Waste heat recovery strategy analysis method and related equipment

Abstract

The invention discloses a waste heat recovery strategy analysis method and related equipment, and the method comprises the steps: firstly obtaining the flow and inlet temperature of each waste heat medium, and calculating the theoretical waste heat recovery power hour by hour in combination with environmental parameters and discharge temperature limitation; an energy conversion model is established based on the power and the equipment performance parameters, and a cascade framework is constructed according to the waste heat grade; and finally, by taking system energy efficiency maximization as a target, establishing an optimization model containing multiple types of constraints for solution, and obtaining an optimal equipment configuration and operation strategy. According to the cascade structure, efficient matching of waste heat and equipment is achieved, and recycling waste caused by mismatching is avoided; variable heat utilization requirements can be dynamically responded through hourly calculation and load constraint, and accurate space-time matching of waste heat and the requirements is achieved; the multi-constraint model enhances the multi-target optimization capability and makes up for the optimization deficiency in the prior art; the system planning process solves the problem of systematicness shortage of an existing method, the waste heat potential is effectively excavated, and the efficiency of the waste heat utilization comprehensive energy system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy recovery, more particularly to a waste heat recovery strategy analysis method and related equipment. BACKGROUND

[0002] With the rising of energy shortage and environmental protection demand, heat recovery technology has been widely used in industrial field. Current mainstream technologies include waste heat boiler, heat exchanger, organic Rankine cycle power generation and heat pump technology. These technologies can realize basic waste heat recovery in single working condition or simple system, and reduce energy consumption to a certain extent. However, in complex industrial systems such as large chemical plants, steel plants, cement plants and power plants, when building an efficient waste heat recovery and utilization system, the existing technology faces many bottlenecks that are difficult to break through.

[0003] Firstly, the characteristics of waste heat resources in complex industrial systems are extremely complex and diverse, with significant differences in temperature (heat grade), flow, continuity, spatial distribution and medium composition. The existing technology lacks a precise matching mechanism for this diversity, resulting in a large amount of waste heat that cannot be effectively recovered due to mismatch. Secondly, the heat demand in the system and the surrounding area changes dynamically, covering process heating, heating, refrigeration, power generation and other types. The existing technology cannot achieve efficient space-time matching of waste heat resources of different grades and time-varying heat demand, and cannot achieve matching utilization and recovery, which restricts the overall energy efficiency improvement. Finally, the existing planning method generally lacks systematic and multi-objective optimization capabilities, which cannot meet the demand for deep mining and maximum utilization of waste heat resources, and seriously restricts the efficiency of the waste heat utilization comprehensive energy system.

[0004] Therefore, the present application proposes a new waste heat recovery strategy analysis method to solve the defects of the existing technology and meet the urgent demand for deep utilization of waste heat resources. SUMMARY

[0005] The present application provides a waste heat recovery strategy analysis method and related equipment. By obtaining waste heat medium parameters and calculating theoretical waste heat recovery power, establishing an equipment energy conversion model, constructing a gradient utilization architecture according to the grade, establishing a multi-constraint optimization model with the goal of maximizing system energy efficiency and solving to obtain the optimal strategy, the defects of waste heat resource matching difficulty, poor heat demand response, weak multi-objective optimization, and insufficient planning system can be solved. The waste heat potential can be effectively tapped and the efficiency of the comprehensive energy system can be improved to meet the demand for deep utilization of waste heat.

[0006] A waste heat recovery strategy analysis method, comprising:

[0007] The flow and inlet temperature parameters of each waste heat medium are obtained respectively, and based on the preset environmental parameters and the discharge temperature limit, the theoretical waste heat recovery power of each waste heat medium is calculated by a theoretical waste heat recovery calculation formula.

[0008] establishing an energy conversion model between energy input and output of each waste heat recovery device based on the theoretical waste heat recovery power and inherent performance parameters of each waste heat recovery device;

[0009] constructing a cascade utilization architecture according to the grade of the waste heat medium to constrain the allocation path and available device set of the waste heat medium of different grades, and determining the allocation rule of the cascade utilization architecture as a medium-device matching constraint, wherein the high-grade waste heat medium is preferentially allocated to the high-grade energy conversion device;

[0010] based on the cascade utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, establishing a strategy optimization analysis model containing the medium-device matching constraint, the energy conversion balance constraint, the device operation boundary constraint and the user load demand constraint with the goal of maximizing the overall energy utilization efficiency of the system, and solving the model to obtain a waste heat recovery strategy containing the optimal device configuration and operation mode.

[0011] Optionally, the waste heat medium at least includes steam, flue gas and hot water.

[0012] the theoretical waste heat recovery calculation formula of the steam is:

[0013]

[0014] the theoretical waste heat recovery calculation formula of the flue gas is:

[0015]

[0016] the theoretical waste heat recovery calculation formula of the hot water is:

[0017]

[0018] wherein, S t is the theoretical waste heat recovery amount of the steam in the t period, m t st is the mass flow of the steam in the t period, h t in is the specific enthalpy of the steam before temperature and pressure change at t moment, h t amb is the specific enthalpy of the steam in the standard environment at t moment, F t is the theoretical waste heat recovery amount of the flue gas in the t period, v t f is the volume flow of the flue gas in the t period, c f is the average volume constant pressure heat capacity of the flue gas supply temperature, c’ f is the average volume constant pressure heat capacity of the flue gas exhaust temperature, T t is the average volume constant pressure heat capacity of the flue gas exhaust temperature, Tin T is the initial temperature of the flue gas in the tth period, T out W is the specified flue gas exhaust temperature, W t m is the theoretical waste heat recovery amount of hot water in the tth period, m t w c is the mass flow rate of hot water in the tth period, c w Cp is the constant-pressure specific heat of the hot fluid, T t in Tin is the inlet temperature of hot water in the tth period, T amb Tambient is the set ambient temperature.

[0019] Optionally, the waste heat recovery device at least includes an organic Rankine cycle generator set, an absorption heat pump, an absorption refrigerator, a waste heat recovery boiler, a heat exchanger, a compression heat pump, and a compression refrigerator;

[0020] The energy conversion model of the organic Rankine cycle generator set is:

[0021]

[0022] The energy conversion model of the absorption heat pump is:

[0023]

[0024] The energy conversion model of the absorption refrigerator is:

[0025]

[0026] The energy conversion model of the waste heat recovery boiler is:

[0027]

[0028] The energy conversion model of the heat exchanger is:

[0029]

[0030] The energy conversion model of the compression heat pump and the compression refrigerator is:

[0031]

[0032]

[0033] wherein, E t ORC Q is the net output power of the organic Rankine cycle generator set in the tth period, Q in,t ORC η is the equivalent heat power absorbed by the organic Rankine cycle from the waste heat source in the tth period, η heat η is the organic Rankine cycle thermal efficiency, ηrev For the heat recovery efficiency of the evaporator, H t AHP Q is the heating power of the absorption heat pump during time period t. in,t AHP C represents the equivalent heat power absorbed by the absorption heat pump from the waste heat source during time period t. t AbC Q is the cooling capacity of the absorption chiller during time period t. in,t AbC Let t be the equivalent heat power absorbed by the absorption chiller from the waste heat source during time period t, and COP be the heating performance coefficient of the absorption heat pump or the cooling performance coefficient of the absorption chiller. t WBOI F' is the equivalent thermal power of the steam produced by the waste heat recovery boiler during time period t. t WBOI η is the equivalent thermal power of the flue gas input during time period t. WBOI For the conversion efficiency of waste heat recovery boilers, W' t HEX_F F' is the equivalent thermal power of the hot water produced by the flue gas-water heat exchanger during time period t. t HEX_F η is the equivalent thermal power of the flue gas input during time period t. HEX_F For the conversion efficiency of the flue gas-water heat exchanger, W' t HEX_S S' is the equivalent thermal power of the hot water produced by the steam-water heat exchanger during time period t. t HEX_F η is the equivalent thermal power of the steam input during time period t. HEX_S For the conversion efficiency of a steam-water heat exchanger, H t HP E represents the heating power of the compression heat pump during time period t. t HP For the electrical power consumed by the compression heat pump during time period t, COP HP C is the coefficient of performance for a compression heat pump. t CC E represents the refrigeration capacity of the compressor chiller during time period t. t CC For the electrical power consumed by the compressor chiller during time period t, EER CC The coefficient of performance (COP) of a compression refrigeration machine.

[0034] Optionally, a tiered utilization architecture is constructed based on the grade of the waste heat medium to constrain the distribution paths and available equipment sets of waste heat media of different grades, and the distribution rules of the tiered utilization architecture are determined as medium-equipment matching constraints, including:

[0035] According to the temperature level of the waste heat medium, the waste heat medium is divided into high-grade waste heat medium, medium-grade waste heat medium and low-grade waste heat medium;

[0036] According to the grade, the distribution priority of the waste heat medium and the matching rule of the available equipment type are set, wherein the high-grade waste heat medium drives all types of waste heat recovery equipment, the medium-grade waste heat medium drives the medium-grade and low-grade types of waste heat recovery equipment, and the low-grade waste heat medium only drives the low-grade type of waste heat recovery equipment.

[0037] The binary variable is introduced to represent whether the equipment of each grade type can be driven by the waste heat medium of the corresponding grade, and the medium-equipment matching constraint of the cascade utilization architecture is formed.

[0038] Optionally, the establishment process of the strategy optimization analysis model comprises:

[0039] A system energy efficiency objective function is constructed to maximize the total energy utilization efficiency of the system.

[0040] An energy conversion balance constraint is established to ensure that the total input power of each waste heat medium is equal to the sum of the power utilized by each type of equipment and the power not utilized.

[0041] An equipment operation boundary constraint is established to limit the actual output of each waste heat recovery equipment to not exceed its rated capacity.

[0042] A user load demand constraint is established to ensure that the system output can meet the real-time load demand of the user.

[0043] The system energy efficiency objective function, the medium-equipment matching constraint, the energy conversion balance constraint, the equipment operation boundary constraint and the user load demand constraint are integrated to construct the strategy optimization analysis model.

[0044] Optionally, the energy conversion balance constraint is:

[0045]

[0046] The equipment operation boundary constraint is:

[0047]

[0048] The user load demand constraint is:

[0049]

[0050] Wherein, F t , S t , W t are the theoretical waste heat available power of the available flue gas, the available steam and the available hot water at t time, respectively, F tout , S t out , W t out Q i in,t Q j in,t Q k in,t S WBOI t W t HEX_F W t HEX_S l t l H t m C t n C l , P m , P n E t d E t HP , E t CC H t d C t d C

[0051] A waste heat recovery strategy analysis device, comprising:

[0052] A theoretical recovery calculation module is configured to obtain flow rate and inlet temperature parameters of each waste heat medium, and calculate theoretical waste heat recovery power of each waste heat medium based on preset environmental parameters and discharge temperature limits through a theoretical waste heat recovery calculation formula.

[0053] An energy conversion establishment module is configured to establish an energy conversion model between energy input and output of each waste heat recovery device based on the theoretical waste heat recovery power and inherent performance parameters of each waste heat recovery device.

[0054] A gradient architecture distribution module is configured to construct a gradient utilization architecture according to the grade of the waste heat medium, to constrain the distribution path and available device set of the waste heat medium of different grades, and to determine the distribution rule of the gradient utilization architecture as a medium-device matching constraint, wherein the high-grade waste heat medium is preferentially distributed to high-grade energy conversion devices.

[0055] A recovery strategy analysis module is configured to establish a strategy optimization analysis model containing the medium-device matching constraint, energy conversion balance constraint, device operation boundary constraint and user load demand constraint based on the gradient utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, to maximize the overall energy utilization efficiency of the system, and to solve the model to obtain a waste heat recovery strategy containing optimal device configuration and operation mode.

[0056] A waste heat recovery strategy analysis device, comprising a memory and a processor;

[0057] The memory is configured to store a program.

[0058] The processor is configured to execute the program to implement each step of the waste heat recovery strategy analysis method according to any one of the preceding embodiments.

[0059] A readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement each step of the waste heat recovery strategy analysis method according to any one of the preceding embodiments.

[0060] A computer program product comprising a computer program, wherein the computer program is executed by a processor to implement each step of the waste heat recovery strategy analysis method according to any one of the preceding embodiments.

[0061] It can be seen from the technical solutions that the method and related equipment for analyzing a waste heat recovery strategy provided by the embodiments of the present application specifically include: obtaining the flow and inlet temperature parameters of each waste heat medium respectively, combining preset environmental parameters and an outlet temperature limit, and obtaining the theoretical waste heat recovery power of each waste heat medium through a theoretical waste heat recovery calculation formula at each time; based on the theoretical waste heat recovery power and inherent performance parameters of each waste heat recovery device, an energy conversion model of device energy input and output is established; a cascade utilization architecture is constructed according to the grade of the waste heat medium, the distribution path and available device set of different grade waste heat media are determined, and the high grade waste heat medium is preferentially distributed to the high grade energy conversion device as a medium device matching constraint; taking the maximization of the overall energy utilization efficiency of the system as the target, combining the cascade utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, a strategy optimization analysis model is established and solved, which contains the medium device matching constraint, the energy conversion balance constraint, the device operation boundary constraint and the user load demand constraint, and finally the waste heat recovery strategy containing the optimal device configuration and operation mode is obtained.

[0062] The present application can solve the defects in the background art: first, the cascade utilization architecture and the medium device matching constraint can accurately cope with the problem of complex and diverse characteristics of waste heat resources, realize efficient matching of waste heat and devices through grade distribution, and avoid waste caused by mismatching; second, the theoretical waste heat recovery power is calculated at each time and incorporated into the user load demand constraint, which can dynamically respond to the variable heat demand such as process heating and heating, realize accurate space-time matching of waste heat resources and heat demand, and improve the effect of matching and cascade recovery; third, taking the maximization of the overall energy utilization efficiency as the target and the model covering multiple technical constraints can enhance the optimization ability under multiple target constraints and make up for the shortcomings of existing methods in the technical level of multi-objective optimization; fourth, from parameter acquisition, model establishment to architecture construction and optimization solving, a systematic planning process is formed to solve the problem of systematic deficiency of existing planning methods, effectively tap the potential of waste heat resources, significantly improve the efficiency of the waste heat utilization comprehensive energy system, and meet the urgent need for deep utilization of waste heat resources. BRIEF DESCRIPTION OF DRAWINGS

[0063] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings according to the provided drawings without creating any inventive labor.

[0064] Figure 1 The flowchart of the method for analyzing a waste heat recovery strategy disclosed in the embodiments of the present application;

[0065] Figure 2This is a schematic diagram of energy flow for a waste heat recovery and cascade utilization method disclosed in an embodiment of this application;

[0066] Figure 3 This is a schematic diagram of a waste heat recovery strategy analysis device disclosed in an embodiment of this application;

[0067] Figure 4 This is a hardware structure block diagram of a waste heat recovery strategy analysis device disclosed in an embodiment of this application. Detailed Implementation

[0068] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0069] This application can be used in a wide variety of general-purpose or special-purpose computing device environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor devices, distributed computing environments including any of the above devices, etc.

[0070] The following section introduces the solution proposed in this application. The technical solution is as follows, please refer to the text below for details.

[0071] Figure 1 This is a flowchart of a waste heat recovery strategy analysis method disclosed in an embodiment of this application.

[0072] like Figure 1 As shown, the method may include:

[0073] Step S1: Obtain the flow rate and inlet temperature parameters of each waste heat medium, and calculate the theoretical waste heat recovery power of each waste heat medium hourly based on the preset environmental parameters and discharge temperature limit using the theoretical waste heat recovery calculation formula.

[0074] Specifically, the preset environmental parameters include, but are not limited to, environmental temperature, atmospheric pressure and other external environmental physical quantities affecting the waste heat recovery process. Such parameters need to be set according to the actual working conditions of the waste heat recovery system to ensure that the calculation basis conforms to the actual application scenario. The discharge temperature limit is the maximum temperature threshold of the waste heat medium when it is discharged, which is determined according to the industry technical standards, the requirements of the subsequent process flow and the safety operation specifications of the equipment, so as to prevent energy waste or damage to the subsequent equipment caused by too high discharge temperature of the waste heat medium. The theoretical waste heat recovery calculation formula is a calculation formula derived based on the basic principles of thermodynamics combined with the specific heat capacity, density and other inherent physical properties of the waste heat medium. By substituting the obtained waste heat medium flow, inlet temperature, and preset environmental parameters and discharge temperature limit into the formula, the theoretical energy that can be recovered by each waste heat medium per unit time, i.e. the theoretical waste heat recovery power, can be accurately calculated. By using the hourly calculation method, the dynamic changes of the waste heat medium parameters at different times can be captured in real time, ensuring the timeliness and accuracy of the theoretical waste heat recovery power calculation results, and providing reliable basic data support for the subsequent analysis and optimization of the waste heat recovery system.

[0075] Further, the waste heat medium at least includes steam, flue gas and hot water.

[0076] The theoretical waste heat recovery calculation formula of the steam is:

[0077]

[0078] The theoretical waste heat recovery calculation formula of the flue gas is:

[0079]

[0080] The theoretical waste heat recovery calculation formula of the hot water is:

[0081]

[0082] Wherein, S t is the theoretical waste heat recovery amount of the steam in the t period, m t st is the mass flow of the steam in the t period, h t in is the specific enthalpy of the steam before the temperature and pressure change at t moment, h t amb is the specific enthalpy of the steam at t moment under standard environment, F t is the theoretical waste heat recovery amount of the flue gas in the t period, v t f is the volume flow of the flue gas in the t period, c f is the average volume constant pressure heat capacity of the flue gas at the supply temperature, c’ f is the average volume constant pressure heat capacity of the flue gas at the discharge temperature, Tt in T is the initial temperature of the flue gas in the tth period out W is the prescribed flue gas discharge temperature t m is the theoretical waste heat recovery amount of the hot water in the tth period t w c is the mass flow rate of the hot water in the tth period w T is the constant-pressure specific heat of the hot fluid t in T is the inlet temperature of the hot water in the tth period amb T is the set ambient temperature.

[0083] The waste heat medium at least includes steam, flue gas, and hot water. For the calculation of the theoretical waste heat recovery amount of steam, in the tth period, the mass flow rate of the steam in the period is used as the basis, combined with the specific enthalpy of the steam before the change of temperature and pressure at the tth moment, and the specific enthalpy of the steam at the tth moment under standard ambient conditions, the theoretical waste heat recovery amount of the steam in the tth period is obtained by the product operation of the difference between the two specific enthalpies and the mass flow rate of the steam in the period. For the calculation of the theoretical waste heat recovery amount of flue gas, in the tth period, the volume flow rate of the flue gas in the period is used as the basis, combined with the average volumetric constant-pressure heat capacity of the flue gas at the supply temperature, the initial temperature of the flue gas in the tth period, and the average volumetric constant-pressure heat capacity of the flue gas at the discharge temperature, the prescribed flue gas discharge temperature, the theoretical waste heat recovery amount of the flue gas in the tth period is obtained by calculating the difference between the heat values composed of the foregoing heat capacities and temperatures, and the product operation with the volume flow rate of the flue gas in the period. For the calculation of the theoretical waste heat recovery amount of hot water, in the tth period, the mass flow rate of the hot water in the period is used as the basis, combined with the constant-pressure specific heat of the hot fluid, and the difference between the inlet temperature of the hot water in the tth period and the set ambient temperature, the theoretical waste heat recovery amount of the hot water in the tth period is obtained by the product operation of the foregoing constant-pressure specific heat, temperature difference, and the mass flow rate of the hot water in the period.

[0084] Step S2, based on the theoretical waste heat recovery power and the inherent performance parameters of each waste heat recovery device, an energy conversion model between the energy input and output of each waste heat recovery device is established.

[0085] Specifically, the performance parameters inherent to the waste heat recovery device include rated power, energy conversion efficiency, minimum input energy threshold, maximum input energy threshold, heat dissipation loss coefficient, working temperature range, and other parameters that can reflect the energy conversion characteristics of the device. These parameters are determined by the device manufacturer based on device design standards and factory test results, and are key indicators for describing the actual performance of the device. In establishing the energy conversion model, the theoretical waste heat recovery power is first taken as the energy input variable of the device, and the available energy output by the device (such as electrical energy, thermal energy, mechanical energy, etc.) is taken as the energy output variable. Then, combined with the performance parameters of the device, the variation of the device output energy under different input energy levels is analyzed. For example, when the input energy is below the minimum input energy threshold of the device, the device cannot start or the conversion efficiency is greatly reduced; when the input energy is within the rated power range, the conversion efficiency is maintained at a relatively high and stable level; when the input energy exceeds the maximum input energy threshold, the device may run in overload, the conversion efficiency decreases and there is a safety risk. Through the quantitative description of the above rules, an energy conversion model that can accurately reflect the relationship between the input and output of the device is finally formed, providing a basis for device performance for subsequent system optimization analysis.

[0086] Step S3, constructing a cascade utilization architecture according to the grade of the waste heat medium to constrain the allocation path and available device set of the waste heat medium of different grades, and determining the allocation rule of the cascade utilization architecture as a medium-device matching constraint, wherein high-grade waste heat medium is preferentially allocated to high-grade energy conversion devices.

[0087] Specifically, Figure 2An energy flow schematic diagram of a waste heat recovery step utilization disclosed by an embodiment of the present application. The determination of the grade of the waste heat medium includes the thermodynamic parameters of the medium, such as temperature, pressure, and enthalpy value. In general, the higher the temperature, the greater the pressure, and the higher the enthalpy value, the higher the grade, and the higher the energy conversion efficiency that can be achieved. Conversely, the lower the grade. The construction process of the step utilization architecture is as follows: first, according to the high and low of the grade of the waste heat medium, multiple grade levels (such as high grade level, medium grade level, and low grade level) are divided, and then for each grade level, the type of waste heat recovery equipment (i.e. equipment set) that the waste heat medium of the level can adapt is determined. For example, the waste heat medium of the high grade level (such as high temperature flue gas and high pressure steam) can adapt to high grade energy conversion equipment (such as steam turbine, high temperature heat exchanger, waste heat power generation device, etc.), the waste heat medium of the medium grade level (such as medium temperature wastewater and medium pressure waste heat steam) can adapt to medium grade energy conversion equipment (such as medium temperature waste heat boiler, organic Rankine cycle power generation equipment, etc.), and the waste heat medium of the low grade level (such as low temperature cooling water and low temperature flue gas) can adapt to low grade energy conversion equipment (such as low temperature heat pump system and low temperature waste heat water heater, etc.). At the same time, the distribution path of each grade of waste heat medium is clear, that is, the high grade waste heat medium can flow to the high grade equipment set first, and if the high grade equipment set cannot completely consume the high grade waste heat medium, the remaining part can flow to the medium and low grade equipment set, while the medium and low grade waste heat medium cannot flow to the high grade equipment set, so as to avoid energy waste or equipment failure. The medium equipment matching constraint is determined based on the above grade level division, equipment set adaptation relationship and distribution path rule, so as to ensure that the waste heat resources can be utilized step by step and efficiently according to the grade, and to avoid the situation that the low grade waste heat occupies the high grade equipment resources, or the high grade waste heat flows to the low grade equipment without being fully utilized.

[0088] Step S4, based on the step utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, a strategy optimization analysis model containing the medium equipment matching constraint, the energy conversion balance constraint, the equipment operation boundary constraint and the user load demand constraint is established to maximize the overall energy utilization efficiency of the system, and is solved to obtain a waste heat recovery strategy containing the optimal equipment configuration and operation mode.

[0089] Specifically, based on the step utilization architecture constructed in step S3, the energy conversion model established in step S2 and the theoretical waste heat recovery power calculated in step S1, a strategy optimization analysis model containing the medium equipment matching constraint, the energy conversion balance constraint, the equipment operation boundary constraint and the user load demand constraint is established to maximize the overall energy utilization efficiency of the waste heat recovery system, and the model is solved to finally obtain a waste heat recovery strategy containing the optimal equipment configuration scheme and the optimal operation mode.

[0090] Specifically, the specific content of each constraint condition in the strategy optimization analysis model is as follows: first, the medium equipment matching constraint, that is, strictly following the allocation rule in the step S3 determined gradient utilization architecture, ensuring that the matching of the waste heat medium and the waste heat recovery equipment meets the requirement of grade adaptation and path constraint; second, the energy conversion balance constraint, based on the principle of energy conservation, requiring the input energy of each waste heat recovery equipment (i.e. the theoretical waste heat recovery power from the waste heat medium) to maintain balance with the available energy output by the equipment and the energy loss in the equipment operation process (such as heat loss, mechanical loss, etc.), avoiding the situation of energy non-conservation; third, the equipment operation boundary constraint, according to the design standard and safe operation requirement of each waste heat recovery equipment, the allowed range of parameters such as temperature, pressure, load rate, start-stop state of the equipment during operation is determined, for example, the equipment load rate should not be lower than the minimum allowable load rate (to prevent low-efficiency operation of the equipment), should not be higher than the maximum allowable load rate (to prevent damage of the equipment due to overload), the equipment working temperature should not exceed the design temperature interval, etc.; fourth, the user load demand constraint, ensuring that the total amount of available energy (such as total power generation, total heat supply, etc.) generated by each waste heat recovery equipment in the model output can meet the actual load demand of the user in production, life and other scenarios, avoiding the situation of insufficient energy supply. In the model solving process, an algorithm suitable for multi-constraint condition and multi-objective optimization (such as linear programming algorithm, genetic algorithm, particle swarm optimization algorithm, etc.) is adopted, taking the maximum system overall energy utilization efficiency as the objective function, and performing multi-variable optimization calculation on the equipment configuration scheme (such as type selection and quantity determination of the equipment) and operation mode (such as start-stop control strategy, load distribution ratio, distribution amount of the waste heat medium among different equipment, etc.) in the waste heat recovery system. By solving the strategy optimization analysis model, the equipment configuration scheme and operation mode that make the system overall energy utilization efficiency the highest can be screened out under the premise of meeting all the constraint conditions, and then the final waste heat recovery strategy is formed, providing optimization guidance for the actual construction and operation of the waste heat recovery system.

[0091] From the above technical solutions, it can be seen that the application embodiment provides a waste heat recovery strategy analysis method and related equipment, which specifically comprises: obtaining the flow and inlet temperature parameters of each waste heat medium respectively, combining the preset environmental parameters and the discharge temperature limit, and obtaining the theoretical waste heat recovery power of each waste heat medium through the theoretical waste heat recovery calculation formula at each time; based on the theoretical waste heat recovery power and the inherent performance parameters of each waste heat recovery device, an energy conversion model of device energy input and output is established; a cascade utilization architecture is constructed according to the grade of the waste heat medium, the distribution path and the available device set of the waste heat medium of different grades are determined, and the high-grade waste heat medium is preferentially distributed to the high-grade energy conversion device as a medium device matching constraint; taking the maximization of the overall energy utilization efficiency of the system as the target, combining the cascade utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, a strategy optimization analysis model is established and solved, which contains the medium device matching constraint, the energy conversion balance constraint, the device operation boundary constraint and the user load demand constraint, and finally the waste heat recovery strategy containing the optimal device configuration and operation mode is obtained.

[0092] The application can solve the defects in the background art: first, the cascade utilization architecture and the medium device matching constraint can accurately cope with the problem of complex and diverse characteristics of waste heat resources, realize efficient matching of waste heat and devices through grade distribution, and avoid waste caused by mismatching; second, the theoretical waste heat recovery power is calculated at each time and incorporated into the user load demand constraint, which can dynamically respond to variable heat demand such as process heating and heating, realize accurate space-time matching of waste heat resources and heat demand, and improve the effect of matching and cascade recovery; third, taking the maximization of the overall energy utilization efficiency as the target and the model covering multiple technical constraints can enhance the optimization ability under multiple target constraints and make up for the shortcomings of existing methods in multi-objective optimization at the technical level; fourth, from parameter acquisition, model establishment to architecture construction and optimization solving, a systematic planning process is formed to solve the problem of systematic deficiency of existing planning methods, effectively tap the potential of waste heat resources, significantly improve the efficiency of the waste heat utilization comprehensive energy system, and meet the urgent need for deep utilization of waste heat resources.

[0093] In some embodiments of the application, the waste heat recovery device at least includes an organic Rankine cycle generator set, an absorption heat pump, an absorption refrigeration machine, a waste heat recovery boiler, a heat exchanger, a compression heat pump and a compression refrigeration machine.

[0094] The net power output of the organic Rankine cycle generator set after absorbing heat from the waste heat source depends on the absorbed equivalent heat power, multiplied by the thermal efficiency of the organic Rankine cycle itself and the heat recovery efficiency of the evaporator. Simply put, the absorbed waste heat is converted into electric energy output through the efficiency of the cycle and the evaporator. The energy conversion model of the organic Rankine cycle generator set is:

[0095]

[0096] The heating capacity of the absorption heat pump is how much equivalent heat power is absorbed from the waste heat source, multiplied by the heating coefficient of performance (COP). The higher the COP, the more heat is produced under the same heat absorption. The energy conversion model of the absorption heat pump is:

[0097]

[0098] The refrigeration capacity of the absorption refrigerator is how much equivalent heat power is absorbed from the waste heat source, multiplied by the refrigeration coefficient of performance (COP). The higher the COP, the more cold is produced under the same heat absorption. The energy conversion model of the absorption refrigerator is:

[0099]

[0100] The amount of steam heat that the waste heat recovery boiler can produce after the flue gas with heat enters the boiler depends on the equivalent heat power of the input flue gas, multiplied by the conversion efficiency of the boiler. The higher the efficiency, the greater the proportion of flue gas heat converted into steam heat. The energy conversion model of the waste heat recovery boiler is:

[0101]

[0102] The heat exchanger includes a flue gas-water heat exchanger and a steam-water heat exchanger. In the flue gas-water heat exchanger, the heat of the flue gas is transferred to hot water, and the amount of hot water heat that can be produced depends on the equivalent heat power of the input flue gas multiplied by the conversion efficiency of the heat exchanger. In the steam-water heat exchanger, the heat of the steam is transferred to hot water, and the amount of hot water heat that can be produced depends on the equivalent heat power of the input steam multiplied by the conversion efficiency of the heat exchanger. The energy conversion model of the heat exchanger is:

[0103]

[0104] The compression heat pump relies on consuming electric energy to produce heat, and the amount of heat that can be produced is the electric power consumed multiplied by the heating coefficient of performance. The higher the heating coefficient of performance, the more efficient the electric heating. The compression refrigerator relies on consuming electric energy to produce cold, and the amount of cold that can be produced is the electric power consumed multiplied by the refrigeration coefficient of performance. The higher the refrigeration coefficient of performance, the more energy-efficient the electric refrigeration.

[0105] The energy conversion model of the compression heat pump and the compression refrigerator is:

[0106]

[0107]

[0108] Wherein, E t ORC is the net output power of the organic Rankine cycle generator set for t period, Qin,t ORC COP is the equivalent heat power absorbed by the organic Rankine cycle from the waste heat source over the period t, η heat η is the thermal efficiency of the organic Rankine cycle, H rev H is the heat recovery efficiency of the evaporator, H t AHP Q is the heating power of the absorption heat pump over the period t, C in,t C is the equivalent heat power absorbed by the absorption heat pump from the waste heat source over the period t, η AHP η is the equivalent heat power absorbed by the absorption heat pump from the waste heat source over the period t, COP is the heating performance coefficient of the absorption heat pump or the cooling performance coefficient of the absorption chiller, S’ t AbC Q is the cooling power of the absorption chiller over the period t, COP is the equivalent heat power absorbed by the absorption chiller from the waste heat source over the period t, COP is the heating performance coefficient of the absorption heat pump or the cooling performance coefficient of the absorption chiller, S’ in,t AbC F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ t WBOI F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ t WBOI F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ WBOI t F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ HEX_F t F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ HEX_F HEX_F F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ t HEX_S F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ t HEX_F F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ HEX_S t F’ is the equivalent heat power of steam produced by the waste heat recovery boiler over the period t, W’ is the conversion efficiency of the waste heat recovery boiler, W’ HP t E is the heating power of the compression heat pump over the period t, COP is the equivalent heat power consumed by the compression heat pump over the period t, COP is the heating performance coefficient of the compression heat pump, C HP HP E is the heating power of the compression heat pump over the period t, COP is the equivalent heat power consumed by the compression heat pump over the period t, COP is the heating performance coefficient of the compression heat pump, C t CC E is the heating power of the compression heat pump over the period t, COP is the equivalent heat power consumed by the compression heat pump over the period t, COP is the heating performance coefficient of the compression heat pump, C t CC E is the heating power of the compression heat pump over the period t, COP is the equivalent heat power consumed by the compression heat pump over the period t, COP is the heating performance coefficient of the compression heat pump, C CC E is the heating power of the compression heat pump over the period t, COP is the equivalent heat power consumed by the compression heat pump over the period t, COP is the heating performance coefficient of the compression heat pump, C

[0109] ​In some embodiments of the present application, step S3 is introduced to construct a cascade utilization architecture according to the grade of the residual heat medium, to constrain the allocation path and available device set of the residual heat medium of different grades, and to determine the allocation rule of the cascade utilization architecture as a medium-device matching constraint. Specifically, it can include:

[0110] Step S31 divides the residual heat medium into high-grade residual heat medium, medium-grade residual heat medium and low-grade residual heat medium according to the temperature level.

[0111] Specifically, in combination with the internal correlation characteristics of the energy grade and temperature of the residual heat medium, the residual heat medium is graded according to the grade: the high-grade residual heat medium refers to the residual heat carrier with a higher temperature interval, such as high-temperature steam and high-temperature flue gas, etc. Such medium has a higher energy grade due to a higher temperature. The temperature of the medium-grade residual heat medium is in the middle interval, such as medium-temperature exhaust gas and medium-pressure hot water, etc. Its energy grade is relatively moderate. The temperature of the low-grade residual heat medium is in the lower interval, such as low-temperature cooling water and low-temperature exhaust gas, etc. Its energy grade is relatively low. Through such temperature interval division, the energy grade level of different residual heat media can be clearly defined, laying a foundation for the subsequent construction of the cascade utilization architecture.

[0112] Step S32 sets the allocation priority of the residual heat medium and the matching rule of the available device type according to the grade, wherein the high-grade residual heat medium drives all types of residual heat recovery devices, the medium-grade residual heat medium drives medium-grade and low-grade types of residual heat recovery devices, and the low-grade residual heat medium only drives low-grade types of residual heat recovery devices.

[0113] Specifically, based on the energy characteristics of each grade of waste heat medium, the following matching rules are determined: high-grade waste heat medium can provide sufficient energy for all types of waste heat recovery equipment (including organic Rankine cycle generator set, absorption heat pump, absorption refrigerator, waste heat recovery boiler, heat exchanger, compression heat pump and compression refrigerator, etc.) due to its high energy grade, which can be used for efficient conversion of high-grade energy (such as driving waste heat power generation equipment to realize power output), and can also be compatible with the energy conversion process of medium and low-grade equipment (such as supplying heat to low-grade heat supply scenarios through heat exchangers); the energy grade of medium-grade waste heat medium can support the operation of medium-grade waste heat recovery equipment (such as organic Rankine cycle generator set with medium-temperature waste heat, medium-temperature waste heat boiler, etc.), and can also drive low-grade waste heat recovery equipment (such as heat exchangers and absorption heat pumps using medium-temperature waste heat), but due to the limitation of energy grade, it cannot drive equipment that requires high-grade energy input (such as high-parameter waste heat power generation equipment that relies on high-temperature heat source); low-grade waste heat medium has low energy grade, and can only be matched with low-grade waste heat recovery equipment, such as various heat exchangers (for direct heat exchange utilization of low-grade heat), compression heat pumps (operating in low-grade waste heat adaptation mode), etc., and cannot drive high-grade or medium-grade equipment that requires high energy grade (such as absorption refrigerator that requires high-temperature heat source, high-grade driven waste heat recovery boiler, etc.). Through the matching rules, the distribution direction and equipment adaptation range of different grade waste heat media can be standardized, and the rational utilization of energy cascade can be guaranteed.

[0114] Step S33, by introducing binary variables to represent whether each grade of equipment can be driven by the corresponding grade of waste heat medium, the medium-equipment matching constraint of the cascade utilization architecture is formed.

[0115] Specifically, to quantify the matching rules set in step S32 into model-recognizable constraints, binary identification variables are introduced to represent the matching relationship between the residual heat medium and the residual heat recovery equipment. When a residual heat medium of a certain grade can drive a specific type of residual heat recovery equipment, the binary variable takes the value of 1; when it cannot drive, the value is 0. For example, for a high-grade residual heat medium and an organic Rankine cycle generator set, if the high-grade residual heat medium can drive the set, the corresponding binary variable is 1, otherwise it is 0; for a low-grade residual heat medium and an absorption heat pump (since the absorption heat pump usually needs medium-high grade driving, low grade cannot drive), the corresponding binary variable is 0. Through the introduction and assignment of such binary variables, the matching rules of high-grade residual heat medium driving all types of equipment, medium-grade residual heat medium driving medium-grade and low-grade type equipment, and low-grade residual heat medium only driving low-grade type equipment are converted into quantified constraints, thereby forming the medium-equipment matching constraints under the cascade utilization architecture, ensuring that the matching of residual heat medium and equipment strictly follows the pre-set grade adaptation requirements in the subsequent strategy optimization analysis, providing constraint support for the optimization of overall energy utilization efficiency of the system.

[0116] In some embodiments of the present application, the establishment process of the strategy optimization analysis model described in step S4 is introduced, which can specifically include:

[0117] Step S41, a system energy efficiency objective function is constructed with the goal of maximizing the total energy utilization efficiency of the system.

[0118] Specifically, the ratio of the total amount of energy effectively utilized by the system in unit time to the total power input by each residual heat medium is taken as the quantitative indicator of the total energy utilization efficiency of the system to construct the system energy efficiency objective function. The total amount of energy effectively utilized includes electric energy, useful heat energy, and useful cold energy converted by various types of residual heat recovery equipment, which can be utilized by users or subsequent processes; the total power input by each residual heat medium is the sum of the theoretical residual heat power carried by all residual heat media (such as flue gas, steam, hot water, etc.) participating in recovery. Through the hourly calculation of the ratio of the total amount of energy effectively utilized to the total power input at different times and the analysis requirements of the time dimension (such as cumulative average, etc.), the system energy efficiency objective function with the goal of maximizing the ratio is finally formed, providing target guidance for subsequent optimization.

[0119] Step S42, an energy conversion balance constraint is established to ensure that the total power input by each residual heat medium is equal to the sum of the power utilized by each type of equipment and the power not utilized.

[0120] Specifically, for different waste heat media such as flue gas, steam and hot water, the energy balance relationship is established: for flue gas medium, the total power input at a certain moment (i.e. the theoretical waste heat available power of flue gas) is equal to the sum of the flue gas waste heat power utilized by all devices utilizing flue gas waste heat (such as flue gas type organic Rankine cycle generator set, flue gas type absorption heat pump, etc.) at that moment, plus the heat power of flue gas not utilized at that moment; for steam medium, the total power input at a certain moment (i.e. the sum of the theoretical waste heat available power of steam and the heat power of steam produced by the waste heat recovery boiler) is equal to the sum of the steam waste heat power utilized by all devices utilizing steam waste heat (such as steam type organic Rankine cycle generator set, steam type absorption heat pump, etc.) at that moment, plus the heat power of steam not utilized at that moment; for hot water medium, the total power input at a certain moment (i.e. the sum of the theoretical waste heat available power of hot water, the heat power of hot water produced by the flue gas-water heat exchanger and the heat power of hot water produced by the steam-water heat exchanger) is equal to the sum of the hot water waste heat power utilized by all devices utilizing hot water waste heat (such as hot water type organic Rankine cycle generation device, hot water type absorption heat pump, etc.) at that moment, plus the heat power of hot water not utilized at that moment. By establishing the above energy balance relationship for different waste heat media, it is ensured that the input power and the output power (including utilized and not utilized) are conserved in the energy conversion process, and the energy level constraint basis is provided for the model.

[0121] The energy conversion balance constraint is:

[0122]

[0123] Step S43, establish device operation boundary constraint to limit the actual output of each waste heat recovery device not to exceed its rated capacity.

[0124] Specifically, for various types of waste heat recovery equipment such as power generation equipment, heating equipment, and refrigeration equipment, the range constraints of their operation output are set respectively: for power generation equipment (such as flue gas type, steam type, hot water type organic Rankine cycle generator set, etc.), the power generation power at a certain moment needs to meet the condition of "not less than 0, at the same time not more than the rated capacity of the equipment", so as to ensure that the power generation power is within the output interval that the equipment can stably operate; for heating equipment (such as flue gas type, steam type, hot water type absorption heat pump and compression heat pump, etc.), the heating power at a certain moment needs to meet the condition of "not less than 0, at the same time not more than the rated capacity of the equipment", so as to ensure that the heating power is within the output range that the equipment can safely operate; for refrigeration equipment (such as flue gas type, steam type, hot water type absorption refrigeration machine and compression refrigeration machine, etc.), the refrigeration power at a certain moment needs to meet the condition of "not less than 0, at the same time not more than the rated capacity of the equipment", so as to ensure that the refrigeration power is within the output interval that the equipment can stably operate. Through such boundary constraints, the situation that the equipment fails or operates inefficiently due to the output exceeding the rated capacity is avoided, and the reliability of the equipment operation is ensured.

[0125] The equipment operation boundary constraint is:

[0126]

[0127] Step S44, establish user load demand constraints to ensure that the system output can meet the real-time load demand of the user.

[0128] Specifically, from the perspective of user load demand of electric energy, heat energy and cold energy, the matching constraint between system output and user demand is established: for electric load, the sum of power generation power of all power generation equipment at a certain moment needs to equal the sum of electric power demand of the user at that moment and the power consumption of electric power consumption equipment such as compression heat pump and compression refrigeration machine, so as to ensure that electric energy can meet the user's demand for electricity and provide support for the operation of electric power consumption equipment; for heat load, the sum of heating power of all heating equipment at a certain moment needs to equal the heat demand power of the user at that moment, so as to ensure that the user's heat demand is fully met; for cold load, the sum of refrigeration power of all refrigeration equipment at a certain moment needs to equal the cold demand power of the user at that moment, so as to ensure that the user's cold demand is effectively supplied. Through this constraint, the output of the system and the real-time load demand of the user are precisely matched, and the pertinence of energy utilization is improved.

[0129] The user load demand constraint is:

[0130]

[0131] Wherein, F t , S t , W trespectively the theoretical waste heat available power of the available flue gas, available steam and available hot water at time t, F t out , S t out , W t out respectively the unused heat power of the available flue gas, available steam and available hot water at time t, Q i in,t is the waste heat power of i equipment using flue gas at time t, i including flue gas type organic Rankine cycle generator set, flue gas type absorption heat pump, flue gas type absorption refrigerator, waste heat recovery boiler and flue gas-water heat exchanger, Q j in,t is the waste heat power of j equipment using steam at time t, j including steam type organic Rankine cycle generator set, steam type absorption heat pump, steam type absorption refrigerator and steam-water heat exchanger, Q k in,t is the waste heat power of k equipment using hot water at time t, k including hot water type organic Rankine cycle power generation equipment, hot water type absorption heat pump, hot water type absorption refrigerator, S WBOI t is the steam heat power output by the waste heat recovery boiler at time t, W t HEX_F is the hot water heat power output by the flue gas-water heat exchanger at time t, W t HEX_S is the hot water heat power output by the steam-water heat exchanger at time t, l is the power generation equipment including flue gas type, steam type and hot water type organic Rankine cycle generator set, m is the heating equipment including flue gas type, steam type, hot water type absorption heat pump and compression heat pump, n is the refrigeration equipment including flue gas type, steam type, hot water type absorption refrigerator and compression refrigerator, E t l is the power generation power of the power generation equipment at time t, H t m is the heating power of the heating equipment at time t, C t n is the refrigeration power of the refrigeration equipment at time t, P l , P m , P n respectively the rated capacity value of each power generation equipment, heating equipment and refrigeration equipment, E t d is the user electricity demand power at time t, E t HP , E t CC is the power consumption of the compression heat pump and compression refrigerator at time t, H t d is the user heat demand power at time t, C td is the user cold demand power at time t.

[0132] Step S45, integrating the system energy efficiency objective function, the medium device matching constraint, the energy conversion balance constraint, the device operation boundary constraint and the user load demand constraint, to build the strategy optimization analysis model.

[0133] Specifically, the system energy efficiency objective function built in step S41 is integrated with the medium device matching constraint (constraint rule embodied by means such as binary variable, etc.) of the different grade waste heat medium matched with the corresponding device determined in step S3, the energy conversion balance constraint of step S42, the device operation boundary constraint of step S43, and the user load demand constraint of step S44. Taking the system energy efficiency objective function as the optimization target, taking the other constraints as the conditions that must be met in the optimization process, and by means of mathematical modeling methods such as linear programming or nonlinear programming, these targets and constraints are integrated into a unified model framework, and finally a strategy optimization analysis model is formed. The model can be solved by an optimization algorithm under the premise of meeting all the constraint conditions, and then the device configuration scheme and device operation mode that maximize the total energy utilization efficiency of the system are obtained, thereby providing a complete analysis tool for the optimization of the waste heat recovery system.

[0134] Next, a waste heat recovery strategy analysis device provided by the embodiments of the present application is described. The waste heat recovery strategy analysis device described below can be correspondingly referred to the waste heat recovery strategy analysis method described above.

[0135] Referring to Figure 3 , Figure 3 is a schematic diagram of a waste heat recovery strategy analysis device disclosed by the embodiments of the present application.

[0136] As Figure 3 shown, the waste heat recovery strategy analysis device can include:

[0137] The theoretical recovery calculation module 110 is configured to acquire the flow rate and inlet temperature parameters of each waste heat medium, and based on the preset environmental parameters and discharge temperature limit, calculate the theoretical waste heat recovery power of each waste heat medium by a theoretical waste heat recovery calculation formula;

[0138] The energy conversion establishment module 120 is configured to establish an energy conversion model between the energy input and output of each waste heat recovery device based on the theoretical waste heat recovery power and the inherent performance parameters of each waste heat recovery device.

[0139] The gradient architecture distribution module 130 is configured to construct a gradient utilization architecture according to the grade of the waste heat medium, to constrain the distribution path and the available device set of the waste heat medium of different grades, and to determine the distribution rule of the gradient utilization architecture as a medium-device matching constraint, wherein the high-grade waste heat medium is preferentially distributed to the high-grade energy conversion device.

[0140] The recovery strategy analysis module 140 is configured to establish a strategy optimization analysis model containing the medium-device matching constraint, the energy conversion balance constraint, the device operation boundary constraint and the user load demand constraint based on the gradient utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, to maximize the overall energy utilization efficiency of the system as a target, and to solve the model to obtain a waste heat recovery strategy containing the optimal device configuration and operation mode.

[0141] As can be seen from the above technical solutions, the waste heat recovery strategy analysis method and related device provided by the embodiments of the present application specifically include: obtaining the flow and inlet temperature parameters of each waste heat medium respectively, obtaining the theoretical waste heat recovery power of each waste heat medium through a theoretical waste heat recovery calculation formula at each time by combining the preset environmental parameters and the exhaust temperature limit; establishing an energy conversion model of the energy input and output of the device based on the theoretical waste heat recovery power and the inherent performance parameters of each waste heat recovery device; constructing a gradient utilization architecture according to the grade of the waste heat medium, to clearly define the distribution path and the available device set of the waste heat medium of different grades, and to preferentially distribute the high-grade waste heat medium to the high-grade energy conversion device as a medium-device matching constraint; maximizing the overall energy utilization efficiency of the system as a target, combining the gradient utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, establishing a strategy optimization analysis model containing the medium-device matching constraint, the energy conversion balance constraint, the device operation boundary constraint and the user load demand constraint and solving the model, and finally obtaining a waste heat recovery strategy containing the optimal device configuration and operation mode.

[0142] The application can solve the defects in the background art: first, the cascade utilization architecture is matched with the medium equipment constraints, accurately coping with the complex and diverse characteristics of waste heat resources, and achieving efficient matching of waste heat and equipment through grade allocation to avoid waste caused by mismatch; second, the theoretical waste heat recovery power is calculated by time and is included in the user load demand constraints, which can dynamically respond to the variable heat demand of process heating, heating, etc., to realize accurate space-time matching of waste heat resources and heat demand, improve the effect of matching and cascade recovery, and enhance the optimization ability under multi-objective constraints; fourth, from parameter acquisition, model establishment to architecture construction and optimization solution, a systematic planning process is formed to solve the problem of systematic deficiency of existing planning methods, effectively tap the potential of waste heat resources, significantly improve the efficiency of waste heat utilization comprehensive energy system, and meet the urgent need for deep utilization of waste heat resources.

[0143] Optionally, the waste heat medium at least includes steam, flue gas, and hot water.

[0144] The theoretical waste heat recovery calculation formula of the steam is:

[0145]

[0146] The theoretical waste heat recovery calculation formula of the flue gas is:

[0147]

[0148] The theoretical waste heat recovery calculation formula of the hot water is:

[0149]

[0150] Wherein, S t is the theoretical waste heat recovery amount of steam in the t period, m t st is the mass flow rate of steam in the t period, h t in is the specific enthalpy of steam before temperature and pressure change at t time, h t amb is the specific enthalpy of steam in the standard environment at t time, F t is the theoretical waste heat recovery amount of flue gas in the t period, v t f is the volume flow rate of flue gas in the t period, c f is the average volume constant pressure heat capacity of flue gas supply temperature, c’ f is the average volume constant pressure heat capacity of flue gas exhaust temperature, T t in is the initial temperature of flue gas in the t period, Tout W is the specified flue gas exhaust temperature, t W is the theoretical waste heat recovery amount of hot water in the t period, m t w W is the mass flow rate of hot water in the t period, c w W is the constant-pressure specific heat of the heat fluid, T t in W is the inlet temperature of hot water in the t period, T amb W is the set ambient temperature.

[0151] Optionally, the waste heat recovery device at least includes an organic Rankine cycle generator set, an absorption heat pump, an absorption refrigerator, a waste heat recovery boiler, a heat exchanger, a compression heat pump, and a compression refrigerator;

[0152] The energy conversion model of the organic Rankine cycle generator set is:

[0153]

[0154] The energy conversion model of the absorption heat pump is:

[0155]

[0156] The energy conversion model of the absorption refrigerator is:

[0157]

[0158] The energy conversion model of the waste heat recovery boiler is:

[0159]

[0160] The energy conversion model of the heat exchanger is:

[0161]

[0162] The energy conversion model of the compression heat pump and the compression refrigerator is:

[0163]

[0164]

[0165] Wherein, E t ORC W is the net output power of the organic Rankine cycle generator set in the t period, Q in,t ORC W is the equivalent heat power absorbed by the organic Rankine cycle from the waste heat source in the t period, η heat W is the organic Rankine cycle thermal efficiency, η rev W is the heat recovery efficiency of the evaporator, H tAHP Q is the heating power of the absorption heat pump for the time period t in,t AHP C is the equivalent heat power absorbed by the absorption heat pump from the waste heat source for the time period t t AbC Q is the refrigeration power of the absorption refrigerator for the time period t in,t AbC C is the equivalent heat power absorbed by the absorption refrigerator from the waste heat source for the time period t COP is the coefficient of performance of the absorption heat pump or the coefficient of performance of the absorption refrigerator, S’ t WBOI F’ is the equivalent heat power of steam produced by the waste heat recovery boiler for the time period t t WBOI η is the equivalent heat power of the input flue gas for the time period t WBOI W’ is the conversion efficiency of the waste heat recovery boiler t HEX_F F’ is the equivalent heat power of hot water produced by the flue gas-water heat exchanger for the time period t t HEX_F η is the equivalent heat power of the input flue gas for the time period t HEX_F W’ is the conversion efficiency of the flue gas-water heat exchanger t HEX_S S’ is the equivalent heat power of hot water produced by the steam-water heat exchanger for the time period t t HEX_F η is the equivalent heat power of the input steam for the time period t HEX_S H is the conversion efficiency of the steam-water heat exchanger t HP E is the heating power of the compression heat pump for the time period t t HP C is the coefficient of performance of the compression heat pump HP C is the heating coefficient of performance of the compression heat pump t CC E is the refrigeration power of the compression refrigerator for the time period t t CC EER is the coefficient of performance of the compression refrigerator CC EER is the coefficient of performance of the compression refrigerator.

[0166] Optionally, a cascade utilization architecture is constructed according to the grade of the waste heat medium, to constrain the distribution path and available device set of the waste heat medium of different grades, and the distribution rule of the cascade utilization architecture is determined as a medium-device matching constraint, including:

[0167] The waste heat medium is divided into high-grade waste heat medium, medium-grade waste heat medium and low-grade waste heat medium according to the temperature level of the waste heat medium;

[0168] The distribution priority of the residual heat medium and the matching rule of the available equipment type are set according to the grade, wherein the high-grade residual heat medium drives all types of residual heat recovery equipment, the medium-grade residual heat medium drives the medium-grade and low-grade types of residual heat recovery equipment, and the low-grade residual heat medium only drives the low-grade type of residual heat recovery equipment;

[0169] The medium-equipment matching constraint of the cascade utilization architecture is formed by introducing a binary variable to represent whether the equipment of each grade type can be driven by the residual heat medium of the corresponding grade.

[0170] Optionally, the process of establishing the strategy optimization analysis model comprises:

[0171] A system energy efficiency objective function is constructed with the goal of maximizing the total energy utilization efficiency of the system.

[0172] An energy conversion balance constraint is established to ensure that the total input power of each residual heat medium is equal to the sum of the power utilized by each type of equipment and the power not utilized.

[0173] An equipment operation boundary constraint is established to limit the actual output of each residual heat recovery equipment to not exceed its rated capacity.

[0174] A user load demand constraint is established to ensure that the system output can meet the real-time load demand of the user.

[0175] The system energy efficiency objective function, the medium-equipment matching constraint, the energy conversion balance constraint, the equipment operation boundary constraint, and the user load demand constraint are integrated to construct the strategy optimization analysis model.

[0176] Optionally, the energy conversion balance constraint is:

[0177]

[0178] The equipment operation boundary constraint is:

[0179]

[0180] The user load demand constraint is:

[0181]

[0182] Wherein, F t , S t , and W t are the theoretical residual heat available power of the available flue gas, the available steam, and the available hot water at time t, respectively. t out , S t out , and W t outrespectively, are the unused heat power of available flue gas, available steam and available hot water at time t, Q i in,t is the waste heat power of flue gas utilized by i equipment at time t, i includes flue gas type organic Rankine cycle generator set, flue gas type absorption heat pump, flue gas type absorption refrigerator, waste heat recovery boiler and flue gas-water heat exchanger, Q j in,t is the waste heat power of steam utilized by j equipment at time t, j includes steam type organic Rankine cycle generator set, steam type absorption heat pump, steam type absorption refrigerator and steam-water heat exchanger, Q k in,t is the waste heat power of hot water utilized by k equipment at time t, k includes hot water type organic Rankine cycle power generation equipment, hot water type absorption heat pump, hot water type absorption refrigerator, S WBOI t is the steam heat power output by waste heat recovery boiler at time t, W t HEX_F is the hot water heat power output by flue gas-water heat exchanger at time t, W t HEX_S is the hot water heat power output by steam-water heat exchanger at time t, l is power generation equipment including flue gas type, steam type and hot water type organic Rankine cycle generator set, m is heating equipment including flue gas type, steam type, hot water type absorption heat pump and compression heat pump, n is refrigeration equipment including flue gas type, steam type, hot water type absorption refrigerator and compression refrigerator, E t l is the power generation power of power generation equipment at time t, H t m is the heating power of heating equipment at time t, C t n is the refrigeration power of refrigeration equipment at time t, P l , P m , P n respectively, are the rated capacity values of each power generation equipment, heating equipment and refrigeration equipment, E t d is the user electricity demand power at time t, E t HP , E t CC respectively, are the power consumption of compression heat pump and compression refrigerator at time t, H t d is the user heat demand power at time t, C t d is the user cold demand power at time t.

[0183] The waste heat recovery strategy analysis device provided by the embodiment of the application can be applied to a waste heat recovery strategy analysis equipment. Figure 3A hardware structure block diagram of the waste heat recovery strategy analysis device is shown with reference to Figure 3 The hardware structure of the waste heat recovery strategy analysis device can include at least one processor 1, at least one communication interface 2, at least one memory 3, and at least one communication bus 4.

[0184] In the embodiments of the present application, the number of the processor 1, the communication interface 2, the memory 3, and the communication bus 4 is at least one, and the processor 1, the communication interface 2, and the memory 3 complete communication with each other through the communication bus 4.

[0185] The processor 1 can be a central processing unit CPU, or an application specific integrated circuit ASIC, or one or more integrated circuits configured to implement the embodiments of the present application, etc.

[0186] The memory 3 can include a high-speed RAM memory, and can also include a non-volatile memory, etc., such as at least one disk memory.

[0187] The memory stores a program, and the processor can call the program stored in the memory, and the program is used to:

[0188] Flow rate and inlet temperature parameters of each waste heat medium are acquired respectively, and based on preset environmental parameters and discharge temperature limits, theoretical waste heat recovery powers of each waste heat medium are calculated by a theoretical waste heat recovery calculation formula.

[0189] Based on the theoretical waste heat recovery powers and inherent performance parameters of each waste heat recovery device, an energy conversion model between energy input and output of each waste heat recovery device is established.

[0190] A cascade utilization architecture is constructed according to the grade of the waste heat medium, to constrain the allocation path and available device set of the waste heat medium of different grades, and the allocation rule of the cascade utilization architecture is determined as a medium device matching constraint, wherein the high-grade waste heat medium is preferentially allocated to a high-grade energy conversion device.

[0191] Based on the cascade utilization architecture, the energy conversion model, and the theoretical waste heat recovery amount, a strategy optimization analysis model including the medium device matching constraint, an energy conversion balance constraint, a device operation boundary constraint, and a user load demand constraint is established with the goal of maximizing the overall energy utilization efficiency of the system, and is solved to obtain a waste heat recovery strategy including optimal device configuration and operation mode. Optionally, the refinement function and the expansion function of the program can refer to the description above.

[0192] The embodiment of the present application also provides a readable storage medium which can store a program suitable for processor execution, and the program is used for:

[0193] Flow and inlet temperature parameters of each residual heat medium are acquired respectively, and based on preset environmental parameters and discharge temperature limits, theoretical residual heat recovery powers of each residual heat medium are calculated by a theoretical residual heat recovery calculation formula;

[0194] Based on the theoretical residual heat recovery powers and inherent performance parameters of each residual heat recovery device, an energy conversion model between energy inputs and outputs of each residual heat recovery device is established;

[0195] A cascade utilization architecture is constructed according to the grade of the residual heat medium, so as to constrain the distribution path and available device set of the residual heat medium with different grades, and the distribution rule of the cascade utilization architecture is determined as a medium-device matching constraint, wherein the high-grade residual heat medium is preferentially distributed to a high-grade energy conversion device;

[0196] Based on the cascade utilization architecture, the energy conversion model and the theoretical residual heat recovery amount, a strategy optimization analysis model containing the medium-device matching constraint, an energy conversion balance constraint, a device operation boundary constraint and a user load demand constraint is established with the maximum overall energy utilization efficiency of the system as a target, and is solved to obtain a residual heat recovery strategy containing optimal device configuration and operation mode. Optionally, the refinement function and the expansion function of the program can refer to the description above.

[0197] The embodiment of the present application also provides a computer program product comprising a computer program, which, when executed by a processor, performs the method.

[0198] Flow and inlet temperature parameters of each residual heat medium are acquired respectively, and based on preset environmental parameters and discharge temperature limits, theoretical residual heat recovery powers of each residual heat medium are calculated by a theoretical residual heat recovery calculation formula;

[0199] Based on the theoretical residual heat recovery powers and inherent performance parameters of each residual heat recovery device, an energy conversion model between energy inputs and outputs of each residual heat recovery device is established;

[0200] A cascade utilization architecture is constructed according to the grade of the residual heat medium, so as to constrain the distribution path and available device set of the residual heat medium with different grades, and the distribution rule of the cascade utilization architecture is determined as a medium-device matching constraint, wherein the high-grade residual heat medium is preferentially distributed to a high-grade energy conversion device;

[0201] Based on the cascade utilization architecture, the energy conversion model and the theoretical waste heat recovery amount, a strategy optimization analysis model is established with the objective of maximizing the overall energy utilization efficiency of the system, and the model is solved to obtain a waste heat recovery strategy including optimal device configuration and operation mode. Optionally, the refinement and expansion functions of the program can refer to the description above.

[0202] Finally, it should be noted that the terms such as first and second are used herein merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between such entities or operations. Moreover, the terms "comprising", "including", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements recited, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by an indefinite article "a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0203] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be mutually referred to.

[0204] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A waste heat recovery strategy analysis method, characterized in that, include: The flow rate and inlet temperature parameters of each waste heat medium are obtained respectively. Based on the preset environmental parameters and discharge temperature limit, the theoretical waste heat recovery power of each waste heat medium is calculated hourly using the theoretical waste heat recovery calculation formula. Based on the theoretical waste heat recovery power and the inherent performance parameters of each waste heat recovery device, an energy conversion model between the energy input and output of each waste heat recovery device is established. A tiered utilization architecture is constructed based on the grade of the waste heat medium to constrain the distribution path and available equipment set of the waste heat medium of different grades. The distribution rules of the tiered utilization architecture are determined as medium-equipment matching constraints, wherein high-grade waste heat medium is preferentially allocated to high-grade energy conversion equipment. Based on the cascade utilization architecture, the energy conversion model, and the theoretical waste heat recovery amount, with the goal of maximizing the overall energy utilization efficiency of the system, a strategy optimization analysis model is established, which includes the constraints of medium equipment matching, energy conversion balance, equipment operation boundary, and user load demand. The model is then solved to obtain a waste heat recovery strategy that includes the optimal equipment configuration and operation mode.

2. The method according to claim 1, characterized in that, The waste heat medium includes at least steam, flue gas, and hot water; The theoretical formula for calculating the waste heat recovery of the steam is as follows: The theoretical formula for calculating the waste heat recovery of the flue gas is as follows: The theoretical formula for calculating the waste heat recovery of the hot water is: Among them, S t Let m be the theoretical waste heat recovery amount of steam during time period t. t st h is the mass flow rate of steam during time period t. t in Let h be the vapor enthalpy before the temperature and pressure change at time t. t amb Let F be the specific enthalpy of steam at time t under standard conditions. t v represents the theoretical waste heat recovery of the flue gas during time period t. t f Let c be the volumetric flow rate of the flue gas during time period t. f c' is the average volumetric isobaric heat capacity at the flue gas supply temperature. f T is the average volumetric isobaric heat capacity at the flue gas discharge temperature. t in Let T be the initial temperature of the flue gas during time period t. out W is the specified flue gas exhaust temperature. t Let m be the theoretical waste heat recovery amount of hot water during time period t. t w Let c be the mass flow rate of hot water during time period t. w T is the specific heat at constant pressure of a thermal fluid. t in Let T be the inlet temperature of the hot water during time period t. amb The set ambient temperature.

3. The method according to claim 1, characterized in that, The waste heat recovery equipment includes at least an organic Rankine cycle generator set, an absorption heat pump, an absorption chiller, a waste heat recovery boiler, a heat exchanger, a compression heat pump, and a compression chiller. The energy conversion model of the organic Rankine cycle generator set is as follows: The energy conversion model of the absorption heat pump is as follows: The energy conversion model of the absorption chiller is as follows: The energy conversion model of the waste heat recovery boiler is as follows: The energy conversion model of the heat exchanger is as follows: The energy conversion model for the compression heat pump and compression refrigerator is as follows: Among them, E t ORC Q represents the net output power of the organic Rankine cycle generator set during time period t. in,t ORC η is the equivalent heat power absorbed by the organic Rankine cycle from the waste heat source during time period t. heat For the organic Rankine cycle thermal efficiency, η rev For the heat recovery efficiency of the evaporator, H t AHP Q is the heating power of the absorption heat pump during time period t. in,t AHP C represents the equivalent heat power absorbed by the absorption heat pump from the waste heat source during time period t. t AbC Q is the cooling capacity of the absorption chiller during time period t. in,t AbC Let t be the equivalent heat power absorbed by the absorption chiller from the waste heat source during time period t, and COP be the heating performance coefficient of the absorption heat pump or the cooling performance coefficient of the absorption chiller. t WBOI F' is the equivalent thermal power of the steam produced by the waste heat recovery boiler during time period t. t WBOI η is the equivalent thermal power of the flue gas input during time period t. WBOI For the conversion efficiency of waste heat recovery boilers, W' t HEX_F F' is the equivalent thermal power of the hot water produced by the flue gas-water heat exchanger during time period t. t HEX_F η is the equivalent thermal power of the flue gas input during time period t. HEX_F For the conversion efficiency of the flue gas-water heat exchanger, W' t HEX_S S' is the equivalent thermal power of the hot water produced by the steam-water heat exchanger during time period t. t HEX_F η is the equivalent thermal power of the steam input during time period t. HEX_S For the conversion efficiency of a steam-water heat exchanger, H t HP E represents the heating power of the compression heat pump during time period t. t HP For the electrical power consumed by the compression heat pump during time period t, COP HP C is the coefficient of performance for a compression heat pump. t CC E represents the refrigeration capacity of the compressor chiller during time period t. t CC For the electrical power consumed by the compressor chiller during time period t, EER CC The coefficient of performance (COP) of a compression refrigeration machine.

4. The method according to claim 1, characterized in that, A tiered utilization architecture is constructed based on the grade of the waste heat medium to constrain the distribution paths and available equipment sets for waste heat media of different grades. The distribution rules of the tiered utilization architecture are determined as medium-equipment matching constraints, including: The waste heat medium is classified into high-grade waste heat medium, medium-grade waste heat medium, and low-grade waste heat medium according to its temperature level. Based on the grade, the allocation priority of the waste heat medium and the matching rules of the available equipment types are set. High-grade waste heat medium drives all types of waste heat recovery equipment, medium-grade waste heat medium drives medium-grade and low-grade waste heat recovery equipment, and low-grade waste heat medium only drives low-grade waste heat recovery equipment. By introducing binary variables to characterize whether equipment of each grade can be driven by the corresponding grade of waste heat medium, the medium equipment matching constraint of the cascade utilization architecture is formed.

5. The method according to claim 1, characterized in that, The process of establishing the strategy optimization analysis model includes: With the goal of maximizing the total energy utilization efficiency of the system, a system energy efficiency objective function is constructed. Establish energy conversion balance constraints to ensure that the total input power of each waste heat medium is equal to the sum of the power utilized by various types of equipment and the unutilized power; Establish equipment operation boundary constraints to limit the actual output of each waste heat recovery device from exceeding its rated capacity; Establish user load demand constraints to ensure that the system output can meet the real-time load demands of users; The strategy optimization analysis model is constructed by integrating the system energy efficiency objective function, the medium equipment matching constraints, the energy conversion balance constraints, the equipment operation boundary constraints, and the user load demand constraints.

6. The method according to claim 1 or 5, characterized in that, The energy conversion balance constraint is: The equipment operation boundary constraints are as follows: The user load demand constraint is as follows: Among them, F t S t W t F represents the theoretical waste heat power available at time t, consisting of available flue gas, available steam, and available hot water. t out S t out W t out Q represents the unutilized thermal power of available flue gas, available steam, and available hot water at time t. i in,t For time t, the equipment utilizes the waste heat power from the flue gas, including a flue gas-type organic Rankine cycle generator set, a flue gas-type absorption heat pump, a flue gas-type absorption chiller, a waste heat recovery boiler, and a flue gas-water heat exchanger. j in,t For time t, equipment j utilizes waste heat power from steam, including a steam-type organic Rankine cycle generator set, a steam-type absorption heat pump, a steam-type absorption chiller, and a steam-water heat exchanger. Q k in,t Let k be the power generated by the waste heat in the hot water at time t. k includes a hot water type organic Rankine cycle power generation unit, a hot water type absorption heat pump, and a hot water type absorption chiller. S WBOI t Let W be the steam thermal power produced by the waste heat recovery boiler at time t. t HEX_F Let W be the heat power of the hot water produced by the flue gas-water heat exchanger at time t. t HEX_S Let t be the thermal power of the hot water produced by the steam-water heat exchanger; l be the power generation equipment including flue gas type, steam type, and hot water type organic Rankine cycle generator sets; m be the heating equipment including flue gas type, steam type, hot water type absorption heat pumps, and compression heat pumps; n be the refrigeration equipment including flue gas type, steam type, hot water type absorption chillers, and compression chillers; E t l H represents the power output of the power generation equipment at time t. t m Let C be the heating power of the heating equipment at time t. t n Let P be the cooling power of the refrigeration equipment at time t. l P m P n These are the rated capacity values ​​for each power generation device, heating device, and refrigeration device, E. t d Let E be the power demand of the user at time t. t HP E t CC H represents the power consumption of the compression heat pump and the compression chiller at time t, respectively. t d Let C be the user's thermal power demand at time t. t d Let t be the power required by the user for cooling.

7. A waste heat recovery strategy analysis device, characterized in that, include: The theoretical recovery calculation module is used to obtain the flow rate and inlet temperature parameters of each waste heat medium, and based on the preset environmental parameters and discharge temperature limit, calculate the theoretical waste heat recovery power of each waste heat medium hourly using the theoretical waste heat recovery calculation formula. The energy conversion establishment module is used to establish an energy conversion model between the energy input and output of each waste heat recovery device based on the theoretical waste heat recovery power and the inherent performance parameters of each waste heat recovery device. The gradient architecture allocation module is used to construct a tiered utilization architecture based on the grade of the waste heat medium to constrain the allocation path and available equipment set of the waste heat medium of different grades, and to determine the allocation rules of the tiered utilization architecture as the medium-equipment matching constraint, wherein high-grade waste heat medium is preferentially allocated to high-grade energy conversion equipment. The waste heat recovery strategy analysis module is used to establish a strategy optimization analysis model based on the cascade utilization architecture, the energy conversion model, and the theoretical waste heat recovery amount, with the goal of maximizing the overall energy utilization efficiency of the system. This model includes constraints on the matching of media equipment, energy conversion balance, equipment operation boundary, and user load demand. The model is then solved to obtain a waste heat recovery strategy that includes the optimal equipment configuration and operation mode.

8. A waste heat recovery strategy analysis device, characterized in that, Including memory and processor; The memory is used to store programs; The processor is used to execute the program to implement each step of the waste heat recovery strategy analysis method as described in any one of claims 1-6.

9. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements each step of the waste heat recovery strategy analysis method as described in any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, The computer program is executed by the processor to perform the steps of the waste heat recovery strategy analysis method as described in any one of claims 1-6.

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