CN113716011B - Auxiliary cooling system for pump for ship - Google Patents

Abstract

The invention belongs to the field of heat pipe cooling systems, and specifically discloses a pump auxiliary cooling system for ships, which comprises an evaporator, a condenser and a rotary pump, wherein: a steam collecting chamber of the evaporator is connected to the condenser through a steam pipe, The liquid collecting chamber of the evaporator is connected to the condenser through a condensation reflux pipeline, and the installation position of the condenser is higher than the evaporator; a liquid storage device and an ejector are arranged on the condensation reflux pipeline, and the liquid storage device It communicates with the ejector through the rotary pump and forms an auxiliary circuit together. The invention can realize the active temperature control of the system by changing the input voltage of the gear pump to adjust the flow rate of the refrigeration working medium, solve the problem that the temperature cannot be controlled by the traditional separate heat pipe, and at the same time improve the mass flow rate of the fluid in the main circuit of the cooling system, so as to ensure the startup of the system during the operation of the ship. and operation stability, and achieve the goal of reducing energy consumption.

Description

A pump auxiliary cooling system for ships

technical field

The invention belongs to the field of heat pipe cooling systems, and more specifically relates to a pump auxiliary cooling system for ships.

Background technique

The traditional air cooling devices used on ships are generally water chillers, which cool the air through cold water flowing through finned tubes, which requires additional high-power water pumps and fans to obtain better heat dissipation effects, so energy consumption is large, and ships decreased self-sustainability.

In recent years, heat pipe technology has been used in various fields such as cooling of high heat flux electronic devices and thermal control of spacecraft due to its good heat transfer performance and reliability. As a passive heat exchange system evolved from a heat pipe heat exchanger, the separated heat pipe can theoretically be realized by placing the condenser outside the ship because of its flexible layout and the ability to realize long-distance heat transport. Heat exchange between inboard and outboard seawater. However, the heat transfer performance of the traditional heat pipe evaporator is poor. At the same time, the separated heat pipe system also relies on the heat exchange between the condenser and seawater. The insufficient heat dissipation of the condenser will not meet the cooling capacity of the ship when the ship is running at low speed or standing still. requirements, and may even lead to start-up failure of the split heat pipe. At the same time, the inability to adjust the temperature is also one of the disadvantages of the traditional separated heat pipe, so it is difficult to apply it to the air-conditioning system of the ship.

In addition, the traditional heat pipe evaporator is generally a shell-and-tube structure, using a smooth round tube with fins. Although it is simple to process, because the smooth surface has fewer vaporization cores, the evaporation process is not easy to nucleate, so the heat transfer performance is not ideal. It is difficult to meet the cooling capacity requirements during the operation of the ship for the separated heat pipe.

Contents of the invention

Aiming at the above defects or improvement needs of the prior art, the present invention provides a pump auxiliary cooling system for ships. Its purpose is to solve the problem that the traditional separated heat pipe cannot regulate the temperature, and at the same time improve the mass flow rate of the main circuit fluid of the cooling system to ensure The stability of system start-up and operation during ship operation.

In order to achieve the above object, the present invention proposes a pump auxiliary cooling system for ships, including an evaporator, a condenser and a rotary pump, wherein:

The steam collection chamber of the evaporator is connected to the condenser through a steam pipe, the liquid collection chamber of the evaporator is connected to the condenser through a condensation return pipe, and the installation position of the condenser is higher than that of the evaporator; the condensation return A liquid reservoir and an ejector are arranged on the pipeline, and the liquid reservoir and the ejector communicate through the rotary pump and together form an auxiliary circuit.

As a further preference, the evaporator includes a steam collecting cavity, a liquid collecting cavity, a heat exchange tube and a baffle grid, wherein: the steam collecting cavity, the heat exchange tube, and the liquid collecting cavity are connected in sequence, and the baffle grid Used to fix the heat exchange tube.

As a further preference, the inner wall of the heat exchange tube is provided with a plurality of dovetail grooves along the circumference.

As a further preference, the width of each dovetail-shaped groove is 0.2 mm˜1 mm, and the distance between two adjacent dovetail-shaped grooves is not less than 0.5 mm.

As a further preference, the bottom of the dovetail groove is provided with a plurality of serrations.

As a further preference, the width of each sawtooth is 30 μm˜80 μm.

As a further preference, the baffle grid includes a fixing part and a plurality of wave-shaped deflecting rods installed in the fixing part, the multiple wave-shaped deflecting rods are arranged in parallel, and the positions of the waves of the adjacent wave-shaped deflecting rods are misaligned ; The heat exchange tubes are installed in the wave-shaped gap between the corrugated baffle rods, so as to realize the triangular layout of the heat exchange tubes.

As a further preference, the wave-shaped baffle rod is oval.

As a further preference, the rotary pump is a gear pump.

As a further preference, side valves are installed on the condensate return pipe and the steam pipe, and the side valve is close to the side of the condenser.

Generally speaking, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

1. The pump-assisted cooling system proposed by the present invention is equipped with a rotary pump in the auxiliary circuit, and the active temperature control of the system can be realized by changing the input voltage of the rotary pump to adjust the circulation volume of the refrigerant. Combined with the introduction of the ejector, the auxiliary The main loop injecting working medium in the loop can effectively increase the fluid mass flow rate of the main loop, thereby improving the operating performance of the system.

2. When the pump-assisted cooling system is running, the gravity potential difference between the condenser and the evaporator is the main circulation power. By adding a pump-driven circuit as the auxiliary driving force, the advantages of the active and passive cooling systems are combined, and the traditional refrigerant Compared with the water system, the energy consumption required for system operation is reduced; at the same time, it can also ensure the normal startup and stable operation of the separated heat pipe when the ship is sailing at low speed.

3. In the present invention, a dovetail-shaped micro-channel is provided inside the heat exchange tube, which is equivalent to a group of micro-heat pipe arrays, and a micron-level sawtooth structure is further modified in the channel, so that the micro-channel has higher heat exchange performance. Specifically, with the phase change of the refrigerant in the tube, while increasing the vaporization core on the inner surface of the tube, the axial capillary pressure difference can be generated by the sharp corner area or the fine channel, and then provide additional surface tension to assist gravity to maintain separation The circulation of the type heat pipe, and no moving parts, has the advantages of convenient processing and maintenance-free; at the same time, considering the structural strength and reliability of the pipe, the distance between the two channels should not be less than 0.5mm.

4. The traditional baffle rod heat exchanger uses round straight rods to support the heat exchange tubes. Limited by the requirements of heat transfer and compact structure, the distance between the heat exchange tubes is often small, which makes the space for the baffle rod layout relatively small. Therefore, the commonly used triangular pipe layout method is difficult to apply in the baffle rod heat exchanger. The invention uses adjacent corrugated rods to position the heat exchange tubes, and only one baffle grid is needed to support the heat exchange tubes; at the same time, the corrugated baffle rods can form turbulent flow when the fluid flows through, which is comparable to the straight rods. It has a better mixed flow temperature uniformity effect, that is, the temperature distribution of the cross section is more uniform, so that the evaporator has a more efficient heat exchange performance.

5. In the present invention, the concavo-convex positions of the adjacent corrugated baffle rods on the shell side of the evaporator are misplaced, so as to realize the triangular tube layout of the heat exchange tubes between the corrugated baffle rods, and the space utilization rate is higher compared with the square tube layout method; Furthermore, the number of shell-side pipes can be increased in the same space, thereby increasing the heat exchange area between the thermal fluid and the pipes. This structure solves the problem that the triangular tube layout method is difficult to apply in the baffle rod heat exchanger, and improves the compactness of the heat exchanger.

6. The cross section of the corrugated baffle rod is preferably elliptical. Compared with the commonly used circular cross-section rod, the elliptical cross-section rod has better fluid temperature field uniformity, stronger convective heat transfer performance, and better meets the needs of ships. Cooling capacity requirements during operation.

Description of drawings

Among Fig. 1 (a), (b) is the structural representation of heat pipe evaporator of the embodiment of the present invention;

Fig. 2 is a schematic diagram of the arrangement of steam pipelines and corrugated baffle rods according to the embodiment of the present invention;

(a) and (b) in Fig. 3 are schematic diagrams of dovetail-shaped grooves and sawtooth structures according to an embodiment of the present invention;

Fig. 4 is a schematic structural diagram of a corrugated baffle rod according to an embodiment of the present invention;

(a) and (b) in Fig. 5 are cross-sectional schematic diagrams of circular and elliptical corrugated baffle rods according to embodiments of the present invention;

Fig. 6 is a schematic structural diagram of a pump auxiliary cooling system for a ship according to an embodiment of the present invention.

In all the drawings, the same reference numerals are used to represent the same elements or structures, among which: 1-steam collection chamber, 2-liquid collection chamber, 3-heat exchange tube, 4-wave baffle rod, 5-lead Ejector, 6-condensate return pipe, 7-steam pipe, 8-side valve, 11-condenser, 12-evaporator, 13-reservoir, 14-rotary pump.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

A pump-assisted cooling system for a ship provided by an embodiment of the present invention, as shown in FIG. Pipeline 7 and side valve 8, wherein:

The steam collection chamber 1 of the evaporator 12 is connected to the condenser 11 through the steam pipe 7, and the liquid collection chamber 2 of the evaporator 12 is connected to the condenser 11 through the condensation return pipe 6, and the condenser 11 is installed outside the cabin at a high position. In the evaporator 12; the condensation return pipeline 6 is divided into a main circuit and an auxiliary circuit equipped with a rotary pump 14 from the liquid reservoir 13, and rejoins through the ejector 5, and the rotary pump 14 is preferably a gear pump; liquid storage The top of the device 13 is the filling port, and the two openings at the bottom are respectively connected to the main circuit and the auxiliary circuit. As an air inlet and outlet; the side valve 8 is arranged on the condensate return pipe 6 and the steam pipe 7 near the side of the condenser 11 .

Specifically, the evaporator 12 includes a steam collecting chamber 1, a liquid collecting chamber 2, a heat exchange tube 3 and a baffle grid, as shown in FIG. 1 , wherein:

The steam collection chamber 1, the heat exchange tube 3, and the liquid collection chamber 2 are connected in sequence, and the baffles can be multiple, and each baffle includes a ring-shaped fixing part and a plurality of corrugated wires installed in the fixing part. The baffle rods 4, the heat exchange tubes 3 are installed in the wave-shaped gaps between the corrugated baffle rods 4, as shown in FIG. 2 .

Further, as shown in Figure 4, a plurality of corrugated baffle rods 4 are arranged in parallel, and the positions of the corrugations of adjacent corrugated baffle rods 4 are misplaced, so as to realize the triangular arrangement of the heat exchange tubes 3, thus increasing the shell-side The number of tubes, the heat exchange area, and the area of the turbulence area improve the compactness of the heat exchanger. The corrugated baffle rod 4 is circular or elliptical, preferably elliptical. As shown in FIG. 5 , the elliptical cross-section rod has better fluid temperature field uniformity and stronger convective heat transfer performance.

Further, as shown in Figure 3, the inner wall of the heat exchange tube 3 is provided with a plurality of dovetail-shaped grooves along the circumference, and the bottom of the dovetail-shaped grooves is provided with a plurality of micron-scale sawtooth; specifically, for a diameter of 8mm The nickel-nickel-nickel copper B10 tube, the structural size of the dovetail-shaped channel is 0.3mm×0.3mm×0.5mm, and 20 dovetail-shaped channels are provided. The micron-scale sawtooth in the dovetail groove uses rectangular sawtooth with a size of 50 μm×50 μm. It should be pointed out that considering the structural strength and reliability of the pipeline, the distance between the two channels should not be less than 0.5mm, and the aspect ratio and number of channels can be adjusted according to the capillary limit and boiling limit. The capillary force of the channel is provided by the curvature difference of the gas-liquid two-phase interface along the direction of the pipeline. When the system is working, the refrigerant in the heat exchange tube undergoes a phase change, and the curvature of the meniscus in the channel on the upper side of the pipeline increases. The capillary force drives the refrigerant to continuously replenish the heat pipe.

In terms of processing, the evaporator adopts a tube-and-tube heat exchanger. In order to ensure that there is no leakage between the working fluid pipeline and the tube sheet, the connection is made by strength expansion and sealing welding to ensure that the connection is safe, reliable and leak-free. The working medium pipeline adopts argon arc welding all-welded structure, and has passed the strict leak test of helium mass spectrometry, and the leak rate test is 5*10 ^-9 Pa to ensure the sealing performance.

When the system is working, the equipment water that needs to be cooled enters the shell side of the evaporator 12 to exchange heat with the heat exchange tube 3. After being heated, the refrigerant in the heat tube changes into a gas phase and rises to the steam collecting chamber 1, and enters the condenser along the steam pipe 7 In 11, it is cooled by seawater. The condensed refrigerant flows into the liquid receiver 13 along the condensate return pipe 6 under the action of gravity. According to the operating conditions of the ship, turn off the rotary pump 14 when sailing at high speed, and the refrigerant returns to the liquid collection chamber 2 of the evaporator from the main circuit; turn on the rotary pump 14 when sailing at low speed, and adjust the flow rate of the working medium by adjusting the input power of the rotary pump 14. Adjustment, the working medium enters the main circuit and the auxiliary circuit respectively, and converges at the ejector 5, and finally returns to the liquid collection chamber 2 of the evaporator. The pump auxiliary cooling system for ships proposed by the present invention can solve the problem that the traditional separated heat pipes cannot regulate the temperature, and at the same time, it can enhance the stability of system start-up and operation when the ship is running, and achieve the goal of reducing energy consumption.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (7)

1. Pump-assisted cooling system for marine vessels, characterized by comprising an evaporator (12), a condenser (11) and a rotary pump (14), wherein:

the steam collection cavity (1) of the evaporator (12) is connected with the condenser (11) through a steam pipeline (7), the liquid collection cavity (2) of the evaporator (12) is connected with the condenser (11) through a condensation reflux pipeline (6), and the installation position of the condenser (11) is higher than that of the evaporator (12); a liquid storage device (13) and an ejector (5) are arranged on the condensation backflow pipeline (6), and the liquid storage device (13) and the ejector (5) are communicated through the rotary pump (14) and jointly form an auxiliary loop;

evaporimeter (12) are including album vapour chamber (1), album liquid chamber (2), heat exchange tube (3) and baffling bars, wherein: the steam collecting cavity (1), the heat exchange tube (3) and the liquid collecting cavity (2) are sequentially communicated, and the baffling grid is used for fixing the heat exchange tube (3); a plurality of dovetail-shaped grooves are formed in the inner wall of the heat exchange tube (3) along the circumferential direction;

the deflection grating comprises a fixing piece and a plurality of wave-shaped deflection rods (4) arranged in the fixing piece, the wave-shaped deflection rods (4) are arranged in parallel, and the wave concave-convex positions of the adjacent wave-shaped deflection rods (4) are arranged in a staggered manner; the heat exchange tubes (3) are arranged in the wavy gaps among the wavy baffle rods (4), so that triangular tube distribution of the heat exchange tubes (3) is realized.

2. The auxiliary cooling system for a marine pump according to claim 1, wherein each of the dovetail grooves has a width of 0.2mm to 1mm, and a distance between two adjacent dovetail grooves is not less than 0.5mm.

3. The marine pump auxiliary cooling system of claim 1, wherein the dovetail groove bottom is provided with a plurality of serrations.

4. The marine pump auxiliary cooling system of claim 3, wherein each of the serrations has a width of 30 to 80 μm.

5. Pump auxiliary cooling system for ships according to claim 1, characterised in that the wave-shaped baffle rod (4) is oval.

6. Pump auxiliary cooling system for ships according to claim 1, characterized in that the rotary pump (14) is a gear pump.

7. Marine pump auxiliary cooling system according to any one of claims 1-6, characterized in that a side valve (8) is mounted on each of the condensate return line (6) and the steam line (7), and the side valve (8) is located near the side of the condenser (11).

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