Separating type heat pipe molten salt heat exchanger
The molten salt heat exchanger designed by the separated heat pipe solves the problems of temperature difference stress and freezing blockage, and achieves efficient molten salt heat exchange, which is not limited by the temperature of the cold fluid, and has the convenience of maintenance of grouping.
Patent Information
- Application Number
- CN202421166087.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-27
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-05-27
AI Technical Summary
Existing molten salt heat exchangers are prone to temperature differential stress during the large temperature difference heat exchange process, resulting in cracking of the weld port and damage to the heat exchanger. At the same time, they are prone to freezing and blocking. When the temperature of the cold fluid is lower than the freezing point of the molten salt, the heat exchange efficiency is low.
The separated heat pipe molten salt heat exchanger is adopted. Through the separation design of the evaporator and the condenser, the structure of the steam tank and the condenser is used to achieve the temperature of the working fluid liquid close to the saturation temperature, the heat transfer density is high, and the temperature difference stress is avoided. The setting of the shut-off valve and the exhaust valve is used to prevent cold working fluid or cold air from entering the evaporator.
It effectively prevents molten salt from solidifying, avoids temperature difference stress and freezing, improves heat exchange efficiency, is not limited by the temperature of cold fluid, and the evaporator can be set in groups for easy maintenance and replacement.
Smart Images
Figure CN222799737U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a separated heat pipe molten salt heat exchanger, belonging to the technical field of heat exchangers. Background Art
[0002] Under the background of carbon neutrality, as the proportion of renewable energy continues to increase, the application of molten salt energy storage technology in the consumption of new energy and the flexibility transformation of thermal power units has received more and more attention. Molten salt has the characteristics of wide temperature range, high energy storage density, low viscosity, good fluidity and high safety, and has great advantages in the field of large-capacity and long-term energy storage.
[0003] As one of the key equipment of molten salt energy storage technology, molten salt heat exchanger has always attracted much attention. Not only the corrosiveness of molten salt is considered, but also the possibility of solidification of molten salt during heat exchange, which may cause blockage of heat exchanger. Therefore, the cold fluid inlet temperature of molten salt heat exchanger is designed to be higher than the solidification temperature of molten salt, and generally a cold fluid heater is added before molten salt heat exchanger. There is a large temperature difference between molten salt and cold fluid, and the tube or tube sheet generates large stress, which causes cracking of welds and damage to heat exchanger.
[0004] Therefore, we propose a split heat pipe molten salt heat exchanger. Utility Model Content
[0005] The utility model aims to provide a separated heat pipe molten salt heat exchanger, which can realize large temperature difference heat exchange of the molten salt heat exchanger, prevent the generation of temperature difference stress, avoid freezing and blocking, and is not limited by the temperature of the cold fluid.
[0006] To solve the above technical problems, the utility model adopts the following technical solution: a separated heat pipe molten salt heat exchanger, comprising an evaporator, the evaporator freely expands in the molten salt, the output end of the evaporator is connected to one end of a steam pipe, the other end of the steam pipe is connected to a steam box, a condenser is arranged on the top of the steam box, the condenser freely expands in the cold fluid, the bottom of the steam box is connected to one end of a condensate underwater pipe, the other end of the condensate underwater pipe is connected to a separator, the output end of the separator is connected to one end of a return pipe, and the other end of the return pipe is connected to the input end of the evaporator.
[0007] The aforementioned separate heat pipe molten salt heat exchanger also includes molten salt and cold fluid, the outer surface of the evaporator is in full contact with the molten salt, and the outer surface of the condenser is in full contact with the cold fluid.
[0008] In the aforementioned separated heat pipe molten salt heat exchanger, a safety valve is provided on the evaporator to ensure the safety of the evaporator.
[0009] In the aforementioned separated heat pipe molten salt heat exchanger, a stop valve is provided on the steam pipe, and the stop valve is closed when the heat exchanger is shut down to prevent cold working fluid or cold air from entering the evaporator and causing the molten salt to solidify.
[0010] In the aforementioned separated heat pipe molten salt heat exchanger, the condenser is provided with an exhaust valve, which is opened when the working fluid is injected and discharges non-condensable gas to establish a vacuum when the heat exchanger is running.
[0011] In the aforementioned separated heat pipe molten salt heat exchanger, one end of the steam box away from the steam pipe is connected to one end of a balancing pipe, and the other end of the balancing pipe is connected to the separator to balance the air pressure in the separator, and the steam in the separator returns to the steam box through the balancing pipe.
[0012] The aforementioned separated heat pipe molten salt heat exchanger may be equipped with a condensate circulation pump on the return pipe, and also includes a recirculation valve, which is installed on the return pipe in parallel with the condensate circulation pump. If the condenser is located lower than the evaporator, the liquid in the separator is pumped back to the evaporator through the condensate circulation pump.
[0013] The aforementioned separated heat pipe molten salt heat exchanger, the evaporator includes an upper header and a lower header, the upper header is connected to the steam pipe, the lower header is connected to the return pipe, a heat exchange tube is arranged between the upper header and the lower header, and the outer surface of the heat exchange tube is provided with a heat exchange tube fin.
[0014] In the aforementioned separated heat pipe molten salt heat exchanger, the condenser comprises a connection box, a condenser tube is arranged between the connection box and the steam box, and a condenser tube fin is arranged on the outer surface of the condenser tube.
[0015] Compared with the prior art, the separate heat pipe molten salt heat exchanger of the utility model can prevent the molten salt from solidifying. Even if the temperature of the cold fluid is lower than the solidification point of the molten salt, the unique condenser structure makes the temperature of the working fluid close to the saturation temperature, the heat transfer density is large, the layout is convenient, and it is not restricted by the position of the molten salt and the cold fluid; and the evaporator of the utility model can be arranged in groups, and each group of inlets and outlets is provided with valves. Even if the molten salt corrodes the evaporation tubes, the damaged tube group can be cut off without affecting the operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a structural schematic diagram of the utility model;
[0017] Figure 2 This is a schematic diagram of the structure of the evaporator of the utility model;
[0018] Figure 3 This is a schematic diagram of the structure of the utility model condenser
[0019] Figure 4 It is a structural schematic diagram of embodiment 5 of the present utility model.
[0020] Figure markings: 1-molten salt, 2-evaporator, 201-upper header, 202-lower header, 203-heat exchange tube, 204-heat exchange tube fin, 3-safety valve, 4-stop valve, 5-steam pipe, 6-cold fluid, 7-condenser, 701-connecting box, 702-condenser, 703-condenser fin, 8-exhaust valve, 9-steam box, 10-condensate underwater pipe, 11-balance pipe, 12-separator, 13-return pipe.
[0021] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods. DETAILED DESCRIPTION
[0022] Embodiment 1 of the utility model: A separated heat pipe molten salt heat exchanger, comprising an evaporator 2, the evaporator 2 is freely expanded in the molten salt 1, the output end of the evaporator 2 is connected to one end of a steam pipe 5, the other end of the steam pipe 5 is connected to a steam box 9, a condenser 7 is arranged on the top of the steam box 9, the condenser 7 is freely expanded in the cold fluid 6, the bottom of the steam box 9 is connected to one end of a condensate water pipe 10, the other end of the condensate water pipe 10 is connected to a separator 12, and the output end of the separator 12 is connected to a return water pipe 13 The condenser 7 is provided with a steam box 9 at the bottom, and the evaporator 2 exchanges heat with the molten salt 1 to generate steam. The working fluid steam from the evaporator 2 first enters the steam box 9, and rises under the action of the pressure difference to enter the condenser tube 702, and exchanges heat with the cold fluid 5 to condense into liquid. The working fluid liquid falls to the bottom of the steam box 9. The liquid contacts with the steam during the falling process to reduce the degree of supercooling, and maintains a temperature close to the saturation temperature of the working fluid, so that the molten salt evaporator does not freeze and block, and the molten salt heat exchanger is not limited by the temperature of the cold fluid.
[0023] Embodiment 2 of the utility model: A separated heat pipe molten salt heat exchanger, comprising an evaporator 2, the evaporator 2 is freely expanded in the molten salt 1, the evaporator 2 is provided with a safety valve 3 to ensure the safety of the evaporator, the output end of the evaporator 2 is connected to one end of a steam pipe 5, the other end of the steam pipe 5 is connected to a steam box 9, a condenser 7 is provided on the top of the steam box 9, the condenser 7 is freely expanded in the cold fluid 6, the bottom of the steam box 9 is connected to one end of a condensate underwater pipe 10, the other end of the condensate underwater pipe 10 is connected to a separator 12, the output end of the separator 12 is connected to one end of a return pipe 13, the return pipe The other end of 13 is connected to the input end of the evaporator 2, the outer surface of the evaporator 2 is in full contact with the molten salt 1, the outer surface of the condenser 7 is in full contact with the cold fluid 6, the condenser 7 is provided with a steam box 9 at the bottom, the evaporator 2 exchanges heat with the molten salt 1 to generate steam, the working fluid steam from the evaporator 2 first enters the steam box 9, rises under the action of the pressure difference and enters the condenser tube 702, exchanges heat with the cold fluid 5 and condenses into liquid, the working fluid liquid falls to the bottom of the steam box 9, the liquid contacts with the steam during the falling process to reduce the degree of supercooling, and maintains a temperature close to the saturation temperature of the working fluid, so that the molten salt evaporator does not freeze and block, and the molten salt heat exchanger is not limited by the temperature of the cold fluid.
[0024] Embodiment 3 of the utility model: A separated heat pipe molten salt heat exchanger, comprising an evaporator 2, which expands freely in a molten salt 1. A safety valve 3 is provided on the evaporator 2 to ensure the safety of the evaporator. The output end of the evaporator 2 is connected to one end of a steam pipe 5, and the other end of the steam pipe 5 is connected to a steam box 9. A condenser 7 is provided on the top of the steam box 9. The condenser 7 expands freely in a cold fluid 6. The bottom of the steam box 9 is connected to one end of a condensate underwater pipe 10, and the other end of the condensate underwater pipe 10 is connected to a separator 12. The output end of the separator 12 is connected to one end of a return pipe 13, and the other end of the return pipe 13 is connected to the input end of the evaporator 2. The outer surface of the evaporator 2 is in full contact with the molten salt 1, and the outer surface of the condenser 7 is in full contact with the molten salt 1. The cold fluid 6 is fully in contact, and the condenser 7 is provided with a steam box 9 at the bottom. The evaporator 2 exchanges heat with the molten salt 1 to generate steam. The working fluid steam from the evaporator 2 first enters the steam box 9, and rises under the action of the pressure difference to enter the condenser tube 702, and exchanges heat with the cold fluid 5 to condense into liquid. The working fluid liquid falls to the bottom of the steam box 9. The liquid contacts with the steam during the falling process to reduce the degree of supercooling, and maintains a temperature close to the saturation temperature of the working fluid, so that the molten salt evaporator does not freeze and block, and the molten salt heat exchanger is not limited by the temperature of the cold fluid; at the same time, a stop valve 4 is provided on the steam pipe 5, and the stop valve 4 is closed when the heat exchanger is shut down to prevent cold working fluid or cold air from entering the evaporator to cause the molten salt to solidify. An exhaust valve 8 is provided on the condenser 7, and the exhaust valve 8 is opened when the working fluid is injected, and the non-condensable gas is discharged to establish a vacuum when the heat exchanger is running.
[0025] Embodiment 4 of the utility model: A separated heat pipe molten salt heat exchanger, comprising an evaporator 2, which expands freely in a molten salt 1. A safety valve 3 is provided on the evaporator 2 to ensure the safety of the evaporator. The output end of the evaporator 2 is connected to one end of a steam pipe 5, and the other end of the steam pipe 5 is connected to a steam box 9. A condenser 7 is provided on the top of the steam box 9. The condenser 7 expands freely in a cold fluid 6. The bottom of the steam box 9 is connected to one end of a condensate underwater pipe 10, and the other end of the condensate underwater pipe 10 is connected to a separator 12. The output end of the separator 12 is connected to one end of a return pipe 13, and the other end of the return pipe 13 is connected to the input end of the evaporator 2. The outer surface of the evaporator 2 is in full contact with the molten salt 1, and the outer surface of the condenser 7 is in full contact with the molten salt 1. The cold fluid 6 is fully in contact, and the condenser 7 is provided with a steam box 9 at the bottom. The evaporator 2 exchanges heat with the molten salt 1 to generate steam. The working fluid steam from the evaporator 2 first enters the steam box 9, and rises under the action of the pressure difference to enter the condenser tube 702, and exchanges heat with the cold fluid 5 to condense into liquid. The working fluid liquid falls to the bottom of the steam box 9. The liquid contacts with the steam during the falling process to reduce the degree of supercooling, and maintains a temperature close to the saturation temperature of the working fluid, so that the molten salt evaporator does not freeze and block, and the molten salt heat exchanger is not limited by the temperature of the cold fluid; at the same time, a stop valve 4 is provided on the steam pipe 5, and the stop valve 4 is closed when the heat exchanger is shut down to prevent cold working fluid or cold air from entering the evaporator to cause the molten salt to solidify. An exhaust valve 8 is provided on the condenser 7, and the exhaust valve 8 is opened when the working fluid is injected, and the non-condensable gas is discharged to establish a vacuum when the heat exchanger is running. One end of the steam box 9 away from the steam pipe 5 is connected to one end of a balance pipe 11 , and the other end of the balance pipe 11 is connected to a separator 12 to balance the air pressure in the separator 12 . The steam in the separator 12 returns to the steam box through the balance pipe 11 .
[0026] Embodiment 5 of the utility model: A separated heat pipe molten salt heat exchanger, comprising an evaporator 2, which expands freely in a molten salt 1. A safety valve 3 is provided on the evaporator 2 to ensure the safety of the evaporator. The output end of the evaporator 2 is connected to one end of a steam pipe 5, and the other end of the steam pipe 5 is connected to a steam box 9. A condenser 7 is provided on the top of the steam box 9. The condenser 7 expands freely in a cold fluid 6. The bottom of the steam box 9 is connected to one end of a condensate underwater pipe 10, and the other end of the condensate underwater pipe 10 is connected to a separator 12. The output end of the separator 12 is connected to one end of a return pipe 13, and the other end of the return pipe 13 is connected to the input end of the evaporator 2. The outer surface of the evaporator 2 is in full contact with the molten salt 1, and the outer surface of the condenser 7 is in full contact with the molten salt 1. The cold fluid 6 is fully in contact, and the condenser 7 is provided with a steam box 9 at the bottom. The evaporator 2 exchanges heat with the molten salt 1 to generate steam. The working fluid steam from the evaporator 2 first enters the steam box 9, and rises under the action of the pressure difference to enter the condenser tube 702, and exchanges heat with the cold fluid 5 to condense into liquid. The working fluid liquid falls to the bottom of the steam box 9. The liquid contacts with the steam during the falling process to reduce the degree of supercooling, and maintains a temperature close to the saturation temperature of the working fluid, so that the molten salt evaporator does not freeze and block, and the molten salt heat exchanger is not limited by the temperature of the cold fluid; at the same time, a stop valve 4 is provided on the steam pipe 5, and the stop valve 4 is closed when the heat exchanger is shut down to prevent cold working fluid or cold air from entering the evaporator to cause the molten salt to solidify. An exhaust valve 8 is provided on the condenser 7, and the exhaust valve 8 is opened when the working fluid is injected, and the non-condensable gas is discharged to establish a vacuum when the heat exchanger is running. One end of the steam box 9 away from the steam pipe 5 is connected to one end of a balance pipe 11 , and the other end of the balance pipe 11 is connected to a separator 12 to balance the air pressure in the separator 12 . The steam in the separator 12 returns to the steam box through the balance pipe 11 .
[0027] If the position of the condenser 7 is lower than the evaporator 2, the return pipe 13 may be equipped with a condensate circulation pump 14 and a recirculation valve 15. The recirculation valve 15 and the condensate circulation pump 14 are installed in parallel on the return pipe 13, and the liquid in the separator 12 is returned to the evaporator 2 through the condensate circulation pump 14.
[0028] Embodiment 6 of the present utility model: A separated heat pipe molten salt heat exchanger, comprising an evaporator 2, which expands freely in a molten salt 1. A safety valve 3 is provided on the evaporator 2 to ensure the safety of the evaporator. The output end of the evaporator 2 is connected to one end of a steam pipe 5, and the other end of the steam pipe 5 is connected to a steam box 9. A condenser 7 is provided on the top of the steam box 9. The condenser 7 expands freely in a cold fluid 6. The bottom of the steam box 9 is connected to one end of a condensate underwater pipe 10, and the other end of the condensate underwater pipe 10 is connected to a separator 12. The output end of the separator 12 is connected to one end of a return pipe 13, and the other end of the return pipe 13 is connected to the input end of the evaporator 2. The outer surface of the evaporator 2 is in full contact with the molten salt 1, and the outer surface of the condenser 7 is in full contact with the molten salt 1. The cold fluid 6 is fully in contact, and the condenser 7 is provided with a steam box 9 at the bottom. The evaporator 2 exchanges heat with the molten salt 1 to generate steam. The working fluid steam from the evaporator 2 first enters the steam box 9, and rises under the action of the pressure difference to enter the condenser tube 702, and exchanges heat with the cold fluid 5 to condense into liquid. The working fluid liquid falls to the bottom of the steam box 9. The liquid contacts with the steam during the falling process to reduce the degree of supercooling, and maintains a temperature close to the saturation temperature of the working fluid, so that the molten salt evaporator does not freeze and block, and the molten salt heat exchanger is not limited by the temperature of the cold fluid; at the same time, a stop valve 4 is provided on the steam pipe 5, and the stop valve 4 is closed when the heat exchanger is shut down to prevent cold working fluid or cold air from entering the evaporator to cause the molten salt to solidify. An exhaust valve 8 is provided on the condenser 7, and the exhaust valve 8 is opened when the working fluid is injected, and the non-condensable gas is discharged to establish a vacuum when the heat exchanger is running. One end of the steam box 9 away from the steam pipe 5 is connected to one end of a balance pipe 11 , and the other end of the balance pipe 11 is connected to a separator 12 to balance the air pressure in the separator 12 . The steam in the separator 12 returns to the steam box through the balance pipe 11 .
[0029] The evaporator 2 includes an upper header 201 and a lower header 202, the upper header 201 is connected to the steam pipe 5, the lower header 202 is connected to the return pipe 13, a heat exchange tube 203 is arranged between the upper header 201 and the lower header 202, and the outer surface of the heat exchange tube 203 is provided with a heat exchange tube fin 204; the condenser 7 includes a connecting box 701, a condensing tube 702 is arranged between the connecting box 701 and the steam box 9, and the outer surface of the condensing tube 702 is provided with a condensing tube fin 703; the heat exchange tube fin 204 and the condensing tube fin 703 make the contact surface in the heat exchange process larger, thereby enhancing the heat exchange.
[0030] The working principle of an embodiment of the utility model is as follows: the evaporator 2 and the condenser 7 of the utility model can be installed on the heat absorbing and heat releasing pipes, and can be arranged in groups. Each group of inlets and outlets is provided with valves. Even if the molten salt corrodes the evaporation tube, the damaged tube group can be cut off without affecting the operation of the system; during operation, the condenser 7 is provided with a steam box 9 at the bottom, the evaporator 2 exchanges heat with the molten salt 1 to generate steam, the working fluid steam from the evaporator 2 first enters the steam box 9, rises under the action of the pressure difference and enters the condensation tube 702, exchanges heat with the cold fluid 5 and condenses into liquid, and the working fluid liquid falls into the bottom of the steam box 9. During the falling process, the liquid contacts with the steam to reduce the degree of supercooling, maintains a temperature close to the saturation temperature of the working fluid, so that the molten salt evaporator does not freeze and block, and the molten salt heat exchanger is not limited by the temperature of the cold fluid; the same heat exchanger can be arranged in the downstream and the upstream; the cold fluid can be arranged below the hot fluid, and the addition of a pump can realize the reflux of the working fluid in the evaporation section; and isothermal heat transfer is realized.
Claims
1. A separate heat pipe molten salt heat exchanger, characterized in that: The invention comprises an evaporator (2), wherein the output end of the evaporator (2) is connected to one end of a steam pipe (5), the other end of the steam pipe (5) is connected to a steam box (9), a condenser (7) is arranged on the top of the steam box (9), the bottom of the steam box (9) is connected to one end of a condensate underwater pipe (10), the other end of the condensate underwater pipe (10) is connected to a separator (12), the output end of the separator (12) is connected to one end of a return pipe (13), the other end of the return pipe (13) is connected to the input end of the evaporator (2).
2. A separate heat pipe molten salt heat exchanger according to claim 1, characterized in that: It also includes a molten salt (1) and a cold fluid (6), wherein the outer surface of the evaporator (2) is in full contact with the molten salt (1), and the outer surface of the condenser (7) is in full contact with the cold fluid (6).
3. A separate heat pipe molten salt heat exchanger according to claim 1, characterized in that: The evaporator (2) is provided with a safety valve (3).
4. A separate heat pipe molten salt heat exchanger according to claim 2, characterized in that: The steam pipe (5) is provided with a stop valve (4).
5. The separate heat pipe molten salt heat exchanger according to claim 1, characterized in that: The condenser (7) is provided with an exhaust valve (8).
6. The separate heat pipe molten salt heat exchanger according to claim 1, characterized in that: One end of the steam box (9) away from the steam pipe (5) is connected to one end of a balance pipe (11), and the other end of the balance pipe (11) is connected to a separator (12).
7. The separate heat pipe molten salt heat exchanger according to claim 1, characterized in that: The return water pipe (13) may be equipped with a condensate circulation pump (14).
8. A separate heat pipe molten salt heat exchanger according to claim 7, characterized in that: It also includes a recirculation valve (15), which is installed in parallel with the condensate circulation pump (14) on the return pipe (13).
9. The separate heat pipe molten salt heat exchanger according to claim 7, characterized in that: The evaporator (2) comprises an upper header (201) and a lower header (202), wherein the upper header (201) is connected to a steam pipe (5), and the lower header (202) is connected to a return water pipe (13). A heat exchange tube (203) is provided between the upper header (201) and the lower header (202), and a heat exchange tube fin (204) is provided on the outer surface of the heat exchange tube (203).
10. The separate heat pipe molten salt heat exchanger according to claim 7, characterized in that: The condenser (7) comprises a connection box (701), a condenser tube (702) is arranged between the connection box (701) and the steam box (9), and a condenser tube fin (703) is arranged on the outer surface of the condenser tube (702).