US20180299168A1

US20180299168A1 - Evaporative condenser and refrigeration system equipped with said evaporative condenser

Info

Publication number: US20180299168A1
Application number: US15/767,679
Authority: US
Inventors: Hidetoshi Kaneo
Original assignee: Hidetoshi Kaneo
Current assignee: Hidetoshi Kaneo
Priority date: 2015-10-28
Filing date: 2016-10-14
Publication date: 2018-10-18
Also published as: JP6574262B2; JPWO2017073367A1; WO2017073087A1; CN107923676A

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.

Description

FIELD OF THE INVENTION

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

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.
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.
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.
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.
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.
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

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.
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.
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.
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.
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.
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.
In a sixth aspect, the invention further solves the above-mentioned problems with a refrigeration system having an evaporative condenser.

SUMMARY OF THE INVENTION

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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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

FIG. 1 is a conceptual diagram illustrating a refrigeration system that uses an evaporative condenser of the invention.

FIG. 2 is a schematic front perspective view of an evaporative condenser according to a 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 in the evaporative condenser of the invention.

FIG. 4B shows a variation of the refrigerant cooling portion in the evaporative condenser of the invention.

FIG. 5 is a schematic front perspective view of an evaporative condenser according to a 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.

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.

FIG. 8 is a schematic front perspective view of an evaporative condenser according to a 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.

FIG. 10 is a cross-sectional view through the section plane indicated by reference signs 10-10 in FIG. 8.

FIG. 11 is a schematic front perspective view of an evaporative condenser according to a fourth example of the invention.

FIG. 12 is a cross-sectional view through the section plane indicated by reference signs 12-12 in FIG. 11.

DETAILED DESCRIPTION

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.
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 134 a). Any refrigerant may be used as long as condensed/devolatilized to be liquid within the pipes of condenser coils of the evaporative condenser.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 126 a, second-stage condenser coils 126 b, and third-stage condenser coils 126 c 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.
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.
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.
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.
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.
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.
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 200 s but sharing in common the last two digits.
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.
The casing 210 consists of a first air inlet 212 a, a second air inlet 212 b, an air outlet 214, and a water collecting tank 216. The first air inlet 212 a and the second air inlet 212 b 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.
The refrigerant cooling portion 220 consists of a first upstream refrigerant gas supply header 222 a, a second upstream refrigerant gas supply header 222 b, a downstream refrigerant liquid discharge header 224, first condenser coils 226 a, and second condenser coils 226 b. The first upstream refrigerant gas supply header 222 a 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 222 b 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 222 a. 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.
Each of the first condenser coils 226 a and each of the second condenser coils 226 b is constituted by a straight pipe. The multiple first condenser coils 226 a are provided and connected between the first upstream refrigerant gas supply header 222 a 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 226 b are provided and connected between the second upstream refrigerant gas supply header 222 b 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 222 a 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.
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 234 a, and second water spraying nozzles 234 b. 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.
Each of the first water spraying nozzles 234 a and each of the second water spraying nozzles 234 b is constituted by a straight pipe. The multiple first water spraying nozzles 234 a are installed below and along the first condenser coils 226 a 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 234 b are similarly installed below and along the second condenser coils 226 b 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 234 b are in opposed relationship to the first water spraying nozzles 234 a. 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.
Since the flow rate of air traversing the first condenser coils 226 a and the second condenser coils 226 b 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 226 a and the second condenser coils 226 b closer to the downstream side of the first condenser coils 226 a and the second condenser coils 226 b. 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 226 a and the second condenser coils 226 b, 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 226 a and 226 b 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.
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.
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.
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.
As an alternative, the first condenser coils 226 a 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 226 b 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 226 a are directed. The water spraying nozzles may be arranged below or above the respective condenser coils 226 on the windward or leeward side.
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.
The filtering tank 282 is filled with filtering medium 282 a. The adsorption tank 284 is filled with adsorbent 284 a. The permeation membrane tank 286 is filled with permeation membranes 286 a. 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 286 p for returning cooling water CW directly to the water collecting tank 216.
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 288 p for returning cooling water CW directly to the water collecting tank 216.
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.
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 286 p.
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 288 p, 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.
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.
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.
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.
In the thus arranged evaporative condenser 200 according to the second example of the invention, the first air inlet 212 a and the second air inlet 212 b 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 226 a and the second condenser coils 226 b 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 226 a and the second condenser coils 226 b. Thus, the cooling of refrigerant can be promoted.
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.
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.
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 300 s, but sharing in common the last two digits.
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.
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.
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.
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.
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.
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.
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.
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 400 s, but sharing in common the last two digits.
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 412 a, a second air inlet 412 b, an air outlet 414, and a water collecting tank 416.
The first air inlet 412 a and the second air inlet 412 b 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.
The refrigerant cooling portion 420 consists of a first upstream refrigerant gas supply header 422 a, a second upstream refrigerant gas supply header 422 b, a first downstream refrigerant liquid discharge header 424 a, a second downstream refrigerant liquid discharge header 424 b, first condenser coils 426 a, and second condenser coils 426 b. The first upstream refrigerant gas supply header 422 a 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.
The second upstream refrigerant gas supply header 422 b 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 422 a. The first downstream refrigerant liquid discharge header 424 a and the second downstream refrigerant liquid discharge header 424 b 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.
Each of the first condenser coils 426 a and the second condenser coils 426 b is constituted by a straight pipe. The multiple first condenser coils 426 a are provided and connected between the first upstream refrigerant gas supply header 422 a and the first downstream refrigerant liquid discharge header 424 a 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 426 b are similarly provided and connected between the second upstream refrigerant gas supply header 422 b and the second downstream refrigerant liquid discharge header 424 b 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 422 a 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.
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 432 a, a second cooling water supply header 432 b, first water spraying nozzles 434 a, and second water spraying nozzles 434 b. The first cooling water supply header 432 a 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 432 b 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 432 a.
The first water spraying nozzles 434 a and the second water spraying nozzles 434 b are each constituted by a straight pipe. The multiple first water spraying nozzles 434 a are installed above and along the first condenser coils 426 a 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 434 b are installed above and along the second condenser coils 426 b 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 434 a 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.

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.