A kind of Carnot cell system and control method based on cross-season energy storage technology

Abstract

The application discloses a kind of based on cross-season energy storage technology's Carnot battery system and control method, including cascade heat pump unit, buried pipe heat storage unit, organic Rankine cycle unit and renewable heat source utilization energy storage unit, when external environment temperature is higher in summer, first heat exchange module can be used to heat exchange with external environment and provide heat source for second heat exchange module, and heat exchange is carried out through second heat exchange module and used to heat generation fluid medium, when external environment temperature is lower in winter, first heat exchange module can be used to heat exchange with buried pipe heat storage unit and provide heat source for second heat exchange module, and heat exchange is carried out through second heat exchange module and used to heat generation fluid medium, avoid the influence of energy storage system by external temperature, guarantee its always efficient operation in different seasons.The method of the application solves the technical problem of low power generation efficiency in winter in the prior art Carnot battery energy storage technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a Carnot battery system based on cross-seasonal energy storage technology and a control method. BACKGROUND

[0002] At present, with the exhaustion of fossil energy and the increasing environmental pollution, the proportion of renewable energy, mainly solar energy and wind energy, in the world's energy structure is steadily rising. At the same time, the intermittency and volatility of renewable energy generation pose a huge challenge to the accommodation capacity of the power grid. Energy storage technology can capture, store and release various forms of energy to users when needed, and plays a crucial role in peak shaving, renewable energy grid connection and other aspects of the power system. Existing energy storage technologies, such as pumped storage, compressed air storage and electrochemical storage, are limited by specific geographical conditions and service life in actual application. Although Carnot battery energy storage technology can well solve the above problems, its electrical conversion efficiency is low. Especially in winter, the heat pump system as the core module of the Carnot battery energy storage system performs poorly in terms of energy efficiency due to environmental temperature, which further reduces the electrical conversion efficiency of the Carnot battery system. The existence of the above problems seriously limits the promotion and application of the Carnot battery system.

[0003] In view of this, it is necessary to propose a Carnot battery system based on cross-seasonal energy storage technology and a control method to solve or at least partially solve the above technical problems. SUMMARY

[0004] The main purpose of the present application is to provide a Carnot battery system based on cross-seasonal energy storage technology and a control method, aiming to solve the technical problem of low winter power generation efficiency in the existing Carnot battery energy storage technology.

[0005] To achieve the above purpose, the present application provides a Carnot battery system based on cross-seasonal energy storage technology, comprising a cascade heat pump unit, a buried pipe heat storage unit, an organic Rankine cycle unit and a renewable heat source utilization energy storage unit, the input end of the organic Rankine cycle unit is arranged in parallel with the renewable heat source utilization energy storage unit, the output end of the organic Rankine cycle unit is arranged in parallel with the buried pipe heat storage unit for heat exchange, the first side of the cascade heat pump unit is connected in parallel to the buried pipe heat storage unit, and the second side of the cascade heat pump unit is connected in parallel to the renewable heat source utilization energy storage unit.

[0006] The cascade heat pump unit comprises a first heat-exchange module and a second heat-exchange module, the first heat-exchange module is used for collecting heat from an external environment or a ground pipe heat storage unit and exchanging heat with the second heat-exchange module, the second heat-exchange module is used for collecting heat from the first heat-exchange module and exchanging heat with a renewable heat source utilization energy storage unit, and the renewable heat source utilization energy storage unit is used for heating and warming up a power generation fluid medium at an input end of an organic Rankine cycle unit.

[0007] Further, the first heat-exchange module comprises a first condenser-evaporator, a first compressor, a first regenerator, a first expansion valve, a first evaporator, a second expansion valve and a second evaporator 7, the first compressor, the first condenser-evaporator, the first regenerator, the first expansion valve and the first evaporator are sequentially arranged and communicated through a first pipeline, the first condenser-evaporator is between the first compressor and the first regenerator, and an inlet end and an outlet end of a low-temperature side of the first condenser-evaporator are respectively communicated with the first pipeline;

[0008] A second pipeline is connected in parallel with the first pipeline, a first end of the second pipeline is communicated with the first pipeline and is between the first regenerator and the first expansion valve, a second end of the second pipeline is communicated with the first pipeline and is between the first evaporator and the first regenerator, the second expansion valve is arranged on the second pipeline, and a second evaporator is downstream of the second expansion valve and an inlet end and an outlet end of a high-temperature side of the second evaporator are respectively communicated with the second pipeline;

[0009] An inlet end and an outlet end of a low-temperature side of the second evaporator are respectively communicated with the ground pipe heat storage unit.

[0010] Further, the second heat-exchange module comprises a second compressor, a heat exchanger, a second regenerator and a third expansion valve which are sequentially arranged and communicated through a third pipeline;

[0011] An inlet end and an outlet end of a high-temperature side of the first condenser-evaporator are respectively communicated with the first pipeline;

[0012] The heat exchanger is between the second compressor and the second regenerator, an inlet end and an outlet end of a low-temperature side of the heat exchanger are respectively communicated with the third pipeline, and an inlet end and an outlet end of a high-temperature side of the heat exchanger are respectively communicated with the renewable heat source utilization energy storage unit.

[0013] Further, the organic Rankine cycle unit comprises a power generation cycle module and a power generation cooling module;

[0014] The power generation cycle module comprises, which are arranged in sequence and communicated through a fourth pipeline, an expander, a first heat exchanger, a first pump body and a second heat exchanger, the inlet end and the outlet end of the high-temperature side of the first heat exchanger are communicated with the fourth pipeline respectively, the inlet end and the outlet end of the low-temperature side of the second heat exchanger are communicated with the fourth pipeline respectively, the power generation cooling module comprises, which are arranged in sequence and communicated through a fifth pipeline, a first valve, a second pump body and a cooling tower, the inlet end and the outlet end of the low-temperature side of the first heat exchanger are communicated with the fifth pipeline respectively, the cooling tower is upstream of the first heat exchanger, and the cooling tower is provided with a second valve in parallel outside.

[0015] Further, the renewable heat source utilization energy storage unit comprises a first working medium heating module and a second working medium heating module, the first working medium heating module comprises, which are arranged in sequence and communicated through a sixth pipeline in sequence, a first storage tank body, a control valve three, a power pump body two, a second storage tank body, a control valve four and a water pump, the inlet end and the outlet end of the high-temperature side of the second heat exchanger are communicated with the sixth pipeline respectively, and the second heat exchanger is between the water pump and the second storage tank body;

[0016] The second working medium heating module is connected in parallel on the second storage tank body, and the second working medium heating module comprises, which are arranged in sequence and communicated through a seventh pipeline, a power pump body three and a solar heat collector, and the water inlet end and the water outlet end of the seventh pipeline are communicated with two ports of the second storage tank body respectively.

[0017] Further, the ground pipe heat storage unit comprises a heat exchange cooling module, a heat exchange heating module and a ground heat storage module, the heat exchange cooling module comprises, which are arranged in sequence and communicated through an eighth pipeline, a valve switch one and a valve switch two, two ends of the ground heat storage module are communicated with the eighth pipeline respectively, and the ground heat storage module is between the valve switch one and the valve switch two, and the ground heat storage module is downstream of the valve switch one;

[0018] The heat exchange heating module comprises, which are arranged in sequence and communicated through a ninth pipeline, a power pump body one, a control valve one and a control valve two, two ends of the ground heat storage module are communicated with the ninth pipeline respectively, and the ground heat storage module is between the control valve two and the control valve one, the inlet end and the outlet end of the low-temperature side of the second evaporator are communicated with the ninth pipeline respectively, the second evaporator is downstream of the power pump body one, and the ground heat storage module is upstream of the control valve two.

[0019] The application also provides a Carnot cell control method based on the cross-season energy storage technology.

[0020] The Carnot cell control method based on the cross-season energy storage technology comprises the following steps:

[0021] The power generation-soil source condensing heat recovery mode, if the temperature difference between the input temperature and the output temperature of the power generation medium fluid is not greater than a first threshold value, the Carnot cell system based on the cross-season energy storage technology is controlled to be in the power generation-soil source condensing heat recovery mode, and the fluid medium in the power generation cooling module exchanges heat through the first heat exchanger, and then the power generation waste heat is stored in the ground pipe heat storage unit;

[0022] The composite heating mode, the composite heating mode is an air-solar heating mode in which an air source heating mode and a solar heating mode are fused, or the composite heating mode is a soil-solar heating mode in which a soil source heating mode and a solar heating mode are fused, or the composite heating mode is a single air source heating mode, or the composite heating mode is a single soil source heating mode;

[0023] When in the air-solar heating mode, the first working fluid heating module of the renewable heat source utilization energy storage unit heats the fluid medium by using solar energy, the first heat extraction heat exchange module is used to collect heat from the external environment and exchange heat with the second heat extraction heat exchange module, and the second heat extraction heat exchange module is used to collect heat from the first heat extraction heat exchange module and exchange heat with the fluid medium heated by the renewable heat source utilization energy storage unit.

[0024] When in the soil-solar heating mode, the first working fluid heating module of the renewable heat source utilization energy storage unit heats the fluid medium by using solar energy, the first heat extraction heat exchange module is used to collect heat from the ground pipe heat storage unit and exchange heat with the second heat extraction heat exchange module, and the second heat extraction heat exchange module is used to collect heat from the first heat extraction heat exchange module and exchange heat with the fluid medium heated by the renewable heat source utilization energy storage unit.

[0025] When in the single air source heating mode, the first heat extraction heat exchange module is used to collect heat from the external environment and exchange heat with the second heat extraction heat exchange module, and the second heat extraction heat exchange module is used to collect heat from the first heat extraction heat exchange module and exchange heat with the fluid medium of the renewable heat source utilization energy storage unit.

[0026] When in the single soil source heating mode, the first heat extraction heat exchange module is used to collect heat from the ground pipe heat storage unit and exchange heat with the second heat extraction heat exchange module, and the second heat extraction heat exchange module is used to collect heat from the first heat extraction heat exchange module and exchange heat with the fluid medium in the renewable heat source utilization energy storage unit.

[0027] Further, when in the air-solar heating mode or the soil-solar heating mode, the temperature is controlled by using the bisection method for coarse adjustment and the PI control for fine adjustment, so that the target fluid entering the second storage tank body is within the ideal temperature range, and the method specifically includes the following steps:

[0028] S10, obtaining a current temperature difference between an output temperature of the target fluid and an ideal temperature based on the debugging water outlet temperature sensor;

[0029] S20, determining whether the current temperature difference is within a preset temperature difference range;

[0030] S31, if the current temperature difference is within the preset temperature difference range, obtaining the ideal condensing pressure based on the debugging pressure sensor 1 as an exhaust port pressure of the second compressor;

[0031] S32, if the current temperature difference is not within the preset temperature difference range, determining the ideal condensing pressure according to a high-temperature medium saturation pressure P cse and a minimum condensing pressure P cmin of the high-temperature medium until the current temperature difference is within the preset temperature difference range, wherein the high-temperature medium saturation pressure is a saturation pressure of a high-temperature working medium, and the high-temperature working medium is a fluid medium flowing through the second compressor;

[0032] S40, performing PI control adjustment on the condensing pressure based on the ideal condensing pressure and the current temperature difference to determine a target condensing pressure until the current temperature difference is within the ideal temperature difference range;

[0033] S50, obtaining an intake port pressure of the first compressor as a low-temperature medium evaporation pressure P e of a low-temperature working medium based on the debugging pressure sensor 4;

[0034] S60, calculating an intermediate temperature using the formula:

[0035] T m ={[T c T e (η L -1)+ΔT m ] / (η H -1)} 0.5 +ΔT m / 2, wherein η H =T c C Pw m w (T wos -T wis ) / (T c W H -T e W H ), and η L =T c1 [C Pw m w (T wos -T wis )-W H ] / (T c1 W L -T e WL

[0036] wherein, T m is the intermediate temperature, T c is the high-temperature medium condensing temperature of the high-temperature working medium, T e is the low-temperature evaporation temperature of the low-temperature working medium, η L is the low-temperature stage heat pump thermodynamic perfection, η H is the high-temperature stage heat pump thermodynamic perfection, ΔT m is the heat transfer temperature difference, C Pw is the constant-pressure specific heat capacity of the fluid medium, m w is the flow rate of the target fluid, T wos is the ideal temperature of the target fluid, T wi is the inlet temperature of the target fluid, W H is the high-temperature stage heat pump compression power consumption, W L is the low-temperature stage heat pump compression power consumption, wherein the high-temperature medium condensing temperature T c corresponds to the target condensing pressure, and the low-temperature medium evaporation temperature T e corresponds to the low-temperature medium evaporation pressure P e ; wherein the low-temperature working medium is the fluid medium flowing through the first compressor;

[0037] S70, adjusting the expansion valve of the second compressor in the high-temperature stage heat pump system according to the intermediate temperature.

[0038] Compared with the prior art, the Carnot cell system based on the cross-season energy storage technology has the following beneficial effects:

[0039] ​The application provides a Carnot cell system based on a cross-season energy storage technology, which comprises a cascade heat pump unit, a ground pipe heat storage unit, an organic Rankine cycle unit and a renewable heat source utilization energy storage unit, the high-temperature side of the renewable heat source utilization energy storage unit is used for heat exchange with the input end of the organic Rankine cycle unit to increase the temperature of the power generation fluid medium, the heat collection side of the ground pipe heat storage unit is used for heat exchange with the output end of the organic Rankine cycle unit to reduce the temperature of the power generation fluid medium, thereby the temperature difference between the input end and the output end of the organic Rankine cycle unit is increased to ensure the power generation efficiency; the cascade heat pump unit comprises a first heat collection and exchange module and a second heat collection and exchange module, the first heat collection and exchange module is used for collecting heat from the external environment or the ground pipe heat storage unit and exchanging heat with the second heat collection and exchange module, the second heat collection and exchange module is used for collecting heat from the first heat collection and exchange module and exchanging heat with the renewable heat source utilization energy storage unit, when the external environment temperature is high in summer, the first heat collection and exchange module can exchange heat with the external environment to provide heat source for the second heat collection and exchange module, and the second heat collection and exchange module can exchange heat to increase the temperature of the power generation fluid medium, when the external environment temperature is low in winter, the first heat collection and exchange module can exchange heat with the ground pipe heat storage unit to provide heat source for the second heat collection and exchange module, and the second heat collection and exchange module can exchange heat to increase the temperature of the power generation fluid medium, thereby the energy storage system is prevented from being affected by the external temperature, and the energy storage system can always operate efficiently in different seasons. In summer and the transition season, the soil temperature is low and the temperature difference between the external environment and the soil is large, during the power generation process of the organic Rankine cycle unit, the temperature of the power generation medium fluid after passing through the expander is high, and the waste heat at the first heat exchanger cannot be fully utilized, at this time, the waste heat of the power generation medium fluid after passing through the expander is stored in the ground pipe heat storage unit through the first heat exchanger, in winter, the external environment temperature is low, during the power generation process of the organic Rankine cycle unit, the temperature of the power generation medium fluid after passing through the expander is low, and the efficiency of the organic Rankine cycle module increases with the decrease of the external temperature, at this time, the power generation cycle module and the power generation cooling module can be disconnected to ensure the power generation efficiency. In addition, the efficiency of the cascade heat pump decreases with the decrease of the external temperature. Therefore, in winter, the soil source heat can be utilized to utilize the waste heat stored in summer and the transition season, at this time, the cascade heat pump unit exchanges heat with the ground pipe heat storage unit. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on the drawings shown.

[0041] Figure 1Structure schematic diagram of a Carnot cell system based on cross-season energy storage technology in an embodiment of the present application;

[0042] Figure 2 Structure schematic diagram of a Carnot cell system based on cross-season energy storage technology in an embodiment of the present application;

[0043] Figure 3 Structure schematic diagram of a Carnot cell system based on cross-season energy storage technology in an embodiment of the present application;

[0044] Figure 4 System principle schematic diagram corresponding to a Carnot cell system control method based on cross-season energy storage technology in an embodiment of the present application.

[0045] Legend:

[0046] 100, cascade heat pump unit; 11, first heat extraction heat exchange module; 12, second heat extraction heat exchange module;

[0047] 111, first condenser-evaporator; 112, first compressor; 113, first regenerator; 114, first expansion valve; 115, first evaporator; 116, second expansion valve; 117, second evaporator; 118, first pipeline; 119, second pipeline;

[0048] 121, third pipeline; 122, second compressor; 123, heat exchanger; 124, second regenerator; 125, third expansion valve;

[0049] 200, ground pipe heat storage unit; 21, heat exchange cooling module; 211, eighth pipeline; 212, valve switch one 212; 213, valve switch two 213;

[0050] 22, heat exchange heating module; 221, ninth pipeline; 222, power pump body one; 223, control valve one; 224, control valve two;

[0051] 23, ground heat storage module;

[0052] 300, organic Rankine cycle unit; 31, power generation cycle module; 32, power generation cooling module;

[0053] 311, fourth pipeline; 312, expander; 313, first heat exchanger; 314, first pump body; 315, second heat exchanger;

[0054] 321, fifth pipeline; 322, first valve; 323, second pump body; 324, cooling tower; 325, second valve;

[0055] 400、Renewable heat source utilizes energy storage unit; 41、First working medium heating module; 42、Second working medium heating module;

[0056] 411、Sixth pipeline; 412、First storage tank; 413、Control valve three; 414、Power pump two; 415、Second storage tank; 416、Control valve four; 417、Water pump;

[0057] 421、Seventh pipeline; 422、Power pump three; 423、Solar heat collector;

[0058] 1001、Debugging outlet water temperature sensor; 1002、Debugging pressure sensor one; 1003、Debugging pressure sensor two; 1004、Debugging pressure sensor three; 1005、Debugging pressure sensor four; 1006、Debugging water flow sensor; 1007、Debugging inlet water temperature sensor.

[0059] The purposes, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0060] It should be understood that the specific embodiments described herein merely exemplify the present application and are not intended to limit the present application.

[0061] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present application.

[0062] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0063] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those skilled in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection claimed by the present application.

[0064] Please refer toFigure 1 、 Figure 2 and Figure 3 The present application provides a Carnot battery system based on cross-season energy storage technology, comprising a cascade heat pump unit 100, a buried pipe heat storage unit 200, an organic Rankine cycle unit 300 and a renewable heat source utilization energy storage unit 400, the input end of the organic Rankine cycle unit 300 is arranged in parallel with the renewable heat source utilization energy storage unit 400, the output end of the organic Rankine cycle unit 300 is arranged in parallel with the buried pipe heat storage unit 200 for heat exchange, the first side of the cascade heat pump unit 100 is connected in parallel to the buried pipe heat storage unit 200, the second side of the cascade heat pump unit 100 is connected in parallel to the renewable heat source utilization energy storage unit 400, the cascade heat pump unit 100 comprises a first heat extraction heat exchange module 11 and a second heat extraction heat exchange module 12, the first heat extraction heat exchange module 11 is used to collect the heat of the external environment and / or the buried pipe heat storage unit 200 (heat exchanger 1231) and exchange heat with the second heat extraction heat exchange module 12, the second heat extraction heat exchange module 12 is used to collect the heat of the first heat extraction heat exchange module 11 and exchange heat with the renewable heat source utilization energy storage unit 400 (water-cooled heat exchanger 123), and the renewable heat source utilization energy storage unit 400 is used to heat and warm the power generation fluid medium at the input end of the organic Rankine cycle unit 300.

[0065] The application provides a Carnot cell system based on a cross-season energy storage technology, which comprises a cascade heat pump unit 100, a ground pipe heat storage unit 200, an organic Rankine cycle unit 300 and a renewable heat source utilization energy storage unit 400, the high-temperature side of the renewable heat source utilization energy storage unit 400 is used for heat exchange with the input end of the organic Rankine cycle unit 300 to increase the temperature of the power generation fluid medium, the heat collection side of the ground pipe heat storage unit 200 is used for heat exchange with the output end of the organic Rankine cycle unit 300 to reduce the temperature of the power generation fluid medium, thereby being beneficial to increase the temperature difference between the input end and the output end of the organic Rankine cycle unit 300 to ensure the power generation efficiency; the cascade heat pump unit 100 comprises a first heat extraction and heat exchange module 11 and a second heat extraction and heat exchange module 12, the first heat extraction and heat exchange module 11 is used for collecting heat of the external environment or the ground pipe heat storage unit 200 and exchanging heat with the second heat extraction and heat exchange module 12, the second heat extraction and heat exchange module 12 is used for collecting heat of the first heat extraction and heat exchange module 11 and exchanging heat with the renewable heat source utilization energy storage unit 400, when the external environment temperature is high in summer, the first heat extraction and heat exchange module 11 can exchange heat with the external environment to provide heat source for the second heat extraction and heat exchange module 12, and the second heat extraction and heat exchange module 12 can exchange heat to be used for heating the power generation fluid medium, when the external environment temperature is low in winter, the first heat extraction and heat exchange module 11 can exchange heat with the ground pipe heat storage unit 200 to provide heat source for the second heat extraction and heat exchange module 12, and the second heat extraction and heat exchange module 12 can exchange heat to be used for heating the power generation fluid medium, thereby avoiding the influence of the external temperature on the energy storage system and ensuring that the energy storage system can always operate efficiently in different seasons. In summer and the transition season, the soil temperature is low and the temperature difference between the external environment and the soil is large, the temperature of the power generation medium fluid passing through the expander 312 is high during the power generation process of the organic Rankine cycle unit 300, and the waste heat at the first heat exchanger 313 cannot be fully utilized, at this time, the waste heat of the power generation medium fluid passing through the expander 312 is stored in the ground pipe heat storage unit 200 through the first heat exchanger 313, in winter, the external environment temperature is low, the temperature of the power generation medium fluid passing through the expander 312 is low during the power generation process of the organic Rankine cycle unit 300, and the efficiency of the organic Rankine cycle module increases with the decrease of the external temperature, at this time, the power generation cycle module 31 and the power generation cooling module 32 can be disconnected to ensure the power generation efficiency. In addition, the efficiency of the cascade heat pump decreases with the decrease of the external temperature. Therefore, in winter, the soil source heat can be used to utilize the waste heat stored in summer and the transition season, at this time, the cascade heat pump unit 100 exchanges heat with the ground pipe heat storage unit 200.

[0066] It can be understood that in summer and transition season, the ambient temperature is high, the soil temperature is low and the temperature difference with the ambient environment is large, the first heat extraction and heat exchange module 11 can exchange heat with the ambient environment to provide heat source for the second heat exchange module, the second heat exchange module is used for heating the fluid medium of the renewable heat source utilization energy storage unit 400, the renewable heat source utilizes the fluid medium of the energy storage unit 400 to exchange heat with the power generation medium fluid to heat it, and in the power generation process of the organic Rankine cycle unit 300, the temperature of the power generation medium fluid passing through the expander 312 is high, and there is waste heat in the first heat exchanger 313 which cannot be fully utilized, at this time, the waste heat of the power generation medium fluid passing through the expander 312 is stored in the buried pipe heat storage unit 200 through the first heat exchanger 313; In winter, the ambient temperature is low, the first heat extraction and heat exchange module 11 can exchange heat with the buried pipe heat storage unit 200 to provide heat source for the second heat exchange module, the second heat exchange module is used for heating the power generation medium fluid, and in the power generation process of the organic Rankine cycle unit 300, the temperature of the power generation medium fluid passing through the expander 312 is low, the efficiency of the organic Rankine cycle module increases with the decrease of the ambient temperature, at this time, the power generation cycle module 31 and the power generation cooling module 32 can be disconnected to ensure the power generation efficiency. In addition, the efficiency of the cascade heat pump decreases with the decrease of the ambient temperature. Therefore, in winter, the soil source heat can be used to utilize the waste heat stored in summer and transition season, at this time, the cascade heat pump unit 100 exchanges heat with the buried pipe heat storage unit 200.

[0067] It can be understood that the renewable heat source utilization energy storage unit 400 includes a first working medium heating module 41 and a second working medium heating module 42, the first working medium heating module 41 includes a second storage tank body 415, the second storage tank body 415 can store the fluid medium reaching the target temperature to heat the power generation fluid medium through the second heat exchanger 315 when needed.

[0068] Further, the first heat extraction and heat exchange module 11 comprises a first condenser-evaporator 111, a first compressor 112, a first regenerator 113, a first expansion valve 114, a first evaporator 115, a second expansion valve 116 and a second evaporator 117, the first compressor 112, the first condenser-evaporator 111, the first regenerator 113, the first expansion valve 114 and the first evaporator 115 are sequentially arranged and communicated through a first pipeline 118, the first condenser-evaporator 111 is between the first compressor 112 and the first regenerator 113, the inlet end and the outlet end of the low-temperature side of the first condenser-evaporator 111 are communicated with the first pipeline 118 respectively, a second pipeline 119 is connected in parallel with the first pipeline 118, a first end of the second pipeline 119 is communicated with the first pipeline 118 and is between the first regenerator 113 and the first expansion valve 114, a second end of the second pipeline 119 is communicated with the first pipeline 118 and is between the first evaporator 115 and the first regenerator 113, the second expansion valve 116 is arranged on the second pipeline 119, the second evaporator 117 is downstream of the second expansion valve 116, and the inlet end and the outlet end of the high-temperature side of the second evaporator 117 are communicated with the second pipeline 119 respectively, the inlet end and the outlet end of the low-temperature side of the second evaporator 117 are communicated with the ground pipe heat storage unit 200 respectively.

[0069] Further, the second heat extraction and heat exchange module 12 comprises a second compressor 122, a heat exchanger 123, a second regenerator 124 and a third expansion valve 125 which are sequentially arranged and communicated through a third pipeline 121, the inlet end and the outlet end of the high-temperature side of the first condenser-evaporator 111 are communicated with the first pipeline 118 respectively, the heat exchanger 123 is between the second compressor and the second regenerator 124, the inlet end and the outlet end of the low-temperature side of the heat exchanger 123 are communicated with the third pipeline 121 respectively, the inlet end and the outlet end of the high-temperature side of the heat exchanger 123 are communicated with the renewable heat source utilization and energy storage unit 400 respectively.

[0070] Further, the organic Rankine cycle unit 300 comprises a power generation cycle module 31 and a power generation cooling module 32, the power generation cycle module 31 comprises an expander 312, a first heat exchanger 313, a first pump body 314 and a second heat exchanger 315 which are sequentially arranged and communicated through a fourth pipeline 311, the inlet end and the outlet end of the high-temperature side of the first heat exchanger 313 are communicated with the fourth pipeline 311 respectively, the inlet end and the outlet end of the low-temperature side of the second heat exchanger 315 are communicated with the fourth pipeline 311 respectively, the power generation cooling module 32 comprises a first valve 322, a second pump body 323 and a cooling tower 324 which are sequentially arranged and communicated through a fifth pipeline 321, the inlet end and the outlet end of the low-temperature side of the first heat exchanger 313 are communicated with the fifth pipeline 321 respectively, the cooling tower 324 is upstream of the first heat exchanger 313, and the cooling tower 324 is connected in parallel with a second valve 325 outside.

[0071] Further, the renewable heat source utilization energy storage unit 400 comprises a first working medium heating module 41 and a second working medium heating module 42, the first working medium heating module 41 comprises a first storage tank body 412, a control valve three 413, a power pump body two 414, a second storage tank body 415, a control valve four 416 and a water pump 417 which are sequentially arranged and sequentially communicated through a sixth pipeline 411, the inlet end and the outlet end of the high-temperature side of the second heat exchanger 315 are communicated with the sixth pipeline 411 respectively, and the second heat exchanger is between the water pump 417 and the second storage tank body 415; the second working medium heating module 42 is connected in parallel on the second storage tank body 415, and the second working medium heating module 42 comprises a power pump body three 422 and a solar heat collector 423 which are sequentially arranged and communicated through a seventh pipeline 421, and the water inlet end and the water outlet end of the seventh pipeline 421 are communicated with two ports of the second storage tank body 415 respectively.

[0072] Understandably, the second working medium heating module 42 is used for preliminarily warming the fluid medium by using solar energy, the second working medium heating module 42 is used for heat exchange with the second heat extraction heat exchange module 12 to secondarily warm the fluid medium, so that the fluid medium reaches the target temperature and is stored in the second storage tank body 415.

[0073] Further, the ground buried pipe heat storage unit 200 comprises a heat exchange cooling module 21, a heat exchange warming module 22 and a ground buried heat storage module 23, the heat exchange cooling module 21 comprises a valve switch one 212 and a valve switch two 213 which are sequentially arranged and communicated through an eighth pipeline 211, two ends of the ground buried heat storage module 23 are communicated with the eighth pipeline 211 respectively and the ground buried heat storage module 23 is between the valve switch one 212 and the valve switch two 213, and the ground buried heat storage module 23 is downstream of the valve switch one 212; the heat exchange warming module 22 comprises a power pump body one 222, a control valve one 223 and a control valve two 224 which are sequentially arranged and communicated through a ninth pipeline 221, two ends of the ground buried heat storage module 23 are communicated with the ninth pipeline 221 respectively and the ground buried heat storage module 23 is between the control valve two 224 and the control valve one 223, the inlet end and the outlet end of the low-temperature side of the second evaporator 117 are communicated with the ninth pipeline 221 respectively, the second evaporator 117 is downstream of the power pump body one 222, and the ground buried heat storage module 23 is upstream of the control valve two 224.

[0074] Understandably, in the application, the renewable heat source utilization energy storage unit 400 utilizes renewable energy, renewable energy provides clean power but its randomness and volatility increase the uncertainty of the power grid, therefore, under this background, the Carnot battery system based on the cross-season energy storage technology is the key to better integration of energy resources and overcoming the volatility.

[0075] Understandably, due to high summer temperature, low winter temperature, temperature changes cause the heat pump cycle process of working fluid heat instability, affect the subsequent compressor work, and further affect the charging efficiency of the energy storage system.

[0076] Please refer to Figure 4 Further, the Carnot battery system based on the cross-season energy storage technology further comprises a debugging outlet water temperature sensor 1001, a debugging pressure sensor one 1002, a debugging pressure sensor two 1003, a debugging pressure sensor three 1004, a debugging pressure sensor four 1005, a debugging water flow sensor 1006, and a debugging inlet water temperature sensor 1007. The debugging inlet water temperature sensor 1007 and the debugging water flow sensor 1006 are arranged on the input side of the high-temperature side of the heat exchanger 123, and the debugging outlet water temperature sensor 1001 is arranged on the output side of the high-temperature side of the heat exchanger 123. The debugging pressure sensor one 1002 is arranged on the output side of the low-temperature side of the heat exchanger 123, the debugging pressure sensor two 1003 is arranged on the input side of the second compressor 122, the debugging pressure sensor three 1004 is arranged on the output side of the low-temperature side of the first condenser evaporator 111, and the debugging pressure sensor four 1005 is arranged on the input side of the low-temperature side of the first condenser evaporator 111.

[0077] In specific implementation, the debugging inlet water temperature sensor 1007 is arranged upstream of the control valve three 413, and the debugging water flow sensor 1006 is arranged downstream of the power pump body two 414.

[0078] The high-temperature input pressure sensor is arranged upstream of the high-temperature system compressor 23, and the high-temperature output pressure sensor is arranged downstream of the high-temperature system compressor 23.

[0079] Further, the present application also provides a Carnot battery control method based on cross-season energy storage technology, which is used for the Carnot battery system based on cross-season energy storage technology described above. When in the air solar heating mode or the soil solar heating mode, the two-point method coarse adjustment and the PI control fine adjustment are adopted to control the temperature so that the target fluid entering the second storage tank body 415 is in the ideal temperature range, and the method specifically comprises the following steps:

[0080] S10, obtaining the current temperature difference between the output temperature of the target fluid and the ideal temperature based on the debugging outlet water temperature sensor 1001. Specifically, the target fluid is the fluid medium stored in the second storage tank body 415, and the output temperature of the fluid medium is obtained through the debugging outlet water temperature sensor 1001.

[0081] S20, judging whether the current temperature difference is within the preset temperature difference range.

[0082] S31, if the current temperature difference is within the preset temperature difference range, the discharge port pressure of the second compressor 122 is obtained as the ideal condensing pressure based on the debugging pressure sensor 1002; specifically, if the current temperature difference is within the preset temperature difference range, the current working condensing pressure in the high-temperature stage heat pump system is obtained as the ideal condensing pressure, that is, the current working condensing pressure in the high-temperature stage heat pump system is obtained as the ideal condensing pressure;

[0083] S32, if the current temperature difference is not within the preset temperature difference range, the ideal condensing pressure is determined according to the high-temperature medium saturation pressure P cse and the high-temperature medium minimum condensing pressure P cmin until the current temperature difference is within the preset temperature difference range; specifically, the high-temperature medium saturation pressure is the saturation pressure of the high-temperature working medium, the high-temperature medium minimum condensing pressure is the minimum condensing pressure of the high-temperature working medium, and the high-temperature working medium is the fluid medium flowing through the second compressor 122 (high-temperature stage heat pump system);

[0084] S40, the target condensing pressure is determined by PI control adjustment of the condensing pressure based on the ideal condensing pressure and the current temperature difference until the current temperature difference is within the ideal temperature difference range;

[0085] S50, S50, the suction port pressure of the first compressor 112 is obtained as the low-temperature medium evaporation pressure P e of the low-temperature working medium based on the debugging pressure sensor four 1005; specifically, the low-temperature medium evaporation pressure P e of the low-temperature working medium in the low-temperature stage heat pump system is determined according to the current environment temperature of the low-temperature stage heat pump system, and the low-temperature working medium is the fluid medium flowing through the first compressor 112 (low-temperature stage heat pump system);

[0086] S60, the formula:

[0087] T m ={[T c T e (η L -1)+ΔT m ] / (η H -1)} 0.5 +ΔT m / 2 is used to calculate the intermediate temperature, where η H =T c C Pw m w (T wos -T wis ) / (T c W H -T e W H ), η L =T c1 [C Pw mw (T wos -T wis )-W H ] / (T c1 W L -T e W L ),

[0088] wherein, T m is the intermediate temperature, T c is the high-temperature medium condensing temperature of the high-temperature working medium, T e is the low-temperature evaporation temperature of the low-temperature working medium, η L is the low-temperature stage heat pump thermodynamic perfection, η H is the high-temperature stage heat pump thermodynamic perfection, ΔT m is the heat exchange temperature difference, C Pw is the constant-pressure specific heat capacity of the fluid medium, m w is the flow of the target fluid, T wos is the ideal temperature of the target fluid, T wi is the entering temperature of the target fluid, W H is the high-temperature stage heat pump compression power consumption, W L is the low-temperature stage heat pump compression power consumption, wherein the high-temperature medium condensing temperature T c corresponds to the target condensing pressure, and the low-temperature medium evaporation temperature T e corresponds to the low-temperature medium evaporation pressure P e ; specifically, T m is the temperature at the position of the first condenser-evaporator, and T c is the temperature at the position of the heat exchanger 123, which is obtained by conversion through the debugging of the pressure sensor 1002, m w is obtained by debugging the flow sensor 1007;

[0089] S70, adjusting the expansion valve of the second compressor 122 in the high-temperature stage heat pump system according to the intermediate temperature.

[0090] In specific implementation, step S32 specifically includes:

[0091] S321, if the current temperature difference is within the preset temperature difference range, obtaining the high-temperature medium saturation pressure P cse (the compressor exhaust port pressure of the second compressor 122) of the high-temperature working medium in the high-temperature stage heat pump system, and obtaining the minimum condensing pressure P cmin (the compressor exhaust port pressure of the second compressor 122) of the high-temperature working medium in the high-temperature stage heat pump system;

[0092] S322, using the formula P cset =(P cmin +P cse) / 2 to obtain the initial value of the current condensing pressure P cset ;

[0093] S323, determine whether the current temperature difference under the initial value of the current condensing pressure P cset is within the preset temperature difference range;

[0094] S324, if the current temperature difference under the initial value of the current condensing pressure P cset is within the preset temperature difference range, determine the initial value of the current condensing pressure P cset as the ideal condensing pressure;

[0095] S325, if the current temperature difference under the initial value of the current condensing pressure P cset is not within the preset temperature difference range, determine whether the current outlet water temperature under the initial value of the current condensing pressure P cset is higher than the ideal temperature,

[0096] S326, if the current outlet water temperature under the initial value of the current condensing pressure P cset is higher than the ideal temperature, update the initial value of the current condensing pressure P cset to the high-temperature medium saturation pressure P cse , and proceed to step S32 to obtain the initial value of the current condensing pressure P cmin based on the high-temperature medium minimum condensing pressure P cse and the updated high-temperature medium saturation pressure P cset ;

[0097] S327, if the current outlet water temperature under the initial value of the current condensing pressure P cset is lower than the ideal temperature, update the initial value of the current condensing pressure P cset to the low-temperature medium minimum condensing pressure P cmin , and proceed to step S32 to obtain the initial value of the current condensing pressure P cse based on the high-temperature medium saturation pressure P cmin and the updated low-temperature medium minimum condensing pressure P cset ;

[0098] Repeat steps S322 to S325 until the ideal condensing pressure is obtained.

[0099] In specific implementation, the refrigerant flow rate of the high-temperature working medium in the high-temperature heat pump system is calculated using the formula m rc =C Pw m w (T wos -T wis ) / (h co1 -h ci1 ) ,

[0100] the temperature difference ΔTN = m rc (h cG1 -h cL1 ) / C Pw m w +T wi -T c1 Calculate the pinch temperature difference, obtain the assumed condensing temperature T N when ΔT c1 = 0, and further determine the assumed condensing pressure P c1 as the minimum condensing temperature T cmin of the high-temperature medium

[0101] where m rc is the refrigerant flow rate, ΔT N is the pinch temperature difference, C Pw is the specific heat capacity of the fluid at constant pressure, m w is the flow rate of the target fluid, T wos is the ideal temperature of the target fluid, T wis is the inlet temperature of the target fluid, h co1 is the enthalpy of the target condenser outlet, h ci1 is the enthalpy of the target condenser inlet, h cG1 is the enthalpy of the refrigerant at the bubble point of the high-temperature condenser, h cL1 is the enthalpy of the refrigerant at the outlet of the high-temperature condenser,

[0102] According to the refrigerant property model, the minimum condensing temperature T cmin of the high-temperature medium is obtained, and the corresponding minimum condensing pressure P cmin of the high-temperature medium is obtained.

[0103] The water outlet temperature control method of the present application relies on cascade control. After the current temperature difference is within the preset temperature difference range, fine adjustment is used to further make the current temperature difference within the ideal temperature difference range. The combination of physical mechanism coarse adjustment and PI control fine adjustment has strong robustness, fast response speed, and strong anti-interference ability. The low-temperature medium evaporation pressure is determined based on the physical mechanism, which can realize accurate and efficient heat extraction of the heat pump and decouple multiple operating parameters. The intermediate temperature is obtained by online collection of operating data and identification of model parameters, and the optimal intermediate temperature is output by relying on the physical model, taking into account the accuracy and interpretability of the model. The intermediate temperature is obtained based on the high-temperature medium condensing temperature and the low-temperature medium evaporation temperature, and the expansion valve of the second compressor is adjusted according to the intermediate temperature, which directly adjusts the expansion valve of the second compressor based on the high-temperature medium condensing temperature and the low-temperature medium evaporation temperature. The technical problem of easy overshoot and oscillation in the temperature adjustment process in the prior art is solved.

[0104] The above embodiments only express several implementation ways of the present application, and the description is specific and detailed, but it should not be understood as a limitation to the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A Carnot cell system based on cross-seasonal energy storage technology, characterized in that, a cascade heat pump unit, a ground pipe heat storage unit, an organic Rankine cycle unit, and a renewable heat source utilization energy storage unit are included, the input end of the organic Rankine cycle unit is arranged in parallel with the renewable heat source utilization energy storage unit, the output end of the organic Rankine cycle unit is arranged in parallel with the ground pipe heat storage unit for heat exchange, the first side of the cascade heat pump unit is connected in parallel to the ground pipe heat storage unit, and the second side of the cascade heat pump unit is connected in parallel to the renewable heat source utilization energy storage unit; the cascade heat pump unit includes a first heat extraction heat exchange module and a second heat extraction heat exchange module, the first heat extraction heat exchange module is used to collect heat from the external environment or the ground pipe heat storage unit and exchange heat with the second heat extraction heat exchange module, the second heat extraction heat exchange module is used to collect heat from the first heat extraction heat exchange module and exchange heat with the renewable heat source utilization energy storage unit, and the renewable heat source utilization energy storage unit is used to heat and warm the power generation fluid medium at the input end of the organic Rankine cycle unit; the organic Rankine cycle unit includes a power generation cycle module and a power generation cooling module; the power generation cycle module includes an expander, a first heat exchanger, a first pump body, and a second heat exchanger arranged in sequence and connected by a fourth pipeline, the inlet end and the outlet end of the high-temperature side of the first heat exchanger are respectively connected with the fourth pipeline, the inlet end and the outlet end of the low-temperature side of the second heat exchanger are respectively connected with the fourth pipeline, the power generation cooling module includes a first valve, a second pump body, and a cooling tower arranged in sequence and connected by a fifth pipeline, the inlet end and the outlet end of the low-temperature side of the first heat exchanger are respectively connected with the fifth pipeline, the cooling tower is upstream of the first heat exchanger, and a second valve is connected in parallel outside the cooling tower.

2. The Carnot cell system based on cross-seasonal energy storage technology according to claim 1, characterized in that, the first heat extraction heat exchange module includes a first condenser-evaporator, a first compressor, a first regenerator, a first expansion valve, a first evaporator, a second expansion valve, and a second evaporator, the first compressor, the first condenser-evaporator, the first regenerator, the first expansion valve, and the first evaporator are arranged in sequence and connected by a first pipeline, the first condenser-evaporator is between the first compressor and the first regenerator, and the inlet end and the outlet end of the low-temperature side of the first condenser-evaporator are respectively connected with the first pipeline; a second pipeline is connected in parallel to the first pipeline, the first end of the second pipeline is connected with the first pipeline and is between the first regenerator and the first expansion valve, the second end of the second pipeline is connected with the first pipeline and is between the first evaporator and the first regenerator, the second expansion valve is arranged on the second pipeline, and the second evaporator is downstream of the second expansion valve and the inlet end and the outlet end of the high-temperature side of the second evaporator are respectively connected with the second pipeline; the inlet end and the outlet end of the low-temperature side of the second evaporator are respectively connected with the ground pipe heat storage unit.

3. The trans-seasonal energy storage technology based Carnot cell system according to claim 2, wherein the second heat extraction and heat exchange module comprises a second compressor, a heat exchanger, a second regenerator and a third expansion valve arranged in sequence and communicated by a third pipeline, the inlet end and the outlet end of the high-temperature side of the first condenser-evaporator are communicated with the first pipeline respectively; the heat exchanger is between the second compressor and the second regenerator, the inlet end and the outlet end of the low-temperature side of the heat exchanger are communicated with the third pipeline respectively, and the inlet end and the outlet end of the high-temperature side of the heat exchanger are communicated with the renewable heat source and energy storage unit.

4. The trans-seasonal energy storage technology based Carnot cell system according to any one of claims 1 to 3, wherein the renewable heat source and energy storage unit comprises a first working medium heating module and a second working medium heating module, the first working medium heating module comprises a first storage tank, a control valve three, a power pump two, a second storage tank, a control valve four and a water pump arranged in sequence and communicated by a sixth pipeline in sequence, the inlet end and the outlet end of the high-temperature side of the second heat exchanger are communicated with the sixth pipeline respectively, and the second heat exchanger is between the water pump and the second storage tank; the second working medium heating module is connected in parallel to the second storage tank, and the second working medium heating module comprises a power pump three and a solar heat collector arranged in sequence and communicated by a seventh pipeline, and the water inlet end and the water outlet end of the seventh pipeline are communicated with two ports of the second storage tank respectively.

5. The trans-seasonal energy storage technology based Carnot cell system according to any one of claims 2 or 3, wherein the ground pipe heat storage unit comprises a heat exchange and cooling module, a heat exchange and heating module and a ground heat storage module, the heat exchange and cooling module comprises a valve switch one and a valve switch two arranged in sequence and communicated by an eighth pipeline, two ends of the ground heat storage module are communicated with the eighth pipeline respectively, and the ground heat storage module is between the valve switch one and the valve switch two, and the ground heat storage module is downstream of the valve switch one; the heat exchange and heating module comprises a power pump one, a control valve one and a control valve two arranged in sequence and communicated by a ninth pipeline, two ends of the ground heat storage module are communicated with the ninth pipeline respectively, and the ground heat storage module is between the control valve two and the control valve one, the inlet end and the outlet end of the low-temperature side of the second evaporator are communicated with the ninth pipeline respectively, the second evaporator is downstream of the power pump one, and the ground heat storage module is upstream of the control valve two. including a single power generation mode, if the temperature difference between the input temperature and the output temperature of the power generation medium fluid is not greater than a first threshold value, the trans-seasonal energy storage technology based Carnot cell system is controlled to be in a single power generation mode, and in the single power generation mode, the fluid medium in the power generation and cooling module is in a static state; ​ 6. A Carnot cell control method based on cross-seasonal energy storage technology for the Carnot cell system based on cross-seasonal energy storage technology according to any one of claims 1 to 5, characterized in that, ​ ​ The power generation-soil source condensing heat recovery mode is controlled to be in the power generation-soil source condensing heat recovery mode when a temperature difference between an input temperature and an output temperature of the power generation medium fluid is not greater than a first threshold value, and the fluid medium in the power generation cooling module exchanges heat through the first heat exchanger in the power generation-soil source condensing heat recovery mode, and in turn, the power generation waste heat is stored in the ground pipe heat storage unit; The composite heating mode is an air-solar heating mode in which an air source heating mode and a solar heating mode are fused, or the composite heating mode is a soil-solar heating mode in which a soil source heating mode and a solar heating mode are fused, or the composite heating mode is a single air source heating mode, or the composite heating mode is a single soil source heating mode; When the air-solar heating mode is adopted, the first working medium heating module of the renewable heat source utilization energy storage unit heats the fluid medium by using solar energy, the first heat taking and exchanging module is used to collect heat from the external environment and exchange heat with the second heat taking and exchanging module, and the second heat taking and exchanging module is used to collect heat from the first heat taking and exchanging module and exchange heat with the fluid medium heated by the renewable heat source utilization energy storage unit. When the soil-solar heating mode is adopted, the first working medium heating module of the renewable heat source utilization energy storage unit heats the fluid medium by using solar energy, the first heat taking and exchanging module is used to collect heat from the ground pipe heat storage unit and exchange heat with the second heat taking and exchanging module, and the second heat taking and exchanging module is used to collect heat from the first heat taking and exchanging module and exchange heat with the fluid medium heated by the renewable heat source utilization energy storage unit.

7. The control method of the Carnot cell based on the cross-season energy storage technology according to claim 6, wherein when the single air source heating mode is adopted, the first heat taking and exchanging module is used to collect heat from the external environment and exchange heat with the second heat taking and exchanging module, and the second heat taking and exchanging module is used to collect heat from the first heat taking and exchanging module and exchange heat with the fluid medium heated by the renewable heat source utilization energy storage unit. When the single soil source heating mode is adopted, the first heat taking and exchanging module is used to collect heat from the ground pipe heat storage unit and exchange heat with the second heat taking and exchanging module, and the second heat taking and exchanging module is used to collect heat from the first heat taking and exchanging module and exchange heat with the fluid medium heated by the renewable heat source utilization energy storage unit.

8. The control method of the Carnot cell based on the cross-season energy storage technology according to claim 7, wherein when the air-solar heating mode or the soil-solar heating mode is adopted, a two-step method of coarse adjustment by bisection and fine adjustment by PI control is adopted to control the temperature of the target fluid entering the second storage tank body in the ideal temperature range, and the method comprises the following steps: S10, obtaining a current temperature difference between an output temperature of the target fluid and an ideal temperature based on the debugging outlet water temperature sensor; S20, judging whether the current temperature difference is within a preset temperature difference range; ​ ​ S31, if the current temperature difference is within the preset temperature difference range, based on the debugging pressure sensor to obtain the ideal condensing pressure of the second compressor; S32, if the current temperature difference is not within the preset temperature difference range, determining an ideal condensing pressure according to a high-temperature medium saturated pressure P cseand a high-temperature medium minimum condensing pressure P cmin The ideal condensing pressure is determined until the current temperature difference is within the preset temperature difference range, wherein the high-temperature medium saturated pressure is a saturated pressure of a high-temperature working medium, and the high-temperature working medium is a fluid medium flowing through the second compressor. S40, based on the ideal condensing pressure and the current temperature difference, PI control adjustment is performed on the condensing pressure to determine the target condensing pressure, until the current temperature difference is within the ideal temperature difference range; S50, acquire the suction port pressure of the first compressor as the low-temperature medium evaporation pressure of the low-temperature working medium based on the commissioning of the pressure sensor four P e; S60, obtain the intermediate temperature; S70, adjust the expansion valve of the second compressor in the high-temperature stage heat pump system according to the intermediate temperature.

9. The control method of the Carnot cell based on the cross-season energy storage technology according to claim 8, characterized in that, The formula is: calculating an intermediate temperature, wherein, ， ， wherein, T m is an intermediate temperature, T c is a high-temperature medium condensing temperature of the high-temperature working medium, T e is a low-temperature evaporation temperature of the low-temperature working medium, η L is a low-temperature stage heat pump thermodynamic perfection, η H is a high-temperature stage heat pump thermodynamic perfection, Δ T m is a heat exchange temperature difference, C Pw is a constant-pressure specific heat capacity of the fluid medium, m w is a flow rate of the target fluid, T wos is an ideal temperature of the target fluid, T wi is an inlet temperature of the target fluid, W H is a high-temperature stage heat pump compression power consumption, W L is a low-temperature stage heat pump compression power consumption, wherein the high-temperature medium condensing temperature T c corresponds to a target condensing pressure, the low-temperature medium evaporation temperature T e corresponds to the low-temperature medium evaporation pressure P e; wherein the low-temperature working medium is a fluid medium flowing through the first compressor.

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