Public cooling system for converter stations in offshore flexible DC transmission projects
By designing a public cooling system for multi-stage heat exchangers in a converter station on the offshore flexible DC transmission engineering, the heat transfer of seawater and fresh water is used for cooling, the equipment operation problems caused by seawater corrosion are solved, and the system reliability and Stability and reduce maintenance and power consumption.
Patent Information
- Application Number
- CN202010819811.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-08-14
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2040-08-14
AI Technical Summary
Due to the corrosive and complex components of seawater, direct use of seawater cooling will lead to equipment suspension or damage, affecting operational reliability and stability.
A common cooling system including a seawater circulation module, a freshwater circulation module and a heating equipment circulation cooling module is designed. Heat exchange is performed through a multi-stage heat exchanger, and the heat transfer of seawater and freshwater is used for cooling, and it is used in the freshwater circulation module. Sodium hypochlorite prevents marine organisms from invasion and reduces the risk of corrosion.
It effectively reduces the corrosion risk of equipment, extends maintenance cycle, reduces material costs and power consumption, and improves the temperature stability and operating reliability of the system.
Smart Images
Figure CN111918534B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a common cooling system for a converter station of an offshore flexible direct current transmission project, and is applicable to the field of direct current transmission. Background Art
[0002] With the rapid development of the new energy industry, the scale of offshore wind power construction is expanding, and the problem of transmitting the generated electric energy to the corresponding power consumption area is faced. According to past experience, the traditional wind power transmission method generally adopts the high-voltage AC grid connection method, but this method is limited to small-scale, offshore wind farms. As offshore wind power development enters the deep sea and large-scale development, the high-voltage flexible direct current transmission method is more economical than the high-voltage AC transmission method, so the construction of offshore converter stations for conversion and boosting came into being.
[0003] During the operation of offshore converter stations, converter valves, connecting transformers and other electrical equipment will generate a large amount of heat (10,000 kW level). Timely and reliable cooling of various transmitting equipment is the basic prerequisite for the safe operation of offshore converter stations.
[0004] The offshore converter station is located in the open sea, where the temperature of seawater is relatively stable and inexhaustible. Considering seawater as a cooling water source according to local conditions has a very obvious cost advantage. However, due to the complex composition and strong corrosiveness of seawater, it is not suitable for direct cooling of various equipment in the converter station. If seawater is used to directly exchange heat with the cooling medium in the heating equipment, once leakage occurs, the high-conductivity seawater enters the low-conductivity internal cooling circulation system, which will seriously affect the normal operation of the equipment and even cause the equipment to stop or be damaged. Summary of the invention
[0005] The technical problem to be solved by the present invention is: in view of the above-mentioned problems, a common cooling system for a converter station of an offshore flexible DC transmission project is provided to improve the reliability and stability of the operation of the entire converter station.
[0006] The technical solution adopted by the present invention is: a public cooling system for a converter station of an offshore flexible direct current transmission project, characterized in that it includes a seawater circulation module, a fresh water circulation module and a heating equipment circulation cooling module, a plurality of heat exchangers I for heat exchange between the seawater circulation module and the fresh water circulation module are arranged between the seawater circulation module and the fresh water circulation module, and a plurality of heat exchangers II for heat exchange between the fresh water circulation module and the heating equipment circulation cooling module are arranged between the fresh water circulation module and the heating equipment circulation cooling module.
[0007] The seawater circulation module has a seawater pump group, the water intake of the seawater pump group is located below the sea level, the water outlet of the seawater pump group is connected to the cold side input end of the heat exchanger I through a seawater filter, and the cold side output end of the heat exchanger I is connected to the sea through a water outlet pipe.
[0008] The fresh water circulation module comprises a fresh water pipeline I connecting the hot side output end of the heat exchanger I and the cold side input end of the heat exchanger II, and a fresh water pipeline II connecting the cold side output end of the heat exchanger II and the hot side input end of the heat exchanger I, wherein a centrifugal pump group is installed on the fresh water pipeline I.
[0009] The fresh water pipeline I is connected with a fresh water replenishing and pressure stabilizing device.
[0010] It also includes an air conditioning condensing heat exchanger, which is connected to the seawater circulation module to use seawater as a cold source; the air conditioning condensing heat exchanger is connected to the heating equipment circulation cooling module to cool the heat emitted by the electrical equipment into the air as a heat source.
[0011] The seawater circulation module also includes a marine life prevention device.
[0012] The anti-marine life device adopts a sodium hypochlorite generator.
[0013] The beneficial effects of the present invention are: the heat transfer of seawater and fresh water is utilized through the seawater circulation module and the fresh water circulation module to effectively cool the various heating devices on the offshore platform. In the present invention, the area where seawater flows is located in the external cooling part, which only accounts for a small part of the entire cooling system, and fresh water accounts for a large proportion in the system. When the system uses fresh water to operate, the corrosion of pipes and valve accessories will be greatly reduced, the cycle requiring regular maintenance will increase significantly, the maintenance cost will be reduced, and the material requirements for pipes and accessories under fresh water operation conditions will be reduced, the range of options will be increased, and the material cost will be reduced. The temperature inside the system of the present invention is controlled by the number and frequency of pump group starts, which is independent of the seawater temperature, can maintain a stable temperature, help reduce mechanical wear, and save electricity. When the equipment temperature is high, the frequency and number of corresponding pump group starts will increase appropriately; when the equipment temperature is low, the frequency and number of corresponding pump group starts will be reduced to keep the overall system temperature stable within a certain range. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a structural schematic diagram of an embodiment.
[0015] In the figure: 1. Seawater pump group; 2. Seawater filter; 3. Heat exchanger I; 4. Air conditioning condensing heat exchanger; 5. Fresh water replenishment and pressure stabilizing device; 6. Centrifugal pump group; 7. Heat exchanger II; 701, valve cooling heat exchanger; 702, transformer heat exchanger; 8. Anti-marine life device. DETAILED DESCRIPTION
[0016] like Figure 1As shown, this embodiment is a common cooling system for a converter station of an offshore flexible DC transmission project, including a seawater circulation module, a fresh water circulation module and a heat generation equipment circulation cooling module, wherein a plurality of heat exchangers I are provided between the seawater circulation module and the fresh water circulation module, and a plurality of heat exchangers II are provided between the fresh water circulation module and the heat generation equipment circulation cooling module.
[0017] In this example, the seawater circulation module has a seawater pump group, a seawater filter and an anti-marine life device. The water intake of the seawater pump group is located a certain distance below the sea level. The water outlet of the seawater pump group is connected to the cold side input ends of the three heat exchangers I after passing through the seawater filter. The cold side output end of the heat exchanger I is connected to the sea through the outlet pipe.
[0018] In this embodiment, the anti-marine life device adopts a sodium hypochlorite generator. Part of the seawater treated by the seawater filter enters the anti-marine life device. The device generates sodium hypochlorite by electrolyzing seawater and transports it to the water intake of the seawater pump group to ensure that all pipe sections and components of the seawater circulation unit are not affected by marine life.
[0019] In this embodiment, the fresh water circulation module has a fresh water pipeline I and a fresh water pipeline II. The fresh water pipeline I is connected to the hot side output end of the heat exchanger I and the cold side input end of the heat exchanger II, and a centrifugal pump group is installed on the fresh water pipeline I; the fresh water pipeline II is connected to the cold side output end of the heat exchanger II and the hot side input end of the heat exchanger I.
[0020] In this example, a fresh water replenishment and pressure stabilization device is connected to the fresh water pipeline I. By replenishing fresh water and adjusting the pipeline pressure, the stability of the intermediate fresh water circulation unit is guaranteed, further ensuring the normal operation of the entire cooling system.
[0021] In this embodiment, the heat exchanger II includes a valve-cooled heat exchanger and a transformer heat exchanger. In this embodiment, the heat-generating equipment circulating cooling module includes a deionized water pipeline I connected to the hot side input end of the valve-cooled heat exchanger and a deionized water pipeline II connected to the hot side output end of the valve-cooled heat exchanger, as well as a transformer oil pipeline I connected to the hot side input end of the transformer heat exchanger and a transformer oil pipeline II connected to the hot side output end of the transformer heat exchanger.
[0022] This embodiment also includes an air conditioning condensing heat exchanger. Part of the seawater in the seawater circulation module that has been processed by the seawater filter enters the cold side input end of the air conditioning condensing heat exchanger, and the cold side output end of the air conditioning condensing heat exchanger is connected to the sea through the outlet pipe; the air conditioning condensing heat exchanger is connected to the heating equipment circulation cooling module. When the ambient temperature is high in summer, the air conditioning condensing heat exchanger uses seawater as a cold source and performs cooling through the air conditioning system; when the ambient temperature is low in winter, the air conditioning condensing heat exchanger uses the heat generated by the equipment as a heat source and performs heating through the air conditioning system.
[0023] The cooling method of this embodiment is as follows:
[0024] Deionized water and transformer oil undergo the first heat exchange with the cooled equipment to obtain high-temperature internal cooling water and high-temperature transformer oil;
[0025] The high-temperature internal cooling water and the high-temperature transformer oil respectively and simultaneously perform a second heat exchange with the low-temperature fresh water in the middle fresh water circulation module, and the low-temperature fresh water is converted into high-temperature fresh water;
[0026] The high-temperature fresh water undergoes a third heat exchange with the low-temperature seawater in the seawater circulation module to form high-temperature seawater, which is then discharged into the sea.
[0027] The above embodiments are only used to explain the inventive concept of the present invention, rather than to limit the protection of the rights of the present invention. Any non-substantial changes to the present invention using this concept shall fall within the protection scope of the present invention.
Claims
1. A common cooling system for a converter station of an offshore flexible DC transmission project, characterized in that: It comprises a seawater circulation module, a freshwater circulation module and a heat generating equipment circulation cooling module, wherein a plurality of heat exchangers I (3) for heat exchange between the seawater circulation module and the freshwater circulation module are provided, and a plurality of heat exchangers II (7) for heat exchange between the freshwater circulation module and the heat generating equipment circulation cooling module are provided; The seawater circulation module comprises a seawater pump group (1), the water inlet of the seawater pump group (1) is located below the sea level, the water outlet of the seawater pump group (1) is connected to the cold side input end of the heat exchanger I (3) through a seawater filter (2), and the cold side output end of the heat exchanger I (3) is connected to the sea through a water outlet pipe; The fresh water circulation module comprises a fresh water pipeline I connecting the hot side output end of the heat exchanger I (3) and the cold side input end of the heat exchanger II (7), and a fresh water pipeline II connecting the cold side output end of the heat exchanger II (7) and the hot side input end of the heat exchanger I (3), wherein a centrifugal pump group (6) is installed on the fresh water pipeline I; and a fresh water replenishment and pressure stabilization device (5) is connected to the fresh water pipeline I.
2. The public cooling system for a converter station of an offshore flexible DC transmission project according to claim 1 is characterized in that: It also includes an air conditioning condensing heat exchanger (4), the air conditioning condensing heat exchanger (4) being connected to the seawater circulation module to use the seawater as a cold source; the air conditioning condensing heat exchanger (4) being connected to the heating equipment circulation cooling module to cool the heat emitted by the electrical equipment into the air as a heat source.
3. The public cooling system for a converter station of an offshore flexible DC transmission project according to claim 1 is characterized in that: The seawater circulation module also includes a marine life prevention device (8).
4. The public cooling system for a converter station of an offshore flexible DC power transmission project according to claim 3 is characterized in that: The marine life prevention device (8) adopts a sodium hypochlorite generator.