Phase change cold storage device with vortex coil

Abstract

The present invention provides a phase change cold storage device with a vortex coil, which belongs to the field of low temperature technology, and includes an inlet pipe, an outlet pipe, a tube sheet, a baffle, a vortex coil, a cylinder, a center pipe, a support frame, a head and a saddle. The tube sheet is fixedly connected to the cylinder, and holes are respectively opened at the lower end position and the center position of the tube sheet. The inlet pipe and the outlet pipe are respectively connected to the openings at the lower end position and the center position of the tube sheet. The baffle and the vortex coil are installed on the center pipe. One end of the center pipe is fixed on the tube sheet, and the other end is inserted on the support frame connected to the cylinder. The head is connected to the cylinder and is arranged on the other side opposite to the inlet pipe and the outlet pipe. The saddle is arranged below the cylinder. The present invention has a compact structure and is easy to manufacture. The vortex coil used is easy to enhance heat transfer. At the same time, it has a good cold storage effect and a wide range of applications.

Description

Technical Field

[0001] The present invention belongs to the field of cryogenic technology and can be applied to public buildings, air conditioning cold storage, refrigerated transportation, etc. More specifically, it relates to a cryogenic fluid cold energy storage device. Background Art

[0002] With the rapid development of industrialization, energy issues have gradually become a key factor restricting economic development. How to store energy efficiently has become a key issue that needs to be solved in industry. Cold storage technology is to store the sensible heat or latent heat released by the change of working fluid state, so as to solve the contradiction of uneven distribution of energy in time and space. It has been widely used in various fields of the national economy.

[0003] At present, most of the existing cold storage devices are still based on ice storage and water energy storage devices. These devices have complex systems, large footprints, short lifespans, low efficiency, and poor economic benefits, which have great limitations. This device uses the latent heat of phase change of materials to store cold, and has the advantages of high energy storage density, constant temperature, and high thermal efficiency. At the same time, since the energy storage density of phase change materials is significantly higher than that of the sensible heat storage system of water, the device has a compact structure, low heat loss, and has great application prospects. Summary of the invention

[0004] The present invention is aimed at the deficiencies existing in the above-mentioned background technology and provides a phase change cold storage device with a vortex coil. The device is efficient and reliable, and has the advantages that: under the influence of the baffle, when the low-temperature fluid flows in the shell, it will periodically change direction along the axial direction, thereby increasing the degree of turbulence and improving the heat transfer coefficient. At the same time, the phase change material is stored in a compact vortex coil, which has the characteristics of a large filling volume. The special vortex structure will also cause the internal fluid to produce a secondary flow, thereby enhancing the heat exchange between the fluid in the tube and the tube wall. In addition, the phase change material has a wide range of sources, has a large phase change latent heat, good thermal stability and chemical stability, is environmentally friendly, safe and reliable, and can be reused many times.

[0005] To solve the above technical problems, the present invention is implemented through the following technical solutions: a phase change cold storage device with a vortex coil, comprising an inlet pipe, an outlet pipe, a tube sheet, a baffle, a vortex coil, a cylinder, a center pipe, a support frame, a head and a saddle, the tube sheet is fixedly connected to the cylinder, the lower end position and the center position of the tube sheet are respectively opened, the inlet pipe and the outlet pipe are respectively connected to the openings at the lower end position and the center position of the tube sheet, the baffle and the vortex coil are installed on the center pipe, one end of the center pipe is fixed to the tube sheet, and the other end is inserted into the support frame connected to the cylinder, the head is connected to the cylinder, and is arranged on the other side opposite to the inlet pipe and the outlet pipe, and the saddle is arranged below the cylinder.

[0006] A number of vortex coils are installed between the baffles, and the number of the vortex coils can be determined according to the actual cold storage capacity; the baffles can change the flow direction of the low-temperature fluid in the shell and enhance heat transfer; the baffle has a central opening, and the overall shape is an arch or a disc-ring; the spacing of the baffles can be determined according to the properties of the medium, the flow rate and the size of the device, and is generally not less than one-fifth of the length of the cylinder, and the size of the central opening is determined according to the diameter of the central tube.

[0007] The central tube can be a single tube or a double tube structure; when the central tube is a double tube structure, it mainly includes an outer tube, an inner tube, an annular tube sheet and fins nested between the inner tube and the outer tube; the phase change material is filled between the inner tube and the outer tube.

[0008] The fins may be circular fins, spiral fins, corrugated fins, pin-shaped fins, etc.

[0009] The support frame is composed of a sleeve and supporting ribs. The number of supporting ribs can be determined according to actual conditions. The diameter of the sleeve is slightly larger than the diameter of the central tube.

[0010] The vortex coil is composed of a gasket strip, a gasket ring, a support ring, a base gasket strip and a coil.

[0011] Preferably, the outer diameter of the coil may be Φ19 mm, Φ25 mm, Φ32 mm or other common heat exchange tube sizes.

[0012] The coil rings are spot welded with gaskets, and the thickness of the gaskets can be determined according to actual conditions, generally ~mm.

[0013] The inner ring of the coil is evenly fixed by gaskets and spot welded on the support ring, and then the gaskets are welded circle by circle along the radial direction based on this as the base; when the coil is wound a number of times, gasket strips are evenly added circumferentially between the gaskets and used as the additional base, and the gaskets are continuously welded from the next circle, and the gaskets are finally distributed radially along the plane in a staged and increasing manner.

[0014] The initial position and number of the gasket strips can be determined according to the overall size of the vortex coil; the gasket strips are straight and have the same thickness as the gasket ring.

[0015] The inner diameter of the support ring is the same as the outer diameter of the central tube; the thickness of the support ring is consistent with that of the gasket ring, and the length is slightly larger than the outer diameter of the coil.

[0016] The gap between the support ring and the inner ring of the coil needs to be padded with a base pad, and the thickness of the base pad needs to be determined in combination with the outer diameter of the coil.

[0017] The phase change material in the coil is selected according to the temperature range of application, and can be an organic or inorganic phase change material, or a composite phase change material.

[0018] Preferably, the phase change material in the coil mainly includes organic phase change materials such as octanoic acid, nonanoic acid, decanoic acid, dodecanol, tert-amyl alcohol, ethylene glycol, n-dodecane, n-tetradecane, n-pentadecane, n-hexadecane, or inorganic phase change materials such as NaSO·HO and GeSbTe, and can also be a composite phase change material composed of two or more materials.

[0019] The fluid in the shell side is a low-temperature fluid, and its inlet temperature is lower than the phase change temperature of the phase change material in the coil.

[0020] Preferably, the cryogenic fluid medium may be ammonia, methane, nitrogen or the like.

[0021] The outer wall of the cylinder is wrapped with a heat-insulating layer made of heat-insulating material.

[0022] The tube material of the coil and the plate material of the baffle may be different, ranging from carbon steel, stainless steel, steel and steel alloys, aluminum and aluminum alloys, copper and copper alloys and other special metals.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. Compared with other cold storage media, latent heat phase change materials have a large cold storage density, suitable cold storage temperature, and good adaptability to cold load changes. In the same temperature range, its cold storage capacity is greater than the sensible heat of water. Compared with ice storage, it has the advantage of maintaining fluidity. At the same time, phase change materials are widely available, have good thermal and chemical stability, are safe and reliable, and can be reused many times.

[0025] 2. The vortex coil has a compact structure and is easy to install. Compared with conventional round tubes, it has a large filling volume and a large heat exchange area. Its special structure will generate secondary flow inside, thereby strengthening the heat exchange between the fluid in the tube and the tube wall and improving the utilization rate of the cooling capacity.

[0026] 3. The device has a simple structure and is easy to manufacture. The center tube is inserted into the support frame on the side close to the head. It is a detachable structure that allows the center tube to be easily inserted into or pulled out of the shell. At the same time, when the temperature difference between the phase change material and the cryogenic fluid is large, the center tube can be freely expanded and contracted along the axial direction, completely eliminating the temperature difference stress.

[0027] 4. The baffles are set in the device to control the flow direction of the fluid, so that the fluid can continuously change direction along the axial direction, which can further increase the turbulence and improve the heat transfer coefficient.

[0028] 5. The installation can be done in units of coils, which is convenient. At the same time, the number of coils required can be increased or decreased according to the actual demand for cold storage, and has a wide range of applications.

[0029] 6. A wide range of pipes and plates are available, mainly including carbon steel, stainless steel, steel and steel alloys, aluminum and aluminum alloys, copper and copper alloys and other special metals.

[0030] 7. The cryogenic fluid enters from the inlet pipe, changes direction along the axial direction, flows back through the pipe opening of the center pipe close to the head side, and is finally discharged from the outlet pipe, which greatly prolongs the heat exchange time between the cryogenic fluid and the phase change material in the cold storage device.

[0031] 8. Gaskets are used to weld between coil circles. On the one hand, the coil can be fixed as a whole. On the other hand, the spacing between adjacent coils can be controlled by adjusting the thickness of the gaskets. This is an effective means to control the pitch and spacing of the coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic plan view of a phase change cold storage device with a vortex coil according to the present invention.

[0033] Figure 2 It is a three-dimensional schematic diagram of a phase-change cold storage device with a vortex coil according to the present invention.

[0034] Figure 3 The diagram is a schematic structural diagram of a baffle in a phase-change cold storage device with a vortex coil according to the present invention.

[0035] Figure 4 It is a schematic diagram of the phase change cold storage device with a vortex coil of the present invention when the central tube is a double-tube structure.

[0036] Figure 5 The figure is a schematic diagram of the support frame structure of the phase change cold storage device with a vortex coil according to the present invention.

[0037] Figure 6 The figure is a schematic diagram of the spiral coil structure of the phase change cold storage device with the spiral coil of the present invention.

[0038] Figure 7 It is a schematic diagram of the gasket ring of the phase change cold storage device with a vortex coil of the present invention.

[0039] In the figure: 1—inlet pipe; 2—outlet pipe; 3—tube sheet; 4—baffle; 5—vortex coil; 6—cylinder; 7—center pipe; 8—support frame; 9—head; 10—saddle; 11—outer pipe; 12—inner pipe; 13—annular tube sheet; 14—fin; 15—sleeve; 16—support rib; 17—gasket; 18—gasket ring; 19—support ring; 20—base gasket; 21—coil. DETAILED DESCRIPTION

[0040] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner.

[0041] like Figure 1 , 2 As shown, the phase change cold storage device with vortex coils of this embodiment comprises an inlet pipe 1, an outlet pipe 2, a tube sheet 3, a cylinder 6, a central tube 7, a support frame 8, a head 9, a saddle 10, and a baffle 4 and a vortex coil 5 installed on the central tube 7; a plurality of vortex coils 5 are installed between the baffles 4, and the number of the vortex coils 5 can be determined according to the actual cold storage capacity; the baffle 4 can change the flow direction of the low-temperature fluid in the shell and enhance the heat transfer; the tube sheet 3 is welded to the cylinder 6, and holes are opened at the lower end and the center of the tube sheet 3 respectively, and the inlet pipe 1 and the outlet pipe 2 are welded to serve as the inlet and outlet of the low-temperature fluid; the low-temperature fluid medium can be methane, ammonia, nitrogen, etc., and its inlet temperature is lower than the phase change temperature of the phase change material in the coil 21; one end of the central tube 7 is fixed on the tube sheet 3, and the other end is inserted into the support frame 8 welded to the cylinder 6; the central tube 7 can be a single tube or a double tube structure;

[0042] like Figure 3 As shown, the baffle 4 has a central opening, and the overall shape is bow-shaped or disc-ring-shaped; the spacing of the baffles 4 can be determined according to the properties of the medium, the flow rate and the size of the device, and is generally not less than one-fifth of the length of the cylinder. The size of the central opening can be determined according to the diameter of the central tube 7; the outer wall of the cylinder 6 is wrapped with an insulating layer composed of insulating material.

[0043] like Figure 4 As shown, when the central tube 7 is a double-tube structure, it mainly includes an outer tube 11, an inner tube 12, an annular tube sheet 13, and a fin 14 nested between the inner tube 12 and the outer tube 11; the inner tube 12 and the outer tube 11 are filled with a phase change material, and the fin 14 can be a circular fin, a spiral fin, a corrugated fin, a needle fin, etc.; the low-temperature fluid refluxes through the central tube 7, which greatly increases the heat exchange time with the phase change material in the cold storage device and improves the heat exchange efficiency;

[0044] like Figure 5 As shown, the support frame 8 is composed of a sleeve 15 and a support rib 16. The number of the support ribs 16 can be determined according to actual conditions. The diameter of the sleeve 15 is slightly larger than the diameter of the center tube 7. The support ribs 16 are welded to the cylinder 6 to support the center tube 7. The side of the center tube 7 close to the head 9 is sleeved on the sleeve 15, which is a detachable structure, so that the center tube can be easily inserted into or withdrawn from the shell. At the same time, when the temperature difference between the phase change material and the cryogenic fluid is large, the center tube 7 can freely expand and contract along the axial direction, completely eliminating the temperature difference stress.

[0045] like Figure 6 , 7As shown, the vortex coil 5 is composed of a gasket 17, a gasket ring 18, a support ring 19, a base gasket 20 and a coil 21. The outer diameter of the coil 21 can be Φ19mm, Φ25mm, Φ32mm and other common heat exchange tube sizes; both ends of the coil 21 are blocked, and the inside contains a phase change material; the phase change material can be selected according to the temperature range of application, mainly including organic phase change materials such as octanoic acid, nonanoic acid, decanoic acid, dodecanol, tert-amyl alcohol, ethylene glycol, n-dodecane, n-tetradecane, n-pentadecane, n-hexadecane, or Na 2 SO 4 10H 2 O. Ge 1 Sb 2 Te 4 Inorganic phase change materials such as phase change materials can also be composite phase change materials composed of two or more materials; the phase change material has a large cold storage density, a suitable cold storage temperature, good adaptability to cold load changes, and a wide source. It has good thermal stability and chemical stability, is safe and reliable, and can be reused many times; the gasket 18 is welded between the coils 21, and the thickness of the gasket 18 can be determined according to actual conditions, generally 1 to 5 mm;

[0046] The inner circle of the coil 21 is evenly fixed by four gaskets 18 and spot welded on the support ring 19, and then the gaskets 18 are welded radially circle by circle based on this as the base; when the coil 21 is wound for several times, the gasket strips 17 are evenly added between the gaskets 18 and used as the additional base, and the gaskets 18 are continuously spot welded from the next circle, and the gaskets 18 are finally distributed radially along the plane in a staged increasing manner; the position and number of the gasket strips 17 added can be determined according to the overall size of the spiral coil 5; ... the gaskets 17 are evenly added between the gaskets 18 and the gaskets 18 are evenly added between the gaskets 18 and the gaskets 18 are evenly added. 7 is straight, and its thickness is consistent with that of the gasket 18; the inner diameter of the support ring 19 is the same as the outer diameter of the center tube 7, its thickness is consistent with that of the gasket 18, and its length is slightly larger than the outer diameter of the coil 21; the gap between the support ring 19 and the inner circle of the coil 21 needs to be padded with a base gasket strip 20, and the thickness of the base gasket strip 20 needs to be determined in combination with the outer diameter of the coil 21; the pipe and plate materials can be inconsistent, and the range includes carbon steel, stainless steel, steel and steel alloys, aluminum and aluminum alloys, copper and copper alloys and other special metals.

[0047] The phase change cold storage device with a vortex coil provided by the present invention has a compact structure, is highly efficient and reliable, and has a wide range of applications. When the cryogenic fluid flows in the shell, the fluid will periodically change direction under the influence of the baffle, thereby increasing the degree of turbulence and improving the heat transfer coefficient. At the same time, the special structure of the vortex coil can, on the one hand, increase the filling amount of the phase change material, and on the other hand, it will also cause the internal fluid to generate a secondary flow, thereby strengthening the heat exchange between the fluid in the tube and the tube wall. In addition, the return of the cryogenic fluid through the central tube greatly increases the heat exchange time with the phase change material in the cold storage device, thereby improving the heat exchange efficiency.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A phase-change cold storage device with a vortex coil, characterized in that: The invention comprises an inlet pipe (1), an outlet pipe (2), a tube sheet (3), a baffle (4), a vortex coil (5), a cylinder (6), a center pipe (7), a support frame (8), a head (9) and a saddle (10), wherein the tube sheet (3) is fixedly connected to the cylinder (6), a hole is respectively opened at the lower end position and the center position of the tube sheet (3), the inlet pipe (1) and the outlet pipe (2) are respectively connected to the holes at the lower end position and the center position of the tube sheet (3), the baffle (4) and the vortex coil (5) are installed on the center pipe (7), one end of the center pipe (7) is fixed to the tube sheet (3), and the other end is inserted into the support frame (8) connected to the cylinder (6), the head (9) is connected to the cylinder (6) and is arranged on the other side opposite to the inlet pipe (1) and the outlet pipe (2), the outlet pipe is connected to the center pipe, and the saddle (10) is arranged below the cylinder (6); The support frame (8) is composed of a sleeve (15) and a support rib plate (16); the support rib plate (16) is welded to the cylinder (6); the diameter of the sleeve (15) is slightly larger than the diameter of the central tube (7).

2. The phase-change cold storage device with a vortex coil according to claim 1, characterized in that: The baffle plates (4) are N in number, N≥2, and M vortex coils (5) are installed between every two baffle plates (4), M≥4; the baffle plates (4) have a central opening, and are in an arcuate or disc-ring shape as a whole; the size of the central opening is adapted to the diameter of the central tube (7).

3. The phase-change cold storage device with a vortex coil according to claim 1, characterized in that: The vortex coil (5) comprises a gasket strip (17), a gasket ring (18), a support ring (19), and a coil (21); the gasket rings (18) are welded between the coils (21); four gasket rings (18) are evenly and fixedly arranged on the inner ring of the coil (21) and spot-welded on the support ring (19); gasket strips (17) are evenly arranged between the gasket rings (18) along the circumferential direction; the gasket rings (18) are finally distributed radially in a step-by-step increasing manner along a plane; and the thickness of the gasket rings (18) is 1 to 5 mm.

4. The phase-change cold storage device with a vortex coil according to claim 3, characterized in that: The coil (21) is sealed at both ends and contains phase change material inside; a base gasket (20) is provided in the gap between the support ring (19) and the inner ring of the coil (21), and the thickness of the base gasket (20) is adapted to the outer diameter of the coil (21); the gasket (17) is straight, and the inner diameter of the support ring (19) is the same as the outer diameter of the center tube (7); the support ring (19) is the same thickness as the gasket (17) and the gasket ring (18), and its length is slightly greater than the outer diameter of the coil (21).

5. The phase-change cold storage device with a vortex coil according to claim 1, characterized in that: The central tube (7) is a single tube or double tube structure; when the central tube (7) is a double tube structure, it comprises an outer tube (11), an inner tube (12), an annular tube sheet (13), and fins (14) nested between the inner tube (12) and the outer tube (11); and phase change material is filled between the inner tube (12) and the outer tube (11).

6. The phase-change cold storage device with a vortex coil according to claim 5, characterized in that: The fins (14) are circular fins, spiral fins, corrugated fins or needle fins.

7. The phase-change cold storage device with a vortex coil according to claim 1, characterized in that: The outer wall of the cylinder (6) is wrapped with a heat-insulating layer made of heat-insulating material.

8. The phase-change cold storage device with a vortex coil according to claim 4, characterized in that: The phase change material in the coil (21) and the central tube (7) is an organic phase change material, an inorganic phase change material or a composite phase change material; the organic phase change material is octanoic acid, nonanoic acid, decanoic acid, dodecanol, tert-amyl alcohol, ethylene glycol, n-dodecane, n-tetradecane, n-pentadecane or n-hexadecane, and the inorganic phase change material is Na2SO4·10H2O or Ge1Sb2Te4.

9. The phase-change cold storage device with a vortex coil according to claim 8, characterized in that: The fluid in the device is a low-temperature fluid, and its inlet temperature is lower than the phase change temperature of the phase change material in the coil (21) and the central tube (7).

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