Peak shaving system of light-coal-storage multi-energy complementary power station and operation method

Abstract

The invention discloses a light-coal-storage multi-energy complementary power station peak shaving system and an operation method. The system comprises a coal-fired power generating unit, an electric heating pump, a heat storage tank, a cold storage tank, a heat exchanger, a photovoltaic power generation system, a power controller and the like. Redundant electric quantity of a power grid is consumed through a heat pump and converted into heat energy and cold energy in two qualities to be stored respectively in a power off-peak period, meanwhile, an oil tank is adopted to store solar light and heat, part of condensed water of a steam turbine is heated through heat storage cascade in a power peak period, and meanwhile, cold storage release is matched with a high-vacuum-degree condenser to cool a photovoltaic power generation system. And generating capacity of a power station unit and a photovoltaic system is improved. Power storage is replaced by cold storage and heat storage, flexible and efficient peak regulation of the coal-fired power station and the photovoltaic power station is achieved, and the new energy power consumption level can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical fields of photovoltaic power generation, energy storage, solar-thermal conversion, and power station peak shaving, and particularly relates to a solar-coal-energy storage multi-energy complementary power station peak shaving system and an operation method thereof. Background Art

[0002] New energy power generation such as solar energy has strong time-varying and reverse peak-shaving characteristics, bringing huge challenges to the safe peak shaving of the power grid. The efficiency of solar photovoltaic power generation is relatively low, and a part of the light energy is converted into heat energy to increase its working temperature. The efficiency of the solar photovoltaic power generation system decreases with the increase of the working temperature, which further leads to the deterioration of its photoelectric conversion efficiency. Coal-fired power stations are the main body of flexible power sources in China, and deep peak shaving operation of coal-fired units will become a normal state in the next few years. Improving the operation flexibility of coal-fired units to promote the consumption of new energy power is a key technology in the energy and power industry. At present, the following technical problems exist in the peak shaving flexibility of conventional coal-fired units: (1) The energy comprehensive utilization level of peak shaving methods such as electric boilers and bypass main steam is low. In order to expand the operation range of the unit and improve the peak shaving capacity, the thermal economy of the unit will be further sacrificed.

[0003] (2) The existing coal-fired unit peak shaving technologies have problems such as inflexible parameter adjustment and inflexible selection of heat sources and cold sources. Conventional unit peak shaving technologies face practical problems such as low energy utilization efficiency and small peak shaving depth. It is difficult to achieve coordinated improvement among key performances such as the thermal economy of the unit, the flexible operation range, and the load change rate.

[0004] Conventional photovoltaic power generation systems have the practical problem of low photoelectric conversion efficiency, especially the further deterioration of the photoelectric conversion efficiency at higher ambient temperatures.

[0005] Therefore, the present invention proposes a solar-coal-energy storage multi-energy complementary power station peak shaving system and an operation method thereof. Through the integration of solar thermal energy, heat pumps, coal-fired power generation, and photovoltaic power generation, the complementary conversion between multiple energy forms of heat, electricity, and cold is realized. Through the integration of the heat storage and cold storage systems, the cross-time and space utilization of multiple energy flows is realized. The cooling of the photovoltaic system and the exhaust of the steam turbine are released by the cold storage to achieve the coordinated improvement of the power generation efficiency of photovoltaic power generation and coal-fired power generation. Using cold storage and heat storage instead of electricity storage realizes the coordinated improvement of the system economy and flexibility. Summary of the Invention

[0006] In order to solve the problems existing in the above-mentioned prior art, by replacing electricity storage with cold and heat storage to promote the coordinated improvement of peak shaving efficiency and flexibility, with the expectation of significantly improving the consumption level of new energy power, the present invention provides a peak shaving system and operation method for a photovoltaic-thermal-coal-storage multi-energy complementary power station. The system includes a coal-fired power generation unit, an electric heat pump, a heat storage tank, a cold storage tank, a heat exchanger, a photovoltaic power generation system, a power controller, etc.; during the low electricity period, the redundant electricity in the power grid is consumed by the heat pump and converted into heat and cold energy of two qualities for storage respectively. At the same time, an oil tank is used to store solar thermal energy. During the high electricity period, the heat storage is used to heat part of the condensate water of the steam turbine in a cascaded manner, and at the same time, the cold storage is released to match the condenser with a high vacuum degree and cool the photovoltaic power generation system, so as to increase the power generation of the power station unit and the photovoltaic system. The present invention replaces electricity storage with cold and heat storage, realizes flexible and efficient peak shaving of coal-fired power stations and photovoltaic power stations, and can significantly improve the consumption level of new energy power.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A peak shaving system for a photovoltaic - coal - energy storage multi - energy complementary power station, comprising a low - pressure cylinder 01 of a steam turbine, a shell side of a condenser 02, a condensate pump 03, a regulating valve Ding B4, a cold fluid side of an eighth - stage low - pressure heater 04, a cold fluid side of a seventh - stage low - pressure heater 05, and a feed water pipeline of a sixth - stage low - pressure heater, which are connected in sequence; the extraction pipelines of the seventh and eighth stages of the steam turbine are respectively connected to the steam inlet pipeline of the seventh - stage low - pressure heater 05 and the steam inlet pipeline of the eighth - stage low - pressure heater 04; the sixth - stage drain pipeline is connected in sequence to the drain side of the seventh - stage low - pressure heater 05, the drain side of the eighth - stage low - pressure heater 04, and the shell side of the condenser 02; the outlet pipeline of the condensate pump 03 is also connected in sequence to a regulating valve Bing B3, a cold fluid side of a heat exchanger A 07, a water side of an oil - water heat exchanger A 06, a regulating valve Jia B1, and the feed water pipeline of the sixth - stage low - pressure heater; the pipeline between the cold fluid side of the heat exchanger A 07 and the water side of the oil - water heat exchanger A 06 is also connected in sequence to a regulating valve Yi B2, a variable - frequency water pump P4, and the outlet pipeline of the cold fluid side of the eighth - stage low - pressure heater 04; a cold oil tank 15 is connected in sequence to a variable - frequency oil pump Yi P3, an oil valve Ding A4, an oil valve Bing A3, a solar collector 16, an oil pump P1, an oil valve Jia A1, a variable - frequency oil pump Jia P2, and a hot oil tank 14; the pipeline between the oil valve Jia A1 and the oil pump P1 is also connected in sequence to an oil valve Yi A2, an oil side of an oil - water heat exchanger Yi 17, an oil valve Wu A5, an oil valve Ding A4, and a variable - frequency oil pump Yi P3; the pipeline between the oil side of the oil - water heat exchanger Yi 17 and the oil valve Yi A2 is also connected in sequence to an oil valve Ji A6, an oil side of an oil - water heat exchanger A 06, an oil valve Ding A4, and a variable - frequency oil pump Yi P3; the outlet pipeline of a normal - temperature water tank 12 is connected in sequence to a water pump Jia P6, a condenser of an electro - heat pump 18, a conversion valve Yi C2, a water side of an oil - water heat exchanger Yi 17, and an inlet of a hot water tank 13; the outlet pipeline of the normal - temperature water tank 12 is connected in sequence to a water pump Jia P6, an evaporator of the electro - heat pump 18, a conversion valve Bing C3, and an inlet of a cold water tank 11; the outlet pipeline of the hot water tank 13 is connected in sequence to a water pump Yi P5, a conversion valve Jia C1, a hot fluid side of a heat exchanger A 07, and an inlet of the normal - temperature water tank 12; the outlet pipeline of the cold water tank 11 is connected in sequence to a water pump Bing P7, a conversion valve Wu C5, a cold fluid side of a heat exchanger Yi 09, and an inlet of the normal - temperature water tank 12; the outlet of the tube side of the condenser 02 is connected in sequence to a cooling tower 08, a hot fluid side of a heat exchanger Yi 09, and an inlet of the tube side of the condenser 02; the outlet pipeline of the cold water tank 11 is connected in sequence to a water pump Bing P7, a conversion valve Ding C4, a cooling pipeline of a photovoltaic power generation system 10, and an inlet of the normal - temperature water tank 12; the low - pressure cylinder 01 of the steam turbine is connected to a coal - fired power station generator 19 through a mechanical shaft; the coal - fired power station generator 19 and the photovoltaic power generation system 10 are respectively connected to two inlets of a power controller 20 through circuits; two outlets of the power controller 20 are respectively connected to a power grid and the electro - heat pump 18 through circuits.

[0008] The peak shaving system of the optical-coal-energy storage multi-energy complementary power station operates in the following manner during the low electricity consumption period: close the oil valves A6, regulating valves B1, B2, B3, switching valves C1, C4, C5, variable frequency water pump P4, water pump P5, and water pump P7; adjust the opening of regulating valve B4 to 100%; connect the circuit of the electrothermal pump 18 through the power controller 20 and adjust the power of the electrothermal pump 18 so that the electrical load output by the power controller 20 to the power grid meets the power grid demand. At the same time, open and adjust water pump P6, switching valve C2, and switching valve C3 so that the working medium at the inlet of the cold water tank 11 and the temperature at the water side inlet of the oil-water heat exchanger 17 are maintained at the set values; if the low electricity consumption period is during the day: open and adjust the opening of oil valves A1, A2, A3, A4, and A5, open and adjust the flow rate of oil pump P1, open and adjust the flow rate and flow direction of variable frequency oil pump P2 and variable frequency oil pump P3 so that the heat transfer oil flows out from the cold oil tank 15 and the oil side outlet of the oil-water heat exchanger 17, and after being heated by the solar collector 16, flows into the hot oil tank 14 and the oil side inlet of the oil-water heat exchanger 17, and at the same time, maintain the temperature of the working medium flowing into the hot oil tank 14 and the temperature of the working medium at the water side outlet of the oil-water heat exchanger 17 at the set values; if the low electricity consumption period is at night: close oil valve A3 and oil pump P1, open and adjust the opening of oil valves A1, A2, A4, and A5, open and adjust the flow rate and flow direction of variable frequency oil pump P2 and variable frequency oil pump P3 so that the heat transfer oil flows out from the hot oil tank 14 and flows into the cold oil tank 15 through the oil side of the oil-water heat exchanger 17, and at the same time, maintain the temperature of the working medium at the water side outlet of the oil-water heat exchanger 17 at the set values.

[0009] The described peak shaving system for a photovoltaic - coal - energy storage multi - energy complementary power station operates in the following manner during the peak electricity consumption period in the daytime: Shut down pump A P6, switching valve B C2, switching valve C C3, and oil valve E A5; Disconnect the circuit of the electro - heat pump 18 through the power controller 20; Turn on pump C P7 and adjust its flow rate, open and adjust the opening degrees of switching valve D C4 and switching valve E C5, so that the photovoltaic power generation system 10 maintains the optimal working temperature, and at the same time, the outlet temperature of the hot fluid of heat exchanger B 09 matches the vacuum degree of the condenser 02 during the peak electricity period; Turn on the variable - frequency pump P4 and adjust its flow rate and flow direction, open and adjust the control valves A B1, control valve B B2, control valve C B3, and control valve D B4, so that the proportions of the heated condensate water in heat exchanger A 07 and the oil - water heat exchanger A 06 are respectively maintained at the set values; Open and adjust the opening degree of switching valve A C1, turn on pump B P5 and adjust its flow rate, so that the outlet temperature of the cold fluid of heat exchanger A 07 is maintained at the set value; Open the oil valve F A6 and maintain its opening degree at 100%; Open and adjust the opening degrees of oil valve A A1, oil valve B A2, oil valve C A3, and oil valve D A4, turn on the oil pump P1, variable - frequency oil pump A P2, and variable - frequency oil pump B P3, and adjust the flow rate of the oil pump P1 and the flow direction and flow rate of the variable - frequency oil pump A P2 and variable - frequency oil pump B P3 according to the light intensity, so that the outlet temperature of the water side of the oil - water heat exchanger A 06 is maintained at the set value.

[0010] The described peak shaving system for a photovoltaic - coal - energy storage multi - energy complementary power station operates in the following manner during the peak electricity consumption period at night: Shut down pump A P6, switching valve B C2, switching valve C C3, and oil valve E A5; Disconnect the circuit of the electro - heat pump 18 through the power controller 20; Close the switching valve D C4, turn on pump C P7 and adjust its flow rate, open and adjust the opening degree of switching valve E C5, so that the outlet temperature of the hot fluid of heat exchanger B 09 matches the vacuum degree of the condenser 02 during the peak electricity period; Turn on the variable - frequency pump P4 and adjust its flow rate and flow direction, open and adjust the control valves A B1, control valve B B2, control valve C B3, and control valve D B4, so that the proportions of the heated condensate water in heat exchanger A 07 and the oil - water heat exchanger A 06 are respectively maintained at the set values; Open and adjust the opening degree of switching valve A C1, turn on pump B P5 and adjust its flow rate, so that the outlet temperature of the cold fluid of heat exchanger A 07 is maintained at the set value; Open the oil valve F A6 and maintain its opening degree at 100%; Close the oil valve C A3 and the oil pump P1; Open and adjust the opening degrees of oil valve A A1, oil valve B A2, and oil valve D A4, open and adjust the flow rate and flow direction of the variable - frequency oil pump A P2 and variable - frequency oil pump B P3, so that the heat - conducting oil flows out from the hot oil tank 14 and flows into the cold oil tank 15 through the oil side of the oil - water heat exchanger A 06, and at the same time, the outlet temperature of the water side of the oil - water heat exchanger A 06 is maintained at the set value.

[0011] Compared with the prior art, the present invention has the following advantages: (1)During the low electricity consumption period, an electrothermal pump is used to consume the redundant electricity in the power grid, achieving low-irreversibility conversion and storage of electricity-thermal cooling, and greatly improving the load reduction capacity of the unit while ensuring energy efficiency.

[0012] (2)Heat storage and cold storage are adopted to achieve cross-time and space storage and utilization of energy, improving the energy efficiency level of the system.

[0013] (3)During the high electricity consumption period, the heat stored in the heat storage is released in a cascaded manner to heat the condensate water, the cold stored is released to match the increase in the vacuum degree of the condenser, and the cold stored is released to cool the photovoltaic power generation system to improve the photoelectric conversion efficiency, so as to improve the load increase capacity of the system by multiple measures.

[0014] (4)Through the reasonable matching of the operation method and the system configuration, the present invention improves the consumption level of new energy electricity such as solar energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a peak shaving system and an operation method for a light-coal-storage multi-energy complementary power station according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0017] In order to achieve the efficient and flexible coupling of energy storage technology, heat pump technology, solar photovoltaic power generation, solar thermal utilization and peak shaving technology of coal-fired power stations, a light-coal-storage multi-energy complementary power station peak shaving system according to the present invention is as Figure 1As shown in the figure, the system includes a low-pressure cylinder 01 of a steam turbine, the shell side of a condenser 02, a condensate pump 03, a regulating valve Ding B4, the cold fluid side of an eighth-stage low-pressure heater 04, the cold fluid side of a seventh-stage low-pressure heater 05, and a feedwater pipe of a sixth-stage low-pressure heater, which are connected in sequence; the extraction pipes of the seventh and eighth stages of the steam turbine are respectively connected to the steam inlet pipe of the seventh-stage low-pressure heater 05 and the steam inlet pipe of the eighth-stage low-pressure heater 04; the sixth-stage drain pipe is connected in sequence to the drain side of the seventh-stage low-pressure heater 05, the drain side of the eighth-stage low-pressure heater 04, and the shell side of the condenser 02; the outlet pipe of the condensate pump 03 is also connected in sequence to a regulating valve Bing B3, the cold fluid side of a heat exchanger A 07, the water side of an oil-water heat exchanger A 06, a regulating valve Jia B1, and the feedwater pipe of the sixth-stage low-pressure heater; the pipe between the cold fluid side of the heat exchanger A 07 and the water side of the oil-water heat exchanger A 06 is also connected in sequence to a regulating valve Yi B2, a variable-frequency water pump P4, and the outlet pipe of the cold fluid side of the eighth-stage low-pressure heater 04; a cold oil tank 15 is connected in sequence to a variable-frequency oil pump B P3, an oil valve Ding A4, an oil valve Bing A3, a solar collector 16, an oil pump P1, an oil valve Jia A1, a variable-frequency oil pump A P2, and a hot oil tank 14; the pipe between the oil valve Jia A1 and the oil pump P1 is also connected in sequence to an oil valve Yi A2, the oil side of an oil-water heat exchanger B 17, an oil valve Wu A5, an oil valve Ding A4, and a variable-frequency oil pump B P3; the pipe between the oil side of the oil-water heat exchanger B 17 and the oil valve Yi A2 is also connected in sequence to an oil valve Ji A6, the oil side of an oil-water heat exchanger A 06, an oil valve Ding A4, and a variable-frequency oil pump B P3; the outlet pipe of a normal-temperature water tank 12 is connected in sequence to a water pump A P6, the condenser of an electrothermal pump 18, a conversion valve Yi C2, the water side of an oil-water heat exchanger B 17, and the inlet of a hot water tank 13; the outlet pipe of the normal-temperature water tank 12 is connected in sequence to a water pump A P6, the evaporator of the electrothermal pump 18, a conversion valve Bing C3, and the inlet of a cold water tank 11; the outlet pipe of the hot water tank 13 is connected in sequence to a water pump B P5, a conversion valve Jia C1, the hot fluid side of a heat exchanger A 07, and the inlet of the normal-temperature water tank 12; the outlet pipe of the cold water tank 11 is connected in sequence to a water pump C P7, a conversion valve Wu C5, the cold fluid side of a heat exchanger B 09, and the inlet of the normal-temperature water tank 12; the outlet of the tube side of the condenser 02 is connected in sequence to a cooling tower 08, the hot fluid side of a heat exchanger B 09, and the inlet of the tube side of the condenser 02; the outlet pipe of the cold water tank 11 is connected in sequence to a water pump C P7, a conversion valve Ding C4, the cooling pipe of a photovoltaic power generation system 10, and the inlet of the normal-temperature water tank 12; the low-pressure cylinder 01 of the steam turbine is connected to a coal-fired power station generator 19 through a mechanical shaft; the coal-fired power station generator 19 and the photovoltaic power generation system 10 are respectively connected to the two inlets of a power controller 20 through circuits; the two outlets of the power controller 20 are respectively connected to the power grid and the electrothermal pump 18 through circuits. Through the above system design, the low-irreversibility conversion and cascade storage of the annual surplus electricity can be realized, and at the same time, the rapid load increase and wide-load range operation during the peak power period can be realized, thereby greatly improving the system flexibility and the comprehensive energy utilization efficiency, and promoting the consumption of solar power.

[0018] In order to develop the peak shaving system of the optical-coal-energy storage multi-energy complementary power station more scientifically and effectively, it operates in the following manner during the low electricity consumption period: close the oil valves A6, regulating valves B1, B2, B3, conversion valves C1, C4, C5, variable frequency water pump P4, water pump P5, and water pump P7, so that the oil-water heat exchanger 06, heat exchanger 07, and heat exchanger 09 do not work; adjust the opening of the regulating valve B4 to 100%, at this time all the condensate water is heated by the steam turbine regenerative system; turn on the circuit of the electrothermal pump 18 through the power controller 20 and adjust the power of the electrothermal pump 18 so that the electric load output by the power controller 20 to the power grid meets the power grid demand. At the same time, open and adjust the water pump P6, conversion valves C2, and C3, so that the working medium at the inlet of the cold water tank 11 and the temperature at the water side inlet of the oil-water heat exchanger 17 are maintained at the set value, thus completing the conversion of electricity-thermal cooling; if the low electricity consumption period is during the day: open and adjust the opening of the oil valves A1, A2, A3, A4, A5, open and adjust the flow rate of the oil pump P1, open and adjust the flow rate and flow direction of the variable frequency oil pump P2 and variable frequency oil pump P3, so that the heat transfer oil flows out from the cold oil tank 15 and the oil side outlet of the oil-water heat exchanger 17, and after being heated by the solar collector 16, flows into the hot oil tank 14 and the oil side inlet of the oil-water heat exchanger 17. At the same time, make the temperature of the working medium flowing into the hot oil tank 14 and the temperature of the working medium at the water side outlet of the oil-water heat exchanger 17 maintain at the set value. Through this process, a large amount of solar heat during the day can be stored, and the cascade heating of condensate water can be realized; if the low electricity consumption period is at night: close the oil valve A3 and the oil pump P1, so that the solar collector 16 and its pipeline do not work, open and adjust the opening of the oil valves A1, A2, A4, A5, open and adjust the flow rate and flow direction of the variable frequency oil pump P2 and variable frequency oil pump P3, so that the heat transfer oil flows out from the hot oil tank 14 and flows into the cold oil tank 15 through the oil side of the oil-water heat exchanger 17. At the same time, make the temperature of the working medium at the water side outlet of the oil-water heat exchanger 17 maintain at the set value. Through the above operation method, low-irreversibility electricity-thermal cooling conversion of the system can be realized during the low electricity period, and heat storage and cold storage are used instead of electricity storage, so as to achieve the purpose of promoting the consumption of new energy power with heat storage and cold storage.

[0019] In order to develop the peak shaving system of the light-coal-energy storage multi-energy complementary power station more scientifically and effectively, it operates according to the following method during the peak electricity consumption period in the daytime: Close water pump P6, switching valve C2, switching valve C3, and oil valve A5. Disconnect the circuit of the electrothermal pump 18 through the power controller 20, so that the electrothermal pump 18 and the oil-water heat exchanger 17 do not work; Open water pump P7 and adjust its flow rate, open and adjust the opening degrees of switching valve C4 and switching valve C5, so that the photovoltaic power generation system 10 maintains the optimal working temperature, thereby increasing its power generation. At the same time, the outlet temperature of the hot fluid of heat exchanger 9 matches the vacuum degree of the condenser 02 during the peak electricity period, thereby increasing the power generation of the coal-fired generating unit; Open the variable-frequency water pump P4 and adjust its flow rate and flow direction, open and adjust the control valves B1, B2, B3, and B4, so that the proportions of the condensed water heated in heat exchanger 7 and oil-water heat exchanger 6 are respectively maintained at the set values, achieving the purpose of releasing stored heat to assist in heating the condensed water, reducing the extraction steam volume of the steam turbine, and increasing the power generation of the unit; Open and adjust the opening degree of switching valve C1, open water pump P5 and adjust its flow rate, so that the outlet temperature of the cold fluid of heat exchanger 7 is maintained at the set value; Open oil valve A6 and maintain its opening degree at 100%; Open and adjust the opening degrees of oil valves A1, A2, A3, and A4, open oil pump P1, variable-frequency oil pump P2, and variable-frequency oil pump P3, and adjust the flow rate of oil pump P1 and the flow direction and flow rate of variable-frequency oil pumps P2 and P3 according to the light intensity, so that the outlet temperature of the water side of oil-water heat exchanger 6 is maintained at the set value. Through the above operation method, the system can quickly increase the load during the peak electricity period in the daytime, and broaden the upper limit of the system operation range in the form of releasing stored heat and stored cold, increase the power generation of the photovoltaic system, realize the flexible and efficient coordinated operation of the system, and thus achieve the purpose of promoting the consumption of new energy electricity with stored heat and stored cold.

[0020] In order to develop the peak shaving system of the optical-coal-energy storage multi-energy complementary power station more scientifically and effectively, it operates according to the following method during the peak electricity consumption period at night: Close water pump P6, switching valve C2, switching valve C3, and oil valve A5. Disconnect the circuit of the electrothermal pump 18 through the power controller 20, so that the electrothermal pump 18 and the oil-water heat exchanger 17 do not work. Close switching valve C4 to make the pipeline of the cooling photovoltaic power generation system 10 not work. Open water pump P7 and adjust its flow rate. Open and adjust the opening degree of switching valve C5 so that the outlet temperature of the hot fluid of heat exchanger 09 matches the vacuum degree of the condenser 02 during the peak electricity period, in order to increase the power generation of the coal-fired power generation system. Open the variable-frequency water pump P4 and adjust its flow rate and direction. Open and adjust control valves B1, B2, B3, and B4 so that the proportion of the heated condensate in heat exchanger 07 and oil-water heat exchanger 06 is maintained at the established value respectively. Open and adjust the opening degree of switching valve C1. Open water pump P5 and adjust its flow rate so that the outlet temperature of the cold fluid of heat exchanger 07 is maintained at the established value. Open oil valve A6 and maintain its opening degree at 100%. Close oil valve A3 and oil pump P1 to make the solar collector 16 and its pipeline not work. Open and adjust the opening degrees of oil valves A1, A2, and A4. Open and adjust the flow rate and direction of variable-frequency oil pump P2 and variable-frequency oil pump P3 so that the heat-conducting oil flows out of the hot oil tank 14 and flows into the cold oil tank 15 through the oil side of the oil-water heat exchanger 06, and at the same time make the outlet temperature of the water side of the oil-water heat exchanger 06 maintained at the established value, so as to achieve the purpose of auxiliary heating of condensate and increasing the power generation of the coal-fired unit. Through the above operation method, the system can quickly increase the load during the peak electricity period at night, and broaden the upper limit of the system operation range in the way of releasing heat storage and cold storage, realizing the flexible and efficient coordinated operation of the system, so as to achieve the purpose of promoting the consumption of new energy power with heat storage and cold storage.

Claims

1. A solar-coal-storage multi-energy complementary power station peak-shaving system, characterized by: The invention comprises a steam turbine low-pressure cylinder (01), a condenser (02) shell side, a condensate pump (03), a control valve D (B4), an eighth-stage low-pressure heater (04) cold fluid side, a seventh-stage low-pressure heater (05) cold fluid side, and a sixth-stage low-pressure heater feed water pipe which are connected in sequence; the seventh and eighth-stage steam extraction pipes of the steam turbine are respectively connected to the steam inlet pipe of the seventh-stage low-pressure heater (05) and the steam inlet pipe of the eighth-stage low-pressure heater (04); the sixth-stage drain pipe is connected in sequence to the drain side of the seventh-stage low-pressure heater (05), the drain side of the eighth-stage low-pressure heater (04), and the shell side of the condenser (02); the outlet pipe of the condensate pump (03) is also connected in sequence to the control valve C (B3), the cold fluid side of the heat exchanger A (07), the oil-water heat exchanger A (06) water side, control valve A (B1), and the sixth-stage low-pressure heater water supply pipeline; the pipeline between the cold fluid side of heat exchanger A (07) and the water side of oil-water heat exchanger A (06) is also connected in sequence to control valve B (B2), variable frequency water pump (P4), and the outlet pipeline of the cold fluid side of the eighth-stage low-pressure heater (04); the cold oil tank (15) is connected in sequence to variable frequency oil pump B (P3), oil valve D (A4), oil valve C (A3), solar collector (16), oil pump (P1), oil valve A (A1), variable frequency oil pump A (P2), and hot oil tank (14); the pipeline between oil valve A (A1) and oil pump (P1) is also connected in sequence to oil valve B (A2), the oil side of oil-water heat exchanger B (17), oil valve E (A5), oil valve D (A4), and variable frequency The pipeline between the oil side of the oil-water heat exchanger B (17) and the oil valve B (A2) is also connected in sequence to the oil valve F (A6), the oil side of the oil-water heat exchanger A (06), the oil valve D (A4), and the variable frequency oil pump B (P3); the outlet pipeline of the normal temperature water tank (12) is connected in sequence to the water pump A (P6), the electric heat pump (18) condenser, the conversion valve B (C2), the water side of the oil-water heat exchanger B (17), and the inlet of the hot water tank (13); the outlet pipeline of the normal temperature water tank (12) is connected in sequence to the water pump A (P6), the electric heat pump (18) evaporator, the conversion valve C (C3), and the inlet of the cold water tank (11); the outlet pipeline of the hot water tank (13) is connected in sequence to the water pump B (P5), the conversion valve A (C1), the hot fluid side of the heat exchanger A (07), and the normal temperature water tank (12) inlet; the outlet pipe of the cold water tank (11) is connected in sequence to the water pump C (P7), the conversion valve E (C5), the cold fluid side of the heat exchanger B (09), and the inlet of the normal temperature water tank (12); the outlet of the condenser (02) is connected in sequence to the cooling tower (08), the hot fluid side of the heat exchanger B (09), and the inlet of the condenser (02); the outlet pipe of the cold water tank (11) is connected in sequence to the water pump C (P7), the conversion valve D (C4), the cooler pipe of the photovoltaic power generation system (10), and the inlet of the normal temperature water tank (12); the low-pressure cylinder (01) of the steam turbine is connected to the coal-fired power station generator (19) through a mechanical shaft; the coal-fired power station generator (19) and the photovoltaic power generation system (10) are connected to the A and B inlets of the power controller (20) through circuits, respectively;The two outlets A and B of the power controller (20) are connected to the power grid and the electric heat pump (18) respectively through circuits. ; 2. The method for operating the peak-shaving system of a photovoltaic-coal-storage multi-energy complementary power station during the low electricity consumption period as described in claim 1, characterized in that: Close the oil valve A6, the regulating valve A (B1), the regulating valve B (B2), the regulating valve C (B3), the switching valve A (C1), the switching valve D (C4), the switching valve E (C5), the variable frequency water pump (P4), the water pump B (P5), and the water pump C (P7); adjust the opening of the regulating valve D (B4) to 100%; connect the circuit of the electric heat pump (18) through the power controller (20) and adjust the power of the electric heat pump (18) so that the power controller (20) ) to the power grid to meet the power grid demand, and at the same time open and adjust the water pump A (P6), conversion valve B (C2), conversion valve C (C3), so that the inlet working medium of the cold water tank (11) and the water side inlet temperature of the oil-water heat exchanger B (17) are maintained at a predetermined value; if the power consumption is low during the day: open and adjust the opening of oil valve A (A1), oil valve B (A2), oil valve C (A3), oil valve D (A4), oil valve E (A5), open and adjust the oil pump (P1) The flow rate of variable frequency oil pump A (P2) and variable frequency oil pump B (P3) is opened and adjusted, so that the heat transfer oil flows out from the oil side outlet of the cold oil tank (15) and the oil-water heat exchanger B (17), and flows into the hot oil tank (14) and the oil side inlet of the oil-water heat exchanger B (17) after being heated by the solar collector (16). At the same time, the working fluid temperature flowing into the hot oil tank (14) and the working fluid temperature at the water side outlet of the oil-water heat exchanger B (17) are maintained at a predetermined value. If the electricity consumption is low during the off-peak period, At night: close the oil valve C (A3) and the oil pump (P1), open and adjust the opening of the oil valve A (A1), oil valve B (A2), oil valve D (A4), and oil valve E (A5), open and adjust the flow rate and flow direction of the variable frequency oil pump A (P2) and variable frequency oil pump B (P3), so that the heat transfer oil flows out from the hot oil tank (14) and flows into the cold oil tank (15) through the oil side of the oil-water heat exchanger B (17), and at the same time, the outlet working medium temperature of the water side of the oil-water heat exchanger B (17) is maintained at a predetermined value.

3. The method for operating the peak-shaving system of a photovoltaic-coal-storage multi-energy complementary power station during the peak period of daytime electricity consumption as described in claim 1, characterized in that: Turn off water pump A (P6), conversion valve B (C2), conversion valve C (C3), and oil valve E (A5); disconnect the circuit of the electric heat pump (18) through the power controller (20); turn on water pump C (P7) and adjust its flow rate, open and adjust the opening of conversion valve D (C4) and conversion valve E (C5), so that the photovoltaic power generation system (10) maintains the optimal operating temperature, and at the same time, the outlet temperature of the hot fluid of heat exchanger B (09) matches the vacuum degree of the condenser (02) during the peak power period; turn on the variable frequency water pump (P4) and adjust its flow rate and flow direction, open and adjust the control valve A (B1), control valve B (B2), control valve C (B3), and control valve D (B4), so that the heat exchanger A (07) and the oil The proportion of heated condensed water in water heat exchanger A (06) is maintained at a predetermined value; the opening of conversion valve A (C1) is opened and adjusted, and water pump B (P5) is opened to adjust its flow rate, so that the outlet temperature of the cold fluid of heat exchanger A (07) is maintained at a predetermined value; oil valve F (A6) is opened and maintained at 100%; the openings of oil valve A (A1), oil valve B (A2), oil valve C (A3), and oil valve D (A4) are opened and adjusted, and the oil pump (P1), variable frequency oil pump A (P2), and variable frequency oil pump B (P3) are opened, and the flow rate of oil pump (P1) and the flow direction and flow rate of variable frequency oil pump A (P2) and variable frequency oil pump B (P3) are adjusted according to the light intensity, so that the outlet temperature of the water side of oil-water heat exchanger A (06) is maintained at a predetermined value.

4. The method for operating the peak-shaving system of a photovoltaic-coal-storage multi-energy complementary power station during the peak period of electricity consumption at night as described in claim 1, characterized in that: Turn off water pump A (P6), conversion valve B (C2), conversion valve C (C3), and oil valve E (A5); disconnect the circuit of the electric heat pump (18) through the power controller (20); turn off conversion valve D (C4), turn on water pump C (P7) and adjust its flow rate, and turn on and adjust the opening of conversion valve E (C5) so that the outlet temperature of the hot fluid of heat exchanger B (09) matches the vacuum degree of condenser (02) during the peak power period; turn on the variable frequency water pump (P4) and adjust its flow rate and flow direction, and turn on and adjust control valve A (B1), control valve B (B2), control valve C (B3), and control valve D (B4) so ​​that the heated condenser in heat exchanger A (07) and oil-water heat exchanger A (06) is The ratio of water is maintained at a predetermined value; the conversion valve A (C1) is opened and adjusted in opening degree, and the water pump B (P5) is opened and adjusted in flow rate, so that the outlet temperature of the cold fluid of the heat exchanger A (07) is maintained at a predetermined value; the oil valve F (A6) is opened and maintained in opening degree 100%; the oil valve C (A3) and the oil pump (P1) are closed; the oil valve A (A1), the oil valve B (A2), and the oil valve D (A4) are opened and adjusted in opening degree, and the flow rate and flow direction of the variable frequency oil pump A (P2) and the variable frequency oil pump B (P3) are opened and adjusted, so that the heat transfer oil flows out from the hot oil tank (14) and flows into the cold oil tank (15) through the oil side of the oil-water heat exchanger A (06), and at the same time, the outlet temperature of the water side of the oil-water heat exchanger A (06) is maintained at a predetermined value.

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