Boiler peak shift heat supply system and its operating method

Abstract

This application provides a boiler peak shift heat supply system and a method for operating the same, the boiler peak shift heat supply system comprising a heat pump assembly, a power generation assembly, and a boiler assembly, wherein the heat pump assembly comprises a mechanical heat pump unit and an absorption heat pump unit, the number of absorption heat pump units being at least one, the mechanical heat pump unit being connected to the output terminal of the power generation assembly via a clutch mechanism, the boiler assembly comprising a cyclically communicating boiler unit and a steam turbine unit, the steam turbine unit being connected to the power generation assembly and the absorption heat pump unit, the heat generated when the boiler unit is operating being transported to the power generation assembly and the absorption heat pump unit, respectively via the steam turbine unit, and the power generation assembly can achieve a variable load by the mechanical heat pump unit when the clutch mechanism is in communication. The boiler peak shift heat supply system can achieve an excellent peak shift effect when meeting heat supply demand.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the priority of a Chinese patent application with application number 202410209451X and invention title "Boiler Peak - Shift Heat Supply System and Its Operation Method", which was filed with the Chinese Patent Office on February 26, 2024, and the entire content of which is incorporated herein by reference.

[0002] [Technical Field] This application relates to the technical field of deep peak - shifting and combined heat supply, and particularly to a boiler peak - shift heat supply system and its operation method.

Background Art

[0003] China needs to deepen reforms to its power system and build a new type of power system based on new energy in order to build a clean, low-carbon, safe, and efficient energy system, control the total amount of fossil fuels used, work to improve utilization efficiency, and implement renewable energy substitution actions. Due to the unpredictability and discontinuity of renewable energy generation, unstable generation affects the power quality of the transmission grid, resulting in some renewable energy generation being unable to enter the grid and causing the phenomenon of "solar and wind power output curtailment." How to accommodate and process the wasted electricity is a problem that needs to be solved urgently now. To solve the problem of the low proportion of renewable energy generation connected to the power grid, peak shifting by thermal power generation units with a high proportion of generation has become an effective method for accommodating and processing renewable energy electricity. Currently, the minimum load of boilers in China's coal-fired power generation units during daily operation is 40-50% of the rated load, which is still far from the world's advanced level of 20-30% of the minimum technical output in countries such as Germany and Denmark. Given the characteristics of China's energy resource structure, coal-fired power plants will continue to exist for a long time. Therefore, it is necessary for coal-fired power plants to be involved in peak shifting in order to provide more high-quality, flexible peak-shift power sources, realize joint power generation with conventional and new energy sources, and build a reliable and flexible power system.

[0004] Boiler units sometimes need to provide heat during winter, and due to the inherent coupling relationship between heat and power output of thermal power generation units, especially back-pressure units, the amount of power generated under the corresponding heat load is limited, resulting in poor peak-shifting performance. Heat pumps, as highly efficient and energy-saving devices, can make full use of low-grade thermal energy, and can obtain a large amount of high-grade heat with a small amount of reverse circulation net output, effectively utilizing low-grade heat that is normally difficult to use.

[0005] Based on the above characteristics, it is necessary to develop a technology that combines heat pump technology with the unit to take advantage of its peak shift and heat supply benefits. This involves achieving the effect of generating heat using the heat pump under the same heat load, thereby reducing the power generation of the electric field unit and achieving deep peak shift. [Overview of the project] [Problems that the invention aims to solve]

[0006] This application aims to solve, at least to some extent, one of the technical problems in related technologies. [Means for solving the problem]

[0007] To this end, the embodiments of the present invention propose a boiler peak shift heat supply system and a method of operating the same, which can achieve an excellent peak shift effect when meeting heat supply demand.

[0008] A boiler peak shift heat supply system according to an embodiment of the present invention includes a heat pump assembly, a power generation assembly, and a boiler assembly, wherein the heat pump assembly includes a mechanical heat pump unit and an absorption heat pump unit, the number of absorption heat pump units being at least one, the mechanical heat pump unit being connected to the output terminal of the power generation assembly via a clutch mechanism, the boiler assembly includes a cyclically communicating boiler unit and a steam turbine unit, the steam turbine unit being connected to the power generation assembly and the absorption heat pump unit, the heat generated when the boiler unit is operating being transported to the power generation assembly and the absorption heat pump unit, respectively via the steam turbine unit, and the power generation assembly achieving a variable load by the mechanical heat pump unit when the clutch mechanism is in communication.

[0009] According to the boiler peak shift heat supply system of the present invention, the clutch mechanism enables flexible operation of the boiler assembly during deep peak shifts, and during periods of low-load operation of the power grid, the absorption heat pump unit generates heat of various grades for residential and industrial use, realizing efficient cascaded use of energy, resulting in high economic benefits, being more environmentally friendly, and contributing to the reduction of energy waste. Flexible adjustment of heat supply and power generation is achieved by changing the distribution of the working fluid, and when the power grid needs to change loads quickly, the mechanical heat pump unit is started to generate a large amount of low-temperature heat for residential heat supply in the mechanical heat pump heat supply system, mitigating problems of heat supply and industrial heat shortages in winter, and rapidly reducing the electrical load supplied to the power grid, thereby enabling a rapid deep peak shift of the unit.

[0010] In some embodiments, the steam turbine unit and the absorption heat pump unit are connected via a plurality of extraction circuits, and one of the extraction circuits is provided with an adjustable intermediate pressure composite control valve.

[0011] In some embodiments, the extraction circuit includes a plurality of extraction branch lines and an extraction main line, one of which is provided with a check valve and an electric gate valve, all of which are connected to the extraction main line, and the extraction main line is connected to the absorption heat pump unit.

[0012] In some embodiments, the steam turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder connected in sequence, and each of the high-pressure cylinder, the intermediate-pressure cylinder, and the low-pressure cylinder includes a plurality of extraction heating assemblies. The extraction heating assembly includes extraction stage groups and heaters, all of which are arranged sequentially in the axial direction of the steam turbine unit. A reheater is provided between the high-pressure cylinder and the medium-pressure cylinder, and two adjacent groups of extraction stages are connected via the reheater.

[0013] In some embodiments, the intermediate-pressure cylinder includes two extraction heating assemblies, the two adjacent extraction heating assemblies are connected via an intermediate-pressure reflux assembly, the intermediate-pressure reflux assembly includes, in sequence, an intermediate-pressure reflux extraction stage group, a deaerator, and a feedwater pump group, the intermediate-pressure reflux extraction stage group is arranged coaxially with the extraction stage group of the two adjacent extraction heating assemblies, the deaerator is connected to the heater of the downstream intermediate-pressure cylinder, and the feedwater pump group is connected to the heater of the upstream intermediate-pressure cylinder. and / or, the low-pressure cylinder includes two extraction heating assemblies and a final stage extraction assembly located downstream of the two extraction heating assemblies, the final stage extraction assembly including a final stage extraction stage group, an air-cooled condenser, and a condensate pump, the final stage extraction stage group being coaxially arranged with the extraction stage group of the low-pressure cylinder, and the air-cooled condenser being connected to the heater of an adjacent low-pressure cylinder via the condensate pump.

[0014] In some embodiments, the intermediate pressure reflux extraction stage group and the air-cooled condenser are connected via a small steam turbine, and a portion of the working fluid in the intermediate pressure reflux extraction stage group flows into the small steam turbine to drive the feedwater pump group.

[0015] In some embodiments, an electric valve is provided between the small steam turbine and the intermediate-pressure recirculation extraction stage group.

[0016] In some embodiments, the steam turbine unit further includes a mixing pipeline, the mixing pipeline located between two adjacent heaters and / or between adjacent heaters and the deaerator and / or between adjacent heaters and the air-cooled condenser. The heat-exchanged working fluid in the heater located downstream can be mixed by the mixing pipeline with the unheat-exchanged working fluid in any one of the heater, deaerator, and air-cooled condenser located upstream.

[0017] In some embodiments, the clutch mechanism is an electromagnetic clutch.

[0018] The embodiments of the present invention further provide an operating method for operating the boiler peak shift heat supply system described above. The steps include acquiring the load status of the boiler peak shift heat supply system, The procedure includes the step of disconnecting the connection between the power generation assembly and the mechanical heat pump unit when the boiler peak shift heat supply system is in a low-load state.

[0019] According to the boiler peak shift heat supply system operation method of the embodiment of the present invention, it is possible to determine whether or not to perform a deep peak shift depending on the load condition of the boiler peak shift heat supply system, and if a deep peak shift is necessary, the electrical load supplied to the power grid can be reduced by connecting the mechanical heat pump unit, thereby enabling a rapid deep peak shift of the unit. This operation method achieves high-precision matching of power supply and heat supply, enabling a deep peak shift and achieving a better heat supply effect.

[0020] To more clearly describe the embodiments of the present application or the technical solutions of the prior art, the drawings necessary for describing the embodiments or the prior art will be briefly described below. As will be clear, the drawings described below are only a few embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic diagram of the overall structure of the boiler peak shift heat supply system according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of the structure of the mechanical heat pump unit of the boiler peak shift heat supply system according to an embodiment of the present invention. [Figure 3] This is a schematic diagram of the structure of the absorption heat pump unit of the boiler peak shift heat supply system according to an embodiment of the present invention. [Figure 4] This is a flowchart of an operation method of a boiler peak shift heat supply system according to an embodiment of the present application.

Embodiments for Carrying out the Invention

[0022] Hereinafter, embodiments of the present application will be described in detail, and examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are used for interpreting the present application and should not be understood as limiting the present application.

[0023] Hereinafter, a boiler peak shift heat supply system according to an embodiment of the present application and its operation method will be described with reference to FIGS. 1 to 4.

[0024] Embodiments of the present application provide a boiler peak shift heat supply system. As shown in FIGS. 1 to 3, the boiler peak shift heat supply system includes a heat pump assembly, a power generation assembly 3, and a boiler assembly. The heat pump assembly includes a mechanical heat pump unit 1 and an absorption heat pump unit 2. The number of absorption heat pump units 2 is at least one. The mechanical heat pump unit1 is connected to the output end of the power generation assembly 3 via a clutch mechanism 4. The boiler assembly includes a boiler unit 5 and a steam turbine unit 6 that are connected in a circulating manner. The steam turbine unit 6 is connected to the power generation assembly and the absorption heat pump unit 2. The heat generated when the boiler unit 5 operates is transported to the power generation assembly 3 and the absorption heat pump unit 2 respectively via the steam turbine unit 6. When the clutch mechanism 4 is in a communicating state, the power generation assembly 3 realizes a variable load by the mechanical heat pump unit 1.

[0025] The boiler peak shift heat supply system, through its clutch mechanism 4, enables flexible operation of the boiler assembly during deep peak shifts. During periods of low-load operation of the power grid, the absorption heat pump unit 2 generates heat of various grades for residential and industrial use, achieving efficient cascaded energy utilization. This results in high economic benefits, is more environmentally friendly, and contributes to reducing energy waste. Flexible adjustment of heat supply and power generation is achieved by changing the distribution of the working fluid. When the power grid needs to rapidly change loads, the mechanical heat pump unit 1 is initiated to generate a large amount of low-temperature heat for residential use in the mechanical heat pump heat supply system, mitigating winter heat supply and industrial heat shortage problems, and rapidly reducing the electrical load supplied to the power grid, enabling rapid deep peak shifts of the unit.

[0026] The boiler peak shift heat supply system can operate the unit flexibly by switching according to different loads, can respond quickly when the power grid switches from normal to peak conditions, and improves the deep peak shift response speed of the boiler peak shift heat supply system and the economic benefits of operating the unit by combining it with a heat pump assembly.

[0027] Furthermore, the heat generated when the boiler unit 5 operates is transported into the steam turbine unit 6 in the form of a working fluid, and then transported to the power generation assembly 3 and the absorption heat pump unit 2, respectively, by a single or multiple distribution, thereby realizing power generation and heat supply functions.

[0028] Specifically, the working fluid may be steam.

[0029] To facilitate the connection between the steam turbine unit 6 and the absorption heat pump unit 2, in some embodiments, the steam turbine unit 6 and the absorption heat pump unit 2 are connected via a plurality of extraction circuits 61, and one of the extraction circuits 61 is provided with an adjustable intermediate pressure composite control valve 613.

[0030] The above-mentioned intermediate-pressure composite control valve 613 adjusts the flow rate of the working fluid passing through it by adjusting its opening degree, thereby achieving the objective of adjusting the amount of steam extracted for heat supply. In one embodiment, the larger the opening degree of the intermediate-pressure composite control valve 613, the more steam is extracted, and the better the heat supply effect of the absorption heat pump unit 2.

[0031] In some embodiments, the extraction circuit 61 includes a plurality of extraction branch lines 611 and an extraction main line 612, with a check valve 6111 and an electric gate valve 6112 provided in any one of the extraction branch lines 611, and all of the extraction branch lines 611 are connected to the extraction main line 612, which is connected to the absorption heat pump unit 2.

[0032] The number of extraction branch lines 611 described above is at least two, and may be three or more. Generally, the extraction branch lines 611 are selectively connected to the extraction main line 612, and different extraction branch lines 611 are connected to different locations on the steam turbine unit 6 to obtain high-temperature working fluids with different temperatures. By selecting different extraction branch lines 611, different high-temperature working fluids can be obtained, and furthermore, heat supply heat sources with different temperatures can be output, meeting the demands of different users and realizing efficient cascaded use of energy.

[0033] The above-mentioned electric gate valve 6112 can help prevent the recirculation of the generated water into the steam turbine unit 6.

[0034] Specifically, because the steam pressure at the end of the extraction circuit 61 is low, when the pressure inside the pipe changes, the steam located inside is more likely to liquefy into water and flow back into the steam turbine unit 6. The electric gate valve 6112 and check valve 6111 can overcome the above problem.

[0035] In some embodiments, the steam turbine unit 6 includes a high-pressure cylinder 62, a medium-pressure cylinder 63, and a low-pressure cylinder 64, and when connecting the steam turbine unit 6 to the absorption heat pump unit 2, one or more of the three cylinders having different pressures can be selected and connected to the absorption heat pump unit 2.

[0036] The structure of the boiler peak shift heat supply system in this embodiment will be described in detail below, using the example that the steam turbine unit 6 is connected to the absorption heat pump unit 2 via the intermediate pressure cylinder 63.

[0037] As shown in Figure 1, the boiler assembly includes a boiler unit 5 and a steam turbine unit 6 that are circulatingly connected. Water flows into the boiler unit 5 and absorbs heat to form high-temperature, high-pressure steam, which then enters the steam turbine unit 6 to perform work. Specifically, the steam turbine unit 6 includes a high-pressure cylinder 62, an intermediate-pressure cylinder 63, and a low-pressure cylinder 64 connected in sequence. Each of the high-pressure cylinder 62, intermediate-pressure cylinder 63, and low-pressure cylinder 64 includes a plurality of extraction heating assemblies 65. Each extraction heating assembly 65 includes an extraction stage group 651 and a heater 652. All extraction stage groups 651 are arranged sequentially in the axial direction of the steam turbine unit 6. A reheater 66 is provided between the high-pressure cylinder 62 and the intermediate-pressure cylinder 63. Two adjacent extraction stage groups 651 are connected via the reheater 66, and the low-pressure cylinder 64 is connected to the power generation assembly 3.

[0038] Specifically, the reheater 66 is a device that reheats the work-used working fluid, whose temperature and pressure have decreased, into high-temperature, medium-pressure steam, contributing to improved thermal efficiency and increased thermal output of the steam turbine unit 6. As shown in Figure 1, of the gas flowing out of the high-pressure cylinder 62, only a small portion is used for extraction, while the majority of the steam is sent to the reheater 66 for heating.

[0039] In some embodiments, the intermediate pressure cylinder 63 includes two extraction heating assemblies 65, the two adjacent extraction heating assemblies 65 connected via an intermediate pressure reflux assembly 67, the intermediate pressure reflux assembly 67 including an intermediate pressure reflux extraction stage group 671, a deaerator 672, and a feedwater pump group connected in sequence, the intermediate pressure reflux extraction stage group 671 being coaxial with the extraction stage group 651 of the two adjacent extraction heating assemblies 65, the deaerator 672 being connected to the heater 652 of the downstream intermediate pressure cylinder 63, and the feedwater pump group being connected to the upstream intermediate pressure cylinder The low-pressure cylinder 64 is connected to the heater 652 of the Linda 63 and / or includes two extraction heating assemblies 65 and a final stage extraction assembly 68 located downstream of the two extraction heating assemblies 65, the final stage extraction assembly 68 including a final stage extraction stage group 681, an air-cooled condenser 682, and a condensate pump 683, which are connected in sequence, the final stage extraction stage group 681 being coaxial with the extraction stage group 651 of the low-pressure cylinder 64, and the air-cooled condenser 682 being connected to the heater 652 of the adjacent low-pressure cylinder 64 via the condensate pump 683.

[0040] Specifically, the water supply pump group includes a booster pump 673 and a water supply pump 674, and the two pumps can perform two pressurization processes on the water, thereby gradually increasing the water pressure and improving circulation in the equipment, and / or a slug cooler is further provided between the condensate pump 683 and the low-pressure heater 652.

[0041] In some embodiments, the intermediate pressure reflux extraction stage group 671 and the air-cooled condenser 682 are connected via a small steam turbine 675, and a portion of the working fluid in the intermediate pressure reflux extraction stage group 671 flows into the small steam turbine 675 to drive the feedwater pump group.

[0042] Specifically, in some embodiments, a two-stage extraction heating assembly 65 is provided within the high-pressure cylinder 62.

[0043] The high-temperature, high-pressure steam generated in the boiler unit 5 flows sequentially into the high-pressure cylinder 62, the medium-pressure cylinder 63, and the low-pressure cylinder 64. The steam flowing into the first-stage extraction heating assembly 65 of the high-pressure cylinder 62 is divided into two parts: one part flows into the extraction unit of the second-stage extraction heating assembly 65, and the other part is used as extraction #1 as the steam source (used to supply heat) for the heater 652 of the first-stage extraction heating assembly 65. The steam flowing into the second-stage extraction heating assembly 65 is also divided into two parts: one part enters the reheater 66 and is heated, and the other part is used as extraction #2 as the steam source for the heater 652 of the second-stage extraction heating assembly 65. The steam heated by the heater 652 is medium-pressure, high-temperature steam and can enter the medium-pressure cylinder 63 to perform work.

[0044] The steam entering the intermediate-pressure cylinder 63 is similarly divided into two parts by a third extraction process within the first-stage extraction heating assembly 65. One part flows into the intermediate-pressure reflux extraction stage group 671 of the intermediate-pressure reflux assembly 67 by a fourth extraction process, and the other part is used as extraction #3 as the steam source for the heater 652 of the first-stage extraction heating assembly 65. A portion of the steam that flows into the intermediate-pressure reflux assembly 67 flows into the deaerator 672 and the small steam turbine 675 by extraction #4 and extraction #5, respectively. The steam that flows into the small steam turbine 675 is then used for the small steam turbine 6 The small steam turbine 675 can function as a power source to drive 75, and can be used to drive a group of feedwater pumps. The gas that flows into the deaerator 672 is processed and then processed by the group of feedwater pumps before flowing into the heater 652 of the extraction heating assembly 65, where it may be heated. The remaining gas after the two extractions flows into the second stage extraction heating assembly 65, where it is similarly divided into two parts: one part flows out from the intermediate pressure cylinder 63, and the other part flows into the heater 652 of the second stage extraction heating assembly 65 via extraction #6.

[0045] A portion of the steam flowing out of the intermediate-pressure cylinder 63 enters the low-pressure cylinder 64 and flows sequentially through the first-stage extraction heating assembly 65 and the second-stage extraction heating assembly 65 located within the low-pressure cylinder 64 (this is consistent with the above, passing through extraction #7 and extraction #8 in order, and redundant explanations are omitted here). The remaining gas then flows into the final-stage extraction assembly 68, and the generated waste steam enters the air-cooled condenser 682. The waste steam that enters the air-cooled condenser 682 is condensed and then sent sequentially via the condensate pump 683 to the heater 652 of the second-stage extraction heating assembly 65 and the heater 652 of the first-stage extraction heating assembly 65, and finally flows into the heater 652 of the second-stage extraction heating assembly 65 of the intermediate-pressure cylinder 63.

[0046] The water in the heater 652 of the second stage extraction heating assembly 65 of the intermediate pressure cylinder 63 is treated by the deaerator 672, then transported by the feedwater pump group to the heater 652 of the first stage extraction heating assembly 65 of the same cylinder, and further flows into the high-pressure cylinder 62 via the associated pipeline, where it is treated by the heater 652 in the high-pressure cylinder 62 before being re-flowed into the boiler unit 5.

[0047] In the above circulation process, the generated condensed water can be converted into steam through endothermic treatment at each stage, allowing the above work process to be circulated.

[0048] In the process of circulating the above work, the remaining waste steam after the small steam turbine 675 has finished its work also flows into the air-cooled condenser 682 and is condensed.

[0049] In some embodiments, an electric valve 676 is provided between a small steam turbine 675 and an intermediate-pressure recirculation extraction stage group 671.

[0050] In some embodiments, the steam turbine unit 6 further includes a mixing pipeline 69 located between two adjacent heaters 652 and / or between an adjacent heater 652 and a deaerator 672 and / or between an adjacent heater 652 and an air-cooled condenser 682, wherein the heat-exchanged working fluid in the downstream heater 652 can be mixed by the mixing pipeline 69 with the unheat-exchanged working fluid in any one of the upstream heaters 652, deaerator 672 and air-cooled condenser 682.

[0051] The above mixing process is used to remix the working fluid after heat exchange treatment with the working fluid that has not undergone heat exchange treatment in the next stage, thereby achieving efficient heat exchange of the working fluid and contributing to avoiding heat waste.

[0052] In some embodiments, the clutch mechanism 4 is an electromagnetic clutch.

[0053] The following describes the structures of the mechanical heat pump unit 1 and the absorption heat pump unit 2.

[0054] The structure of the mechanical heat pump unit 1, as shown in Figure 2, includes a first evaporator 101, a compressor 102, a working fluid heat exchanger 103, and an expansion valve 104. When it is necessary to rapidly change the load during a deep peak shift of the unit and low-temperature heat supply is required, the mechanical heat pump unit 1 can consume surplus power and supply the necessary heat to the heat user.

[0055] The specific measures are as follows:

[0056] The electromagnetic clutch connected to the output terminal (i.e., rotor) of the power generation assembly 3 is turned on, and the mechanical heat pump system connected to it is put into operation. At this time, the working fluid of the system is pressurized by the compressor 102 to become a high-temperature, high-pressure working fluid. After that, it is cooled by the working fluid heat exchanger 103 to release heat, and after being further cooled by the expansion valve 104, it enters the first evaporator 101 to absorb heat. After that, the working fluid flows into the compressor 102 and becomes high-temperature, high-pressure steam by doing work.

[0057] The above circulation process is repeated, and the external low-temperature working fluid absorbs heat after passing through the working fluid heat exchanger 103, becoming a low-temperature heat source supplied to the heat user, and efficiently generating heat through the heat pump. In addition, the mechanical heat pump device acts directly on the rotor of the power generation unit, and can rapidly reduce the axial work of the steam turbine unit 6 on the power generation unit, thereby enabling rapid load changes during deep peak shifts. The mechanical heat pump heat supply system increases or decreases the heat supply load by adjusting the discharge pressure and flow rate of the compressor 102.

[0058] In some embodiments, the steam turbine unit 6 is connected to the absorption heat pump unit 2 via an intermediate pressure cylinder 63. As shown in Figure 1, in this case, the three different groups of intermediate pressure cylinders 63 are all connected to the absorption heat pump unit 2 via a return branching path, and an intermediate pressure composite control valve 613 is also provided in the extraction circuit 61. When one valve is on, the valves in the other pipelines are all off.

[0059] The absorption heat pump unit 2 is a lithium bromide absorption heat pump, and its structure is as shown in Figure 3. The absorption heat pump unit 2 uses steam as an external heat source and supplies heat to the generator 201 via a heat exchanger. As a result, the steam in the lithium bromide solution inside absorbs heat and evaporates, becoming high-temperature steam. This steam enters the high-temperature heat exchanger, exchanges heat with the working fluid, passes through the throttle valve 208, becomes low-temperature working fluid, absorbs heat in the second evaporator 203, and enters the solution mixer 204. The concentrated solution formed in the generator 201 releases heat via the solution heat exchanger 207, then passes through the throttle valve 208 and mixes with the heat-absorbing water in the solution mixer 204 to become a diluted solution. After releasing heat via the low-temperature heat exchanger 205, it enters the solution heat exchanger 207 via the working fluid pump for preheating, and then enters the generator 201 to complete the circulation. The external low-temperature working fluid becomes a high-temperature working fluid after passing through the low-temperature heat exchanger 205 and the high-temperature heat exchanger 202, thereby transporting heat to the user.

[0060] In the heat supply process, the amount of steam supplied to the absorption heat pump unit 2 can be controlled by controlling the opening degree of the intermediate pressure composite control valve 613. Furthermore, by combining this with components such as the solution pump 206, the flow rate of the working fluid can be effectively changed, thereby altering the heat load of the heat supply.

[0061] This absorption heat pump can generate a large amount of intermediate heat using a small amount of high-temperature heat source, and by having multiple different extraction temperatures, it can output heat supply heat sources with different temperatures using high-temperature heat sources with different temperatures. This allows it to be used by users with diverse needs, and enables efficient cascading use of energy. Compared to conventional technical solutions, it offers higher economic benefits and can also meet higher environmental considerations.

[0062] In other words, in some embodiments, the heat supply amount and heat supply quality of the boiler peak shift heat supply system are not only determined according to the power grid peak shift requirements and heat supply demand, but the switching adjustment can also be performed by switching valves in the pipeline.

[0063] Of course, the type and number of absorption heat pumps mentioned above can be flexibly adjusted according to the local heat supply demand, thereby enabling the simultaneous output of heat of various qualities to the outside.

[0064] Alternatively, the air-cooled condenser 682 and other equipment capable of releasing heat to the outside may be fitted with a heat pump structure having a low-temperature heat absorption function to make full use of the waste heat of the power plant. If the unit is not involved in peak shifting and there is no heat supply demand, the extraction circuit 61 is directly turned off, the check valves 6111 and motorized gate valves 6112 in all extraction branch lines 611 are turned off, and the opening of the intermediate pressure composite control valve 613 is adjusted to the maximum, at which point the system can operate normally.

[0065] As can be understood, the boiler peak shift heat supply system according to this embodiment provides a system that can rapidly change the load to power generation equipment requiring heat supply and deep peak shift, thereby deepening the peak shift, using a mechanical heat pump unit 1 and an absorption heat pump unit 2. By combining the boiler peak shift heat supply system with the heat pump assembly, the energy utilization efficiency can be improved and the economics of heat supply can be enhanced, and energy cascading utilization can be achieved by generating energy of different grades by using extracted air at different locations as the driving heat source for the absorption heat pump. The boiler peak shift heat supply system can effectively improve the flexible operating capability of the unit, can respond quickly when the load is switched on the power grid, improves the load response speed of the heat supply unit, and is of great significance in improving the service level of the power system and the economic benefits of the heat supply system.

[0066] The embodiment of the present invention further provides an operating method for operating the boiler peak shift heat supply system described above, as shown in Figure 4, Step S1 involves acquiring the load status of the boiler peak shift heat supply system, The system includes step S2, which disconnects the connection between the power generation assembly 3 and the mechanical heat pump unit 1 when the boiler peak shift heat supply system is in a low-load state.

[0067] The operating method for the boiler peak shift heat supply system according to the embodiment of the present invention determines whether or not to perform a deep peak shift depending on the load state of the boiler peak shift heat supply system. If a deep peak shift is necessary, the electrical load supplied to the power grid is reduced by connecting the mechanical heat pump unit 1, thereby enabling a rapid deep peak shift of the unit. This operating method achieves high-precision matching of power supply and heat supply, enabling a deep peak shift and achieving a superior heat supply effect.

[0068] Specifically, the mechanical heat pump unit 1 is primarily used for rapid load changes in the power grid. By connecting the mechanical heat pump unit 1, low-temperature heat for residential heat supply can be generated, mitigating problems with winter heat supply and industrial heat shortages. It also rapidly reduces the electrical load supplied to the power grid, enabling rapid deep peak shifting of the boiler peak shift heat supply system. In other operating stages (low-load operation and normal permissible stages), the absorption heat pump unit 2 obtains heat sources with different temperatures by extracting air from different parts of the steam turbine unit 6, generating medium-to-high temperature heat of different grades for residential and industrial use. In this case, the boiler peak shift heat supply system can generate a large amount of intermediate heat using a small amount of high-temperature heat source and supply it to different heat users, achieving efficient cascading use of energy, resulting in high economic benefits and meeting environmental considerations.

[0069] In the description of this application, it is important to understand that the directions or positional relationships indicated by terms such as "center," "vertical direction," "horizontal direction," "length," "width," "thickness," "top," "bottom," "front," "back," "left," "right," "perpendicular," "horizontal," "top," "bottom," "inside," "outside," "clockwise," "counterclockwise," "axial direction," "radial direction," and "circumferential direction" are directions or positional relationships based on the illustrations and are intended solely for the convenience and simplification of the description of this application. They do not indicate or imply that such devices or elements necessarily have a specific direction or are configured and operated in a specific direction, and therefore cannot be understood as limiting the present application.

[0070] Furthermore, the terms “first” and “second” are used solely for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features being referred to. Therefore, features limited by “first” and “second” may explicitly or implicitly include at least one such feature. In this description, unless otherwise specifically stated, “plural” means at least two, for example, two, three, etc.

[0071] In this application, unless otherwise specified or limited, terms such as "attachment," "connection," "bonding," and "fixing" should be understood in a broad sense. For example, unless otherwise specified, these may be fixed connections, detachable connections, or integrated connections; mechanical connections, electrical connections, or interconnected connections; direct connections, indirect connections via an intermediate medium, or internal communication between two elements or an interaction relationship between two elements. Those skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0072] In this application, unless otherwise specified or limited, the presence of a first feature "above" or "below" a second feature may mean that the first and second features are in direct contact or indirectly in contact via an intermediate medium. Furthermore, the presence of a first feature "above," "above," and "on the top surface" of a second feature may simply indicate that the first feature is directly above or diagonally above the second feature, or that the horizontal height of the first feature is greater than that of the second feature. The presence of a first feature "below," "below," and "on the bottom surface" of a second feature may simply indicate that the first feature is directly below or diagonally below the second feature, or that the horizontal height of the first feature is lower than that of the second feature.

[0073] In this application, terms such as “one embodiment,” “several embodiments,” “example,” “specific example,” or “several examples” mean that the specific features, structures, materials, or properties described in conjunction with such embodiment or example are included in at least one embodiment or example of this application. In this specification, the exemplary expressions of the above terms do not have to apply to the same embodiment or example. The specific features, structures, materials, or properties described can be appropriately combined in any one or more embodiments or examples. Furthermore, a person skilled in the art can combine or link different embodiments or examples and features of different embodiments or examples described herein, provided that they do not conflict with each other.

[0074] Although embodiments of the present application have been described above, it should be understood that these embodiments are illustrative and should not be understood as limiting the present application. Those skilled in the art may modify, alter, substitute, or otherwise change the embodiments within the scope of the present application. [Explanation of symbols]

[0075] 1. Mechanical heat pump unit; 101. First evaporator; 102. Compressor; 103. Working fluid heat exchanger; 104. Expansion valve; 2. Absorption heat pump unit; 201. Generator; 202. High-temperature heat exchanger; 203. Second evaporator; 204. Solution mixer; 205. Low-temperature heat exchanger; 206. Solution pump; 207. Solution heat exchanger; 208. Throttle valve; 3. Power generation assembly; 4. Clutch mechanism; 5. Boiler unit; 6. Steam turbine unit; 61. Extraction circuit; 611. Extraction branch line; 6111. Check valve; 6112. Electric gate valve; 612. Extraction main line; 613. Intermediate pressure combined control valve; 62. High pressure cylinder; 63. Intermediate pressure cylinder; 64. Low pressure cylinder; 65. Extraction heating assembly; 651. Extraction stage group; 652. Heater; 66. Reheater; 67. Intermediate pressure reflux assembly; 671. Intermediate pressure reflux extraction stage group; 672. Deaerator; 673. Booster pump; 674. Feedwater pump; 675. Small steam turbine; 676. Electric valve; 68. Final stage extraction assembly; 681. Final stage extraction stage group; 682. Air-cooled condenser; 683. Condensate pump; 69. Mixing pipeline.

Claims

1. A boiler peak shift heat supply system comprising a heat pump assembly, a power generation assembly (3), and a boiler assembly, The heat pump assembly includes a mechanical heat pump unit (1) and an absorption heat pump unit (2), wherein the number of absorption heat pump units (2) is at least one. The mechanical heat pump unit (1) is connected to the output terminal of the power generation assembly (3) via a clutch mechanism (4). The boiler assembly includes a cyclically connected boiler unit (5) and a steam turbine unit (6), the steam turbine unit (6) being connected to the power generation assembly (3) and the absorption heat pump unit (2), the heat generated when the boiler unit (5) is operating being transported to the power generation assembly (3) and the absorption heat pump unit (2) respectively via the steam turbine unit (6), and the power generation assembly (3) achieving variable load by the mechanical heat pump unit (1) when the clutch mechanism (4) is in communication, characterized in that the boiler peak shift heat supply system.

2. The boiler peak shift heat supply system according to claim 1, characterized in that the steam turbine unit (6) and the absorption heat pump unit (2) are connected via a plurality of extraction circuits (61), and one of the extraction circuits (61) is provided with an adjustable intermediate pressure composite control valve (613).

3. The boiler peak shift heat supply system according to claim 2, characterized in that the extraction circuit (61) includes a plurality of extraction branch lines (611) and extraction main lines (612), one of the extraction branch lines (611) is provided with a check valve (6111) and an electric gate valve (6112), all of the extraction branch lines (611) are connected to the extraction main lines (612), and the extraction main lines (612) are connected to the absorption heat pump unit (2).

4. The steam turbine unit (6) includes a high-pressure cylinder (62), an intermediate-pressure cylinder (63), and a low-pressure cylinder (64) connected in order, and each of the high-pressure cylinder (62), the intermediate-pressure cylinder (63), and the low-pressure cylinder (64) includes a plurality of extraction heating assemblies (65), The extraction heating assembly (65) includes an extraction stage group (651) and a heater (652), all of which are arranged sequentially in the axial direction of the steam turbine unit (6). The boiler peak shift heat supply system according to claim 1, characterized in that a reheater (66) is provided between the high-pressure cylinder (62) and the intermediate-pressure cylinder (63), and two adjacent groups of extraction stages (651) are connected via the reheater (66).

5. The intermediate-pressure cylinder (63) includes two extraction heating assemblies (65), the two adjacent extraction heating assemblies (65) are connected via an intermediate-pressure reflux assembly (67), the intermediate-pressure reflux assembly (67) includes, in sequence, an intermediate-pressure reflux extraction stage group (671), a deaerator (672), and a feedwater pump group, the intermediate-pressure reflux extraction stage group (671) is coaxially arranged with the extraction stage group (651) of the two adjacent extraction heating assemblies (65), the deaerator (672) is connected to the heater (652) of the downstream intermediate-pressure cylinder (63), and the feedwater pump group is connected to the heater (652) of the upstream intermediate-pressure cylinder (63). and / or, the boiler peak shift heat supply system according to claim 4, wherein the low-pressure cylinder (64) includes two extraction heating assemblies (65) and a final stage extraction assembly (68) located downstream of the two extraction heating assemblies (65), the final stage extraction assembly (68) includes a final stage extraction stage group (681), an air-cooled condenser (682), and a condensate pump (683) connected in sequence, the final stage extraction stage group (681) being coaxially arranged with the extraction stage group (651) of the low-pressure cylinder (64), and the air-cooled condenser (682) being connected to the heater (652) of the adjacent low-pressure cylinder (64) via the condensate pump (683).

6. The boiler peak shift heat supply system according to claim 5, characterized in that the intermediate pressure reflux extraction stage group (671) and the air-cooled condenser (682) are connected via a small steam turbine (675), and a portion of the working fluid in the intermediate pressure reflux extraction stage group (671) flows into the small steam turbine (675) to drive the feedwater pump group.

7. The boiler peak shift heat supply system according to claim 6, characterized in that an electric valve (676) is provided between the small steam turbine (675) and the intermediate pressure reflux extraction stage group (671).

8. The steam turbine unit (6) further includes a mixing pipeline (69), the mixing pipeline (69) located between two adjacent heaters (652), and / or the mixing pipeline (69) located between adjacent heaters (652) and the deaerator (672), and / or the mixing pipeline (69) located between adjacent heaters (652) and the air-cooled condenser (682), The boiler peak shift heat supply system according to any one of claims 5 to 7, characterized in that the heat-exchanged working fluid in the heater (652) located downstream can be mixed by the mixing pipeline (69) with the unheat-exchanged working fluid in any one of the heater (652), the deaerator (672), and the air-cooled condenser (682) located upstream.

9. The boiler peak shift heat supply system according to claim 1, characterized in that the clutch mechanism (4) is an electromagnetic clutch.

10. The steps include acquiring the load status of the boiler peak shift heat supply system, An operating method for operating a boiler peak shift heat supply system according to any one of claims 1 to 9, comprising the step of disconnecting the connection between the power generation assembly (3) and the mechanical heat pump unit (1) when the boiler peak shift heat supply system is in a low load state.

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