s)
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the present invention will be described below,
mentioning an example of an absorption refrigerator using water as a refrigerant
and an aqueous solution of lithium bromide (LiBr) as an absorption solution.
An embodiment of the present invention will be explained referring to
Fig 1. In the figure, the reference numeral 1 is a high temperature regenerator
constructed so as to evaporate and separate the refrigerant by heating the
absorption solution with the heating power of the gas burner 2 using, for
example, town gas as. fuel; the reference numeral 3 is a low temperature
regenerator; 4 is a condenser; 5 is a hot drum in which the low temperature
regenerator 3 and the condenser 4 are housed; 6 is an evaporator, 7 is an
absorber; 8 is a cold drum in which the evaporator 6 and the absorber 7 are
housed; 9 is a low temperature Heat exchanger; 10 is a high temperature heat
exchanger; 11 is a refrigerant heat recovery equipment; 12 to 16 are absorption
pipes; 17 to 19 are absorption solution pumps; 20 to 22 are refrigerant pipes; 23
is a refrigerant pump; 24 is a cold water pipe; 25 is a cooling water pipe; 26 is
an exhaust gas pipe through which the exhaust gas discharged from the gas
burner 2 passes; 27 is the first exhaust gas heat recovery equipment; 28 is the
second exhaust gas heat recovery equipment; 29 is a flow control valve placed
in the absorption solution pipe 12 downstream side from the branch part of the
absorption solution pipe 14 and upstream side from the exhaust gas heat
recovery equipment 28, 30 is a temperature sensor which is installed in a
downstream part of the exhaust gas pipe 26 and detects the exhaust gas
temperature; 31 is a temperature sensor which is installed in the upstream part
of the absorption solution pipe 12 and detects the temperature of the dilute
absorption solution before heat-exchanged, 32 is a temperature sensor which is
installed in the downstream part of the absorption solution pipe 16 and detects
the temperature of the dense absorption solution which has heat-exchanged
with the dilute absorption solution >n the low temperature heat exchanger 9 and
has radiated heat; and 33 is a controller for controlling the opening of the flow
control valve 29 so that the temperature sensor 30 continuously deters a
predetermined temperature, for example, 100°C, and also controlling a quantity
of the dilute absorption solution made to flow into the refrigerant heat recovery
equipment 11 bypassing the low temperature heat exchanger 9 by controlling
the rotation speed of the absorption solution pump 18 so that the temperature
detected by the temperature sensor 32 is not lower than a predetermined
temperature, for example 40°c.
Moreover, F1-F5 are filters installed at the respective inlet sides of the
low temperature heat exchanger 9, the high temperature heat exchanger 10,
and the refrigerant heat recovery equipment 11, and PF1-PF5 are differential
pressure gauges for detecting pressure differences across the respective filters
installed across them and are configured to output the detected pressure
differences to the controller 33.
In the absorption refrigerator of the construction described above, when
the dilute absorption solution is heated and boiled in the high temperature
regenerator 1 by burning town gas by the gas burner 2, refrigerant vapor
evaporated and separated from the dilute absorption solution, and an
intermediate absorption solution increased in the density of the absorption
solution due to the separation of the refrigerant vapor are obtained.
The high temperature refrigerant vapor generated by the high
temperature regenerator 1 goes into the low temperature regenerator 3 through
the upstream part of the refrigerant pipe 20, heats the intermediate absorption
solution, which is generated in the high temperature regenerator 1 and goes
into the low temperature regenerator 3 through the absorption solution pipe 15
via the high temperature heat exchanger 10, radiates heat to be condensed,
and enters the condenser 4 through the downstream part of the refrigerant pipe
20 in which the refrigerant heat recovery equipment 11 intervenes.
Moreover, the refrigerant evaporated and separated from the
intermediate absorption solution by being heated in the low temperature
regenerator 3 enters the condenser 4, being heat-exchanged with the water
flowing through the cooling water pipe 25, to be condensed and liquefied, and
entering the evaporator 6 through the refrigerant pipe 21 together with the
condensed refrigerant supplied from the refrigerant pipe 20.
The refrigerant solution collected in the bottom of the evaporator 6 is
sprayed on the heat conductive pipe 24A connected with the cold water pipe 24
by the refrigerant pump 23 lying in the refrigerant pipe 22, and is evaporated by
being heat-exchanged with the water supplied through the cold water pipe 24,
and cools down the water flowing inside the heat conductive pipe 24A.
The refrigerant evaporated by the evaporator 6 enters the absorber 7,
and is absorbed into the absorption solution which is heated by the low
temperature regenerator 3 to evaporate and separate the refrigerant and is
more increased in density, namely, the refrigerant is absorbed into the dense
absorption solution which is supplied from the absorption solution pipe 16 by the
absorption solution pump 19 via the low temperature heat exchanger 9 and is
sprayed from above.
Then, the absorption solution which has absorbed the refrigerant in the
absorber 7 and has become thinner in density, namely, the dilute absorption
solution is fed back to the high temperature regenerator 1 by operation of the
absorption solution pump 17, 18.
When the absorption refrigerator is operated as described above the
cold water cooled by the vaporization heat of the refrigerant in the heat
conductive pipe 24A piped inside of the evaporator 6 can circularly be supplied
to an air conditioning load, not shown, via the cold water pipe 24, therefore,
cooling operation such as air conditioning can be carried out.
in the absorption refrigerator of the construction described above, a part
of the dilute absorption solution to be fed back to the high temperature
regenerator 1 from the absorber 7 by the operation of the absorption solution
pumps 17, 18 passes through the low temperature heat exchanger 9 lying in the
absorption solution pipe 12, and the remaining part passes through the
refrigerant heat recovery equipment 11 lying in the absorption solution pipe 13,
and they are heated by the respective heat exchangers
Moreover, a quantity of the dilute absorption solution heated by the
exhaust gas discharged from the gas burner 2 via the second exhaust gas heat
recovery equipment 28 is controlled by the flow control valve 29 intervened in
the absorption solution pipe 12, and the whole quantity of the dilute absorption
solution to be fed back to the high temperature regenerator 1 from the absorber
7 is made to flow through the high temperature heat exchanger 10 and the first
exhaust gas heat recovery equipment 27, and is heated by each of them
Namely, a part of the dilute absorption solution of about 40°C discharged
from the absorber 7 to the absorption solution pipe 12 is heat-exchanged in the
low temperature heat exchanger 9 with the dense absorption solution of about
90 oC which is discharged from the low temperature regenerator 3 into the
absorption solution pipe 15 and is flowing into the absorber 7, and the
remaining part thereof exchanges heat with the refrigerant solution of about
95°C in the refrigerant pipe 20 which is condensed by the low temperature
regenerator 3 and is flowing into the condenser 4, and is raised in temperature.
And, the respective dilute absorption solutions heat-exchanged and heated in
the low temperature heat exchanger 9 and the refrigerant heat recovery
equipment 11 join together to be a dilute absorption solution of, for sample,
about 80oc, and flow into the second exhaust gas heat recovery equipment 28.
The flow rate of the dilute absorption solution flowing into the second
exhaust gas heat recovery equipment 28 is controlled by the controller 33 for
adjusting the opening of the flow control valve 29 placed in the absorption
solution pipe 12. For example, when the temperature sensor 30 is detecting a
temperature higher than the predetermined 100°C, the controller 33 increases
the opening of the flow control valve 29, and supplies more dilute absorption
solution being returned to the high temperature regenerator 1 from the absorber
7 to the second heat recovery equipment 28 to promote recovery of the heat
held by the exhaust gas, therefore, the thermal efficiency is improved and the
fuel consumption of the gas burner 2 is reduced.
Moreover, the dilute absorption solution heated by passing through the
second exhaust gas heat recovery equipment 28, and the dilute absorption
solution, which does not pass through the second exhaust gas. heat recovery
equipment 28, therefore, which is not heated thereby, are joined and pass
through the heat exchanger 10 and the first exhaust gas heat recovery
equipment 27, and exchange heat with the intermediate absorption solution
flowing from the high temperature regenerator 1 to the low temperature
regenerator 3 through the absorption solution pipe 15, and with the exhaust gas
of about 200 °C exhausted from the gas burner 2, and flow into the high
temperature regenerator 1 as a dilute absorption solution at about 140 °C,
therefore, the gas burner 2 can save its fuel consumption.
Further, the refrigerant solution which is condensed by the low
temperature regenerator 3 and flows into the condenser 4 passing through the
downstream part of the refrigerant pipe 20, exchanges heat with the dilute
absorption solution of about 40oC in the refrigerant heat recovery equipment 11
and heats it as described above, and the refrigerant itself is cooled down to
about 45°C and is decreased in calorie to be radiated to the cooling water
flowing through the cooling water pipe 25, therefore, necessary heat gain in the
high temperature regenerator 1 can be decreased, and the absorption
refrigerator is remarkably improved in thermal efficiency also at this point.
Moreover, the rotation speed of the absorption solution pump 18 is
controlled by the controller 33 so that the temperature of the dense absorption
solution detected by the temperature sensor 32 after the heat exchange in the
low temperature heat exchanger 9 is higher than the predetermined 40 °C,
therefore, the dense absorption solution flowing through the downstream part of
the absorption solution pipe 16 is not crystallized and clogging of the absprption
solution pipe 16 due to the crystallization does not occur.
Moreover, when the temperature sensor 30 is detecting a temperature
lower than 100°C, it is possible to reduce the calorie to be recovered from the
exhaust gas to the minimum of zero by fully closing the flow control valve 29 to
the minimum, until the whole quantity of the dilute absorption solution is made
to flow through the absorption solution pipe 14 by bypassing the second
exhaust gas heat recovery equipment 28, therefore, the temperature of the
exhaust gas exhausted via the exhaust gas pipe 26 is maintained at 100°C
higher than the dew-point temperature (the dew-point temperature of the
exhaust gas is 60-70°C when town gas, namely, natural gas is used as fuel),
and so even at the time of starling or partial load operation of the absorption
refrigerator when the exhaust gas temperature is low, water vapor contained in
the exhaust gas cannot be condensed to produce drain water, and the drain
water does not cause a corrosion problem either.
Further, since the filters F1-F6 are installed on the inlet sides of the low
temperature heat exchanger 9, the high temperature heat exchanger 10, and
the refrigerant heat recovery equipment 11, scales are filtered out by the filters
F1-F6 even if the scales enter the passages of the absorption solution and the
refrigerant.
Moreover, the filters F1 and F2 can be replaced with a single filter (shown
by imaginary lines in Fig. 1) to be provided on the discharge side of the
absorption solution pump 17 and on the upstream side of the branch part of the
piping.
Therefore, inconvenience of clogging the flow passages is not caused
even when the low temperature heat exchanger 9, the high temperature heat
exchanger 10, the refrigerant heat recovery equipment 11, etc. are constructed
of plate-type heat exchangers improved in heat exchange efficiency by
narrowing the flow passages as proposed in, for example, the Japanese Patent
Laid-Open 1987-131196 the Japanese Patent Laid-Open 1991-271697, the
Japanese Patent Laid-Open 1992-73595, the Japanese Patent Laid-Open
1995-190649, the Japanese Patent LaW-Open 1995-229637, etc.
Moreover, the differential pressure gauges PF1-PF6 are installed across
the filters F1-F6, and since the differential pressure gauges are configured so
that the controller 33 issues an alarm by the checking indication means 34
when a predetermined pressure difference of, for example, 30kPa or higher is
not detected across each filter, normal circulation of the solutions can be
secured by cleaning the filters, and so on by observing the operation status of
the checking indication means 34.
Moreover, the temperature of the refrigerant which radiates heat by
heating the intermediate absorption solution in the low temperature regenerates
3 and further radiates heat by heating the dilute absorption solution also in the
refrigerant heat recovery equipment 11 is lowered to around 45°C as mentioned
above, the refrigerant does not need to be sent to the condenser 4 for being
cooled down by the cooling water flowing through the cooling water pipe 25.
Therefore, it is also possible to shorten the pipe length and simplify the
piping structure by connecting the downstream side of the refrigerant pipe 20
not to the condenser 4 but to the evaporator 6 so that the condensed refrigerant
can be made to flow into it, as shown by an imaginary line (In Fig.1, the shortest
parts of the refrigerant pipes 20, 21 are connected via the imaginary lines, but in
a practical machine, the hot drum 5 is located on an upper side, and the cold
drum 8 and the refrigerant heat recovery equipment 11 are located on a lower
side, therefore, it is possible to place the evaporator 6 of the cold drum 8 and
the refrigerant heat recovery equipment 11 adjacent to each other and connect
between them via a short refrigerant pipe).
Moreover, as shown in Fig.2, the flow control valve 18A is installed in the
absorption solution pipe 13 instead of the absorption solution pump 18. Or, as
shown in Fig.3, the rate of flow proportion control valve 18B is installed at the
branch part of the absorption solution pipes 12, 13, and the flow control valve
18A or the rate of flow proportion control valve 18B can be configured so as to
control a quantity of the dilute absorption solution flowing through the low
temperature heat exchanger 9 by the controller 33 so that the temperature of
the dense absorption solution having radiates heat in the low temperature heat
exchanger 9 is not detected at the predetermined 40 oC or lower by the
temperature sensor 32.
Moreover, it is also possible to determine and construct the internal
resistance (the diameters and lengths of the pipes) of the refrigerant heat
recovery equipment 11 and the absorption solution pipe 13 so that 10-30% of
the absorption solution is made to bypass the low temperature heat exchanger
9 and flow through the refrigerant heat recovery equipment 11, without installing
the absorption solution pump 18, the flow control valve 18A, and the rate of flow
proportion control valve 18B in the absorption solution pipe 13 (including the
branch part/joint part of the absorption solution pipe 12).
Moreover, instead of the temperature sensor 32, the temperature sensor
32A is installed on the downstream side of the refrigerant pipe 20 so as to be
able to detect the temperature of the refrigerant having radiates heat by heat
exchange with the dilute absorption solution in the refrigerant heat recovery
equipment 11, and thereby it is also possible to arrange the rotation speed of
the absorption solution pump 15, the flow control valve 18A, the opening of the
rate of flow proportion control valve 18B, etc. to be controlled by the controller
33 so that the temperature of the refrigerant detected by the temperature sensor
32A after heat exchange in the refrigerant heat recovery equipment 11 is, for
example, the temperature of the dilute absorption solution detected by the
temperature sensor 31 before heat exchange in the refrigerant heat recovery
equipment 11 plus a predetermined temperature, for example, plus 5°C, and it is
aiso possible to arrange them to surety lower the temperature of the condensed
refrigerant directly supplied to the condenser 4 or the evaporator 6 down to a
predetermined temperature.
Further, the configuration may be made up to control the valve to
open/close or to be switched by the controller 33 so that an exhaust gas
temperature detected by the temperature sensor 30 is not lower than, for
example, 100°C, by arranging an inexpensive on-off valve in the absorption
solution pipe 12 on the upstream side of the second heat recovery equipment
28 or arranging an inexpensive switching valve at the branch part (or joining
part) of the absorption solution pipes 12, 14, instead ot the expensive flow
control valve 29.
Moreover, instead of the absorption solution pipe 14 hypassing the
second heat recovery equipment 28, not only an exhaust gas pipe bypassing
the second heat recovery equipment 28 is arranged, but also a passage
switching valve is arranged at the branch part (or joining part) of the exhaust
pipe. Or, a on-off valve is arranged in the exhaust gas pipe passing through the
second heat recovery equipment 28, and thereby open/close or passage
switching of the valve may be controlled by the controller 33 so that the
temperature of the exhaust gas. which has flown through the second heat
recovery equipment 28 and exchanged heat with the dilute absorption solution,
is not lower than the predetermined 100°c
Moreover, the absorption refrigerator may exclusively be used for cooling
operation of air conditioning as described above, and may also be arranged so
as to able to perform heating operation of air conditioning by arranging piping
connection permitting to directly supply the cold drum 8 with the refrigerant
vapor heat-generated by the high temperature regenerator 1 and the absorption
solution from which the refrigerant vapor has been separated by vaporization,
heating the dilute absorption solution by the gas burner 2 without making the
cooling water flow through the cooling water pipe 25, and circularly supplying a
load with water heated, for example, at 55oC by the heat conductive pipe 24 A of
the evaporator 6 through the cold water pipe 24 (preferred to be called a hot
water pipe when hot water circulates).
Further, as a fluid to be supplied to an air-conditioning load by cooling it
by the evaporator 6, not only water or the like may be supplied without phase
change as described in the above embodiment, but also fluorocarbon or the like
may be supplied with phase change so as to be able to transfer heat utilizing
latent heat.
Moreover, by installing the pressure gauges across the respective filters
F1-F6 to detect the pressure differences across the filter, such a warning
means can also be arranged as indicates cleaning the filters when a
predetermined pressure difference is not detected across the filters.
While the presently preferred embodiment of the present invention has
been shown and described, it will be understood that the present invention is
not limited thereto, and that various, changes and modifications may be made by
those skilled in the art without departing from the scope of the invention as set
forth in the appended claims.
According to the present invention as described above, since the
refrigerant heat recovery equipment in which a pgrt of the dilute absorption
solution discharged from the absorber exchanges heat with the refrigerant
discharged from the low temperature regenerator after heat radiation, bypassing
the low temperature heat exchanger, and the rate of flow proportion control
means for controlling the proportion of the dilute absorption solution branching
to flow through the refrigerant heat recovery equipment and the fow temperature
heat exchanger, are installed, the remaining heat held by the refrigerant
condensed by heat radiation to the intermediate absorption solution in the tow
temperature regenerator and discharged to the refrigerant pipe can be heat-
recovered by the dilute absorption solution in the refrigerant heat recovery
equipment, and the fuel consumption of the combustion equipment attached to
the high temperature regenerator can be reduced.
Moreover, the proportion of the dilute absorption solutions branching to
flow through the refrigerant heat recovery equipment and the low temperature
heat exchanger can be controlled, and for example, in the absorption
refrigerator in which the proportion is adjusted by controlling the flow rate of the
dilute absorption solution discharged from the absorber and supplied to the
refrigerant heat recovery equipment based on the temperature of the dense
absorption solution discharged from the low temperature heat exchanger after
having exchanged heat with the dilute absorption solution, the dense absorption
solution flowing into the absorber after having radiated heat to the dilute
absorption solution in the low temperature heat exchanger can be prevented
from being crystallized by setting the temperature of the dense absorption
solution to an appropriate temperature.
Moreover, in the absorption refrigerator arranged so as to control the
aforementioned proportion by controlling the flow rate of the dilute absorption
solution discharged from the absorber and supplied to the refrigerant heat
recovery equipment based on the temperature of the refrigerant discharged
from the refrigerant heat recovery equipment after having exchanged heat with
the dilute absorption solution, the temperature of the condensed refrigerant can
surely be lowered to a predetermined temperature by setting the temperature of
the refrigerant to a suitable temperature, and thus a necessary amount of heat
radiation by the condenser is reduced, and a piping arrangement directly
supplying the condensed refrigerant to the evaporator is also possible.
Further, in the absorption refrigerator arranged so as to limit the dilute
absorption solution discharged from the absorber and supplied to the refrigerant
heat recovery equipment to 10-30% of the whole dilute absorption solution
discharged from the absorber and reaching the high temperature regenerator,
the temperature of the dense absorption solution releasing heat through heat
exchange with the dilute absorption solution in the low temperature heat
exchanger is surely lowered. Therefore, the refrigerant is promptly absorbed
into the absorption solution in the absorber into which the dense absorption
solution flows.
Further, in the absorption refrigerator wherein the fitters are installed on
respective inlet sides of the low temperature heat exchanger, the high
temperature heat exchanger, and the refrigerant heat recovery equipment, and
wherein the differential pressure detecting means are also installed for detecting
the differential pressures across the respective filters, and wherein the checking
indication means is arranged for indication of checking the filters based on the
differential pressures detected by the differential pressure detecting means,
scales are filtered even if they enter the flow passages of the absorption
solution and the refrigerant.
Therefore, inconvenience of clogging the flow passages is r\ot caused
even when the low temperature heat exchanger, the high temperature heat
exchanger, the refrigerant heat recovery equipment, etc. are constructed of
plate-type heat exchangers improved in heat exchange efficiency by narrowing
the flow passages as proposed in, for example, the Japanese Patent Laid-Open
1987-131195. the Japanese Patent Laid-Open 1991-271697, the Japanese
Patent Laid-Open 1992-73595, the Japanese Patent Laid-Open 1995-190649,
the Japanese Patent laid-Open 1995-229687, etc. Further, normal circulation
of the solutions can be secured by cleaning the filters by observing the
operation status of the checking indication means.
WE CLAIM :
1. An absorption refrigerator, comprising :
a high temperature regenerator for obtaining a vapor of a refrigerant and
an intermediate absorbing solution from a dilute absorption solution by which
evaporates and separates a refrigerant by heating and boiling a dilute absorption
solution, to obtain a vapor of the refrigerant and an intermediate absorbing
solution from the dilute absorption solution ;
a low temperature regenerator which further vaporizes and separates the
refrigerant by heating the intermediate absorption solution generated and
supplied by said high temperature regenerator with the refrigerant vapor
regenerated by said high temperature regenerator, to obtain the refrigerant vapor
and a dense absorption solution ;
a condenser which is supplied with the refrigerant solution obtained by
heating and condensing the intermediate absorption solution by said low
temperature regenerator, and which also obtains the refrigerant solution by
cooling the refrigerant vapor regenerated and supplied by said low temperature
regenerator;
an evaporator in which the refrigerant solution supplied from said
condenser is sprayed on heat conductive pipes and the refrigerant evaporates by
absorbing the heat from the fluid flowing in the heat conductive pipes ;
an absorber for making the refrigerant vapor generated and supplied by
said evaporator absorb the dense absorption solution which is separated and
supplied from said low temperature regenerator with the refrigerant vapor into a
dilute absorption solution, and supplying it to said high temperature regenerator;
a low temperature heat exchanger for performing heat exchange between
the dilute absorption solution and the dense absorption solution going in and out
of said absorber; and
a high temperature heat exchanger for performing heat exchange
between the intermediate absorption solution and the dilute absorption solution
going in and out of the high temperature regenerator; characterized in that
the absorption refrigerator is provided with a refrigerant heat recovery
equipment for heat exchanging a part of the dilute absorption solution
discharged from the absorber with the refrigerant heat-radiated and discharged
from the low temperature regenerator bypassing the low temperature heat
exchanger, and a proportion control means for controlling the proportion of the
branched absorption solutions flowing through said refrigerant heat recovery
equipment and the low temperature heat exchanger.
2. An absorption refrigerator as claimed in claim 1, wherein the proportion
control means is anyone of a rotation speed controllable pump(s) arranged in the
absorption solution pipe from the absorber up to the refrigerant heat recovery
equipment, an opening adjustable flow control valve, and a regulation valve for
proportion of flow quantity arranged at a branch point of the absorption solution
pipe to the refrigerant heat recovery equipment and the absorption solution pipe
to the low temperature heat exchanger.
3. An absorption refrigerator as claimed in claim 1 or 2, wherein the flow rate
of the dilute absorption solution discharged from the absorber and supplied to
the refrigerant heat recovery equipment is controlled on the basis of the
temperature of the dense absorption solution discharged from the low
temperature heat exchanger after heat-exchanging with the dilute absorption
solution.
4. An absorption refrigerator as claimed in claim 1 or 2, wherein the flow
rate of the dilute absorption solution discharged from the absorber and then
supplied to the refrigerant heat recovery equipment is controlled on the basis of
the temperature of the refrigerant discharged from the low temperature heat
exchanger after heat-exchanging with the dilute absorption solution.
5. An absorption refrigerator as claimed in claim 1 or 2, wherein the dilute
absorption solution discharged from the absorber and supplied to the refrigerant
heat recovery equipment is limited to 10 to 30% of the whole dilute absorption
solution which is discharged from the absorber and is led to the high temperature
regenerator.
6. An absorption refrigerator as claimed in any one of the claims 1 to 5,
wherein a filter is installed at each inlet side of the low temperature heat
exchanger, the high temperature heat exchanger, and the refrigerant heat
recovery equipment ; also a pressure detecting means for detecting a pressure
difference is provided across each filter, and a checking indication means is
provided for indicating to check the filter based on the differential pressure
detected by the pressure detecting means.
7. An absorption refrigerator as claimed in claim 6, wherein the filters
installed at the inlet sides of the low temperature heat exchanger and the
refrigerant heat recovery equipment are replaced with a single common filter
arranged in the absorption solution pipe before branching the absorption solution
pipe going to the low temperature heat exchanger and the absorption solution
pipe going to the refrigerant heat recovery equipment.
8. An absorption refrigerator substantially as herein described, particularly
with reference to the accompanying drawings.
The purpose of the present invention is to improve the thermal efficiency of an
absorption refrigerator. The absorption refrigerator is provided with the
refrigerant heat recovery equipment 11 for performing heat exchange between
the refrigerant which radiated heat and is condensed by heating the
intermediate absorption solution in the low temperature regenerator 3 and is
introduced into the condenser 4 through the refrigerant pipe 20, and a part of
the dilute absorption solution discharged from the absorber 7 and sent to the
high temperature regenerator 1 bypassing the low temperature heat exchanger
9, and the rotation speed of the absorption solution pump 18 is controlled by the
controller 33 so that the temperature of the dense absorption solution detected
by the temperature sensor 32 is higher than a predetermined temperature, for
example 40°C.

Documents:

95-kol-2003-granted-abstract.pdf

95-kol-2003-granted-claims.pdf

95-kol-2003-granted-correspondence.pdf

95-kol-2003-granted-description (complete).pdf

95-kol-2003-granted-drawings.pdf

95-kol-2003-granted-form 1.pdf

95-kol-2003-granted-form 18.pdf

95-kol-2003-granted-form 2.pdf

95-kol-2003-granted-form 3.pdf

95-kol-2003-granted-form 5.pdf

95-kol-2003-granted-gpa.pdf

95-kol-2003-granted-letter patent.pdf

95-kol-2003-granted-priority document.pdf

95-kol-2003-granted-reply to examination report.pdf

95-kol-2003-granted-specification.pdf

95-kol-2003-granted-translated copy of priority document.pdf


Patent Number 219081
Indian Patent Application Number 95/KOL/2003
PG Journal Number 17/2008
Publication Date 25-Apr-2008
Grant Date 23-Apr-2008
Date of Filing 19-Feb-2003
Name of Patentee SANYO ELECTRIC CO. LTD.
Applicant Address 5-5,KEIHANHONDORI 2-CHOME, MORIGUCHI-SHI, OSAKA-FU
Inventors:
# Inventor's Name Inventor's Address
1 IRAMINA KAZUYASU C/O SANYO ELECTRIC CO. LTD 5-5, KEIHANHONDORI, 2-CHOME, MORIGUCHI-SHI, OSAKA-FU
2 FURUKAWA MASAHIRO C/O SANYO ELECTRIC CO. LTD 5-5, KEIHANHONDORI, 2-CHOME, MORIGUCHI-SHI, OSAKA-FU
3 YAMAZAKI SHIGUMA C/O SANYO ELECTRIC CO. LTD 5-5, KEIHANHONDORI, 2-CHOME, MORIGUCHI-SHI, OSAKA-FU
4 KAMADA YASUSHI C/O SANYO ELECTRIC CO. LTD 5-5, KEIHANHONDORI, 2-CHOME, MORIGUCHI-SHI, OSAKA-FU
PCT International Classification Number F25 B 15/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2002-110372 2002-04-12 Japan