Optimization method, device, equipment and medium of combined cooling heating and power system

Abstract

The invention relates to the technical field of energy, in particular to an optimization method, device, equipment and medium for a combined cooling heating and power system, and the method comprises the steps: determining an optimization target value of the combined cooling heating and power system, obtaining a decision variable of the combined cooling heating and power system, and according to a preset optimization strategy and in combination with a constraint condition, optimizing the optimization target value of the combined cooling heating and power system; and performing iterative optimization processing on the decision variables until a preset convergence condition is met, and obtaining an optimization result corresponding to each decision variable. Thus, the decision variable can be optimized by setting the optimization target value and based on the preset optimization strategy, the energy conversion and transmission process among the energy storage and release unit, the circulation unit and the refrigeration unit is effectively coordinated, the residual heat energy generated by the energy storage and release unit is fully recycled, efficient recycling of waste heat is achieved, and the energy utilization rate of the refrigeration unit is improved. Therefore, the energy utilization efficiency of the whole system is greatly improved, and energy waste is reduced.

Description

Technical Field

[0001] The present application relates to the field of energy technology, and in particular to an optimization method, device, equipment, and medium for a combined cooling, heating, and power system. Background Art

[0002] With the rapid development of renewable energy, the intermittency and uncontrollability of renewable energy have become urgent problems to be solved. Combined Cooling Heating and Power (CCHP), as a comprehensive energy utilization method of multi-energy cogeneration, can provide electricity, heat and cold energy at the same time and has received widespread attention.

[0003] However, the CCHP system in the related art usually has the problem of insufficient utilization of compression heat energy and flue gas waste heat, resulting in a significant reduction in energy conversion and transmission efficiency.

[0004] Therefore, a system optimization method is urgently needed to improve the overall energy conversion efficiency of CCHP systems. Summary of the invention

[0005] In view of the above problems, the present invention provides an optimization method, device, equipment and medium for a trigeneration system of cooling, heating and power, so as to improve the energy conversion efficiency of the trigeneration system of cooling, heating and power.

[0006] In a first aspect, the present application provides an optimization method for a cooling, heating and power trigeneration system, the method comprising:

[0007] Determine the optimization target value of the trigeneration system;

[0008] Based on the optimization target value, obtaining decision variables of the trigeneration system;

[0009] Based on the preset optimization strategy and in combination with the constraint conditions, the decision variables are iteratively optimized until the preset convergence conditions are met, and the optimization results corresponding to the decision variables are obtained;

[0010] Among them, the trigeneration system of cooling, heating and power converts excess electricity into air internal energy through the energy storage and release unit in the energy storage stage, and stores the air internal energy, and releases the air internal energy in the energy release stage to obtain electrical energy; obtains the residual heat energy of the energy storage and release unit through the circulation unit, and converts the residual heat energy into electrical energy; and converts the residual heat energy of the energy storage and release unit into cold energy through the refrigeration unit to obtain cooling capacity.

[0011] In a second aspect, the present application provides an optimization device for a trigeneration system, the device comprising:

[0012] A target determination unit, used to determine an optimization target value of the trigeneration system;

[0013] A variable acquisition unit, used for acquiring a decision variable of the trigeneration system based on the optimization target value;

[0014] The system optimization unit is used to iteratively optimize the decision variables based on a preset optimization strategy and in combination with constraint conditions until a preset convergence condition is met to obtain an optimization result corresponding to each decision variable;

[0015] Among them, the trigeneration system of cooling, heating and power converts excess electricity into air internal energy through the energy storage and release unit in the energy storage stage, and stores the air internal energy, and releases the air internal energy in the energy release stage to obtain electrical energy; obtains the residual heat energy of the energy storage and release unit through the circulation unit, and converts the residual heat energy into electrical energy; and converts the residual heat energy of the energy storage and release unit into cold energy through the refrigeration unit to obtain cooling capacity.

[0016] Optionally, the optimization target value includes a round-trip efficiency value and an investment cost value, and the round-trip efficiency value represents the ratio of the total energy output of the system to the total energy input.

[0017] Optionally, the decision variables include: the internal combustion engine inlet temperature of the combustion chamber, the evaporation temperature of the circulation unit, the condensation temperature of the circulation unit, the mass flow rate of the working fluid, the desorber temperature of the refrigeration unit, the absorber temperature and the mass flow rate of the refrigeration unit.

[0018] Optionally, the constraints include: a first constraint of the internal combustion engine inlet temperature, and second constraints of the evaporation temperature and the condensation temperature.

[0019] In a third aspect, the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the optimization method for the trigeneration system of any one of the above-mentioned first aspects is implemented.

[0020] In a fourth aspect, the present application provides a computer storage medium, wherein the computer-readable storage medium stores computer program instructions, and the computer program instructions are executed by a processor to perform any one of the methods for optimizing a trigeneration system in the first aspect.

[0021] In a fifth aspect, an embodiment of the present application provides a computer program product, comprising computer program instructions, which, when executed by a processor, implement any one of the optimization methods for the trigeneration system of the first aspect described above.

[0022] The beneficial effects of the present invention are as follows:

[0023] The embodiment of the present application provides an optimization method for a trigeneration system of cooling, heating and power. The optimization target value of the trigeneration system of cooling, heating and power is determined, the decision variables of the trigeneration system of cooling, heating and power are obtained, and the decision variables are iteratively optimized according to the preset optimization strategy and in combination with the constraint conditions until the preset convergence conditions are met, and the optimization results corresponding to each decision variable are obtained. In this way, the embodiment of the present application can effectively coordinate the energy conversion and transmission process between the energy storage and release unit, the circulation unit and the refrigeration unit by setting the optimization target value and optimizing the decision variables based on the preset optimization strategy, so that the residual heat energy generated by the energy storage and release unit can be fully recycled and utilized, and the efficient reuse of the residual heat can be achieved, thereby greatly improving the energy utilization efficiency of the entire system and reducing energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 A schematic flow chart of an optimization method for a cooling, heating and power trigeneration system provided in an embodiment of the present application;

[0026] Figure 2 A schematic diagram of the structure of a cooling, heating and power trigeneration system provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram showing the effect of different working fluids on system performance in a circulation unit provided in an embodiment of the present application;

[0028] Figure 4 A schematic diagram of the structure of an optimization device for a cooling, heating and power trigeneration system provided in an embodiment of the present application;

[0029] Figure 5 A schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other. In addition, although the logical order is shown in the flow chart, in some cases, the steps shown or described can be performed in an order different from that here.

[0031] The terms "first" and "second" in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the term "comprising" and any of their variations are intended to cover non-exclusive protection. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices. "Multiple" in the present application can mean at least two, for example, can be two, three or more, and the embodiments of the present application are not limited.

[0032] The term "and / or" in the embodiments of the present application is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0033] The following is a brief introduction to the design concept of the embodiments of the present application.

[0034] Renewable energy has been developing rapidly due to its advantages such as environmental friendliness, abundant resources, energy security and high economic benefits. According to the International Energy Agency (IEA) in 2019 world renewable electricity statistics, the share of renewable energy in global power generation reached almost 23.2% in 2019. However, due to its intermittent and difficult to control nature, renewable energy often leads to unstable power supply and difficulty in meeting energy storage needs, which has become an urgent problem that must be solved.

[0035] Combined Cooling Heating and Power (CCHP) is a comprehensive energy utilization method of multi-energy cogeneration that can provide electricity, heat and cold energy at the same time, and has received widespread attention. However, during the operation of the CCHP system in the related technology, it usually relies on compressed air energy storage technology (CAES) to convert electrical energy into air internal energy. However, in the compressed air energy storage and energy release stage, due to unreasonable system design and control strategy, the heat energy generated in the air compression stage cannot be fully recovered and utilized. In addition, in the energy release stage of the system, the waste heat of flue gas generated by the combustion of natural gas is not fully utilized, thereby reducing the overall energy utilization efficiency of the system. Therefore, there is an urgent need for a system optimization method to improve the overall energy conversion efficiency of the CCHP system.

[0036] In order to solve the above problems, the embodiment of the present application provides an optimization method for a CCHP system, which determines the optimization target value of the CCHP system, and then obtains the decision variables of the CCHP system according to the optimization target value, and performs iterative optimization processing on the decision variables by combining the preset optimization strategy with the constraint conditions until the preset convergence conditions are met, and obtains the optimization results corresponding to each decision variable. In this way, by setting the optimization target value and continuously optimizing the decision variables based on the preset optimization strategy, it is ensured that each unit of the system can operate under the best working condition, and the energy conversion and transmission process between the energy storage and release unit, the circulation unit and the refrigeration unit is effectively coordinated, so that the residual heat energy generated by the energy storage and release unit can be fully recycled and utilized, and the efficient reuse of the waste heat is realized, and energy waste is reduced, thereby improving the overall energy utilization rate of the CCHP system, and by reasonably setting the decision variables of the system, it is possible to reduce unnecessary fuel consumption and reduce the operating cost of the system.

[0037] The following briefly introduces the application scenarios to which the technical solutions of the embodiments of the present application can be applied. It should be noted that the application scenarios introduced below are only used to illustrate the embodiments of the present application and are not limited. In the specific implementation process, the technical solutions provided by the embodiments of the present application can be flexibly applied according to actual needs.

[0038] The solution provided by the embodiment of the present application can be applied to most application scenarios that require the supply of cold energy, electric energy, and heat energy, and is used to improve energy utilization. For example, in a large-scale industrial park, factories usually need to meet the needs of electricity, heat, and refrigeration at the same time. The optimization method of the trigeneration system of cold, heat, and power provided by the embodiment of the present application can optimize the CCHP system in industrial production, so that the excess electricity generated in industrial production can be used by the CCHP system to efficiently convert it into electric energy, heat energy, and cold energy, which can not only provide a stable energy supply for enterprises in the park, but also reduce energy waste and improve the overall energy efficiency of the park. For example, during peak power consumption, the CCHP system can be used as a peak shaving measure. During low power consumption periods, excess power can be used to compress air and store it in an energy storage and release unit to convert it into high-pressure air internal energy. During peak power consumption, the stored high-pressure air is released to generate electricity through a turbine, thereby using the stored energy, reducing the direct dependence on the power grid during peak periods, and thus reducing the pressure on the power grid during peak periods. At the same time, the waste heat released during system operation can also be converted into thermal energy or cold energy through a refrigeration unit or a circulation unit to provide heating or cooling support, further improving energy utilization efficiency.

[0039] Of course, the method provided in the embodiment of the present application is not limited to the above application scenarios, but can also be used in other possible application scenarios, which are not limited by the embodiment of the present application. The functions that can be realized by each device in the above application scenarios will be described in the subsequent method embodiments, and no further details will be given here.

[0040] Below, in combination with the application scenarios described above, the method provided by the exemplary embodiment of the present application is described with reference to the accompanying drawings. It should be noted that the above application scenarios are only shown to facilitate understanding of the spirit and principles of the present application, and the implementation methods of the present application are not limited in this regard.

[0041] like Figure 1 As shown, the embodiment of the present application provides an optimization method for a cooling, heating and power trigeneration system, and the specific process of the method is as follows:

[0042] Step 101: Determine the optimization target value of the CCHP system.

[0043] In the embodiments of the present application, the optimization target of the CCHP system can be selected according to the actual scenario and actual needs, such as improving the energy conversion performance of the system and / or reducing unnecessary energy consumption of the system, so as to achieve flexible optimization of the CCHP system.

[0044] In a possible implementation, maximizing the round trip efficiency (RTE) and minimizing the investment cost per unit output power (ICPP) can be selected as the optimization target values. RTE is one of the important indicators for evaluating the performance of energy storage systems. It represents the ratio of the total energy output of the system to the total energy input, reflecting the energy utilization efficiency of the system. ICPP represents the investment cost and output power of the system, and is used to evaluate the economic performance of the system.

[0045] Specifically, the function expression of RTE is as follows:

[0046]

[0047]

[0048] Among them, RTE CCHP Represents the round-trip efficiency of the CCHP system, that is, the energy conversion efficiency of the system, which represents the ratio between input energy and output energy. The optimization goal is to maximize the round-trip efficiency of the system.

[0049] and Represent the output power of turbines OT1 and OT2 respectively.

[0050] and They represent the output power of the high pressure turbine (HPT) and the low pressure turbine (LPT) respectively.

[0051] Represents the output power of the aftercooler (AC).

[0052] and and represent the output powers of pump OP1 and pump OP2 respectively.

[0053] Represents the total power consumption of the pumps in the system, which are used to circulate the fluid to keep the system running.

[0054] h, Represent mass flow, enthalpy and heat flow respectively. Represents the mass flow rate of air in the system, including the flow rate of air in the compression stage and the energy release stage. and Represent the flow rates of the working fluid in ORC1 and ORC2 respectively. out and h in They represent the enthalpy values ​​of the fluid when it enters and flows out of a unit respectively. The difference in enthalpy values ​​represents the heat absorbed or released by the fluid in the system. Represents the heat flow generated by the fuel, usually the energy provided by natural gas during combustion, Represents the cooling capacity generated by refrigeration.

[0055] t charging and t discharging Represent the duration of the energy storage phase and the energy release phase respectively.

[0056] Specifically, the function expression of ICPP is as follows:

[0057]

[0058]

[0059] Among them, ICPP represents the investment cost per unit output power of the CCHP system, which is the optimization target value of this time.

[0060] Represents the total cost rate of the CCHP system, including, for example, capital cost of equipment, fuel cost, and all other costs associated with the operation of the system.

[0061] Represents the investment cost rate of the CCHP system, including equipment depreciation, maintenance and other related expenses. The average annual cost of the entire system during its life cycle is calculated.

[0062] Represents the fuel cost rate of the CHP system, that is, the cost caused by fuel consumption.

[0063] and They represent the output power of the turbine and the input power of the aftercooler respectively.

[0064] Represents the output power of the ORC unit, i.e. the power generated by the cycle using waste heat to generate electricity.

[0065] Represents the total power consumption of all pumps in the system, which are used to circulate the fluid to keep the system running.

[0066] Capital Recovery Factor (CRF): Converts the initial capital investment of a system into an equivalent annual cost.

[0067] γ represents the maintenance factor, D represents the annual operating days, i r represents the discount rate or interest rate of the system, and N represents the useful life of the system.

[0068] Step 102: Based on the optimization target value, the decision variables of the trigeneration system are obtained.

[0069] In the embodiment of the present application, after selecting the optimization target value of CCHP, the system parameters that directly affect the performance and efficiency of the system can be selected as decision variables according to the actual optimization requirements and the performance of the CCHP system, so as to be used for subsequent parameter adjustment to achieve optimization of the system.

[0070] In a possible implementation, the internal combustion engine inlet temperature (Tcc,in) of the combustion chamber in the energy storage and release unit, the evaporation temperature (Toe1 and Toe2) of the circulation unit, the condensation temperature (Toc1, Toc2) of the circulation unit, the mass flow rate of the working fluid (mwf1, mwf2), the desorber temperature (Tdes) of the refrigeration unit, the absorber temperature (Tabs) and the mass flow rate (mars) of the refrigeration unit can be selected as decision variables. These decision variables directly affect the performance and efficiency of the system, and the system can be optimized by adjusting the values ​​of the decision variables.

[0071] Step 103: Based on the preset optimization strategy and in combination with the constraint conditions, the decision variables are iteratively optimized until the preset convergence conditions are met, and the optimization results corresponding to the decision variables are obtained.

[0072] In the embodiment of the present application, after the optimization target value and decision variables are determined, the decision variables will be adjusted according to the preset optimization strategy and the constraints on the decision variables, and the next optimization process will be performed through the adjusted decision variable values ​​until the preset convergence conditions are met, and the current decision variables are output, which is the optimization result of the CCHP system. In this way, by continuously optimizing the decision variables, it is ensured that each unit of the system can operate in the best working condition, further improving the overall energy utilization of the system, and reasonably setting the decision variables of the system can reduce unnecessary fuel consumption and reduce the operating cost of the system.

[0073] In a possible implementation, the internal combustion engine inlet temperature (Tcc,in) of the combustion chamber can be constrained as the first constraint to ensure combustion efficiency and equipment safety, and the evaporation temperature (Toe1 and Toe2) and condensation temperature (Toc1, Toc2) of the ORC unit can be constrained as the second constraint according to the properties of the working fluid and the requirements of the system.

[0074] In a possible implementation, the embodiment of the present application can use a multi-objective optimization algorithm to iteratively optimize the system, such as the non-dominated sorting genetic algorithm II (NSGA-II) algorithm. The embodiment of the present application can be simulated in a process simulation software such as Aspen Plus, and the simulation results are transmitted to a high-level programming language and an interactive environment such as Matlab to calculate the objective function and update the decision variables, and then the updated decision variables are transmitted back for the next round of simulation. This cycle is repeated until the maximum number of iterations is reached or the preset convergence condition is met.

[0075] Specifically, taking the NSGA-II algorithm as an example, the key parameters can be set as follows: the maximum number of iterations is 100, the population size is 100, the crossover percentage is 0.5, the mutation ratio is 0.02, and the mutation step is 10% of the difference between the upper and lower bounds. Through the above iterative optimization process, the optimal solution frontier is obtained, from which the optimal solution that meets the actual needs is selected.

[0076] To further explain the above optimization method for CCHP system, Figure 2 As shown, the embodiment of the present application also provides a schematic diagram of the system structure of a trigeneration system of cooling, heating and power, which includes an energy storage and release unit, a circulation unit and a refrigeration unit:

[0077] The energy storage and release unit, namely the Compressed Air Energy Storage (CAES), is used to convert excess electricity generated by renewable energy or the power grid into air internal energy and store the air internal energy during the energy storage stage. In the energy release stage, the air internal energy is released to obtain electrical energy.

[0078] Cycle unit, i.e. Figure 2 The organic Rankine cycle system (ORC) shown includes two cycle subunits, ORC1 and ORC2, which are used to obtain the residual heat energy of the energy storage and release unit and convert the residual heat energy into electrical energy.

[0079] Refrigeration unit, i.e. Figure 2 The absorption refrigeration system (ARS) shown is used to convert the residual heat energy of the energy storage and release unit and the circulation unit into cold energy to obtain cooling capacity.

[0080] In a possible implementation, the energy storage and release unit may be composed of an energy storage subunit and an energy release subunit. The energy storage subunit may compress air into high-pressure air through excess electricity and store the high-pressure air in an air storage cave (such as Figure 2The energy-releasing subunit can release the high-pressure air to obtain high-temperature flue gas, and generate electricity through the thermal energy of the high-temperature flue gas. The gas storage cave is an underground storage unit for storing high-pressure air. It can be a large cave such as a salt cave, a mine cave, a rock cave or a large underground gas storage. The embodiment of the present application does not specifically limit this. The compressed air will be stored in the gas storage cave until it is used in the energy release stage.

[0081] In one possible implementation, the energy storage subunit may include a multi-stage compressor, such as Figure 2 The low-pressure compressor (LPC) LPC, 6-stage high-pressure compressors (HPC) HPC1-HPC6 and coolers shown in the figure can further improve the thermal efficiency of the system. The compressor is used to compress the air through excess power to obtain high-pressure air. The cooler includes intercoolers (IC) and aftercoolers (AC), such as the above Figure 2 The IC1-IC6 and AC shown are mainly used to obtain the residual heat energy of the compressor and transmit the residual heat energy to the ORC unit.

[0082] Specifically, the compression medium of the compressor can be air, and the working medium of the intercooler and the aftercooler can also be used as the working medium of the ORC1 unit, and they are arranged in parallel, using a shell and tube heat exchanger.

[0083] In a possible implementation, the energy release subunit further includes a combustion chamber (CC), a first turbine and a recuperator (REC). Figure 2 The two-stage combustion chambers CC1 and CC2 shown are used to burn fuel and high-pressure air to obtain high-temperature flue gas. The first turbine may include a high-pressure turbine (HPT) and a low-pressure turbine (LPT) to convert the heat energy of the high-temperature flue gas into electrical energy. The low-pressure turbine can also be used to discharge exhaust gas and preheat the air. The regenerator is used to transfer the remaining heat energy of the high-temperature flue gas to the ORC system.

[0084] In one possible implementation, the outlet of the compressor is connected to the air storage cave, and the outlet of the air storage cave is connected to a regulating valve (REG), so that the energy storage subunit can adjust the pressure of the high-pressure air through the regulating valve and provide high-pressure air to the energy release subunit to drive the first turbine to generate electricity.

[0085] In a possible embodiment, during the energy storage stage, the outlet temperature of the multi-stage compressor is controlled by IC and AC. The functions of IC and AC are the same as those of the evaporator, evaporating the liquid working fluid by low-grade waste heat, the saturated vapor working fluid further expands through the turbine of the ORC unit to generate electricity, the low-pressure working fluid is liquefied in the condenser and pressurized by the pump device, and the cycle is repeated.

[0086] In one possible implementation, during the energy release and discharge stage, the outlet valve of the gas storage cavern will be opened to allow high-pressure air to enter the combustion chamber. After the high-temperature flue gas generated by combustion in the combustion chamber enters the turbine for power generation, the temperature is still relatively high. The waste heat of the flue gas will be divided into two parts, one part is used to drive the ORC system to generate electricity, and the other part is used to drive the ARS system to generate refrigeration energy.

[0087] In a possible embodiment, the combustion chamber includes a first combustion chamber CC1 and a second combustion chamber CC2, and the first combustion chamber, the high-pressure turbine, the second combustion chamber and the low-pressure turbine are connected in sequence in the order of CC1-HPT-CC2-LPT.

[0088] Specifically, natural gas can be used as the fuel of the energy release subunit. In the CAES unit, the excess electricity generated by renewable energy or the power grid drives the multi-stage compressor of the energy storage subunit to compress atmospheric air into high-pressure air. The intercooler and aftercooler recover the heat generated by the compressor. The compressed air is stored in the air storage cave. The high-pressure air in the air storage cave enters the combustion chamber through the pressure regulating valve, and burns with natural gas to produce high-temperature flue gas, which drives the first turbine to generate electricity. The regenerator recovers the waste heat of the flue gas and transfers it to the ORC unit.

[0089] In one possible embodiment, the ORC unit includes a first evaporator (EVAP), a second turbine, a first condenser (OC) and a pump (OP) device. The first evaporator includes a plurality of heat exchangers for evaporating the working fluid by using the residual heat energy. The second turbine is used to convert the heat energy of the evaporated working fluid into electrical energy to drive the generator to generate electricity. The first condenser is used to condense the working fluid. The pump device is used to pressurize the working fluid to circulate the working fluid.

[0090] Specifically, Figure 2As shown, the ORC unit includes two circulation subunits (ORC1 and ORC2). ORC1 uses multiple heat exchangers (IC1-IC6, AC) as the first evaporator to recover low-grade waste heat from the CAES unit to provide energy for ORC1. Its gaseous organic working fluid works in the expander (OT1) to drive related equipment to generate electricity. The condenser (OC1) and pump (OP1) maintain the circulation of organic working fluid in the ORC1 system. ORC2 is connected to the heat recovery unit (REC) to recover the heat from the generator (such as Figure 2 The waste heat is recovered from the exhaust gas discharged by the low pressure turbine (LPT) of the ORC2 (G) and converted into additional electrical energy, and its gaseous organic working fluid performs work in the expander (OT2) to generate electricity. The condenser (OC2) and the pump (OP2) maintain the circulation of the organic working fluid in the ORC2 system. In this way, the ORC unit contains two sets of independent working fluid cycles.

[0091] In a possible implementation, in the ORC unit, three regulating valves (V1, V2, V3) can be used to control the working fluid flow rate in the unit. Among them, the three-way valve (V1) gathers the high-pressure gaseous working fluid passing through the evaporator in the ORC1 and ORC2 subunits, and its outlet is connected to the expander (OT1 and OT2). After the low-pressure working fluid passing through the expander is condensed into liquid by the condenser, it is distributed to the ORC1 and ORC2 systems through two regulating valves (V2, V3), and the regulating valve V3 controls the working fluid flow rate in ORC1, and the regulating valve V2 controls the working fluid flow rate in ORC2.

[0092] In one possible embodiment, the ARS unit includes a solution heat exchanger (SHX), a desorber (DES), a second condenser (COND), a second evaporator EVAP and an absorber (ABS), wherein the solution heat exchanger is used to perform heat exchange with the resolver to provide residual heat energy for the resolver. The desorber is used to separate the refrigerant and the absorbent by the residual heat energy of the solution heat exchanger, and to transfer the separated water vapor to the second condenser. The second condenser is used to condense the water vapor to obtain liquid water, and to transfer the liquid water to the evaporator. The second evaporator is used to evaporate the liquid water to generate cold energy. The absorber is used to absorb the water vapor in the evaporator and generate a dilute solution.

[0093] Specifically, the absorbent of the ABS unit can be lithium bromide (LiBr) solution, and water (H2O) can be used as the refrigerant. Figure 2As shown, the ARS unit further recovers waste heat from the flue gas of the heat exchanger (SHX) and converts it into cold energy. The lithium bromide solution in the desorber (DES) exchanges heat with the exhaust gas from the heat exchanger (SHX), and the generated water vapor enters the condenser (COND); the water vapor is condensed into liquid water in the condenser (COND), and the liquid water enters the second evaporator (EVAP) through the throttle valve (VAL1). In the second evaporator (EVAP), the liquid water absorbs heat from the environment and evaporates to generate cold energy. The water vapor generated by the second evaporator (EVAP) is absorbed by the concentrated lithium bromide solution in the absorber (ABS) to generate a dilute lithium bromide solution. After the concentrated lithium bromide solution in the desorber (DES) exchanges heat with the dilute solution through the heat exchanger (SHX), it enters the absorber (ABS) through the throttle valve (VAL2), combines with the refrigerant vapor and is diluted into a dilute solution.

[0094] In a possible implementation, the waste heat contained in the waste gas generated by the energy-releasing subunit can be used to preheat the high-pressure air, and then the waste heat can be recovered by using the ORC2 unit, and then further recovered by using the ARS system. The waste heat generated by the operation of the CAES unit can be recovered by using the ORC1 unit.

[0095] In summary, in order to better explain the CCHP system provided by the exemplary embodiment of the present application, the operation process of the CCHP system will be explained:

[0096] In the energy storage phase, excess electricity generated by renewable energy or the grid drives a multi-stage compressor consisting of a low-pressure compressor (LPC) and six high-pressure compressors (HPC1-HPC6) to convert atmospheric air (as above) Figure 1 The stream 1 shown in the figure is compressed into high pressure air stored in the air storage cave (as shown above) Figure 1 The stream 15 shown is used to convert electrical energy into the internal energy of the air. The ORC1 unit recovers the waste heat of the multi-stage compressor through the intercooler (IC1-IC6) and the aftercooler (AC). Here, the functions of IC1-IC6 and AC are the same as those of the evaporator. The liquid working fluid (WF) absorbs the low-grade waste heat and vaporizes, and the saturated steam is further expanded through the expander (OT1) of the ORC1 unit. The low-pressure working fluid is liquefied in the first condenser (OC1) and then pressurized by the pump device (OP1). The above series of processes will be repeated in a closed cycle.

[0097] In the energy release stage, the regulating valve (REG) at the cave outlet is opened to supply gas to the combustion chamber (CC), and the hot flue gas generated enters the turbine (HPT and LPT) for expansion and power generation. However, the flue gas temperature at the turbine outlet is still high, and there is a lot of waste heat. The waste heat will be divided into two parts for recovery in succession, one part is used to drive the ORC2 unit to generate more electricity, and the other part is used to drive the ARS unit to generate cold energy, so that more waste heat can be recovered, thereby improving the round-trip efficiency (RTE) of the system. In the ARS unit, water can be used as a refrigerant and lithium bromide as an absorbent. The waste heat of the flue gas provides energy for the desorber (DES) to separate water from the lithium bromide solution, and the separated steam water is condensed in the condenser (COND) and then transferred to the second evaporator (EVAP). In the second evaporator (EVAP), liquid water absorbs heat and evaporates, producing a refrigeration effect. The water vapor generated in the second evaporator (EVAP) enters the absorber (ABS) and mixes with the concentrated lithium bromide solution to form a dilute lithium bromide solution. The water vapor generated in the desorber (DES) enters the second condenser (COND) and is condensed into liquid water, which then enters the second evaporator (EVAP) through the throttle valve (VAL2). The concentrated lithium bromide solution in the desorber (DES) exchanges heat with the dilute solution through the heat exchanger (SHX) and then enters the absorber (ABS) through the throttle valve (VAL1). The dilute solution enters the desorber (DES) to separate the refrigerant and the cycle begins again.

[0098] In a possible implementation, the working fluid (organic working fluid) of the ORC unit includes but is not limited to R600A, R600, R601, R245FA, R245CA, etc., which is not specifically limited in the embodiments of the present application.

[0099] In one possible implementation, the steady-state model of the charging and releasing process of the embodiment of the present application can be developed in a process simulation software, including but not limited to Aspen Plus, and the input parameters are considered based on the actual industrial operation conditions. During the simulation process, the working principles of each unit in the trigeneration system are first analyzed, and the corresponding modules are selected. According to the transfer state and direction of the fluid and energy in the system, each module is connected by logistics, work flow, and heat flow. After the model is built, enter the parameter setting page. First, set the physical parameters of the entire system, such as using the Peng-Robinson equation to calculate the thermodynamic properties, and then enter the logistics parameters, including the flow rate, pressure, temperature, etc. of the air, as well as the properties and flow rate of the working fluid. Set the parameters of each module, such as the pressure ratio and efficiency of the compressor, the efficiency of the turbine, the heat exchange efficiency of the heat exchanger, etc. After setting all the conditions, test run the entire process. After the operation is completed, obtain the corresponding operation report, and determine whether to continue to adjust the parameters according to the operation report, or directly extract the results after confirming that the operation is correct. In this way, through the developed steady-state model, the impact of different working fluids on the performance of the trigeneration system of the embodiment of the present application can be evaluated, such as Figure 3 As shown, the horizontal axis represents the OCR unit using five different working fluids: R600A, R600, R601, R245FA, and R245CA, and the vertical axis represents the performance evaluation parameters of the system under different working fluids, including the round-trip efficiency

[0100] The height of the bar graph in the figure shows the impact of different fluids on system performance under set working conditions. The higher the height of the bar graph, the better the overall performance of the working fluid, the higher the system operating efficiency or the higher the energy conversion rate.

[0101] Please refer to Figure 4 As shown, based on the same inventive concept, the embodiment of the present application further provides an optimization device 40 for a trigeneration system of cooling, heating and power, the device comprising:

[0102] The target determination unit 401 is used to determine the optimization target value of the trigeneration system.

[0103] The variable acquisition unit 402 is used to acquire the decision variables of the trigeneration system based on the optimization target value.

[0104] The system optimization unit 403 is used to perform iterative optimization processing on the decision variables based on the preset optimization strategy and in combination with the constraint conditions until the preset convergence conditions are met, thereby obtaining the optimization results corresponding to each decision variable.

[0105] Optionally, the optimization target value includes a round-trip efficiency value and an investment cost value, and the round-trip efficiency value represents the ratio of the total energy output by the system to the total energy input.

[0106] Optionally, the decision variables include: the internal combustion engine inlet temperature of the combustion chamber, the evaporation temperature of the circulation unit, the condensation temperature of the circulation unit, the mass flow rate of the working fluid, the desorber temperature of the refrigeration unit, the absorber temperature and the mass flow rate of the refrigeration unit.

[0107] Optionally, the constraints include: a first constraint of the internal combustion engine inlet temperature, and second constraints of the evaporation temperature and the condensation temperature.

[0108] For the convenience of description, the above parts are divided into each unit module (or module) according to the function and described separately. Of course, when implementing the present application, the functions of each unit (or module) can be implemented in the same one or more software or hardware. It can be understood by those skilled in the art that various aspects of the present application can be implemented as a system, method or program product. Therefore, various aspects of the present application can be specifically implemented in the following forms, namely: a complete hardware implementation method, a complete software implementation method (including firmware, microcode, etc.), or an implementation method combining hardware and software, which can be collectively referred to as "circuit", "module" or "system" here.

[0109] The device can be used to execute the methods shown in the various embodiments of the present application. Therefore, for the functions that can be implemented by the various functional modules of the device, reference can be made to the description of the aforementioned embodiments and no further details will be given.

[0110] See also Figure 5 As shown, based on the same technical concept, the embodiment of the present application also provides a computer device 50, which can be Figure 2 The trigeneration system shown may also be an optimization device for the trigeneration system. The computer device 50 may include a memory 501 and a processor 502 .

[0111] The so-called memory 501 is used to store computer programs executed by the processor 502. The memory 501 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function, etc.; the data storage area may store data created according to the use of the computer device, etc. The processor 502 may be a central processing unit (CPU), or a digital processing unit, etc. The specific connection medium between the above-mentioned memory 501 and the processor 502 is not limited in the embodiments of the present application. The embodiments of the present application are Figure 5 In the embodiment, the memory 501 and the processor 502 are connected via a bus 503. The bus 503 is connected to the processor 502 via a bus 503. Figure 5 The connection between other components is shown by bold lines, and is not intended to be limiting. The so-called bus 503 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0112] The memory 501 may be a volatile memory, such as a random-access memory (RAM); the memory 501 may also be a non-volatile memory, such as a read-only memory, a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD), or the memory 501 may be any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 501 may be a combination of the above memories.

[0113] The processor 502 is used to execute the optimization method of the trigeneration system executed by the device in each embodiment of the present application when calling the computer program stored in the so-called memory 501.

[0114] In some possible implementations, various aspects of the optimization method for a trigeneration system provided in the present application may also be implemented in the form of a program product, which includes a program code. When the program product is run on a computer device, the program code is used to enable the computer device to execute the steps of the optimization method for a trigeneration system according to various exemplary embodiments of the present application described above in this specification. For example, the computer device may execute the steps of each embodiment.

[0115] The program product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0116] The program product of the embodiment of the present application may adopt a portable compact disk read-only memory (CD-ROM) and include program code, and can be run on a computing device. However, the program product of the present application is not limited thereto. In the present application, the readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with a command execution system, device or device.

[0117] The readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, wherein the readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable signal medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with a command execution system, apparatus, or device.

[0118] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the foregoing.

[0119] Program code for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user equipment, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device via any type of network including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0120] It should be noted that, although several units or subunits of the device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided into multiple units to be embodied.

[0121] In addition, although the operations of the method of the present application are described in a specific order in the drawings, this does not require or imply that the operations must be performed in this specific order, or that all the operations shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0122] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0123] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0124] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An optimization method for a trigeneration system of cooling, heating and power, characterized in that: The method is applied to a cooling, heating and power trigeneration system, and the method comprises: Determine the optimization target value of the trigeneration system; Based on the optimization target value, obtaining decision variables of the trigeneration system; Based on the preset optimization strategy and in combination with the constraint conditions, the decision variables are iteratively optimized until the preset convergence conditions are met, and the optimization results corresponding to the decision variables are obtained; Among them, the trigeneration system of cooling, heating and power converts excess electricity into air internal energy through the energy storage and release unit in the energy storage stage, and stores the air internal energy, and releases the air internal energy in the energy release stage to obtain electrical energy; obtains the residual heat energy of the energy storage and release unit through the circulation unit, and converts the residual heat energy into electrical energy; and converts the residual heat energy of the energy storage and release unit into cold energy through the refrigeration unit to obtain cooling capacity.

2. The method according to claim 1, characterized in that: The optimization target value includes a round-trip efficiency value and an investment cost value, wherein the round-trip efficiency value represents the ratio of the total energy output by the system to the total energy input.

3. The method according to claim 1, characterized in that: The decision variables include: the internal combustion engine inlet temperature of the combustion chamber in the energy storage and release unit, the evaporation temperature of the circulation unit, the condensation temperature of the circulation unit, the mass flow rate of the working fluid, the desorber temperature of the refrigeration unit, the absorber temperature and the mass flow rate of the refrigeration unit.

4. The method according to claim 3, characterized in that: The constraint conditions include: a first constraint condition of the internal combustion engine inlet temperature, and second constraints of the evaporation temperature and the condensation temperature.

5. An optimization device for a trigeneration system of cooling, heating and power, characterized in that: The device comprises: A target determination unit, used to determine an optimization target value of the trigeneration system; A variable acquisition unit, used for acquiring a decision variable of the trigeneration system based on the optimization target value; The system optimization unit is used to iteratively optimize the decision variables based on a preset optimization strategy and in combination with constraint conditions until a preset convergence condition is met to obtain an optimization result corresponding to each decision variable; Among them, the trigeneration system of cooling, heating and power converts excess electricity into air internal energy through the energy storage and release unit in the energy storage stage, and stores the air internal energy, and releases the air internal energy in the energy release stage to obtain electrical energy; obtains the residual heat energy of the energy storage and release unit through the circulation unit, and converts the residual heat energy into electrical energy; and converts the residual heat energy of the energy storage and release unit into cold energy through the refrigeration unit to obtain cooling capacity.

6. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

7. A computer storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

8. A computer program product comprising computer program instructions, characterized in that When the computer program instructions are executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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