An intensive design method for a nuclear island cold chain system group based on an optimization algorithm

Abstract

The present invention provides an intensive design method for a nuclear island cold chain system group based on an optimization algorithm, comprising the following steps: Step 1: Establish an atmospheric and seawater climate parameter model according to the selected power plant site; Step 2: Determine the heat sources and their heat loads inside the plant building, and construct an internal space heat release model of the plant building in combination with the internal volume of the plant building rooms; Step 3: Determine the relationships between the various systems and equipment in the nuclear power plant cold chain system, and conduct a check according to the operating conditions of the cold chain system; Step 4: Calculate the guiding parameters for design and operation in the plan; Step 5: Optimize the plan through the optimization algorithm, and obtain the plan details and evaluation indicators of the optimal plan. The present invention uses the investment cost during the construction of the nuclear power plant and the annual power consumption during the operation process as the evaluation guidelines, comprehensively considers the design plan and operation plan of the cold chain system during the optimization process, avoids the situation of attending to one thing and losing sight of another in the plan, and improves the reliability of the method.

Description

Technical Field

[0001] The present invention relates to the technical field of intensive design of nuclear island cold chain related system groups, and particularly to an intensive design method for nuclear island cold chain system groups based on an optimization algorithm. Background Art

[0002] The cold chain system refers to a series of systems that export the heat generated by reactors and equipment not used for power generation to the atmosphere or seawater under normal operation and accident conditions of nuclear power plants, mainly including ventilation systems, chilled water systems, equipment cooling water systems, and important service water systems, etc. The capacity design of these cold chain systems plays a crucial role in the safety and economy of power plants.

[0003] Due to the large scale of the current cold chain system design and the numerous specialties and systems involved, there are many factors to be considered during the design process. To ensure sufficient design capacity, the margins of systems and equipment need to be considered overall and iterative calculations need to be carried out repeatedly in actual design. At the same time, the cold chain systems of general nuclear power plants mainly rely on the design experience of designers during design, and the design and selection parameters of equipment are selected based on extreme operating conditions of the maximum envelope. The overall design margin of the system is large, and some equipment operates under conditions with a load lower than 30% of the design load for a long time during actual operation. Therefore, although the design of the cold chain system of the nuclear power plant meets the requirements of performance and safety, it does not form an optimal design plan that takes all factors into consideration, increases the construction cost and operation and maintenance costs of the nuclear power plant, weakens the economy of the nuclear power plant, and also affects the safe operation of equipment. Summary of the Invention

[0004] The purpose of the present invention is to provide an intensive design method for nuclear island cold chain system groups based on an optimization algorithm, which solves the technical problem of reducing unnecessary design margins during the design process of cold chain systems.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] An intensive design method for nuclear island cold chain system groups based on an optimization algorithm, comprising the following steps:

[0007] Step 1: Establish an atmospheric and seawater climate parameter model according to the selected power plant site;

[0008] Step 2: Determine the heat sources and their heat loads in the plant building, and construct an internal space heat release model of the plant building in combination with the internal volume of the plant building rooms;

[0009] Step 3: Determine the relationships between the systems and equipment in the nuclear power plant cold chain system, and check according to the operating conditions of the cold chain system;

[0010] Step 4: Calculate the guiding parameters for design and operation in the scheme;

[0011] Step 5: Optimize the solution through an optimization algorithm and obtain the solution details and evaluation indicators of the optimal solution.

[0012] Step 1 includes:

[0013] Step 1.1: Determine the latitude and latitude range where the nuclear power plant site is located;

[0014] Step 1.2: Determine the daily variations of the atmospheric temperature, atmospheric relative humidity, and seawater temperature at the nuclear power plant location based on the latitude range, and obtain the corresponding numerical data for each parameter to form data sample base points;

[0015] Step 1.3: Fit the data obtained in Step 1.2 to obtain the annual variation curves of the atmospheric temperature, atmospheric relative humidity, and seawater temperature;

[0016] Step 1.4: Based on the annual variation curves in Step 1.3, construct a curve fitting formula, calculate the daily atmospheric and seawater climate parameters according to requirements, and form an atmospheric and seawater climate parameter model;

[0017] In Step 1.3, use the least squares method to fit the sample base points of the atmospheric and seawater climate parameters obtained to obtain the annual variation curves of the atmospheric temperature, atmospheric relative humidity, and seawater temperature.

[0018] In Step 1.4, the atmospheric and seawater climate parameter model is:

[0019] where T is the atmospheric or seawater climate parameter function, a0 and a i are the undetermined coefficients for fitting, t i is the atmospheric or seawater sample parameter for that month, and i is the month.

[0020] Step 2 includes:

[0021] Step 2.1: Determine the equipment, systems, and cables that dissipate heat into the air in different rooms of different buildings, and clarify the heat load;

[0022] Step 2.2: Customize and input the internal volumes of the relevant buildings and rooms;

[0023] Step 2.3: Construct a heat release model for the internal space of the building.

[0024] In Step 2, the heat release model for the internal space of the building is:

[0025] ∑Q h +c·L p ·ρ n ·tn=∑Q f ·c·L jj ·ρ jj ·tjj +c·L zj ·ρ w ·t w +c·L xh ·ρ n ·(t s -t n ),

[0026] Among them, Q h is the total heat loss of the enclosure structure and materials for heat absorption, Q f is the total heat release of production equipment, products and heating and cooling equipment, L p is the local and overall exhaust air volume, L jj is the mechanical inlet air volume, L zj is the natural inlet air volume, L xh is the recirculating air volume, ρ n is the indoor air density, ρ w is the outdoor air density, ρ jj is the mechanical inlet air density, t n is the temperature of the indoor exhaust air, t w is the calculated outdoor air temperature, t jj is the mechanical inlet air temperature, t s is the recirculating supply air temperature.

[0027] Step 3 includes:

[0028] Step 3.1: Determine the logical relationship of the heat load between the nuclear power plant cold chain systems;

[0029] Step 3.2: Determine the main heat exchange equipment and fluid power equipment of the cold chain system;

[0030] Step 3.3: Determine the main input parameters of the equipment that needs to be designed or selected in Step 3.2;

[0031] Step 3.4: According to the actual requirements during the preliminary design of the nuclear power plant cold chain system, customize and add or subtract equipment, specify the equipment type and the number of equipment, customize and combine the equipment and form a pipe network structure to obtain the preliminary design result of the equipment;

[0032] Step 3.5: According to the actual requirements during the preliminary design of the nuclear power plant cold chain system and a series of parameters input in Step 3.4, customize the operating conditions corresponding to different operating conditions of the cold chain system in the nuclear power plant.

[0033] In Step 3.1, the nuclear power plant cold chain system includes: ventilation system, refrigeration system, equipment cooling water system, spent fuel pool and refueling system, residual heat removal system, important service water system.

[0034] In Step 3.1, the logical relationship of the heat load among the cold chain systems in the nuclear power plant is as follows: The ventilation system transfers the heat load to the refrigeration system, and the refrigeration system, spent fuel pool and refueling system, and residual heat removal system transfer the heat load to the component cooling water system, which then transfers the heat load to the essential service water system.

[0035] In Step 3.2, the main heat exchange equipment and fluid dynamic equipment include: plate heat exchangers, shell and tube heat exchangers, cooling coils, fans, chilled water pumps, component cooling water pumps, essential service water pumps, and the mechanical heat exchange part of the primary coolant pump.

[0036] Step 3.3 includes:

[0037] Step 3.3.1: The design flow rate G of each device under the design conditions of the cold chain system in the nuclear power plant;

[0038] Step 3.3.2: The heat load Q of each device in the actual project,

[0039] Q = G i CpΔT,

[0040] where G i is the flow rate, Cp is the specific heat capacity, and ΔT is the temperature difference between the inlet and outlet;

[0041] Step 3.3.3: The design temperature T of each device under the design conditions of the cold chain system in the nuclear power plant D ;

[0042] Step 3.4 includes:

[0043] Step 3.4.1: Select the cold chain system to be used to build a model, or create a new blank model, and add or delete several devices and their pipelines in the module;

[0044] Step 3.4.2: Specify the types and numbers of devices;

[0045] Step 3.4.3: Input the design parameters of the devices according to the requirements of the designers;

[0046] Step 3.4.4: Specify the number of loops of the component cooling water system, and accordingly change the number of essential service water systems. Then, connect the designed devices to the corresponding systems according to the requirements of the designers to form a system layout combination, and specify the loops where the devices in the component cooling water system are located to form a pipeline network structure;

[0047] Step 3.4.5: Specify the lengths of the pipelines and the numbers of pipeline components in the pipeline network according to the parameters, ownership relationships, and pipeline network structures of the systems and devices in Step 3.4.4.

[0048] In Step 3.4, the selection of equipment types includes: customizing the fan type as a DC fan or an axial flow fan; customizing the refrigeration unit type as a variable frequency chiller or a fixed frequency chiller; customizing the heat exchanger type as a plate heat exchanger, a shell and tube heat exchanger, or a cooling coil; customizing the pump type as a fixed frequency pump or a variable frequency pump.

[0049] Step 3.5 includes:

[0050] Step 3.5.1: Determine the commissioning status of the equipment and the system under the customized operating conditions, obtain their flow rates and heat loads, and compare and select the maximum flow rate and heat load of each equipment and system.

[0051] Q max = Max(Q i ),

[0052] G max = Max(G i ),

[0053] where Q max is the maximum heat load selected, Q i is the heat load of each equipment and system, G max is the maximum flow rate selected, and G i is the flow rate of each equipment and system;

[0054] Step 3.5.2: According to the maximum flow rate requirements of each equipment under different operating conditions in Step 3.5.1 and the layout combination mode of each equipment in Step 3.4.4, select the most economical pipeline diameter D N through the most economical flow velocity range, and specify the pipeline length according to the actual requirements during the initial design of the cold chain system;

[0055] Step 3.5.3: According to the maximum flow rate under different operating conditions, the equipment design results and the pipe network structure obtained in Step 3.4, and the pipeline dimensions in Step 3.5.2, obtain the design and selection results of the fans and pumps for the ventilation system, refrigeration system, equipment cooling water system, and important plant water system;

[0056] Step 3.5.4: According to the initial design results of the equipment in Step 3.4, combined with the various operating condition parameters customized in Step 3.5, check the equipment and the system.

[0057] Step 4 includes:

[0058] Step 4.1: Calculate the overall design investment cost C total of the cold chain system;

[0059] Step 4.2: Calculate the annual total power consumption Q E of the cold chain system under each operating condition.

[0060] In Step 4.1, the overall design investment cost of the cold chain system is:

[0061] C total = C Ep + C Pipe + C Room + C Up ,

[0062] where C Ep is the equipment purchase and installation cost, C Pipe is the pipeline network purchase and installation cost, C Room is the composition of the plant construction cost, and C Up is the operation and maintenance cost during the life of the nuclear power plant.

[0063] In Step 4.2, the annual total power consumption is:

[0064] Q E = 365 × 24 × 3600 × (P F + P C + P p ),

[0065] where P F is the fan power, P C is the refrigeration unit power, and P P is the pump power.

[0066] Step 5 includes:

[0067] Step 5.1: Form corresponding optimization variables according to the custom design parameters of the system and equipment in Step 3, use the numerical values of the design parameters input in Step 3 as the original values of the corresponding optimization variables, and form the upper limit value and lower limit value of the optimization variables.

[0068]

[0069] where x up is the upper limit value of the optimization variable, x low is the lower limit value of the optimization variable, x is the original value of the optimization variable, a is the upper limit multiple of the optimization variable, and b is the lower limit multiple of the optimization variable;

[0070] Step 5.2: Form the value range of each optimization variable according to the upper and lower limit values of the optimization variables obtained in Step 5.1, and randomly generate the value of each optimization variable within the value range of each optimization variable in the way of generating random numbers. Replace the original design parameter value with the newly generated optimization variable value and use it as the initial design parameter of the system and equipment in the optimal design;

[0071] Step 5.3: According to the overall design investment cost C of the cold chain system calculated in Step 4 totalThe total annual power consumption Q of the cold chain system under various operating conditions E To optimize the target, while reducing C total With Q E The numerical value of is used as the optimization direction to achieve the purpose of optimizing the overall design investment cost of the cold chain system and the annual total power consumption of the cold chain system under various operating conditions;

[0072] Step 5.4: According to the optimization variables obtained in step 5.2 and the optimization target obtained in step 5.3, iterative calculations of the optimization design are repeatedly performed. In each optimization design, the optimization variable values ​​and optimization target values ​​of the corresponding optimization design are output, and an optimization plan is formed according to the actual physical meaning represented.

[0073] Compared with the prior art, the nuclear island cold chain system cluster centralized design method based on optimization algorithm provided by the present invention has the following beneficial effects:

[0074] During the design process, the present invention designs the cold chain system of a nuclear power plant in a customized manner, reasonably reduces unnecessary design margins, uses optimization algorithms to perform overall optimization of the cold chain system of a nuclear power plant, and scientifically and efficiently designs and evaluates the cold chain system of a nuclear power plant.

[0075] The present invention uses the investment cost during construction of a nuclear power plant and the annual power consumption during operation as evaluation guidelines, and comprehensively considers the design and operation plans of the cold chain system during the optimization process, thereby avoiding the situation of losing sight of one thing while focusing on another in the plan, and improving the reliability of the method.

[0076] The present invention can adapt to the design requirements of the cold chain systems of various nuclear power plants within a reasonable range, accurately analyze and calculate the capacity of the entire cold chain system, reduce excessive redundancy in the original design process, improve design work efficiency, greatly reduce system design deviations caused by insufficient experience of designers, and improve the safety of nuclear power plants. At the same time, the operating plan of the cold chain system is provided with improvement directions through atmospheric and seawater climate parameters, thereby reducing the investment and operating costs of nuclear power plants.

[0077] Furthermore, the present invention utilizes a high-degree-of-freedom customization method to combine atmospheric and seawater climate parameter models, plant internal space heat release models, equipment and system design models, and system operating condition models. The safety requirements of each system are used as engineering design constraints, and an optimization algorithm is used to optimize the overall design and operation plan of the cold chain system. The investment cost during the construction of the nuclear power plant and the annual power consumption during operation are used as evaluation guidelines to derive the optimal design and operation plan for the nuclear power plant cold chain system.

[0078] Furthermore, the atmospheric and seawater climate parameter model provided by the present invention provides a method that, based on the geographical location of the nuclear power plant construction site, makes full use of the climate parameter reference points of the atmosphere and seawater in the recent 5 years, and through a high-precision mathematical fitting method, while ensuring that the fitting error is not higher than 10 -3 , obtains the curves of atmospheric temperature, atmospheric relative humidity and seawater temperature changing with time in a year, and can obtain the design reference points according to requirements.

[0079] Furthermore, the internal space heat release model of the plant building provided by the present invention, through the internal volume of the plant building room input by the user, uses the air space heat model with internal heat sources to simulate the internal heat release model of the actual plant building room to meet the heat load transfer requirements. Description of the Drawings

[0080] Figure 1 It is a schematic flow chart of the intensive design method of the nuclear island cold chain system group based on the optimization algorithm provided by the embodiment of the present invention. Detailed Embodiment

[0081] The following is a further detailed description through specific embodiments.

[0082] As Figure 1 shown, the present invention provides an intensive design method for a nuclear island cold chain system group based on an optimization algorithm. This method is an intensive design method for an atmospheric and seawater climate model, an internal space heat release model of a cold chain system plant building room, a ventilation system, a refrigeration system, an equipment cooling water system, a main user system of equipment cooling water and an important plant service water system. At the same time, this method can be optimized using an optimization algorithm.

[0083] The equipment, systems and cables inside the cold chain system plant building room are the initial heat sources, transferring heat to the air inside the plant building. The heat of the air inside the plant building is led out by the air supply of the ventilation system, and both the fresh air and the recirculated air are cooled by the cooling coils of the ventilation system. The refrigeration system exchanges heat with the ventilation system through the refrigeration unit, and then exchanges heat with the equipment cooling water system through the refrigeration unit. The equipment cooling water system and the important plant service water system exchange heat through the plate heat exchanger of the equipment cooling water system, leading the heat of each user system and equipment into the seawater. Under different operating conditions of the nuclear power plant, the operation status of each equipment and system is also different. The ventilation system needs to adjust the air supply volume according to the change of the safe temperature of each room, the refrigeration system needs to adjust the refrigeration capacity of the refrigeration unit according to the total heat load of the ventilation system, and the equipment cooling water system needs to provide cooling water at a certain temperature according to the flow requirements of each user equipment and subsystem. The mutual influence between each system needs to be considered in the design, and the climate parameters of the atmosphere and seawater need to be considered as a whole to optimize and obtain the optimal cold chain system design and operation plan and evaluation index.

[0084] The present invention takes the investment economy of key equipment of each system and the total annual power consumption of the system as the evaluation guidelines, specifically including the following steps:

[0085] Step 1: Customize and select the construction site of the nuclear power plant, and establish an atmospheric and seawater climate parameter model according to the selected plant site, specifically as follows:

[0086] Step 1.1: Determine the latitude where the nuclear power plant site is located, further determine the latitude range where this dimension is located, and determine the baseline of the temperature change of the atmosphere and seawater;

[0087] Step 1.2: Determine the daily changes of the atmospheric temperature, atmospheric relative humidity and seawater temperature at the location of the nuclear power plant according to the latitude range, and give the sample parameters of the atmospheric temperature, atmospheric humidity and seawater temperature changing with the seasons on a daily basis to form sample base points;

[0088] Step 1.3: Use the least squares method to perform high-precision fitting on the sample base points of the obtained atmospheric and seawater climate parameters, and constrain the fitting error to be no higher than 10 -3 , and obtain the annual change curves of the atmospheric temperature, atmospheric relative humidity and seawater temperature;

[0089] Step 1.4: According to the atmospheric and seawater temperature change curves obtained in Step 1.3, further obtain the curve fitting formula, and then the atmospheric and seawater climate parameters of each day can be calculated according to the requirements to form an atmospheric and seawater climate parameter model. For the finally obtained atmospheric and seawater climate parameter model, the model expression is as follows (the curve fitting formula and the model expression here are the same formula):

[0090]

[0091] where, T is the atmospheric or seawater climate parameter function; a0 and a i are the fitting undetermined coefficients obtained from the linear equations of the sample base points; t i is the atmospheric or seawater sample parameter of this month, with the unit of °C; i is the month.

[0092] Step 2: Determine the heat sources in the plant and their heat load amounts, and combine the internal volume of the plant rooms to input the plant heat source parameters in a customized manner to construct an internal space heat release model of the plant, specifically as follows:

[0093] Step 2.1: Determine the equipment, systems, and cables that dissipate heat to the air in different rooms of different plants, and clarify their heat load amounts Q f ;

[0094] Step 2.2: Customize and input the internal volumes of each relevant plant and room;

[0095] Step 2.3: Construct an internal space heat release model of the plant, and the model expression is as follows:

[0096] ∑Q h + c·L p ·ρ n ·t n =∑Q f ·c·L jj ·ρ jj ·t jj + c·L zj ·ρ w ·t w + c·L xh ·ρ n ·(t s - t n )

[0097] Among them, Q h is the total heat loss of the enclosure structure and materials for heat absorption, with the unit of kW; Q f is the total heat release of production equipment, products and heating and cooling equipment, with the unit of kW; L p is the local and overall exhaust air volume, with the unit of m 3 / s; L jj is the mechanical intake air volume, with the unit of m 3 / s; L zj is the natural intake air volume, with the unit of m 3 / s; L xh is the recirculating air volume, with the unit of m 3 / s; ρ n is the indoor air density, with the unit of kg / m 3 ; ρ w is the outdoor air density, with the unit of kg / m 3 ; ρ jj is the mechanical intake air density, with the unit of kg / m 3 ; t n is the indoor exhaust air temperature, with the unit of °C; t w is the outdoor air calculated temperature, with the unit of °C; t jj is the mechanical intake air temperature, with the unit of °C; t s is the recirculating supply air temperature, with the unit of °C.

[0098] Step 3: Determine the relationships between the systems and equipment in the nuclear power plant cold chain system, design or select the equipment and systems, and check according to the operating conditions of the cold chain system, specifically as follows:

[0099] Step 3.1: Determine the heat load logical relationship among the cold chain systems in the nuclear power plant. The key systems in the cold chain system of the nuclear power plant in this embodiment include: ventilation system, refrigeration system, equipment cooling water system, spent fuel pool and refueling system, residual heat removal system, and essential service water system. The heat load logical relationship among the systems in this example is as follows: The ventilation system transfers the heat load to the refrigeration system, and the refrigeration system, spent fuel pool and refueling system, and residual heat removal system transfer the heat load to the equipment cooling water system, and the equipment cooling water system transfers the heat load to the essential service water system;

[0100] Step 3.2: Determine the main heat exchange equipment and fluid power equipment of the cold chain system. The key equipment in this embodiment includes plate heat exchangers, shell-and-tube heat exchangers, cooling coils, fans, chilled water pumps, equipment cooling water pumps, essential service water pumps, the mechanical heat exchange part of the primary coolant pump, etc., and heat exchangers for user equipment of the equipment cooling water system among the key system equipment;

[0101] Step 3.3: Determine the main input parameters of the equipment that need to be designed or selected in Step 3.2, including the following:

[0102] Step 3.3.1: The design flow rate G of each equipment under the design conditions of the cold chain system in the nuclear power plant;

[0103] Step 3.3.2: The heat load Q of each equipment in the actual project is as follows:

[0104] Q = G i CpΔT

[0105] where G i is the flow rate, with the unit of kg / h; Cp is the specific heat capacity, with the unit of J / kg / °C; ΔT is the temperature difference between the inlet and outlet, with the unit of °C.

[0106] Step 3.3.3: The design temperature T of each equipment under the design conditions of the cold chain system in the nuclear power plant D ;

[0107] Step 3.4: According to the actual requirements during the preliminary design of the cold chain system in the nuclear power plant, customarily add or delete equipment, specify the equipment type and the number of equipment, customarily combine the equipment and form a pipe network structure to obtain the preliminary design result of the equipment. The specific custom functions include the following:

[0108] Step 3.4.1: First, select the cold chain system model you want to use to build a model. For example, select the default "Hualong" cold chain system model or create a new blank model. Based on the selected model, add or delete several equipment and the pipes they are located in the module;

[0109] Step 3.4.2: Secondly, specify the equipment types and the number of equipment. The selection of equipment types mainly includes the following: customize the fan type as a DC fan or an axial flow fan; customize the refrigeration unit type as a variable frequency chiller or a fixed frequency chiller; customize the heat exchanger type as a plate heat exchanger, a shell and tube heat exchanger or a cooling coil; customize the pump type as a fixed frequency pump or a variable frequency pump.

[0110] Step 3.4.3: Then, according to the needs of the designers, input the design parameters of the equipment. The designers can either select the default parameters or input new parameters. These parameters can be used for the design of the cold chain system, and also for the verification and operation evaluation in the subsequent steps. They can also be used as the boundary parameters for design and operation optimization.

[0111] Step 3.4.4: Next, it is necessary to specify the number of loops of the equipment cooling water system, and accordingly change the number of important plant water systems. Then, according to the needs of the designers, connect the designed equipment to the corresponding system to form the layout combination of the system, and specify the loop where the equipment in the equipment cooling water system is located to form the pipe network structure.

[0112] Step 3.4.5: According to the parameters, ownership relationship and pipe network structure of the system and equipment in Step 3.4.4, specify the pipe length and the number of pipe components (such as valves, elbows) in the pipe network.

[0113] Step 3.5: According to the actual needs during the preliminary design of the nuclear power plant cold chain system and the series of parameters input in Step 3.4, customize the operating conditions corresponding to different operating conditions of the cold chain system in the nuclear power plant as follows:

[0114] Step 3.5.1: Determine the commissioning status of the equipment and the system under the customized operating conditions, obtain their flow rates and heat loads, and compare and select the maximum flow rates and heat loads of each equipment and system.

[0115] Q max =Max(Q i )

[0116] G max =Max(G i )

[0117] Wherein, Q max is the maximum heat load selected by comparison, with the unit of MW; Q i is the heat load of each equipment and system, with the unit of kg / h; G max is the maximum flow rate selected by comparison, with the unit of MW; G i is the flow rate of each equipment and system, with the unit of kg / h.

[0118] Step 3.5.2: According to the maximum flow requirements of each device under different working conditions in Step 3.5.1 and the layout combination of each device in Step 3.4.4, select the most economical pipeline diameter D through the most economical flow velocity range. N And specify the pipeline length according to the actual requirements during the initial design of the cold chain system. Among them, the flow velocity v (m / s) of the water circuit of the cold chain system in the nuclear power plant is: 2.0 ≤ v ≤ 3.8;

[0119] Step 3.5.3: According to the maximum flow under different operating conditions, the equipment design results and pipe network structure obtained in Step 3.4, and the pipeline dimensions in Step 3.5.2, obtain the design and selection results of the fans and pumps for the ventilation system, refrigeration system, equipment cooling water system and important service water system;

[0120] Step 3.5.4: According to the initial design results of the equipment in Step 3.4, combined with the parameters of each operating condition defined in Step 3.5, check the equipment and system.

[0121] In Step 3, determine the equipment design parameters, selection parameters and relevant relationships in a self-defined manner, determine the operating conditions of the cold chain system according to the requirements, and calculate, select and check the key equipment of the cold chain system.

[0122] Step 4: Calculate the guiding parameters for design and operation in the scheme, including the following:

[0123] Step 4.1: Calculate the overall design investment cost C of the cold chain system total . The overall design investment cost of the cold chain system in this embodiment mainly consists of equipment purchase and installation costs, pipe network purchase and installation costs, plant construction costs, and operation and maintenance costs within the life of the nuclear power plant, as follows:

[0124] C total = C Ep + C Pipe + C Room + C Up

[0125] Among them, C Ep is the equipment purchase and installation cost; C Pipe is the pipe network purchase and installation cost; C Room is the plant construction cost; C Up is the operation and maintenance cost within the life of the nuclear power plant.

[0126] Step 4.2: Calculate the annual total power consumption Q of the cold chain system under each operating condition E . The annual total power consumption in this embodiment is the total annual power consumption of the fans, refrigeration units and pumps, as follows:

[0127] Q E= 365×24×3600×(P F + P C + P p )

[0128] where P F is the power of the fan, in W; P C is the power of the refrigeration unit, in W; P P is the power of the water pump, in W.

[0129] Step 5: Optimize the solution through an optimization algorithm and obtain the solution details and evaluation indicators of the optimal solution, specifically including:

[0130] Step 5.1: Form corresponding optimization variables according to the custom design parameters of the system and equipment in Step 3. The physical meaning of the optimization variables is the same as the design parameters that form them. At the same time, use the numerical values of the design parameters input in Step 3 as the original values of the corresponding optimization variables to form the upper and lower limit values of the optimization variables. The calculation method is as follows:

[0131]

[0132] where x up is the upper limit value of the optimization variable, x low is the lower limit value of the optimization variable, x is the original value of the optimization variable and also the value of the design parameter input in Step 3, a is the upper limit multiple of the optimization variable, and b is the lower limit multiple of the optimization variable.

[0133] Step 5.2: Form the value range of each optimization variable according to the upper and lower limit values of the optimization variables obtained in Step 5.1, and randomly generate the values of each optimization variable within the value range of each optimization variable in the way of generating random numbers. Replace the original design parameter values with the newly generated optimization variable values and use them as the initial design parameters of the system and equipment in the optimized design;

[0134] Step 5.3: Use the overall design investment cost C total of the cold chain system calculated in Step 4 and the annual total power consumption Q E of the cold chain system under each operating condition as the optimization objectives. At the same time, take reducing the numerical values of C total and Q E as the optimization direction to achieve the purpose of optimizing the overall design investment cost of the cold chain system and the annual total power consumption of the cold chain system under each operating condition;

[0135] Step 5.4: Based on the optimized variables obtained in Step 5.2 and the optimization objective obtained in Step 5.3, perform iterative calculations for repeated optimization design. In each optimization design, output the optimized variable values and optimization objective values corresponding to the optimized design, form an optimization plan according to their actual physical meanings, and select the top ten plans with a deeper optimization degree based on the optimization degree of the optimization objective for the designers' reference.

[0136] This optimization algorithm is applicable to the high-dimensional optimization problems of multi-variable, multi-objective, and multi-constraint in the cold chain system of nuclear power plants.

[0137] This optimization algorithm can automatically adjust the adaptability of optimized variables and constraint conditions according to the usage of custom functions.

[0138] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An intensive design method for a nuclear island cold chain system group based on an optimization algorithm, characterized in that, It includes the following steps: Step 1: Establish an atmospheric and seawater climate parameter model based on the selected nuclear power plant site; Step 2: Determine the heat sources and their heat loads inside the plant building, and combine with the internal volume of the plant building rooms to construct an internal space heat release model of the plant building; Step 3: Determine the relationships between systems and equipment in the nuclear power plant cold chain system, and check according to the operating conditions of the cold chain system; Step 3 includes: Step 3.1: Determine the heat load logical relationship between cold chain systems in the nuclear power plant; Step 3.2: Determine the main heat exchange equipment and fluid power equipment of the cold chain system; Step 3.3: Determine the main input parameters of the equipment that need to be designed or selected in Step 3.2; Step 3.4: According to the actual needs during the preliminary design of the nuclear power plant cold chain system, customize to add or delete equipment, specify the equipment types and the number of equipment, customize the combination of equipment and form a pipeline network structure to obtain the preliminary design results of the equipment; Step 3.4 includes: Step 3.4.1: Select the cold chain system to be used to build a model, or create a blank model, and add or delete several equipment and their pipelines in the module; Step 3.4.2: Specify the equipment types and the number of equipment; Step 3.4.3: Input the design parameters of the equipment according to the needs of the designers; Step 3.4.4: Specify the number of loops of the equipment cooling water system, and accordingly change the number of important plant water systems, and connect the designed equipment to the corresponding systems according to the needs of the designers to form the layout combination mode of the system, and specify the loops where the equipment in the equipment cooling water system is located to form a pipeline network structure; Step 3.4.5: Specify the pipeline lengths and the number of pipeline components in the pipeline network according to the parameters, ownership relationships and pipeline network structure of the systems and equipment in Step 3.4.4; Step 3.5: According to the actual needs during the preliminary design of the nuclear power plant cold chain system and a series of parameters input in Step 3.4, customize the corresponding operating conditions of the cold chain system under different operating conditions of the nuclear power plant; Step 3.5 includes: Step 3.5.1: Determine the commissioning status of the equipment and systems under the customized operating conditions, obtain their flow rates and heat loads, and compare and select the maximum flow rates and heat loads of each equipment and system; Q max = Max(Q i ) G max = Max(G i ) Among them, Q max is the maximum heat load selected through comparison, and Q i is the heat load of each device and system, and G max is the maximum flow rate selected through comparison, and G i is the flow rate of each device and system; Step 3.5.2: According to the maximum flow rate requirements of each device under different working conditions in Step 3.5.1 and the layout combination of each device in Step 3.4.4, select the most economical pipeline diameter D through the most economical flow velocity range N , and specify the pipeline length according to the actual requirements during the initial design of the cold chain system; Step 3.5.3: According to the maximum flow rates under different operating conditions, the equipment design results and pipeline network structure obtained in Step 3.4, and the pipeline sizes in Step 3.5.2, obtain the design and selection results of the fans and pumps for the ventilation system, refrigeration system, equipment cooling water system and important plant water system; Step 3.5.4: According to the preliminary design results of the equipment in Step 3.4, combined with the customized operating condition parameters in Step 3.5, check the equipment and systems; Step 4: Calculate and obtain the guiding parameters for design and operation in the plan; Step 5: Optimize the plan through an optimization algorithm, and obtain the plan details and evaluation indicators of the optimal plan.

2. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, characterized in that Step 1 includes: Step 1.1: Determine the latitude and latitude range where the nuclear power plant site is located; Step 1.2: Determine the daily changes of the atmospheric temperature, atmospheric relative humidity and seawater temperature at the nuclear power plant location according to the latitude range, and obtain the corresponding numerical data of each parameter to form a data sample base point; Step 1.3: Fit the data obtained in Step 1.2 to obtain the annual variation curves of atmospheric temperature, atmospheric relative humidity, and seawater temperature; Step 1.4: Based on the annual variation curves in Step 1.3, construct a curve fitting formula, and calculate the daily atmospheric and seawater climate parameters according to requirements to form an atmospheric and seawater climate parameter model.

3. The intensive design method of the nuclear island cold chain system group based on the optimization algorithm according to claim 2, characterized in that, In Step 1.3, use the least squares method to fit the sample base points of the obtained atmospheric and seawater climate parameters to obtain the annual variation curves of atmospheric temperature, atmospheric relative humidity, and seawater temperature.

4. The intensive design method of the nuclear island cold chain system group based on the optimization algorithm according to claim 2, characterized in that In Step 1.4, the atmospheric and seawater climate parameter model is as follows: where T is a function of atmospheric or seawater climate parameters, a0 and a i are fitting coefficients to be determined, t i is the atmospheric or seawater sample parameter for that month, and i is the month.

5. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, wherein Step 2 includes: Step 2.1: Determine the equipment, systems, and cables that dissipate heat into the air in different rooms of different workshops, and clarify the heat load quantity; Step 2.2: Customize and input the internal volumes of each relevant workshop and room; Step 2.3: Construct a heat release model for the internal space of the workshop.

6. The intensive design method of the nuclear island cold chain system group based on the optimization algorithm according to claim 5, wherein The heat release model for the internal space of the workshop is: ∑Q h + c·L p · ρ n · t n =∑Q f · c·L jj · ρ jj · t jj + c·L zj · ρ w · t w + c·L xh · ρ n · (t s - t n ), Among them, Q h is the total heat loss of the enclosure structure and material heat absorption, Q f is the total heat release of production equipment, products and heating and cooling equipment, L p is the local and overall exhaust air volume, L jj is the mechanical fresh air volume, L zj is the natural fresh air volume, L xh is the recirculated air volume, ρ n is the indoor air density, ρ w is the outdoor air density, ρ jj is the mechanical fresh air density, t n is the temperature of the indoor exhaust air, t w is the calculated outdoor air temperature, t jj is the mechanical fresh air temperature, t s is the temperature of the recirculated supply air.

7. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, characterized in that In Step 3.1, the nuclear power plant cold chain system includes: a ventilation system, a refrigeration system, an equipment cooling water system, a spent fuel pool and refueling system, a residual heat removal system, and an essential service water system.

8. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 7, characterized in that, In Step 3.1, the heat load logical relationship among the nuclear power plant cold chain systems is: the ventilation system transfers the heat load to the refrigeration system, and the refrigeration system, the spent fuel pool and refueling system, and the residual heat removal system transfer the heat load to the equipment cooling water system, and the equipment cooling water system transfers the heat load to the essential service water system.

9. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, characterized in that, In Step 3.2, the main heat exchange equipment and fluid dynamic equipment include: plate heat exchangers, shell-and-tube heat exchangers, cooling coils, fans, chilled water pumps, equipment cooling water pumps, essential service water pumps, and the mechanical heat exchange part of the primary coolant pump.

10. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, characterized in that, Step 3.3 includes: Step 3.3.1: The design flow rate G of each equipment under the design conditions of the nuclear power plant cold chain system; Step 3.3.2: The heat load quantity Q of each equipment in the actual project, Q = G i CpΔT, where G i is the flow rate, Cp is the specific heat capacity, and ΔT is the temperature difference between the inlet and outlet; Step 3.3.3: Design temperature T of each device under the design conditions of the nuclear power plant cold chain system D。 11. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, characterized in that The selection of equipment types includes: customizing the fan type as a DC fan or an axial flow fan; customizing the refrigeration unit type as a variable frequency chiller or a constant frequency chiller; customizing the heat exchanger type as a plate heat exchanger, a shell-and-tube heat exchanger, or a cooling coil; customizing the pump type as a constant frequency pump or a variable frequency pump.

12. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, characterized in that, Step 4 includes: Step 4.1: Calculate the overall design investment cost C of the cold chain system total ; Step 4.2: Calculate the annual total power consumption Q of the cold chain system under each operating condition E .

13. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 12, wherein In Step 4.1, the overall design investment cost of the cold chain system is: C total = C Ep + C Pipe + C Room + C Up , Among them, C Ep is the equipment purchase and installation cost, C Pipe is the pipeline network purchase and installation cost, C Room is the composition of the factory building construction cost, C Up is the operation and maintenance cost during the life of the nuclear power plant.

14. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 12, characterized in that, In Step 4.2, the total annual power consumption is: Q E = 365 × 24 × 3600 × (P F + P C + P p ), Among them, P F is the fan power, P C is the refrigeration unit power, P P is the water pump power.

15. The intensive design method for the nuclear island cold chain system group based on the optimization algorithm according to claim 1, characterized in that, Step 5 includes: Step 5.1: Form corresponding optimization variables according to the custom design parameters of the systems and equipment in Step 3, use the numerical values of the design parameters input in Step 3 as the original values of the corresponding optimization variables, and form the upper and lower limit values of the optimization variables; where x up is the upper limit value of the optimization variable, x low is the lower limit value of the optimization variable, x is the original value of the optimization variable, a is the upper limit multiple of the optimization variable, and b is the lower limit multiple of the optimization variable; Step 5.2: Form the value range of each optimization variable according to the upper and lower limit values of the optimization variables obtained in Step 5.1, and randomly generate the value of each optimization variable within the value range of each optimization variable in the way of generating random numbers, replace the original design parameter values with the newly generated optimization variable values, and use them as the initial design parameters of the systems and equipment in the optimization design; Step 5.3: Based on the overall design investment cost C of the cold chain system calculated in Step 4 total and the annual total power consumption Q of the cold chain system under each operating condition E as the optimization objectives, and at the same time taking the reduction of the numerical values of C total and Q E as the optimization directions to achieve the purpose of optimizing the overall design investment cost of the cold chain system and the annual total power consumption of the cold chain system under each operating condition; Step 5.4: Based on the optimized variables obtained in Step 5.2 and the optimization objective obtained in Step 5.3, perform iterative calculations for repeated optimization design. In each optimization design, output the optimized variable values and optimization objective values corresponding to the optimization design, and form an optimization plan according to the actual physical meanings they represent.

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