Coupling photo-thermal Carnot cell combined cooling heating and power supply system and method

Abstract

The system comprises a cascade heat pump module, an organic Rankine cycle power generation module and a photo-thermal heat collection module, wherein the cascade heat pump module, the organic Rankine cycle power generation module and the photo-thermal heat collection module are in coupled connection through an evaporative condenser. The cascade heat pump module comprises a low-temperature-stage heat pump subsystem and a high-temperature-stage heat pump subsystem, and the low-temperature-stage subsystem is driven by power of a power grid, improves low-grade heat energy and supplies cold to a building; the high-temperature subsystem further heats the heat energy, and the heat energy is stored in a first high-temperature heat storage tank; the organic Rankine cycle power generation module generates power through heat energy stored in the first high-temperature heat storage tank and the second high-temperature heat storage tank. The photo-thermal heat collection module collects and stores solar energy through the medium-temperature heat storage tank and the second high-temperature heat storage tank. Through multi-module cooperative operation and graded heat storage design, multi-energy complementation and gradient utilization of electric energy and solar energy are achieved, and the photo-thermal coupling efficiency, the system operation flexibility and the multi-energy combined supply adaptability are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy storage technology, in particular to a kind of coupling photothermal Carnot cell combined heat and power system and method. BACKGROUND

[0002] Energy storage technology is the inevitable choice to support power supply and demand balance and absorb renewable energy, which is of great significance to China's construction of "clean, low-carbon, safe and efficient" energy system. Carnot cell is a new energy storage technology based on two temperature zones, which uses heat pump to convert electrical energy into thermal energy, and then uses heat engine to realize heat-electricity conversion. On the one hand, it can store solar energy, geothermal energy and wind energy during the low electricity consumption period, and put it into the grid after heat-electricity conversion during the high electricity consumption period, to realize peak load shifting and supply and demand balance regulation. On the other hand, it can integrate various grade heat or cold energy into micro energy grid system to realize multi-energy supply and meet different forms of energy demand on user side.

[0003] From the development of China's energy system structure, the installed capacity of renewable energy represented by distributed photovoltaic has expanded rapidly, and problems such as system peak shaving difficulty, local overload of distribution network and reduction of system safety margin have occurred, so it is urgent to develop a storage and generation integrated collaborative solution of multi-type energy supply of electricity, heat and cold. Distributed energy system structure is complex, with various equipment, and is affected by comprehensive influence of user side cold, heat and electricity load, and mostly deviates from design operating condition. At present, there is still a lack of system integrating multi-type equipment and adapting to flexible operation under all operating conditions.

[0004] Therefore, it is urgent to develop a kind of coupling photothermal Carnot cell combined heat and power system and method, which can improve the coupling photothermal capacity of Carnot cell, flexibly regulate load and improve the adaptability of multi-energy supply. SUMMARY

[0005] The purpose of the present application is to provide a kind of coupling photothermal Carnot cell combined heat and power system and method, to solve the technical problems of weak coupling photothermal capacity of existing Carnot cell, difficult flexible regulation of load and poor adaptability of multi-energy supply.

[0006] To achieve the above-mentioned purpose, in the first aspect, the present application provides a kind of coupling photothermal Carnot cell combined heat and power system, comprising:

[0007] The cascade heat pump module comprises a low-temperature stage heat pump subsystem and a high-temperature stage heat pump subsystem coupled by an evaporative condenser; the low-temperature stage heat pump subsystem is used to drive the power grid power to improve the low-grade heat energy to high-grade heat energy, and provide cold energy for the building; the high-temperature stage heat pump subsystem is used to further heat the heat energy provided by the low-temperature stage heat pump subsystem, and store the high-grade heat energy in the first high-temperature heat storage tank;

[0008] An organic Rankine cycle power generation module connected with the high-temperature stage heat pump subsystem through the first high-temperature heat storage tank, for generating power by using the heat energy stored in the first high-temperature heat storage tank and the second high-temperature heat storage tank;

[0009] A photothermal heat collection module connected with the high-temperature stage heat pump subsystem and the organic Rankine cycle power generation module through the medium-temperature heat storage tank and the second high-temperature heat storage tank, for collecting solar energy and storing the heat energy in the medium-temperature heat storage tank and the second high-temperature heat storage tank.

[0010] As a further improvement of the above-mentioned scheme, the low-temperature stage heat pump subsystem comprises:

[0011] A low-temperature cold storage tank for storing the cold storage working medium after providing cooling for the building;

[0012] A first working medium pump connected to the outlet of the low-temperature cold storage tank, for conveying the cold storage working medium;

[0013] A first low-temperature evaporator, the hot side inlet of which is connected to the outlet of the first working medium pump, and the hot side outlet of which is connected to the inlet of the low-temperature cold storage tank, for heat exchange between the cold storage working medium and the circulating working medium;

[0014] A first compressor, the inlet of which is connected to the cold side outlet of the low-temperature regenerator, for compressing the low-temperature and low-pressure circulating working medium into a medium-temperature and medium-pressure state;

[0015] A first low-temperature stage condenser, the inlet of which is connected to the outlet of the first compressor, for heat exchange between the medium-temperature circulating working medium and an external medium;

[0016] An evaporative condenser, the hot side inlet of which is connected to the outlet of the first compressor, for heat exchange between the low-pressure stage heat pump circulating working medium and the high-pressure stage heat pump circulating working medium;

[0017] A low-temperature regenerator, the cold side inlet of which is connected to the cold side outlet of the first low-temperature evaporator, for heat exchange between the low-temperature circulating working medium and the medium-temperature circulating working medium; and the hot side inlet of which is connected to the outlet of the first low-temperature stage condenser and the hot side outlet of the evaporative condenser through a three-way valve.

[0018] As a further improvement of the above-mentioned scheme, the low-temperature stage heat pump subsystem further comprises a second low-temperature evaporator, a first throttling valve and a second throttling valve;

[0019] The inlets of the two throttling valves are connected to the hot side outlet of the low-temperature regenerator, for reducing the temperature and pressure of the medium-temperature circulating working medium to a low-temperature and low-pressure state; the outlet of the first throttling valve is connected to the cold side inlet of the first low-temperature evaporator, and the outlet of the second throttling valve is connected to the inlet of the second low-temperature evaporator;

[0020] The outlet of the second low-temperature evaporator is connected to the cold side inlet of the low-temperature regenerator, for taking heat from the environment.

[0021] As a further improvement of the above-mentioned scheme, the low-temperature stage heat pump subsystem further comprises a second low-temperature stage condenser, the inlet of which is connected to the outlet of the first low-temperature stage condenser and the outlet of the evaporative condenser through a three-way valve, and the outlet of which is connected to the hot side inlet of the low-temperature regenerator.

[0022] As a further improvement of the above-mentioned scheme, the low-temperature stage heat pump subsystem further comprises:

[0023] a first three-way valve arranged at the outlet of the first compressor and connected to the inlet of the first low-temperature stage condenser and the hot side inlet of the evaporative condenser, respectively;

[0024] a second three-way valve arranged at the outlet of the first low-temperature stage condenser and connected to the hot side inlet of the low-temperature regenerator and the inlet of the second low-temperature stage condenser, respectively;

[0025] a third three-way valve arranged at the outlet of the evaporative condenser and connected to the inlet of the second low-temperature stage condenser and the second three-way valve, respectively.

[0026] As a further improvement of the above-mentioned scheme, the low-temperature cold storage tank uses glycol water solution as the cold storage medium; the medium-temperature heat storage tank and the first high-temperature heat storage tank use pressurized water as the heat storage medium;

[0027] the second high-temperature heat storage tank uses solid-liquid phase change material as the heat storage medium.

[0028] As a further improvement of the above-mentioned scheme, the high-temperature stage heat pump subsystem comprises:

[0029] an evaporative condenser, the cold side outlet of which is connected to the cold side inlet of the high-temperature regenerator, for realizing heat energy transfer between the low-pressure stage and the high-pressure stage heat pump subsystems;

[0030] a high-temperature regenerator, the cold side outlet of which is connected to the inlet of the second compressor, for heat exchange between the medium-temperature circulating working medium and the high-temperature circulating working medium;

[0031] a second compressor, the outlet of which is connected to the hot side inlet of the high-temperature condenser, for compressing the medium-temperature low-pressure circulating working medium into a high-temperature high-pressure state;

[0032] a high-temperature condenser, the hot side outlet of which is connected to the hot side inlet of the high-temperature regenerator, for heat exchange between the high-temperature circulating working medium and the heat storage working medium;

[0033] a high-temperature evaporator, the cold side inlet of which is connected to the hot side outlet of the high-temperature regenerator, and the cold side outlet of which is connected to the cold side inlet of the high-temperature regenerator, for heat exchange between the medium-temperature heat source and the circulating working medium;

[0034] a medium-temperature heat storage tank, the inlet of which is connected to the hot side outlet of the high-temperature evaporator, and the outlet of which is connected to the hot side inlet of the high-temperature evaporator through a second working medium pump, for storing medium-grade heat energy;

[0035] A first high-temperature heat storage tank, an inlet of which is connected to an outlet of the high-temperature condenser cold side, and an outlet of which is connected to an inlet of the high-temperature condenser cold side through a third working medium pump, for storing high-grade heat energy.

[0036] As a further improvement of the above-mentioned scheme, the high-temperature stage heat pump subsystem further comprises a third throttling valve and a fourth throttling valve, the third throttling valve being connected between the high-temperature regenerator hot side outlet and the evaporative condenser cold side inlet, and the fourth throttling valve being connected between the high-temperature regenerator hot side outlet and the high-temperature evaporator cold side inlet, for reducing the temperature and pressure of the high-temperature circulating working medium to a medium-temperature low-pressure state.

[0037] As a further improvement of the above-mentioned scheme, the high-temperature stage heat pump subsystem has two operating modes:

[0038] When the third throttling valve is opened, the system operates in a cascade mode, and receives heat energy provided by the low-pressure stage heat pump subsystem through the evaporative condenser;

[0039] When the fourth throttling valve is opened, the system operates in an independent mode, and obtains heat energy from the medium-temperature heat storage tank through the high-temperature evaporator.

[0040] As a further improvement of the above-mentioned scheme, the organic Rankine cycle power generation module comprises:

[0041] A first high-temperature heat storage tank, for storing high-grade heat energy from the high-temperature stage heat pump subsystem;

[0042] An oil-water heat exchanger, a hot side inlet of which is connected to an outlet of the first high-temperature heat storage tank, and a hot side outlet of which is connected to an inlet of the first high-temperature heat storage tank, for heat exchange between the high-temperature heat storage working medium and the heat conducting oil;

[0043] A second high-temperature heat storage tank, an inlet of which is connected to a cold side outlet of the oil-water heat exchanger, for storing high-grade heat energy from the photo-thermal heat collection module;

[0044] An ORC evaporator, a hot side inlet of which is connected to an outlet of the second high-temperature heat storage tank, for heat exchange between the heat conducting oil and the organic working medium;

[0045] An expander, an inlet of which is connected to a cold side outlet of the ORC evaporator, for expansion of the high-temperature high-pressure organic working medium to generate power;

[0046] An ORC condenser, an inlet of which is connected to an outlet of the expander, for condensation of the expanded organic working medium;

[0047] A fifth working medium pump, connected between an outlet of the ORC condenser and a cold side inlet of the ORC evaporator, for pressure increasing circulation of the organic working medium;

[0048] A fourth working medium pump, an inlet of which is connected to a hot side outlet of the ORC evaporator, and an outlet of which is connected to a cold side inlet of the oil-water heat exchanger and an inlet of the second high-temperature heat storage tank through a three-way valve, for circulation of the heat conducting oil.

[0049] As a further improvement of the above-mentioned solution, the organic Rankine cycle power generation module further comprises:

[0050] A fourth three-way valve is arranged at the outlet of the fourth working medium pump, and is used for selecting the flow direction of the heat transfer oil;

[0051] A fifth three-way valve is arranged at the outlet of the second high-temperature heat storage tank, and is used for selecting the heat source input to the ORC evaporator;

[0052] A sixth three-way valve is arranged at the cold side inlet of the oil-water heat exchanger, and is used for receiving the heat transfer oil from the fourth working medium pump.

[0053] As a further improvement of the above-mentioned solution, the organic Rankine cycle power generation module has a dual heat source input mode:

[0054] When the fifth three-way valve is connected to the second high-temperature heat storage tank and the ORC evaporator, the system preferentially uses the high-grade heat energy stored by the light-heat collection module;

[0055] When the fifth three-way valve is switched to other positions, the system uses the heat energy converted by the first high-temperature heat storage tank through the oil-water heat exchanger.

[0056] As a further improvement of the above-mentioned solution, the light-heat collection module comprises:

[0057] A solar collector is used to collect solar energy and heat the circulating working medium;

[0058] A sixth working medium pump is connected between the outlet of the second high-temperature heat storage tank and the inlet of the solar collector, and is used to drive the circulation of the heat transfer oil;

[0059] An electric heater is connected to the outlet of the solar collector, and is used to supplement the heat of the heat transfer oil when the light is insufficient;

[0060] A medium-temperature heat storage tank is connected to the outlet of the solar collector, and is used to store medium-grade heat energy;

[0061] A second high-temperature heat storage tank is connected to the outlet of the electric heater, the outlet of the medium-temperature heat storage tank, and the outlet of the solar collector, respectively, and is used to store high-grade heat energy.

[0062] As a further improvement of the above-mentioned solution, the light-heat collection module further comprises:

[0063] A seventh three-way valve is arranged at the outlet of the solar collector, and is used for selecting the flow direction of the heat transfer oil to the electric heater or direct storage;

[0064] An eighth three-way valve is arranged at the outlet of the solar collector, and is used for selecting the flow direction of the heat transfer oil to the medium-temperature heat storage tank or the second high-temperature heat storage tank.

[0065] As a further improvement of the above-mentioned scheme, the photo-thermal heat collection module has three operating modes:

[0066] When the light is sufficient, the heat conduction oil is directly stored in the second high-temperature heat storage tank after being heated by the solar heat collector;

[0067] When the light is insufficient but can be partially utilized, the heat conduction oil is preheated by the solar heat collector and then enters the electric heater for re-heating, and is then stored in the second high-temperature heat storage tank;

[0068] When medium-grade heat energy is needed, part of the heat conduction oil can be diverted to the medium-temperature heat storage tank for storage.

[0069] As a further improvement of the above-mentioned scheme, the circulating working medium used in the low-temperature stage heat pump subsystem is R1234ze(E); the circulating working medium used in the high-temperature stage heat pump subsystem and the organic Rankine cycle power generation module is R1233zd(E); the circulating working medium used in the photo-thermal heat collection module is heat conduction oil; and the working medium used for heat transfer between the oil-water heat exchanger and the ORC evaporator is heat conduction oil.

[0070] In a second aspect, the application also provides a method for operating a coupled photo-thermal Carnot cell combined heat and power system as described in the first aspect, which steps include: an energy storage stage and an energy release stage:

[0071] The energy storage stage includes operating a cascade heat pump cycle and a photo-thermal heat collection cycle;

[0072] In the cascade heat pump cycle, the grid surplus power drives the first compressor and the second compressor, the low-temperature stage heat pump subsystem supplies heat to the high-temperature stage heat pump subsystem through the evaporative condenser after upgrading the low-grade heat energy, and the high-grade heat energy generated by the high-temperature stage heat pump subsystem is stored in the first high-temperature heat storage tank;

[0073] In the photo-thermal heat collection cycle, the solar heat collector collects solar energy to heat the heat conduction oil, and stores the heat in the medium-temperature heat storage tank and / or the second high-temperature heat storage tank;

[0074] The energy release stage operates an organic Rankine cycle power generation; the heat energy stored in the first high-temperature heat storage tank and the second high-temperature heat storage tank is used to heat the working medium of the organic Rankine cycle power generation module, driving the expander to generate power.

[0075] As a further improvement of the above-mentioned scheme, the low-temperature stage heat pump subsystem and the high-temperature stage heat pump subsystem can independently operate according to the load demand:

[0076] When the low-temperature stage heat pump subsystem operates independently, the first low-temperature evaporator can be selectively enabled for cooling or the second low-temperature evaporator can be selectively enabled to take heat from the environment, and the first low-temperature stage condenser and the second low-temperature stage condenser can be selectively enabled for heating.

[0077] When the high-temperature stage heat pump subsystem operates independently, the generated high-grade heat energy is stored in the first high-temperature heat storage tank.

[0078] As a further improvement of the above scheme, when the light is sufficient, the solar energy is preferentially converted into heat energy and stored in the second high-temperature heat storage tank.

[0079] When the light is insufficient, the electric heater is enabled to supplement the heat of the heat-conducting oil to meet the energy storage temperature requirement.

[0080] As a further improvement of the above scheme, the heat energy stored in the medium-temperature heat storage tank, the first high-temperature heat storage tank and the second high-temperature heat storage tank can be supplied according to external requirements.

[0081] Due to the above technical scheme, the present application has the following beneficial effects:

[0082] The present application provides a kind of coupled photothermal Carnot cell combined heat and power system, through innovative system architecture and operating strategy, effectively solve the technical problems such as weak coupling photothermal ability of existing Carnot cell system, inflexible load regulation and poor adaptability of multi-energy supply.Specifically, through the coupling design of low-temperature stage and high-temperature stage subsystems in the cascade heat pump module, with the control of double-evaporator structure and three-way valve group, flexible switching of operating mode is realized: the low-temperature stage heat pump subsystem adopts double-evaporator design (first low-temperature evaporator and second low-temperature evaporator), which can select cooling mode or environment heat extraction mode according to demand; through three-way valve group, parallel optional connection of low-temperature stage condenser and evaporative condenser is realized, which can select heating or energy storage mode according to need; the high-temperature stage heat pump subsystem can be flexibly switched between cascade mode and independent mode through double-throttle valve design; this multi-mode operation capability enables the system to adapt to load changes in different seasons and different time periods, significantly improving the adaptability of cold, heat and electricity multi-energy supply.

[0083] Through the collaborative design of photothermal heat collection module and other modules of the system, multi-stage efficient utilization of solar energy is realized.The photothermal heat collection module adopts double-stage heat storage design (medium-temperature heat storage tank and second high-temperature heat storage tank), which can select the optimal heat storage strategy according to solar irradiance; the high-temperature stage heat pump subsystem can utilize the heat energy in the medium-temperature heat storage tank through high-temperature evaporator to further improve the grade of heat energy; the organic Rankine cycle power generation module can simultaneously utilize the heat energy of the first high-temperature heat storage tank (heat pump energy storage) and the second high-temperature heat storage tank (photothermal energy storage) to realize multi-source collaborative power generation; this cascade utilization and collaborative operation design significantly improves the photothermal coupling efficiency and overall energy utilization rate.

[0084] In addition, the system also significantly improves the grid regulation capability. In the low valley of the grid load, the cheap electricity can be used to drive the cascade heat pump cycle to store the electric energy into heat energy. In the peak of the grid load, the stored heat energy can be converted into electric energy by the organic Rankine cycle to feedback to the grid. The photothermal heat collection module can effectively absorb the unstable solar energy resources and realize stable output through the heat storage system. The system can quickly respond according to the demand of the grid to realize the functions of peak clipping and valley filling and frequency regulation. This design not only improves the stability of the grid operation, but also promotes the efficient absorption and utilization of renewable energy.

[0085] Furthermore, the system adopts the cascade heat pump design, which can significantly reduce the energy consumption and operation cost compared with the single-stage heat pump system. The introduction of the photothermal heat collection module reduces the dependence on traditional energy and improves the economic efficiency of the system. The multi-module collaborative design and redundant configuration improve the reliability and stability of the system operation.

[0086] Through the systematic innovation design and the cooperation of multiple modules, the present application realizes the efficient coupling of Carnot battery and photothermal system, and provides an effective technical solution for building a clean, efficient and flexible energy system.

[0087] 2. The present application provides a kind of operation method of coupling photothermal Carnot battery combined heat and power system, through innovative operation strategy and control logic, effectively solve the technical problems of single operation mode, inflexible load regulation and poor adaptability of multi-energy supply of existing Carnot battery system. Specifically, first, through the phased operation strategy and modular control, the high flexibility of system operation is realized. The phased operation strategy of energy storage stage and energy release stage can flexibly switch the operation mode according to the demand of grid load;The low-temperature heat pump subsystem can selectively enable the first low-temperature evaporator for cooling or enable the second low-temperature evaporator to take heat from the environment, realizing the flexible switching of cooling mode and heat taking mode;The high-temperature heat pump subsystem can select cascade mode or independent mode operation, and select the optimal operation strategy according to the heat source condition;This multi-mode operation capability enables the system to adapt to the load change demand of different seasons and different time periods.

[0088] Secondly, through the optimization of operation process and collaborative control strategy, the cascade efficient utilization of energy is realized. In the energy storage stage, the surplus electric energy of the grid is used to drive the cascade heat pump cycle to store the low-grade heat energy into high-grade heat energy;In the photothermal heat collection cycle, intelligent storage strategy is selected according to the light condition: high-temperature heat energy is directly stored when the light is sufficient, and the electric heater is used for heating when the light is insufficient;In the energy release stage, the organic Rankine cycle can utilize the heat energy of the first high-temperature heat storage tank (heat pump energy storage) and the second high-temperature heat storage tank (photothermal energy storage) at the same time to realize multi-source collaborative power generation;This optimized operation strategy significantly improves the overall energy utilization efficiency.

[0089] Further, through intelligent operation control, the system has excellent power grid service capability. During the low valley of power grid load, the cascade heat pump cycle is preferentially operated to consume excess power and realize conversion and storage of electric energy into heat energy; during the peak of power grid load, the organic Rankine cycle is operated to generate power and convert stored heat energy into electric energy to feedback to the power grid; according to the solar radiation condition, the operation strategy of the photo-thermal heat collection cycle is intelligently adjusted to maximize the consumption of solar energy resources. This operation mode not only improves the stability of power grid operation, but also promotes the efficient utilization of renewable energy.

[0090] Then, through modular independent operation design, each subsystem can be independently operated to improve the reliability and availability of the system; according to external conditions, the optimal operation mode is intelligently selected to reduce the energy consumption and cost of system operation; through time-sharing operation strategy, the low valley electricity price is fully utilized to significantly reduce the operation cost; through multi-heat source collaborative design and intelligent control strategy, the dependence on external energy is reduced.

[0091] Through the innovative operation method and intelligent control strategy, the present application can maximize the operation efficiency of the Carnot cell system and minimize the operation cost, effectively solves the technical problems of single operation mode and inflexible load regulation in the prior art, and provides an effective technical solution for constructing an efficient, flexible and economical energy system. BRIEF DESCRIPTION OF DRAWINGS

[0092] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the drawings shown.

[0093] Figure 1 The structure of the coupled photo-thermal Carnot cell combined heat and power system is shown in the structural schematic diagram of the present application.

[0094] Reference signs:

[0095] 1, low temperature cold storage tank; 2, first working medium pump; 3, first low temperature evaporator; 4, second low temperature evaporator; 5, low temperature recuperator; 6, first compressor; 7, first low temperature stage condenser; 8, evaporative condenser; 9, second low temperature stage condenser; 10, high temperature evaporator; 11, high temperature recuperator; 12, second working medium pump; 13, medium temperature heat storage tank; 14, second compressor; 15, high temperature condenser; 16, third working medium pump; 17, first high temperature heat storage tank; 18, oil-water heat exchanger; 19, second high temperature heat storage tank; 20, ORC evaporator; 21, fourth working medium pump; 22, expander; 23, ORC condenser; 24, fifth working medium pump; 25, sixth working medium pump; 26, solar heat collector; 27, electric heater; 301, first throttle valve; 302, second throttle valve; 303, third throttle valve; 304, fourth throttle valve; 401, first three-way valve; 402, second three-way valve; 403, third three-way valve; 404, fourth three-way valve; 405, fifth three-way valve; 406, sixth three-way valve; 407, seventh three-way valve; 408, eighth three-way valve.

[0096] 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

[0097] The technical solutions in the embodiments of the present application will be clearly and completely described below 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 work fall within the scope of protection of the present application.

[0098] It should be noted that all the directional indications (such as up, down, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0099] In addition, the descriptions such as "first", "second" and the like in the present application are 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 defined as "first", "second" can explicitly or implicitly include at least one of the features.

[0100] Moreover, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0101] Embodiment 1

[0102] As Figure 1 shown, the present application provides a light-heat coupled Carnot cell combined cooling, heating and power system. In view of the problems of the existing Carnot cell, such as insufficient light-heat coupling capacity, low load regulation flexibility and poor multi-energy supply adaptability, through the integrated design of the cascade heat pump module, organic Rankine cycle power generation module and light-heat heat collection module, the effective integration of light-heat resources and the cascade utilization of system energy are realized, so as to improve the overall energy conversion efficiency and enhance the response capability to different load demands.

[0103] The cascade heat pump module includes a low-temperature level heat pump subsystem and a high-temperature level heat pump subsystem, which are coupled and connected through an evaporative condenser 8. The low-temperature level heat pump subsystem utilizes grid power to drive the low-grade heat energy in the environment to a higher temperature, while providing cold output for the building. This design not only improves the utilization rate of low-grade heat sources, but also stores excess energy during periods of sufficient power supply, avoiding the regulation difficulties of traditional systems when cold and heat loads fluctuate. The high-temperature level heat pump subsystem receives the heat energy output by the low-temperature level heat pump subsystem, further increases the temperature and stores it in the first high-temperature heat storage tank 17. This process strengthens the grade improvement of heat energy, ensuring stable heat source supply when light-heat input is unstable.

[0104] The organic Rankine cycle power generation module is connected with the high-temperature level heat pump subsystem through the first high-temperature heat storage tank 17, and simultaneously utilizes the heat energy in the second high-temperature heat storage tank 19 for power generation. This module converts the stored high-temperature heat energy into electrical energy output, realizing the coordination of combined cooling, heating and power, and can prioritize power generation during peak load periods to balance grid demand, thereby improving the adaptability of multi-energy output and avoiding the imbalance between supply and demand under a single energy form.

[0105] The light-heat heat collection module is connected with the high-temperature level heat pump subsystem and the organic Rankine cycle power generation module through the medium-temperature heat storage tank 13 and the second high-temperature heat storage tank 19, respectively, for collecting solar energy and storing heat energy in the medium-temperature heat storage tank 13 and the second high-temperature heat storage tank 19. This connection mode enhances the coupling strength of light-heat and Carnot cell. The light-heat module directly supplements the heat source in sunny weather, reducing the dependence on grid power, and buffers the heat energy supply through the heat storage tank during rainy or night time, ensuring the flexible regulation of system load, while improving the stability and economy of multi-energy supply.

[0106] The provided light-heat coupled Carnot cell combined cooling, heating and power system realizes step-by-step utilization and multi-energy complementation of light-heat resources through modular integration, significantly improves energy conversion efficiency, reduces dependence on power grid, enhances load regulation flexibility, ensures stable output under light-heat fluctuation, improves multi-energy combined supply adaptability, cooperatively provides cooling, heating and power to adapt to diverse demands, reduces energy waste, promotes sustainable development, prolongs operation cycle and supports application of renewable energy in distributed scenarios.

[0107] As a preferred embodiment, the low-temperature stage heat pump subsystem is used to realize cold recovery and primary temperature rise of the circulating working medium after building cooling. It comprises a low-temperature cold storage tank 1, a first working medium pump 2, a first low-temperature evaporator 3, a first compressor 6, a first low-temperature stage condenser 7, an evaporative condenser 8 and a low-temperature regenerator 5.

[0108] The low-temperature cold storage tank 1 is used to collect the cold storage working medium released at the building terminal and provide stable cold source supply for the subsequent heat exchange process. The first working medium pump 2 is arranged at the outlet of the low-temperature cold storage tank 1 and forcibly transports the cold storage working medium, so that the first low-temperature evaporator 3 can complete heat exchange between the cold storage working medium and the circulating working medium under relatively stable flow conditions, thereby reducing the sensible heat load of the circulating working medium and improving the energy efficiency of the subsequent compression process.

[0109] The hot side outlet of the first low-temperature evaporator 3 is connected back to the inlet of the low-temperature cold storage tank 1, forming a closed cold storage loop. The cold side outlet of the evaporator I is further connected to the cold side inlet of the low-temperature regenerator 5. Through heat exchange between the low-temperature circulating working medium and the medium-temperature circulating working medium, the primary temperature of the circulating working medium can be raised before the suction of the first compressor 6, so that the pressure ratio of the first compressor 6 during operation is reduced, thereby helping to reduce energy consumption and improve operation stability.

[0110] The first compressor 6 is used to compress the low-temperature and low-pressure circulating working medium from the cold side outlet of the low-temperature regenerator 5 to a medium-temperature and medium-pressure state. The medium-temperature circulating working medium at the outlet of the first compressor 6 can enter the first low-temperature stage condenser 7 or the evaporative condenser 8 according to the operation requirements. Through switching adjustment of the three-way valve, the medium-temperature circulating working medium is distributed between different heat exchangers, which can meet the cold and heat demands of the system under different working conditions and improve the operation flexibility of the system.

[0111] The first low-temperature stage condenser 7 is mainly used to discharge the heat of the medium-temperature circulating working medium to the external medium, so that it is further condensed and cooled to provide a stable working medium state for the subsequent heat recovery process. The evaporative condenser 8 realizes heat energy transfer between the low-pressure stage and the high-pressure stage heat pump subsystem. Through heat exchange in this component, the medium-temperature circulating working medium plays the role of intermediate heat source in cross-stage energy coupling, which is conducive to improving the overall energy step utilization efficiency.

[0112] The hot side inlets of the low-temperature recuperator 5 are connected with the outlet of the first low-temperature stage condenser 7 and the hot side outlet of the evaporation condenser 8 respectively. Through the heat release of the medium-temperature cycle working medium at this point to the low-temperature cycle working medium, not only the temperature of the low-temperature cycle working medium before entering the first compressor 6 is improved, but also the medium-temperature cycle working medium obtains a more reasonable temperature distribution before flowing back to the evaporator or the next heat exchange unit, thereby improving the overall heat balance characteristics of the system.

[0113] With such an arrangement, the low-temperature stage heat pump subsystem can realize dynamic switching between cold storage recovery, cycle working medium preheating and cold and heat combined supply without increasing additional energy consumption, and the system energy efficiency and operation stability are both improved to a certain extent.

[0114] As a preferred embodiment, the low-temperature stage heat pump subsystem further comprises a second low-temperature evaporator 4, a first throttling valve 301 and a second throttling valve 302 to enhance the adaptability of the low-temperature side to different working conditions. The inlets of the two throttling valves are in communication with the hot side outlet of the low-temperature recuperator 5, and after throttling, the medium-temperature cycle working medium can be cooled and decompressed to a low-temperature and low-pressure state suitable for heat absorption of the low-temperature evaporator. The outlet of the first throttling valve 301 is connected to the cold side inlet of the first low-temperature evaporator 3, and the outlet of the second throttling valve 302 is connected to the inlet of the second low-temperature evaporator 4, so that the two evaporation paths can work respectively according to the operation requirements. The outlet of the second low-temperature evaporator 4 is connected with the cold side inlet of the low-temperature recuperator 5, and the temperature of the working medium is raised by absorbing environmental heat to provide a stable low-grade heat source for the subsequent compression process. Through the above structural arrangement, the low-temperature stage heat pump subsystem can flexibly select the evaporation path according to the ambient temperature and load change, improve the continuity of low-temperature heat source utilization and the stability of working medium heat exchange, and thus maintain the relative stability of the overall performance of the system under different working conditions.

[0115] As a preferred embodiment, the low-temperature stage heat pump subsystem is provided with a second low-temperature stage condenser 9, the inlet of which is connected with the outlet of the first low-temperature stage condenser 7 and the hot side outlet of the evaporation condenser 8. The outlet of the second low-temperature stage condenser 9 is in communication with the hot side inlet of the low-temperature recuperator 5, so that the working medium after condensation and heat release has a relatively stable temperature condition before entering the low-temperature recuperator 5. With such an arrangement, the system can flexibly switch the condensation heat source path under different external temperature or load conditions, so that the low-temperature stage heat release process is more stable, which helps to improve the heat matching of the subsequent recuperation process and makes the overall operation of the system more stable and reliable.

[0116] As a preferred embodiment, the low-temperature heat pump subsystem is further provided with a first three-way valve 401, a second three-way valve 402 and a third three-way valve 403 to realize switching between different heat exchange paths and improve the adaptability of low-temperature operation. The first three-way valve 401 is arranged at the outlet of the first compressor 6, and its two branches are connected to the inlet of the first low-temperature condenser 7 and the hot side inlet of the evaporative condenser 8 respectively, so that the compressor exhaust can be selected to directly enter the first low-temperature condenser 7 or exchange heat with the high-temperature evaporative condenser 8 according to the working condition. The second three-way valve 402 is installed at the outlet of the first low-temperature condenser 7 and connected to the hot side inlet of the low-temperature regenerator 5 and the inlet of the second low-temperature condenser 9 respectively, so that it can be branched between preferentially supplying the regenerator or entering another condenser. The third three-way valve 403 is arranged at the hot side outlet of the evaporative condenser 8, and its branch is connected to the inlet of the second low-temperature condenser 9 and the second three-way valve 402 respectively, so that the condensing working medium of the evaporative condenser 8 can be flexibly entered into different condensing paths. Through the combined arrangement of the above three-way valves, the low-temperature heat pump subsystem can smoothly switch between different operating modes, making the heat exchange path of the compressor exhaust more reasonable, thereby maintaining a relatively stable heat exchange efficiency and improving the adaptability of the overall system operation when the load changes or the source side conditions fluctuate.

[0117] As a preferred embodiment, the system selects energy storage media matched with the energy storage demand of different temperature zones. The low-temperature cold storage tank 1 uses glycol water solution as the cold storage medium, which has good fluidity and high specific heat capacity at low temperature, can ensure stable circulation while reducing the risk of icing and blocking during low-temperature operation. The medium-temperature heat storage tank 13 and the first high-temperature heat storage tank 17 use pressurized water as the heat storage medium, which can realize a wider temperature operating range by increasing the boiling point of water, making the heat storage process more stable and conducive to the continuous adjustment of medium-temperature and high-temperature heat sources. The second high-temperature heat storage tank 19 uses a solid-liquid phase change material as the heat storage medium, which has high latent heat storage capacity during the solid-liquid transition process and can provide a relatively stable heat release process at high temperature. Through the above hierarchical configuration of energy storage media, the system can make more full use of various types of heat energy according to the functional requirements of different temperature zones, improve the temperature matching degree and operating stability of the energy storage process, and thus improve the adjustment capability of the overall system. Preferably, the heat storage temperature of the first high-temperature heat storage tank 17 is 140-150°C, and the heat storage temperature of the second high-temperature heat storage tank 19 is 190-200°C.

[0118] As a preferred embodiment, the high-temperature stage heat pump subsystem comprises the evaporative condenser 8, the high-temperature regenerator 11, the second compressor 14, the high-temperature condenser 15, the high-temperature evaporator 10, and the corresponding heat storage devices to realize the cascade utilization of the medium-temperature and high-temperature heat sources. The cold side outlet of the evaporative condenser 8 is connected to the cold side inlet of the high-temperature regenerator 11 to transfer the heat provided by the low-temperature stage heat pump subsystem to the high-temperature stage, thereby improving the thermal energy connection efficiency between the two stages. The cold side outlet of the high-temperature regenerator 11 is connected to the inlet of the second compressor 14, so that the preheated medium-temperature circulating working medium enters the compression process in a relatively stable state. The outlet of the second compressor 14 is connected to the hot side inlet of the high-temperature condenser 15 to improve the temperature and pressure of the circulating working medium through compression, so that the circulating working medium has the ability to effectively exchange heat with the high-grade heat storage side. The hot side outlet of the high-temperature condenser 15 is connected to the hot side inlet of the high-temperature regenerator 11, and the high-temperature circulating working medium is cooled after heat exchange with the heat storage working medium, thereby providing a suitable heat source for the subsequent heat recovery process. The cold side inlet of the high-temperature evaporator 10 is connected to the hot side outlet of the high-temperature regenerator 11, and its cold side outlet returns to the cold side inlet of the high-temperature regenerator 11 to utilize the medium-temperature heat source to absorb heat from the circulating working medium. The inlet of the medium-temperature heat storage tank 13 is connected to the hot side outlet of the high-temperature evaporator 10, and the outlet is connected to the hot side inlet of the high-temperature evaporator 10 through the second working medium pump 12 to realize the storage and regulation of the medium-grade thermal energy. The inlet of the first high-temperature heat storage tank 17 is connected to the cold side outlet of the high-temperature condenser 15, and the outlet is connected to the cold side inlet of the high-temperature condenser 15 through the third working medium pump 16 to store the heat released during the high-temperature condensation process. Through the above structure, the high-temperature stage heat pump subsystem can smoothly realize heat transfer in different temperature ranges, maintain the continuity of the temperature change of the circulating working medium, thereby improving the utilization efficiency of the system for the staged heat sources and improving the stability of the overall operation.

[0119] As a preferred embodiment, the high-temperature stage heat pump subsystem is additionally provided with a third throttling valve 303 and a fourth throttling valve 304 to realize the pressure and temperature regulation of the high-temperature circulating working medium in different operating modes. Specifically, the third throttling valve 303 is arranged between the hot side outlet of the high-temperature regenerator 11 and the cold side inlet of the evaporative condenser 8 to complete the temperature and pressure reduction of the circulating working medium before it enters the evaporative condenser 8, so that it is more suitable for the cross-stage heat exchange conditions. The fourth throttling valve 304 is arranged between the hot side outlet of the high-temperature regenerator 11 and the cold side inlet of the high-temperature evaporator 10 to throttle the circulating working medium to a medium-temperature and low-pressure state to adapt to the evaporation working condition of the high-temperature evaporator 10.

[0120] With such a configuration, the high-temperature level heat pump subsystem can have two operating modes according to the heat source conditions and system load. When the third throttling valve 303 is open, the system operates in cascade mode, and the circulating working medium flows into the evaporative condenser 8 after throttling, absorbs heat from the low-temperature level heat pump subsystem, realizes the coupling of heat energy between the two levels of heat pumps, and is conducive to improving the overall heat pump efficiency when the low-temperature heat source is sufficient. When the fourth throttling valve 304 is open, the system switches to independent mode operation, and the circulating working medium enters the high-temperature evaporator 10 after throttling, absorbs heat from the medium-temperature heat storage tank 13, so that the high-temperature level heat pump can independently complete the high-grade heat energy output when the low-temperature level does not participate in operation, and improve the adaptability of the system in single-stage operation state.

[0121] By introducing two controlled shunt paths at the hot side outlet of the high-temperature regenerator 11, the working medium flow direction can be flexibly switched under different working conditions, so that the high-temperature level heat pump can smoothly switch between cascade operation and independent operation, thereby enhancing the adaptability of the system to changes in heat source and improving the overall heat management performance while keeping the structure simple.

[0122] As a preferred embodiment, the organic Rankine cycle power generation module adopts a structure configuration of staged heat storage and double-loop heat exchange. The first high-temperature heat storage tank 17 is in communication with the high-temperature level heat pump subsystem and is used to store the high-grade heat energy output by the high-temperature level heat pump subsystem. The outlet of the first high-temperature heat storage tank 17 enters the heat exchanger through the hot side of the oil-water heat exchanger 18, so that the high-temperature heat storage working medium exchanges heat with the heat conducting oil, and the hot side outlet of the oil-water heat exchanger 18 returns to the inlet of the first high-temperature heat storage tank 17, forming a stable high-temperature working medium circulation, so that the heat storage temperature remains relatively constant. The cold side outlet of the oil-water heat exchanger 18 is connected to the inlet of the second high-temperature heat storage tank 19, so that the heat conducting oil carries the heat from the photothermal heat collection module and temporarily stores it in the second high-temperature heat storage tank 19, and can still supply heat at a relatively stable temperature when the load changes. The outlet of the second high-temperature heat storage tank 19 is connected to the hot side inlet of the ORC evaporator 20, and the heat conducting oil transfers heat to the organic working medium in the evaporator, realizing the vaporization of the working medium. The high-temperature and high-pressure organic working medium after vaporization enters the expander 22 to do work and generate electricity, and the expanded working medium from the outlet of the expander 22 enters the ORC condenser 23, completes the condensation process, is pressurized by the fifth working medium pump 24, and is re-supplied to the cold side inlet of the ORC evaporator 20, realizing a closed cycle. On the other hand, the heat conducting oil releases heat in the ORC evaporator 20 hot side, is pressurized by the fourth working medium pump 21, and is selected by the three-way valve to return to the cold side inlet of the oil-water heat exchanger 18 or the inlet of the second high-temperature heat storage tank 19, for adjusting the circulation path and flow of the heat conducting oil, so that the system maintains an appropriate heat exchange temperature and stable power generation efficiency under different heat source inputs. Through the above structural arrangement, the system realizes effective heat storage and staged heat supply under multiple heat source conditions, so that the ORC working medium obtains a relatively constant evaporation temperature, thereby ensuring the stable operation of the expander 22 and the overall power generation performance.

[0123] As a preferred embodiment, the organic Rankine cycle power generation module is provided with multi-stage three-way valves at the heat transfer oil and heat source switching link to adapt to the heat supply demand under different operating conditions. A fourth three-way valve 404 is arranged at the outlet of the fourth working medium pump 21, which is used to select the flow direction of the heat transfer oil to the second high-temperature heat storage tank 19 or the cold side inlet of the oil-water heat exchanger 18 after the heat transfer oil is discharged through the ORC evaporator 20 according to the heat source state at that time, so as to realize relatively stable switching of the heat transfer oil circuit when the light heat input fluctuates. A fifth three-way valve 405 is arranged at the outlet of the second high-temperature heat storage tank 19, and by adjusting the valve position, it can be selected whether the high-temperature heat transfer oil obtained by light heat storage enters the ORC evaporator 20 directly, so as to maintain a more suitable heat source temperature for the evaporator to obtain when the power generation load changes or the heat storage temperature fluctuates. A sixth three-way valve 406 is arranged at the cold side inlet of the oil-water heat exchanger 18, which is used to receive the heat transfer oil from the outlet of the fourth working medium pump 21 and switch with the heat exchange oil path from the light heat collection module, so that different heat source inputs can be connected in an orderly manner at the inlet of the oil-water heat exchanger 18. The configuration of the above-mentioned three-way valves enables the heat transfer oil to be flexibly switched between multiple heat storage units and heat exchange links, which helps to reduce the influence of temperature fluctuations on the hot side of the ORC evaporator 20 under multi-heat source conditions, so as to make the vaporization temperature of the ORC working medium more stable, and ensure the continuity and stability of the operation of the subsequent expander 22.

[0124] As a preferred embodiment, the organic Rankine cycle power generation module realizes the switching input of the two types of heat sources of light heat storage and heat pump storage by the setting of the fifth three-way valve 405. When the fifth three-way valve 405 is in the working position of connecting the second high-temperature heat storage tank 19 and the ORC evaporator 20, the high-grade heat transfer oil from the light heat collection module and stabilized by the second high-temperature heat storage tank 19 is directly delivered to the ORC evaporator 20, so that the system can preferentially utilize the light heat source when the illumination condition is good, reduce the dependence on other heat sources, and at the same time maintain the relatively stable temperature of the hot side of the evaporator. When the fifth three-way valve 405 is switched to another position, the ORC evaporator 20 is heated by the heat transferred by the working medium of the first high-temperature heat storage tank 17 through the oil-water heat exchanger 18, so as to maintain the normal vaporization of the organic working medium in the case of insufficient or discontinuous light heat input. Through the above-mentioned dual heat source input mode, the system can flexibly allocate the heat supply path according to the external heat source conditions, improve the operating continuity and adaptability under different climate and load environments, and enable the ORC evaporator 20 to still obtain relatively stable heat input when the heat source fluctuates.

[0125] As a preferred embodiment, the photothermal heat collection module adopts a hierarchical heat storage and adjustable flow path structure to adapt to changes in light conditions. The solar heat collector 26 is used to heat the circulating heat transfer oil, and its outlet is connected to the second high-temperature heat storage tank 19 through the sixth working medium pump 25, so that the heat transfer oil can continuously circulate between heat collection and storage. When the light condition is good, the temperature of the heat transfer oil at the outlet of the heat collector is relatively high, and the seventh three-way valve 407 and the eighth three-way valve 408 can be adjusted to make the heat transfer oil directly flow into the second high-temperature heat storage tank 19 for storing high-grade heat energy, so as to realize high-efficiency heat energy capture on sunny days. When the light is insufficient but still provides some heat, the heat transfer oil at the outlet of the heat collector is guided to the electric heater 27 through the seventh three-way valve 407 for heating, so that its temperature is raised before entering the second high-temperature heat storage tank 19 to make up for the temperature fluctuations caused by unstable photothermal. For the working condition that requires to obtain medium-grade heat energy, the heat transfer oil at the outlet of the heat collector can enter the medium-temperature heat storage tank 13 according to the adjustment of the eighth three-way valve 408, so that the system can flexibly distribute heat energy in different temperature zones under partial load conditions. Through the above structural configuration, the photothermal heat collection module can switch between three operating modes, so that the heat transfer oil can realize direct heat storage, heat-supplementing heat storage or hierarchical heat storage according to the light condition, thereby improving the continuity and adaptability of photothermal utilization and reducing the influence of photothermal fluctuations on subsequent heat storage and evaporation units.

[0126] As a preferred embodiment, different types of circulating working medium are selected for each subsystem according to its operating temperature zone and heat exchange demand, so as to ensure that the system realizes relatively stable energy conversion under multi-stage temperature difference conditions. The low-temperature stage heat pump subsystem adopts R1234ze(E) as the circulating working medium, which still has good phase change characteristics at a lower evaporation temperature, and is suitable for obtaining heat from a low-temperature heat source and increasing its temperature. The high-temperature stage heat pump subsystem and the organic Rankine cycle power generation module adopt R1233zd(E) as the circulating working medium, which has good thermal stability at high temperature, so that the evaporator and the expander 22 can stably operate in a relatively high temperature range. The photothermal heat collection module adopts heat transfer oil as the circulating medium to adapt to the high-temperature output of the solar heat collector 26 and maintain relatively stable thermal properties in multiple cycles. In addition, the heat transfer oil is also used as the heat transfer medium between the oil-water heat exchanger 18 and the ORC evaporator 20, which utilizes its high thermal stability and wide working temperature range to make the heat exchange process between different temperature zones more stable. Through the above working medium configuration, each module operates in its suitable temperature range, which improves the overall heat exchange efficiency and reduces the performance loss when switching between different temperature zones.

[0127] Embodiment 2

[0128] The application also provides a method for operating the coupled photothermal Carnot cell combined heat and power system as described in Embodiment 1, and the steps thereof include:

[0129] The energy storage stage and the energy release stage are two processes, and are self-adaptively adjusted according to the external energy conditions and the cold and heat load changes.

[0130] In the energy storage stage, the system simultaneously runs the cascade heat pump cycle and the photo-thermal heat collection cycle. The first compressor 6 and the second compressor 14 are driven to run by the surplus power at the low valley of the power grid in the cascade heat pump cycle, the low-grade heat obtained from the environment or the return water side by the low-temperature heat pump subsystem is lifted through the evaporative condenser 8 and delivered to the high-temperature heat pump subsystem for further temperature rise, and the obtained high-temperature heat is stored in the first high-temperature heat storage tank 17 for energy output in the subsequent high-temperature working condition. Specifically, the cascade heat pump cycle and the photo-thermal heat collection cycle are run. The first compressor 6 and the second compressor 14 are driven to run by the surplus power at the low valley of the power grid in the cascade heat pump cycle, the first compressor 6 compresses the working medium R1234ze(E) at the cold side outlet of the low-temperature regenerator 5 to a high-temperature and high-pressure state, the high-temperature and high-pressure working medium R1234ze(E) transmits heat to the working medium R1233zd(E) through the evaporative condenser 8, and the second compressor 14 compresses the working medium R1233zd(E) at the cold side outlet of the high-temperature regenerator 11 to a high-temperature and high-pressure state. The working medium R1233zd(E) in the high-temperature and high-pressure state transmits heat to the pressurized water in the high-temperature condenser, the heat-absorbed pressurized water is stored in the first high-temperature heat storage tank 17, and the heat-released working media R1234ze(E) and R1233zd(E) continue to release heat in the low-temperature regenerator 5 and the high-temperature regenerator 11 respectively, and then enter the first low-temperature evaporator and the evaporative condenser 8 after being throttled and depressurized by the first throttling valve 301 and the third throttling valve 303 respectively, and then are heated in the low-temperature regenerator 5 and the second high-temperature regenerator 11 respectively, to complete the cascade heat pump cycle.

[0131] In the photo-thermal heat collection cycle, the solar heat collector 26 converts solar radiation into heat and heats the circulating heat transfer oil; according to the different output temperatures, the heat can be stored in the medium-temperature heat storage tank 13 or the second high-temperature heat storage tank 19, so as to provide a heat source of a corresponding temperature zone when the illumination is uneven or the load fluctuates. Specifically, the photo-thermal heat collection cycle uses the solar heat collector 26 to heat the heat transfer oil working medium, the heat transfer oil working medium after temperature rise enters the second high-temperature heat storage tank 19 to transmit heat to the solid-liquid phase change material therein, is pressurized by the sixth working medium pump 25 and enters the solar heat collector 26, to complete the photo-thermal heat collection cycle. Therefore, the energy storage process is to convert the surplus power of the power grid into high-grade heat energy through the cascade heat pump cycle and store the high-grade heat energy into the first high-temperature heat storage tank 17, and to convert the solar energy into high-grade heat energy through the photo-thermal heat collection cycle and store the high-grade heat energy into the second high-temperature heat storage tank 19.

[0132] In the energy release stage, the ORC cycle is operated, and the heat transfer oil successively passes through the oil-water heat exchanger 18 and the second high-temperature heat storage tank 19 to absorb the heat stored in the energy storage process, and the heat transfer oil with a higher temperature enters the ORC evaporator 20 to transfer heat to the R1233zd(E) working medium pressurized by the fifth working medium pump 24, and the high-temperature and high-pressure R1233zd(E) working medium enters the expander 22 to generate power, and then enters the ORC condenser 23 to be cooled, and then is pressurized by the fifth working medium pump 24 and enters the ORC evaporator 20 to complete the cycle. Through the heat grading storage in different temperature zones in the early stage, the power generation process can maintain relatively stable heat input when the external heat source changes. The energy release process can convert the stored high-grade heat energy into electricity according to the demand of the power grid.

[0133] In the case of partial load operation, the low-temperature level heat pump subsystem and the high-temperature level heat pump subsystem can be independently operated to improve the adjustment capability of the system. When the low-temperature level heat pump subsystem is independently operated, the first low-temperature evaporator 3 can be selected to provide cold energy according to the needs, or the second low-temperature evaporator 4 can be activated to take heat from the environment, and the first low-temperature level condenser 7 or the second low-temperature level condenser 9 can be activated as a heat supply end according to the load demand to realize flexible output of cold and heat. When the high-temperature level heat pump subsystem is independently operated, the medium-temperature heat storage tank 13 is used as its heat source, and the system still has high-temperature energy storage capability in the absence of light or weak light conditions through the storage of the heat after temperature rising in the first high-temperature heat storage tank 17.

[0134] In addition, in order to adapt to the daily change rule of light conditions, when the light is sufficient, the system preferentially stores the high-temperature heat transfer oil generated by the collector in the second high-temperature heat storage tank 19 to improve the proportion of solar energy utilization; when the light is insufficient, the electric heater 27 is involved to supplement the heat of the heat transfer oil, so that the heat storage process is not interrupted due to light fluctuations. Through the above operation strategy, the system can maintain stable energy storage and energy supply capability under different external conditions, and realize the coordinated output of cold, heat and electricity.

[0135] As a preferred embodiment, the heat energy stored in the medium-temperature heat storage tank 13, the first high-temperature heat storage tank 17 and the second high-temperature heat storage tank 19 can be distributed and output according to the type and temperature level of the external heat load. When the external demand is medium-temperature heat supply, the heat can be directly released from the medium-temperature heat storage tank 13 to realize relatively stable medium-temperature heat source supply; when higher temperature heat is needed, the heat can be taken from the first high-temperature heat storage tank 17 or the second high-temperature heat storage tank 19 to meet the heat supply requirements of process heating or building high-temperature heating and other scenes. Through the grading scheduling of different temperature zone heat storage units, the system can provide matched heat energy output in various working conditions, improve the flexibility of heat storage utilization, and reduce energy waste caused by heat demand fluctuations.

[0136] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structural changes made according to the content of the present application specification and drawings, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A Carnot battery combined cooling, heating and power system coupled with photothermal energy, characterized in that, include: The cascade heat pump module includes a low-temperature stage heat pump subsystem and a high-temperature stage heat pump subsystem coupled together via an evaporator and condenser. The low-temperature heat pump subsystem is used to utilize grid power to upgrade low-grade heat energy into high-grade heat energy and provide cooling for buildings. The high-temperature stage heat pump subsystem is used to further heat up the heat energy provided by the low-temperature stage heat pump subsystem and store the high-grade heat energy in the first high-temperature heat storage tank; The organic Rankine cycle power generation module is connected to the high-temperature heat pump subsystem through a first high-temperature heat storage tank, and is used to generate electricity by utilizing the heat energy stored in the first and second high-temperature heat storage tanks. The solar thermal collector module is connected to the high-temperature heat pump subsystem and the organic Rankine cycle power generation module through a medium-temperature thermal storage tank and a second high-temperature thermal storage tank, respectively, to collect solar energy and store thermal energy in the medium-temperature thermal storage tank and the second high-temperature thermal storage tank.

2. The Carnot battery combined cooling, heating and power system coupled with photothermal energy according to claim 1, characterized in that, The cryogenic heat pump subsystem includes: Low-temperature cold storage tanks are used to store the cold storage medium after it has been used to cool buildings; The first working fluid pump is connected to the outlet of the cryogenic storage tank and is used to transport the cryogenic working fluid. The first low-temperature evaporator has its hot-side inlet connected to the outlet of the first working fluid pump and its hot-side outlet connected to the inlet of the low-temperature cold storage tank, and is used for heat exchange between the cold storage working fluid and the circulating working fluid. The first compressor is connected to the cold side outlet of the low-temperature regenerator at its inlet, and is used to compress the low-temperature, low-pressure circulating working fluid into a medium-temperature, medium-pressure state. The first low-temperature stage condenser has its inlet connected to the outlet of the first compressor and is used for heat exchange between the medium-temperature circulating working fluid and the external medium. An evaporative condenser, whose hot-side inlet is connected to the outlet of the first compressor, is used for heat exchange between the low-pressure stage heat pump working fluid and the high-pressure stage heat pump working fluid. The low-temperature regenerator has its cold-side inlet connected to the cold-side outlet of the first low-temperature evaporator for heat exchange between the low-temperature circulating working fluid and the medium-temperature circulating working fluid; its hot-side inlet is connected to the outlet of the first low-temperature stage condenser and the hot-side outlet of the evaporator-condenser respectively through a three-way valve.

3. A Carnot battery combined cooling, heating and power system with coupled photothermal energy according to claim 2, characterized in that, The low-temperature heat pump subsystem also includes a second low-temperature evaporator, a first throttling valve, and a second throttling valve; The inlets of both throttling valves are connected to the hot-side outlet of the low-temperature regenerator, which is used to cool and depressurize the medium-temperature circulating working fluid to a low-temperature and low-pressure state; the outlet of the first throttling valve is connected to the cold-side inlet of the first low-temperature evaporator, and the outlet of the second throttling valve is connected to the inlet of the second low-temperature evaporator. The outlet of the second low-temperature evaporator is connected to the cold-side inlet of the low-temperature regenerator for extracting heat from the environment.

4. A Carnot battery combined cooling, heating, and power system with coupled photothermal energy according to claim 2 or 3, characterized in that, The low-temperature stage heat pump subsystem also includes a second low-temperature stage condenser, whose inlet is connected to the outlet of the first low-temperature stage condenser and the hot-side outlet of the evaporator-condenser via a three-way valve, and whose outlet is connected to the hot-side inlet of the low-temperature regenerator.

5. A Carnot battery combined cooling, heating and power system with coupled photothermal energy according to any one of claims 1-3, characterized in that, The high-temperature heat pump subsystem includes: The evaporator-condenser has its cold-side outlet connected to the cold-side inlet of the high-temperature regenerator, which is used to realize the heat energy transfer between the low-pressure stage and the high-pressure stage heat pump subsystem. The high-temperature regenerator has its cold-side outlet connected to the inlet of the second compressor and is used for heat exchange between the medium-temperature and high-temperature circulating working fluids. The second compressor has its outlet connected to the hot side inlet of the high-temperature condenser, and is used to compress the medium-temperature low-pressure circulating working fluid into a high-temperature and high-pressure state. A high-temperature condenser, whose hot-side outlet is connected to the hot-side inlet of a high-temperature regenerator, is used for heat exchange between the high-temperature circulating working fluid and the heat storage working fluid. A high-temperature evaporator, with its cold-side inlet connected to the hot-side outlet of a high-temperature regenerator and its cold-side outlet connected to the cold-side inlet of a high-temperature regenerator, is used for heat exchange between a medium-temperature heat source and a circulating working fluid. The medium-temperature thermal storage tank has its inlet connected to the hot-side outlet of the high-temperature evaporator, and its outlet connected to the hot-side inlet of the high-temperature evaporator via a second working fluid pump, for storing medium-grade thermal energy. The first high-temperature thermal storage tank has its inlet connected to the cold-side outlet of the high-temperature condenser, and its outlet connected to the cold-side inlet of the high-temperature condenser via a third working fluid pump. It is used to store high-grade thermal energy.

6. A Carnot battery combined cooling, heating and power system coupled with photothermal energy according to claim 5, characterized in that, The high-temperature heat pump subsystem also includes a third throttle valve and a fourth throttle valve; The third throttle valve is connected between the hot side outlet of the high-temperature regenerator and the cold side inlet of the evaporator-condenser, and the fourth throttle valve is connected between the hot side outlet of the high-temperature regenerator and the cold side inlet of the high-temperature evaporator. It is used to cool and depressurize the high-temperature circulating working fluid to a medium-temperature and low-pressure state. When the third throttle valve is opened, the system operates in cascade mode and receives heat energy from the low-pressure stage heat pump subsystem through the evaporator-condenser. When the fourth throttle valve is opened, the system operates in independent mode, obtaining heat energy from the medium-temperature heat storage tank through the high-temperature evaporator.

7. A Carnot battery combined cooling, heating and power system with coupled photothermal energy according to any one of claims 1-3, characterized in that, The organic Rankine cycle power generation module includes: The first high-temperature thermal storage tank is used to store high-grade thermal energy from the high-temperature heat pump subsystem. An oil-water heat exchanger, with its hot-side inlet connected to the outlet of the first high-temperature heat storage tank and its hot-side outlet connected to the inlet of the first high-temperature heat storage tank, is used for heat exchange between the high-temperature heat storage medium and the heat transfer oil. The second high-temperature thermal storage tank is connected to the cold side outlet of the oil-water heat exchanger and is used to store high-grade thermal energy from the solar thermal collector module. The ORC evaporator has its hot-side inlet connected to the outlet of the second high-temperature heat storage tank for heat exchange between the heat transfer oil and the organic working fluid. The expander, with its inlet connected to the cold-side outlet of the ORC evaporator, is used for expanding the high-temperature, high-pressure organic working fluid to generate electricity. The ORC condenser has its inlet connected to the outlet of the expander and is used for condensing the expanded organic working fluid. The fifth working fluid pump is connected between the outlet of the ORC condenser and the cold-side inlet of the ORC evaporator for pressurizing and circulating the organic working fluid. The fourth working fluid pump has its inlet connected to the hot side outlet of the ORC evaporator, and its outlet connected to the cold side inlet of the oil-water heat exchanger and the inlet of the second high-temperature heat storage tank via a three-way valve, for the circulation of heat transfer oil.

8. A Carnot battery combined cooling, heating and power system with coupled photothermal energy according to any one of claims 1-3, characterized in that, The photothermal heat collection module includes: Solar collectors are used to collect solar energy and heat circulating working fluid; The sixth working fluid pump is connected between the outlet of the second high-temperature thermal storage tank and the inlet of the solar collector to drive the circulation of heat transfer oil; An electric heater, with its inlet connected to the outlet of the solar collector, is used to supplement the heat transfer oil when sunlight is insufficient. A medium-temperature thermal storage tank, with its inlet connected to the outlet of the solar collector, is used to store medium-grade thermal energy; The second high-temperature thermal storage tank has its inlet connected to the outlet of the electric heater, the outlet of the medium-temperature thermal storage tank, and the outlet of the solar collector, respectively, and is used to store high-grade thermal energy.

9. A method for operating a Carnot battery combined cooling, heating and power system coupled with photothermal energy as described in any one of claims 1-8, characterized in that, Its steps include: an energy storage phase and an energy release phase; The energy storage phase includes the operation of a cascade heat pump cycle and a solar thermal collector cycle; In the cascade heat pump cycle, the surplus power from the grid drives the first compressor and the second compressor. The low-temperature heat pump subsystem enhances the low-grade heat energy and supplies heat to the high-temperature heat pump subsystem through the evaporator-condenser. The high-grade heat energy generated by the high-temperature heat pump subsystem is stored in the first high-temperature heat storage tank. In the solar thermal collection cycle, the solar collector collects solar-heated heat transfer oil and stores the heat in the medium-temperature heat storage tank and / or the second high-temperature heat storage tank; The energy release phase operates an organic Rankine cycle for power generation; the thermal energy stored in the first and second high-temperature thermal storage tanks is used to heat the working fluid of the organic Rankine cycle power generation module, driving the expander to generate electricity.

10. The operating method according to claim 9, characterized in that, The low-temperature heat pump subsystem and the high-temperature heat pump subsystem can operate independently according to load demand: When the low-temperature heat pump subsystem is running independently, the first low-temperature evaporator can be selectively activated for cooling or the second low-temperature evaporator can be activated to extract heat from the environment, and the first low-temperature condenser and the second low-temperature condenser can be selectively activated for heating. When the high-temperature heat pump subsystem operates independently, it uses the medium-temperature heat storage tank as a heat source and stores the generated high-grade heat energy in the first high-temperature heat storage tank.

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