Green power and heat storage coupled distributed multi-generation system and method

Abstract

The invention discloses a green power and heat storage coupled distributed multi-generation system and method. The device comprises a water treatment device, a buffer water supplementing tank, a circulating booster water pump, a heat storage type steam heat supply system, an absorption heat pump, a new energy power generation module, a municipal power distribution network, a gas turbine, a connecting pipeline, a steam user, a hot water user and a cold energy user. The system has the advantages that intermittent high-temperature flue gas waste heat and clean energy power generation are used for heat storage of the heat storage type steam heat supply system, the system is environmentally friendly, low in carbon and compact in heat storage size, part of steam produced by the heat storage type steam heat supply system serves as a driving heat source of the absorption heat pump, the steam obtained after heat exchange is recycled, and the heat storage effect is good. The residual steam is stably supplied, combined cascade supply of electricity, high-grade steam, low-grade heat supply and cold energy is achieved, the combined cooling heating and power utilization efficiency is high, and the economic advantage is obvious.

Description

Technical Field

[0001] The present invention relates to a green, high-efficiency, low-carbon emission energy storage type combined cooling, heating and power system and method, and in particular to a distributed multi-generation system coupling green electricity and heat storage. Background Art

[0002] With the continuous growth of global energy demand and increasingly severe environmental problems, gas-fired power generation has become an important means to replace coal-fired power plants. Improving gas utilization efficiency and reducing energy consumption have become key issues that need to be urgently addressed in the thermal power field. Gas-fired cogeneration can effectively improve gas utilization efficiency. As a highly efficient heat energy conversion device, steam-type lithium bromide heat pumps have received extensive attention in the fields of energy conservation and emission reduction, waste heat recovery, and industrial refrigeration in recent years. With its superior thermal effect and environmental performance, it has become an important technical path to solve these problems. At present, lithium bromide absorption heat pumps have been widely used in industrial waste heat recovery, central air-conditioning systems, building energy conservation, and regional heating.

[0003] However, steam-type lithium bromide heat pumps have the following problems: when the supply of heat sources such as flue gas waste heat is unstable or fluctuating, the operating efficiency and effect of the heat pump will be affected to a certain extent; and most absorption heat pump units use hot water storage tanks as the unit heat storage module, resulting in large installation space required for the system and great influence of heat load.

[0004] Therefore, making full use of the intermittent high-temperature waste heat resources of gas turbines, improving the energy utilization efficiency of lithium bromide heat pump systems, and reducing heat storage space have become urgent issues to be solved. Summary of the invention

[0005] The object of the present invention is to overcome the above problems and provide a distributed multi-generation system and method coupling green electricity and heat storage.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a distributed multi-generation system coupling green electricity and heat storage, which includes a water treatment device, a buffer water tank, a circulating booster water pump, a thermal storage steam heating system, an absorption heat pump, a new energy power generation module, a municipal distribution network, a steam main pipeline, a refrigeration steam bypass, a hot water supply pipeline, a cooling pipeline and a gas turbine;

[0008] The water inlet pipeline sequentially passes through the water treatment device, the buffer water replenishing tank, and the circulating booster water pump, and then is connected to the water replenishing pipe of the heat storage steam heating system. The steam outlet of the heat storage steam heating system is connected to the main steam pipeline and the refrigeration steam bypass. The main steam pipeline is used to transport steam to steam users. The refrigeration steam bypass is reconnected to the water replenishing pipe of the heat storage steam heating system after exchanging heat with the high-temperature generator of the absorption heat pump, forming a bypass cycle. The electric energy generated by the new energy power generation module and the gas turbine is connected to the municipal power distribution network, used to supply power to the heat storage steam heating system or supply power externally. The flue gas generated by gas turbine power generation is transported to the heat storage steam heating system for waste heat recovery;

[0009] The hot water pipeline is taken out of the absorption heat pump system after exchanging heat with the absorber and condenser inside the absorption heat pump system, and is used to supply hot water to hot water users. The cooling pipeline is taken out of the absorption heat pump system after exchanging heat with the evaporator inside the absorption heat pump system, and is used to provide cold energy to cold energy users.

[0010] Preferably, the heat storage steam heating system is composed of four parts: a heat storage preheater, a heat storage steam generator, a steam-water separator, and a heat storage superheater, which are connected in series. The steam-water mixture of the heat storage steam generator enters the steam-water separator to be separated into saturated water and saturated steam. Among them, the saturated water flows back to the heat storage preheater, and the saturated steam is heated to superheated steam by the heat storage superheater and then output from the steam outlet; among them, the heat storage preheater and the heat storage steam generator are both dual heat source components, which can use the electric power provided by the municipal power distribution network for electric heat storage, and can also use the high-temperature waste heat flue gas generated by gas turbine power generation to heat the heat storage body inside, while the heat storage superheater electrically heats the heat storage body inside by the electric power provided by the municipal power distribution network.

[0011] Preferably, the electric power provided by the municipal power distribution network to the heat storage steam heating system comes from the clean energy electric power generated by the new energy power generation module, or the valley electricity directly provided by the municipal power distribution network.

[0012] Preferably, the heat storage preheater and the heat storage steam generator preferentially use the high-temperature waste heat flue gas generated by gas turbine power generation to heat the heat storage body inside. When the waste heat resources do not meet the minimum heating load, electric heating is used with the electric power provided by the municipal power distribution network to make up for the gap load.

[0013] Preferably, when the municipal power distribution network supplies power to the heat storage steam heating system, it preferentially uses the clean energy electric power generated by the new energy power generation module. When the clean energy electric power generated by the new energy power generation module is insufficient, hybrid power supply is carried out by combining clean energy electric power with the commercial power provided by the municipal power distribution network.

[0014] Preferably, the heat storage preheater, the heat storage steam generator, and the heat storage superheater are all internally heat-stored by a solid heat storage body. The material of the solid heat storage body is a solid sensible heat storage material or a composite heat storage material doped with a phase change material based on a solid sensible heat material, and its maximum heat storage temperature is not lower than 400 °C.

[0015] Preferably, the absorption heat pump system includes a high-temperature generator, a condenser, a heat exchanger, an absorber, and an evaporator. Among them, the high-temperature generator, the condenser, the evaporator, and the absorber are connected in sequence to form a circulation loop, and two working fluids transported bidirectionally between the high-temperature generator and the absorber exchange heat through the heat exchanger. Heat exchange is formed between the absorber and the condenser and the hot water supply pipeline.

[0016] Preferably, the new energy power generation module includes at least one of a photovoltaic power generation module and a small wind power generation module.

[0017] Preferably, the gas turbine adopts a distributed gas turbine.

[0018] In a second aspect, the present invention provides a combined cooling, heating, and power supply method for a distributed polygeneration system that utilizes the above-mentioned combined green power and heat storage in the first aspect. The specific method is as follows:

[0019] When the electricity load of the power grid is in the valley electricity state, the clean energy power generated by the new energy power generation module is directly used through the municipal power distribution network to heat the heat storage bodies inside the heat storage preheater, the heat storage steam generator, and the heat storage superheater in the heat storage steam heating system, realizing the direct consumption of clean energy power. When the power generation power of the new energy power generation module is not sufficient to fill the heat storage steam heating system, the valley electricity provided by the municipal power distribution network is further used for electric heat storage of the heat storage steam heating system. When the electricity load of the power grid is in the valley electricity state, the heat storage steam heating system is always kept for heat storage under the maximum heating power load until the heat storage system is full;

[0020] When the electricity load of the power grid is at peak power, the electricity generated by the new energy power generation module is supplied to the outside through the municipal power distribution network. And when the gas power generation price is lower than the peak power price of the power distribution network, the gas turbine is controlled to be in the working state, and the electricity generated by the gas turbine is supplied to the outside through the municipal power distribution network to achieve the purpose of peak shaving. The high-temperature flue gas waste heat generated by the gas turbine is used to heat the heat storage preheater and the heat storage steam generator in the regenerative steam heating system; when there is a heating load in the regenerative steam heating system at this time and the stored heat is not enough to meet the heating demand, the regenerative steam heating system is controlled to be heated with the lowest heating load demand, and the high-temperature flue gas waste heat generated by the gas turbine is preferentially used for heat charging. If the waste heat resources cannot meet the lowest heating load demand of the regenerative steam heating system, the electricity provided by the municipal power distribution network needs to be further used to make up the load gap, and its electricity comes from the clean energy electricity generated by the new energy power generation module or the direct power supply of the municipal power distribution network;

[0021] When steam and cold load need to be supplied to the outside, the water in the buffer water replenishing tank is boosted by the circulating booster pump and then flows into the regenerative steam heating system for heat exchange to generate superheated steam. One way of the superheated steam is directly supplied to the steam users through the main steam pipeline, and the other way of the superheated steam is input into the high-temperature generator of the absorption heat pump as the driving heat source for the heat pump cycle; on the one hand, the make-up water is heated in two stages through the absorber and the condenser through the hot water supply pipeline to provide low-grade domestic hot water and heating for the hot water users. On the other hand, the internal working medium is cooled through the evaporator heat exchange through the cold supply pipeline to provide cold energy for the cold energy users.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] (1) The present invention uses a high-temperature solid heat storage device to absorb the intermittent waste heat of the distributed gas turbine. The energy density is higher than that of the heat storage water tank, effectively reducing the heat storage space of the system and improving the utilization efficiency of the flue gas waste heat;

[0024] (2) The method of using high-temperature solid heat storage solves the source of the distributed high-temperature steam heat source of the lithium bromide heat pump. The intermittent high-temperature flue gas waste heat generated by the distributed gas turbine is preferentially used to efficiently and economically heat the heat storage body of the preheater and the heat storage body of the steam generator. The heat storage body of the superheater is preferentially heated by clean energy electricity and valley electricity. Through solid heat storage, the high-temperature flue gas waste heat with heat determined by electricity is converted into a stable steam load output, and the demand for multi-grade heat source combined supply is realized;

[0025] (3) The present invention effectively improves the energy efficiency of the heating system by fully recovering the high-temperature heat source waste heat of the lithium bromide heat pump, saves the production cost of life, and has good economic benefits. Description of the Drawings

[0026] Figure 1 It is a distributed poly-generation system that couples green electricity and thermal energy storage;

[0027] Figure 2 It is a schematic diagram of a heat storage steam generation system.

[0028] In the figure: water treatment device 1, buffer makeup water tank 2, circulating booster pump 3, heat storage steam heating system 4, absorption heat pump 5, new energy power generation module 6, municipal power distribution network 7, main steam pipeline 8, refrigeration steam bypass 9, hot water supply pipeline 10, cooling pipeline 11, steam user 12, hot water user 13, cold energy user 14 and gas turbine 15.

[0029] The absorption heat pump system 5 includes a high-temperature generator 51, a condenser 52, a heat exchanger 53, an absorber 54, and an evaporator 55.

[0030] The heat storage steam heating system 4 mainly includes a heat storage preheater 41, a heat storage steam generator 42, a steam-water separator 43, and a heat storage superheater 44. Specific embodiments

[0031] The present invention will be further described and explained below in conjunction with the accompanying drawings and specific embodiments.

[0032] In the description of the present invention, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, that is, there is an intermediate element. On the contrary, when an element is referred to as being "directly" connected to another element, there is no intermediate element.

[0033] As Figure 1 shown, the present invention provides a distributed poly-generation system that couples green electricity and thermal energy storage. The system includes a water treatment device 1, a buffer makeup water tank 2, a circulating booster pump 3, a heat storage steam heating system 4, an absorption heat pump 5, a new energy power generation module 6, a municipal power distribution network 7, a main steam pipeline 8, a refrigeration steam bypass 9, a hot water supply pipeline 10, a cooling pipeline 11, a steam user 12, a hot water user 13, a cold energy user 14, and a gas turbine 15.

[0034] A water treatment device 1, a buffer make-up water tank 2, and a circulating booster pump 3 are connected in sequence through a water inlet pipeline. The water treatment device 1 is used to perform necessary pretreatment on the original water supply. The specific form of the water treatment device 1 can be determined according to the water quality and the treatment requirements of the subsequent regenerative steam heating system 4 for make-up water. The water treated by the water treatment device 1 is stored in the buffer make-up water tank 2. The circulating booster pump 3 is used to boost the water in the buffer make-up water tank 2 and send it through a make-up water pipe into the regenerative steam heating system 4 to prepare the steam required by the steam user 12. The steam generated in the regenerative steam heating system 4 is discharged from the steam outlet. The steam of the regenerative steam heating system 4 is connected to the main steam pipeline 8. The end of the main steam pipeline 8 is connected to the steam user 12 to supply steam to the steam user 12. A refrigeration steam bypass 9 is provided at the inlet of the main steam pipeline 8. The steam output from the steam outlet of the regenerative steam heating system 4 can also be input into the refrigeration steam bypass 9 according to requirements to provide the heat required for the heat pump cycle for the absorption heat pump 5.

[0035] The absorption heat pump 5 adopted in the present invention belongs to the prior art. Its composition mainly includes a high-temperature generator 51, a condenser 52, a heat exchanger 53, an absorber 54, and an evaporator 55. Among them, the high-temperature generator 51, the condenser 52, the evaporator 55, and the absorber 54 are connected in sequence to form a circulation loop. And the two working fluids transported bidirectionally between the high-temperature generator 51 and the absorber 54 exchange heat through the heat exchanger 53. Heat exchange is formed between the absorber 54 and the condenser 52 and the hot water supply pipeline 10. Such an absorption heat pump 5 can be realized by using a lithium bromide absorption heat pump or an absorption heat pump with other working fluids. Taking the lithium bromide absorption heat pump as an example, the working principles inside the high-temperature generator 51, the condenser 52, the heat exchanger 53, the absorber 54, and the evaporator 55 are as follows:

[0036] In the high-temperature generator 51, using the high-temperature steam input from the outside as a heat source, the dilute lithium bromide solution in the high-temperature generator 51 is heated. After the dilute lithium bromide solution is heated, the water in it evaporates to form high-temperature and high-pressure water vapor. At the same time, the concentration of the lithium bromide solution increases and becomes a concentrated lithium bromide solution.

[0037] In the condenser 52, the high-temperature and high-pressure water vapor coming out of the high-temperature generator 51 enters the condenser 52, and the water vapor is cooled and condensed into liquid water. The heat released during the condensation process can be used to heat the low-temperature make-up water in the subsequent hot water supply pipeline 10.

[0038] In the heat exchanger 53, there are two working fluids transported bidirectionally between the high-temperature generator 51 and the absorber 54. One is the concentrated lithium bromide solution flowing from the high-temperature generator 51 to the absorber 54, and the other is the dilute lithium bromide solution flowing from the absorber 54 to the high-temperature generator 51. These two working fluids exchange heat in the heat exchanger 53, and the concentrated solution preheats the dilute solution, thereby recovering energy and improving the system efficiency.

[0039] In the evaporator 55, the liquid water absorbs the heat of the surrounding environment or the working fluid in the cooling pipeline 11 and evaporates into low-temperature and low-pressure water vapor.

[0040] In the absorber 54, the low-temperature and low-pressure water vapor coming out of the evaporator 55 enters the absorber 54, and the water vapor is absorbed by the concentrated lithium bromide solution to form a dilute lithium bromide solution. The heat released during the absorption process is first used to heat the low-temperature make-up water in the subsequent hot water supply pipeline 10, and the remaining part is transferred to the dilute lithium bromide solution about to enter the high-temperature generator 51 through the heat exchanger 53.

[0041] Thus, the lithium bromide solution and water will continuously circulate in the entire absorption heat pump 5 cycle loop to achieve the corresponding heat exchange function.

[0042] The input position of the external heat in the absorption heat pump 5 is the high-temperature generator 51. Therefore, the refrigeration steam bypass 9 needs to enter the absorption heat pump 5 to form a heat exchange contact with the high-temperature generator 51. The high-temperature steam in the refrigeration steam bypass 9 is reconnected to the make-up water pipe of the regenerative steam heating system 4 after heat exchange with the high-temperature generator 51 of the absorption heat pump 5, forming a bypass cycle.

[0043] In addition, the distributed poly-generation system of the present invention also has a new energy power generation module 6 and a gas turbine 15. The electric energy generated by the new energy power generation module 6 and the gas turbine 15 are both connected to the municipal power distribution network 7, used to supply power to the regenerative steam heating system 4 or directly supply power to the outside as municipal power. The high-temperature flue gas generated by the gas turbine 15 during power generation can be transported to the regenerative steam heating system 4 for waste heat recovery.

[0044] The gas turbine 15 in the present invention can be a distributed gas turbine to meet the usage scenario requirements of the present invention. The new energy power generation module 6 includes at least one of a photovoltaic power generation module and a small wind power generation module. The gas turbine 15 and the new energy power generation module 6 can be one or more, and the specific quantity is not limited.

[0045] In addition, the hot water supply pipeline 10 is connected out of the absorption heat pump system 5 after heat exchange with the absorber 54 and the condenser 52 inside the absorption heat pump system 5, used to supply hot water to the hot water user 13. The cooling pipeline 11 is connected out of the absorption heat pump system 5 after heat exchange with the evaporator 55 inside the absorption heat pump system 5, used to provide cold energy to the cold energy user 14.

[0046] It should be noted that the working fluid inside the cooling pipeline 11 can be water, or other gaseous or liquid working fluids that need to be cooled, depending on the specific requirements of the cold energy user 14, and there is no limit to this.

[0047] In addition, in the embodiments of the present invention, a regenerative steam heating system 4 applicable to the system of the present invention is provided. As Figure 2 shown, the regenerative steam heating system 4 is connected in series by four parts: a regenerative preheater 41, a regenerative steam generator 42, a steam-water separator 43, and a regenerative superheater 44. The above-mentioned regenerative preheater 41, regenerative steam generator 42, and regenerative superheater 44 all adopt regenerative devices, and the inside of each can be regenerated by a solid regenerator. The material of the solid regenerator is a solid sensible heat storage material, or a composite heat storage material based on a solid sensible heat material doped with a phase change material can also be selected. In order to meet the use requirements, its maximum heat storage temperature is not lower than 400°C. In this regenerative steam heating system 4, the internal operation mode is as follows: the steam-water mixture of the regenerative steam generator 42 enters the steam-water separator 43 to be separated into saturated water and saturated steam. The saturated water flows back to the regenerative preheater 41, and the saturated steam is heated to superheated steam after passing through the regenerative superheater 44 and then output from the steam outlet of the regenerative steam heating system 4, and enters the subsequent main steam pipeline 8 or the refrigeration steam bypass 9 as required. Since there are two heat sources, namely electric heating and high-temperature waste heat flue gas heating, in the present invention, both the regenerative preheater 41 and the regenerative steam generator 42 are dual-heat-source components. Electric regenerative heat storage can be carried out using the electric power provided by the municipal power distribution network 7, or the high-temperature waste heat flue gas generated by the gas turbine 15 for power generation can be used to heat the internal regenerator. Which heat source to use specifically can be selected according to the actual economic situation. And the regenerative superheater 43 has a relatively high requirement for the heat quality s, so the internal regenerator can be electrically heated by the electric power provided by the municipal power distribution network 7. However, since there is a new energy power generation module 6 in the present invention, and the clean energy power generated by the new energy power generation module 6 is also connected to the municipal power distribution network 7, the electric power provided by the municipal power distribution network 7 to the regenerative steam heating system 4 can be the clean energy power generated by the new energy power generation module 6, or the valley electricity directly provided by the municipal power distribution network 7.

[0048] Since the regenerative steam heating system 4 of the present invention can use the above-mentioned various energy sources for regenerative heat storage, different energy source usage priorities need to be set in different scenarios. For the regenerative preheater 41 and the regenerative steam generator 42, they can utilize the high-temperature waste heat resources to accumulate a certain amount of heat. Therefore, both of them should preferentially use the high-temperature waste heat flue gas generated by the gas turbine 15 for power generation to heat the internal regenerator. When the waste heat resources do not meet the minimum heating load, the electric power provided by the municipal power distribution network 7 is used for electric heating to make up for the gap load.

[0049] In addition, if the municipal power distribution network 7 needs to provide electric power to the regenerative steam heating system 4, the clean energy power generated by the new energy power generation module 6 is preferentially used. When the clean energy power generated by the new energy power generation module 6 is insufficient, a hybrid power supply is carried out by combining the clean energy power with the commercial power provided by the municipal power distribution network 7.

[0050] In addition, in principle, whether the distributed gas turbine 15 is enabled should be determined according to whether the gas power generation price is lower than the current electricity price of the distribution network. Generally speaking, when the gas power generation price is lower than the peak electricity price of the distribution network, the distributed gas turbine 15 can be controlled to be enabled, and the electricity generated by the distributed gas turbine 15 is supplied to the outside through the municipal distribution network 7 to achieve the purpose of peak shaving. At the same time, the waste heat of the high-temperature flue gas generated by it can be sent to the heat storage preheater 41 and the heat storage steam generator 42 for storage. However, the waste heat of the high-temperature flue gas of the gas turbine 15 is often intermittent and unstable. Therefore, when it cannot meet the heating requirements of the heat storage body, electric heating still needs to be introduced.

[0051] Based on the above Figure 1 distributed poly-generation system coupling green electricity and heat storage shown, a combined cooling, heating and power supply method based on this system is further provided, which includes a variety of different working modes, and is described as follows:

[0052] When the electricity load of the power grid is in the valley electricity state, the clean energy electricity generated by the new energy power generation module 6 is directly used through the municipal distribution network 7 to heat the heat storage bodies inside the heat storage preheater 41, the heat storage steam generator 42 and the heat storage superheater 44 of the heat storage steam heating system 4, so as to directly consume the clean energy electricity; when the power generation power of the new energy power generation module 6 is not enough to fill the heat storage steam heating system 4, the heat storage steam heating system 4 is further electrically heated by the valley electricity provided by the municipal distribution network 7 to consume part of the valley electricity load. Moreover, in order to fully consume the valley electricity and reduce the operation cost of the system, when the electricity load of the power grid is in the valley electricity state, the heat storage steam heating system 4 can always be maintained to store heat at the maximum heating power load until the heat storage system is full.

[0053] When the power consumption load of the power grid is at peak power, the power generated by the new energy power generation module 6 is supplied to the outside through the municipal power distribution network 7, and is no longer all supplied to the regenerative steam heating system 4; moreover, when the gas power generation price is lower than the peak power price of the power distribution network, it is also necessary to control the distributed gas turbine 15 to be in a working state. The power generated by the distributed gas turbine 15 is supplied to the outside through the municipal power distribution network 7 to achieve the purpose of peak shaving, and the high-temperature flue gas waste heat generated by the distributed gas turbine 15 is used to heat the regenerative preheater 41 and the regenerative steam generator 42 in the regenerative steam heating system 4; when there is a heating load in the regenerative steam heating system 4 at this time and the stored heat is insufficient to meet the heating demand, considering economy, control the regenerative steam heating system 4 to be heated only with the lowest heating load demand, and preferentially use the high-temperature flue gas waste heat generated by the distributed gas turbine 15 for heat charging. If the waste heat resources cannot meet the lowest heating load demand of the regenerative steam heating system 4, it is necessary to further use the power provided by the municipal power distribution network 7 to make up the load gap, and its power comes from the clean energy power generated by the new energy power generation module 6 or the direct power supply of the municipal power distribution network 7. Moreover, considering the power cost and economy, if it is necessary to use the power provided by the municipal power distribution network 7 to make up the load gap, preferentially use the clean energy power generated by the new energy power generation module 6, and use the municipal power distribution network 7 for power supply when the clean energy power generated by the new energy power generation module 6 cannot meet the demand.

[0054] When it is necessary to supply steam and cold load to the outside, the water in the buffer water replenishment tank 2 is boosted by the circulating booster pump 3 and then flows into the regenerative steam heating system 4 for heat exchange to generate superheated steam. One way of the superheated steam is directly supplied to the steam user 12 through the main steam pipeline 8, and the other way of the superheated steam is input into the high-temperature generator 51 of the absorption heat pump 5 as the driving heat source for the heat pump cycle; after the internal heat pump cycle of the absorption heat pump 5, heat and cold are generated. On the one hand, the makeup water is heated in two stages through the absorber 54 and the condenser 52 through the hot water supply pipeline 10, and low-grade domestic hot water and heating are provided to the hot water user 13. On the other hand, the internal working medium is cooled through the evaporator 55 through the cold supply pipeline 11 and then cold energy is provided to the cold energy user 14.

[0055] It can be seen that the present invention forms a system of cascaded supply of electricity-steam-hot water / heating-cooling. When there are heating and cooling loads in the system, intermittent high-temperature flue gas waste heat can be preferentially used. If electricity is needed, new energy electricity is preferred first, and grid power is introduced only when the electricity is insufficient. If there is surplus electricity generated by new energy power generation, it can be grid-connected for power supply in the peak power state, and can be used for heating the heat storage body in the valley power state.

[0056] In summary, the present invention can store heat in a regenerative steam heating system by using the waste heat of intermittent high-temperature flue gas and clean energy power generation, which is green and low-carbon, and has a compact heat storage volume. Part of the steam produced by the regenerative steam heating system is used as the driving heat source of an absorption heat pump, and the steam after heat exchange is recycled, while the remaining steam is stably supplied, realizing the combined cascade supply of electricity, high-grade steam, low-grade heating, and cold energy. The combined heat and power generation utilization efficiency is high, and the economic advantage is obvious.

[0057] The embodiments described above are only some preferred implementation solutions of the present invention, but are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by means of equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A distributed multi-generation system coupling green electricity and heat storage, characterized in that It comprises a water treatment device (1), a buffer water supply tank (2), a circulating booster water pump (3), a thermal storage steam heating system (4), an absorption heat pump (5), a new energy power generation module (6), a municipal distribution network (7), a steam main pipeline (8), a refrigeration steam bypass (9), a hot water supply pipeline (10), a cooling pipeline (11) and a gas turbine (15); The water inlet pipeline passes through the water treatment device (1), the buffer water supply tank (2), and the circulating booster water pump (3) in sequence and is then connected to the water supply pipe of the thermal storage steam heating system (4). The steam outlet of the thermal storage steam heating system (4) is connected to the steam main pipeline (8) and the refrigeration steam bypass (9). The steam main pipeline (8) is used to transport steam to the steam user (12). The refrigeration steam bypass (9) is reconnected to the water supply pipe of the thermal storage steam heating system (4) after heat exchange with the high-temperature generator (51) of the absorption heat pump (5), thereby forming a bypass cycle. The electric energy generated by the new energy power generation module (6) and the gas turbine (15) is connected to the municipal distribution network (7) for powering the thermal storage steam heating system (4) or supplying power to the outside. The flue gas generated by the gas turbine (15) is transported to the thermal storage steam heating system (4) for waste heat recovery. The hot water supply pipeline (10) is connected to the absorption heat pump system (5) after heat exchange with the absorber (54) and condenser (52) inside the absorption heat pump system (5), and is used to supply hot water to the hot water user (13). The cold supply pipeline (11) is connected to the absorption heat pump system (5) after heat exchange with the evaporator (55) inside the absorption heat pump system (5), and is used to provide cold energy to the cold energy user (14).

2. A distributed multi-generation system coupling green electricity and heat storage according to claim 1, characterized in that: The thermal storage steam heating system (4) is composed of a thermal storage preheater (41), a thermal storage steam generator (42), a steam-water separator (43) and a thermal storage superheater (44) connected in series. The steam-water mixture of the thermal storage steam generator (42) enters the steam-water separator (43) to separate into saturated water and saturated steam, wherein the saturated water flows back to the thermal storage preheater (41), and the saturated steam passes through the thermal storage superheater (44) to be heated to superheated steam and then output from the steam outlet; wherein the thermal storage preheater (41) and the thermal storage steam generator (42) are both dual heat source elements, which can use the electricity provided by the municipal distribution network (7) for electrical heat storage, and can also use the high-temperature waste heat flue gas generated by the gas turbine (15) to heat the internal heat storage body, and the thermal storage superheater (43) uses the electricity provided by the municipal distribution network (7) to electrically heat the internal heat storage body.

3. A distributed multi-generation system coupling green electricity and heat storage according to claim 2, characterized in that: The electricity provided by the municipal distribution network (7) to the thermal storage steam heating system (4) comes from the clean energy electricity generated by the new energy power generation module (6), or the valley electricity directly provided by the municipal distribution network (7).

4. A distributed multi-generation system coupling green electricity and heat storage according to claim 3, characterized in that: The heat storage preheater (41) and the heat storage steam generator (42) preferentially use the high-temperature waste heat flue gas generated by the gas turbine (15) to heat the internal heat storage body. When the waste heat resources do not meet the minimum heating load, the electricity provided by the municipal distribution network (7) is used for electric heating to make up for the shortfall.

5. A distributed multi-generation system coupling green electricity and heat storage according to claim 3, characterized in that: When the municipal distribution network (7) provides electricity to the thermal storage steam heating system (4), the clean energy electricity generated by the new energy power generation module (6) is preferentially used; when the clean energy electricity generated by the new energy power generation module (6) is insufficient, the clean energy electricity is combined with the municipal electricity provided by the municipal distribution network (7) for mixed power supply.

6. A distributed multi-generation system coupling green electricity and heat storage according to claim 2, characterized in that: The heat storage preheater (41), the heat storage steam generator (42) and the heat storage superheater (44) are all filled with solid heat storage bodies for heat storage. The material of the solid heat storage body is a solid sensible heat storage material or a composite heat storage material based on a solid sensible heat material and doped with a phase change material, and the maximum heat storage temperature is not less than 400°C.

7. A distributed multi-generation system coupling green electricity and heat storage according to claim 1, characterized in that: The absorption heat pump system (5) comprises a high temperature generator (51), a condenser (52), a heat exchanger (53), an absorber (54) and an evaporator (55), wherein the high temperature generator (51), the condenser (52), the evaporator (55) and the absorber (54) are connected in sequence to form a circulation loop, and two streams of working fluid bidirectionally transported between the high temperature generator (51) and the absorber (54) are heat exchanged through the heat exchanger (53), and heat exchange is formed between the absorber (54) and the condenser (52) and the hot water supply pipeline (10).

8. A distributed multi-generation system coupling green electricity and heat storage according to claim 1, characterized in that: The new energy power generation module (6) comprises at least one of a photovoltaic power generation module and a small wind power generation module.

9. A distributed multi-generation system coupling green electricity and heat storage according to claim 1, characterized in that: The gas turbine (15) is a distributed gas turbine.

10. A method for combined cooling, heating and power generation using a distributed multi-generation system coupling green electricity and heat storage as claimed in any one of claims 1 to 9, characterized in that: When the power load of the power grid is in a valley power state, the clean energy power generated by the new energy power generation module (6) is directly used to heat the heat storage body inside the heat storage preheater (41), the heat storage steam generator (42) and the heat storage superheater (44) in the heat storage steam heating system (4) through the municipal distribution network (7), thereby realizing direct consumption of the clean energy power; when the power generation power of the new energy power generation module (6) is insufficient to fully charge the heat storage steam heating system (4), the heat storage steam heating system (4) is further electrically stored with valley power provided by the municipal distribution network (7); when the power load of the power grid is in a valley power state, the heat storage steam heating system (4) is always kept storing heat at the maximum heating power load until the heat storage system is fully charged; When the power load of the power grid is at peak power, the power generated by the new energy power generation module (6) is supplied to the outside through the municipal distribution network (7), and when the price of gas-fired power generation is lower than the peak power price of the distribution network, the gas turbine (15) is controlled to be in a working state, and the power generated by the gas turbine (15) is supplied to the outside through the municipal distribution network (7) to achieve the purpose of peak load regulation, and the high-temperature flue gas waste heat generated by the gas turbine (15) is used to heat the heat storage preheater (41) and the heat storage steam generator (42) in the heat storage steam heating system (4); when the storage When the thermal steam heating system (4) has a heating load and the heat storage is insufficient to meet the heating demand, the thermal storage steam heating system (4) is controlled to perform heating at the lowest heating load demand, and the high-temperature flue gas waste heat generated by the gas turbine (15) is preferentially used for heating. If the waste heat resource cannot meet the lowest heating load demand of the thermal storage steam heating system (4), it is necessary to further use the electricity provided by the municipal distribution network (7) to make up for the load gap, and the electricity comes from the clean energy electricity generated by the new energy power generation module (6) or the direct power supply of the municipal distribution network (7); When it is necessary to supply steam and cold load to the outside, the water in the buffer water supply tank (2) is pressurized by the circulating booster water pump (3) and then flows into the thermal storage steam heating system (4) for heat exchange to generate superheated steam, one path of the superheated steam being directly supplied to the steam user (12) through the steam main pipeline (8), and the other path of the superheated steam being input into the high temperature generator (51) of the absorption heat pump (5) as the driving heat source of the heat pump cycle; on the one hand, the make-up water is heated in two stages through the absorber (54) and the condenser (52) through the hot water supply pipeline (10), and then low-grade domestic hot water and heating are provided to the hot water user (13); on the other hand, the internal working fluid is cooled by heat exchange through the evaporator (55) through the cold supply pipeline (11), and then cold energy is provided to the cold energy user (14).

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