A three-fluid shell-and-tube heat exchanger
By integrating refrigerant, circulating water and steam into a three-fluid shell-and-tube heat exchanger, the problems of equipment complexity and energy loss in existing low-temperature heat pump crystallization equipment are solved, achieving structural simplification and efficiency improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- KUNSHAN WSD ENVIRONMENTAL PROTECTION EQUIP CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-07-31
AI Technical Summary
In existing low-temperature heat pump crystallization equipment, secondary steam cooling requires multiple heat exchangers connected in series, resulting in complex equipment, large footprint, and energy loss.
The three-fluid shell-and-tube heat exchanger integrates the heat exchange processes of refrigerant, circulating water and steam into a single shell. The design of spiral refrigerant and circulating water tube bundles and baffles simplifies the structure and enhances the heat exchange effect.
It effectively simplifies the structure of the heat exchange system, reduces the floor space, improves heat exchange efficiency, and ensures the stable operation of the heat pump system.
Smart Images
Figure CN224580760U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heat exchanger technology, and in particular to a three-fluid shell-and-tube heat exchanger. Background Technology
[0002] Low-temperature crystallization skid-mounted equipment utilizing a heat pump system meets the market's urgent demand for efficient, energy-saving, and convenient wastewater treatment equipment. In low-temperature heat pump crystallization equipment, the cooling of secondary steam typically requires sequential heat exchange with the refrigerant through a dry evaporator and with circulating water through an auxiliary cooler to ensure complete cooling.
[0003] like Figure 1 As shown, in existing secondary steam cooling systems in separator 100, the heat exchanger typically employs a shell-and-tube heat exchanger with two fluid streams, including a main heat exchanger 300 for refrigerant-steam heat exchange and an auxiliary heat exchanger 200 for circulating water-steam heat exchange. Secondary steam exits from the steam outlet 101 of separator 100, enters the main heat exchanger 300 for heat exchange and cooling, and then condensate flows out from the corresponding main outlet 400. The main heat exchanger 300 is equipped with refrigerant inlet and outlet 301 for refrigerant flow. When needed, the valve connecting separator 100 to auxiliary heat exchanger 200 is opened, allowing secondary steam exiting from the steam outlet 101 of separator 100 to enter the auxiliary heat exchanger 200 for heat exchange and cooling. Then, condensate flows out from the corresponding main outlet 400. The auxiliary heat exchanger 200 is equipped with circulating water inlet and outlet 201 for circulating water flow.
[0004] Existing cooling methods have the following problems:
[0005] The equipment is complex: it requires multiple heat exchangers to be used in series, which increases the complexity of the equipment and the floor space required.
[0006] Energy loss: When switching between multiple heat exchangers to transfer heat, there is energy loss, which reduces the overall efficiency of the system. Utility Model Content
[0007] To address the aforementioned issues, this application provides a structurally sound three-fluid shell-and-tube heat exchanger, thereby effectively simplifying the heat exchange system structure, reducing the floor space required, and ensuring heat exchange performance.
[0008] The technical solution adopted in this utility model is as follows:
[0009] A three-fluid shell-and-tube heat exchanger includes an outer shell with a steam inlet and a condensate outlet at its two ends. A central cylinder is coaxially arranged inside the outer shell, and a refrigerant tube bundle and a circulating water tube bundle are spirally wound around the central cylinder along the axial direction. The circumferential wall of the outer shell is equipped with a refrigerant outlet and a refrigerant inlet communicating with both ends of the refrigerant tube bundle, and a circulating water outlet and a circulating water inlet communicating with both ends of the circulating water tube bundle. The refrigerant outlet and the circulating water outlet are arranged close to the steam inlet, and the refrigerant inlet and the circulating water inlet are arranged close to the condensate outlet.
[0010] As a further improvement to the above technical solution:
[0011] The refrigerant pipe bundles are stranded to form a spiral structure, and the circulating water pipe bundles are stranded to form a spiral structure. The spiral directions of the refrigerant pipe bundles and the circulating water pipe bundles are the same.
[0012] The number of pipes in the refrigerant pipe bundle is greater than the number of pipes in the circulating water pipe bundle, and the circulating water pipe bundle is wrapped around the outside of the refrigerant pipe bundle.
[0013] The outer surface of the refrigerant pipe bundle with a spiral structure forms a spiral groove, and the circulating water pipe bundle with a spiral structure is installed in the spiral groove.
[0014] It also includes baffles, which are spirally wound and mounted on the central cylinder. The baffles have holes through which each pipe in the refrigerant bundle and each pipe in the circulating water bundle can pass.
[0015] The helical direction of the baffle plate is opposite to that of the refrigerant pipe bundle and the circulating water pipe bundle.
[0016] The inner edge of the baffle plate is welded to the outer wall of the central cylinder, and the outer edge of the baffle plate is welded to the inner wall of the outer shell.
[0017] Each pipe in the refrigerant pipe bundle has an end plate installed at both ends. The end plate is fitted onto the outer wall of the outer casing, and a through hole is provided on the end plate for connecting the pipes.
[0018] Each pipe in the circulating water pipe bundle has a second end plate installed at both ends. The second end plate is fitted onto the outer wall of the outer casing, and a through hole is provided on the second end plate for connecting the pipes.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] When this utility model is in use, secondary steam enters the outer shell through the steam inlet and exchanges heat with the refrigerant in the refrigerant tube bundle. The secondary steam releases heat to form condensate, which flows downward from the condensate outlet. When needed, it also exchanges heat with the circulating water in the circulating water tube bundle and the secondary steam to ensure the stable operation of the heat pump system. It effectively simplifies the structure of the heat exchange system, reduces the floor space, and ensures the heat exchange effect.
[0021] This utility model also has the following advantages:
[0022] By integrating the heat exchange processes of refrigerant, circulating water and steam into a single housing, heat exchange efficiency is ensured while effectively reducing the number of heat exchangers and improving overall efficiency.
[0023] The spiral baffles create a spiral channel for secondary steam to flow downwards inside the outer shell, which helps to enhance the heat exchange effect between the secondary steam, refrigerant, and circulating water. Attached Figure Description
[0024] Figure 1 This is a layout diagram of the existing cooling equipment used for secondary steam in the separator.
[0025] Figure 2 This is a layout diagram of the secondary steam cooling system for a separator using a three-fluid shell-and-tube heat exchanger.
[0026] Figure 3 This is a structural diagram of the three-fluid shell-and-tube heat exchanger of this utility model.
[0027] Figure 4 This is a schematic diagram of the structure of this utility model, omitting the outer shell.
[0028] Figure 5 This is a schematic diagram showing the layout of the refrigerant pipe bundle and circulating water pipe bundle of this utility model.
[0029] Figure 6 This is a schematic diagram showing the arrangement of the central cylinder and baffles of this utility model.
[0030] Wherein: 100, separator; 101, steam outlet; 200, auxiliary heat exchanger; 201, circulating water inlet and outlet; 300, main heat exchanger; 301, refrigerant inlet and outlet; 400, main outlet; 500, three-fluid heat exchanger;
[0031] 1. Outer shell; 2. Refrigerant piping bundle; 3. Central cylinder; 4. Circulating water piping bundle; 5. Baffle plate;
[0032] 11. Steam inlet; 12. Condensate outlet; 13. Circulating water outlet; 14. Circulating water inlet; 15. Refrigerant outlet; 16. Refrigerant inlet;
[0033] 20. Spiral groove; 21. End plate one; 41. End plate two. Detailed Implementation
[0034] The specific embodiments of this utility model are described below with reference to the accompanying drawings.
[0035] like Figure 2As shown, the steam outlet 101 of the separator 100 is connected to the three-fluid heat exchanger 500. By using the three-fluid heat exchanger 500, the connection of the existing two sets of shell and tube heat exchangers can be replaced, which effectively simplifies the cooling system structure of the cooling separator 100 and reduces the floor space.
[0036] like Figure 3 and Figure 4 As shown, a three-fluid shell-and-tube heat exchanger of this embodiment includes an outer shell 1, with a steam inlet 11 and a condensate outlet 12 at both ends of the outer shell 1. A central cylinder 3 is coaxially arranged inside the outer shell 1, and a refrigerant tube bundle 2 and a circulating water tube bundle 4 are spirally wound around the central cylinder 3 along the axial direction. A refrigerant outlet 15 and a refrigerant inlet 16 communicating with both ends of the refrigerant tube bundle 2 are mounted on the circumferential wall of the outer shell 1, and a circulating water outlet 13 and a circulating water inlet 14 communicating with both ends of the circulating water tube bundle 4. The refrigerant outlet 15 and the circulating water outlet 13 are arranged close to the steam inlet 11, and the refrigerant inlet 16 and the circulating water inlet 14 are arranged close to the condensate outlet 12.
[0037] During use, secondary steam enters the outer casing 1 through steam inlet 11 and exchanges heat with the refrigerant in the refrigerant tube bundle 2. The secondary steam releases heat to form condensate, which flows downward from the condensate outlet 12. When needed, it also exchanges heat with the circulating water in the circulating water tube bundle 4 to ensure the stable operation of the heat pump system. This effectively helps to simplify the structure of the separator 100 cooling system and effectively ensures the heat exchange effect.
[0038] In this embodiment, the heat exchange processes of refrigerant, circulating water and steam are integrated into a single housing, ensuring heat exchange efficiency while effectively reducing the number of heat exchangers and improving overall utilization efficiency.
[0039] like Figure 5 As shown, the refrigerant tube bundle 2 is formed into a spiral structure, and the circulating water tube bundle 4 is formed into a spiral structure. The spiral directions of the refrigerant tube bundle 2 and the circulating water tube bundle 4 are the same. Thus, the heat exchange and cooling of the steam in the outer shell 1 can be achieved by the refrigerant in the refrigerant tube bundle 2 and the circulating water in the circulating water tube bundle 4, either alone or in combination.
[0040] Meanwhile, in this embodiment, the refrigerant tube bundle 2 and the circulating water tube bundle 4 arranged in the same spiral direction ensure the heat exchange effect while also making the overall structural layout compact.
[0041] The number of pipes in the refrigerant pipe bundle 2 is greater than the number of pipes in the circulating water pipe bundle 4. The circulating water pipe bundle 4 is wrapped around the outside of the refrigerant pipe bundle 2. This effectively ensures that the refrigerant plays a dominant and primary role in heat exchange, while the circulating water serves as an auxiliary and supplementary element in the cooling process.
[0042] The outer surface of the refrigerant tube bundle 2 with a spiral structure forms a spiral groove 20. The circulating water tube bundle 4 with a spiral structure is installed in the spiral groove 20, so as to achieve a compact arrangement of the refrigerant tube bundle 2 and the circulating water tube bundle 4 inside the outer shell 1. Furthermore, the reasonable and ingenious spiral embedding helps to ensure the heat exchange effect.
[0043] It also includes baffle 5, such as Figure 6 As shown, the baffle plate 5 is wound and mounted on the central cylinder 3 in a spiral direction. The baffle plate 5 has holes for each pipe in the refrigerant pipe bundle 2 and each pipe in the circulating water pipe bundle 4 to pass through.
[0044] In this embodiment, the spiral baffle 5 forms a spiral channel for secondary steam to flow downward inside the outer shell 1, which helps to enhance the heat exchange effect between secondary steam and refrigerant and circulating water.
[0045] The spiral direction of the baffle 5 is opposite to that of the refrigerant tube bundle 2 and the circulating water tube bundle 4; thus, while increasing the heat exchange tube length through the spiral structure, the opposite spiral arrangement ensures the heat exchange effect.
[0046] The inner edge of the baffle plate 5 is welded to the outer wall of the central cylinder 3, and the outer edge of the baffle plate 5 is welded to the inner wall of the outer shell 1. Thus, the baffle plate 5 forms an effective spiral channel for steam flow and effectively ensures the structural reliability of the baffle plate 5 and the central cylinder 3 inside the outer shell 1.
[0047] Each pipe in the refrigerant pipe bundle 2 has an end plate 21 installed at both ends. The end plate 21 is fitted onto the outer wall of the outer casing 1, and a through hole is provided on the end plate 21 for connecting the pipes.
[0048] Each pipe in the circulating water pipe bundle 4 has an end plate 41 installed at both ends. The end plate 41 is fitted onto the outer wall of the outer casing 1, and a through hole is provided on the end plate 41 for connecting the pipes.
[0049] In this embodiment, the arrangement of end plate 21 and end plate 41 effectively ensures the structural reliability of the refrigerant tube bundle 2 and circulating water tube bundle 4 inside the outer shell 1, and effectively ensures that the refrigerant tube bundle 2 and circulating water tube bundle 4 each form a spiral structure.
[0050] In this embodiment, fins, such as needle-shaped fins, can also be provided on each tube in the refrigerant tube bundle 2 to further increase the heat transfer area on the tube side, and the staggered arrangement of the fins increases the disturbance and enhances the turbulence, thereby improving the heat transfer coefficient of the refrigerant tube bundle 2.
[0051] In this embodiment, to meet the requirements of steam cooling in the separator 100, temperature and pressure sensors can be installed on the refrigerant inlet and outlet pipes to monitor the refrigerant temperature and pressure in real time and transmit the data to the intelligent control system. When an increase in refrigerant pressure is detected, the intelligent control system not only controls the opening of the circulating water valve but also precisely adjusts the butterfly valve opening according to the rate and magnitude of pressure change to control the flow rate of the circulating water, matching it with the refrigerant pressure change and ensuring that the system is always in a highly efficient and stable operating state.
[0052] The method of using this utility model is as follows:
[0053] Secondary steam enters the shell side of the three-fluid heat exchanger 500 through steam inlet 11 and exchanges heat with the refrigerant in the refrigerant tube bundle 2 inside the shell 1. The secondary steam releases heat, and the refrigerant absorbs heat. When the refrigerant inlet pressure rises to the set value, the butterfly valve corresponding to the circulating water inlet 14 automatically opens, allowing the secondary steam inside the shell 1 to exchange heat with the refrigerant in the refrigerant tube bundle 2 and the circulating water in the circulating water tube bundle 4, respectively. The circulating water absorbs part of the heat from the secondary steam, thereby effectively helping to reduce the evaporation temperature of the heat pump system and ensuring stable system operation.
[0054] This invention effectively simplifies the structure of the heat exchange system, reduces the floor space required, and ensures the heat exchange effect.
[0055] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0056] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.
Claims
1. A three-fluid shell-and-tube heat exchanger comprising an outer housing (1), characterized in that: The outer shell (1) has a steam inlet (11) and a condensate outlet (12) at both ends. A central cylinder (3) is coaxially arranged inside the outer shell (1). A refrigerant tube bundle (2) and a circulating water tube bundle (4) are spirally wound around the central cylinder (3) along the axial direction. The outer shell (1) is equipped with a refrigerant outlet (15) and a refrigerant inlet (16) that are connected to both ends of the refrigerant tube bundle (2), and a circulating water outlet (13) and a circulating water inlet (14) that are connected to both ends of the circulating water tube bundle (4). The refrigerant outlet (15) and the circulating water outlet (13) are arranged close to the steam inlet (11), and the refrigerant inlet (16) and the circulating water inlet (14) are arranged close to the condensate outlet (12).
2. A three-fluid shell-and-tube heat exchanger as claimed in claim 1, characterized in that: The refrigerant pipe bundle (2) is formed into a spiral structure, and the circulating water pipe bundle (4) is formed into a spiral structure. The spiral directions of the refrigerant pipe bundle (2) and the circulating water pipe bundle (4) are the same.
3. A three-fluid shell-and-tube heat exchanger as claimed in claim 1, characterized in that: The number of pipes in the refrigerant pipe bundle (2) is greater than the number of pipes in the circulating water pipe bundle (4), and the circulating water pipe bundle (4) is wrapped around the outside of the refrigerant pipe bundle (2).
4. A three-fluid shell-and-tube heat exchanger as claimed in claim 1, characterized in that: The outer surface of the refrigerant pipe bundle (2) with a spiral structure forms a spiral groove (20), and the circulating water pipe bundle (4) with a spiral structure is fitted in the spiral groove (20).
5. A three-fluid shell-and-tube heat exchanger as claimed in claim 1, wherein: It also includes a baffle plate (5), which is wound and mounted on the central cylinder (3) in a spiral direction. The baffle plate (5) has holes for each pipe in the refrigerant bundle (2) and each pipe in the circulating water bundle (4) to pass through.
6. A three-fluid shell-and-tube heat exchanger as claimed in claim 5, characterized in that: The spiral direction of the baffle (5) is opposite to that of the refrigerant pipe bundle (2) and the circulating water pipe bundle (4).
7. A three-fluid shell-and-tube heat exchanger as claimed in claim 5, characterized in that: The inner edge of the baffle plate (5) is welded to the outer wall of the central cylinder (3), and the outer edge of the baffle plate (5) is welded to the inner wall of the outer shell (1).
8. A three-fluid shell-and-tube heat exchanger as defined in claim 1, wherein: Each pipe in the refrigerant pipe bundle (2) has an end plate (21) installed at both ends. The end plate (21) is fitted onto the outer wall of the outer casing (1). Through holes are provided on the end plate (21) for connecting the pipes.
9. A three-fluid shell-and-tube heat exchanger as claimed in claim 1, wherein: Each pipe in the circulating water pipe bundle (4) is equipped with a second end plate (41) at both ends. The second end plate (41) is fitted onto the outer wall of the outer shell (1). Through holes are provided on the second end plate (41) for connecting the pipes.