A full-condition composite dehumidification system for main cables of suspension bridges based on waste heat recovery

Abstract

The present invention provides a full-operating-condition composite dehumidification system for the main cable of a suspension bridge based on waste heat recovery, including a heat pump drying system, a rotary dehumidification system, and a regeneration preheating system. The heat pump drying system cools and dries the air, significantly reducing the absolute moisture content of the air; the rotary dehumidification system deeply dehumidifies the air to achieve dry air with a lower dew point; the regeneration preheating system is used to increase the temperature of the regenerated air, including condenser preheating and heat pipe condensation end preheating. The heat for preheating the heat pipe condensation end comes from the recovery of high-temperature waste heat by the heat pipe evaporation end. The heat pipe evaporation end and the condensation end are connected through a gas pipe and a liquid pipe to form a circulation loop. The present invention realizes the efficient utilization of cold and heat and the effective recovery of waste heat. It can operate in three dehumidification modes, effectively cope with high temperature and high humidity, medium temperature and high humidity, and low temperature and high humidity working conditions, realize efficient dehumidification under all working conditions of the suspension bridge, significantly slow down the corrosion rate of the main cable steel structure, and improve the reliability and safety of the main cable protection.

Description

Technical Field

[0001] The invention relates to the technical field of dehumidification and anti-corrosion of main cables of suspension bridges, and in particular to a full-operating-condition composite dehumidification system for main cables of suspension bridges based on waste heat recovery. Background Art

[0002] The main cable is made of high-strength steel wires and is the main load-bearing component of the suspension bridge. It is very important to effectively protect the main cable from corrosion. The main cable dehumidification system reduces the relative humidity inside the main cable by producing dry air and passing it into the inside of the main cable, creating a dry environment that is not conducive to corrosion, and improving the durability and safety of the main cable.

[0003] Almost all the dehumidification equipment used in existing suspension bridges at home and abroad are rotary dehumidifiers. When the inlet air temperature rises, the dehumidification capacity of the rotary dehumidifier will be limited and cannot meet the humidity requirements of the main cable air supply. At the same time, the rotary dehumidifier relies on electric heating regeneration, which consumes a lot of energy and has poor operating economy.

[0004] Due to the particularity of the protection of the main cable of the suspension bridge, the dehumidification equipment used in this field should be able to operate continuously and be able to cope with the various temperature and humidity environments faced by the suspension bridge throughout the year. However, the dehumidification range and dehumidification capacity of a single dehumidification technology are limited, and the adaptability to working conditions is often poor. At present, the coupling of heat pumps and rotors has been studied in the field of air conditioning, but these research results cannot be directly applied to the field of bridge dehumidification and anti-corrosion. Therefore, how to couple a composite dehumidification system that matches the characteristics of the suspension bridge, how to effectively recycle waste heat according to the energy endowment of the suspension bridge to improve the dehumidification energy efficiency, and how to switch to a suitable dehumidification mode according to the changes in temperature and humidity of the suspension bridge have become technical problems that technicians in the field of main cable protection urgently need to solve. Summary of the invention

[0005] The purpose of the present invention is to address the defects of the prior art and provide a full-operating-condition composite dehumidification system for the main cable of a suspension bridge based on waste heat recovery, so as to solve the problems of poor dehumidification capacity, small operating condition adaptability range, and high dehumidification energy consumption of the original rotary dehumidification system of the suspension bridge in summer.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A full-condition composite dehumidification system for the main cable of a suspension bridge based on waste heat recovery, characterized in that it includes a heat pump drying system, a rotary dehumidification system, a treatment air duct and a regeneration air duct; the heat pump drying system includes an evaporator, a condenser, a compressor and an expansion valve, and the evaporator, the compressor, the condenser, the expansion valve and the evaporator are sequentially connected to form a circulation loop; the rotary dehumidification system includes a dehumidification rotary wheel, and the dehumidification rotary wheel is provided with a dehumidification zone and a regeneration zone; the treatment air duct includes a first one-way valve, a second one-way valve, a fifth one-way valve, a sixth one-way valve, a treatment fan, the second one-way valve, the evaporator, the sixth one-way valve, the dehumidification zone, the treatment fan The machines are connected in sequence, the first one-way valve is connected in parallel between the inlet of the second one-way valve and the outlet of the evaporator, the fifth one-way valve is connected in parallel between the inlet of the sixth one-way valve and the outlet of the dehumidification zone, the inlet of the second one-way valve is connected to the atmosphere outside the main cable, and the outlet of the treatment fan is connected to the inside of the main cable; the regeneration air duct includes a third one-way valve, a fourth one-way valve, a regeneration fan, and a seventh one-way valve, the third one-way valve, condenser, regeneration fan, seventh one-way valve, and regeneration zone are connected in sequence, the fourth one-way valve is connected in parallel between the inlet of the third one-way valve and the outlet of the condenser, and the inlet of the third one-way valve and the outlet of the regeneration zone are both connected to the atmosphere outside the main cable.

[0008] Furthermore, the process air duct also includes a Roots blower, the inlet of the Roots blower is connected to the process blower outlet, and the outlet of the Roots blower is connected to the inside of the main cable.

[0009] Furthermore, it also includes a regenerative preheating system, which includes a heat pipe circulation loop, an eighth one-way valve, a ninth one-way valve, and a tenth one-way valve. The heat pipe circulation loop includes a heat pipe condensing end, a liquid pipe, a heat pipe evaporating end, and a gas pipe that are sequentially connected to form a circulation loop. The eighth one-way valve and the heat pipe condensing end are connected in series, and the inlet of the eighth one-way valve and the outlet of the heat pipe condensing end are respectively connected in parallel to the inlet and outlet of the seventh one-way valve. The outlet of the Roots blower, the ninth one-way valve, and the heat pipe evaporating end are sequentially connected, and the tenth one-way valve is connected in parallel between the inlet of the ninth one-way valve and the outlet of the heat pipe evaporating end.

[0010] Furthermore, the rotary dehumidification system also includes an electric heater, which is arranged between the condensation end of the heat pipe and the regeneration zone.

[0011] Furthermore, it also includes an eleventh one-way valve, the inlet of the eleventh one-way valve is connected to the outlet of the regeneration fan, and the outlet of the eleventh one-way valve is connected to the atmosphere outside the main cable.

[0012] Furthermore, the area ratio of the dehumidification zone to the regeneration zone is 3:1.

[0013] Furthermore, the processed air pipeline also includes a first filter, the inlet of the first filter is connected to the atmosphere outside the main cable, and the outlet is connected to the inlet of the first one-way valve.

[0014] Furthermore, the regeneration air duct also includes a second filter, the inlet of the second filter is connected to the atmosphere outside the main cable, and the outlet is connected to the inlet of the third one-way valve.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention couples the two technologies of heat pump drying and rotary dehumidification, significantly improving the dehumidification capacity of the equipment, and has three dehumidification modes, which can effectively cope with high temperature and high humidity, medium temperature and high humidity, and low temperature and high humidity working conditions, and achieve efficient dehumidification under all working conditions of the suspension bridge, ensuring the safety and reliability of the main cable protection. 2. The present invention simultaneously utilizes the cooling capacity of the evaporator and the heat of the condenser, and uses heat pipes to recover the high-temperature waste heat after the Roots blower, realizing the efficient utilization of cold and heat and the effective recovery of waste heat, greatly improving the economy and energy saving of the system operation. 3. The heat pipe in the present invention is driven by gravity, without consuming additional energy, further improving the economy of waste heat recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0017] Among them: 1-first filter; 2-second filter; 3-evaporator; 4-condenser; 5-compressor; 6-expansion valve; 7-dehumidification wheel; 8-dehumidification zone; 9-regeneration zone; 10-heat pipe condensation end; 11-heat pipe evaporation end; 12-liquid pipe; 13-gas pipe; 14-processing fan; 15-regeneration fan; 16-Roots blower; 17-electric heater; 18 first one-way valve; 19 second one-way valve; 20-third one-way valve; 21-fourth one-way valve; 22-fifth one-way valve; 23-sixth one-way valve; 24-seventh one-way valve; 25-eighth one-way valve; 26-ninth one-way valve; 27-tenth one-way valve; 28-eleventh one-way valve. DETAILED DESCRIPTION

[0018] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0019] Figure 1 A specific embodiment of a full-operating-condition composite dehumidification system for a main cable of a suspension bridge based on waste heat recovery is shown, comprising a heat pump drying system, a rotary dehumidification system, a regeneration preheating system, a treatment air duct and a regeneration air duct.

[0020] The heat pump drying system includes an evaporator 3, a condenser 4, a compressor 5 and an expansion valve 6. The evaporator 3 is located in the treatment air pipeline, and the condenser 4 is located in the regeneration air pipeline. The rotary dehumidification system includes an electric heater 17 and a dehumidification rotary wheel 7. The dehumidification rotary wheel 7 includes a dehumidification area 8 and a regeneration area 9. The regeneration preheating system includes a heat pipe circulation loop, an eighth one-way valve 25, a ninth one-way valve 26, and a tenth one-way valve 27. The heat pipe circulation loop includes a heat pipe condensation end 10, a heat pipe evaporation end 11, a liquid pipe 12 and a gas pipe 13. The heat pipe condensation end 10 is connected to the heat pipe evaporation end 11 through the liquid pipe 12 and the gas pipe 13.

[0021] In the process air pipeline, the first filter 1, the second one-way valve 19, the evaporator 3, the sixth one-way valve 23, the dehumidification zone 8, the process fan 14, and the Roots blower 16 are connected in sequence. The first filter 1 is located at the pipeline inlet and is connected to the external atmosphere of the main cable. The first one-way valve 18 is connected in parallel between the inlet of the second one-way valve 19 and the outlet of the evaporator 3. The fifth one-way valve 22 is connected in parallel between the inlet of the sixth one-way valve 23 and the outlet of the dehumidification zone 8.

[0022] In the regeneration air pipeline, the second filter 2, the third one-way valve 20, the condenser 4, the regeneration fan 15, the seventh one-way valve 24, the electric heater 17, and the regeneration zone 9 are connected in sequence, the second filter 2 is located at the pipeline inlet and communicates with the atmosphere outside the main cable, and the fourth one-way valve 21 is connected in parallel between the inlet of the third one-way valve 20 and the outlet of the condenser 4. The inlet of the eleventh one-way valve 28 is connected to the outlet of the regeneration fan 15, and the outlet of the eleventh one-way valve 28 is connected to the atmosphere outside the main cable.

[0023] In the heat pump drying system, the evaporator 3, the compressor 5, the condenser 4, the expansion valve 6 and the evaporator 3 are sequentially connected to form a circulation loop.

[0024] In the rotary dehumidification system, the rotary regeneration zone 9 is connected to the atmosphere outside the main cable.

[0025] In the regeneration preheating system, the heat pipe condensation end 10 is located in the regeneration air duct, and the heat pipe evaporation end 11 is located in the treatment air duct. The eighth one-way valve 25 and the heat pipe condensation end 10 are connected in series, the inlet of the eighth one-way valve 25 and the outlet of the heat pipe condensation end 10 are respectively connected in parallel at the inlet and outlet of the seventh one-way valve 24, the outlet of the Roots blower 16, the ninth one-way valve 26, and the heat pipe evaporation end 11 are connected in sequence, and the tenth one-way valve 27 is connected in parallel between the inlet of the ninth one-way valve 26 and the outlet of the heat pipe evaporation end 11.

[0026] Preferably, in the rotary dehumidification system, the ratio of the area of ​​the dehumidification zone 8 to the area of ​​the regeneration zone 9 of the dehumidification wheel 7 is 3:1.

[0027] The first filter 1 is connected to the atmosphere outside the main cable, the second filter 2 is connected to the atmosphere outside the main cable, and the eleventh one-way valve 28 is connected to the atmosphere outside the main cable.

[0028] The working principle of the heat pump drying system in the above embodiment is as follows:

[0029] The circulation process of the refrigerant in the heat pump drying system: the refrigerant absorbs heat and evaporates into low-pressure refrigerant vapor in the evaporator 3, the compressor 5 compresses the low-pressure refrigerant vapor into high-pressure refrigerant vapor, the high-pressure refrigerant vapor enters the condenser 4 to release heat and condense into refrigerant liquid, the refrigerant liquid enters the evaporator 3 after throttling and reducing the pressure in the expansion valve 6 to complete the cycle.

[0030] The principle of heat pump drying: the evaporator 3 is used to cool the external air and reduce its temperature to the dew point temperature, thereby condensing the water vapor in the air. At this time, the absolute moisture content of the air is reduced, achieving the purpose of dehumidification.

[0031] The working principle of the rotary wheel dehumidification system in the above embodiment is as follows:

[0032] A large amount of desiccant is attached to the dehumidification wheel 7. During the dehumidification process, when the air passes through the dehumidification zone 8, the water vapor in the air is adsorbed by the desiccant, and the absolute moisture content of the air is reduced because the water vapor partial pressure in the air is greater than the water vapor partial pressure on the desiccant surface. During the regeneration process, the air is first heated by the electric heater 17. When the high-temperature air passes through the regeneration zone 9 of the wheel, the temperature of the desiccant in the regeneration zone rises, and the water vapor partial pressure on the desiccant surface is greater than the water vapor partial pressure in the air. The water vapor on the desiccant surface is desorbed and enters the air, thereby completing the regeneration process. When the rotary dehumidification system is working, the dehumidification wheel 7 rotates continuously, so that the dehumidification process and the regeneration process are carried out simultaneously.

[0033] The working principle of the regeneration preheating system in the above embodiment is as follows:

[0034] When the Roots blower 16 pressurizes the atmosphere sent from the outside and supplies air to the main cable, a large amount of heat is generated. After passing through the heat pipe circulation loop, the high-temperature waste heat behind the Roots blower 16 can be recovered through the evaporation and condensation of the medium in the loop, thereby realizing the efficient utilization of cold and heat and the effective recovery of waste heat, greatly improving the economy and energy saving of the system operation.

[0035] The full-operating-condition composite dehumidification system for the main cable of a suspension bridge based on waste heat recovery can adopt different dehumidification modes for high-temperature and high-humidity, medium-temperature and high-humidity, and low-temperature and high-humidity conditions, to achieve efficient dehumidification of the main cable of a suspension bridge under all operating conditions.

[0036] Dehumidification mode 1: In summer, the air temperature and humidity near the suspension bridge are very high, which belongs to high temperature and high humidity working conditions. At this time, it is necessary to use a composite dehumidification system of a heat pump drying system and a rotary dehumidification system. The specific operation is: open the second one-way valve 19, the third one-way valve 20, the sixth one-way valve 23, the eighth one-way valve 25 and the ninth one-way valve 26, and close the first one-way valve 18, the fourth one-way valve 21, the fifth one-way valve 22, the seventh one-way valve 24, the tenth one-way valve 27 and the eleventh one-way valve 28. At this time, the temperature and humidity of the external air drop to a certain extent after passing through the evaporator 3, and then the humidity of the air supply is further reduced after passing through the dehumidification zone 8 of the dehumidification rotary wheel 7.

[0037] Dehumidification mode 2: During the transition season, the air temperature near the suspension bridge is lower, but the humidity is very high, which belongs to the medium temperature and high humidity working condition. At this time, the heat pump drying system is used alone. The specific operation is: open the second check valve 19, the third check valve 20, the fifth check valve 22, the tenth check valve 27 and the eleventh check valve 28, and close the first check valve 18, the fourth check valve 21, the sixth check valve 23, the seventh check valve 24, the eighth check valve 25 and the ninth check valve 26.

[0038] Dehumidification mode 3: In winter, the air temperature near the suspension bridge is very low, but the humidity is very high, which belongs to the low temperature and high humidity working condition. At this time, the rotary dehumidification system is used alone. The specific operation is: open the first check valve 18, the fourth check valve 21, the sixth check valve 23, the eighth check valve 25 and the ninth check valve 26, and close the second check valve 19, the third check valve 20, the fifth check valve 22, the seventh check valve 24, the tenth check valve 27 and the eleventh check valve 28.

[0039] The above specific implementation methods are only for illustrating the technical concept and structural features of the present invention, and the purpose is to enable relevant persons familiar with this technology to implement it. However, the above content does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A full-condition composite dehumidification system for main cables of a suspension bridge based on waste heat recovery, characterized in that: The invention comprises a heat pump drying system, a rotary dehumidification system, a treatment air pipeline and a regeneration air pipeline; the heat pump drying system comprises an evaporator (3), a condenser (4), a compressor (5) and an expansion valve (6); the evaporator (3), the compressor (5), the condenser (4), the expansion valve (6) and the evaporator (3) are sequentially connected to form a circulation loop; the rotary dehumidification system comprises a dehumidification rotary wheel (7); the dehumidification rotary wheel (7) is provided with a dehumidification zone (8) and a regeneration zone (9); the treatment air pipeline comprises a first one-way valve (18), a second one-way valve (19), a fifth one-way valve (22), a sixth one-way valve (23) and a treatment air fan (14); the second one-way valve (19), the evaporator (3), the sixth one-way valve (23), the dehumidification zone (8) and the treatment air fan (14) are sequentially connected; the first one-way valve (18) and the regeneration zone (9) are sequentially connected. The fifth one-way valve (22) is connected between the inlet of the second one-way valve (19) and the outlet of the evaporator (3); the fifth one-way valve (22) is connected in parallel between the inlet of the sixth one-way valve (23) and the outlet of the dehumidification zone (8); the inlet of the second one-way valve (19) is in communication with the atmosphere outside the main cable; the outlet of the treatment fan (14) is in communication with the interior of the main cable; the regeneration air pipeline comprises a third one-way valve (20), a fourth one-way valve (21), a regeneration fan (15), and a seventh one-way valve (24); the third one-way valve (20), the condenser (4), the regeneration fan (15), the seventh one-way valve (24), and the regeneration zone (9) are connected in sequence; the fourth one-way valve (21) is connected in parallel between the inlet of the third one-way valve (20) and the outlet of the condenser (4); the inlet of the third one-way valve (20) and the outlet of the regeneration zone (9) are both in communication with the atmosphere outside the main cable; The process air pipeline further comprises a Roots blower (16), the inlet of the Roots blower (16) being connected to the outlet of the process air blower (14), and the outlet of the Roots blower (16) being in communication with the interior of the main cable; The invention also comprises a regenerative preheating system, the regenerative preheating system comprising a heat pipe circulation loop, an eighth one-way valve (25), a ninth one-way valve (26), and a tenth one-way valve (27); the heat pipe circulation loop comprises a heat pipe condensing end (10), a liquid pipe (12), a heat pipe evaporating end (11), and a gas pipe (13) which are sequentially connected to form a circulation loop; the eighth one-way valve (25) and the heat pipe condensing end (10) are connected in series; the inlet of the eighth one-way valve (25) and the outlet of the heat pipe condensing end (10) are respectively connected in parallel to the inlet and outlet of the seventh one-way valve (24); the outlet of the Roots blower (16), the ninth one-way valve (26), and the heat pipe evaporating end (11) are sequentially connected; and the tenth one-way valve (27) is connected in parallel between the inlet of the ninth one-way valve (26) and the outlet of the heat pipe evaporating end (11).

2. According to claim 1, a full-condition composite dehumidification system for main cables of a suspension bridge based on waste heat recovery is characterized in that: The rotary dehumidification system further comprises an electric heater (17), wherein the electric heater (17) is arranged between the heat pipe condensation end (10) and the regeneration zone (9).

3. According to claim 1, a full-condition composite dehumidification system for main cables of a suspension bridge based on waste heat recovery is characterized in that: It also includes an eleventh one-way valve (28), the inlet of the eleventh one-way valve (28) is connected to the outlet of the regeneration fan (15), and the outlet of the eleventh one-way valve (28) is connected to the atmosphere outside the main cable.

4. According to claim 1, a full-condition composite dehumidification system for main cables of a suspension bridge based on waste heat recovery is characterized in that: The area ratio of the dehumidification zone (8) to the regeneration zone (9) is 3:

1.

5. According to claim 1, a full-condition composite dehumidification system for main cables of a suspension bridge based on waste heat recovery is characterized in that: The treated air pipeline further comprises a first filter (1), wherein the inlet of the first filter (1) is connected to the atmosphere outside the main cable, and the outlet is connected to the inlet of the first one-way valve (18).

6. According to claim 1, a full-condition composite dehumidification system for main cables of a suspension bridge based on waste heat recovery is characterized in that: The regeneration air pipeline further comprises a second filter (2), the inlet of the second filter (2) being connected to the atmosphere outside the main cable, and the outlet of the second filter (2) being connected to the inlet of the third one-way valve (20).

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