Ultra-high temperature heat pump coupled lithium battery composite energy storage system and operation method

Abstract

The application discloses a kind of ultra-high temperature heat pump coupling lithium battery composite energy storage systems and operating method for new energy consumption, mainly including ultra-high temperature heat pump system, fused salt energy storage system, steam power generation system, lithium battery energy storage system and energy management system, its characteristics are that ultra-high temperature heat pump system is combined with lithium battery energy storage system energy storage, and is controlled by energy management system, energy management system is controlled and is deployed when new energy power input, deployment strategy is that ultra-high temperature heat pump system is consumed in its rated operation interval and does not exceed its maximum variable load rate power, lithium battery energy storage system is consumed in the power outside the rated operation interval of ultra-high temperature heat pump, and simultaneously consumed the power outside the maximum load rate of ultra-high temperature heat pump system, supplement the power outside the maximum load rate of ultra-high temperature heat pump system.The application solves the problem of narrow operating interval of single ultra-high temperature heat pump in new energy consumption scene.

Description

Technical Field

[0001] This invention relates to the fields of heat pump systems, new energy consumption, energy storage power generation, and green steam supply, and particularly to an ultra-high temperature heat pump coupled lithium battery composite energy storage system and its operation method for new energy consumption. Background Technology

[0002] The intermittent, fluctuating, and random nature of new energy sources such as wind and solar power leads to significant curtailment issues, necessitating efficient energy storage technologies to achieve full integration of these renewable energy sources. Ultra-high temperature heat pump energy storage, with its advantages of high electro-thermal conversion efficiency, long-term energy storage capability, and adaptability to high-power consumption, is a crucial technology for coupled wind and solar energy storage. However, ultra-high temperature heat pumps have an effective stable operating range, unable to handle excess electricity outside this range, resulting in insufficient renewable energy integration. Furthermore, the load increase / decrease rate of heat pump units is constrained by thermodynamic processes such as the compressor and working fluid cycle, resulting in a limited dynamic response rate. This makes it difficult to match the rapid fluctuations in renewable energy output, ranging from seconds to minutes, leading to power tracking lag and further exacerbating curtailment and unit operating condition oscillations. To address these shortcomings, there is an urgent need in this field for a composite energy storage system that can cover the entire power range, has a fast response speed, and ensures stable operation of the heat pump. Summary of the Invention

[0003] This invention provides an ultra-high temperature heat pump coupled with lithium battery composite energy storage system and operation method for new energy consumption. It can solve the problems of narrow operating range, slow dynamic response and inability to fully consume new energy in new energy consumption scenarios by a single ultra-high temperature heat pump, so as to realize full consumption of new energy, ensure stable operation of heat pump and improve the overall energy utilization efficiency of the system.

[0004] The technical solution of the present invention is as follows: The first aspect of this invention provides an ultra-high temperature heat pump coupled with a lithium battery composite energy storage system for new energy consumption, which mainly includes an ultra-high temperature heat pump system, a molten salt energy storage system, a steam power generation system, a lithium battery energy storage system, and an energy management system, wherein... Ultra-high temperature heat pump systems are used to convert electricity generated by wind and solar power into heat to raise the temperature of molten salt; Molten salt energy storage systems are used to couple ultra-high temperature heat pump systems to store thermal energy; Steam power generation systems use thermal energy stored in molten salt energy storage systems to generate steam and produce electricity; The lithium battery energy storage system is used to absorb electricity that is below or above the rated operating period of the ultra-high temperature heat pump system, and at the same time absorb electricity that exceeds the maximum load increase rate of the ultra-high temperature heat pump system and supplement electricity that exceeds the maximum load decrease rate of the ultra-high temperature heat pump system. The energy management system is used for unified control and allocation when new energy power is input. The allocation strategy is that the ultra-high temperature heat pump system absorbs the electricity within its rated operating range and does not exceed its maximum load change rate, while the lithium battery energy storage system absorbs the electricity below or above the rated operating period of the ultra-high temperature heat pump, and at the same time absorbs the electricity exceeding the maximum load increase rate of the ultra-high temperature heat pump system and supplements the electricity exceeding the maximum load decrease rate of the ultra-high temperature heat pump system.

[0005] As a preferred embodiment of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption described in this invention, the energy management system is used for multi-source data acquisition and status monitoring, as well as power range determination and intelligent allocation. The multi-source data acquisition and status monitoring includes real-time acquisition of wind and solar power station output data, ultra-high temperature heat pump operating status, lithium battery energy storage system parameters, and grid connection point operating parameters. The power range determination and intelligent allocation includes real-time comparison and calculation of new energy output and heat pump rated operating range, new energy fluctuation amplitude and heat pump maximum load change rate, so as to automatically execute power allocation strategies.

[0006] As a preferred embodiment of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption described in this invention, the lithium battery energy storage system includes a PCS energy storage converter, battery clusters, a BMS battery management system, and boost power distribution equipment. The PCS energy storage converter is used to realize bidirectional AC-DC conversion. During charging, it rectifies the new energy AC power into DC power and stores it in the battery cluster. During discharging, it inverts the battery DC power into AC power and sends it to the energy management system for processing. The battery cluster is used to store electrical energy in the form of chemical energy; The BMS battery management system is used to collect the voltage, current, temperature, and SOC parameters of the battery cluster in real time, and to perform overcharge, over-discharge, and over-temperature protection and cell equalization control. The step-up power distribution equipment is used to step up the low-voltage electricity output by the entire system to the rated voltage level of the power grid.

[0007] As a preferred embodiment of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption described in this invention, the ultra-high temperature heat pump system includes an ultra-high temperature heat pump frequency conversion control system, a compressor, an expander, a heat absorber, and a heat releaser. The ultra-high temperature heat pump frequency conversion control system is used for information interaction with the energy management system. The compressor consumes electrical energy to heat and pressurize the heat pump working fluid. The expander recovers the pressure energy of the heat pump working fluid to reduce system energy consumption. The heat absorber absorbs external waste heat to heat the heat pump working fluid. The heat releaser cools the heat pump working fluid while simultaneously increasing the temperature of the molten salt in the molten salt energy storage system.

[0008] As a preferred embodiment of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption described in this invention, the energy management system includes an industrial PLC core controller, a multi-functional power measurement and control instrument, a current / voltage transformer, a temperature / pressure / flow transmitter, and is equipped with a communication module, an industrial Ethernet switch, a fiber optic transceiver, and shielded signal cables to form a signal transmission network. The energy management system collects real-time data on wind and solar power plant output, ultra-high temperature heat pump temperature, pressure, and flow operating parameters, lithium battery SOC and power parameters, and grid connection point electrical parameters through the multi-functional power measurement and control instrument, current / voltage transformer, and temperature / pressure / flow transmitter. The industrial PLC core controller has a built-in control algorithm that performs real-time power range determination and new energy output fluctuation rate calculation. Based on a preset power allocation strategy, it generates a target power command, which is sent to the ultra-high temperature heat pump frequency conversion control system of the ultra-high temperature heat pump system and the PCS energy storage converter of the lithium battery energy storage system via the communication link of the signal transmission network. The latter adjusts the heat pump power consumption and the lithium battery charging and discharging power, respectively, to form a closed-loop coordinated control.

[0009] As a preferred embodiment of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption described in this invention, the steam power generation system includes a molten salt steam generator, a steam turbine generator set, a condenser, a feedwater pump, a first flow meter, a second flow meter, a first regulating valve, and a second regulating valve. The molten salt steam generator is used to generate steam by exchanging heat between feedwater and molten salt; the steam turbine generator set is used to convert steam thermal energy into electrical energy; the condenser is used to cool the steam at the turbine outlet into water; the feedwater pump is used to pressurize the feedwater to a specified pressure; the first flow meter is used to measure the total steam flow rate generated by the molten salt steam generator; the second flow meter is used to measure the steam flow rate used for power generation; the first regulating valve controls the makeup water flow rate by adjusting the valve opening; the second regulating valve controls the steam flow rate used for power generation by adjusting the valve opening; and the remaining steam is used as externally supplied steam.

[0010] As a preferred embodiment of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption as described in this invention, the molten salt energy storage system includes a cold salt tank, a hot salt tank, a cold salt circulation pump, and a hot salt circulation pump; wherein, the cold salt tank is used to store cold salt, the hot salt tank is used to store hot salt, the cold salt circulation pump is used to transport the cold salt to the heat exchanger for heating and then into the hot salt tank, and the hot salt circulation pump is used to transport the hot salt to the molten salt steam generator of the steam power generation system for cooling and then into the cold salt tank.

[0011] The second aspect of the present invention provides an operation method for an ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption as described above. Specifically, when wind power or photovoltaic new energy power is input, it is uniformly controlled and allocated by an energy management system. The power allocation strategy of the energy management system is that the ultra-high temperature heat pump system consumes the power within its rated operating range and does not exceed its maximum load change rate, while the lithium battery energy storage system consumes the power below or above the rated operating period of the ultra-high temperature heat pump system, and simultaneously consumes the power exceeding the maximum load increase rate of the ultra-high temperature heat pump system and supplements the power exceeding the maximum load decrease rate of the ultra-high temperature heat pump system.

[0012] As a preferred method for operating the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption as described in this invention, The power allocation strategies of the energy management system can be categorized as follows: (1) Wind and solar power output < 20MW: The ultra-high temperature heat pump system is on standby, and all new energy power is sent to the lithium battery energy storage system for charging; (2) 20MW≤wind and solar power output≤100MW and the fluctuation rate does not exceed the maximum load increase and decrease rate of the heat pump: the ultra-high temperature heat pump undertakes all the new energy output to complete the heat storage, the lithium battery is in thermal standby, and the small fluctuations at the second level are smoothed out. (3) Output increase rate exceeds the maximum load increase rate of the heat pump: The ultra-high temperature heat pump increases the load at the maximum rate, and the incremental power exceeding the limit is diverted to the lithium battery for charging and absorption. (4) Output reduction rate exceeds the maximum load reduction rate of the heat pump: The ultra-high temperature heat pump reduces the load at the maximum rate, and the lithium battery discharges to supplement the power difference at the input end, thus slowing down the load reduction rate; (5) Wind and solar power output > 100MW: The ultra-high temperature heat pump maintains full-load operation of 100MW, and the excess power is diverted to lithium battery charging and storage.

[0013] As a preferred embodiment of the operation method of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption as described in this invention, the method further includes the following: The electricity input to the lithium battery energy storage system is allocated by the energy management system and converted from AC to DC by the PCS energy storage converter. It is then input into the battery cluster for charging, converting electrical energy into chemical energy. When discharge is required, the chemical energy in the battery cluster is converted into electrical energy, and the PCS energy storage converter converts the DC to AC and inputs it to the step-up power distribution equipment or allocates it to the heat pump.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Achieve full utilization of new energy across the entire power range. Relying on ultra-high temperature heat pump systems to handle conventional output within the rated range, and lithium battery energy storage systems to supplement electricity outside the range, and through coordinated regulation by the energy management system, fill the blind spots of single heat pump utilization, and significantly improve the utilization rate of new energy.

[0015] 2. Ensure the stable operation of the ultra-high temperature heat pump unit in the ultra-high temperature heat pump system and reduce equipment losses. By diverting the power under extreme operating conditions through the lithium battery energy storage system, the frequent start-stop and operating condition jumps caused by the heat pump exceeding or falling below its output limit are avoided, so that the heat pump always maintains operation in the optimal stable range, reducing thermal stress loss and extending the service life of the equipment.

[0016] 3. The complementary advantages of ultra-high temperature heat pumps and lithium batteries enhance the overall system efficiency and economy. The ultra-high temperature heat pump system leverages its advantages of efficient electro-thermal conversion and long-term, large-capacity energy storage, while the lithium battery energy storage system handles the rapid storage and release of low-power, excess power. Furthermore, its millisecond-level response can compensate for the insufficient load increase / decrease rate of the heat pump. The two work together to balance energy storage efficiency and operating costs.

[0017] 4. Enhance the grid compatibility of new energy sources such as wind power and photovoltaics, and improve the grid regulation capability. The composite energy storage of this invention combines the high-power stable peak-shaving capability of heat pumps with the rapid power regulation capability of lithium batteries, which can smooth out power fluctuations in all dimensions of wind and solar power, output stable and controllable grid-connected power, and effectively ensure the balance of grid supply and demand.

[0018] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the ultra-high temperature heat pump coupled lithium battery composite energy storage system of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the power allocation strategy of the energy management system in Embodiment 1 of the present invention; Figure 1 The meanings of the numbers in the table are as follows: 1-Ultra-high temperature heat pump system, 2-Cold salt tank, 3-Hot salt tank, 4-Cold salt circulation pump, 5-Hot salt circulation pump, 6-Molten salt steam generator, 7-Steam turbine generator set, 8-Condenser, 9-Feed water pump, 10-Make-up water, 11-First regulating valve, 12-Second regulating valve, 13-First flow meter, 14-Second flow meter, 15-External steam supply, 16-PCS energy storage converter, 17-Battery cluster, 18-BMS battery management system, 19-Step-up power distribution equipment, 20-Energy management system, 21-New energy power input. Detailed Implementation

[0020] This invention provides an ultra-high temperature heat pump coupled with a lithium battery composite energy storage system for new energy consumption, which mainly includes an ultra-high temperature heat pump system, a molten salt energy storage system, a steam power generation system, a lithium battery energy storage system, and an energy management system. The ultra-high temperature heat pump system is used to convert electricity generated by wind and solar power into heat to raise the temperature of molten salt; preferably, the compressor outlet heating temperature of the ultra-high temperature heat pump system is greater than or equal to 500°C.

[0021] Molten salt energy storage systems are used in conjunction with ultra-high temperature heat pump systems to store thermal energy; Steam power generation systems use thermal energy stored in molten salt energy storage systems to generate steam and produce electricity; The lithium battery energy storage system is used to absorb electricity that is below or above the rated operating period of the ultra-high temperature heat pump system, and at the same time absorb electricity that exceeds the maximum load increase rate of the ultra-high temperature heat pump system and supplement electricity that exceeds the maximum load decrease rate of the ultra-high temperature heat pump system. The energy management system is used for unified control and allocation when new energy power is input. The allocation strategy is that the ultra-high temperature heat pump system absorbs the electricity within its rated operating range and does not exceed its maximum load change rate, while the lithium battery energy storage system absorbs the electricity below or above the rated operating period of the ultra-high temperature heat pump, and at the same time absorbs the electricity exceeding the maximum load increase rate of the ultra-high temperature heat pump system and supplements the electricity exceeding the maximum load decrease rate of the ultra-high temperature heat pump system.

[0022] The technical solution of this invention is characterized by the combined energy storage of an ultra-high temperature heat pump system and a lithium battery energy storage system, with the energy management system handling the allocation and control. A further characteristic of this invention is that the ultra-high temperature heat pump prioritizes the consumption of new energy power within its rated operating range that does not exceed the maximum load change rate, while the lithium battery energy storage provides a targeted solution for consuming surplus electricity and power gaps outside the rated operating range of the heat pump that exceed the load increase / decrease rate constraints.

[0023] In this document, the range expressed as "from one value to another" is a concise way of representing a range to avoid listing all the values ​​in that range in the specification. Therefore, the description of a particular range of values ​​covers any value within that range as well as the smaller range of values ​​defined by that value, just as if the arbitrary value and the smaller range of values ​​were explicitly stated in the specification.

[0024] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Improvements and adjustments made by those skilled in the art based on the present invention in practical applications still fall within the scope of protection of the present invention.

[0025] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as the combinations of these technical features do not contradict each other, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification. Example 1 Please see Figure 1 This embodiment provides an ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption, mainly comprising an ultra-high temperature heat pump system 1, a molten salt energy storage system, a steam power generation system, a lithium battery energy storage system, and an energy management system; wherein, The ultra-high temperature heat pump system 1 uses a pure gaseous working fluid and operates without phase change. It mainly includes an ultra-high temperature heat pump frequency conversion control system, a compressor, an expander, a heat absorber, a heat releaser, and auxiliary equipment. The ultra-high temperature heat pump frequency conversion control system interacts with the energy management system. The compressor consumes electrical energy to heat and pressurize the heat pump working fluid. The expander recovers the pressure energy of the heat pump working fluid, reducing system energy consumption. The heat absorber absorbs waste heat from the outside environment to heat the heat pump working fluid. The heat releaser cools the heat pump working fluid while simultaneously increasing the temperature of the molten salt. Auxiliary equipment may include valves, pipes, instruments, etc.

[0026] The molten salt energy storage system includes a cold salt tank 2, a hot salt tank 3, a cold salt circulation pump 4, a hot salt circulation pump 5, and other supporting equipment. The cold salt tank 2 stores cold salt, the hot salt tank 3 stores hot salt, the cold salt circulation pump 4 transports the cold salt to the heat exchanger for heating before it enters the hot salt tank 3, and the hot salt circulation pump 5 transports the hot salt to the molten salt steam generator 6 for cooling before it enters the cold salt tank 2. Other supporting equipment may include valves, pipes, instruments, etc.

[0027] The steam power generation system includes a molten salt steam generator 6, a steam turbine generator set 7, a condenser 8, a feedwater pump 9, a first flow meter 13, a second flow meter 14, a first regulating valve 11, a second regulating valve 12, and other supporting equipment. The molten salt steam generator 6 generates steam by exchanging heat between feedwater and molten salt; the steam turbine generator set 7 converts the steam's thermal energy into electrical energy; the condenser 8 cools the steam at the turbine outlet into water; the feedwater pump 9 pressurizes the feedwater to a specified pressure; the first flow meter 13 measures the total steam flow rate generated by the molten salt steam generator 6; the second flow meter 14 measures the steam flow rate used for power generation; the first regulating valve 11 controls the flow rate of the makeup water 10 by adjusting its opening; the second regulating valve 12 controls the steam flow rate used for power generation by adjusting its opening; and the remaining steam is used as external steam supply 15. Other supporting equipment may include valves, pipes, instruments, etc.

[0028] The lithium battery energy storage system includes a PCS energy storage converter 16, battery clusters 17, a BMS battery management system 18, a boost distribution device 19, and other supporting equipment. The PCS energy storage converter 16 performs bidirectional AC-DC conversion, rectifying the new energy AC power into DC power during charging and storing it in the battery clusters 17. During discharging, it inverts the battery DC power back into AC power for processing by the energy management system 20. The battery clusters 17 store electrical energy in the form of chemical energy. The BMS battery management system 18 collects parameters such as voltage, current, temperature, and SOC of the battery clusters in real time, and performs overcharge, over-discharge, and over-temperature protection as well as cell balancing control. The boost distribution device 19 boosts the low-voltage output of the entire system to the grid's rated voltage level. Other supporting equipment includes switches and protection devices to achieve grid connection switching, short-circuit protection, and overload protection.

[0029] The Energy Management System 20 features multi-source data acquisition and status monitoring (real-time acquisition of power output data from wind and solar power plants, operating status of ultra-high temperature heat pumps, parameters of lithium battery energy storage systems, and operating parameters of grid connection points), power range determination and intelligent allocation (real-time comparison and calculation of renewable energy output with the rated operating range of heat pumps, renewable energy fluctuation amplitude with the maximum load change rate of heat pumps, and automatic execution of power allocation strategies). The hardware of the Energy Management System mainly includes an industrial PLC core controller, multi-functional power measurement and control instruments, current / voltage transformers, temperature / pressure / flow transmitters, and a supporting communication module, industrial Ethernet switch, fiber optic transceiver, and shielded signal cables forming a signal transmission network. The energy management system collects real-time data on wind and solar power plant output, ultra-high temperature heat pump temperature, pressure, and flow operating parameters, lithium battery SOC and power parameters, and grid connection point electrical parameters through the aforementioned measurement and control instruments and various sensors. The industrial PLC core controller has a built-in control algorithm that performs real-time power range determination and new energy output fluctuation rate calculation. It generates target power commands according to the preset power allocation strategy and sends them to the ultra-high temperature heat pump frequency conversion control system and PCS energy storage converter 16 via the communication link to adjust the heat pump power consumption and lithium battery charging and discharging power, forming a closed-loop coordinated control.

[0030] This embodiment also provides an operation method for an ultra-high temperature heat pump coupled with a lithium battery composite energy storage system for new energy consumption. The process is as follows: when new energy power is input 21, it is uniformly controlled and allocated by the energy management system 20. The power allocation strategy is that the ultra-high temperature heat pump system consumes power within its rated operating range and not exceeding its maximum load change rate; the lithium battery energy storage system consumes power below or exceeding the rated operating period of the ultra-high temperature heat pump, and simultaneously consumes power exceeding the maximum load increase rate of the ultra-high temperature heat pump system and supplements power exceeding the maximum load decrease rate of the ultra-high temperature heat pump system. This point is... Figure 2 It is clearly shown in the text. Figure 2As shown in Figure (a), within the operating range represented by the vertical axis of the entire new energy output simulation curve, the utilization range of the ultra-high temperature heat pump system is located in the middle, preferably 20%-100% of the heat pump's rated load. The utilization range of the lithium battery energy storage system is located in the high or low range, preferably greater than 100% of the heat pump's rated load or less than 20% of the heat pump's rated load. Figure 2 Figure (b) also shows similar simulation results, with the lithium battery consumption zone located above the high peak of the maximum variable load rate curve of the ultra-high temperature heat pump, while the lithium battery replenishment zone is located below the low peak of the maximum variable load rate curve of the ultra-high temperature heat pump.

[0031] In one specific implementation, the operation process of the ultra-high temperature heat pump coupled lithium battery composite energy storage system for new energy consumption provided in this embodiment is as follows: when new energy power is input 21, it is uniformly controlled and allocated by the energy management system 20. The power allocation strategy is that the ultra-high temperature heat pump system consumes the power within its rated operating range and does not exceed its maximum load change rate, while the lithium battery energy storage system consumes the power below or above the rated operating period of the ultra-high temperature heat pump, and simultaneously consumes the power exceeding the maximum load increase rate of the ultra-high temperature heat pump system and supplements the power exceeding the maximum load decrease rate of the ultra-high temperature heat pump system.

[0032] The operation process of this ultra-high temperature heat pump coupled with lithium battery composite energy storage system is as follows: The energy management system 20 allocates the electricity input to the ultra-high temperature heat pump system to drive the compressor to rotate and compress the working gas, so that the working gas enters a high temperature and high pressure state. The working gas exchanges heat with molten salt in the heat exchanger to cool down. At the same time, the cold salt delivered by the cold salt circulation pump 4 in the cold salt tank 2 is heated and sent to the hot salt tank 3. The working gas then enters the expander to cool down and depressurize, and then enters the absorber to absorb heat from the waste heat source. Finally, it enters the compressor inlet to complete the cycle. The hot salt delivered by the hot salt circulation pump 5 in the hot salt tank 3 and the feed water pumped by the feed water pump 9 exchange heat in the molten salt steam generator 6 to produce steam with certain parameters and then return to the cold salt tank 2. The flow rate of the makeup water 10 is controlled by the first regulating valve 11 and mixes with the water after the condenser 8. It enters the feed water pump 9 to be pressurized and becomes steam in the molten salt steam generator 6. The steam flow rate used for power generation is controlled by the second regulating valve 12. The steam flow rate of the main line and each branch line is measured by the first flow meter 13 and the second flow meter 14 to realize the on-demand distribution of steam. Steam used for power generation enters turbine generator set 7 to generate electricity, which is then boosted and connected to the grid via step-up distribution equipment 19. Steam exiting turbine generator set 7 is condensed in condenser 8 and mixed with makeup water for continued circulation.

[0033] The energy management system 20 allocates power to the lithium battery energy storage system, which is then converted from AC to DC by the PCS energy storage converter 16. This DC power is then fed into the battery clusters 17 for charging, converting electrical energy into chemical energy. When discharging is required, the chemical energy in the battery clusters 17 is converted back into electrical energy, which is then converted back into AC by the PCS energy storage converter 16 and fed into the step-up power distribution equipment 19 or distributed to the heat pump.

[0034] In a specific instance The ultra-high temperature heat pump system has a rated capacity of 100MW. Its stable and efficient operating load range is 20%-100% of the rated capacity, that is, the effective operating power range is 20MW-100MW.

[0035] The thermal storage capacity of the molten salt storage tank meets the full-load thermal storage requirements for 8 hours, and is used to convert new energy power into high-temperature thermal energy for long-term storage.

[0036] The steam turbine generator set has a capacity of 60MW and is connected to the molten salt storage tank. It is used to convert the thermal energy in the storage tank into electrical energy to generate electricity during peak periods when the output of new energy sources is insufficient or when the power grid is in high demand. The full-load operation lasts for about 9-10 hours.

[0037] The total installed capacity of the wind and solar power plant is 120MW, with output covering the entire range of 0-120MW, serving as the new energy power input source for the system.

[0038] The lithium battery energy storage system is configured with a power of 20MW and a capacity of 80MWh, which meets the maximum renewable energy consumption capacity.

[0039] The system operates as follows: New energy power input is uniformly allocated by the energy management system, and the allocation strategy is divided into the following situations: (1) Wind and solar power output < 20MW: The ultra-high temperature heat pump system is on standby, and all new energy power is sent to the lithium battery energy storage system for charging.

[0040] (2) 20MW≤wind and solar power output≤100MW and the fluctuation rate does not exceed the maximum load increase and decrease rate of the heat pump: the ultra-high temperature heat pump undertakes all the new energy output to complete the heat storage, the lithium battery is in thermal standby, and the small fluctuations at the second level are smoothed out.

[0041] (3) Output increase rate exceeds the maximum load increase rate of the heat pump: The ultra-high temperature heat pump increases the load at the maximum rate, and the incremental power exceeding the limit is diverted to the lithium battery for charging and absorption.

[0042] (4) Output reduction rate of the ultra-high temperature heat pump: The ultra-high temperature heat pump reduces the load at the maximum rate, and the lithium battery discharges to make up for the power difference at the input end, thus slowing down the load reduction rate.

[0043] (5) Wind and solar power output > 100MW: The ultra-high temperature heat pump maintains full-load operation of 100MW, and the excess power is diverted to lithium battery charging and storage.

[0044] The electricity generated by wind and solar power is distributed by the energy management system. The energy allocated to the heat pump side is input to the compressor of the ultra-high temperature heat pump system. Operating parameters are collected in real time through compressor inlet pressure sensors, outlet pressure sensors, working fluid temperature sensors, and speed and frequency acquisition modules. Based on real-time power allocation commands, the energy management system adaptively matches the heat pump's operating load through the unit's variable load system, precisely adapting to surplus renewable energy output and strictly controlling the unit's load increase / decrease rate within the equipment's rated limits, ensuring the heat pump operates at high efficiency and stability throughout the entire process. The high-temperature, high-pressure gaseous working fluid, pressurized and heated by the compressor, enters the exothermic device. The system monitors the heat exchange condition in real time through exothermic device inlet and outlet working fluid temperatures, molten salt inlet and outlet temperatures, and heat exchange pressure differential sensors. Simultaneously, the system adjusts the electric regulating valve at the cold salt tank outlet and the opening of the molten salt circulation pump to precisely control the outflow rate and velocity of the low-temperature molten salt from the cold salt tank. This allows the low-temperature molten salt to fully exchange heat with the high-temperature working fluid in the exothermic device through countercurrent flow, achieving heat release on the working fluid side and heat absorption and temperature rise on the molten salt side. After heat exchange, the high-temperature molten salt is sent to a hot salt tank for constant-temperature storage. The hot salt tank is equipped with level, temperature, and pressure sensors to monitor the heat storage status in real time. The tank's insulation and pressure relief valves maintain stable pressure and temperature, achieving long-term heat storage. The low-temperature working fluid, after heat release and cooling, continues to flow through an expander. The system monitors the expansion operation using expander inlet and outlet pressure and speed sensors, recovering the working fluid's pressure potential energy and reducing system cycle energy consumption. The low-temperature, low-pressure working fluid, after expansion and depressurization, enters the absorber to absorb ambient waste heat or system waste heat for temperature compensation, and finally flows smoothly back to the compressor inlet, completing a full closed-loop working fluid cycle. Throughout the process, the heat pump operates within its rated high-efficiency range, without exceeding speed or operating conditions, thanks to adjustments made via valves and pump sets linked to various measuring points.

[0045] The lithium battery energy storage system is specifically designed to handle power regulation outside the control limits of ultra-high temperature heat pump systems. This encompasses three operating conditions: absorbing excess electricity generated when renewable energy output is below or exceeds the heat pump's rated operating range; absorbing excess excess electricity exceeding the heat pump's maximum load increase rate; and compensating for system power shortfalls exceeding the heat pump's maximum load decrease rate. Specifically, excess fluctuating renewable energy is fed into the PCS energy storage converter. The device monitors electrical parameters in real time through built-in voltage, current, and frequency sampling modules. Combined with the lithium battery operating status uploaded by the BMS battery management system, this provides data support for precise charge and discharge control. When renewable energy output deviates from the heat pump's rated operating range, or when the output increase rate exceeds the heat pump's limit, generating excess electricity, the energy management system issues a charging command. The PCS energy storage converter rectifies the AC power into stable DC power. In conjunction with voltage stabilization and current limiting control units, and considering battery cluster SOC, temperature, and maximum charging power parameters, the charging strategy is dynamically optimized to safely and fully absorb all types of excess renewable energy and store it in the lithium battery cluster. When the output of new energy sources drops sharply or the heat pump's load reduction rate is insufficient, resulting in a power shortfall, the system triggers the lithium battery discharge compensation mechanism. The electrical energy stored in the lithium battery is inverted by the PCS energy storage converter, and after voltage stabilization and frequency regulation, it outputs qualified AC power. The grid-connected side monitors the grid operating conditions in real time and dynamically adjusts the output power to accurately make up for the power difference beyond the heat pump's load reduction rate constraint, smoothing system power fluctuations and ensuring stable and continuous output of the composite energy storage system.

[0046] The high-temperature molten salt stored in the hot salt tank can release heat to generate electricity on demand, based on grid dispatch needs and new energy output gaps. The system monitors the heat storage status in real time using temperature, pressure, and level sensors in the hot salt tank, precisely adjusting the operation of the electric regulating valve at the tank outlet and the high-temperature molten salt delivery pump to control a constant flow of high-temperature molten salt into the molten salt steam generator. The steam generator is equipped with feedwater flow sensors, pressure sensors, and steam temperature and pressure measuring points to monitor steam production in real time, adjusting the feedwater electric regulating valve and feedwater pump opening to ensure a stable supply of demineralized water to the steam generator. This water exchanges heat with the high-temperature molten salt, increasing its temperature and vaporizing to generate high-temperature, high-pressure steam. The system precisely regulates steam parameters through steam pressure regulating valves and desuperheating / pressure reducing devices to ensure stable steam temperature and pressure within the rated operating range of the turbine generator set or to directly output stable external steam. The qualified high-temperature, high-pressure steam is fed into the turbine generator set, driving the turbine rotor to perform work and rotating the generator to generate electricity. The generator set is equipped with speed, voltage, current, and power measuring points to collect power generation parameters in real time, precisely controlling the power output through excitation regulating devices and active and reactive power regulating units. After power generation, the low-temperature, low-pressure exhaust steam is discharged into the condenser, where it is cooled and condensed into liquid condensate by a circulating cooling water system. Vacuum, temperature, and liquid level sensors monitor the condensation conditions in real time, adjusting the cooling water pump flow to maintain system vacuum stability. The condensed condensate is mixed with system makeup water, pressurized by the condensate pump, and then fed into a low-pressure heater and a high-pressure heater for progressive heating, finally being sent to the steam generator to complete a closed-loop steam-water cycle. The electrical energy output from the generator set is voltage-matched via a switchgear and step-up transformer, and then stabilized and frequency-regulated by a grid-connected switch and relay protection devices before being connected to the public power grid, achieving large-scale and stable grid-connected utilization of thermal energy.

[0047] To ensure the stable and safe operation of the composite energy storage system, the following operations are also included: When operating an ultra-high temperature heat pump system, it is necessary to strictly control the heat pump load within the 20%-100% rated range to avoid problems such as insufficient working fluid flow and compressor surge caused by operating below the minimum stable operating load; avoid frequent start-ups and shutdowns caused by over- or under-limit output of new energy sources, and reduce thermal stress and working fluid loss during start-ups and shutdowns.

[0048] When operating a molten salt energy storage system, the operating temperature range of the molten salt must be strictly controlled. The lower limit should be higher than the freezing point of the molten salt with sufficient anti-condensation margin, and the upper limit should not exceed the thermal decomposition temperature of the molten salt to prevent molten salt from solidifying and clogging pipelines or failing due to high-temperature decomposition. The liquid levels in the cold salt tank and hot salt tank must be maintained within a reasonable range. During heat storage and release, the molten salt flow rate should be precisely controlled by the cold salt circulation pump and hot salt circulation pump to match the heat release power of the heat pump and the heat absorption power of the steam generator. Heat tracing and anti-condensation measures should be taken during system start-up, shutdown, and low-load operation, especially at pipe bends and valves to avoid local low-temperature solidification. During long-term operation, the changes in the composition of the molten salt should be monitored, and it should be tested and replenished regularly to ensure heat exchange efficiency and heat storage capacity.

[0049] During the operation of the steam power generation system, the steam flow and parameters entering the turbine generator unit must be stably controlled through the second regulating valve to avoid large fluctuations in steam pressure and temperature that could affect the safe operation of the turbine. During start-up and shutdown, the warm-up and speed-up procedures must be strictly followed to control the rate of steam temperature rise and prevent thermal stress damage to the blades and rotor. The condenser vacuum must be maintained within the design range; excessively low vacuum will lead to decreased unit efficiency and excessively high exhaust steam temperature. The makeup water flow is controlled by the first regulating valve, and the quality of the makeup water must meet the requirements to avoid scaling and corrosion that could affect the lifespan of the steam generator and turbine. The first and second flow meters must be calibrated regularly to ensure the accuracy of steam flow distribution and to ensure that the power generation output is controllable and adjustable.

[0050] When a lithium battery energy storage system is running, the state of charge (SOC) of the battery cluster should be controlled within the 10%-90% operating range, reserving a charge / discharge margin to avoid overloading with high-power fast charging or deep discharging that accelerates capacity decay. The charge / discharge rate should not exceed the cell's rated value to prevent excessively rapid cell temperature rise and increased polarization under high current. The BMS (Battery Management System) needs to maintain high-frequency sampling and status uploading, and coordinate with millisecond-level power response requirements. Protection thresholds and energy management system scheduling strategies should be set in tandem to avoid frequent protection triggers that cause power interruptions. The PCS (Power Control System) energy storage converter should have a smooth transition between charge and discharge, and the harmonic distortion rate should be controlled to meet grid connection requirements. Long-term operation requires attention to cell consistency, maintaining individual cell voltage differences with balancing strategies, and ensuring that the cell operating temperature is within a suitable range using a temperature control system.

[0051] During the operation of the energy management system, it is necessary to ensure the synchronization of data sampling across all subsystems, aligning the timestamps for wind and solar power output, heat pump status, lithium battery SOC, and grid parameters to avoid power allocation deviations caused by data asynchrony. The scheduling strategy should follow the principle of "heat pump priority, lithium battery supplementation," and hysteresis intervals should be set for power range determination and rate over-limit determination to prevent frequent switching of critical points from causing operational oscillations. A graded fault linkage mechanism should be established, and when any subsystem fails, power transfer, derated operation, or graded shutdown should be executed according to a preset strategy to prevent the fault from escalating. The communication link should be redundantly designed to ensure reliable communication with the monitoring and control devices of each subsystem, and a safety shutdown strategy should be triggered when communication is interrupted. The scheduling algorithm should be regularly verified to check the deviation from actual operation, and the power allocation strategy should be optimized based on historical data to continuously improve the efficiency of new energy consumption and the stability of system operation.

[0052] Under the guidance of the present invention and the above embodiments, those skilled in the art will readily foresee that all the raw materials or their equivalents, processing methods or their equivalents listed or exemplified in the present invention can achieve the present invention, and that the upper and lower limits and range values ​​of the parameters of each raw material and processing method can also achieve the present invention. Examples are not listed one by one here.

Claims

1. A high-temperature heat pump coupled lithium battery composite energy storage system, characterized in that, It mainly includes ultra-high temperature heat pump systems, molten salt energy storage systems, steam power generation systems, lithium battery energy storage systems, and energy management systems, among which, Ultra-high temperature heat pump systems are used to convert electricity generated by wind and solar power into heat to raise the temperature of molten salt; Molten salt energy storage systems are used to couple ultra-high temperature heat pump systems to store thermal energy; Steam power generation systems use thermal energy stored in molten salt energy storage systems to generate steam and produce electricity; The lithium battery energy storage system is used to absorb electricity that is below or above the rated operating period of the ultra-high temperature heat pump system, and at the same time absorb electricity that exceeds the maximum load increase rate of the ultra-high temperature heat pump system and supplement electricity that exceeds the maximum load decrease rate of the ultra-high temperature heat pump system. The energy management system is used for unified control and allocation when new energy power is input. The allocation strategy is that the ultra-high temperature heat pump system absorbs the electricity within its rated operating range and does not exceed its maximum load change rate, while the lithium battery energy storage system absorbs the electricity below or above the rated operating period of the ultra-high temperature heat pump, and at the same time absorbs the electricity exceeding the maximum load increase rate of the ultra-high temperature heat pump system and supplements the electricity exceeding the maximum load decrease rate of the ultra-high temperature heat pump system.

2. The ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 1, characterized in that, The energy management system is used for multi-source data acquisition and status monitoring, as well as power range determination and intelligent allocation. The multi-source data acquisition and status monitoring includes real-time acquisition of wind and solar power plant output data, ultra-high temperature heat pump operating status, lithium battery energy storage system parameters, and grid connection point operating parameters. The power range determination and intelligent allocation includes real-time comparison and calculation of new energy output and heat pump rated operating range, new energy fluctuation amplitude and heat pump maximum load change rate, so as to automatically execute power allocation strategies.

3. The ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 1, characterized in that, The lithium battery energy storage system includes a PCS energy storage converter, battery clusters, a BMS battery management system, and boost power distribution equipment. The PCS energy storage converter is used to realize bidirectional AC-DC conversion. During charging, it rectifies the new energy AC power into DC power and stores it in the battery cluster. During discharging, it inverts the battery DC power into AC power and sends it to the energy management system for processing. The battery cluster is used to store electrical energy in the form of chemical energy; The BMS battery management system is used to collect the voltage, current, temperature, and SOC parameters of the battery cluster in real time, and to perform overcharge, over-discharge, and over-temperature protection and cell equalization control. The step-up power distribution equipment is used to step up the low-voltage electricity output by the entire system to the rated voltage level of the power grid.

4. The ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 1, characterized in that, The ultra-high temperature heat pump system includes an ultra-high temperature heat pump frequency conversion control system, a compressor, an expander, a heat absorber, and a heat releaser. The ultra-high temperature heat pump frequency conversion control system is used to interact with the energy management system. The compressor consumes electrical energy to heat and pressurize the heat pump working fluid. The expander recovers the pressure energy of the heat pump working fluid to reduce system energy consumption. The heat absorber absorbs external waste heat to heat the heat pump working fluid. The heat releaser cools the heat pump working fluid while simultaneously increasing the temperature of the molten salt in the molten salt energy storage system.

5. The ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 1 or 2, characterized in that, The energy management system includes an industrial PLC core controller, multi-functional power measurement and control instruments, current / voltage transformers, temperature / pressure / flow transmitters, and is equipped with a communication module, industrial Ethernet switch, fiber optic transceiver, and shielded signal cables to form a signal transmission network. The energy management system collects real-time data on wind and solar power plant output, ultra-high temperature heat pump temperature, pressure, and flow operating parameters, lithium battery SOC and power parameters, and grid connection point electrical parameters through the multi-functional power measurement and control instruments, current / voltage transformers, and temperature / pressure / flow transmitters. The industrial PLC core controller has a built-in control algorithm that performs real-time power range determination and new energy output fluctuation rate calculation. Based on a preset power allocation strategy, it generates a target power command, which is sent to the ultra-high temperature heat pump frequency conversion control system of the ultra-high temperature heat pump system and the PCS energy storage converter of the lithium battery energy storage system via the communication link of the signal transmission network. This allows for the adjustment of the heat pump power consumption and lithium battery charging and discharging power, respectively, forming a closed-loop coordinated control.

6. The ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 1, characterized in that, The steam power generation system includes a molten salt steam generator, a steam turbine generator set, a condenser, a feedwater pump, a first flow meter, a second flow meter, a first regulating valve, and a second regulating valve. The molten salt steam generator generates steam by exchanging heat between feedwater and molten salt. The steam turbine generator set converts the steam's thermal energy into electrical energy. The condenser cools the steam at the turbine outlet into water. The feedwater pump pressurizes the feedwater to a specified pressure. The first flow meter measures the total steam flow generated by the molten salt steam generator. The second flow meter measures the steam flow used for power generation. The first regulating valve controls the makeup water flow by adjusting its opening. The second regulating valve controls the steam flow used for power generation by adjusting its opening. The remaining steam is used for external supply.

7. The ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 6, characterized in that, The molten salt energy storage system includes a cold salt tank, a hot salt tank, a cold salt circulation pump, and a hot salt circulation pump; wherein, the cold salt tank is used to store cold salt, the hot salt tank is used to store hot salt, the cold salt circulation pump is used to transport cold salt to the heat exchanger for heating and then into the hot salt tank, and the hot salt circulation pump is used to transport hot salt to the molten salt steam generator of the steam power generation system for cooling and then into the cold salt tank.

8. A method for operating the ultra-high temperature heat pump coupled lithium battery composite energy storage system according to any one of claims 1-7, characterized in that, When wind power or photovoltaic new energy power is input, it is uniformly controlled and allocated by the energy management system. The power allocation strategy of the energy management system is to absorb the power within its rated operating range and not exceed its maximum load change rate of the ultra-high temperature heat pump system, and to absorb the power below or above the rated operating period of the ultra-high temperature heat pump system, and at the same time absorb the power exceeding the maximum load increase rate of the ultra-high temperature heat pump system and supplement the power exceeding the maximum load decrease rate of the ultra-high temperature heat pump system.

9. The operation method of the ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 8, characterized in that, The power allocation strategies of the energy management system can be categorized as follows: (1) Wind and solar power output < 20MW: The ultra-high temperature heat pump system is on standby, and all new energy power is sent to the lithium battery energy storage system for charging; (2) 20MW≤wind and solar power output≤100MW and the fluctuation rate does not exceed the maximum load increase and decrease rate of the heat pump: the ultra-high temperature heat pump undertakes all the new energy output to complete the heat storage, the lithium battery is in thermal standby, and the small fluctuations at the second level are smoothed out. (3) Output increase rate exceeds the maximum load increase rate of the heat pump: The ultra-high temperature heat pump increases the load at the maximum rate, and the incremental power exceeding the limit is diverted to the lithium battery for charging and absorption. (4) Output reduction rate exceeds the maximum load reduction rate of the heat pump: The ultra-high temperature heat pump reduces the load at the maximum rate, and the lithium battery discharges to supplement the power difference at the input end, thus slowing down the load reduction rate; (5) Wind and solar power output > 100MW: The ultra-high temperature heat pump maintains full-load operation of 100MW, and the excess power is diverted to lithium battery charging and storage.

10. The operation method of the ultra-high temperature heat pump coupled lithium battery composite energy storage system as described in claim 9, characterized in that, It also includes the following methods: The electricity input to the lithium battery energy storage system is allocated by the energy management system and converted from AC to DC by the PCS energy storage converter. It is then input into the battery cluster for charging, converting electrical energy into chemical energy. When discharge is required, the chemical energy in the battery cluster is converted into electrical energy, and the PCS energy storage converter converts the DC to AC and inputs it to the step-up power distribution equipment or allocates it to the heat pump.

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