Tank reversing operation system and method for compressed air energy storage spherical tank

Abstract

The invention discloses a compressed air energy storage spherical tank inversion operation system and method, and belongs to the technical field of energy storage, and the compressed air energy storage spherical tank inversion operation system comprises an energy storage system of a plurality of energy storage spherical tanks connected in parallel, a constant pressure system connected with the energy storage spherical tanks, and two wall temperature control devices connected with the energy storage system in parallel, the wall temperature control device comprises a low-temperature regulation and control device and a high-temperature regulation and control device, and a low-temperature water inlet main pipeline and a high-temperature water inlet main pipeline are connected with a plurality of energy storage spherical tanks of the energy storage system respectively in the flowing direction of high-temperature water and low-temperature water. A water outlet pipe of the energy storage spherical tank is connected with a low-temperature regulation and control device and a high-temperature regulation and control device through pipelines, the low-temperature regulation and control device is connected with a high-temperature water inlet pipe through a low-temperature mixed water bypass, and the high-temperature regulation and control device is connected with a low-temperature water inlet pipe through a high-temperature mixed water bypass. And the low-temperature regulating device and the high-temperature regulating device are simultaneously connected with the heat exchanger respectively.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage, and in particular relates to a compressed air energy storage spherical tank inverting operation system and an inverting operation method. Background Art

[0002] With the deepening of the "dual carbon" goals and the acceleration of the low-carbon transformation of electricity, the demand for new energy storage has grown rapidly, which has promoted the accelerated development of the new energy storage industry. The country supports the construction of energy storage high-tech industrialization bases, promotes the integrated development of production, learning, research and application, and continuously strengthens the new energy storage industry.

[0003] By the end of 2023, the total installed capacity of new energy storage projects that have been put into operation nationwide has reached 31.39 million kilowatts / 66.87 million kilowatt-hours, with an average storage time of 2.1 hours. In 2023, the newly installed capacity will be about 22.6 million kilowatts / 48.7 million kilowatt-hours, an increase of more than 260% from the end of 2022. There are 11 provinces (regions) in the country with an installed capacity of more than one million kilowatts.

[0004] Compressed air energy storage, as a major component of new energy storage, is an effective means to improve the regulation capacity of the power system and has the conditions for large-scale commercial application. With the development of technology, compressed air energy storage power stations have put forward higher requirements for efficiency. The heat exchange temperature is a key factor restricting the efficiency of compressed air energy storage power stations. Increasing the heat exchange temperature is conducive to improving the overall efficiency of the power station, thereby improving the economic efficiency of the power station operation. Compressed air energy storage power stations use water as the heat storage and exchange medium, with the lowest initial investment and operation and maintenance costs. When storing heat, it is necessary to pressurize the normal pressure water, so the storage tanks are all pressure storage tanks, and nitrogen is used for pressure stabilization. In order to reduce the cost of storage tanks and reduce the floor space, the heat storage system only has hot water spherical tanks to rotate and store high-temperature water and low-temperature water. The temperature of low-temperature water is between 50-80℃, and the temperature of high-temperature water is between 200-240℃. Due to the large temperature difference between low-temperature water and high-temperature water, the temperature change rate of the spherical tank exceeds 30℃ / min, which makes the spherical tank have huge thermal stress when rotating and storing low-temperature water and high-temperature water. After more than a dozen or even several times of charging and discharging heat, the spherical tank will be fatigued and damaged, and it is difficult to meet the use requirements; at the same time, due to the difference in density between high-temperature water and low-temperature water, the inverted tank system has a gas phase space of only 20%-30% of that of a conventional double-tank system, and the nitrogen pressure change range is 3-4 times that of a conventional system. The system pressure changes dramatically, and there is a risk of system overpressure and low-pressure vaporization. In view of the low cost and high safety of water media, how to control the temperature change rate of the spherical tank, reduce the thermal stress of the heat storage process, and maintain the pressure of the spherical tank has become a technical problem. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a compressed air energy storage spherical tank inverting operation system and method, which can control the temperature change rate of the spherical tank, ensure the safety and stability of the spherical tank during operation, reduce the fatigue loss of the spherical tank, reduce the secondary stress when the storage medium of the spherical tank changes from low-temperature water to high-temperature water and from high-temperature water to low-temperature water, increase the service life of the spherical tank, and reduce the mixed temperature loss of the heat storage system and the loss of the spherical tank constant pressure system during the operation of the spherical tank.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A compressed air energy storage spherical tank tank inversion operation system comprises an energy storage system of several parallel energy storage spherical tanks, a constant pressure system connected to the energy storage spherical tanks and two parallel wall temperature control devices connected to the energy storage system, wherein the wall temperature control device comprises a low-temperature control device and a high-temperature control device, and along the flow direction of high-temperature water and low-temperature water, a low-temperature water inlet main pipeline and a high-temperature water inlet main pipeline are respectively connected to several energy storage spherical tanks of the energy storage system, a water outlet pipe of the energy storage spherical tank is respectively connected to the low-temperature control device and the high-temperature control device through a pipeline, the low-temperature control device is connected to the high-temperature water inlet pipe through a low-temperature mixed temperature water bypass, the high-temperature control device is connected to the low-temperature water inlet pipe through a high-temperature mixed temperature water bypass, and the low-temperature control device and the high-temperature control device are respectively connected to a heat exchanger at the same time.

[0008] A further improvement of the technical solution of the present invention is that: the constant pressure system includes a constant pressure water tank, and the constant pressure pipe of the constant pressure water tank and the energy storage spherical tank are connected simultaneously through pipeline 1 and pipeline 2 with a constant pressure water pump. A flow meter, a regulating valve and a shut-off valve are arranged in series on pipeline 1, two branches are arranged in parallel on pipeline 2, and a constant pressure water pump is arranged on each branch. Each branch is provided with a shut-off valve on the left and right sides of the constant pressure water pump, respectively. Manual shut-off valves are arranged on both sides of the parallel branches of pipeline 2 to connect with the constant pressure water tank, and a flow meter and a shut-off valve ② are arranged to connect with the constant pressure pipe. Pipeline 1 is directly connected to the constant pressure pipe pipeline, and pipeline 1 is connected to the pipeline between the flow meter ⑥ and the shut-off valve ② of pipeline 2 through a pipeline.

[0009] A further improvement of the technical solution of the present invention is that: a filter screen and a check valve are respectively arranged on the left and right of the constant pressure water pump on each branch of the pipeline 2, and a shut-off valve① is arranged on the constant pressure pipe.

[0010] A further improvement of the technical solution of the present invention is that: the low-temperature control device includes three low-temperature control branches in parallel, one of which is provided with a shut-off valve, a regulating valve, a filter, a low-temperature heat medium water pump, a check valve, and a shut-off valve in sequence, and the other two low-temperature control branches are provided with a shut-off valve, a regulating valve, a filter, a low-temperature mixed temperature water pump, a check valve, and a shut-off valve in sequence; the high-temperature control device includes three high-temperature control branches in parallel, one of which is provided with a shut-off valve, a regulating valve, a filter, a high-temperature heat medium water pump, a check valve, and a shut-off valve in sequence, and the other two high-temperature control branches are provided with a shut-off valve, a regulating valve, a filter, a high-temperature mixed temperature water pump, a check valve, and a shut-off valve in sequence.

[0011] A further improvement of the technical solution of the present invention is that: the pipelines connecting the low temperature control device and the high temperature control device with the energy storage system are both provided with shut-off valves, and the pipeline connecting the low temperature control device with the low temperature mixed water bypass is provided with a flow meter. and shut-off valve, a flow meter is installed on the pipeline connecting the high temperature control device and the high temperature mixed water bypass and shut-off valves.

[0012] A further improvement of the technical solution of the present invention is that: along the water flow direction, relevant shut-off valves, flow meters and the like are sequentially arranged on the high-temperature mixed water bypass. and regulating valve The low-temperature mixed water bypass is equipped with relevant shut-off valves and flow meters in sequence. and regulating valve The connecting pipes between the energy storage system and the low-temperature control device, the low-temperature control device and the low-temperature mixed water bypass, and the connecting pipes between the low-temperature control device and the low-temperature mixed water bypass constitute a low-temperature control subsystem; the connecting pipes between the energy storage system and the high-temperature control device, the high-temperature control device and the high-temperature mixed water bypass, and the connecting pipes between the high-temperature control device and the high-temperature mixed water bypass constitute a high-temperature control subsystem.

[0013] A further improvement of the technical solution of the present invention is that the energy storage spherical tanks of the heat storage system include energy storage spherical tanks No. 1 to N, each energy storage spherical tank is provided with a water outlet pipe connected to the wall temperature control device, all water outlet pipes are provided with shut-off valves, each energy storage spherical tank is provided with a low-temperature water inlet branch pipe and a high-temperature water inlet branch pipe respectively connected to the low-temperature water inlet main pipe and the high-temperature water inlet main pipe, and shut-off valves are respectively provided on the low-temperature water inlet branch pipe and the high-temperature water inlet branch pipe, and the state of energy storage spherical tank No. 1 is always kept as storing low-temperature water or empty during an energy storage cycle, and the state of energy storage spherical tank No. N is kept as storing high-temperature water or empty, and the constant pressure system of the entire spherical tank heat storage system is arranged on energy storage spherical tank No. 1, a constant pressure pipe is arranged at the bottom of energy storage spherical tank No. 1, the constant pressure water tank is a normal pressure water tank, the constant pressure water pump is operated at power frequency, one is in operation and the other is in standby, and the manual shut-off valve is a normally open valve.

[0014] A method for stabilizing pressure of a compressed air energy storage spherical tank inverting operation system comprises the following steps:

[0015] During heat storage, when the pressure of the energy storage spherical tank is higher than P7, the constant pressure water discharge system is opened, and the regulating valve on pipeline 1 is adjusted to supply water from spherical tank No. 1 to the constant pressure water tank at a flow rate of Q4. At this time, the shut-off valve ② is closed, the two constant pressure water pumps are closed, and the shut-off valve ①, the shut-off valve on pipeline 1 and the regulating valve are opened. The pressure difference between the energy storage spherical tank and the constant pressure water tank is used to discharge water to the constant pressure water tank. By comparing the flow meter value on pipeline 1 with the fixed value Q4, the opening of the regulating valve on pipeline 1 is adjusted to keep the water discharge flow unchanged and maintain the spherical tank pressure within the normal operating range. When the spherical tank pressure reaches P8, the shut-off valve ① and the shut-off valve are closed, and the constant pressure water discharge system is closed. In the accident condition, when the spherical tank is still under pressure after the water is discharged at a flow rate of Q4 or is in the P7 state, the regulating valve on pipeline 1 is fully opened, and water is discharged to the constant pressure water tank at a flow rate of Q5. When the pressure drops to P8, the constant pressure water discharge system is closed.

[0016] During heat release, when the pressure of the energy storage tank is lower than P5, the constant pressure system is turned on. At this time, the shut-off valve ① and the shut-off valve ② are opened, a constant pressure water pump is turned on, and the other constant pressure water pump is turned off. The shut-off valve and the regulating valve on the pipeline 1 are closed. The flow rate of the opened constant pressure water pump is controlled by comparing the flow meter value on the pipeline 2 with the constant value Q1. The head of the constant pressure water pump is P6. The No. 1 energy storage tank is supplemented with high-pressure and low-temperature water through this constant pressure water pump to maintain the pressure of the energy storage tank within the normal range. When the pressure of the energy storage tank reaches P6, the constant pressure water pump is turned off first, and then the shut-off valve ① and the shut-off valve ② are closed to turn off the constant pressure system. In the accident condition, when the energy storage tank is supplied with water at the flow rate Q1, the pressure of the energy storage tank is still reduced or in the P5 state. At this time, another constant pressure water pump is turned on to supply water to the No. 1 energy storage tank at twice the flow rate of Q1. When the pressure rises to P6, the constant pressure system is turned off.

[0017]

[0018] Q 5 =n 7 Q 4

[0019]

[0020] P 2 =saturation pressure(T 2 )

[0021] P 0 =min(saturation pressure(T 2 +ΔT 3 ),n 4 ×saturation pressure(T 2 ))

[0022] P 1 =n 5 P 0

[0023] P 3 =min(saturation pressure(T 2 +ΔT 4 ),n 6 ×saturation pressure(T 2 ))

[0024] P 4 =P 1 -ΔP 9

[0025]

[0026] P 7 =P 4 -ΔP 10

[0027] P 8 =P 3 +ΔP 10

[0028] Q 1 : Constant pressure water pump flow, t / h;

[0029] Q 2 : High-temperature water flow rate when the compressed air energy storage system releases energy under design conditions, t / h;

[0030] Q 3 : Low-temperature water flow rate of compressed air energy storage system during energy storage under design conditions, t / h;

[0031] Q 4 : Constant pressure discharge flow, t / h;

[0032] Q 5 : Maximum flow rate of the regulating valve, t / h;

[0033] ρ 1 : Density of low temperature water, kg / m 3 ;

[0034] ρ 2 : High temperature water density, kg / m 3 ;

[0035] V 1 : Constant pressure water tank volume, m 3 ;

[0036] T 1: low temperature water temperature, K;

[0037] T 2 : high temperature water temperature, K;

[0038] ΔT 3 : Safety margin of spherical tank design temperature, °C, value 5-10, P 2 When the value is large, take a small value, P 2 When it is smaller, take the larger value;

[0039] ΔT 4 : Safety margin of spherical tank operating temperature, °C, value 3-5, P 2 When the value is large, take a small value, P 2 When it is smaller, take the larger value;

[0040] P 0 : Design pressure of spherical tank, MPa;

[0041] P 1 : Opening pressure of spherical tank safety valve, MPa;

[0042] P 2 : high temperature water saturation pressure, MPa;

[0043] P 3 : The lower limit of the constant pressure operation pressure of the spherical tank, MPa;

[0044] P 4 : Upper limit of constant pressure operation pressure of spherical tank, MPa;

[0045] P 5 : Opening pressure of constant pressure water supply of spherical tank, MPa;

[0046] P 6 : Ball tank constant pressure water supply closing pressure, MPa;

[0047] P 7 : Opening pressure of spherical tank constant pressure water discharge, MPa;

[0048] P 8 : Closing pressure of spherical tank constant pressure drain, MPa;

[0049] ΔP 9 : Safety margin of spherical tank operating pressure, MPa, value 0.05-0.1, P 2 When it is larger, it takes a larger value, P 2 When it is smaller, take the smaller value;

[0050] ΔP 10 : Spherical tank constant pressure safety margin, MPa, value 0.1-0.2, P 2 When it is larger, take a smaller value, P 2 When it is smaller, take the larger value;

[0051] n 1 : Constant pressure water supply flow temperature reduction coefficient, the value is 0.8-0.9;

[0052] n 2 : The temperature reduction coefficient of the constant pressure water tank is 0.7-0.8;

[0053] n 3 : Safety factor of constant pressure water tank capacity, including the change of low temperature water flow rate of heat storage system when ambient temperature changes, with a value of 1.2-1.3;

[0054] n 4 : Spherical tank pressure safety factor, value 1.25-1.5, P 2 When the value is large, take a small value, P 2 When it is smaller, take the larger value;

[0055] n 5 : Ball tank safety valve jump coefficient, value 0.8-0.95, P 0 When it is larger, it takes a larger value, P 2 When it is smaller, take a smaller value; n 6 : Spherical tank operating pressure safety factor, value 1.1-1.25, P 2 When the value is large, take a small value, P 2 Take a larger value when it is smaller; n 7 : Accidental discharge coefficient of spherical tank, value is 1.5-2, P 4 When the value is large, take a small value, P 2 When it is smaller, take the larger value;

[0056] t 1 : The compression storage time of a compressed air energy storage system within a storage and release cycle.

[0057] A method for reversing a compressed air energy storage spherical tank in a reversing operation system comprises the following steps:

[0058] When the heat storage is storing high-temperature water in the Nth spherical tank, the shut-off valve on the high-temperature water inlet branch of the Nth energy storage spherical tank and the shut-off valve on the outlet pipe of the N-1th energy storage spherical tank are opened, and the shut-off valves on the high-temperature water inlet branch and low-temperature water inlet branch of all other energy storage spherical tanks and the shut-off valves on the drain pipe are closed;

[0059] Close all shut-off valves of the high-temperature control subsystem, open all shut-off valves and regulating valves of the low-temperature control subsystem, as well as the low-temperature heat medium water pump and the low-temperature mixed temperature water pump. The low-temperature water passes through the low-temperature control device, goes to the low-temperature mixed temperature water bypass, and enters the heat exchanger for heat exchange. The low-temperature heat medium water pump is operated at a flow rate Q 3 Working, two low temperature mixed temperature water pumps with a total flow rate Q 5 Working, through flow meter and flow meter The flow value controls the flow of the low-temperature heat medium water pump and two low-temperature mixed temperature water pumps through the flow meter Control valve The opening degree changes hourly to achieve the low-temperature mixed water flow rate;

[0060] When the wall temperature rate v of the energy storage tank t1 Reach v 2 When the two low-temperature mixed temperature water pumps are turned off, the shut-off valve and regulating valve on the low-temperature mixed temperature water bypass are closed. At this time, the temperature rise rate and thermal stress of the spherical tank wall reach the allowable range of the energy storage spherical tank. Only the low-temperature heat medium water pump is operated to supply water to the energy storage spherical tank to meet the use requirements. When supplying high-temperature water to other energy storage spherical tanks, the outlet pipes and high-temperature water inlet pipes of different energy storage spherical tanks are switched. The rest of the working mode is the same as supplying high-temperature water to the Nth spherical tank. The design flow rates of the low-temperature heat medium water pump and the low-temperature mixed temperature water pump are both Q 6 ;

[0061] When releasing heat to store low-temperature water in the No. 1 energy storage tank, open the shut-off valve on the low-temperature water inlet branch of the first energy storage tank and the shut-off valve on the outlet pipe of the second energy storage tank, and close the shut-off valves on the high-temperature water inlet branch and low-temperature water inlet branch of all other energy storage tanks and the shut-off valves on the drain pipe;

[0062] Close all shut-off valves of the low-temperature control subsystem, open all shut-off valves and regulating valves of the high-temperature control subsystem, as well as the high-temperature heat medium water pump and the high-temperature mixed temperature water pump. The high-temperature water flows from the second energy storage spherical tank through the high-temperature control device, goes to the high-temperature mixed temperature water bypass, and enters the heat exchanger for heat exchange. The high-temperature heat medium water pump is at a flow rate Q 2 Working, two high temperature mixed temperature water pumps with a total flow rate Q 7 Working, through flow meter and flow meter The flow value controls the flow of the high-temperature heat medium water pump and two high-temperature mixed temperature water pumps through the flow meter Control valve The opening degree changes hour by hour to achieve high-temperature mixed water flow;

[0063] When the wall temperature rate v of the energy storage tank t3 Reach v 4 When the two high-temperature mixed temperature water pumps are turned off, the shut-off valve and regulating valve on the high-temperature mixed temperature water bypass are turned off. At this time, the cooling rate and thermal stress of the energy storage tank wall temperature reach the allowable range of the energy storage tank. Only the high-temperature heat medium water pump is operated to supply water to the energy storage tank to meet the use requirements. When supplying low-temperature water to other energy storage tanks, the outlet pipes and low-temperature inlet pipes of different energy storage tanks are switched. The rest of the working mode is the same as supplying high-temperature water to the No. 1 energy storage tank. The design flow rates of the high-temperature heat medium water pump and the high-temperature mixed temperature water pump are both Q 8 .

[0064]

[0065] m t0 =2πh t1 RΔm / 10 6

[0066] Q t1 =m t1 ×c 1

[0067] Q t2 =V t1 ×c 2 ×ρ t0

[0068]

[0069] V t0 : The remaining low-temperature water volume in the spherical tank at the previous moment, m 3 ;

[0070] V t1 : The remaining low-temperature water volume in the spherical tank at a certain time, m 3 ;

[0071] Q t1 : The heat required for unit temperature rise of the spherical tank at a certain moment, MJ / ℃;

[0072] Q t2 : The heat required for the unit temperature rise of the remaining heat medium water in the spherical tank at a certain moment, MJ / ℃;

[0073] v t1 : The rate of change of the spherical tank wall temperature at a certain moment, ℃ / min;

[0074] v 2 : The allowable rate of change of wall temperature when the spherical tank is heated, ℃ / min, with a value of 9-11;

[0075] c 1 : Specific heat capacity of spherical tank metal material, kJ / ;

[0076] c 2 : Specific heat capacity of low-temperature water in spherical tank, kJ / ;

[0077] c 3 : Specific heat capacity of high temperature water in spherical tank, kJ / ;

[0078] R: radius of spherical tank, m;

[0079] R t0 : radius of the liquid surface of the spherical tank at a certain moment, m;

[0080] Δm: spherical tank wall thickness, mm;

[0081] m t1: The mass of the part of the spherical tank in contact with the heat medium water at a certain moment, t;

[0082] ρ t0 : Density of heat medium water in the spherical tank at a certain moment, kg / m 3 ;

[0083] h t0 : The height of the liquid level in the spherical tank at the previous moment;

[0084] h t1 : Liquid level in the spherical tank at a certain moment;

[0085] Q 2 : High-temperature water flow rate when the compressed air energy storage system releases energy under design conditions, t / h;

[0086] Δt: spherical tank wall temperature rate calculation compensation, s, value is 10;

[0087] Q 3 : Low-temperature water flow rate of compressed air energy storage system during energy storage under design conditions, t / h;

[0088] Q 5 : Low-temperature mixed water flow rate at a certain moment, t / h;

[0089] Q 5max : Maximum flow rate of low-temperature mixed water, t / h;

[0090] T 1 : low temperature water temperature, K;

[0091] T 2 : high temperature water temperature, K;

[0092] T t1 : The temperature of low-temperature water in the spherical tank at a certain moment, K;

[0093] ΔT 4 : The design temperature safety margin of the spherical tank wall temperature control is ℃, and the value is 40-50.

[0094] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0095] The compressed air energy storage spherical tank inversion operation system and method provided in this application can control the temperature change rate of the spherical tank, ensure the safety and stability of the spherical tank during operation, reduce the fatigue loss of the spherical tank, reduce the secondary stress when the storage medium of the spherical tank changes from low-temperature water to high-temperature water and high-temperature water to low-temperature water, increase the service life of the spherical tank, and reduce the mixed temperature loss of the heat storage system and the loss of the spherical tank constant pressure system during the operation of the spherical tank. The promotion of this technology will greatly reduce the investment in the heat storage system and constant pressure system of large-scale compressed air energy storage power stations, improve the electrical efficiency of compressed energy storage power stations, and facilitate the large-scale promotion of compressed air energy storage power stations, helping to achieve the goals of "carbon peak and carbon neutrality".

[0096] The system of the present application eliminates the nitrogen preparation system. The entire nitrogen system of the original compressed air energy storage system is in a closed cycle. The system does not need nitrogen except for the initial filling nitrogen. The nitrogen required for the initial filling and the nitrogen leaked from the safety valve can be supplied by the nitrogen container. The compressed air energy storage power station does not need to be equipped with a nitrogen production system. The power station air compressor only needs to meet the instrument gas quality design, which simplifies the compressed air system and reduces investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 It is a schematic diagram of the compressed air energy storage spherical tank inversion operation system of the present application;

[0098] Figure 2 yes Figure 1 Enlarged view of the medium constant pressure system;

[0099] Figure 3 yes Figure 1 Enlarged view of the medium and low temperature mixed water bypass and the high temperature mixed water bypass;

[0100] Figure 4 yes Figure 1 An enlarged view of the middle wall temperature control device;

[0101] Among them, 1. Energy storage spherical tank, 2. Constant pressure water tank, 3. Low temperature control device, 4. High temperature control device, 5. Constant pressure water pump, 6. Check valve, 7. Manual shut-off valve, 8. Outlet pipe, 9. High temperature mixed temperature water bypass, 10. Low temperature mixed temperature water bypass, 11. Constant pressure pipe, 12. Filter, 13. Flow meter, 14. Shut-off valve, 15. Regulating valve, 16. Low temperature heat medium water pump, 17. Low temperature mixed temperature water pump, 18. High temperature heat medium water pump, 19. High temperature mixed temperature water pump;

[0102] For the convenience of description, some shut-off valves, regulating valves and flow meters are specifically marked, including: shut-off valve ①, shut-off valve ②, flow meter ⑥, flow meter Flow Meter Flow Meter Flow Meter Control valve Control valve It has the same function as the above-mentioned shut-off valve, flow meter and regulating valve. DETAILED DESCRIPTION

[0103] The present invention is further described in detail below in conjunction with embodiments:

[0104] like Figure 1As shown, a compressed air energy storage spherical tank tank inversion operation system includes an energy storage system of several parallel energy storage spherical tanks 1, a spherical tank constant pressure system connected to the energy storage spherical tanks 1, and two parallel wall temperature control devices connected to the energy storage system, the wall temperature control device includes a low-temperature control device 3 and a high-temperature control device 4, along the flow direction of high-temperature water and low-temperature water, the low-temperature water inlet main pipeline and the high-temperature water inlet main pipeline are respectively connected to the several energy storage spherical tanks 1 of the energy storage system, the outlet pipe 8 of the energy storage spherical tank 1 is respectively connected to the low-temperature control device 3 and the high-temperature control device 4 through pipelines, the low-temperature control device is connected to the high-temperature water inlet pipe through a low-temperature mixed water bypass 10, the high-temperature control device 4 is connected to the low-temperature water inlet pipe through a high-temperature mixed water bypass 9, and the low-temperature control device 3 and the high-temperature control device 4 are respectively connected to the heat exchanger at the same time.

[0105] The energy storage spherical tank 1 of the heat storage system includes energy storage spherical tanks No. 1 to N, each of which is provided with a water outlet pipe connected to the wall temperature control device, all water outlet pipes 8 are provided with shut-off valves, each of which is provided with a low-temperature water inlet branch pipe and a high-temperature water inlet branch pipe connected to the low-temperature water inlet main pipe and the high-temperature water inlet main pipe respectively, and shut-off valves 14 are provided on the low-temperature water inlet branch pipe and the high-temperature water inlet branch pipe respectively, and the state of energy storage spherical tank No. 1 is always kept as storing low-temperature water or empty during an energy storage cycle, and the state of energy storage spherical tank No. N is kept as storing high-temperature water or empty, and the constant pressure system of the entire spherical tank heat storage system is arranged in energy storage spherical tank No. 1, a constant pressure pipe 8 is arranged at the bottom of energy storage spherical tank No. 1, the constant pressure water tank is a normal pressure water tank, the constant pressure water pump is operated at power frequency, one is in operation and the other is in standby, and the manual shut-off valve is a normally open valve.

[0106] The spherical tank constant pressure system of the present application adopts low-temperature water for constant pressure. Only low-temperature water is involved in regulating the system pressure during water supply and water discharge. The constant pressure is only operated between energy storage spherical tank No. 1 and constant pressure water tank 2. The constant pressure water supply and constant pressure water discharge pipelines of the energy storage spherical tank adopt one interface. When storing heat, energy storage spherical tank No. 1 supplies water to constant pressure water tank 2. When releasing heat, constant pressure water tank 2 supplies water to energy storage spherical tank No. 1, which simplifies the constant pressure system.

[0107] like Figure 2 As shown, the spherical tank constant pressure system includes a constant pressure water tank 2, and the constant pressure water tank 2 and the constant pressure pipe of the energy storage spherical tank 1 are simultaneously connected through a pipeline 1 and a pipeline 2 provided with a constant pressure water pump. A flow meter 13, a regulating valve 15 and a shut-off valve 14 are arranged in series on the pipeline 1, and two branches are arranged in parallel on the pipeline 2, and a constant pressure water pump 5 is arranged on each branch. Each branch is provided with a shut-off valve 14 on the left and right sides of the constant pressure water pump 5, respectively. Manual shut-off valves 7 are respectively arranged on both sides of the parallel branches of the pipeline 2, which are connected to the constant pressure water tank 2, and a flow meter 13, a shut-off valve ② are connected to the constant pressure pipe 11, the pipeline 1 and the constant pressure pipe 11 are directly connected, and the pipeline 1 is connected to the pipeline between the flow meter ⑥ and the shut-off valve ② of the pipeline 2 through a pipeline.

[0108] On each branch of the pipeline 2, a filter screen 12 and a check valve 6 are respectively arranged on the left and right of the constant pressure water pump 5, and a shut-off valve ① is arranged on the constant pressure pipe 11.

[0109] In the present application, the constant pressure water pump 5 operates at industrial frequency, and two constant pressure water pumps 5 are provided to meet the requirements of daily and emergency working conditions. During daily operation, one constant pressure water pump operates at a constant flow rate, and during emergency working conditions, two constant pressure water pumps are put into operation. The constant pressure water pump always operates at a constant flow rate, saving the cost of the constant pressure water pump inverter while maintaining high-efficiency operation of the constant pressure water pump.

[0110] The spherical tank constant pressure system relies on the pressure difference between the spherical tank and the constant pressure water tank to release water. It does not require additional power or a constant pressure water release pump. The water release flow rate is adjusted by controlling the opening of the regulating valve to meet daily and emergency conditions.

[0111] The constant pressure water supply and constant pressure water discharge of the energy storage spherical tank share one pipe port, and the constant pressure water supply and constant pressure water discharge are realized through the operation of the valve switching system, which simplifies the constant pressure system. Flow meters are set on the discharge pipe and water supply pipe of the constant pressure system to adjust the system flow deviation through the difference between the actual flow and the set value flow, thereby reducing the occurrence of misoperation and accident conditions. The constant pressure water discharge flow and the constant pressure water supply flow are fixed values, and the valve opening is fixed. During operation, only the deviation between the flow and the set value needs to be considered. Except for accident conditions, there is no need to adjust the flow according to the working conditions.

[0112] like Figure 3 , 4 As shown, the low-temperature control device 3 includes three low-temperature control branches in parallel, one of which is provided with a shut-off valve 14, a regulating valve 15, a filter 12, a low-temperature heat medium water pump 16, a check valve 6, and a shut-off valve 14 in sequence, and the other two low-temperature control branches are provided with a shut-off valve 14, a regulating valve 15, a filter 12, a low-temperature mixed temperature water pump 17, a check valve 6, and a shut-off valve 14 in sequence; the high-temperature control device 4 includes three high-temperature control branches in parallel, one of which is provided with a shut-off valve 14, a regulating valve 15, a filter 12, a high-temperature heat medium water pump 18, a check valve 6, and a shut-off valve 14 in sequence, and the other two high-temperature control branches are provided with a shut-off valve 14, a regulating valve 15, a filter 12, a high-temperature mixed temperature water pump 19, a check valve 6, and a shut-off valve 14 in sequence.

[0113] The pipelines connecting the low temperature control device 3 and the high temperature control device 4 with the energy storage system are both provided with shut-off valves 14, and the pipeline connecting the low temperature control device 3 with the low temperature mixed water bypass 10 is provided with a flow meter. and shut-off valve, a flow meter is provided on the pipeline connecting the high temperature control device 4 and the high temperature mixed water bypass 9 and shut-off valves.

[0114] When storing and releasing heat, the energy storage tank is equipped with a low-temperature heat medium water pump, a low-temperature mixed temperature water pump, a high-temperature heat medium water pump, and a high-temperature mixed temperature water pump to avoid the large difference in the flow rates of low-temperature heat medium water and high-temperature heat medium water, which may cause difficulty in adjusting the control system, and to avoid the low-temperature heat medium water pump, the low-temperature mixed temperature water pump, the high-temperature heat medium water pump, and the high-temperature mixed temperature water pump from being damaged due to the large temperature difference between the low-temperature water and the high-temperature water.

[0115] Each energy storage spherical tank is only provided with one water outlet pipe 8. Both low-temperature water and high-temperature water enter the low-temperature heat medium water pump, the low-temperature mixed temperature water pump, the high-temperature heat medium water pump and the high-temperature mixed temperature water pump through the water outlet pipe 8. The operation of the pump group is switched by the shut-off valves arranged on the mother pipes before and after the pump group. Only the total shut-off valve in front of the pump group needs to withstand alternating thermal stress, and the rest of the equipment and valves are at a constant temperature.

[0116] Each energy storage spherical tank is equipped with a low-temperature water inlet branch pipe and a high-temperature water inlet branch pipe. Shut-off valves are respectively set on the low-temperature water inlet branch pipe and the high-temperature water inlet branch pipe. The low-temperature water inlet branch pipe and the high-temperature water inlet branch pipe work independently during heat storage and heat release to avoid direct impact of the low-temperature water inlet and the high-temperature water inlet on the inlet pipe when the heat storage and heat release conditions are switched. The low-temperature water inlet and the high-temperature water inlet are switched through the valve on the energy storage spherical tank inlet.

[0117] The low-temperature water inlet branch pipe and the high-temperature water inlet branch pipe are set above the highest liquid level at the top of the energy storage spherical tank, and do not contact the heat medium water in the heat storage spherical tank. The low-temperature water inlet and the high-temperature water inlet are first preheated / precooled with nitrogen before entering the bottom of the spherical tank, further reducing the temperature non-uniformity of the spherical tank and reducing the rate of change of the spherical tank wall temperature.

[0118] Along the water flow direction, the high temperature mixed water bypass 9 is provided with relevant shut-off valves, flow meters, and regulating valve The low-temperature mixed water bypass 10 is provided with a shut-off valve and a flow meter in sequence. and regulating valve The connecting pipes between the energy storage system and the low-temperature control device 3, the low-temperature control device 3 and the low-temperature mixed water bypass 10, and the connecting pipes between the low-temperature control device 3 and the low-temperature mixed water bypass 10 constitute a low-temperature control subsystem, and the connecting pipes between the energy storage system and the high-temperature control device 4, the high-temperature control device 4 and the high-temperature mixed water bypass 9, and the connecting pipes between the high-temperature control device 4 and the high-temperature mixed water bypass 9 constitute a high-temperature control subsystem.

[0119] The low-temperature mixed water bypass of the present application is provided with flow meters on the low-temperature jellyfish tube and the low-temperature mixed water bypass. When storing heat, the temperature of water entering the energy storage spherical tank is controlled by adjusting the low-temperature mixed water bypass flow and the low-temperature water flow to avoid the initial temperature of the high-temperature water entering the spherical tank being too high. The low-temperature mixed water bypass flow gradually decreases as the temperature of the spherical tank increases. The low-temperature mixed water bypass flow meter and the low-temperature jellyfish tube flow meter are used to reflect whether the opening of the regulating valve is appropriate.

[0120] The high-temperature mixed water bypass of the present application is provided with flow meters on the high-temperature jellyfish pipe and the high-temperature mixed water bypass. When storing heat, the temperature of water entering the spherical tank is controlled by adjusting the high-temperature mixed water bypass flow and the high-temperature water flow to avoid the initial temperature of the high-temperature water entering the spherical tank being too low. The high-temperature mixed water bypass flow gradually decreases as the temperature of the spherical tank decreases. The high-temperature mixed water bypass flow meter and the high-temperature jellyfish pipe flow meter are used to reflect whether the opening of the regulating valve is appropriate.

[0121] A pressure stabilization method for a compressed air energy storage spherical tank tank inversion operation system. During heat storage, when the pressure of the energy storage spherical tank is higher than P7, the constant pressure water discharge system is opened, and the regulating valve 15 on the pipeline 1 is adjusted to supply water from the spherical tank 1 to the constant pressure water tank 2 at a flow rate of Q4. At this time, the shut-off valve ② is closed, and the two constant pressure water pumps 5 are closed. The shut-off valve ①, the shut-off valve and the regulating valve on the pipeline 1 are opened, and the pressure difference between the energy storage spherical tank 1 and the constant pressure water tank 2 is used to discharge water to the constant pressure water tank 2. By comparing the flow counter on the pipeline 1, the pressure difference between the energy storage spherical tank 1 and the constant pressure water tank 2 is reduced. The opening of the regulating valve 15 on the pipeline 1 is adjusted by using the fixed value Q4 to keep the water discharge flow unchanged and maintain the pressure of the energy storage tank within the normal operating range. When the pressure of the energy storage tank reaches P8, the shut-off valve ① is closed to close the constant pressure water discharge system. In the accident condition, when the pressure of the energy storage tank is still increased or in the P7 state after the energy storage tank is discharged at the flow rate Q4, the regulating valve 15 on the pipeline 1 is fully opened, and water is discharged to the constant pressure water tank at the flow rate Q5. When the pressure drops to P8, the constant pressure water discharge system is closed.

[0122] During heat release, when the pressure of the energy storage tank is lower than P5, the constant pressure system is turned on. At this time, the shut-off valve ① and the shut-off valve ② are opened, a constant pressure water pump 5 is turned on, and another constant pressure water pump 5 is turned off. The shut-off valve 14 and the regulating valve 15 on the pipeline 1 are closed. The flow rate of the opened constant pressure water pump is controlled by comparing the flow meter value on the pipeline 2 with the constant value Q1. The head of the constant pressure water pump is P6. The No. 1 energy storage tank is supplemented with high-pressure and low-temperature water through this constant pressure water pump to maintain the pressure of the energy storage tank 1 within the normal range. When the pressure of the energy storage tank reaches P6, the constant pressure water pump is turned off first, and then the shut-off valve ① and the shut-off valve ② are closed to turn off the constant pressure system. In the accident condition, when the energy storage tank is supplied with water at the flow rate Q1, the pressure of the energy storage tank is still reduced or in the P5 state. At this time, another constant pressure water pump is turned on to supply water to the No. 1 energy storage tank at twice the flow rate of Q1. When the pressure rises to P6, the constant pressure system is turned off.

[0123]

[0124] Q 5 =n 7 Q 4

[0125]

[0126] P 2 =saturationpressure(T2 )

[0127] P 0 =min(saturation pressure(T 2 +ΔT 3 ),n 4 ×saturation pressure(T 2 ))

[0128] P 1 =n 5 P 0

[0129] P 3 =min(saturation pressure(T 2 +ΔT 4 ),n 6 ×saturation pressure(T 2 ))

[0130] P 4 =P 1 -ΔP 9

[0131]

[0132] P 7 =P 4 -ΔP 10

[0133] P 8 =P 3 +ΔP 10

[0134] Q 1 : Constant pressure water pump flow, t / h;

[0135] Q 2 : High-temperature water flow rate when the compressed air energy storage system releases energy under design conditions, t / h;

[0136] Q 3 : Low-temperature water flow rate of compressed air energy storage system during energy storage under design conditions, t / h;

[0137] Q 4 : Constant pressure water discharge flow, t / h;

[0138] Q 5 : Maximum flow rate of the regulating valve, t / h;

[0139] ρ 1 : Density of low temperature water, kg / m 3 ;

[0140] ρ 2 : High temperature water density, kg / m 3 ;

[0141] V 1 : Constant pressure water tank volume, m 3 ;

[0142] T 1 : low temperature water temperature, K;

[0143] T 2 : high temperature water temperature, K;

[0144] ΔT 3 : Safety margin of spherical tank design temperature, °C, value 5-10, P 2 When the value is large, take a small value, P 2 When it is smaller, take the larger value;

[0145] ΔT 4 : Safety margin of spherical tank operating temperature, °C, value 3-5, P 2 When the value is large, take a small value, P 2 When it is smaller, take the larger value;

[0146] P 0 : Design pressure of spherical tank, MPa;

[0147] P 1 : Opening pressure of spherical tank safety valve, MPa;

[0148] P 2 : High temperature water saturation pressure, MPa;

[0149] P 3 : Lower limit of constant pressure operation pressure of spherical tank, MPa;

[0150] P 4 : Upper limit of constant pressure operation pressure of spherical tank, MPa;

[0151] P 5 : Opening pressure of constant pressure water supply of spherical tank, MPa;

[0152] P 6 : Ball tank constant pressure water supply closing pressure, MPa;

[0153] P 7 : Opening pressure of spherical tank constant pressure water discharge, MPa;

[0154] P 8 : The closing pressure of the spherical tank constant pressure drain, MPa;

[0155] ΔP 9 : Safety margin of spherical tank operating pressure, MPa, value 0.05-0.1, P 2When it is larger, it takes a larger value, P 2 When it is smaller, take the smaller value;

[0156] ΔP 10 : Spherical tank constant pressure safety margin, MPa, value 0.1-0.2, P 2 When it is larger, take a smaller value, P 2 When it is smaller, take the larger value;

[0157] n 1 : Constant pressure water supply flow temperature reduction coefficient, the value is 0.8-0.9;

[0158] n 2 : The temperature reduction coefficient of the constant pressure water tank is 0.7-0.8;

[0159] n 3 : Safety factor of constant pressure water tank capacity, including the change of low temperature water flow rate of heat storage system when ambient temperature changes, with a value of 1.2-1.3;

[0160] n 4 : Spherical tank pressure safety factor, value 1.25-1.5, P 2 When it is larger, take a smaller value, P 2 When it is smaller, take the larger value;

[0161] n 5 : Ball tank safety valve jump coefficient, value 0.8-0.95, P 0 When it is larger, it takes a larger value, P 2 When it is smaller, take a smaller value; n 6 : Spherical tank operating pressure safety factor, value 1.1-1.25, P 2 When it is larger, take a smaller value, P 2 Take a larger value when it is smaller; n 7 : Accidental discharge coefficient of spherical tank, value is 1.5-2, P 4 When it is larger, take a smaller value, P 2 When it is smaller, take the larger value;

[0162] t 1 : The compression storage time of a compressed air energy storage system within a storage and release cycle.

[0163] A method for unloading a compressed air energy storage spherical tank unloading operation system. When storing high-temperature water in an N-th spherical tank, the shut-off valve on the high-temperature water inlet branch of the N-th energy storage spherical tank and the shut-off valve on the outlet pipe of the N-1-th energy storage spherical tank are opened, and the shut-off valves on the high-temperature water inlet branch and the low-temperature water inlet branch of all other energy storage spherical tanks and the shut-off valves on the drain pipe are closed; all the shut-off valves of the high-temperature control subsystem are closed, and all the shut-off valves and regulating valves of the low-temperature control subsystem as well as the low-temperature heat medium water pump 16 and the low-temperature mixed temperature water pump 17 are opened. The low-temperature water passes through the low-temperature control device, goes to the low-temperature mixed temperature water bypass, and enters the heat exchanger for heat exchange. The low-temperature heat medium water pump 16 is operated at a flow rate Q 3 Working, two low temperature mixing water pumps 17 with a total flow rate Q 5 Working, through flow meter and flow meter The flow value controls the flow of the low-temperature heat medium water pump 16 and the two low-temperature mixed temperature water pumps 17 through the flow meter Control valve The opening degree is changed hourly to achieve the low-temperature mixed water flow rate. When the spherical tank wall temperature rate v t1 Reach v 2 When the two low-temperature mixed temperature water pumps 17 are turned off, the shut-off valve and regulating valve on the low-temperature mixed temperature water bypass 10 are turned off. At this time, the temperature rise rate and thermal stress of the spherical tank wall reach the allowable range of the spherical tank. Only the low-temperature heat medium water pump is operated to supply water to the spherical tank to meet the use requirements. When supplying high-temperature water to other spherical tanks, the water outlet pipes and high-temperature water inlet pipes of different spherical tanks are switched. The rest of the working mode is the same as supplying high-temperature water to the Nth spherical tank. The design flow rates of the low-temperature heat medium water pump 16 and the low-temperature mixed temperature water pump 17 are both Q 6 ;

[0164] When releasing heat to store low-temperature water in the No. 1 energy storage tank, open the shut-off valve on the low-temperature water inlet branch of the first energy storage tank and the shut-off valve on the outlet pipe of the second energy storage tank, and close the shut-off valves on the high-temperature water inlet branch and low-temperature water inlet branch of all other energy storage tanks and the shut-off valves on the drain pipe; close all the shut-off valves of the low-temperature control subsystem, open all the shut-off valves and regulating valves of the high-temperature control subsystem, as well as the high-temperature heat medium water pump 18 and the high-temperature mixed temperature water pump 19, and the high-temperature water flows from the second energy storage tank through the high-temperature control device, all the way to the high-temperature mixed temperature water bypass, and all the way into the heat exchanger for heat exchange. The high-temperature heat medium water pump is operated at a flow rate Q 2 Working, two high temperature mixed temperature water pumps with a total flow rate Q 7 Working, through flow meter and flow meter The flow value controls the flow of the high-temperature heat medium water pump 18 and the two high-temperature mixed temperature water pumps 19 through the flow meter Control valve The opening degree is changed hourly to achieve the high-temperature mixed water flow rate. When the spherical tank wall temperature rate vt3 Reach v 4 When the two high-temperature mixed temperature water pumps are turned off, the shut-off valve and regulating valve on the high-temperature mixed temperature water bypass 9 are turned off. At this time, the cooling rate of the spherical tank wall temperature and the thermal stress reach the allowable range of the energy storage tank. Only the high-temperature heat medium water pump is operated to supply water to the energy storage tank to meet the use requirements. When supplying low-temperature water to other energy storage tanks, the outlet pipes and low-temperature water inlet pipes of different energy storage tanks are switched. The rest of the working mode is the same as supplying high-temperature water to the No. 1 energy storage tank. The design flow rates of the high-temperature heat medium water pump and the high-temperature mixed temperature water pump are both Q 8 .

[0165]

[0166] m t0 =2πh t1 RΔm / 10 6

[0167] Q t1 =m t1 ×c 1

[0168] Q t2 =V t1 ×c 2 ×ρ t0

[0169]

[0170] V t0 : The remaining low-temperature water volume in the spherical tank at the previous moment, m 3 ;

[0171] V t1 : The remaining low-temperature water volume in the spherical tank at a certain time, m 3 ;

[0172] Q t1 : The heat required for unit temperature rise of the spherical tank at a certain moment, MJ / ℃;

[0173] Q t2 : The heat required for the unit temperature rise of the remaining heat medium water in the spherical tank at a certain moment, MJ / ℃;

[0174] v t1 : The rate of change of the spherical tank wall temperature at a certain moment, ℃ / min;

[0175] v 2 : The allowable rate of change of wall temperature when the spherical tank is heated, ℃ / min, with a value of 9-11;

[0176] c 1 : Specific heat capacity of spherical tank metal material, kJ / (kg·℃);

[0177] c 2: Specific heat capacity of low-temperature water in a spherical tank, kJ / (kg·℃);

[0178] c 3 : Specific heat capacity of high-temperature water in a spherical tank, kJ / (kg·℃);

[0179] R: radius of spherical tank, m;

[0180] R t0 : radius of the liquid surface of the spherical tank at a certain moment, m;

[0181] Δm: spherical tank wall thickness, mm;

[0182] m t1 : The mass of the part of the spherical tank in contact with the heat medium water at a certain moment, t;

[0183] ρ t0 : Density of heat medium water in the spherical tank at a certain moment, kg / m 3 ;

[0184] h t0 : The height of the liquid level in the spherical tank at the previous moment;

[0185] h t1 : Liquid level in the spherical tank at a certain moment;

[0186] Q 2 : High-temperature water flow rate when the compressed air energy storage system releases energy under design conditions, t / h;

[0187] Δt: spherical tank wall temperature rate calculation compensation, s, value is 10;

[0188] Q 3 : Low-temperature water flow rate of compressed air energy storage system during energy storage under design conditions, t / h;

[0189] Q 5 : Low-temperature mixed water flow rate at a certain moment, t / h;

[0190] Q 5max : Maximum flow rate of low-temperature mixed water, t / h;

[0191] T 1 : low temperature water temperature, K;

[0192] T 2 : high temperature water temperature, K;

[0193] T t1 : The temperature of low-temperature water in the spherical tank at a certain moment, K;

[0194] ΔT 4 : The design temperature safety margin of the spherical tank wall temperature control is ℃, and the value is 40-50.

[0195] The wall temperature control system realizes the wall temperature control of the energy storage tank in two steps. At the beginning, each energy storage tank controls the temperature of the heat medium water entering the energy storage tank through the mixed temperature water bypass, and controls the temperature difference between the heat medium water and the energy storage tank between 40-50℃. When the liquid level in the energy storage tank rises and the temperature difference between the energy storage tank and the heat medium water decreases, when the calculated wall temperature change rate of the energy storage tank is 9℃ / min-11℃ / min, the low-temperature mixed temperature water / high-temperature mixed temperature water bypass is closed, so that the thermal stress change of the energy storage tank is controlled within the allowable range during the entire heat storage and release process.

[0196] The low-temperature mixed temperature water pump 16 and the low-temperature heat medium water pump 17 have the same design flow rate, and are designed according to the larger value of the low-temperature heat medium water flow rate and the required mixed temperature water volume during heat storage. The low-temperature mixed temperature water pump 16 and the low-temperature heat medium water pump 17 are backup for each other, and no additional backup pump is designed. Both use frequency conversion control.

[0197] The high-temperature mixed temperature water pump 18 and the high-temperature heat medium water pump 19 have the same design flow rate, and are designed according to the larger value of the high-temperature heat medium water flow rate and the required mixed temperature water volume during heat storage. The high-temperature mixed temperature water pump 18 and the high-temperature heat medium water pump 19 are backup for each other, and no additional backup pump is designed. Both use frequency conversion control.

[0198] Under the premise of ensuring the safety of the energy storage tank, the minimum liquid level of the energy storage tank can be controlled below 1.0% during heat storage, and the final temperature of heat storage can be controlled within a reduction of 10°C, which can ensure the efficiency of the energy storage power station.

[0199] Under the premise of ensuring the safety of the energy storage tank, the minimum liquid level of the energy storage tank can be controlled below 1.5% during heat release, and the final temperature of the low-temperature water in the energy storage tank can be controlled within an increase of 12°C, which can reduce the consumption of cooling water.

[0200] The design liquid level of the energy storage spherical tank is different from the operating liquid levels of heat storage and heat release, which can reduce the temperature drop of heat storage during heat storage and the temperature rise of low-temperature water during heat release.

Claims

1. A compressed air energy storage spherical tank inversion operation system, characterized by: An energy storage system comprises a plurality of energy storage spherical tanks (1) connected in parallel, a constant pressure system connected to the energy storage spherical tanks (1), and two wall temperature control devices connected to the energy storage system in parallel, wherein the wall temperature control device comprises a low temperature control device (3) and a high temperature control device (4), and along the flow direction of high temperature water and low temperature water, a low temperature water inlet main pipeline and a high temperature water inlet main pipeline are respectively connected to the plurality of energy storage spherical tanks (1) of the energy storage system, a water outlet pipe (8) of the energy storage spherical tank (1) is respectively connected to the low temperature control device (3) and the high temperature control device (4) through pipelines, the low temperature control device is connected to the high temperature water inlet pipe through a low temperature mixed water bypass (10), the high temperature control device (4) is connected to the low temperature water inlet pipe through a high temperature mixed water bypass (9), and the low temperature control device (3) and the high temperature control device (4) are respectively connected to a heat exchanger at the same time.

2. A compressed air energy storage spherical tank inversion operation system according to claim 1, characterized in that: The constant pressure system comprises a constant pressure water tank (2), the constant pressure water tank (2) and the constant pressure pipe of the energy storage spherical tank (1) are simultaneously connected through a pipeline 1 and a pipeline 2 provided with a constant pressure water pump, a flow meter (13), a regulating valve (15) and a shut-off valve (14) are arranged in series on the pipeline 1, two branches are arranged in parallel on the pipeline 2 and a constant pressure water pump (5) is arranged on each branch, and a shut-off valve (14) is arranged on the left and right sides of each branch of the constant pressure water pump (5), respectively, manual shut-off valves (7) are arranged on both sides of the parallel branches of the pipeline 2 to connect with the constant pressure water tank (2), and a flow meter (13) and a shut-off valve ② are arranged to connect with the constant pressure pipe (11), the pipeline 1 and the constant pressure pipe (11) are directly connected, and the pipeline 1 is connected to the pipeline between the flow meter ⑥ and the shut-off valve ② of the pipeline 2 through a pipeline.

3. A compressed air energy storage spherical tank inverting operation system according to claim 2, characterized in that: Each branch of the pipeline 2 is provided with a filter screen (12) and a check valve (6) on the left and right of the constant pressure water pump (5), and a shut-off valve ① is provided on the constant pressure pipe (11).

4. A compressed air energy storage spherical tank inverting operation system according to claim 1, characterized in that: The low-temperature control device (3) comprises three low-temperature control branches connected in parallel, wherein one of the low-temperature control branches is provided with a shut-off valve (14), a regulating valve (15), a filter (12), a low-temperature heat medium water pump (16), a check valve (6), and a shut-off valve (14) in sequence, and the other two low-temperature control branches are provided with a shut-off valve (14), a regulating valve (15), a filter (12), a low-temperature mixed temperature water pump (17), a check valve (6), and a shut-off valve (14) in sequence; the high-temperature control device (4) comprises three high-temperature control branches connected in parallel, wherein one of the high-temperature control branches is provided with a shut-off valve (14), a regulating valve (15), a filter (12), a high-temperature heat medium water pump (18), a check valve (6), and a shut-off valve (14) in sequence, and the other two high-temperature control branches are provided with a shut-off valve (14), a regulating valve (15), a filter (12), a high-temperature mixed temperature water pump (19), a check valve (6), and a shut-off valve (14) in sequence.

5. A compressed air energy storage spherical tank inverting operation system according to claim 4, characterized in that: The pipelines connecting the low-temperature control device (3) and the high-temperature control device (4) to the energy storage system are both provided with shut-off valves (14), and the pipeline connecting the low-temperature control device (3) to the low-temperature mixed water bypass (10) is provided with a flow meter. and a shut-off valve, a flow meter is provided on the pipeline connecting the high temperature control device (4) and the high temperature mixed water bypass (9) and shut-off valves.

6. A compressed air energy storage spherical tank inverting operation system according to claim 5, characterized in that: Along the water flow direction, the high temperature mixed water bypass (9) is provided with relevant shut-off valves, flow meters, and regulating valve The low-temperature mixed water bypass (10) is provided with a shut-off valve, a flow meter and the like. and regulating valve The connecting pipes between the energy storage system and the low-temperature control device (3), the low-temperature control device (3) and the low-temperature mixed water bypass (10), and the connecting pipes between the low-temperature control device (3) and the low-temperature mixed water bypass (10) constitute a low-temperature control subsystem, and the connecting pipes between the energy storage system and the high-temperature control device (4), the high-temperature control device (4) and the high-temperature mixed water bypass (9), and the connecting pipes between the high-temperature control device (4) and the high-temperature mixed water bypass (9) constitute a high-temperature control subsystem.

7. A compressed air energy storage spherical tank inversion operation system according to claim 2, characterized in that: The energy storage spherical tanks of the heat storage system include energy storage spherical tanks No. 1 to No. N. Each energy storage spherical tank is provided with a water outlet pipe connected to a wall temperature control device. All water outlet pipes (8) are provided with shut-off valves. Each energy storage spherical tank is provided with a low-temperature water inlet branch pipe and a high-temperature water inlet branch pipe connected to the low-temperature water inlet main pipe and the high-temperature water inlet main pipe respectively. The low-temperature water inlet branch pipe and the high-temperature water inlet branch pipe are provided with shut-off valves respectively. During an energy storage cycle, the state of energy storage spherical tank No. 1 is always kept to store low-temperature water or be empty, and the state of energy storage spherical tank No. N is kept to store high-temperature water or be empty. The constant pressure system of the entire spherical tank heat storage system is provided at energy storage spherical tank No.

1. A constant pressure pipe (8) is provided at the bottom of energy storage spherical tank No.

1. The constant pressure water tank (2) is a normal pressure water tank. The constant pressure water pump is operated at power frequency, one in operation and one in standby, and the manual shut-off valve is a normally open valve.

8. A method for stabilizing the pressure of a compressed air energy storage spherical tank inverting operation system, characterized in that The following steps are involved: During heat storage, when the pressure of the energy storage spherical tank is higher than P7, the constant pressure water discharge system is opened, and the regulating valve (15) on the pipeline 1 is adjusted to supply water from the No. 1 spherical tank to the constant pressure water tank at a flow rate of Q4. At this time, the shut-off valve ② is closed, the two constant pressure water pumps (5) are closed, the shut-off valve ①, the shut-off valve and the regulating valve on the pipeline 1 are opened, and the pressure difference between the energy storage spherical tank (1) and the constant pressure water tank (2) is used to discharge water to the constant pressure water tank (2). By comparing the value of the flow meter (13) on the pipeline 1 with the constant value Q 4 is used to adjust the opening of the regulating valve (15) on the pipeline 1 to keep the water discharge flow unchanged and maintain the pressure of the spherical tank within the normal operating range. When the pressure of the spherical tank reaches P8, the shut-off valve ① and the shut-off valve (14) are closed to close the constant pressure water discharge system. In the event of an accident, when the pressure of the storage tank still rises or is in the P7 state after the spherical tank discharges water at a flow rate of Q4, the regulating valve on the pipeline 1 is fully opened to discharge water to the constant pressure water tank at a flow rate of Q5. When the pressure drops to P8, the constant pressure water discharge system is closed. During heat release, when the pressure of the energy storage tank is lower than P5, the constant pressure system is turned on. At this time, the shut-off valve ① and the shut-off valve ② are opened, one constant pressure water pump (5) is turned on, the other constant pressure water pump (5) is turned off, the shut-off valve (14) and the regulating valve (15) on the pipeline 1 are closed, and the flow rate of the opened constant pressure water pump is controlled by comparing the flow meter value on the pipeline 2 with the constant value Q1. The head of the constant pressure water pump is P6. The energy storage tank No. 1 is supplemented with high-pressure and low-temperature water through this constant pressure water pump to maintain the pressure of the energy storage tank (1) within the normal range. When the pressure of the energy storage tank reaches P6, the constant pressure water pump is turned off first, and then the shut-off valve ① and the shut-off valve ② are closed to turn off the constant pressure system. In the accident condition, when the energy storage tank is supplied with water at the flow rate Q1, the pressure of the energy storage tank is still reduced or in the P5 state. At this time, another constant pressure water pump is turned on to supply water to the energy storage tank No. 1 at twice the flow rate Q1. When the pressure rises to P6, the constant pressure system is turned off.

9. The pressure stabilization method of the compressed air energy storage spherical tank inverting operation system according to claim 8 is characterized by: Q5=n7Q4 P2=saturation pressure(T2) P0=min(saturation pressure(T2+ΔT3),n4×saturation pressure(T2)) P1=n5P0 P3=min(saturation pressure(T2+ΔT4),n6×saturation pressure(T2)) P4=P1-ΔP9 P7=P4-ΔP 10 P8=P3+ΔP 10 Q1: constant pressure water pump flow, t / h; Q2: High-temperature water flow rate when the compressed air energy storage system releases energy under design conditions, t / h; Q3: Low-temperature water flow rate when the compressed air energy storage system is storing energy under design conditions, t / h; Q4: Constant pressure water discharge flow, t / h; Q5: Maximum flow rate of the regulating valve, t / h; ρ1: low temperature water density, kg / m 3 ; ρ2: High temperature water density, kg / m 3 ; V1: constant pressure water tank volume, m 3 ; T1: low temperature water temperature, K; T2: high temperature water temperature, K; ΔT3: safety margin of spherical tank design temperature, °C, ranging from 5 to 10. When P2 is large, a small value is taken, and when P2 is small, a large value is taken. ΔT4: safety margin of spherical tank operating temperature, °C, value range is 3-5, take a smaller value when P2 is larger, take a larger value when P2 is smaller; P0: spherical tank design pressure, MPa; P1: Opening pressure of spherical tank safety valve, MPa; P2: high temperature water saturation pressure, MPa; P3: lower limit of constant pressure operation pressure of spherical tank, MPa; P4: upper limit of the constant pressure operation pressure of the spherical tank, MPa; P5: Opening pressure of constant pressure water supply of spherical tank, MPa; P6: spherical tank constant pressure water supply closing pressure, MPa; P7: Opening pressure of spherical tank constant pressure water discharge, MPa; P8: spherical tank constant pressure drain closing pressure, MPa; ΔP9: safety margin of spherical tank operating pressure, MPa, ranging from 0.05 to 0.

1. A larger value is taken when P2 is larger, and a smaller value is taken when P2 is smaller; ΔP 10 : Spherical tank constant pressure safety margin, MPa, value 0.1-0.2, take a smaller value when P2 is larger, take a larger value when P2 is smaller; n1: constant pressure water supply flow temperature reduction coefficient, the value is 0.8-0.9; n2: constant pressure water tank temperature reduction coefficient, value is 0.7-0.8; n3: Safety factor of constant pressure water tank capacity, including the change of low temperature water flow rate of heat storage system when ambient temperature changes, with a value of 1.2-1.3; n4: spherical tank pressure safety factor, ranging from 1.25 to 1.5, taking a smaller value when P2 is larger, and taking a larger value when P2 is smaller; n5: spherical tank safety valve tripping coefficient, ranging from 0.8 to 0.95, taking a larger value when P0 is larger, and taking a smaller value when P2 is smaller; n6: spherical tank operating pressure safety factor, ranging from 1.1 to 1.25, taking a smaller value when P2 is larger, and taking a larger value when P2 is smaller; n7: spherical tank accident water release coefficient, ranging from 1.5 to 2, taking a smaller value when P4 is larger, and taking a larger value when P2 is smaller; t1: compressed energy storage time in a compressed air energy storage system energy storage and release cycle.

10. A method for emptying a compressed air energy storage spherical tank in an emptying operation system, characterized in that The following steps are involved: When the heat storage is storing high-temperature water in the Nth spherical tank, the shut-off valve on the high-temperature water inlet branch of the Nth energy storage spherical tank and the shut-off valve on the outlet pipe of the N-1th energy storage spherical tank are opened, and the shut-off valves on the high-temperature water inlet branch and low-temperature water inlet branch of all other energy storage spherical tanks and the shut-off valves on the drain pipe are closed; All shut-off valves of the high-temperature control subsystem are closed, and all shut-off valves and regulating valves of the low-temperature control subsystem as well as the low-temperature heat medium water pump (16) and the low-temperature mixed temperature water pump (17) are opened. The low-temperature water passes through the low-temperature control device, goes to the low-temperature mixed temperature water bypass, and enters the heat exchanger for heat exchange. The low-temperature heat medium water pump (16) works at a flow rate of Q3, and the two low-temperature mixed temperature water pumps (17) work at a total flow rate of Q5. The flow meter and flow meter The flow value controls the flow of the low-temperature heat medium water pump (16) and the two low-temperature mixing water pumps (17) through the flow meter Control valve The opening degree changes hourly to achieve the low-temperature mixed water flow rate; When the wall temperature rate v of the energy storage tank t1 When v2 is reached, the two low-temperature mixed temperature water pumps (17) are turned off, and the shut-off valve and regulating valve on the low-temperature mixed temperature water bypass (10) are turned off. At this time, the temperature rise rate and thermal stress of the spherical tank wall temperature reach the allowable range of the energy storage spherical tank. Only the low-temperature heat medium water pump (16) is operated to supply water to the energy storage spherical tank to meet the use requirements. When supplying high-temperature water to other energy storage spherical tanks, the water outlet pipes and high-temperature water inlet pipes of different energy storage spherical tanks are switched. The rest of the working mode is the same as supplying high-temperature water to the Nth spherical tank. The design flow rates of the low-temperature heat medium water pump (16) and the low-temperature mixed temperature water pump (17) are both Q6. When releasing heat to store low-temperature water in the No. 1 energy storage tank, open the shut-off valve on the low-temperature water inlet branch of the first energy storage tank and the shut-off valve on the outlet pipe of the second energy storage tank, and close the shut-off valves on the high-temperature water inlet branch and low-temperature water inlet branch of all other energy storage tanks and the shut-off valves on the drain pipe; All shut-off valves of the low-temperature control subsystem are closed, and all shut-off valves and regulating valves of the high-temperature control subsystem as well as the high-temperature heat medium water pump (18) and the high-temperature mixed temperature water pump (19) are opened. The high-temperature water flows from the second energy storage spherical tank through the high-temperature control device, goes to the high-temperature mixed temperature water bypass, and enters the heat exchanger for heat exchange. The high-temperature heat medium water pump works at a flow rate of Q2, and the two high-temperature mixed temperature water pumps work at a total flow rate of Q7. The high-temperature mixed temperature water pump (19) is connected to the heat exchanger through the flow meter. and flow meter The flow value controls the flow of the high-temperature heat medium water pump (18) and the two high-temperature mixed temperature water pumps (19) through the flow meter Control valve The opening degree changes hour by hour to achieve high-temperature mixed water flow; When the wall temperature rate v of the energy storage tank t3 When v4 is reached, the two high-temperature mixed temperature water pumps are turned off, and the shut-off valve and regulating valve on the high-temperature mixed temperature water bypass (9) are turned off. At this time, the cooling rate of the wall temperature of the energy storage tank and the thermal stress reach the allowable range of the energy storage tank. Only the high-temperature heat medium water pump is operated to supply water to the energy storage tank to meet the use requirements. When supplying low-temperature water to other energy storage tanks, the outlet pipes and low-temperature inlet pipes of different energy storage tanks are switched. The rest of the working mode is the same as supplying high-temperature water to the No. 1 energy storage tank. The design flow rates of the high-temperature heat medium water pump and the high-temperature mixed temperature water pump are both Q8.

11. A method for reversing a compressed air energy storage spherical tank according to claim 10, characterized in that: m t0 =2πh t1 RΔm / 10 6 Q t1 =m t1 ×c1 Q t2 =V t1 ×c2×ρ t0 V t0 : The remaining low-temperature water volume in the spherical tank at the previous moment, m 3 ; V t1 : The remaining low-temperature water volume in the spherical tank at a certain time, m 3 ; Q t1 : The heat required for unit temperature rise of the spherical tank at a certain moment, MJ / ℃; Q t2 : The heat required for unit temperature rise of the remaining heat medium water in the spherical tank at a certain moment, MJ / ℃; v t1 : The rate of change of the spherical tank wall temperature at a certain moment, ℃ / min; v2: allowable rate of change of wall temperature when the spherical tank is heated, ℃ / min, with a value of 9-11; c1: Specific heat capacity of spherical tank metal material, kJ / (kg·℃); c2: Specific heat capacity of low-temperature water in a spherical tank, kJ / (kg·℃); c3: Specific heat capacity of high-temperature water in a spherical tank, kJ / (kg·℃); R: radius of spherical tank, m; R t0 : radius of the liquid surface of the spherical tank at a certain moment, m; Δm: spherical tank wall thickness, mm; m t1 : The mass of the part of the spherical tank in contact with the heat medium water at a certain moment, t; ρ t0 : Density of heat medium water in the spherical tank at a certain moment, kg / m 3 ; h t0 : The height of the liquid level in the spherical tank at the previous moment; h t1 : Liquid level in the spherical tank at a certain moment; Q2: High-temperature water flow rate when the compressed air energy storage system releases energy under design conditions, t / h; Δt: spherical tank wall temperature rate calculation compensation, s, value 10; Q3: Low-temperature water flow rate when the compressed air energy storage system is storing energy under design conditions, t / h; Q5: Low-temperature mixed water flow rate at a certain moment, t / h; Q 5max : Maximum flow rate of low-temperature mixed water, t / h; T1: low temperature water temperature, K; T2: high temperature water temperature, K; T t1 : The temperature of low-temperature water in the spherical tank at a certain moment, K; ΔT4: Design temperature safety margin for spherical tank wall temperature control, ℃, with a value of 40-50.

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