Multi stage evaporator

Abstract

A multi-stage evaporator according to one aspect of the present invention may include a tank communicating with an inlet pipe, a plurality of trays spaced apart from each other in multiple stages and disposed inside the tank, a working fluid flowing out from the inlet pipe and contained in the trays, and a plurality of heat transfer tubes disposed inside the trays and submerged in the working fluid.

Description

Technology Field

[0001] The present invention relates to a multi-stage evaporator, and more specifically, to a multi-stage evaporator capable of efficiently evaporating a working fluid using a small amount of working fluid. Background Technology

[0002] The evaporator is a key component in turbo chillers, adsorption, and absorption heat pump systems that generates cold energy by evaporating the working fluid; improving the heat transfer performance of the evaporator can increase the overall system efficiency.

[0003] In conventional flooded-type evaporators, the heat transfer tubes where heat transfer occurs are completely submerged in the working fluid; as heat transfer is carried out by natural convection, which has a low heat transfer coefficient, the evaporator's performance deteriorates.

[0004] In addition, there is a disadvantage in that a large amount of working fluid must be filled to completely immerse the fin tube in the working fluid. The problem to be solved

[0005] The present invention provides a multi-stage evaporator capable of efficiently evaporating a working fluid using a small amount of working fluid. means of solving the problem

[0006] A multi-stage evaporator according to one aspect of the present invention may include a tank communicating with an inlet pipe, a plurality of trays spaced apart from each other in multiple stages and disposed inside the tank, a working fluid flowing out from the inlet pipe and contained in the trays, and a plurality of heat transfer tubes disposed inside the trays and submerged in the working fluid.

[0007] A multistage evaporator according to one aspect of the present invention may further include a plurality of heat transfer fins disposed inside the tray and penetrating the heat transfer tube to be submerged in the working fluid.

[0008] According to one aspect of the present invention, the trays may be arranged in a zigzag pattern along a vertical direction parallel to each other.

[0009] According to one aspect of the present invention, the working fluid may flow out from the inlet pipe and be contained in the tray positioned at the top, and may flow sequentially overflowing from the tray positioned at the top to the tray positioned at the bottom.

[0010] According to one aspect of the present invention, one side of the tray may have a lower height than the other side.

[0011] According to one aspect of the present invention, a blocking plate may be formed extending upward on the upper part of the remaining side.

[0012] According to one aspect of the present invention, the working fluid may be contained in the tray such that a part of the heat transfer tube or a part of the heat transfer fin is submerged.

[0013] A multistage evaporator according to one aspect of the present invention may further include an absorption portion disposed on the outer surface of the heat transfer tube or on the side of the heat transfer fin.

[0014] According to one aspect of the present invention, the absorbent portion may be composed of at least one of a porous coating layer, a mesh screen, and microgrooves.

[0015] According to one aspect of the present invention, the microgrooves are formed on the side of the heat transfer fin along the vertical direction, and may be composed of a plurality of them and spaced apart from each other along the horizontal direction.

[0016] According to one aspect of the present invention, the microgrooves are formed on the outer surface of the heat transfer tube along the circumference of the heat transfer tube, and are composed of a plurality of grooves that are spaced apart from each other along the longitudinal direction of the heat transfer tube.

[0017] A multistage evaporator according to one aspect of the present invention may further include a recovery line installed between the lower part of the tank and the inlet pipe, and a pump installed in the recovery line to pump the working fluid collected at the lower part of the tank.

[0018] A multistage evaporator according to one aspect of the present invention may further include a plurality of baffles installed on the inner surface of the tank, spaced apart from each other along the vertical direction.

[0019] According to one aspect of the present invention, the side of the baffle and the side of the tray may be arranged along a diagonal direction by being inclined at a certain angle parallel to each other.

[0020] In a multistage evaporator according to one aspect of the present invention, the lower end of the baffle and the blocking plate are arranged facing each other, but spaced apart from each other to form a flow path. Effects of the invention

[0021] As described above, according to one aspect of the present invention, the working fluid is submerged only in a part of the heat transfer tube and a part of the heat transfer fin, and the absorbent part draws up the working fluid by capillary action so that a thin liquid film can be formed up to the remaining parts of the heat transfer tube and heat transfer fin.

[0022] Therefore, the amount of working fluid used can be minimized, and the evaporation heat transfer coefficient can be significantly improved. Brief explanation of the drawing

[0023] FIG. 1 is a schematic diagram of a multi-stage evaporator according to a first embodiment of the present invention. Figure 2 is an enlarged view of the tray shown in Figure 1. Figure 3 is a plan view of the tray shown in Figure 1. FIG. 4 is a first embodiment of an absorbent portion disposed on a heat transfer fin shown in FIG. 2. FIG. 5 is an enlarged view of part A shown in FIG. 2, which is a first embodiment of an absorption portion disposed in a heat transfer tube. FIG. 6 is a second embodiment of an absorbent portion disposed on a heat transfer fin shown in FIG. 2. FIG. 7 is an enlarged view of part A shown in FIG. 2, which is a second embodiment of an absorption section disposed in a heat transfer tube. FIG. 8 is a third embodiment of an absorbent portion disposed on a heat transfer fin shown in FIG. 2. FIG. 9 is an enlarged view of part A shown in FIG. 2, which is a third embodiment of an absorption portion disposed in a heat transfer tube. FIG. 10 is a schematic diagram of a multistage evaporator according to a second embodiment of the present invention. Figure 11 is an enlarged view of part B shown in Figure 10. Figure 12 is an enlarged view of part C shown in Figure 11. Specific details for implementing the invention

[0024] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are to be illustrated and described in detail. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0025] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this invention, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that in the accompanying drawings, identical components are indicated by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that may obscure the essence of the present invention will be omitted. For the same reason, some components in the accompanying drawings may be exaggerated, omitted, or schematically depicted.

[0027] Hereinafter, a multi-stage evaporator according to the first embodiment of the present invention will be described.

[0028] FIG. 1 is a schematic diagram of a multi-stage evaporator according to a first embodiment of the present invention, FIG. 2 is an enlarged view of the tray shown in FIG. 1, and FIG. 3 is a plan view of the tray shown in FIG. 1.

[0029] Referring to FIGS. 1 to 3, a multistage evaporator (100) may include a tank (110), a tray (120), a working fluid (130), a heat transfer tube (140), a heat transfer fin (150), and an absorption section (160).

[0030] The tank (110) is in the form of a polyhedron such as a hollow cylinder or a cube, and the upper part of the tank (110) can be connected to an inlet pipe (111) and an outlet pipe (112).

[0031] The tray (120) is a cuboid with an empty interior and an open top surface, and is positioned inside the tank (110) spaced apart from the inner surface of the tank (110), and can be fixed to the inner surface of the tank (110) via a known fixing member such as a bracket.

[0032] The tray (120) is made up of multiple trays and is spaced apart from one another in multiple stages and placed inside the tank (110), and can be arranged in a zigzag pattern parallel to one another along the vertical direction.

[0033] That is, the trays (120) facing each other in the vertical direction can be arranged sequentially by repeatedly moving in and out in the left and right directions from the top tray (120) to the bottom tray (120) with a portion misaligned.

[0034] The liquid working fluid (130) can be discharged from the inlet pipe (111) and contained in the tray (120).

[0035] More specifically, the working fluid (130) flows out from the inlet pipe (111) and falls into the uppermost tray (120-1) by its own weight, and can flow sequentially from the uppermost tray (120-1) to the lowermost tray (120-n) by overflowing.

[0036] For the working fluid (130) to flow out of the tray (120), one side (121) of the tray (120) is formed to be lower in height than the other side (122), and a blocking plate (123) may be formed extending upward on the top of the other side (see FIG. 2).

[0037] That is, the working fluid (130) can be induced to overflow to one side (121) of the tray (120) by the blocking plate (123).

[0038] The working fluid (130) overflowing from the tray (120-n) placed at the bottom can be collected and pooled at the bottom of the tank (110).

[0039] The heat transfer tubes (140) are made up of multiple tubes and placed inside the tray (120) and submerged in the working fluid (130), and can be spaced apart from each other parallel along the horizontal direction.

[0040] A refrigerant flows inside the heat transfer tube (140), and the working fluid (130) comes into contact with the outer surface of the heat transfer tube (140) to exchange heat with the refrigerant, causing it to evaporate and generate cold heat, and the working fluid (130) in the gaseous state can flow to the upper part of the tank (110) and enter the outlet tube (112).

[0041] The heat transfer fin (150) is in the form of a plate, and the heat source of the refrigerant is transferred to the heat transfer fin (150) so that the working fluid (130) in contact with the heat transfer fin (150) can evaporate, and the surface area of ​​the heat transfer fin (150) in contact with the working fluid (130) is relatively larger than that of the heat transfer tube (140), so that the evaporation performance can be improved.

[0042] The heat transfer fins (150) are made up of multiple fins and can be placed inside the tray (120) and submerged in the working fluid (130).

[0043] The heat transfer fins (150) are spaced apart from each other along the length direction of the heat transfer tube (140) and can be sequentially penetrated into the heat transfer tube (140) and fixed by welding (see FIG. 3).

[0044] The heat transfer tube (140) and heat transfer fin (150) are also placed at the bottom of the tank (110) and can be submerged in the working fluid (130) accumulated at the bottom of the tank (110).

[0045] The working fluid (130) is contained in a tray (120) so that a part of the heat transfer tube (140) or a part of the heat transfer fin (150) is submerged, and the absorbent part (160) may be placed on the outer surface of the heat transfer tube (140) or on the side of the heat transfer fin (150) (see FIG. 2).

[0046] That is, the absorption section (160) draws up the working fluid (130) by capillary action so that a thin liquid film can be formed up to the remaining parts of the heat transfer tube (140) and heat transfer fin (150).

[0047] Therefore, the amount of working fluid (130) used can be minimized, and the evaporation heat transfer coefficient can be greatly improved.

[0048] FIG. 4 is a first embodiment of an absorbent portion disposed on a heat transfer fin as shown in FIG. 2, and FIG. 5 is a first embodiment of an absorbent portion disposed on a heat transfer tube as shown in FIG. 2 AA section view.

[0049] Referring to FIGS. 4 and 5, the absorbent portion (160) is made of a porous coating layer (161) and may be placed on the side of the heat transfer fin (150) or placed along the circumference of the heat transfer tube (140) on the outer surface of the heat transfer tube (140).

[0050] The porous coating layer (161) is made of metal foam, and the metal foam refers to a foamed metal having uniform nano-sized pores formed therein, and can be fixed to the side of the heat transfer fin (150) or the outer surface of the heat transfer tube (140) by welding or rolling.

[0051] FIG. 6 is a second embodiment of an absorbent portion disposed on a heat transfer fin as shown in FIG. 2, and FIG. 7 is a second embodiment of an absorbent portion disposed on a heat transfer tube as shown in FIG. 2, AA section view.

[0052] Referring to FIGS. 6 and 7, the absorbent portion (160) is made of a mesh screen (162) and may be placed on the side of the heat transfer fin (150) or placed along the circumference of the heat transfer tube (140) on the outer surface of the heat transfer tube (140).

[0053] The mesh screen (162) is made of fabric or ceramic and can be fixed to the side of the heat transfer fin (150) or the outer surface of the heat transfer tube (140) by an adhesive method.

[0054] FIG. 8 is a third embodiment of an absorbent portion disposed on a heat transfer fin as shown in FIG. 2, and FIG. 9 is a third embodiment of an absorbent portion disposed on a heat transfer tube as shown in FIG. 2 AA section view.

[0055] Referring to FIGS. 8 and 9, the absorption portion (160) is formed by a microgroove (163) and is formed on the side of the heat transfer fin (150) along the vertical direction, and can be formed in multiple numbers and spaced apart from each other along the length direction of the heat transfer fin (150).

[0056] Alternatively, the microgrooves (163) may be formed on the outer surface of the heat transfer tube (140) along the circumference of the heat transfer tube (140), and may be made up of multiple grooves spaced apart from each other along the length direction of the heat transfer tube (140).

[0057] Hereinafter, a multi-stage evaporator according to the second embodiment of the present invention will be described.

[0058] FIG. 10 is a schematic diagram of a multistage evaporator according to a second embodiment of the present invention, FIG. 11 is an enlarged view of part B shown in FIG. 10, and FIG. 12 is an enlarged view of part C shown in FIG. 11.

[0059] Referring to FIGS. 10 to 12, the multistage evaporator (100') may further include a recovery line (171), a pump (170), and a baffle (180).

[0060] A recovery line (171) is installed between the bottom of the tank (110) and the inlet pipe (111), and a pump (170) is installed in the recovery line (171) to pump the working fluid (130) accumulated in the bottom of the tank (110) to the inlet pipe (111), and the working fluid (130) pumped to the inlet pipe (111) can be placed back into the tray (120) and reused.

[0061] Since the working fluid (130) may not be sufficiently separated into gas and liquid phases when heat-exchanging with the refrigerant and may flow into the outlet pipe (112) together with the gas phase and liquid phase, a baffle (180) may be installed on the inner side of the tank (110) to prevent this.

[0062] The baffles (180) are made up of multiple pieces and spaced apart from each other along the vertical direction, and the upper ends of the baffles (180) can be fixed to the inner surface of the tank (110) by means of known fixing members, such as bolts, or by welding.

[0063] The side of the tray (120) is positioned at a certain angle (θ) along the diagonal direction to guide the working fluid (130) in the gas phase to flow toward the baffle (180).

[0064] The baffle (180) is positioned along a diagonal direction at a certain angle so as to be positioned parallel to the side of the tray (120), and the bottom of the baffle (180) is positioned opposite (d2) the blocking plate (123), so that a flow path (d1) can be formed by being spaced apart from each other (see FIG. 11).

[0065] That is, as the gaseous working fluid (130) collides with the baffle (180) and changes its flow direction while passing through the flow path, the liquid working fluid (130) accompanying the gaseous working fluid (130) is separated and flows along the side of the baffle (180) by its own weight and can fall onto the tray (120).

[0066] A plurality of through holes (181) are formed in the baffle (180) at spaced intervals from each other, and the through holes (181) are formed in a zigzag pattern so that the working fluid (130) passes through the through holes (181) while changing its flow direction, thereby allowing for smoother separation of the working fluid (130) gas and liquid (see FIG. 12).

[0067] Although an embodiment of the present invention has been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention. Explanation of the symbols

[0068] 100,100': Multistage evaporator 110: Tank 111: Inlet pipe 112: Outlet pipe 120: Tray 120-1: Top tray 120-n: Bottom tray 121: One side of the tray 122: Remaining side of the tray 123: Block plate 130: Working fluid 140: Heat transfer tube 150: Heat transfer fins 160: Absorber 161: Porous coating layer 162: Mesh screen 163: Microgrooves 170: Pump 171: Retrieval Line 180: Baffle 181: Communion

Claims

Claim 1 A multi-stage evaporator comprising: a tank communicating with an inlet pipe; a plurality of trays arranged inside the tank, spaced apart from one another in multiple stages; a working fluid flowing out from the inlet pipe and contained in the trays; a plurality of heat transfer tubes arranged inside the trays and submerged in the working fluid; a plurality of heat transfer fins in a plate shape arranged inside the trays and submerged in the working fluid; an absorption portion arranged on the outer surface of the heat transfer tubes and on the sides of the heat transfer fins; and a plurality of baffles installed on the inner surface of the tank, spaced apart from one another along a vertical direction; wherein the heat transfer tubes are arranged spaced apart from one another parallel along a horizontal direction, and the heat transfer fins are arranged spaced apart from one another along the length direction of the heat transfer tubes, sequentially penetrating the heat transfer tubes and fixed to the heat transfer tubes, and the working fluid is contained in the trays such that a portion of the heat transfer tubes and a portion of the heat transfer fins are submerged, and through holes are formed in the baffles in a zigzag pattern along the thickness direction of the baffles. Claim 2 delete Claim 3 A multi-stage evaporator according to claim 1, characterized in that the trays are arranged in a zigzag pattern along a vertical direction parallel to each other. Claim 4 A multi-stage evaporator according to claim 1, characterized in that the working fluid flows out of the inlet pipe and is contained in the tray positioned at the top, and flows sequentially overflowing from the tray positioned at the top to the tray positioned at the bottom. Claim 5 A multi-stage evaporator according to claim 1, characterized in that one of the sides of the tray has a lower height than the other side. Claim 6 A multi-stage evaporator characterized in that, in claim 5, a blocking plate is formed extending upwardly at the top of the remaining side. Claim 7 delete Claim 8 delete Claim 9 A multistage evaporator according to claim 1, wherein the absorption portion is composed of at least one of a porous coating layer, a mesh screen, and microgrooves. Claim 10 A multi-stage evaporator according to claim 9, wherein the microgrooves are formed on the side of the heat transfer fin along the vertical direction, and are composed of a plurality of grooves spaced apart from each other along the horizontal direction. Claim 11 A multi-stage evaporator according to claim 9, wherein the microgrooves are formed on the outer surface of the heat transfer tube along the circumference of the heat transfer tube, and are composed of a plurality of grooves spaced apart from each other along the length direction of the heat transfer tube. Claim 12 A multi-stage evaporator according to claim 1, further comprising: a recovery line installed between the lower part of the tank and the inlet pipe; and a pump installed in the recovery line to pump the working fluid collected in the lower part of the tank. Claim 13 delete Claim 14 A multi-stage evaporator according to claim 1, characterized in that the baffle and the side of the tray are arranged along a diagonal direction, inclined at a certain angle to each other in a mutually parallel manner. Claim 15 A multi-stage evaporator characterized in that, in claim 6, the lower end of the baffle and the blocking plate are arranged facing each other and spaced apart from each other to form a flow path.

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