RU2703597C1 - Method of cooling medium in outboard equipment and shipboard cooler - Google Patents

Abstract

FIELD: shipbuilding.

SUBSTANCE: group of inventions relates to shipboard systems, in particular to marine outboard equipment, and can be used on habitable deep water vehicles. Method of cooling medium in overboard equipment includes supply of cooled medium into inter-tube space of heat exchange unit and forced supply of cooling medium (outboard water) through pipes of heat exchange unit. Outflow water coming from the pipes is directed to the inlet of the desalination unit, in which it is desalinated on membrane desalination elements, then the brine is dropped over the board, and desalinated water is used. Cooling is performed mainly at outboard pressure of not less than osmotic pressure of sea water. Ship outboard cooler is made in the form of a multifunctional module, in which a desalting unit is arranged coaxially to a heat exchange unit. Desalination block housing is docked by its ends to the covers, also in the cavity of the desalting unit housing there is at least one membrane desalination element with a central collector connected to the desalinated water discharge nozzle. On the section of the desalting unit housing within the cover cavity without the branch pipes there are through holes with the condition that the total flow section of the holes is not less than the flow passage cross-section of the inlet of outboard water.

EFFECT: use of the declared group of inventions provides higher efficiency of the outboard equipment operation due to expansion of its functional capabilities, use of off-shore pressure as an energy source, utilization of waste heat and neutralization of "thermal trace" left by the outboard cooler, and damping of vibration.

3 cl, 2 dwg

Description

The group of inventions relates to the field of ship systems, in particular to shipboard equipment and can be used on inhabited deep-sea vehicles (GVA), for example, in submarines.

There is a method of cooling the medium (water, oil, condensate, etc.) in a ship's outboard cooler (S. N. Tkach. Study of the influence of operational and structural parameters of the outboard cooler on heat transfer in the annulus // Bulletin of the State University of the Sea and River Fleet named after Admiral C .O. Makarova, 2017, T. 9, No. 5, pp. 1040-1050). Cooled medium is pumped through the pipe cavities of the outboard cooler located in the side box of the surface vessel and the outboard water is naturally circulated in the side box. The cooling process is due to convective heat transfer. The method is ineffective in relation to heat removal and is not suitable for operating conditions of the GVA at great depths under high hydrostatic pressure.

A known method of cooling the environment in the ship's outboard cooler type "pipe in pipe" according to copyright certificate No. 467218, publ. 04/15/1975 (authors V.A. Andreev, I.F. Zhukov, V.V. Sergeev, E.A. Shklyar). The method is implemented as follows: the cooled medium is forcibly (under the pressure of the pump) pumped inside the pipes forming the tube, and outside the tube they are washed by an upward flow of sea water due to the “thermal traction”, which ensures cooling of the medium. The disadvantage of this method is the low efficiency of the cooling process due to the low speed of the upward flow of sea water.

The closest analogue of the proposed technical solution, adopted as a prototype, is a method of cooling the environment in a shipboard pipe-in-pipe outboard cooler according to copyright certificate No. 472068, publ. 05/30/1975 (authors: V.A. Andreev, I.F. Zhukov, V.V. Sergeev, E.A. Shklyar). The method consists in the fact that the cooled medium is forcibly pumped through a pipe of a larger diameter, and the coolant (sea water) is also forced to be pumped through a pipe of a smaller diameter. When exiting a pipe of a smaller diameter, sea water is thrown overboard.

The disadvantage of the prototype method is its low efficiency due to the fact that:

- utilization of “waste” heat is not provided for: the flow of sea water heated in the cooler is thrown overboard;

- it is not envisaged to use outboard pressure as potential energy for performing “associated” work without additional external costs;

-heated seawater when discharged overboard creates a “thermal footprint”, unmasking the outboard cooler and, accordingly, GWA;

- the method provokes increased noise and vibration that occur when pumping water through the pipes of the cooler.

Also known devices for implementing methods of cooling the environment in marine equipment.

Known marine outboard heat exchangers used on surface vessels for cooling working fluids: water, oil, condensate, etc. (S.N. Tkach. Investigation of the effect of operating and structural parameters of an outboard cooler on heat transfer in the annulus // Bulletin of the State University of Marine and River Fleet named after Admiral S.O. Makarov, 2017, T. 9, No. 5, pp. 1040-1050). The heat exchange process in such devices is due to the natural circulation of sea water in the so-called “warm box”, placed in the sea side of the surface vessel. Such technical solutions are not suitable for the conditions of operation of GVA at great depths under high hydrostatic pressure.

Known shipboard cooler according to copyright certificate No. 467218, publ. 04/15/1975 (authors V.A. Andreev, I.F. Zhukov, V.V. Sergeev, E.A. Shklyar). The cooler includes a heat exchanger block housing with a package of heat exchanger pipes fixed in tube boards, pipes for supplying and discharging a cooled medium, as well as pipes for entering and leaving sea water. The cooler works on the principle of natural circulation of sea water with different densities (the principle of "thermal traction") around the heat exchange pipes. The disadvantage of such a cooler is the low efficiency of the cooling process due to the inability to use forced (with the help of a pump) circulation of overboard water, as well as the bulkiness of the structure, which is determined by the significant dimensions of the exhaust pipe that provides “heat traction”.

The closest analogue of the claimed technical solution is the ship's outboard cooler (copyright certificate No. 901168, publ. 01/30/1982, author A.D. Chumachenko). The marine outboard cooler includes a heat exchanger block body with a stack of heat exchanger pipes fixed in the tube boards and pipes for supplying and discharging the cooled medium into the annulus, as well as two covers adjacent to the pipe boards, one of which is equipped with pipes for the input and output of the sea water. The cooler provides for the possibility of forcing, for example, using a pump, pumping sea water through a heat exchange unit with its subsequent discharge overboard.

The disadvantages of the known technical solution include the lack of efficiency of the outboard equipment, due to the fact that the cooler does not provide for the utilization of "waste" heat removed from the cooled medium, the seawater heated in the cooler is discharged overboard without disposal. This reduces the effectiveness of outboard equipment according to the efficiency criterion. Also, the cooler is a source of increased vibration and noise arising from the forced pumping of sea water through the pipe cavity. In addition, during the operation of the cooler, a “thermal trace” is formed from the warm water discharged overboard, which impairs the secrecy of the object (GVA).

These shortcomings limit the possibility of using an outboard cooler in promising HVA, where high demands are placed on the efficiency of outboard equipment, including in terms of vibro-acoustic characteristics.

The objective of the proposed group of inventions is the creation of a highly efficient method for cooling the environment in outboard equipment and marine outboard cooler for its implementation.

The technical result of the proposed solution is to increase the efficiency of outboard equipment by expanding its functionality, using outboard pressure as an energy source, utilizing waste heat and neutralizing the “thermal trail” left by the outboard cooler, and damping vibration.

The specified technical result is achieved by the fact that in the method of cooling the medium in the outboard equipment, including supplying the cooled medium to the annular space of the heat exchange unit and forcing the cooling medium (sea water) through the pipes of the heat exchange unit, the outboard water leaving the pipes is sent to the desalination unit inlet, which it is subjected to desalination on membrane desalination elements, then the brine is dumped overboard, and desalinated water is used for its intended purpose. In this case, cooling is carried out predominantly at sea pressure not less than the osmotic pressure of sea water.

The specified technical result is also achieved by the fact that the ship's outboard cooler is made in the form of a multifunctional module. The module contains a heat exchange unit with a package of heat exchange pipes fixed in the tube sheets, pipes for supplying and discharging the cooled medium into the annulus, as well as two covers adjacent to the tube plates. One of the covers is equipped with inlet and outlet water outlets. Also, a desalination unit is placed in the multifunctional module coaxially to the heat-exchange unit so that its body is docked with its ends to the covers. At least one membrane desalination element with a central collector, which is connected to a fitting for draining desalinated water, is installed in the cavity of the casing of the desalination unit. Outboard outlet pipe is connected to the casing cavity of the desalination unit. Through-holes are made in a section of the casing of the desalination unit within the lid cavity that does not have nozzles. In this case, the through holes are made with the condition that the total passage section of the holes is not less than the passage section of the overboard water inlet pipe.

Since the cooler is outboard, it operates under external hydrostatic pressure P _zab , depending on the immersion depth of the HVA. The flow of cooling medium emerging from the pipes is also under pressure P _zab . If this flow is directed to the inlet of a reverse osmosis desalination module equipped with a semipermeable membrane, while the working pressure is not less than the osmotic pressure of sea water, the process of desalination according to the reverse osmosis principle will begin. Seawater in the desalination module is divided into two streams: desalinated water (permeate) and brine. Desalinated water is discharged through the seawater into the GVA and used for its intended purpose, for example, for drinking. The brine is thrown overboard. At the same time, a special high-pressure pump is not required, the process is only due to overboard pressure.

The invention is illustrated by drawings, where:

- in FIG. 1 shows a sectional shipboard cooler,

- in FIG. Figure 2 shows the layout of the ship's outboard cooler overboard the GVA.

The marine outboard cooler is made in the form of a multifunctional module consisting of hydraulically and technologically interconnected heat exchange unit 1 and desalination unit 2.

The heat exchange unit 1 contains (Fig. 1) a package of heat exchange tubes 3 fixed in tube plates 4 and 5, a pipe 6 for supplying a cooled medium to the annulus and a pipe 7 for discharging a cooled medium. To ensure strength when working at great depths, the housing of the heat exchange unit 1 is made thick-walled. For intensification of heat transfer in block 1, transverse partitions are provided 8. Two covers 9 and 10 adjacent to pipe boards 4 and 5 can be removable or made integrally with block 1. Cover 9 is equipped with nozzles: 11 for entry and 12 for to exit sea water. The pipe 12 simultaneously serves to exit the brine. The cover 10 is made without nozzles. Since the covers are almost unloaded during operation of the cooler (the pressure inside the covers is the same as outside, overboard), the covers can be made lightweight.

In the heat exchange unit 1, a desalination unit 2 is coaxially placed, including a cylindrical body 13, which is docked with thick-walled plugs 14 and 15 to the covers 9 and 10. In the cavity of the body 13, at least one membrane desalination element (MOE) 16 is installed, which is a package of semi-permeable membranes 17 wound in a roll around a central collector 18. The MOE 16 is installed so that its end edge is spaced from the plug 15 at a distance H, which provides an end-to-side entry of sea water into the membrane package. When using several MOEs, they can be connected in series with each other using collectors, while increasing the yield of desalinated water. The collector 18 is used to collect desalinated water, it is connected to the fitting 19, located on the plug 14 of the housing 13 of the desalination unit 2. The pipe 12 for the outlet of sea water (brine) communicates with the cavity of the housing 13. In the walls of the housing 13 located in the cavity of the lid 10 in within the distance H, through holes 20 are made. These holes are intended for supplying outboard (sea) water to the MOE 16. The holes 20 are made in such a way that the area of their total passage section is not less than the area of the passage section of the inlet pipe 11 bortnoy water. The indicated bore orifice and their location on section H provide a balanced entry of overboard water into the cavity of the MOE 16 without throttling the flow and maintaining the necessary pressure to overcome the hydraulic resistance of the MOE. This allows the use of overboard pressure as the main source of energy for the desalination process according to the reverse osmosis principle. In addition, at the same time, the utilization of waste heat removed along with the seawater from the cavity of the heat exchange unit is ensured.

The marine outboard cooler is located overboard of the sturdy hull of the GVA 21 (Fig. 2). The hydraulic connection of the cooler with the GVA 21 is carried out through special (outboard) pipelines: through the nozzles 6 and 7 for supplying and discharging the cooled medium, as well as through the nipple 19 for draining desalinated water into the GVA 21. For the operation of the heat exchange unit, two forced flows are necessary: the flow of the cooling overboard water inside the heat exchange tubes and the flow of the cooled medium in the annulus. Both flows are provided by external GVA pumps that are not part of the outboard cooler.

For operation of the desalination unit, the flow of outboard (salt) water above the surface of the semipermeable membrane under a working pressure of at least osmotic, for example, 2.8 MPa (28 kgf / cm ² ) for standard ocean water with a salinity of 35 g / l, is required. This working pressure is provided by outboard hydrostatic pressure, for example, at a GVA immersion depth of 280 m and deeper. At a pressure of less than 2.8 MPa (28 kgf / cm ² ), the reverse osmosis process slows down or may stop altogether. For pumping overboard water through a desalination unit, some pressure is also required to overcome the longitudinal (between the layers of the MOE) membrane resistance. However, this pressure is negligible compared to the working pressure of the reverse osmosis process, which provides for pushing overboard water through the membrane (transverse flow). Thus, the same pump, for example, a centrifugal pump, can be used to pump overboard water through a desalination unit and through a heat exchange unit.

The method of cooling the environment in outboard equipment using the inventive ship's outboard cooler in it is as follows (Fig. 1 and 2).

An outboard centrifugal pump 22 is included, located near the ship's outboard cooler. Cold sea water through the nozzle 11 enters the cooler cavity under pressure, passes inside the heat exchange tubes 3, is heated by taking heat from the hot medium in the annulus and enters the lid cavity 10, and from it through the openings 20 into the cavity of the desalination unit body 13 2. The direction of water flows in FIG. 1 is shown by thin arrows. Special cuffs (they are not shown in Fig. 1) ensure the flow of overboard water through the MOE 16 in only one direction, as shown by the large arrow on the side surface of the MOE 16. Since the cooler is located overboard, the overboard water under a hydrostatic pressure of 28 kgf / cm ² or more (depending on the immersion depth of the GVA) is supplied to the desalination unit 2 and desalinated on semipermeable membranes 17 inside the MOE 16 according to the principle of reverse osmosis with the formation of desalination products: brine and desalinated water. At the same time, with an increase in the temperature of sea water heated in the pipes of the heat exchange unit 1, the efficiency of the desalination process increases: it has been theoretically and experimentally proved that with an increase in the temperature of sea water by 1 ° C, the yield of desalinated water increases by 3%.

Simultaneously with the movement of overboard water through the MOE 16, the pulsation of the water flow from the external pump 22 is suppressed, the cooler vibration is reduced and the noise is reduced due to the noise-suppressing properties of the MOE 16 and the elastic characteristics of the semipermeable membranes 17. Figuratively speaking, the MOE 16 works as a kind of damper. The brine pressure of the pump 22 is thrown overboard through the pipe 12, and desalinated water through the nozzle 19 is discharged from the cooler through a special outboard pipe into the cavity of the GVA 21, where it is discharged into a container under atmospheric pressure and then used by the crew for domestic needs, for example, for drinking. At the same time, outboard pressure acts on the semipermeable membrane 17 from the outside (in the cooler), and is almost atmospheric from the inside (in the cavity of the manifold 18 connected to the GVA 21), which ensures the pressure drop across the membrane, which is necessary for the reverse osmosis process.

Cooled hot medium (for example, fresh water, condensate, oil, etc.) from the GVA 21 cavity under pressure is supplied to the cooler through the pipe 6, passes in the annulus between the transverse partitions 8, is cooled and already cooled through the pipe 7 is returned to the GVA 21. In this case, the transfer of heat from the hot medium to the cold is carried out simultaneously through the outer surfaces of the heat exchange tubes 3 and the outer surface of the casing 13 of the desalination unit 2, which is in direct contact with the cooled medium. Thus, the desalination unit 2, as an integral part of the multifunctional unit, also participates in the processes of cooling the environment and utilizing waste heat.

The desalinated water on-board cooler performance depends on the depth of immersion of the GVA (and, accordingly, on the magnitude of the working pressure), the salinity of the sea water and its temperature. Based on these parameters, the corresponding type of MOE and their number should be selected. In the autonomous navigation mode of the GVA, maintenance of the ship's outboard cooler, including the heat exchange unit and desalination unit, is not required, the necessary routine operations are carried out only while it is in the base.

When using a marine outboard cooler, an increase in the efficiency of the outboard equipment of the GVA is achieved. The specified technical result is achieved due to the fact that:

- the ship's overboard cooler is made in the form of a multifunctional module, in which a desalination unit is placed coaxially to the body of the heat exchange unit, and therefore two processes are simultaneously implemented: cooling the environment and desalination of sea water;

- the desalination unit is docked with its ends to the covers, which makes it possible to use the same outboard water flow for cooling and desalination purposes, and also ensures the optimal layout of the multifunctional unit;

- the proposed location of the inlet and outlet pipes of the sea water directs the flow of sea water in the ship's sea cooler guaranteed through one or more MOE, while also improving the vibro-acoustic characteristics of the sea-side equipment due to the noise and vibration-suppressing properties of the membrane desalination elements;

- in the cavity of the casing of the desalination unit, it is possible to place one or more MOEs connected to the fitting for the removal of desalinated water. When using several MOEs connected in series, the desalinated water productivity can be increased to the required value;

- placement of through holes is provided on a section of the desalination unit casing within the lid cavity that does not have nozzles, which ensures utilization of waste heat: the seawater heated in the heat exchange unit is immediately sent to the MOE for desalination;

- provides for the utilization of waste heat from the heat exchange unit and the use of outboard pressure as the working pressure of the desalination process, which provides a significant reduction in energy and labor costs when working outboard equipment;

- masking of the trace of GVA due to brine coming out of the desalination module is provided. Since brine of increased density and elevated temperature is thrown overboard, the outboard cooler (and the GVA itself, respectively) leave behind a “trace” that can be detected. It is known that heated water has a lower density than cold and therefore rises to the surface and becomes distinguishable by means of detection, for example, using infrared (IR) detectors mounted on aircraft. GWA's secrecy may thus be compromised. In the proposed method, the warm brine will not be able to rise to the surface, since it is more salty than sea water and has a density higher than sea water. Consequently, the brine, at least, will spread horizontally under water, or even fall below if its salinity is significant. In this case, the detection of a “trace” from the cooler and from the GVA in the surface layers of seawater using infrared detectors will be impossible.

The proposed technical solution can be used in promising projects of the GVA.

Claims (3)

1. The method of cooling the medium in the outboard equipment, including the supply of the cooled medium into the annular space of the heat exchange unit and the forced supply of overboard water through the pipes of the heat exchange unit, characterized in that the cooling is carried out with an outboard pressure of at least osmotic pressure of sea water leaving the heat exchange tubes sent to the input of the desalination unit, in which it is subjected to desalination on membrane desalination elements, then the brine is dumped overboard, and the desalinated water is used Use. 2. A marine outboard cooler comprising a heat exchange unit with a stack of heat exchanger tubes fixed in the tube sheets, and pipes for supplying and discharging the cooled medium into the annulus, as well as two covers adjacent to the pipe boards, one of which is equipped with pipes for the input and output of the sea water, characterized in that it is made in the form of a multifunctional module, in which a desalination unit is placed coaxially to the heat exchange unit, the casing of which is docked with its ends to the covers, in the cavity of the casing the desalination unit at least one membrane desalination element is installed with a central collector connected to a fitting for discharging desalinated water, while the outlet pipe of the seawater is connected to the cavity of the desalination block body, and on the section of the desalination block case within the cover cavity that does not have nozzles, through holes. 3. Shipboard outboard cooler according to claim 2, characterized in that the through holes are made with the condition that the total passage section of the holes is not less than the passage section of the overboard water inlet pipe.

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