Peak and frequency regulation refrigerating system of thermal power generating unit

Abstract

The embodiment of the invention provides a thermal power generating unit peak and frequency modulation refrigerating system which is characterized in that a main steam outlet of a coal-fired boiler is communicated with a steam inlet of a high-pressure cylinder, a steam outlet of the high-pressure cylinder is communicated with a hot resteam inlet of the coal-fired boiler, and a hot resteam outlet of the coal-fired boiler is communicated with a steam inlet of an intermediate-pressure cylinder; a steam outlet of the medium-pressure cylinder is communicated with a steam inlet of the low-pressure cylinder; the high-pressure cylinder, the medium-pressure cylinder, the low-pressure cylinder and the generator are sequentially connected through a steam turbine generator unit main shaft, the generator is further connected to a main transformer and a station transformer, the main transformer is used for supplying power to a power grid, and the station transformer is used for supplying power to a refrigerating device; the refrigerating device is connected to the ice maker, and the ice maker is used for receiving the ice-making raw materials and releasing heat of the ice-making raw materials to the refrigerating device to achieve ice making. According to the embodiment, the peak and frequency regulation range of the thermal power generating unit can be effectively widened, stable and safe operation of a boiler and a steam turbine of the unit is guaranteed, and the service life of the boiler and the steam turbine is prolonged.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the technical field of thermal power generation, and specifically relate to a peak-shaving and frequency-regulating refrigeration system for a thermal power unit. Background Art

[0002] Building a new power system with new energy as the main body is a necessary way to achieve energy transformation and "dual carbon" goals. However, with the rapid growth of new energy installed capacity, the power system faces the dual dilemma of a sharp increase in peak-shaving and frequency-regulation demand, which has accelerated the continuous expansion of the gap in demand for flexible resources, resulting in insufficient new energy absorption capacity of the power system. On the one hand, new energy sources such as wind power and photovoltaics have anti-peaking characteristics, which greatly increases the peak-shaving pressure of the power system. On the other hand, the low inertia characteristics of new energy units and the uncertainty and volatility of output have brought huge challenges to the frequency regulation of the power system. In order to meet the above challenges, thermal power units, as the supporting power source of the power system, must also make corresponding adjustments. Summary of the invention

[0003] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a peak-shaving and frequency-regulating refrigeration system for a thermal power unit.

[0004] The embodiment of the present disclosure provides a peak-shaving and frequency-regulating refrigeration system for a thermal power unit, the system comprising a coal-fired boiler, a high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a generator, a main transformer, a plant transformer, a refrigeration device and an ice maker;

[0005] The main steam outlet of the coal-fired boiler is communicated with the steam inlet of the high-pressure cylinder, the steam outlet of the high-pressure cylinder is communicated with the hot re-steam inlet of the coal-fired boiler, the hot re-steam outlet of the coal-fired boiler is communicated with the steam inlet of the intermediate-pressure cylinder, and the steam outlet of the intermediate-pressure cylinder is communicated with the steam inlet of the low-pressure cylinder;

[0006] The high-pressure cylinder, the medium-pressure cylinder, the low-pressure cylinder and the generator are connected in sequence through the main shaft of the steam turbine generator set. The generator is also connected to the main transformer and the plant transformer respectively. The main transformer is used to supply power to the power grid, and the plant transformer is used to supply power to the refrigeration device. The refrigeration device is connected to the ice maker, and the ice maker is used to receive ice-making raw materials and release the heat of the ice-making raw materials to the refrigeration device to achieve ice making.

[0007] Optionally, the steam outlet of the intermediate pressure cylinder is also connected to the heat source inlet of the refrigeration device.

[0008] Optionally, the system further comprises an auxiliary steam header;

[0009] The auxiliary steam header is used to supply steam to the refrigeration device.

[0010] Optionally, the generator is connected to the main transformer and the plant transformer via a medium-voltage conductor, the main transformer is connected to the power grid via a high-voltage conductor, and the plant transformer is connected to the refrigeration device via a low-voltage conductor.

[0011] Optionally, the system further comprises a raw material storage container and a pressurizer;

[0012] The raw material storage container is connected to the ice maker, and the pressurizer is arranged between the raw material storage container and the ice maker, and is used to transport the ice-making raw materials in the raw material storage container to the ice maker.

[0013] Optionally, the raw material storage container is configured as a desalted water tank, and the pressurizer is configured as a water feed pump.

[0014] Optionally, the raw material storage container is configured as a carbon dioxide gas cylinder, and the pressurizer is configured as a compressor.

[0015] Optionally, the refrigeration device includes an evaporator, and the evaporator absorbs heat from the inside of the ice maker by evaporation, so that the working medium in the ice maker becomes solid.

[0016] Optionally, the system further comprises a transport device;

[0017] The transport equipment is used to receive the finished ice in the ice maker and transport the finished ice to the user.

[0018] The peak-shaving and frequency-regulating refrigeration system of the thermal power unit disclosed in the embodiment of the present invention can reduce the online power consumption of the thermal power unit by increasing the power used by the refrigeration device without changing the original boiler operating load when the unit needs to reduce the load for peak-shaving and frequency-regulation; when the unit needs to increase the load, the thermal power unit can increase the online power consumption by reducing the power used by the refrigeration device without changing the original boiler operating load; it has a good energy-saving effect. It can also make the load change of the thermal power unit not be affected by the minimum stable combustion load of the coal-fired boiler, increase the peak-shaving and frequency-regulating range of the thermal power unit, ensure the stable and safe operation of the unit's boiler and steam turbine, and increase the service life of the boiler and steam turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a schematic structural diagram of a peak-shaving and frequency-regulating refrigeration system for a thermal power unit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0021] like Figure 1As shown, a peak-shaving and frequency-regulating refrigeration system 100 for a thermal power unit is provided, and the system 100 includes a coal-fired boiler 110, a high-pressure cylinder 120, an intermediate-pressure cylinder 130, a low-pressure cylinder 140, a generator 150, a main transformer 160, a plant transformer 170, a refrigeration device 180, and an ice maker 190. The main steam outlet of the coal-fired boiler 110 is communicated with the steam inlet of the high-pressure cylinder 120, the steam outlet of the high-pressure cylinder 120 is communicated with the hot re-steam inlet of the coal-fired boiler 110, the hot re-steam outlet of the coal-fired boiler 110 is communicated with the steam inlet of the intermediate-pressure cylinder 130, and the steam outlet of the intermediate-pressure cylinder 130 is communicated with the steam inlet of the low-pressure cylinder 140.

[0022] The high pressure cylinder 120, the medium pressure cylinder 130, the low pressure cylinder 140 and the generator 150 are connected in sequence through the main shaft 200 of the steam turbine generator set. The generator 150 is also connected to the main transformer 160 and the plant transformer 170 respectively. The main transformer 160 is used to supply power to the power grid, and the plant transformer 170 is used to supply power to the refrigeration device 180. The refrigeration device 180 is connected to the ice maker 190, and the ice maker 190 is used to receive ice-making raw materials and release the heat of the ice-making raw materials to the refrigeration device 180 to achieve ice making.

[0023] Specifically, Figure 1 As shown, the main steam of the coal-fired boiler 110 enters the high-pressure cylinder 120 to do work, the exhaust steam of the high-pressure cylinder 120 returns to the coal-fired boiler 110 and enters the medium-pressure cylinder 130 to do work after being heated again, and the exhaust steam of the medium-pressure cylinder 130 enters the low-pressure cylinder 140 to do work. The high-pressure cylinder 120, the medium-pressure cylinder 130, the low-pressure cylinder 140 and the generator 150 are connected by the same shaft, that is, the main shaft 200 of the steam turbine generator set. The low-pressure cylinder 140 works to drive the generator 150 to generate electricity, and the electricity generated by the generator 150 is divided into the main transformer 160 and the plant transformer 170. One of the paths is stepped up by the main transformer 160 and enters the power grid to supply power to the power grid to realize external power supply. The other path is stepped down by the plant transformer 170 and carries the plant power load. The power supply of the refrigeration device 180 is provided by this path so as to work. The ice-making raw materials in the ice-making machine 190 release heat to the refrigeration device 180 in the ice-making machine 190, and the ice-making raw materials themselves become solid to realize ice-making.

[0024] The embodiment of the present disclosure uses the plant transformer of the thermal power plant to increase or decrease the amount of electricity generated by the generator to achieve the purpose of reducing or increasing the amount of electricity connected to the grid, and uses the refrigeration device as a flexible load for precise regulation to achieve the purpose of optimizing the peak and frequency regulation characteristics of the thermal power unit. In addition, the refrigeration device is directly connected to the plant transformer of the thermal power unit, and the remaining capacity of the plant transformer is used to carry the compressor load. The system is simple and can reduce the investment in new transformers.

[0025] Furthermore, the steam outlet of the intermediate pressure cylinder 130 is also connected to the heat source inlet of the refrigeration device 180. In addition to entering the low pressure cylinder 130 to perform work, the steam of the intermediate pressure cylinder 130 also enters the refrigeration device 180 to drive the refrigeration device 180 to work.

[0026] It should be noted that the refrigeration device 180 can be an absorption refrigeration device or an electric refrigeration device. When the refrigeration type is absorption refrigeration, the heat source is the exhaust steam of the intermediate pressure cylinder 130, thereby driving the refrigeration device to work. When the refrigeration type is electric refrigeration, the power supply is provided by the surplus capacity of the plant transformer 170, thereby driving the refrigeration device to work.

[0027] The peak-shaving and frequency-regulating refrigeration system of the thermal power unit of the embodiment of the present disclosure configures a refrigeration device around the thermal power unit. When the unit needs to reduce the load for peak-shaving and frequency-regulation, the thermal power unit can reduce the online power by increasing the power used by the refrigeration device without changing the original boiler operating load. When the unit needs to increase the load, the thermal power unit can increase the online power without changing the original boiler operating load, and the online power can be increased by reducing the power used by the refrigeration device, which has a good energy-saving effect. In addition, the load change of the thermal power unit can be unaffected by the minimum stable combustion load of the coal-fired boiler, the peak-shaving and frequency-regulating range of the thermal power unit can be increased, the stable and safe operation of the boiler and steam turbine of the unit can be guaranteed, and the service life of the boiler and steam turbine can be increased.

[0028] For example, Figure 1 As shown, the system 100 further includes an auxiliary steam header 300. The auxiliary steam header 300 is used to supply steam to the refrigeration device 180.

[0029] Specifically, Figure 1 As shown, in addition to the exhaust steam from the intermediate pressure cylinder 130, the heat source of the refrigeration system 180 may also include an auxiliary steam header 300, through which steam is supplied to the refrigeration device 180. Using the exhaust steam from the intermediate pressure cylinder or the steam from the auxiliary steam header as a heat source to drive the refrigeration device to work can reduce the grid-connected power of the steam turbine generator set during the peak-shaving period, thereby also achieving the purpose of peak-shaving.

[0030] When the unit needs to reduce the load for peak and frequency regulation, the unit can reduce the amount of online electricity by increasing the steam supply to the refrigeration device or the power transformer for plant use without changing the original boiler operating load. When the unit needs to increase the load, the unit can increase the amount of online electricity by reducing the steam supply to the refrigeration device or the power transformer for plant use without changing the original boiler operating load. The controllable refrigeration device can completely replace the regulating valve of the unit, which has a good peak and frequency regulation effect.

[0031] For example, Figure 1As shown, the system 100 further includes a raw material storage container 191 and a pressurizer 192. The raw material storage container 191 is connected to the ice maker 190, and the pressurizer 192 is disposed between the raw material storage container 191 and the ice maker 190, and is used to transport the ice-making raw material in the raw material storage container 191 to the ice maker 190.

[0032] Specifically, Figure 1 As shown, the raw material storage container 192 stores ice-making raw materials, which are transported to the ice-making machine 190 through the pressurizer 192 and release heat to the refrigeration device 180 in the ice-making machine 190, so that the ice-making raw materials themselves become solid.

[0033] As a specific example, Figure 1 As shown, the raw material storage container 191 can be set as a desalted water tank, and the pressurizer 192 is correspondingly set as a water supply pump. At this time, the ice maker 190 can make food-grade ice cubes, and the desalted water enters the ice maker 190 to release heat and become ice cubes. The embodiment of the present disclosure uses the existing desalted water system of the thermal power plant as a water source to make ice cubes for external supply. The water source is sufficient, and only a set of water supply pumps and pipelines need to be added after the desalted water tank. The system is simple and reliable, and is very suitable for application scenarios in thermal power plants. As another specific example, the raw material storage container 191 can also be set as a carbon dioxide gas cylinder, and the pressurizer 192 is correspondingly set as a compressor. At this time, the ice maker 190 can make dry ice, and carbon dioxide directly changes from gas to solid dry ice after entering the ice maker 190.

[0034] Furthermore, the refrigeration device 180 includes an evaporator, which is a component of the refrigeration device 180 for realizing external refrigeration. The evaporator absorbs heat from the inside of the ice maker 190 by evaporation, so that the working medium in the ice maker 190 becomes solid.

[0035] With the rapid development of communication technology and the widespread promotion of the electricity spot trading market, the refrigeration system's ability to control internal load resources has been continuously enhanced. The refrigeration system can not only respond to real-time electricity prices in the spot market, but also participate in the auxiliary service market by using the demand response capability of flexible loads. By implementing refrigeration during the peak-shaving and frequency-regulating low-electricity-price periods throughout the day, it helps to improve the peak-shaving and frequency-regulating response capabilities of thermal power plants, improve the overall energy utilization rate of power plants, and optimize the power supply structure of the power grid. The produced dry ice or food-grade ice can also be supplied to the outside, which has significant economic benefits.

[0036] When the thermal power unit receives a dispatching instruction from the power grid to reduce the load for peak load regulation and frequency modulation, for the electric refrigeration device 180, the power supplied by the plant transformer 170 to the refrigeration device 180 is increased to increase the refrigeration capacity of the refrigeration device 180. At the same time, the supply of desalted water or carbon dioxide is increased to increase the output of ice or dry ice. When the output of the generator 150 consumed by the refrigeration device 180 increases, the power supply (grid-connected power) generated by the generator set is reduced, thereby realizing the peak load regulation and frequency modulation function of the thermal power unit.

[0037] For the absorption refrigeration device 180, the steam supplied to the refrigeration device 180 by the auxiliary steam header 300 and the exhaust steam of the intermediate pressure cylinder 130 is increased, and the heat of the driving heat source is increased to increase the refrigeration capacity of the refrigeration device 180. At the same time, the supply of desalted water or carbon dioxide is increased to increase the output of ice or dry ice. When the steam consumed by the refrigeration device 180 increases, the power generated by the generator set decreases, thereby realizing the peak and frequency regulation function of the thermal power unit.

[0038] When the thermal power unit receives a grid dispatch instruction to increase the amount of electricity connected to the grid, the electric refrigeration device 180 is provided with less electricity from the plant transformer 170, so as to reduce the refrigeration capacity of the refrigeration device 180. At the same time, the supply of desalted water or carbon dioxide is reduced to reduce the production of ice or dry ice. When the amount of electricity generated by the generator 150 consumed by the refrigeration device 180 decreases, the amount of electricity (connected to the grid) generated by the generator set increases.

[0039] For the absorption refrigeration device 180, the steam supplied to the refrigeration device 180 by the auxiliary steam header 300 and the exhaust steam of the intermediate pressure cylinder 130 is reduced, and the heat of the driving heat source is reduced so as to reduce the refrigeration capacity of the refrigeration device 180. At the same time, the supply of desalted water or carbon dioxide is reduced to reduce the production of ice or dry ice. When the steam consumed by the refrigeration device 180 is reduced, the power generated by the generator set increases, and the power connected to the grid also increases synchronously.

[0040] The installed capacity of new energy sources has been greatly increased. Under the current power structure on the power generation side, in order to prevent a large number of wind and solar power abandonment, thermal power units must give up capacity channels to reduce loads. During periods when wind and solar power stations generate little or no electricity, it is necessary to quickly increase the operating load of thermal power units, which is bound to greatly improve the operating flexibility of thermal power units. In order to increase the peak-shaving range of thermal power units and prevent the load changes of thermal power units from being affected by the minimum stable combustion load of power station boilers, thermal power units need to be equipped with peak-shaving and frequency-regulating systems to adjust the mismatch between energy supply and demand in time, space and intensity. The peak-shaving and frequency-regulating refrigeration system of the thermal power unit of the embodiment of the present disclosure uses the existing desalted water or carbon dioxide gas in the thermal power plant as raw materials, and increases or decreases the amount of electricity connected to the grid by adjusting the energy load of the newly added refrigeration device to achieve the purpose of peak-shaving and frequency-regulating the thermal power unit. The raw materials for ice making, power supply for refrigeration and heat source resources are sufficient, the cost is low, and the operation is safe and stable. It is very suitable for the peak-shaving and frequency-regulating transformation of existing thermal power units.

[0041] For example, Figure 1 As shown, the generator 150 is connected to the main transformer 160 and the plant transformer 170 via a medium voltage conductor 400 , the main transformer 160 is connected to the power grid via a high voltage conductor 500 , and the plant transformer 170 is connected to the refrigeration device 180 via a low voltage conductor 600 .

[0042] Specifically, Figure 1 As shown, the electricity generated by the generator 150 is distributed to the main transformer 160 and the plant transformer 170 by the medium voltage conductor 400. One of the paths is stepped up by the main transformer 160 and then enters the power grid through the high voltage conductor 500 to realize external power supply. The other path is stepped down by the plant transformer 170 and then carries the plant power load through the low voltage conductor 600. The power supply of the refrigeration device 180 (electric refrigeration) is provided by this path.

[0043] For example, Figure 1 As shown, the system 100 further includes a transport device 700. The transport device 700 is used to receive the finished ice in the ice making machine 190 and transport the finished ice to a user 800.

[0044] Specifically, Figure 1As shown, the finished ice produced by the ice maker 190 enters a transport device 700, such as a transport vehicle. The transport vehicle then transports the finished ice to the user 800, completing the entire process of external refrigeration supply. The transport vehicle needs to be recycled, and the number of transport vehicles in the embodiment of the present disclosure is determined by the amount of ice or dry ice produced. The use of transport vehicles to achieve mobile cooling reduces the land occupation and cost of building ice storage in power plants. User 800 can be a supermarket, a fresh food store, a bar, a coffee shop, etc. For example, using desalted water as a raw material to make ice cubes can reach an edible grade and be supplied to food-grade users such as bars, coffee shops, milk tea shops, supermarkets, and fresh food. Dry ice produced using carbon dioxide gas as a raw material can be supplied to the outside for refrigeration, preservation, and the like.

[0045] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A peak-shaving and frequency-regulating refrigeration system for a thermal power unit, characterized in that: The system includes a coal-fired boiler, a high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a generator, a main transformer, a plant transformer, a refrigeration unit and an ice machine; The main steam outlet of the coal-fired boiler is communicated with the steam inlet of the high-pressure cylinder, the steam outlet of the high-pressure cylinder is communicated with the hot re-steam inlet of the coal-fired boiler, the hot re-steam outlet of the coal-fired boiler is communicated with the steam inlet of the intermediate-pressure cylinder, and the steam outlet of the intermediate-pressure cylinder is communicated with the steam inlet of the low-pressure cylinder; The high-pressure cylinder, the medium-pressure cylinder, the low-pressure cylinder and the generator are connected in sequence through the main shaft of the steam turbine generator set. The generator is also connected to the main transformer and the plant transformer respectively. The main transformer is used to supply power to the power grid, and the plant transformer is used to supply power to the refrigeration device. The refrigeration device is connected to the ice maker, and the ice maker is used to receive ice-making raw materials and release the heat of the ice-making raw materials to the refrigeration device to achieve ice making.

2. The peak-shaving and frequency-regulating refrigeration system for thermal power units according to claim 1, characterized in that: The steam outlet of the intermediate pressure cylinder is also in communication with the heat source inlet of the refrigeration device.

3. The peak-shaving and frequency-regulating refrigeration system for thermal power units according to claim 2 is characterized in that: The system also includes an auxiliary steam header; The auxiliary steam header is used to supply steam to the refrigeration device.

4. The peak-shaving and frequency-regulating refrigeration system for thermal power units according to any one of claims 1 to 3, characterized in that: The generator is connected to the main transformer and the plant transformer via a medium-voltage conductor, the main transformer is connected to the power grid via a high-voltage conductor, and the plant transformer is connected to the refrigeration device via a low-voltage conductor.

5. The peak-shaving and frequency-regulating refrigeration system for thermal power units according to any one of claims 1 to 3, characterized in that: The system also includes a raw material storage container and a pressurizer; The raw material storage container is connected to the ice maker, and the pressurizer is arranged between the raw material storage container and the ice maker, and is used to transport the ice-making raw materials in the raw material storage container to the ice maker.

6. The peak-shaving and frequency-regulating refrigeration system for thermal power generation units according to claim 5, characterized in that: The raw material storage container is configured as a desalted water tank, and the pressurizer is configured as a water supply pump.

7. The peak-shaving and frequency-regulating refrigeration system for thermal power generation units according to claim 5, characterized in that: The raw material storage container is configured as a carbon dioxide gas cylinder, and the pressurizer is configured as a compressor.

8. The peak-shaving and frequency-regulating refrigeration system for thermal power units according to any one of claims 1 to 3, characterized in that: The refrigeration device comprises an evaporator, and the evaporator absorbs heat from the inside of the ice maker by evaporation, so that the working medium in the ice maker changes into a solid state.

9. The peak-shaving and frequency-regulating refrigeration system for thermal power units according to any one of claims 1 to 3, characterized in that: The system also includes a transport device; The transport equipment is used to receive the finished ice in the ice maker and transport the finished ice to the user.

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