U.S. patent application number 15/767679 was filed with the patent office on 2018-10-18 for evaporative condenser and refrigeration system equipped with said evaporative condenser.
The applicant listed for this patent is Hidetoshi KANEO. Invention is credited to Hidetoshi KANEO.
Application Number | 20180299168 15/767679 |
Document ID | / |
Family ID | 58631504 |
Filed Date | 2018-10-18 |
United States Patent
Application |
20180299168 |
Kind Code |
A1 |
KANEO; Hidetoshi |
October 18, 2018 |
EVAPORATIVE CONDENSER AND REFRIGERATION SYSTEM EQUIPPED WITH SAID
EVAPORATIVE CONDENSER
Abstract
An evaporative condenser for use in a refrigeration system
includes an inclined plate-like refrigerant cooling portion for
cooling and condensing refrigerant, an inclined plate-like water
spraying portion for spraying the cooling portion with cooling
water to cool the refrigerant cooling portion, a casing having an
air inlet for taking in air, an air outlet for discharging air, and
a draft fan for generating airflow from the air inlet to the air
outlet inside the casing. The refrigerant cooling portion has
multiple condenser coils arranged in an inclined manner with
respect to the horizontal direction to cool the refrigerant while
causing the refrigerant to flow downward therethrough. The water
spraying portion has multiple water spraying nozzles arranged in an
inclined manner along the condenser coils to spray the condenser
coils with cooling water. The evaporative condenser efficiently
condenses and devolatilizes gaseous refrigerant delivered
sequentially after circulating in a condensing cooling cycle.
Inventors: |
KANEO; Hidetoshi; (Shizuoka,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KANEO; Hidetoshi |
Shizuoka |
|
JP |
|
|
Family ID: |
58631504 |
Appl. No.: |
15/767679 |
Filed: |
October 14, 2016 |
PCT Filed: |
October 14, 2016 |
PCT NO: |
PCT/JP2016/080522 |
371 Date: |
April 12, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2400/075 20130101;
F25B 2339/041 20130101; F25B 7/00 20130101; F25B 39/04 20130101;
F25B 1/00 20130101; F25B 9/008 20130101; F25B 25/005 20130101 |
International
Class: |
F25B 1/00 20060101
F25B001/00; F25B 7/00 20060101 F25B007/00; F25B 39/04 20060101
F25B039/04; F25B 9/00 20060101 F25B009/00; F25B 25/00 20060101
F25B025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 28, 2015 |
JP |
2015-212411 |
Jan 20, 2016 |
JP |
PCT/JP2016/051506 |
Claims
1. An evaporative condenser comprising: an inclined plate-like
refrigerant cooling portion for cooling and condensing refrigerant
delivered sequentially after circulating in a condensing cooling
cycle; an inclined plate-like water spraying portion for spraying
the refrigerant cooling portion with cooling water to cool the
refrigerant cooling portion; a casing having an air inlet for
taking in air and an air outlet for discharging air used for
evaporating cooling water sprayed from the water spraying portion
and a draft fan for generating an airflow from the air inlet to the
air outlet inside the casing; wherein: the refrigerant cooling
portion has a plurality of condenser coils arranged in a
downward-inclined manner with respect to the horizontal direction
to cool the refrigerant while causing the refrigerant to flow
therethrough downward; and the water spraying portion has a
plurality of water spraying nozzles arranged in an inclined manner
along the condenser coils to spray the condenser coils with the
cooling water.
2-6. (canceled)
7. The evaporative condenser according to claim 1, wherein the
water spraying portion is arranged in an inclined manner on the
windward side of the refrigerant cooling portion.
8. The evaporative condenser according to claim 1, including an
eliminator provided between the refrigerant cooling portion and the
draft fan and also between the water spraying portion and the draft
fan, said eliminator being arranged in an inclined manner along the
refrigerant cooling portion and the water spraying portion.
9. The evaporative condenser according to claim 1, wherein: the air
inlet is provided in one of a set of opposed side wall surfaces of
the casing; the air outlet is provided in a top surface of the
casing; the casing has a bottom wall surface opposed to said air
outlet; and the condenser coils are inclined downward from a
location adjacent an upper part of one of the side wall surfaces of
the casing toward said casing bottom wall surface.
10. The evaporative condenser according to claim 1, including a
cooling water clarifying portion, and wherein the water spraying
portion is connected to said cooling water clarifying portion for
clarifying the cooling water.
11. A refrigeration system configured with a condensing cooling
cycle having an evaporative condenser according to claim 1.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to evaporative condensers used
for a refrigeration system and, in particular, to an evaporative
condenser used for a refrigeration system for cooling a freezer or
the like to condense/devolatilize refrigerant in a condensing
cooling cycle that has been evaporated by removing heat from
primary refrigerant circulating in a primary refrigerating cycle
that is combined with the configuration of the refrigeration
system, and a refrigeration system including the evaporative
condenser.
BACKGROUND OF THE INVENTION
[0002] A known evaporative condenser used for refrigeration
equipment uses ammonia as refrigerant, the condenser including a
heat conductor having a number of straight refrigerant pipes for
cooling and condensing ammonia refrigerant delivered sequentially
from a compressor of the refrigeration equipment, a water spraying
nozzle for spraying the heat conductor with cooling water to cool
the heat conductor, a casing having an air inlet for taking in, and
an air outlet for discharging, air used for evaporating cooling
water sprayed from the water spraying nozzle, and a blower
installed near the air outlet of the casing to forcibly discharge
air through the air outlet. An example of this known evaporative
condenser is shown in Japanese patent application JP 2001-091102 A,
published on Apr. 6, 2001.
[0003] Another known evaporative condenser used for refrigeration
equipment uses carbon dioxide as refrigerant, the condenser
including a coil for cooling and condensing carbon dioxide
refrigerant delivered sequentially from an evaporator of the
refrigeration equipment, a nozzle for spraying the coil with
cooling water to cool the coil, a casing having an air inlet for
taking in and an air outlet for discharging air used for
evaporating cooling water sprayed from the nozzle, and a fan
installed near the air inlet of the casing to forcibly take in air
through the air inlet and discharge the air through the air outlet.
An example of this known evaporative condenser is shown in Japanese
patent application 2003-240360 A, published on Aug. 27, 2003.
[0004] However, since the above-described evaporative condenser
described in Patent Literature 1 has a structure in which gaseous
ammonia refrigerant is cooled within the horizontally arranged
refrigerant pipes, stagnation occurs in which ammonia refrigerant
condensed/devolatilized within the horizontally arranged
refrigerant pipes stagnates within and adheres to the refrigerant
pipes, and the liquid ammonia refrigerant stagnating within and
adhering to the refrigerant pipes prevents heat removal from the
remaining gaseous ammonia refrigerant, resulting in that the
gaseous ammonia refrigerant delivered sequentially from the
refrigeration equipment cannot be cooled efficiently and
condensed/devolatilized into liquid ammonia refrigerant.
[0005] This suffers from problems of an increase in the amount of
filled refrigerant, an increase in the diameter of the refrigerant
pipes for circulating refrigerant therethrough, an increase in the
capacity of the blower and therefore an increase in the noise level
due to an increase in the amount of air used to cool the
refrigerant pipes, an increase in the amount of cooling water
consumption due to an increase in the amount of air, and an
increase in the size and footprint of the evaporative condenser due
to them.
[0006] In the case of recovering and reusing cooling water, there
is also a problem that the refrigerant pipes may be contaminated
and/or become eroded due to concentration of impurities in the
original water and/or incorporation of dust and/or toxic gas in the
air.
[0007] Similarly, since the above-described evaporative condenser
described in Patent Literature 2 also has a structure in which
gaseous carbon dioxide refrigerant is cooled within the straight
pipe region of the horizontally arranged coil, stagnation occurs in
which carbon dioxide refrigerant condensed/devolatilized within the
straight pipe region of the horizontally arranged coil stagnates
within and adheres to the straight pipe region, and the liquid
carbon dioxide refrigerant stagnating within and adhering to the
straight pipe region prevents heat removal from the remaining
gaseous carbon dioxide refrigerant, resulting in having the space
to improve a structure for cooling the gaseous carbon dioxide
refrigerant delivered sequentially from the evaporator and
condensing/devolatilizing into liquid ammonia refrigerant.
SUMMARY OF THE INVENTION
[0008] The invention has hence been made to solve the
above-mentioned related art problems, that is, a first object
thereof is to reduce the amount of filled refrigerant due to
stagnation in which devolatilized refrigerant stagnates within a
condenser coil, a second object thereof is to reduce the footprint
of an evaporative condenser, a third object thereof is to reduce
the power and noise of a draft fan, a fourth object thereof is to
reduce the amount of cooling water consumption, and a fifth object
thereof is to keep the cooling water at a water quality suitable
for use, providing an evaporative condenser suitable for these
objects and a refrigeration system including the evaporative
condenser.
[0009] The invention solves the above-mentioned problems with an
evaporative condenser including an inclined plate-like refrigerant
cooling portion for cooling and condensing refrigerant delivered
sequentially after circulating in a condensing cooling cycle, an
inclined plate-like water spraying portion for spraying the
refrigerant cooling portion with cooling water to cool the
refrigerant cooling portion, a casing having an air inlet for
taking in and an air outlet for discharging air used for
evaporating cooling water sprayed from the water spraying portion,
and a draft fan for generating an airflow from the air inlet to the
air outlet inside the casing, in which the refrigerant cooling
portion has multiple condenser coils arranged in an inclined manner
with respect to the horizontal direction to cool the refrigerant
while causing the refrigerant to flow therethrough downward, and in
which the water spraying portion has multiple water spraying
nozzles arranged in an inclined manner along the condenser coils to
spray the condenser coils with the cooling water.
[0010] In a second aspect, the invention further solves the
above-mentioned problems by arranging the evaporative condenser
such that the water spraying portion is arranged in an inclined
manner on the windward side of the refrigerant cooling portion.
[0011] In a third aspect, the invention further solves the
above-mentioned problems by arranging the evaporative condenser
such that an eliminator provided between the refrigerant cooling
portion as well as the water spraying portion and the draft fan is
arranged in an inclined manner along the refrigerant cooling
portion and the water spraying portion.
[0012] In a fourth aspect, the invention further solves the
above-mentioned problems by arranging the evaporative condenser
such that the air inlet is provided in one of a set of opposed
casing side wall surfaces of the casing, that the air outlet is
provided in a top surface of the casing, and that the condenser
coils are arranged in an inclined manner from an upper part of the
casing side wall surface toward a casing bottom wall surface
opposed to the air outlet.
[0013] In a fifth aspect, the invention further solves the
above-mentioned problems by arranging the evaporative condenser
such that the water spraying portion is connected to a cooling
water clarifying portion for clarifying the cooling water.
[0014] In a sixth aspect, the invention further solves the
above-mentioned problems with a refrigeration system having an
evaporative condenser.
SUMMARY OF THE INVENTION
[0015] The evaporative condenser according to the invention
includes an inclined plate-like refrigerant cooling portion for
cooling and condensing refrigerant delivered sequentially after
circulating in a condensing cooling cycle, a water spraying portion
for spraying the refrigerant cooling portion with cooling water to
cool the refrigerant cooling portion, a casing having an air inlet
for taking in and an air outlet for discharging air used for
evaporating cooling water sprayed from the water spraying portion,
and a draft fan for generating an airflow from the air inlet to the
air outlet inside the casing, whereby gaseous refrigerant delivered
sequentially after circulating in the condensing cooling cycle can
be cooled and condensed into liquid refrigerant to be sent
sequentially into the circulation of the condensing cooling cycle
as well as the following specific advantageous effects can be
exhibited.
[0016] In accordance with the invention, the refrigerant cooling
portion has multiple condenser coils arranged in an inclined manner
with respect to the horizontal direction to cool the refrigerant
while causing the refrigerant to flow therethrough downward,
whereby when gaseous refrigerant undergoes heat removal through the
inner peripheral wall surfaces of the condenser coils to be cooled
while moving within the pipes of the condenser coils and thereby
undergoes removal of the latent heat of condensation to be
condensed/devolatilized to adhere to the inner peripheral wall
surfaces of the condenser coils as, for example, liquid film and/or
droplets, the adhering liquid refrigerant flows downward within the
pipes of the condenser coils under its own weight and stagnation in
which refrigerant stagnates cannot occur, which also promotes
condensation/devolatilization of the remaining gaseous refrigerant
and allows gaseous refrigerant delivered sequentially after
circulating in the condensing cooling cycle to be devolatilized
efficiently, resulting in a reduction in the amount of filled
refrigerant.
[0017] Further, compared to the case where a plate-like refrigerant
cooling portion is arranged horizontally as used in conventional
evaporative condensers, the piping length of the condenser coils,
which contributes to the evaporation of cooling water, is greater
in the inclined plate-like refrigerant cooling portion arranged in
an inclined manner, whereby the evaporative condenser can be
reduced in size and footprint to ensure that the refrigerant
cooling portion has the same surface area as that of conventional
evaporative condensers.
[0018] Also, if the evaporative condenser has the same footprint as
conventional evaporative condensers, the thickness of the condenser
coils is reduced to ensure that the refrigerant cooling portion has
the same surface area, whereby compared to the case of ventilation
through conventional condenser coils, even a lower ventilation rate
can achieve the same amount of ventilation required for cooling the
condenser coils, which allows the pressure loss of ventilation
through the condenser coils and therefore the power of the draft
fan to be reduced, resulting in a reduction in the noise due to
ventilation through the condenser coils.
[0019] Also, since the water spraying portion has multiple water
spraying nozzles arranged in an inclined manner along the condenser
coils to spray the condenser coils with the cooling water, the
distance between the water spraying nozzles and the condenser coils
is constant and the sprayed cooling water adheres evenly and
equally to the outer peripheral wall surfaces of the condenser
coils to flow downstream, whereby a larger amount of latent heat of
evaporation can be utilized from the cooling water sprayed from the
water spraying portion to reduce the amount of cooling water
consumption.
[0020] In accordance with the second aspect of the invention,
besides the above-mentioned advantageous effects, since the water
spraying portion is arranged in an inclined manner on the windward
side of the refrigerant cooling portion, a larger amount of sprayed
cooling water adheres to a lower part of each condenser coil, which
can promote generation of, for example, liquid film and/or droplets
on the inner peripheral wall surface in the lower part of each
condenser coil, resulting in a reduction in the time for stagnation
and adherence of liquid refrigerant.
[0021] Also, spraying in the forward direction, along the direction
of ventilation of the draft fan, reduces the pressure loss of
ventilation, whereby the power of the draft fan can be lower
compared to the case of spraying in the reverse direction against
the ventilation as in conventional water spraying portions.
[0022] In accordance with the third aspect of the invention,
besides the above-mentioned advantageous effects, since the
eliminator provided between the refrigerant cooling portion as well
as the water spraying portion and the draft fan is arranged in an
inclined manner along the refrigerant cooling portion and the water
spraying portion, cooling water sprayed from the water spraying
portion but contributing to the cooling of the refrigerant cooling
portion can be trapped and the trapped cooling water can flow under
its own weight toward a lower part of the eliminator to be
recovered earlier, compared to the conventional case where an
eliminator is provided at the air outlet of the casing, resulting
in a reduction in the amount of cooling water consumption.
[0023] Further, since the surface area of the eliminator
contributing to the trapping of cooling water increases, the
evaporative condenser can be reduced in size and footprint to
ensure that the eliminator has the same surface area as that of
conventional evaporative condensers.
[0024] Also, if the evaporative condenser has the same footprint as
conventional evaporative condensers, the thickness of the
eliminator is reduced to ensure that the eliminator has the same
surface area, whereby compared to the case of ventilation through
conventional eliminators, even a lower ventilation rate can achieve
the same amount of ventilation required for trapping the cooling
water, which allows the pressure loss of ventilation through the
eliminator and therefore the power of the draft fan to be reduced,
resulting in a reduction in the noise due to ventilation through
the eliminator.
[0025] In accordance with the fourth aspect of the invention,
besides the above advantageous effects, the air inlet is provided
in one of a set of opposed casing side wall surfaces of the casing,
the air outlet is provided in a top surface of the casing, and the
condenser coils are arranged in an inclined manner from an upper
part of the casing side wall surface toward a casing bottom wall
surface opposed to the air outlet, whereby if the refrigerant
cooling portion is arranged in, for example, a downward-inclined
manner by 60 degrees with respect to the horizontal direction to
form two sides of a so-called inverted equilateral triangle to
achieve the same surface area as that of conventional evaporative
condensers, the refrigerant cooling portion has two times as large
a surface area as desired if not changed, so that the refrigerant
cooling portion undergoes half reduction in thickness to have the
same surface area, which allows the pressure loss of air through
the condenser coils to be reduced as well as reduction in the power
of the draft fan and reduction in the noise due to the power
reduction to be achieved.
[0026] In accordance with the fifth aspect of the invention,
besides the above advantageous effects, since the water spraying
portion is connected to a cooling water clarifying portion for
clarifying the cooling water, concentrated impurities and/or
impurities such as dust and toxic gas from the air contained in the
cooling water trapped and recovered by the eliminator can be
removed to supply the cooling water to the water spraying portion,
which improves the quality of the cooling water and prevents
performance degradation of the condenser coils due to contamination
and/or erosion, whereby the frequency of maintenance can be
reduced.
[0027] In accordance with the sixth aspect of the invention, a
refrigeration system which is configured with a condensing cooling
cycle having an evaporative condenser as described above can
exhibit the same advantageous effects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a conceptual diagram illustrating a refrigeration
system that uses an evaporative condenser of the invention.
[0029] FIG. 2 is a schematic front perspective view of an
evaporative condenser according to a first example of the
invention.
[0030] FIG. 3 is a cross-sectional view through the section plane
indicated by reference signs 3-3 in FIG. 2.
[0031] FIG. 4A shows an exemplary refrigerant cooling portion in
the evaporative condenser of the invention.
[0032] FIG. 4B shows a variation of the refrigerant cooling portion
in the evaporative condenser of the invention.
[0033] FIG. 5 is a schematic front perspective view of an
evaporative condenser according to a second example of the
invention.
[0034] FIG. 6 is a cross-sectional view through the section plane
indicated by reference signs 6-6 in FIG. 5.
[0035] FIG. 7 is a conceptual diagram of the evaporative condenser
according to the second example of the invention with a cooling
water clarifying portion connected thereto.
[0036] FIG. 8 is a schematic front perspective view of an
evaporative condenser according to a third example of the
invention.
[0037] FIG. 9 is a cross-sectional view through the section plane
indicated by reference signs 9-9 in FIG. 8.
[0038] FIG. 10 is a cross-sectional view through the section plane
indicated by reference signs 10-10 in FIG. 8.
[0039] FIG. 11 is a schematic front perspective view of an
evaporative condenser according to a fourth example of the
invention.
[0040] FIG. 12 is a cross-sectional view through the section plane
indicated by reference signs 12-12 in FIG. 11.
DETAILED DESCRIPTION
[0041] The invention may specifically be implemented in any way as
long as pertaining to an evaporative condenser, also known by the
term "Evacon," including an inclined plate-like refrigerant cooling
portion for cooling and condensing refrigerant delivered
sequentially after circulating in a condensing cooling cycle, a
water spraying portion for spraying the refrigerant cooling portion
with cooling water to cool the refrigerant cooling portion, a
casing having an air inlet for taking in and an air outlet for
discharging air used for evaporating cooling water sprayed from the
water spraying portion, and a draft fan for generating an airflow
from the air inlet to the air outlet inside the casing, in which
the refrigerant cooling portion has multiple condenser coils
arranged in an inclined manner with respect to the horizontal
direction to cool the refrigerant while causing the refrigerant to
flow therethrough downward, and in which the water spraying portion
has multiple water spraying nozzles arranged in an inclined manner
along the condenser coils to spray the condenser coils with the
cooling water, whereby gaseous refrigerant delivered sequentially
after circulating in the condensing cooling cycle is
condensed/devolatilized efficiently.
[0042] For example, refrigerant used in the condensing cooling
cycle may include carbon dioxide, ammonia, non-CFC refrigerant of
hydrocarbon (such as propane, butane, and isobutane), and CFC
refrigerant (such as 134a). Any refrigerant may be used as long as
condensed/devolatilized to be liquid within the pipes of condenser
coils of the evaporative condenser.
[0043] Further, the water spraying portion for cooling the
refrigerant cooling portion may be positioned, for example, either
above, below, laterally to, on the windward side of, or on the
leeward side of the refrigerant cooling portion, and may
specifically be implemented in any way as long as it sprays the
refrigerant cooling portion with cooling water.
[0044] Also, the draft fan may be positioned, for example, either
near the air inlet on the windward side or near the air outlet on
the leeward side, and may specifically be implemented in any way as
long as it generates an airflow from the air inlet to the air
outlet inside the casing.
[0045] An evaporative condenser 100 used in a refrigeration system
S according to a first example of the invention will hereinafter be
described based on FIGS. 1 to 4B. Here, FIG. 1 is a conceptual
diagram illustrating the refrigeration system S that uses the
evaporative condenser 100 of the invention, FIG. 2 is a schematic
front perspective view of the evaporative condenser 100 according
to the first example of the invention, FIG. 3 is a cross-sectional
view through the section plane indicated by reference signs 3-3 in
FIG. 2, FIG. 4A shows an exemplary refrigerant cooling portion 120
in the evaporative condenser 100 of the invention, and FIG. 4B
shows a variation of the refrigerant cooling portion 120 in the
evaporative condenser 100 of the invention.
[0046] As shown in FIG. 1, the refrigeration system S is formed by
combining a primary ammonia refrigeration cycle Sa in which ammonia
circulates to be used as refrigerant, a secondary carbon dioxide
cooling cycle Sb in which carbon dioxide, cooled by the ammonia
refrigerant in the primary ammonia refrigeration cycle Sa,
circulates to be used as refrigerant, and an ammonia condensing
cooling cycle Sc in which refrigerant R, for example, carbon
dioxide refrigerant circulates to cool the ammonia refrigerant in
the primary ammonia refrigeration cycle Sa.
[0047] The primary ammonia refrigeration cycle Sa has an ammonia
condensing cascade condenser Sa1 and an ammonia evaporating cascade
condenser Sa2. The secondary carbon dioxide cooling cycle Sb has an
evaporator Sb1. The ammonia condensing cooling cycle Sc has an
evaporative condenser 100. The evaporative condenser 100 may be
included in any increased or decreased number depending on the
scale of the refrigeration system S.
[0048] In the ammonia condensing cascade condenser Sa1, the ammonia
refrigerant in the primary ammonia refrigeration cycle Sa undergoes
heat removal to be cooled and condensed/devolatilized by liquid
refrigerant R1 (R) delivered from the evaporative condenser 100 in
the ammonia condensing cooling cycle Sc. The liquid refrigerant R1
(R) removes heat from the ammonia refrigerant to be
evaporated/vaporized. The thus evaporated/vaporized refrigerant Rg
(R) is put back to the evaporative condenser 100 and again cooled
to be condensed/devolatilized.
[0049] The liquid refrigerant R1 (R), which has been cooled
sufficiently and condensed/devolatilized in the evaporative
condenser 100, thus removes heat from the ammonia refrigerant to be
evaporated/vaporized, while the ammonia refrigerant is cooled and
has a lower condensation/devolatilization temperature compared to
the conventional case where cooling water is used, whereby further
reduction in the size and increase in the cooling efficiency are
achieved compared to conventional ammonia condensing cooling cycles
Sc including a cooling tower and a cooling water pump.
[0050] As shown in FIGS. 2 and 3, the evaporative condenser 100
includes a casing 110, an inclined plate-like refrigerant cooling
portion 120 for cooling and condensing refrigerant R delivered
sequentially after circulating in the ammonia condensing cooling
cycle Sc, an inclined plate-like water spraying portion 130 for
spraying the refrigerant cooling portion 120 with cooling water CW
to cool the refrigerant cooling portion 120, a draft fan 140, an
eliminator 150, a water spraying pump 160, and a water feed pipe
170.
[0051] The casing 110 includes an air inlet 112, an air outlet 114,
and a water collecting tank 116. The air inlet 112 is an opening
for taking in air from outside the casing 110 and provided in a
casing side wall surface of the casing 110. The air outlet 114 is
an opening for discharging air from inside the casing 110 and
provided in a top surface of the casing 110. The water collecting
tank 116 is a bottomed space for storing cooling water CW in the
casing 110 and provided on a casing bottom wall surface of the
casing 110.
[0052] The refrigerant cooling portion 120, the water spraying
portion 130, and the draft fan 140 are installed inside the casing
110. The refrigerant cooling portion 120 consists of an upstream
refrigerant gas supply header 122, a downstream refrigerant liquid
discharge header 124, and multiple condenser coils 126. The
refrigerant cooling portion 120 is provided on a flow passage of
air taken in through the air inlet 112 and discharged through the
air outlet 114. For example, the refrigerant cooling portion 120 is
installed at a position higher than that of the air inlet 112.
[0053] The upstream refrigerant gas supply header 122 is provided
on the upstream side of the refrigerant cooling portion 120 where
refrigerant R delivered from the ammonia condensing cascade
condenser Sa1 of the primary ammonia refrigeration cycle Sa flows
into to serve as a straight pipe provided in a bridge manner at a
high position on the casing side wall surface of the casing 110 to
supply refrigerant gas therethrough.
[0054] The downstream refrigerant liquid discharge header 124 is
provided on the downstream side where refrigerant R flowing out of
the refrigerant cooling portion 120 is sent into the ammonia
condensing cascade condenser Sa1 to serve as a straight pipe
provided in a bridge manner at a low position on the casing side
wall surface of the casing 110 opposed to the upstream refrigerant
gas supply header 122 to discharge refrigerant liquid
therethrough.
[0055] The upstream refrigerant gas supply header 122 and the
downstream refrigerant liquid discharge header 124 have
approximately the same pipe diameter (inside diameter). The
upstream refrigerant gas supply header 122 and the downstream
refrigerant liquid discharge header 124 may be arranged inside or
outside the casing 110.
[0056] Each of the condenser coils 126 is constituted by a straight
pipe. Each of the multiple straight pipes constituting the multiple
condenser coils 126 is in communication with the upstream
refrigerant gas supply header 122 at one end on the upstream side,
while in communication with the downstream refrigerant liquid
discharge header 124 at the other end on the downstream side. The
multiple condenser coils 126 are provided and connected between the
upstream refrigerant gas supply header 122 and the downstream
refrigerant liquid discharge header 124 in a mutually spaced
parallel manner and arranged in an inclined manner with respect to
the horizontal direction. The refrigerant cooling portion 120 then
has an inclined plate-like structure. Thus, longer piping
contributes to the evaporation of cooling water CW in the condenser
coils 126 arranged at least partially in an inclined manner with
respect to the horizontal direction compared to such horizontally
arranged condenser coils as in a refrigerant cooling portion used
in a conventional evaporative condenser, which increases the region
contributing to the evaporation of cooling water CW, that is, the
surface area of the outer peripheral wall surfaces and the region
contributing to the cooling of refrigerant R, that is, the surface
area of the inner peripheral wall surfaces.
[0057] Heat conductivity then increases between the cooling water
CW sprayed from the water spraying portion 130 onto the outer
peripheral wall surfaces of the condenser coils 126 and the
refrigerant R brought close to the inner peripheral wall surfaces
of the condenser coils 126, resulting in an increase in the
efficiency of devolatilization of the refrigerant R.
[0058] The pipe diameter of the condenser coils 126 is smaller than
that of the upstream refrigerant gas supply header 122 and the
downstream refrigerant liquid discharge header 124. This causes air
to flow easily through the clearance gaps between the condenser
coils 126, which can promote the evaporation of cooling water CW
adhering to the outer peripheral wall surfaces of the condenser
coils 126.
[0059] The water spraying portion 130 is provided below the
refrigerant cooling portion 120, i.e., on the windward side. The
water spraying portion 130 consists of a cooling water supply
header 132 and multiple water spraying nozzles 134. The cooling
water supply header 132 is a straight pipe provided in a bridge
manner on the upstream side of the water spraying portion 130 where
cooling water CW is fed from the water spraying pump 160 to supply
the cooling water to the water spraying nozzles 134. The cooling
water supply header 132 may be provided in a bridge manner either
below the upstream refrigerant gas supply header 122 or below the
downstream refrigerant liquid discharge header 124.
[0060] Each of the water spraying nozzles 134 is constituted by a
straight pipe. The nozzles are provided below the condenser coils
126 in the forward direction of ventilation, and arranged in an
inclined manner along the condenser coils 126. The multiple water
spraying nozzles 134 are connected to the cooling water supply
header 132 and arranged in a mutually spaced, parallel, side by
side relationship. The water spraying portion 130 then has an
inclined plate-like structure of a so-called comb form. That is,
the inclined plate-like refrigerant cooling portion 120 and the
inclined plate-like water spraying portion 130 are arranged in an
inclined manner with respect to the horizontal direction, with the
water spraying portion 130 being provided below the refrigerant
cooling portion 120, i.e., on the windward side in parallel side by
side relationship, and at a constant distance therebetween.
[0061] This causes the distance to be constant between the water
spraying nozzles 134 of the water spraying portion 130 and the
condenser coils 126 of the refrigerant cooling portion 120, whereby
cooling water CW sprayed from the water spraying nozzles 134 is
directed evenly and equally toward the lower part of the condenser
coils 126 to adhere to lower portions of the outer surfaces, that
is, the outer peripheral wall surfaces of the condenser coils 126,
to then flow downstream. Also, a larger amount of sprayed cooling
water CW adheres to the lower part of the condenser coils 126,
which promotes generation of, for example, liquid film and/or
droplets on the inner peripheral wall surfaces in the lower part,
that is, in lower portions of the inner peripheral wall surfaces of
the condenser coils 126.
[0062] The straight pipes constituting the water spraying nozzles
134 each have multiple injection ports. The injection ports are
water spraying ports for turning the cooling water CW into a spray,
and face the condenser coils 126. The pipe diameter of the water
spraying nozzles 134 is smaller than that of the cooling water
supply header 132. This causes air to flow easily through the
clearance gaps between the water spraying nozzles 134, and air
passing through the clearance gaps between the condenser coils 126
to be discharged easily through the air outlet 114.
[0063] The draft fan 140 is provided at the air outlet 114. The
eliminator 150 is provided between the refrigerant cooling portion
120 and the draft fan 140, and arranged in an inclined manner along
the refrigerant cooling portion 120 and the water spraying portion
130.
[0064] The eliminator 150 has multiple elements 152. Each of the
elements 152 is installed longitudinally along the condenser coils
126. Thus, misty cooling water CW sprayed from the water spraying
portion 130 not contributing to the cooling of the refrigerant
cooling portion 120 is trapped earlier by the elements 152 of the
eliminator 150, compared to the conventional case where an
eliminator 150 is provided at the air outlet 114 of the casing 110.
Droplets of trapped cooling water CW are collected while flowing
through the elements 152 under their own weight toward the lower
part of the eliminator 150 to be discharged from the casing bottom
wall surface side of the eliminator 150. The droplets flow down
directly into the water collecting tank 116, which is provided on
the bottom wall surface of the casing 110, to be recovered. The
amount of cooling water CW discharged to the outside of the
evaporative condenser 100 with an airflow from the air inlet 112
toward the air outlet 114 generated within the casing 110 by the
draft fan 140 is then reduced, and the amount of consumption of
cooling water CW is thereby also reduced.
[0065] The water spraying pump 160 and the water feed pipe 170 are
provided between the water collecting tank 116 and the cooling
water supply header 132 for circulation of cooling water CW within
the casing.
[0066] An operation of the evaporative condenser 100 according to
the invention, in which gaseous refrigerant Rg (R) supplied
undergoes heat removal to be condensed/devolatilized and the liquid
refrigerant R1 (R) is discharged, will now be described with
reference to FIGS. 2 and 3.
[0067] When the draft fan 140 starts to rotate, air taken through
the air inlet 112 into the casing 110 passes through the
refrigerant cooling portion 120, and is then discharged forcibly
through the air outlet 114.
[0068] Cooling water CW is sent by the water spraying pump 160 from
the water collecting tank 116, through the water feed pipe 170,
into the cooling water supply header 132. The cooling water CW thus
sent into the cooling water supply header 132 flows therethrough
and is branched into the multiple water spraying nozzles 134 and
turned into a spray through the injection ports of the water
spraying nozzles 134 in the forward direction along the direction
of ventilation by the draft fan 140. Since the direction of
ventilation and the direction of spraying are the same, a smaller
amount of power is required to operate the draft fan 140 compared
to the conventional case where the direction of spraying is reverse
of the direction of ventilation. The injection ports of the water
spraying nozzles 134 employ a structure with which droplets in the
form of a mist are generated. These droplets are finer than the
droplets generated in the case of spraying in the reverse
direction, and ensure a cooling effect due to evaporation from the
surfaces of droplets between the injection ports and the condenser
coils 126.
[0069] The sprayed cooling water CW comes into contact with the
outer peripheral wall surfaces of the condenser coils 126. The
contacted cooling water CW is evaporated (vaporized) by flowing air
to remove the latent heat of evaporation from the outer peripheral
wall surfaces of the condenser coils 126. The cooling water CW not
evaporated is recovered by the eliminator 150 or falls in droplets
that are returned to the water collecting tank 116 and reused.
[0070] Gaseous refrigerant Rg delivered to the refrigerant cooling
portion 120 flows into the upstream refrigerant gas supply header
122. The gaseous refrigerant Rg thus flowing into the upstream
refrigerant gas supply header 122 flows therethrough to be branched
into the multiple condenser coils 126. The branched gaseous
refrigerant Rg flows into the pipes of the condenser coils 126 and
flows downward in one direction toward the downstream refrigerant
liquid discharge header 124.
[0071] The condenser coils 126, which have undergone removal of the
latent heat of evaporation, remove heat from a portion of the
down-flowing gaseous refrigerant Rg in proximity to the inner
peripheral wall surfaces of the condenser coils 126. The gaseous
refrigerant Rg thus undergoes heat removal, and is
condensed/devolatilized into liquid refrigerant R1, which adheres
to the inner peripheral wall surfaces of the condenser coils 126 as
a liquid film and/or droplets, for example.
[0072] Here, the condenser coils 126 are arranged in an inclined
manner with respect to the horizontal direction. Thus, when the
gaseous refrigerant Rg undergoes heat removal from the inner
peripheral wall surfaces of the condenser coils 126, while moving
within the pipes of the condenser coils 126, it is cooled and
thereby undergoes removal of the latent heat of condensation. The
gaseous refrigerant is thus condensed/devolatilized to generate,
for example, a liquid film and/or droplets, which stagnate on, and
adhere to, the inner peripheral wall surfaces of the condenser
coils 126. The stagnating and adhering liquid refrigerant R1 flows,
in a small amount, under its own weight, downward without
stagnation within the pipes of the condenser coils 126.
[0073] Since the liquid refrigerant R1 flows downward, the amount
of liquid film and/or droplets of the liquid refrigerant R1
stagnating on and adhering to the inner peripheral wall surfaces of
the condenser coils 126 is constantly small. Since the amount of
stagnating and adhering liquid refrigerant R1 is constantly small,
condensation/devolatilization of the remaining gaseous refrigerant
Rg is also promoted. A refrigerant stagnation preventing feature
thus works in the condenser coils. The stagnation preventing
feature then reduces the amount of stagnation and adherence of the
refrigerant R, whereby the amount of filled refrigerant within the
pipes is minimized, and is smaller than the amount of filled
refrigerant in conventional evaporative condensers.
[0074] Further, the straight pipe portions constituting at least
part of the condenser coils 126 are installed within the region of
spraying of cooling water CW from the water spraying portion 130.
Thus, when the gaseous refrigerant Rg is condensed/devolatilized,
and stagnates on and adheres to the inner peripheral wall surfaces
of the condenser coils 126, the stagnating and adhering liquid
refrigerant R1 flows down faster within the straight pipes, which
are short and inclined at a uniform angle in one direction. The
amount of condensed/devolatilized refrigerant in the condenser
coils 126 with the straight pipe portions constituting at least
part thereof installed within the region of spraying of cooling
water CW from the water spraying portion 130, is small compared to
the amount of condensed/devolatilized refrigerant in condenser
coils having curved pipe portions within this area. The gaseous
refrigerant Rg then comes close to the inner peripheral wall
surfaces of the condenser coils 126 to be cooled efficiently and
condensed/devolatilized into liquid refrigerant R1.
[0075] Liquid refrigerants R1 flowing downward through the
respective multiple condenser coils 126 merge at the downstream
refrigerant liquid discharge header 124. The merged liquid
refrigerant R1 is then sent out of the downstream refrigerant
liquid discharge header 124. The refrigerant R is thus cooled while
flowing downward within the pipes of the condenser coils 126.
[0076] Further, the refrigerant cooling portion 120, which is
arranged in an inclined manner, has a larger entrance area for
ventilation than the conventional case of horizontal arrangement.
For example, provided that the width W (i.e. length in the depth
direction) is constant and the length of a conventional
horizontally arranged plate-like refrigerant cooling portion is L,
if the inclined plate-like refrigerant cooling portion 120
according to the invention is arranged in an inclined manner to
discharge liquid refrigerant R1 at a position vertically lower than
conventional ones by the length 0.7L, the length of the refrigerant
cooling portion 120 according to the invention is obtained by the
Pythagorean theorem as about 1.2L, and the entrance area is about
1.2LW, that is, about 1.2 times, which is calculated as a product
between the length and the width. Here, since the air volume is
calculated as a product between the entrance area and the wind
speed, the thickness of the refrigerant cooling portion 120 or the
ventilation rate is reduced so that air passes through the
refrigerant cooling portion 120 at the same air volume as
conventional condensers. In addition, if the condenser coils of a
conventional evaporative condenser are inclined as they are, the
size and therefore footprint of the evaporative condenser are
reduced.
[0077] The air resistance of the refrigerant cooling portion 120 is
approximately proportional to the squared rate and the thickness of
the refrigerant cooling portion 120. The air resistance of the
refrigerant cooling portion 120 then decreases in the case of
either reducing the thickness of the refrigerant cooling portion
120 or reducing the ventilation rate, which causes the power of the
draft fan 140, and therefore the power consumption, to be reduced,
and also causes the noise due to ventilation through the
refrigerant cooling portion 120 to be reduced.
[0078] As is the case with the refrigerant cooling portion 120, the
water spraying portion 130 and the eliminator 150 are also arranged
in an inclined manner to have a larger entrance area for
ventilation than the conventional case of horizontal arrangement.
Thus, as is the case with the refrigerant cooling portion 120,
since the same performance can be achieved even if the thickness of
the air passage may be reduced, the power of the draft fan 140 for
ventilation through the water spraying portion 130 and the
eliminator 150 is reduced, and the noise due to ventilation through
the condenser coils 126 is also reduced. The evaporative condenser
100 can achieve the same performance as conventional evaporative
condensers, even if reduced in size.
[0079] Although the refrigerant cooling portion 120 has been
described for a one-stage structure in which the condenser coils
126 are provided side by side as shown in FIG. 4A, another
structure may be employed in which the condenser coils are divided
into two or more stages and provided side by side. For example, a
three-stage structure in which the condenser coils are divided into
first-stage condenser coils 126a, second-stage condenser coils
126b, and third-stage condenser coils 126c and provided side by
side, is shown in FIG. 4B. When such a multi-stage structure is
employed, the positional relationship between the stages can employ
a structure with which the effect of condensation/devolatilization
of the refrigerant R flowing into the condenser coils 126 is
produced sufficiently, depending on the ventilation rate of air,
such as a structure in which the coils are provided side by side in
one line in the vertical direction as shown in FIG. 4B or a hounds
tooth structure.
[0080] Radiator fins (not shown) may further be provided on the
condenser coils 126 shown in FIGS. 4A and 4B. Providing the fins
causes the surface area of the outer peripheral wall surfaces of
the condenser coils 126 and therefore the region contributing to
the evaporation of cooling water CW to increase, whereby cooling
water CW adhering to the fins can be evaporated to remove sensible
heat efficiently from gaseous refrigerant Rg delivered to the
condenser coils 126. The fins also allow cooling water CW sprayed
from the water spraying portion 130 to be evaporated completely to
use for cooling the refrigerant R, whereby the eliminator 150 for
recovery of cooling water CW not evaporated can be removed, which
reduces the pressure loss due to the presence of the eliminator
150. It is also possible to increase the ventilation rate of air
and further reduce the load on the draft fan 140 for generating an
airflow to reduce the power consumption of the draft fan 140.
[0081] The thus arranged evaporative condenser 100 according to the
first example of the invention includes the refrigerant cooling
portion 120 for cooling and condensing refrigerant R delivered
sequentially after circulating in the ammonia condensing cooling
cycle Sc, the water spraying portion 130 for spraying the
refrigerant cooling portion 120 with cooling water CW to cool the
refrigerant cooling portion 120, the casing 110 having the air
inlet 112 for taking in and the air outlet 114 for discharging air
used for evaporating cooling water CW sprayed from the water
spraying portion 130, and the draft fan 140 for generating an
airflow from the air inlet 112 to the air outlet 114 inside the
casing 110. The refrigerant cooling portion 120 has the condenser
coils 126 arranged in an inclined manner with respect to the
horizontal direction to cool the refrigerant R while causing the
refrigerant R to flow therethrough downward, and the water spraying
portion 130 has multiple water spraying nozzles 134 arranged in an
inclined manner along the condenser coils 126 to spray the
condenser coils 126 with the cooling water, whereby gaseous
refrigerant Rg delivered sequentially after circulating in the
ammonia condensing cooling cycle Sc is devolatilized efficiently, a
larger amount of cooling water CW sprayed from the water spraying
portion 130 is evaporated by air taken into the casing 110 so that
more latent heat of evaporation is removed from the condenser coils
126, and more heat is removed from the gaseous refrigerant Rg to
the inner peripheral wall surfaces of the condenser coils 126 so
that the gaseous refrigerant Rg can be cooled efficiently and
condensed/devolatilized into liquid refrigerant R1.
[0082] Further, the refrigerant cooling portion 120 has the
upstream refrigerant gas supply header 122 on the upstream side and
the downstream refrigerant liquid discharge header 124 on the
downstream side of the condenser coils 126, and the multiple
condenser coils 126 are provided side by side in parallel with one
another between the upstream refrigerant gas supply header 122 and
the downstream refrigerant liquid discharge header 124. This allows
the gaseous refrigerant Rg to be cooled efficiently and
condensed/devolatilized into liquid refrigerant R1.
[0083] Further, the water spraying portion 130 is provided below
the condenser coils 126 in the forward direction of ventilation and
has the multiple water spraying nozzles 134 arranged in an inclined
manner along the condenser coils 126 to spray the condenser coils
126 with cooling water CW. This can shorten the time of stagnation
and adherence of the liquid refrigerant R1. Further, since the
eliminator 150, which is provided between the refrigerant cooling
portion 120 and the draft fan 140 (and is also located between the
water spraying portion 120 and the draft fan), is arranged in an
inclined manner along the refrigerant cooling portion 120 and the
water spraying portion 130, it is possible to reduce the amount of
consumption of the cooling water CW. Further, if each of the
upstream refrigerant gas supply header 122 and the downstream
refrigerant liquid discharge header 124 of the refrigerant cooling
portion 120 is provided with a connection pipe, and the upstream
refrigerant gas supply header 122 and the downstream refrigerant
liquid discharge header 124 of adjacent refrigerant cooling
portions 120 are connected, the evaporative condenser is adaptive
to the condensation load of the refrigeration equipment and it is
possible to achieve a scale-dependent condensation load by
increasing or decreasing the number of connections, exhibiting a
tremendous effect such as reduction in the initial cost for
development of refrigeration equipment.
[0084] Next will be described an evaporative condenser 200
according to a second example of the invention based on FIGS. 5 to
7. Here, FIG. 5 is a schematic front perspective view of the
evaporative condenser according to the second example of the
invention, FIG. 6 is a cross-sectional view through the section
plane indicated by reference signs 6-6 in FIG. 5, and FIG. 7 is a
conceptual diagram of the evaporative condenser according to the
second example of the invention with a cooling water clarifying
portion connected thereto.
[0085] Since the evaporative condenser 200 according to the second
example is achieved by modifying the form of the casing 110, the
refrigerant cooling portion 120, and the water spraying portion 130
in the above-mentioned evaporative condenser 100 according to the
first example and common with the evaporative condenser 100
according to the first example in the basic structure and principle
of operation, the common features are designated by reference signs
in the 200s but sharing in common the last two digits.
[0086] As shown in FIGS. 5 and 6, the evaporative condenser 200
according to the second example of the invention includes a casing
210, an inclined plate-like refrigerant cooling portion 220 for
cooling and condensing refrigerant R, an inclined plate-like water
spraying portion 230 for spraying the refrigerant cooling portion
220 with cooling water CW to cool the refrigerant cooling portion
220, a draft fan 240, an eliminator 250, a water spraying pump 260,
a water feed pipe 270, and a cooling water clarifying portion
280.
[0087] The casing 210 consists of a first air inlet 212a, a second
air inlet 212b, an air outlet 214, and a water collecting tank 216.
The first air inlet 212a and the second air inlet 212b are openings
for taking in air from outside the casing 210 and provided in a set
of opposed casing side wall surfaces of the casing 210. The air
outlet 214 is an opening for discharging air from inside the casing
210 and provided in a top surface of the casing 210.
[0088] The refrigerant cooling portion 220 consists of a first
upstream refrigerant gas supply header 222a, a second upstream
refrigerant gas supply header 222b, a downstream refrigerant liquid
discharge header 224, first condenser coils 226a, and second
condenser coils 226b. The first upstream refrigerant gas supply
header 222a is a straight pipe provided on the upstream side of the
refrigerant cooling portion 220 and provided in a bridge manner at
a high position adjacent the casing side wall surface of the casing
210. The second upstream refrigerant gas supply header 222b is a
straight pipe provided on the upstream side of the refrigerant
cooling portion 220 and provided in a bridge manner at a high
position adjacent the casing side wall surface of the casing 210
opposed to the first upstream refrigerant gas supply header 222a.
The downstream refrigerant liquid discharge header 224 is a
straight pipe provided on the downstream side of the refrigerant
cooling portion 220 and provided in a bridge manner at a low
position in the casing bottom wall surface opposite the air outlet
214.
[0089] Each of the first condenser coils 226a and each of the
second condenser coils 226b is constituted by a straight pipe. The
multiple first condenser coils 226a are provided and connected
between the first upstream refrigerant gas supply header 222a and
the downstream refrigerant liquid discharge header 224 in a
mutually spaced parallel manner and arranged in an inclined manner
from an upper part of the casing side wall surface toward the
casing bottom wall surface opposed to the air outlet 214. The
multiple second condenser coils 226b are provided and connected
between the second upstream refrigerant gas supply header 222b and
the downstream refrigerant liquid discharge header 224 in a
mutually spaced parallel manner and arranged in an inclined manner
from an upper part of the casing side wall surface of the casing
210 opposed to the first upstream refrigerant gas supply header
222a toward the casing bottom wall surface opposed to the air
outlet 214. The refrigerant cooling portion 220 then has a V form,
a U form, or the like in cross-sectional view, including two
inclined plates arranged in a downward-inclined manner on opposed
side wall surfaces of the casing 210.
[0090] The water spraying portion 230 is provided below the
refrigerant cooling portion 220, i.e., on the windward side. The
water spraying portion 230 consists of a cooling water supply
header 232, first water spraying nozzles 234a, and second water
spraying nozzles 234b. The cooling water supply header 232 is a
straight pipe provided on the upstream side of the water spraying
portion 230 and provided in a bridge manner at a position well
below the upper part of the casing 210. Cooling water CW is fed to
the water supply header 232 from the water spraying pump 260.
[0091] Each of the first water spraying nozzles 234a and each of
the second water spraying nozzles 234b is constituted by a straight
pipe. The multiple first water spraying nozzles 234a are installed
below and along the first condenser coils 226a in the forward
direction of ventilation in a mutually spaced parallel manner and
arranged in an inclined manner from the side wall surface toward
the casing bottom wall surface opposed to the air outlet 214. The
multiple second water spraying nozzles 234b are similarly installed
below and along the second condenser coils 226b in the forward
direction of ventilation and arranged in an inclined manner from
the side wall surface toward the casing bottom wall surface opposed
to the air outlet 214. The second water spraying nozzles 234b are
in opposed relationship to the first water spraying nozzles 234a.
The water spraying portion 230 then has a structure of a V form, a
U form, or the like in a cross-sectional view, including two
inclined plates of a so-called comb form arranged below and along
the refrigerant cooling portion 220.
[0092] Since the flow rate of air traversing the first condenser
coils 226a and the second condenser coils 226b is higher near the
casing bottom wall surface opposed to the air outlet 214 than the
flow rate of air near the side wall surface of the casing 210, a
larger amount of air evaporates cooling water CW adhering to the
outer peripheral wall surfaces of the first condenser coils 226a
and the second condenser coils 226b closer to the downstream side
of the first condenser coils 226a and the second condenser coils
226b. Further, compared to the case where air passes through
horizontally arranged condenser coils in an intersecting manner at
a near-right angle as in the refrigerant cooling portion used in
conventional evaporative condensers, the air thus passes through
the first condenser coils 226a and the second condenser coils 226b,
which are arranged in an inclined manner with respect to the
horizontal direction, in an intersecting manner at a smaller angle,
which widens the clearance gap between adjacent first and second
condenser coils 226a and 226b through which the air passes and
reduces the pressure loss, which resists the airflow passing
through the clearance gap, according to the widening of the
clearance gap. Thus it is possible to increase the wind speed up to
the same pressure loss as in the case where the conventional
arrangement of condenser coils is used.
[0093] For example, provided that the width W (i.e., length in the
depth direction) is constant and the length of a conventional
horizontally arranged plate-like refrigerant cooling portion is L,
if the inclined plate-like refrigerant cooling portion 220
according to the invention is arranged in a downward-inclined
manner by 60 degrees with respect to the horizontal direction to
discharge liquid refrigerant R1 at a position vertically lower than
conventional ones by a length 1.7L, that is, arranged to form two
sides of an inverted equilateral triangle, the length of the
refrigerant cooling portion 220 according to the invention is
obtained by the Pythagorean theorem as about 2L, and the entrance
area is about 2LW, that is, about two times, which is calculated as
a product of the length and the width. Here, since the air volume,
if constant, is calculated as a product of the entrance area and
the wind speed, the thickness of the refrigerant cooling portion
220 can be reduced by half so that air passes through the
refrigerant cooling portion 220 at the same air volume as in
conventional condensers.
[0094] Further, since the refrigerant cooling portion 220 is
opposed to a pair of casing side wall surfaces, the entrance area
for ventilation is doubled and thereby the wind speed is reduced by
half. Here, the air resistance of the refrigerant cooling portion
220 is approximately proportional to the squared speed and the
thickness of the refrigerant cooling portion 220. Then, since the
ventilation rate and the thickness of the refrigerant cooling
portion 220 are each halved, the air resistance of the refrigerant
cooling portion 220 is reduced to one eighth, which allows the
power consumption of the draft fan 240 to be reduced significantly.
In addition, since the ventilation rate is halved, the noise due to
ventilation through the refrigerant cooling portion 220 is also
reduced.
[0095] The eliminator 250 is provided between the refrigerant
cooling portion 220 and the draft fan 240, and arranged in an
inclined manner from the casing side wall surface toward the casing
bottom wall surface opposed to the air outlet 214 along the
refrigerant cooling portion 220 and the water spraying portion 230
to form a V shape (recessed form). Thus, misty cooling water CW
sprayed from the water spraying portion 230, and not contributing
to the cooling of the refrigerant cooling portion 220, is trapped
earlier by the eliminator 250, compared to the conventional case
where an eliminator 250 is provided at the air outlet 214 of the
casing 210.
[0096] As an alternative, the first condenser coils 226a may be
constituted by multiple straight pipes arranged in a
downward-inclined manner from near the top surface toward a casing
side wall surface and the second condenser coils 226b may be
constituted by multiple straight pipes arranged in a
downward-inclined manner from near the top surface toward a casing
side wall surface opposed to the casing side wall surface to which
the first condenser coils 226a are directed. The water spraying
nozzles may be arranged below or above the respective condenser
coils 226 on the windward or leeward side.
[0097] As shown in FIG. 7, the cooling water clarifying portion 280
is a cooling water clarifying system for clarifying cooling water
CW trapped and recovered by the eliminator 250 and returned to the
water collecting tank 216. The cooling water clarifying portion 280
is provided between the water collecting tank 216 and the cooling
water supply header 232 of the water spraying portion 230. The
cooling water clarifying portion 280 consists of a filtering tank
282, an adsorption tank 284, a permeation membrane tank 286, a
freshwater tank 288, a circulation pump 289, and piping for
sequential connection thereof.
[0098] The filtering tank 282 is filled with filtering medium 282a.
The adsorption tank 284 is filled with adsorbent 284a. The
permeation membrane tank 286 is filled with permeation membranes
286a. The permeation membrane tank 286 is further provided with a
water feed pipe for feeding cooling water CW to the freshwater tank
288 as well as a drain pipe 286p for returning cooling water CW
directly to the water collecting tank 216.
[0099] The freshwater tank 288 is a water storage tank having a
storage capacity according to the user requirement for cooling
water CW in the evaporative condenser 200. The freshwater tank 288
is further provided with a water feed pipe for feeding cooling
water CW to the circulation pump 289 as well as an overflow pipe
288p for returning cooling water CW directly to the water
collecting tank 216.
[0100] The filtering tank 282 is arranged to filter air dust and
the like incorporated in cooling water CW that is delivered from
the water collecting tank 216. The adsorption tank 284 is arranged
to remove, for example, toxic gas and/or corrosive gas incorporated
from the air into cooling water CW that is delivered from the
filtering tank 282.
[0101] The permeation membrane tank 286 is arranged to filter
impurities other than water, such as ions and salts, incorporated
in cooling water CW that is delivered from the adsorption tank 284.
If the cooling water CW does not reach a quality suitable for use
even after passing through the permeation membrane tank 286, the
cooling water CW is returned directly to the water collecting tank
216 through the drain pipe 286p.
[0102] The freshwater tank 288 is arranged to store cooling water
CW that is delivered from the permeation membrane tank 286. If the
storage of the freshwater tank 288 exceeds a certain amount, the
cooling water CW is returned from the freshwater tank 288 directly
to the water collecting tank 216 through the overflow pipe 288p,
whereby the storage can be kept at constant and/or the
concentration of, for example, impurities and/or toxic gas
dissolved in the cooling water CW can be lowered to reduce the load
on the cooling water clarifying portion 280. The cooling water CW
stored in the freshwater tank 288 is then pumped by the circulation
pump 289 to the cooling water supply header 232 of the water
spraying portion 230 and sprayed therefrom.
[0103] The cooling water clarifying portion 280 thus removes, from
the cooling water CW, impurities that may contaminate and/or erode
the refrigerant cooling portion 220, the water spraying portion
230, and the like installed within the casing 210, such as
impurities concentrated through spraying and dust and/or toxic gas
incorporated from the air during spraying. The cooling water
clarifying portion 280 has a timer function for sensing a change in
the quality of cooling water CW and, when or before the water
quality becomes inadequate for use in the evaporative condenser
200, periodically clarifies and partially or wholly replaces the
cooling water CW. This allows the cooling water clarifying portion
280 to periodically remove impurities from the cooling water CW to
keep the cooling water CW at a water quality suitable for use.
[0104] The filtering tank 282, the adsorption tank 284, and the
permeation membrane tank 286 may be omitted if not required,
depending on the quality of the cooling water CW. Further, the
freshwater tank 288 may be omitted, and the cooling water CW
clarified through the permeation membrane tank 286 may be drained
to the water collecting tank 216. Furthermore, some of the tanks
may be integrated to eliminate the need for interconnecting
piping.
[0105] The replenishment of cooling water CW employs a method of
water feeding to the water collecting tank 216 through a water feed
pipe 290 as shown in FIG. 6, but may employ a method of water
feeding via the cooling water clarifying system, such as a method
of water feeding through connection of the water feed pipe 290 to
the piping from the water spraying pump 260 to the filtering tank
282 or a method of water feeding through direct connection to the
filtering tank 282.
[0106] In the thus arranged evaporative condenser 200 according to
the second example of the invention, the first air inlet 212a and
the second air inlet 212b are provided in opposed side wall
surfaces of the casing 210, the air outlet 214 is provided in the
top surface of the casing 210. The first condenser coils 226a and
the second condenser coils 226b are arranged in an inclined manner
from the upper part of the casing side wall surface toward the
casing bottom wall surface opposed to the air outlet 214, whereby
gaseous refrigerant Rg can be cooled and condensed/devolatilized
into liquid refrigerant R1 more efficiently on the downstream side
than on the upstream side of the first condenser coils 226a and the
second condenser coils 226b. Thus, the cooling of refrigerant can
be promoted.
[0107] Further, since the water spraying portion 230 is connected
to the cooling water clarifying portion 280 for clarifying the
cooling water CW, which improves the quality of the cooling water
CW and prevents performance degradation of the evaporative
condenser 200, exhibiting a tremendous effect such as reduction in
the frequency of maintenance.
[0108] Next will be described an evaporative condenser 300
according to a third example of the invention based on FIGS. 8 to
10. Here, FIG. 8 is a schematic front perspective view of the
evaporative condenser 300 according to the third example of the
invention, FIG. 9 is a cross-sectional view through the section
plane indicated by reference signs 9-9 in FIG. 8, and FIG. 10 is a
cross-sectional view through the section plane indicated by
reference signs 10-10 in FIG. 8.
[0109] Since the evaporative condenser 300 according to the third
example is achieved by modifying the position of the refrigerant
cooling portion 120, the water spraying portion 130, and the
eliminator 150 in the above-mentioned evaporative condenser 100
according to the first example, and otherwise has a basic structure
and principle of operation in common with the evaporative condenser
100 according to the first example, the common matters are
designated by reference signs in the 300s, but sharing in common
the last two digits.
[0110] As shown in FIGS. 8 and 9, the evaporative condenser 300
includes a casing 310, an inclined plate-like refrigerant cooling
portion 320 for cooling and condensing refrigerant R delivered
sequentially after circulating in the ammonia condensing cooling
cycle Sc, an inclined plate-like water spraying portion 330 for
spraying the refrigerant cooling portion 320 with cooling water CW
to cool the refrigerant cooling portion 320, a draft fan 340, an
eliminator 350, a water spraying pump 360, and a water feed pipe
370.
[0111] The refrigerant cooling portion 320, the water spraying
portion 330, and the draft fan 340 are installed inside the casing
310. The refrigerant cooling portion 320 consists of an upstream
refrigerant gas supply header 322, a downstream refrigerant liquid
discharge header 324, and condenser coils 326. The condenser coils
326 are provided between the upstream refrigerant gas supply header
322 and the downstream refrigerant liquid discharge header 324, and
are arranged in an inclined manner with respect to the horizontal
direction. The refrigerant cooling portion 320 then has an inclined
plate-like structure.
[0112] The water spraying portion 330 is provided above the
refrigerant cooling portion 320, i.e. on the leeward side. The
water spraying portion 330 consists of a cooling water supply
header 332 and water spraying nozzles 334.
[0113] The water spraying nozzles 334 are constituted by multiple
straight pipes, provided above the condenser coils 326 in the
reverse direction of ventilation, and arranged in an inclined
manner along the condenser coils 326. The multiple straight pipes
constituting the water spraying nozzles 334 are arranged side by
side in parallel with one another, having an inclined plate-like
structure of a so-called comb form. That is, the inclined
plate-like refrigerant cooling portion 320 and the inclined
plate-like water spraying portion 330 are arranged in an inclined
manner with respect to the horizontal direction, with the water
spraying portion 330 being provided above the refrigerant cooling
portion 320, i.e., on the leeward side in parallel, side-by-side
relationship, at a constant distance therebetween. This makes the
direction of cooling water CW sprayed from the water spraying
portion 330 opposite to the direction of air flow, and thus results
in a high contact speed between the cooling water CW and the air,
resulting in an increase in the cooling effect of the cooling water
itself.
[0114] The eliminator 350 is provided between the draft fan 340 and
the water spraying portion 330 to prevent droplet cooling water CW
accompanying the flow of air discharged through the air outlet 314
from scattering outside the casing 310 through the air outlet
314.
[0115] In the thus arranged evaporative condenser 300 according to
the third example of the invention, the water spraying portion 330
is provided above the condenser coils 326 of the refrigerant
cooling portion 320 and the multiple water spraying nozzles 334 are
arranged in an inclined manner along the condenser coils 326 to
spray the condenser coils 326 with cooling water CW, whereby the
cooling water CW sprayed from the water spraying portion 330 is
evaporated while moving downward on the outer peripheral wall
surfaces of the condenser coils 326. The outer peripheral wall
surfaces of the condenser coils 326 are thus utilized
effectively.
[0116] Next will be described an evaporative condenser 400
according to a fourth example of the invention based on FIGS. 11
and 12. Here, FIG. 11 is a schematic front perspective view of the
evaporative condenser 400 according to the fourth example of the
invention, and FIG. 12 is a cross-sectional view through the
section plane indicated by reference signs 12-12 in FIG. 11.
[0117] Since the evaporative condenser 400 according to the fourth
example is achieved by modifying the form of the casing 110, the
refrigerant cooling portion 120, the water spraying portion 130,
and the eliminator 150 and the position of the refrigerant cooling
portion 120 and the water spraying portion 130 in the
above-mentioned evaporative condenser 100 according to the first
example, and otherwise has a basic structure and principle of
operation in common with the evaporative condenser 100 according to
the first example, the common matters are designated by reference
signs in the 400s, but sharing in common the last two digits.
[0118] As shown in FIGS. 11 and 12, the evaporative condenser 400
according to the fourth example of the invention includes a casing
410, an inclined plate-like refrigerant cooling portion 420 for
cooling and condensing refrigerant R, an inclined plate-like water
spraying portion 430 for spraying the refrigerant cooling portion
420 with cooling water CW to cool the refrigerant cooling portion
420, a draft fan 440, an eliminator 450, a water spraying pump 460,
and a water feed pipe 470. The casing 410 consists of a first air
inlet 412a, a second air inlet 412b, an air outlet 414, and a water
collecting tank 416.
[0119] The first air inlet 412a and the second air inlet 412b are
openings for taking in air from outside the casing 410 and provided
in a set of opposed casing side wall surfaces of the casing 410.
The air outlet 414 is an opening for discharging air from inside
the casing 410 and provided in a top surface of the casing 410.
[0120] The refrigerant cooling portion 420 consists of a first
upstream refrigerant gas supply header 422a, a second upstream
refrigerant gas supply header 422b, a first downstream refrigerant
liquid discharge header 424a, a second downstream refrigerant
liquid discharge header 424b, first condenser coils 426a, and
second condenser coils 426b. The first upstream refrigerant gas
supply header 422a is a straight pipe provided on the upstream side
of the refrigerant cooling portion 420 and provided in a bridge
manner at a high position adjacent a side wall surface of the
casing 410.
[0121] The second upstream refrigerant gas supply header 422b is a
straight pipe provided on the upstream side of the refrigerant
cooling portion 420 and provided in a bridge manner at a high
position adjacent the side wall surface of the casing 410 opposed
to the side wall surface adjacent the first upstream refrigerant
gas supply header 422a. The first downstream refrigerant liquid
discharge header 424a and the second downstream refrigerant liquid
discharge header 424b are straight pipes provided on the downstream
side of the refrigerant cooling portion 420 and provided in a
bridge manner at a low position adjacent the casing bottom wall
surface opposed to the air outlet 414.
[0122] Each of the first condenser coils 426a and the second
condenser coils 426b is constituted by a straight pipe. The
multiple first condenser coils 426a are provided and connected
between the first upstream refrigerant gas supply header 422a and
the first downstream refrigerant liquid discharge header 424a in a
mutually spaced parallel manner, and arranged in an inclined manner
from the casing side wall surface toward the casing bottom wall
surface opposed to the air outlet 414. The multiple second
condenser coils 426b are similarly provided and connected between
the second upstream refrigerant gas supply header 422b and the
second downstream refrigerant liquid discharge header 424b in a
mutually spaced parallel manner, and arranged in an inclined manner
from the casing side wall surface of the casing 410 opposed to the
side wall surface adjacent the first upstream refrigerant gas
supply header 422a toward the casing bottom wall surface opposed to
the air outlet 414. The refrigerant cooling portion 420 then has a
structure of a V form, a U form, or the like in a cross-sectional
view, including two inclined plates arranged in an inclined manner
on opposed side wall surfaces of the casing 410.
[0123] The water spraying portion 430 is provided above the
refrigerant cooling portion 420, i.e. on the leeward side. The
water spraying portion 430 consists of a first cooling water supply
header 432a, a second cooling water supply header 432b, first water
spraying nozzles 434a, and second water spraying nozzles 434b. The
first cooling water supply header 432a is a straight pipe provided
on the upstream side of the water spraying portion 430 where
cooling water CW is fed from the water spraying pump 460 and
provided in a bridge manner at a high position adjacent the casing
side wall surface of the casing 410. The second cooling water
supply header 432b is a straight pipe provided on the upstream side
of the water spraying portion 430 where cooling water CW is fed
from the water spraying pump 460 and provided in a bridge manner at
a high position adjacent the side wall surface of the casing 410
opposed to the side wall surface adjacent the first cooling water
supply header 432a.
[0124] The first water spraying nozzles 434a and the second water
spraying nozzles 434b are each constituted by a straight pipe. The
multiple first water spraying nozzles 434a are installed above and
along the first condenser coils 426a in the reverse direction of
ventilation, and arranged in an inclined manner from the casing
side wall surface toward the casing bottom wall surface opposed to
the air outlet 414. The multiple second water spraying nozzles 434b
are installed above and along the second condenser coils 426b in
the reverse direction of ventilation, and arranged in an inclined
manner from the casing side wall surface of the casing 410 opposed
to the side wall surface adjacent the first water spraying nozzles
434a toward the casing bottom wall surface opposed to the air
outlet 414. The water spraying portion 430 then has a structure of
a V form, a U form, or the like in a cross-sectional view,
including two inclined plates of a so-called comb form arranged
above and along the refrigerant cooling portion 420.
* * * * *