CN105205562A

CN105205562A - Operation optimization method of tower-type solar power station receiver

Info

Publication number: CN105205562A
Application number: CN201510627879.7A
Authority: CN
Inventors: 赵豫红; 盛玲霞
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2015-11-19
Filing date: 2015-11-19
Publication date: 2015-12-30
Anticipated expiration: 2035-11-19
Also published as: CN105205562B

Abstract

The invention discloses a method for optimizing the operation of a tower-type solar power plant receiver. The implementation steps are as follows: (1) Build a distribution parameter model of the tower-type solar power receiver and simulate to obtain that under different light intensities, when the net power generation efficiency of the power plant is the highest, The numerical value of the outlet temperature of the receiver; (2) Design a PID controller, in which the control variable of the controller is the flow rate of the heat transfer medium at the inlet of the receiver, and the controlled variable is the temperature of the heat transfer medium at the outlet of the receiver; (3) the whole day The maximum net power generation of the power station is the optimization goal, and a dynamic optimization problem is constructed; (4) The control variables of the continuous NLP optimization problem are discretized by CVP_SS, and then the SQP algorithm is used to solve it. In the present invention, the operation optimization method of the receiver of the tower solar power station, under the premise of ensuring the smooth operation of the receiver, simultaneously improves the net power generation of the power station, and provides a reference for the commercial operation of the tower solar power station.

Description

Operational Optimization Method for Tower Solar Power Plant Receiver

技术领域technical field

本发明涉及太阳能发电技术领域，特别是涉及接收器装置，提供了一种针对塔式太阳能接收器的运行优化方法。The invention relates to the technical field of solar power generation, in particular to a receiver device, and provides an operation optimization method for a tower solar receiver.

背景技术Background technique

塔式太阳能热电站利用多个独立跟踪太阳的定日镜装置，将太阳光聚焦到一个固定在接收塔顶部的接收器上，加热流经接收器内部的传热介质成为高温工质，再利用高温工质的热能带动汽轮机、发电机发电。它是所有大规模太阳能发电技术中成本最低、聚光集热效率最高的一种，有着广泛的应用前景。The tower-type solar thermal power station uses multiple heliostat devices that independently track the sun to focus the sunlight on a receiver fixed on the top of the receiving tower, heat the heat transfer medium flowing through the receiver to become a high-temperature working fluid, and reuse The heat energy of the high-temperature working medium drives the steam turbine and generator to generate electricity. It is the one with the lowest cost and the highest concentration and heat collection efficiency among all large-scale solar power generation technologies, and has broad application prospects.

在塔式太阳能热电站中，接收器的功能是吸收定日镜聚焦的太阳能并用于加热其内部流动的传热介质产生高温热能。传热介质的工作温度将影响整个电站的净发电效率，传统上认为传热介质的工作温度越高越好，这是因为温度越高功率转换系统(一般为朗肯循环系统)的效率越高且系统消耗的泵能也将越小。然而，传热工质工作温度的增高必然会导致系统热损失的增大。因此，在太阳能电站中，对传热工质工作温度进行优化具有重要的意义。In the tower solar thermal power plant, the function of the receiver is to absorb the solar energy focused by the heliostat and use it to heat the heat transfer medium flowing inside it to generate high temperature heat energy. The operating temperature of the heat transfer medium will affect the net power generation efficiency of the entire power station. Traditionally, it is believed that the higher the operating temperature of the heat transfer medium, the better, because the higher the temperature, the higher the efficiency of the power conversion system (generally a Rankine cycle system) And the pump energy consumed by the system will be smaller. However, an increase in the working temperature of the heat transfer working fluid will inevitably lead to an increase in the heat loss of the system. Therefore, in a solar power station, it is of great significance to optimize the working temperature of the heat transfer fluid.

目前国内外对太阳能接收器运行优化的研究很少。在现有的接收器运行优化的研究中，有的技术将功率转换系统的转换效率视为与接收器运行温度无关的常数，忽略接收器出口温度对功率转换系统的影响；有的技术在运行优化过程中采用的接收器模型为集总参数模型，忽略了接收器的典型分布参数特性，不能很好地反映电站实际情况。At present, there are few researches on the operation optimization of solar receivers at home and abroad. In the existing research on receiver operation optimization, some technologies regard the conversion efficiency of the power conversion system as a constant independent of the receiver operating temperature, ignoring the influence of the receiver outlet temperature on the power conversion system; The receiver model used in the optimization process is a lumped parameter model, which ignores the typical distributed parameter characteristics of the receiver and cannot reflect the actual situation of the power station well.

发明内容Contents of the invention

本发明提供了一种塔式太阳能热电站接收器的运行优化方法，保证接收器平稳运行的前提下，同时提高了电站的净发电量，为塔式太阳能电站的商业化运行提供了参考。The invention provides an operation optimization method for a receiver of a tower-type solar thermal power station, which improves the net power generation of the power station while ensuring the smooth operation of the receiver, and provides a reference for the commercial operation of the tower-type solar thermal power station.

本发明采用的技术方案如下：The technical scheme that the present invention adopts is as follows:

一种塔式太阳能电站接收器的运行优化方法的步骤如下：The steps of an operation optimization method for a tower-type solar power plant receiver are as follows:

1)搭建塔式太阳能电站接收器的分布参数模型并仿真得到不同光照强度下，当电站净发电效率最高时，接收器出口温度的数值；1) Build the distribution parameter model of the receiver of the tower solar power plant and simulate to obtain the value of the outlet temperature of the receiver when the net power generation efficiency of the power plant is the highest under different light intensities;

2)设计PID控制器，其中控制器的控制变量为接收器入口处传热介质流速，被控变量为接收器出口处传热介质温度；2) Design a PID controller, wherein the control variable of the controller is the flow rate of the heat transfer medium at the inlet of the receiver, and the controlled variable is the temperature of the heat transfer medium at the outlet of the receiver;

3)以全天电站净发电量最大为优化目标，构造优化问题；3) Taking the maximum net power generation of the power station throughout the day as the optimization goal, construct an optimization problem;

4)通过CVP_SS将连续NLP优化问题的控制变量离散化，进而采用SQP算法进行求解，得到电站全天发电量最大时接收器出口处传热介质温度设定值的变化曲线。4) The control variables of the continuous NLP optimization problem are discretized by CVP_SS, and then the SQP algorithm is used to solve the problem, and the change curve of the temperature setting value of the heat transfer medium at the outlet of the receiver is obtained when the power station generates the maximum power throughout the day.

所述的步骤1)为：Described step 1) is:

1.1根据能量守恒方程，接收器的分布参数模型为：1.1 According to the energy conservation equation, the distributed parameter model of the receiver is:

${ρ ρ}_{m m} {C C}_{m m} {V V}_{m m} \frac{\partial \partial {T T}_{m m}}{\partial \partial t t} = = {Iη Iη}_{o o p p t t} {A A}_{m m i i r r r r o o r r} - - {ϵσA ϵσA}_{o o} {T T}_{m m}^{44} - - {h h}_{o o} {A A}_{o o} (({T T}_{m m} - - {T T}_{a a})) - - {h h}_{i i} {A A}_{i i} (({T T}_{m m} - - {T T}_{f f})) - - - - - - ((11))$

${ρ ρ}_{f f} {C C}_{f f} {V V}_{f f} \frac{\partial \partial {T T}_{f f}}{\partial \partial t t} + + {ρ ρ}_{f f} {C C}_{f f} m m \frac{\partial \partial {T T}_{f f}}{\partial \partial x x} = = {h h}_{i i} {A A}_{i i} (({T T}_{m m} - - {T T}_{f f})) - - - - - - ((22))$

其中，A_i为接收器管壁内表面面积，A_mirror为定日镜场总面积，A_o为接收器管道受光面外部面积，C_m为接收器管壁比热，C_f为传热介质比热，h_i为接收器管壁与内部传热介质对流换热系数，h_o为接收器管壁与外部环境对流换热系数，I为光照强度，m为传热介质流速，t为时间，T_a为环境温度，T_f为传热介质温度，T_m为接收器管壁温度，V_f为接收器管道内传热介质体积，V_m为接收器管壁体积，x为接收器长度，ε黑度，η_opt为镜场综合效率，ρ_f为传热介质密度，ρ_m为接收器管壁密度，σ为黑体辐射常数；Among them, A _i is the inner surface area of the receiver tube wall, A _mirror is the total area of the heliostat field, A _o is the external area of the light-receiving surface of the receiver tube, C _m is the specific heat of the receiver tube wall, and C _f is the heat transfer medium Specific heat, h _i is the convective heat transfer coefficient between the receiver tube wall and the internal heat transfer medium, h _o is the convective heat transfer coefficient between the receiver tube wall and the external environment, I is the light intensity, m is the flow rate of the heat transfer medium, and t is the time , T _a is the ambient temperature, T _f is the temperature of the heat transfer medium, T _m is the temperature of the receiver tube wall, V _f is the volume of the heat transfer medium in the receiver tube, V _m is the volume of the receiver tube wall, and x is the length of the receiver , ε blackness, η _opt is the overall efficiency of the mirror field, ρ _f is the density of the heat transfer medium, ρ _m is the density of the receiver tube wall, and σ is the blackbody radiation constant;

1.2选取太阳光照强度I分别为I₀、I₀+Δ、I₀+2Δ、I₀+3Δ、I₀+4Δ的典型值；其中I₀为电站能否发电的最低光照强度，I₀+4Δ为一天内最大光照强度；1.2 Select the typical values of solar light intensity I as I ₀ , I ₀ +Δ, I ₀ +2Δ, I ₀ +3Δ, I ₀ +4Δ; where I ₀ is the minimum light intensity for whether the power station can generate electricity, and I ₀ + 4Δ is the maximum light intensity in one day;

1.3塔式太阳能电站接收器部件的运行优化需要对功率转换系统以及电泵做如下计算：1.3 The operation optimization of the tower solar power plant receiver components requires the following calculations for the power conversion system and the electric pump:

功率转换系统等效为一个朗肯循环模型，其转换效率η_rank为：The power conversion system is equivalent to a Rankine cycle model, and its conversion efficiency η _rank is:

${η η}_{r r a a n no k k} = = {K K}_{11} ((11 - - \frac{{T T}_{a a}}{{T T}_{o o u u t t}})) - - - - - - ((33))$

其中，T_out为接收器出口处温度，Among them, T _out is the temperature at the outlet of the receiver,

电泵消耗的功率P_pump为：The power P _{pump consumed by the electric pump} is:

${P P}_{p p u u m m p p} = = \frac{{K K}_{22} {Lm L m}^{33}}{{gπ gπ}^{22} {d d}^{55} {η η}_{p p u u m m p p}} - - - - - - ((44))$

其中，K₁、K₂与g为常数，L为管道的长度，d为管道的直径；Among them, K ₁ , K ₂ and g are constants, L is the length of the pipeline, and d is the diameter of the pipeline;

同时，接收器内流动的传热介质吸收的功率P_solar为：At the same time, the power P _solar absorbed by the heat transfer medium flowing in the receiver is:

P_solar＝mC_f(T_out-T_fin)(5)P _solar ＝mC _f (T _out -T _fin )(5)

因此，电站在某固定太阳光照强度下的净发电功率P_net为：Therefore, the net generating power P _net of the power station under a fixed solar intensity is:

${P P}_{n no e e t t} = = {P P}_{s the s o o l l a a r r} {η η}_{r r a a n no k k} - - {P P}_{p p u u m m p p} = = {mC mC}_{f f} (({T T}_{o o u u t t} - - {T T}_{f f i i n no})) \times \times {K K}_{11} ((11 - - \frac{{T T}_{a a}}{{T T}_{o o u u t t}})) - - \frac{{K K}_{22} {Lm L m}^{33}}{{gπ gπ}^{22} {d d}^{55} {η η}_{p p u u m m p p}} - - - - - - ((66))$

1.4仿真得到不同光照强度I下电站净发电效率关于接收器出口处传热介质温度的曲线，其中，净发电效率η_net的计算公式为：1.4 The curves of the net power generation efficiency of the power station with respect to the temperature of the heat transfer medium at the outlet of the receiver are obtained by simulation under different light intensities I, where the calculation formula of the net power generation efficiency η _net is:

${η η}_{n no e e t t} = = \frac{{P P}_{n no e e t t}}{{IA IA}_{m m i i r r r r o o r r}} = = \frac{{P P}_{s the s o o l l a a r r} {η η}_{r r a a n no k k} - - {P P}_{p p u u m m p p}}{{IA IA}_{m m i i r r r r o o r r}} - - - - - - ((77))$

其中，I为步骤1.2中选定的某一典型值，Wherein, I is a certain typical value selected in step 1.2,

1.5通过曲线观察电站净发电效率关于接收器出口处传热介质温度的关系，得到当净发电效率最高时，接收器出口处传热介质的温度。1.5 Observe the relationship between the net power generation efficiency of the power station and the temperature of the heat transfer medium at the outlet of the receiver through the curve, and obtain the temperature of the heat transfer medium at the outlet of the receiver when the net power generation efficiency is the highest.

所述的步骤2)为：Described step 2) is:

采用前馈加单回路反馈的复合控制系统，确定前馈控制器的K_p1以及单回路反馈控制器的K_p2与K_I，使得被控变量接收器出口处传热介质温度能够跟踪设定值。A composite control system of feedforward plus single-loop feedback is adopted to determine K _p1 of the feedforward controller and K _p2 and K _I of the single-loop feedback controller, so that the temperature of the heat transfer medium at the outlet of the controlled variable receiver can track the set value .

所述的步骤3)为：Described step 3) is:

当不考虑电价变化的影响时，电站收益的影响因素是能量转换过程中的热损失以及运行的操作成本，即电站能够提供的净发电量，电站一天内n个小时的总发电量为各个小时发电量的积分，考虑到实际意义，以决策变量即优化变量为接收器出口处传热介质温度的设定值、全天电站净发电量最大为优化目标的优化命题可描述为：When the impact of electricity price changes is not considered, the factors affecting the power station revenue are the heat loss in the energy conversion process and the operating cost of operation, that is, the net power generation that the power station can provide, and the total power generation of the power station for n hours in a day is each hour For the integration of power generation, considering the practical significance, the optimization proposition with the decision variable, that is, the optimization variable, as the set value of the temperature of the heat transfer medium at the outlet of the receiver, and the maximum net power generation of the power station throughout the day as the optimization goal can be described as:

max $Q = {&Integral;}_{t_{1}}^{t_{n}} P_{n e t} (t) d t$ max $Q = {&Integral;}_{t_{1}}^{t_{no}} P_{no e t} (t) d t$

$s the s . . t t . . \{\begin{matrix} {P P}_{r r} \leq \leq {P P}_{n no e e t t} \leq \leq {P P}_{m m a a x x} \\ {P P}_{n no e e t t} (({t t}_{i i})) - - {P P}_{n no e e t t} (({t t}_{i i - - 11})) \leq \leq {ΔP ΔP}_{n no e e t t} \\ {m m}_{m m i i n no} \leq \leq m m \leq \leq {m m}_{m m a a x x} \\ {T T}_{f f min min} ((x x,, {t t}_{i i})) \leq \leq {T T}_{f f} ((x x,, {t t}_{i i})) \leq \leq {T T}_{f f m m a a x x} ((x x,, {t t}_{i i})) \\ {T T}_{f f} ((x x,, {t t}_{i i})) - - {T T}_{f f} ((x x,, {t t}_{i i - - 11})) \leq \leq {ΔT ΔT}_{f f m m a a x x} \end{matrix} - - - - - - ((88))$

。.

所述的步骤4)为：Described step 4) is:

步骤3)中的优化命题为连续的非线性问题，在求解上采用基于控制向量参数化方法的CVP_SS方法，仅离散化控制向量而保持状态向量不变，将两点边界值问题转化为初值问题进行求解，具体实现步骤如下：The optimization proposition in step 3) is a continuous nonlinear problem, and the CVP_SS method based on the control vector parameterization method is used to solve it, only the control vector is discretized and the state vector is kept unchanged, and the two-point boundary value problem is transformed into an initial value To solve the problem, the specific implementation steps are as follows:

4.1初始化，设定时间分段常数N，将时间区间[0,T]分成N段，每段的时间长度为δ_k，k＝1,…，N，这些量不一定要全部相等，但是要满足下列的方程：4.1 Initialization, set the time segment constant N, divide the time interval [0, T] into N segments, the length of each segment is δ _k , k=1,..., N, these quantities do not have to be all equal, but must satisfy the following equation:

$T T = = {Σ Σ}_{k k = = 11}^{N N} {δ δ}_{k k} - - - - - - ((99))$

将控制变量u(t)即优化问题的决策变量按照时间的分段离散成参数向量ζ，动态优化问题就转化为非线性规划问题；The control variable u(t), which is the decision variable of the optimization problem, is discretized into a parameter vector ζ according to the time segment, and the dynamic optimization problem is transformed into a nonlinear programming problem;

4.2设定参数向量的初始值置j＝0，其中，k表示第k个时间分段；4.2 Set the initial value of the parameter vector Set j=0, wherein, k represents the kth time segment;

4.3根据计算得到目标函数值Q_j；4.3 According to Calculate the objective function value Q _j ;

4.4计算梯度信息▽Q_j，并根据梯度基于SQP算法获得下一迭代点 4.4 Calculate the gradient information ▽Q _j , and obtain the next iteration point based on the gradient based on the SQP algorithm

4.5若满足停止准则，则算法终止；否则，置j＝j+1；重复步骤4.3和4.4。4.5 If the stop criterion is met, the algorithm is terminated; otherwise, set j=j+1; repeat steps 4.3 and 4.4.

附图说明Description of drawings

图1是塔式太阳能热电站接收器运行优化方法流程图；Fig. 1 is a flowchart of a method for optimizing the operation of a tower-type solar thermal power station receiver;

图2是实例中的接收器内传热介质流动示意图；Fig. 2 is a schematic diagram of the flow of heat transfer medium in the receiver in the example;

图3是实例中的接收器控制系统方块图；Fig. 3 is the receiver control system block diagram in the example;

图4是实例中电站净发电效率在不同光照强度下随温度变化的曲线；Figure 4 is the curve of the net power generation efficiency of the power station in the example as a function of temperature under different light intensities;

图5是实例中太阳光照强度变化曲线；Fig. 5 is the variation curve of sunlight intensity in the example;

图6是实例中电站发电量优化结果与未优化结果对比。Figure 6 is a comparison of the optimized and unoptimized results of power generation in the example.

具体实施方式Detailed ways

如图1所示，一种塔式太阳能电站接收器的运行优化方法的步骤如下：As shown in Figure 1, the steps of an operation optimization method for a tower-type solar power plant receiver are as follows:

所述的步骤1)为：Described step 1) is:

其中，A_i为接收器管壁内表面面积，A_mirror为定日镜场总面积，A_o为接收器管道受光面外部面积，C_m为接收器管壁比热，C_f为传热介质比热，h_i为接收器管壁与内部传热介质对流换热系数，h_o为接收器管壁与外部环境对流换热系数，I为光照强度，m为传热介质流速，t为时间，T_a为环境温度，T_f为传热介质温度，T_m为接收器管壁温度，V_f为接收器管道内传热介质体积，V_m为接收器管壁体积，x为接收器长度，ε黑度，η_opt为镜场综合效率，ρ_f为传热介质密度，ρ_m为接收器管壁密度，σ为黑体辐射常数；Among them, A _i is the inner surface area of the receiver tube wall, A _mirror is the total area of the heliostat field, A _o is the external area of the light-receiving surface of the receiver tube, C _m is the specific heat of the receiver tube wall, and C _f is the heat transfer medium Specific heat, h _i is the convective heat transfer coefficient between the receiver tube wall and the internal heat transfer medium, h _o is the convective heat transfer coefficient between the receiver tube wall and the external environment, I is the light intensity, m is the flow rate of the heat transfer medium, and t is the time , T _a is the ambient temperature, T _f is the temperature of the heat transfer medium, T _m is the temperature of the receiver tube wall, V _f is the volume of the heat transfer medium in the receiver tube, V _m is the volume of the receiver tube wall, and x is the length of the receiver , ε blackness, η _opt is the overall efficiency of the mirror field, ρ _f is the density of the heat transfer medium, ρ _m is the density of the receiver tube wall, and σ is the black body radiation constant;

P_solar＝mC_f(T_out-T_fin)(5)P _solar ＝mC _f (T _out -T _fin )(5)

所述的步骤2)为：Described step 2) is:

所述的步骤3)为：Described step 3) is:

当不考虑电价变化的影响时，电站收益的影响因素是能量转换过程中的热损失以及运行的操作成本，即电站能够提供的净发电量，电站一天内n个小时的总发电量为各个小时发电量的积分，考虑到实际意义，以决策变量即优化变量为接收器出口处传热介质温度的设定值、全天电站净发电量最大为优化目标的优化命题可描述为：When the impact of electricity price changes is not considered, the influencing factors of power station revenue are the heat loss in the energy conversion process and the operating cost of operation, that is, the net power generation that the power station can provide, and the total power generation of the power station for n hours in a day is each hour For the integration of power generation, considering the practical significance, the optimization proposition with the decision variable, that is, the optimization variable, as the set value of the temperature of the heat transfer medium at the outlet of the receiver, and the maximum net power generation of the power station throughout the day as the optimization goal can be described as:

。.

所述的步骤4)为：Described step 4) is:

$T T = = {Σ Σ}_{k k = = 11}^{N N} {δ δ}_{k k} - - - - - - ((99))$

基于图2所示的以熔盐为传热介质的塔式太阳能接收器仿真对象采用本发明进行了优化。该电站接收器为高6.2m，直径5.1m的圆柱形，由24块接收板组成，每块板有32根竖直向上的吸热管，吸热管管道直径2.1cm，吸热管管壁厚度1.2mm。以该电站为原型搭建分布参数模型，并设计控制变量为接收器入口处传热介质流速，被控变量为接收器出口处的传热介质温度的控制器，其控制系统方块图如图3所示。在不同光照强度下(选取典型的400、500、600、700、800)仿真得到的电站净发电效率对温度的曲线如图4所示，可以看出电站净发电效率随着接收器出口温度增大不断增大，达到最大值以后反而会随着温度的增大而减小。采用不同光照强度下电站净发电效率最大时接收器出口温度为初始值对连续变化时间为6:30到17:00的电站进行优化，此时太阳光照强度的变化如图5所示。经优化后电站净发电量与未优化结果对比如图6所示，当光照强度不强时，优化前后电站净发电量的增量不是很高，最小增长率发生在6:30到7:00之间，仅为1.15％；当在正午时分光照强度最强时，电站净发电量的增量达到最高，为8.28％；一天内优化后电站净发电量的平均增长率为6.76％。Based on the simulation object of the tower type solar receiver with molten salt as the heat transfer medium shown in Fig. 2, the present invention is used for optimization. The receiver of the power station is cylindrical with a height of 6.2m and a diameter of 5.1m. It is composed of 24 receiving plates, and each plate has 32 vertically upward heat-absorbing tubes. Thickness 1.2mm. Taking the power station as a prototype to build a distributed parameter model, and design a controller whose control variable is the flow rate of the heat transfer medium at the inlet of the receiver, and the controlled variable is the temperature of the heat transfer medium at the outlet of the receiver. The block diagram of the control system is shown in Figure 3 Show. The curves of the net power generation efficiency of the power station versus temperature obtained by simulation under different light intensities (typically 400, 500, 600, 700, and 800) are shown in Figure 4. It can be seen that the net power generation efficiency of the power station increases with the outlet temperature of the receiver. After reaching the maximum value, it will decrease with the increase of temperature. Using the receiver outlet temperature as the initial value when the net power generation efficiency of the power station is maximum under different light intensities, the power station with a continuous change time of 6:30 to 17:00 is optimized. The comparison between the net power generation of the optimized power station and the unoptimized results is shown in Figure 6. When the light intensity is not strong, the increment of the net power generation of the power station before and after optimization is not very high, and the minimum growth rate occurs between 6:30 and 7:00 Between them, it is only 1.15%; when the light intensity is the strongest at noon, the increment of the net power generation of the power station reaches the highest, which is 8.28%; the average growth rate of the net power generation of the power station after optimization in one day is 6.76%.

Claims

1. A method for optimizing operation of a tower type solar power plant receiver, characterized in that its steps are as follows:

1) Build the distribution parameter model of the receiver of the tower solar power plant and simulate to obtain the value of the outlet temperature of the receiver when the net power generation efficiency of the power plant is the highest under different light intensities;

2) Design a PID controller, wherein the control variable of the controller is the flow rate of the heat transfer medium at the inlet of the receiver, and the controlled variable is the temperature of the heat transfer medium at the outlet of the receiver;

3) Taking the maximum net power generation of the power station throughout the day as the optimization goal, construct an optimization problem;

4) The control variables of the continuous NLP optimization problem are discretized by CVP_SS, and then the SQP algorithm is used to solve the problem, and the change curve of the temperature setting value of the heat transfer medium at the outlet of the receiver is obtained when the power station generates the maximum power throughout the day.

2. the operation optimization method of a kind of tower type solar power plant receiver as claimed in claim 1, is characterized in that described step 1) is:

1.1 According to the energy conservation equation, the distributed parameter model of the receiver is:

{ρ ρ}_{m m} {C C}_{m m} {V V}_{m m} \frac{\partial \partial {T T}_{m m}}{\partial \partial t t} = = {Iη Iη}_{o o p p t t} {A A}_{m m i i r r r r o o r r} - - {ϵσA ϵσA}_{o o} {T T}_{m m}^{44} - - {h h}_{o o} {A A}_{o o} (({T T}_{m m} - - {T T}_{a a})) - - {h h}_{i i} {A A}_{i i} (({T T}_{m m} - - {T T}_{f f})) - - - - - - ((11))

{ρ ρ}_{f f} {C C}_{f f} {V V}_{f f} \frac{\partial \partial {T T}_{f f}}{\partial \partial t t} + + {ρ ρ}_{f f} {C C}_{f f} m m \frac{\partial \partial {T T}_{f f}}{\partial \partial x x} = = {h h}_{i i} {A A}_{i i} (({T T}_{m m} - - {T T}_{f f})) - - - - - - ((22))

Among them, A _i is the inner surface area of the receiver tube wall, A _mirror is the total area of the heliostat field, A _o is the external area of the light-receiving surface of the receiver tube, C _m is the specific heat of the receiver tube wall, and C _f is the heat transfer medium Specific heat, h _i is the convective heat transfer coefficient between the receiver tube wall and the internal heat transfer medium, h _o is the convective heat transfer coefficient between the receiver tube wall and the external environment, I is the light intensity, m is the flow rate of the heat transfer medium, and t is the time , T _a is the ambient temperature, T _f is the temperature of the heat transfer medium, T _m is the temperature of the receiver tube wall, V _f is the volume of the heat transfer medium in the receiver tube, V _m is the volume of the receiver tube wall, and x is the length of the receiver , ε blackness, η _opt is the overall efficiency of the mirror field, ρ _f is the density of the heat transfer medium, ρ _m is the density of the receiver tube wall, and σ is the blackbody radiation constant;

1.2 Select the typical values of solar light intensity I as I ₀ , I ₀ +Δ, I ₀ +2Δ, I ₀ +3Δ, I ₀ +4Δ; where I ₀ is the minimum light intensity for whether the power station can generate electricity, and I ₀ + 4Δ is the maximum light intensity in one day;

1.3 The operation optimization of the tower solar power plant receiver components requires the following calculations for the power conversion system and the electric pump:

The power conversion system is equivalent to a Rankine cycle model, and its conversion efficiency η _rank is:

{η η}_{r r a a n no k k} = = {K K}_{11} ((11 - - \frac{{T T}_{a a}}{{T T}_{o o u u t t}})) - - - - - - ((33))

Among them, T _out is the temperature at the outlet of the receiver,

The power P _{pump consumed by the electric pump} is:

{P P}_{p p u u m m p p} = = \frac{{K K}_{22} {Lm L m}^{33}}{{gπ gπ}^{22} {d d}^{55} {η η}_{p p u u m m p p}} - - - - - - ((44))

Among them, K ₁ , K ₂ and g are constants, L is the length of the pipeline, and d is the diameter of the pipeline;

At the same time, the power P _solar absorbed by the heat transfer medium flowing in the receiver is:

P _solar ＝mC _f (T _out -T _fin )(5)

Therefore, the net generating power P _net of the power station under a fixed solar intensity is:

{P P}_{n no e e t t} = = {P P}_{s the s o o l l a a r r} {η η}_{r r a a n no k k} - - {P P}_{p p u u m m p p} = = {mC mC}_{f f} (({T T}_{o o u u t t} - - {T T}_{f f i i n no})) \times \times {K K}_{11} ((11 - - \frac{{T T}_{a a}}{{T T}_{o o u u t t}})) - - \frac{{K K}_{22} {Lm L m}^{33}}{{gπ gπ}^{22} {d d}^{55} {η η}_{p p u u m m p p}} - - - - - - ((66))

1.4 The curves of the net power generation efficiency of the power station with respect to the temperature of the heat transfer medium at the outlet of the receiver are obtained by simulation under different light intensities I, where the calculation formula of the net power generation efficiency η _net is:

{η η}_{n no e e t t} = = \frac{{P P}_{n no e e t t}}{{IA IA}_{m m i i r r r r o o r r}} = = \frac{{P P}_{s the s o o l l a a r r} {η η}_{r r a a n no k k} - - {P P}_{p p u u m m p p}}{{IA IA}_{m m i i r r r r o o r r}} - - - - - - ((77))

Wherein, I is a certain typical value selected in step 1.2,

1.5 Observe the relationship between the net power generation efficiency of the power station and the temperature of the heat transfer medium at the outlet of the receiver through the curve, and obtain the temperature of the heat transfer medium at the outlet of the receiver when the net power generation efficiency is the highest.

3. the operation optimization method of a kind of tower type solar power plant receiver as claimed in claim 1, is characterized in that described step 2) is:

A composite control system of feedforward plus single-loop feedback is adopted to determine K _p1 of the feedforward controller and K _p2 and K _I of the single-loop feedback controller, so that the temperature of the heat transfer medium at the outlet of the controlled variable receiver can track the set value .

4. the operation optimization method of a kind of tower type solar power plant receiver as claimed in claim 1, is characterized in that described step 3) is:

When the impact of electricity price changes is not considered, the influencing factors of power station revenue are the heat loss in the energy conversion process and the operating cost of operation, that is, the net power generation that the power station can provide, and the total power generation of the power station for n hours in a day is each hour For the integration of power generation, considering the practical significance, the optimization proposition with the decision variable, that is, the optimization variable, as the set value of the temperature of the heat transfer medium at the outlet of the receiver, and the maximum net power generation of the power station throughout the day as the optimization goal can be described as:

\begin{matrix} max max & Q Q = = {&Integral; &Integral;}_{{t t}_{11}}^{{t t}_{n no}} {P P}_{n no e e t t} ((t t)) d d t t \end{matrix}

\begin{matrix} s the s . . t t . . & \{\begin{matrix} {P P}_{r r} \leq \leq {P P}_{n no e e t t} \leq \leq {P P}_{m m a a x x} \\ {P P}_{n no e e t t} (({t t}_{i i})) - - {P P}_{n no e e t t} (({t t}_{i i - - 11})) \leq \leq {ΔP ΔP}_{n no e e t t} \\ {m m}_{m m i i n no} \leq \leq m m \leq \leq {m m}_{m m a a x x} \\ {T T}_{f f min min} ((x x,, {t t}_{i i})) \leq \leq {T T}_{f f} ((x x,, {t t}_{i i})) \leq \leq {T T}_{f f m m a a x x} ((x x,, {t t}_{i i})) \\ {T T}_{f f} ((x x,, {t t}_{i i})) - - {T T}_{f f} ((x x,, {t t}_{i i - - 11})) \leq \leq {ΔT ΔT}_{f f m m a a x x} \end{matrix} \end{matrix} - - - - - - ((88)) . .

5. the operation optimization method of a kind of tower type solar power plant receiver as claimed in claim 1, is characterized in that described step 4) is:

The optimization proposition in step 3) is a continuous nonlinear problem, and the CVP_SS method based on the control vector parameterization method is used to solve it, only the control vector is discretized and the state vector is kept unchanged, and the two-point boundary value problem is transformed into an initial value To solve the problem, the specific implementation steps are as follows:

4.1 Initialization, set the time segment constant N, divide the time interval [0, T] into N segments, the length of each segment is δ _k , k=1,..., N, these quantities do not have to be all equal, but must satisfy the following equation:

T T = = {Σ Σ}_{k k = = 11}^{N N} {δ δ}_{k k} - - - - - - ((99))

The control variable u(t), which is the decision variable of the optimization problem, is discretized into a parameter vector ζ according to the time segment, and the dynamic optimization problem is transformed into a nonlinear programming problem;

4.2 Set the initial value of the parameter vector Set j=0, wherein, k represents the kth time segment;

4.3 According to Calculate the objective function value Q _j ;

4.4 Calculate the gradient information ▽Q _j , and obtain the next iteration point based on the gradient based on the SQP algorithm

4.5 If the stop criterion is met, the algorithm is terminated; otherwise, set j=j+1; repeat steps 4.3 and 4.4.