Light-storage direct-flexible low-carbon cold supply system for public building

Abstract

The invention discloses a light-storage direct-flexible low-carbon cold supply system for a public building. The light-storage direct-flexible low-carbon cold supply system comprises a power distribution part and a centralized cold station part, the power distribution part comprises a direct current bus, an alternating current bus, a distributed photovoltaic system and a distributed power storage system; the centralized cold station part comprises a variable-frequency refrigerator, a variable-frequency cooling transmission and distribution side, a variable-frequency freezing transmission and distribution side and a variable-frequency cold storage transmission and distribution side; the centralized cooling station part can realize a refrigeration mode, a cold storage mode, a cold release mode, a simultaneous supply and storage mode and a simultaneous supply and release mode; according to the invention, a refrigeration mode, a cold storage mode, a cold discharge mode, a simultaneous supply and storage mode and a simultaneous supply and discharge mode are realized, high-power motor load direct-current power utilization is realized, a power distribution system structure and a variable-frequency load structure are simplified, an electric energy conversion link is reduced, the power distribution efficiency is improved, access of distributed clean power is facilitated, and the system has strong flexible adjustment capability and is suitable for popularization and application. The distributed photovoltaic power of the field can be efficiently consumed, a municipal power grid is assisted to consume remote clean power, and safe, economical and low-carbon cold supply is achieved.

Description

Technical Field

[0001] The invention relates to a photovoltaic, storage, direct and flexible cooling system, and in particular to a photovoltaic, storage, direct and flexible cooling system for public buildings. Background Art

[0002] Photovoltaic, energy storage, direct current and flexible (PEDF) is the abbreviation for the application of four technologies in the construction field: photovoltaic (Photovoltaic), energy storage (Energy storage), direct current (Direct current) and flexible interaction (Flexibility).

[0003] The proposal of a new type of building distribution system with solar energy storage and direct-flexible power supply not only provides a new development idea for the power sector to build a new power system with new energy as the main body, but also provides new impetus for the low-carbon transformation of the building sector. In the context of comprehensive electrification reform of energy-consuming terminals, on the basis of "saving energy, improving efficiency, and controlling total amount", providing buildings with zero-carbon electricity, zero-carbon cooling, and zero-carbon heat is the only way to further reduce the actual carbon emissions of energy consumption at the building terminal.

[0004] Public buildings have high energy consumption intensity and carbon emission intensity, and are the key areas of work for the construction sector. The air conditioning system is one of the main energy-consuming parts of a building, with a large proportion of energy consumption, high energy consumption intensity, and obvious fluctuation characteristics. The air conditioning system is the main contributor to the peak load of the power system during the cooling season. How to combine the photovoltaic storage direct-flexible technology with the centralized cooling system of public buildings, and efficiently utilize the distributed photovoltaic power of the site and assist the power grid in absorbing clean electricity from afar during the cooling season when photovoltaic resources are relatively sufficient, so as to achieve safe, efficient, economical, low-carbon or even zero-carbon cooling, is a very important and significant research topic. Summary of the invention

[0005] In order to solve the shortcomings of the above-mentioned technology, the present invention provides a solar-storage direct-flexible low-carbon cooling system for public buildings.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a solar-storage direct-flexible low-carbon cooling system for public buildings, including a power distribution part and a centralized cooling station part;

[0007] The power distribution part includes a DC busbar that supplies power to the centralized cooling station, an AC busbar connected to the DC busbar, a distributed photovoltaic system, and a distributed power storage system;

[0008] The centralized cooling station includes variable frequency chillers, variable frequency cooling transmission and distribution side, variable frequency refrigeration transmission and distribution side, and variable frequency cold storage transmission and distribution side, each of which is equipped with a DC inverter and connected to the DC bus.

[0009] The centralized cooling station part can realize cooling mode, cold storage mode, cooling release mode, simultaneous supply and storage mode and simultaneous supply and release mode.

[0010] Furthermore, a bidirectional AC / DC converter is provided between the DC bus and the AC bus, and the bidirectional AC / DC converter is implemented in a manner of completing rectification transformation and inversion transformation between the DC bus and the AC bus. One path of the AC bus supplies power to the AC load in the external building, and the other path of the AC bus is connected to the municipal power grid through a transformer.

[0011] Furthermore, the variable frequency chiller is implemented in a way of directly supplying cooling to the end of the building, so that the centralized cooling station can partially realize the cooling mode.

[0012] Furthermore, the variable frequency cooling transmission and distribution side acts as a heat exchange device for the variable frequency refrigerator to discharge the condensation heat of the variable frequency refrigerator to the low-temperature cold source.

[0013] Furthermore, when the centralized cold station part is a primary pump system, the variable frequency refrigeration distribution side includes a first chilled water pump equipment group, the first chilled water pump equipment group is connected to the variable frequency chiller and distributes the building terminal demand cold energy output by the variable frequency chiller to the heat exchange equipment, and the heat exchange equipment distributes the building terminal demand cold energy distributed from the previous process to the building terminal.

[0014] Furthermore, when the centralized cold station part is a secondary pump system, the variable frequency refrigeration distribution side includes a second chilled water pump equipment group and a third chilled water pump equipment group. The second chilled water pump equipment group is connected to the variable frequency chiller and the cooling capacity output by the variable frequency chiller is divided into two supply routes, thereby jointly realizing the same supply and storage mode.

[0015] Furthermore, the second chilled water pump equipment group supplies the required cooling capacity of the building terminal to the third chilled water pump equipment group, and the third chilled water pump equipment group then distributes the required cooling capacity of the building terminal delivered from the previous process to the building terminal through the heat exchange equipment connected thereto;

[0016] The second chilled water pump equipment group is connected to the cold storage water pump equipment group on the variable frequency cold storage distribution side. The cold storage water pump equipment group distributes the cold storage amount distributed from the previous process to the cold storage system, thereby realizing the cold storage mode.

[0017] Furthermore, the variable frequency cold storage transmission and distribution side includes a cold storage water pump equipment group and a cold discharge water pump equipment group;

[0018] The cold storage water pump equipment group is implemented in a manner of providing a power source for the cold storage cycle of the cold storage system;

[0019] The cooling water pump equipment group is implemented in a way that provides a power source for the cooling cycle of the cold storage system, and the cooling mode is realized by supplying cooling to the terminal of the building through the cold storage system.

[0020] Furthermore, the variable frequency chiller, variable frequency cooling distribution side, variable frequency refrigeration distribution side, and variable frequency cold storage distribution side are all AC loads and the DC inverters matching the four are DC / AC rectifier converters.

[0021] Further, the distributed photovoltaic system is connected to the DC bus through the photovoltaic converter;

[0022] The distributed power storage system is connected to the DC bus through an energy storage converter.

[0023] A low-carbon photovoltaic storage direct flexible cooling system for public buildings realizes cooling mode, cold storage mode, cooling release mode, co-supply and co-storage mode, and co-supply and co-release mode, realizes DC power consumption of high-power motor loads, simplifies the distribution system structure and variable frequency load structure, reduces power conversion links, improves distribution efficiency, and is more conducive to the access of distributed clean electricity. It also has strong flexible regulation capabilities, can efficiently absorb local distributed photovoltaic power, and assist the municipal power grid in absorbing distant clean electricity, thus realizing safe, economical, and low-carbon cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the present invention.

[0025] Figure 2 It is a schematic diagram of the transmission and distribution side of the variable frequency cooling of the present invention.

[0026] Figure 3 This is a schematic diagram of the distribution of Example 2 of the present invention.

[0027] Figure 4 This is a schematic diagram of the transmission and distribution of Example 3 of the present invention.

[0028] Figure 5 It is a schematic diagram of the cold storage system distribution of the present invention.

[0029] In the figure: 1. DC bus; 2. AC bus; 3. Bidirectional AC / DC converter; 4. Distributed photovoltaic system; 5. Photovoltaic converter; 6. Distributed power storage system; 7. Energy storage converter; 8. DC inverter; 9. Variable frequency chiller; 10. Variable frequency cooling transmission and distribution side; 11. Variable frequency refrigeration transmission and distribution side; 12. Variable frequency cold storage transmission and distribution side; 13. AC load; 14. Transformer; 15. Municipal power grid; 16. Centralized cold station part; 17. Low temperature cold source; 18. First chilled water pump equipment group; 19. Heat exchange equipment; 20. Building terminal; 21. Second chilled water pump equipment group; 22. Third chilled water pump equipment group; 23. Cold storage system; 24. Cold storage water pump equipment group; 25. Cooling water pump equipment group. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] This embodiment is about a solar-storage direct-flexible low-carbon cooling system for public buildings. Figure 1As shown, it includes a power distribution part and a centralized cooling station part 1; the power distribution part includes a DC bus 1 for supplying power to the centralized cooling station part 16, an AC bus 2 connected to the DC bus 1, a distributed photovoltaic system 4, and a distributed power storage system 6; Figure 1 As shown, the centralized cooling station part 16 includes a variable frequency chiller 9, a variable frequency cooling distribution side 10, a variable frequency refrigeration distribution side 11, and a variable frequency cold storage distribution side 12, each of which is respectively equipped with a DC inverter 8 and connected to the DC bus 1; the centralized cooling station part 16 can realize a cooling mode, a cold storage mode, a cold release mode, a same supply and storage mode, and a same supply and release mode.

[0033] Preferably, the variable frequency chiller 9, the variable frequency cooling distribution side 10, the variable frequency refrigeration distribution side 11, and the variable frequency cold storage distribution side 12 are all AC loads and the DC inverter 8 matching the four is a DC / AC rectifier converter. The DC inverter 8 can convert the smooth DC power provided by the DC bus 1 into variable frequency AC power, thereby driving the AC loads in the centralized cold station part 16, that is, the variable frequency chiller 9, the variable frequency cooling distribution side 10, the variable frequency refrigeration distribution side 11, and the variable frequency cold storage distribution side 12 and the equipment installed therein for variable frequency operation.

[0034] Preferably, the distributed photovoltaic system 4 is connected to the DC bus 1 through a photovoltaic converter 5. The distributed photovoltaic system 4 includes distributed photovoltaics on the roof of the building and distributed ground photovoltaics around the building. In order to make full use of space resources, the distributed photovoltaic system 4 can be laid horizontally; the distributed power storage system 6 is connected to the DC bus 1 through a storage converter 7.

[0035] On this basis, a bidirectional AC / DC converter 3 is provided between the DC bus 1 and the AC bus 2. The bidirectional AC / DC converter 3 is implemented in a manner of completing rectification transformation and inversion transformation between the DC bus 1 and the AC bus 2. One path of the AC bus 2 supplies power to the AC load 13 in the external building, and the other path of the AC bus 2 is connected to the municipal power grid 15 through a transformer 14.

[0036] The variable frequency chiller 9 is implemented in a manner of directly supplying cooling to the building terminal 20 , so that the centralized cooling station part 16 realizes the cooling mode, that is, the cooling mode is that the variable frequency chiller 9 only supplies cooling to the building terminal 20 .

[0037] like Figure 2 As shown, the variable frequency cooling transmission and distribution side 10 serves as a heat exchange device for the variable frequency chiller 9 to discharge the condensation heat of the variable frequency chiller 9 to a low temperature cold source 17. Preferably, the low temperature cold source 17 includes outdoor air, groundwater, seawater, and soil. Those skilled in the art can select the specific type of the low temperature cold source 17 according to actual conditions, and this is hereby explained.

[0038] Example 2

[0039] Based on Example 1, this example sets up the centralized cooling station 16, specifically as follows: Figure 3 As shown, the centralized cold station part 16 is a primary pump system, so that the variable frequency refrigeration distribution side 11 includes a first chilled water pump equipment group 18. In this embodiment, the first chilled water pump equipment group 18 is connected to the variable frequency chiller 9 and distributes the building terminal demand cooling capacity output by the variable frequency chiller 9 to the heat exchange equipment 19. The heat exchange equipment 19 distributes the building terminal demand cooling capacity distributed from the previous process to the building terminal 20.

[0040] Example 3

[0041] On the basis of Example 1, this embodiment sets up the centralized cold station part 16, and this embodiment is different from Example 2 in that:

[0042] like Figure 4 As shown, the centralized cold station part 16 is a secondary pump system, so that the variable frequency refrigeration distribution side 11 includes a second chilled water pump equipment group 21 and a third chilled water pump equipment group 22, wherein the second chilled water pump equipment group 21 is connected to the variable frequency chiller 9 and the cooling capacity output by the variable frequency chiller 9 is divided into two supply routes, thereby jointly realizing the same supply and storage mode.

[0043] Furthermore, the second chilled water pump equipment group 21 supplies the building terminal demand cooling capacity to the third chilled water pump equipment group 22, and the third chilled water pump equipment group 22 then distributes the building terminal demand cooling capacity delivered in the previous process to the building terminal 20 through the heat exchange equipment 19 connected thereto;

[0044] The second chilled water pump device group 21 is connected to the cold storage water pump device group 24 of the variable frequency cold storage distribution side 12 by another path. The cold storage water pump device group 24 distributes the cold storage amount distributed in the previous process to the cold storage system 23. Then, the single path realizes the cold storage mode. It can be understood that the cold storage mode is that the variable frequency chiller 9 only supplies cold to the cold storage system 23.

[0045] In summary, the two supply routes formed by the branch of the second chilled water pump equipment group 21 jointly realize the same supply and storage mode. It can be understood that the same supply and storage mode means that the variable frequency chiller 9 supplies cold to the cold storage system 23 and the building terminal 20.

[0046] In summary of the above embodiments, the variable frequency cold storage transmission and distribution side 12 includes a cold storage water pump equipment group 24 and a cooling water pump equipment group 25, wherein the cold storage water pump equipment group 24 is implemented in a manner of providing a power source for the cold storage cycle of the cold storage system 23, and the cooling water pump equipment group 25 is implemented in a manner of providing a power source for the cooling cycle of the cold storage system 23. The cooling mode is realized by supplying cooling to the building terminal 20 through the cold storage system 23. It can be understood that the cooling mode means that the cold storage system 23 supplies cooling to the building terminal 20.

[0047] In summary of the above embodiments, when the variable frequency chiller 9 and the cold storage system 23 simultaneously provide cooling for the building terminal 20, a simultaneous supply and release mode is achieved.

[0048] The present application discloses a low-carbon photovoltaic storage direct flexible cooling system for public buildings, which realizes cooling mode, cold storage mode, cooling release mode, co-supply and co-storage mode and co-supply and co-release mode, realizes direct current power consumption of high-power motor loads, simplifies the distribution system structure and variable frequency load structure, reduces power conversion links, improves distribution efficiency, is more conducive to the access of distributed clean electricity, and has strong flexible regulation capabilities, can efficiently absorb local distributed photovoltaic power, and assist the municipal power grid in absorbing distant clean electricity, to achieve safe, economical and low-carbon cooling.

[0049] The above implementation modes are not limitations of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the scope of the technical solution of the present invention also belong to the protection scope of the present invention.

Claims

1. A solar-storage direct-flexible low-carbon cooling system for public buildings, characterized by: It includes a power distribution part and a centralized cooling station part (16); The power distribution part comprises a DC bus (1) for supplying power to a centralized cooling station part (16), an AC bus (2) connected to the DC bus (1), a distributed photovoltaic system (4), and a distributed power storage system (6); The centralized cooling station part (16) comprises a variable frequency chiller (9) each equipped with a DC frequency converter (8) and connected to the DC bus (1), a variable frequency cooling transmission and distribution side (10), a variable frequency freezing transmission and distribution side (11), and a variable frequency cold storage transmission and distribution side (12); The centralized cold station part (16) can realize a cooling mode, a cold storage mode, a cold release mode, a co-supply and co-storage mode, and a co-supply and co-release mode.

2. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 1 is characterized by: A bidirectional AC / DC converter (3) is provided between the DC bus (1) and the AC bus (2), and the bidirectional AC / DC converter (3) is implemented in a manner of completing rectification conversion and inversion conversion between the DC bus (1) and the AC bus (2). One path of the AC bus (2) supplies power to an AC load (13) in an external building, and the other path of the AC bus (2) is connected to a municipal power grid (15) via a transformer (14).

3. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 1 is characterized by: The variable frequency chiller (9) is implemented in a manner of directly supplying cooling to the building terminal (20), thereby enabling the centralized cooling station part (16) to achieve a cooling mode.

4. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 1 is characterized by: The variable frequency cooling transmission and distribution side (10) serves as a heat exchange device for the variable frequency cold machine (9) to discharge the condensation heat of the variable frequency cold machine (9) to a low-temperature cold source (17).

5. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 1 is characterized by: When the centralized cold station part (16) is a primary pump system, the variable frequency refrigeration distribution side (11) includes a first chilled water pump equipment group (18), the first chilled water pump equipment group (18) is connected to the variable frequency chiller (9) and distributes the building terminal demand cold energy output by the variable frequency chiller (9) to the heat exchange equipment (19), and the heat exchange equipment (19) distributes the building terminal demand cold energy distributed in the previous process to the building terminal (20).

6. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 1 is characterized by: When the centralized cold station part (16) is a secondary pump system, the variable frequency refrigeration distribution side (11) includes a second chilled water pump equipment group (21) and a third chilled water pump equipment group (22). The second chilled water pump equipment group (21) is connected to the variable frequency chiller (9) and supplies the cooling capacity output by the variable frequency chiller (9) in two ways, thereby jointly realizing a same supply and same storage mode.

7. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 6 is characterized by: The second chilled water pump equipment group (21) supplies the cooling capacity required at the end of the building to the third chilled water pump equipment group (22), and the third chilled water pump equipment group (22) then distributes the cooling capacity required at the end of the building delivered in the previous process to the end of the building (20) through the heat exchange equipment (19) connected thereto; The second chilled water pump equipment group (21) is connected to the cold storage water pump equipment group (24) on the variable frequency cold storage distribution side (12) by another route. The cold storage water pump equipment group (24) distributes the cold storage amount distributed in the previous process to the cold storage system (23), thereby realizing the cold storage mode.

8. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 7 is characterized by: The variable frequency cold storage transmission and distribution side (12) comprises a cold storage water pump equipment group (24) and a cold discharge water pump equipment group (25); The cold storage water pump equipment group (24) is implemented in a manner of providing a power source for the cold storage cycle of the cold storage system (23); The cooling water pump equipment group (25) is implemented in a manner of providing a power source for the cooling cycle of the cold storage system (23), and the cooling mode is realized by supplying cooling to the building terminal (20) through the cold storage system (23).

9. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 1 is characterized by: The variable frequency chiller (9), the variable frequency cooling transmission and distribution side (10), the variable frequency refrigeration transmission and distribution side (11), and the variable frequency cold storage transmission and distribution side (12) are all AC loads, and the DC inverter (8) matched with the four is a DC / AC rectifier converter.

10. The solar-storage direct-flexible low-carbon cooling system for public buildings according to claim 1 is characterized by: The distributed photovoltaic system (4) is connected to the DC bus (1) via a photovoltaic converter (5); The distributed power storage system (6) is connected to the DC bus (1) via an energy storage converter (7).

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