阅读说明：本技术 一种海洋温差能系统透平输出功自适应控制系统及方法 (Turbine output power self-adaptive control system and method for ocean temperature difference energy system ) 是由 兰志刚 于汀 吴勇虎 谭越 孙洋洲 于 2019-10-17 设计创作，主要内容包括：本发明涉及一种海洋温差能系统透平输出功自适应控制系统及方法,其特征在于,包括温度传感器和信号采集控制器；四个所述温度传感器分别设置在海洋温差能系统的温海水回路和冷海水回路中热交换器的入口和出口处,用于实时测量温海水回路和冷海水回路中热交换器的入口温度和出口温度；所述信号采集控制器分别电连接四个所述温度传感器,用于采用自适应算法,根据实时测量的入口温度和出口温度,实时计算使所述海洋温差能系统中透平达到稳定输出所需的海水流速,并根据实时计算的海水流速,实时控制所述海洋温差能系统中海水泵的流速,使所述海洋温差能系统的透平达到稳定输出的工作状态,本发明可以广泛应用于海洋温差能发电领域中。(The invention relates to a turbine output power self-adaptive control system and a method of an ocean temperature difference energy system, which are characterized by comprising a temperature sensor and a signal acquisition controller; the four temperature sensors are respectively arranged at the inlet and the outlet of the heat exchanger in the warm seawater loop and the cold seawater loop of the ocean temperature difference energy system and are used for measuring the inlet temperature and the outlet temperature of the heat exchanger in the warm seawater loop and the cold seawater loop in real time; the signal acquisition controller is respectively and electrically connected with the four temperature sensors and is used for calculating the flow velocity of the seawater required by stable output of the turbine in the ocean temperature difference energy system in real time according to the inlet temperature and the outlet temperature measured in real time by adopting a self-adaptive algorithm, and controlling the flow velocity of the seawater pump in the ocean temperature difference energy system in real time according to the calculated flow velocity of the seawater in real time so as to ensure that the turbine of the ocean temperature difference energy system reaches the working state of stable output.)

1. A self-adaptive control system for turbine output power of an ocean temperature difference energy system is characterized by comprising a temperature sensor and a signal acquisition controller;

the four temperature sensors are respectively arranged at the inlet and the outlet of the heat exchanger in the warm seawater loop and the cold seawater loop of the ocean temperature difference energy system and are used for measuring the inlet temperature and the outlet temperature of the heat exchanger in the warm seawater loop and the cold seawater loop in real time;

the signal acquisition controller is respectively and electrically connected with the four temperature sensors and is used for calculating the flow velocity of the seawater required by stable output of the turbine in the ocean temperature difference energy system in real time according to the inlet temperature and the outlet temperature measured in real time by adopting a self-adaptive algorithm, and controlling the flow velocity of the seawater pump in the ocean temperature difference energy system in real time according to the calculated flow velocity of the seawater in real time so as to ensure that the turbine of the ocean temperature difference energy system reaches the working state of stable output.

2. The adaptive control system for turbine output power of an ocean thermal energy system according to claim 1, wherein the seawater pump in the ocean thermal energy system comprises a warm seawater pump and a cold seawater pump, and a controllable flow pump with flow rate measurement and control is adopted.

3. The adaptive control system for turbine output power of an ocean thermal energy system of claim 1, wherein the heat exchanger in the warm seawater loop is an evaporator and the heat exchanger in the cold seawater loop is a condenser.

4. A self-adaptive control method for turbine output power of an ocean temperature difference energy system is characterized by comprising the following steps:

1) temperature sensors are respectively arranged at the inlet and the outlet of a heat exchanger in a warm seawater loop and a cold seawater loop of the ocean temperature difference energy system;

2) the four temperature sensors respectively measure the inlet temperature of the warm seawater of the heat exchanger, the outlet temperature of the warm seawater of the heat exchanger, the inlet temperature of the cold seawater of the heat exchanger and the outlet temperature of the cold seawater of the heat exchanger, and send the measured temperature data to the signal acquisition controller;

3) the signal acquisition controller adopts a self-adaptive algorithm, calculates the flow velocity of the seawater required by the stable output of the turbine in the ocean temperature difference energy system in real time according to the temperature data measured in real time, and controls the flow velocity of the seawater pump in the ocean temperature difference energy system in real time according to the flow velocity of the seawater calculated in real time, so that the turbine of the ocean temperature difference energy system reaches the working state of stable output.

5. The adaptive control method for turbine output power of an ocean thermal energy system according to claim 4, wherein the adaptive algorithm in the step 3) comprises the following steps:

flow velocity V of warm seawater in warm seawater loop_wsInlet temperature of seawater according to temperature

wherein A is_EIs the heat exchange area, U, of a heat exchanger in a warm seawater loop_EIs the heat exchange coefficient of the heat exchanger in the warm seawater loop,

when the temperature of the ocean warm sea water changes, according to the measured inlet temperature and outlet temperature of the warm sea water and the flow velocity V of the warm sea water in the warm sea water loop_wsInlet temperature of seawater according to temperature

cold seawater flow velocity V_csInlet temperature of cold seawater

wherein A is_CIs the heat exchange area, U, of a heat exchanger in a cold seawater loop_CThe heat exchange coefficient of the heat exchanger in the cold seawater loop,the specific heat of the cold sea water is used,

when the temperature of the cold seawater in the ocean changes, according to the measured inlet temperature and outlet temperature of the cold seawater and the flow velocity V of the cold seawater_csInlet temperature of cold seawaterThe variable relation can adaptively adjust the flow rate of the cold sea water pump in the ocean temperature difference energy system, so that the ocean temperature difference energy system can maintain the constant condensation temperature, and further the output stability of turbine power in the ocean temperature difference energy system can be ensured.

Technical Field

The invention relates to a self-adaptive control system and a self-adaptive control method for turbine output power of an ocean temperature difference energy system, and belongs to the field of ocean temperature difference energy power generation.

Background

The ocean thermal energy power generation is a power generation mode which converts thermal energy into electric energy through thermodynamic cycle by utilizing the temperature difference between ocean surface layer warm seawater and deep layer cold seawater. Common thermodynamic cycle modes comprise Rankine cycle, kalina cycle and previous cycle, wherein the Rankine cycle uses a working medium with a low boiling point to circulate in a closed circuit, and meanwhile, the Rankine cycle has the advantages of simple structure and relatively small size of a device (particularly a turbine unit), and industrial development and popularization are easy to realize, so that the Rankine cycle is the most common cycle mode. The Rankine cycle-based ocean temperature difference energy system comprises a turbine, a condenser, a working medium pump and an evaporator, and the specific structure is shown in figure 1.

Because the temperature difference of cold and heat sources of the ocean temperature difference energy system is small, the conversion efficiency of the system is low, and the stability of the operation of the system and the sensitivity of output work to the change of internal and external parameters of the system are determined. Therefore, the system must be adjusted to match the relevant system parameters to achieve a stable operation. In view of the fact that after the ocean temperature difference energy system is designed, the types of working media, system components and thermodynamic cycle parameters are solidified, and only the seawater temperature and the seawater flow related to cold and heat sources are left in the parameters influencing the operation of the system. Because the temperature of the seawater is influenced by sunshine and seasons, periodic change and irregular change of days, months, years and the like exist, so that the input working condition of the ocean temperature difference energy system fluctuates, if the flow parameter of the seawater is not correspondingly adjusted, the system deviates from an optimized operation state, and the output efficiency of a turbine of the system is reduced, however, a self-adaptive control method for realizing stable output of the turbine in the ocean temperature difference energy system is not adopted in the prior art.

Disclosure of Invention

In view of the above problems, the present invention provides an adaptive control system and method for turbine output power of an ocean temperature difference energy system, which can realize stable output of the turbine.

In order to achieve the purpose, the invention adopts the following technical scheme: a self-adaptive control system for turbine output power of an ocean temperature difference energy system is characterized by comprising a temperature sensor and a signal acquisition controller; the four temperature sensors are respectively arranged at the inlet and the outlet of the heat exchanger in the warm seawater loop and the cold seawater loop of the ocean temperature difference energy system and are used for measuring the inlet temperature and the outlet temperature of the heat exchanger in the warm seawater loop and the cold seawater loop in real time; the signal acquisition controller is respectively and electrically connected with the four temperature sensors and is used for calculating the flow velocity of the seawater required by stable output of the turbine in the ocean temperature difference energy system in real time according to the inlet temperature and the outlet temperature measured in real time by adopting a self-adaptive algorithm, and controlling the flow velocity of the seawater pump in the ocean temperature difference energy system in real time according to the calculated flow velocity of the seawater in real time so as to ensure that the turbine of the ocean temperature difference energy system reaches the working state of stable output.

Preferably, the sea water pump in the ocean temperature difference energy system comprises a warm sea water pump and a cold sea water pump, and a controllable flow pump with flow speed measurement and control is adopted.

Preferably, the heat exchanger in the warm seawater loop is an evaporator and the heat exchanger in the cold seawater loop is a condenser.

A self-adaptive control method for turbine output power of an ocean temperature difference energy system is characterized by comprising the following steps: 1) temperature sensors are respectively arranged at the inlet and the outlet of a heat exchanger in a warm seawater loop and a cold seawater loop of the ocean temperature difference energy system; 2) the four temperature sensors respectively measure the inlet temperature of the warm seawater of the heat exchanger, the outlet temperature of the warm seawater of the heat exchanger, the inlet temperature of the cold seawater of the heat exchanger and the outlet temperature of the cold seawater of the heat exchanger, and send the measured temperature data to the signal acquisition controller; 3) the signal acquisition controller adopts a self-adaptive algorithm, calculates the flow velocity of the seawater required by the stable output of the turbine in the ocean temperature difference energy system in real time according to the temperature data measured in real time, and controls the flow velocity of the seawater pump in the ocean temperature difference energy system in real time according to the flow velocity of the seawater calculated in real time, so that the turbine of the ocean temperature difference energy system reaches the working state of stable output.

Preferably, the adaptive algorithm in step 3) comprises the following steps: flow velocity V of warm seawater in warm seawater loop_wsInlet temperature of seawater according to temperature

The relationship of the changes satisfies the following formula:

wherein A is_EIs the heat exchange area, U, of a heat exchanger in a warm seawater loop_EIs the heat exchange coefficient of the heat exchanger in the warm seawater loop,

the specific heat of the warm seawater is used as the heat,

is the inlet temperature of the warm seawater,

outlet temperature for warm sea water, D_wsIs the pipe diameter, T, of the medium-temperature seawater pipe in the medium-temperature seawater loop_EThe evaporation temperature of the working medium;

when the temperature of the ocean warm sea water changes, according to the measured inlet temperature and outlet temperature of the warm sea water and the flow velocity V of the warm sea water in the warm sea water loop_wsInlet temperature of seawater according to temperature

The variable relation is used for adaptively adjusting the flow rate of the medium-temperature sea water pump in the ocean temperature difference energy system, so that the ocean temperature difference energy system is ensured to maintain constant evaporation temperature;

cold seawater flow velocity V_csInlet temperature of cold seawater

The relationship of the change satisfies the followingThe following formula:

wherein A is_CIs the heat exchange area, U, of a heat exchanger in a cold seawater loop_CThe heat exchange coefficient of the heat exchanger in the cold seawater loop,

the specific heat of the cold sea water is used,

is the inlet temperature of the cold seawater,

outlet temperature of cold sea water, D_csIs the pipe diameter, T, of the cold seawater pipe in the cold seawater loop_CThe working medium condensation temperature;

when the temperature of the cold seawater in the ocean changes, according to the measured inlet temperature and outlet temperature of the cold seawater and the flow velocity V of the cold seawater_csInlet temperature of cold seawater

The variable relation can adaptively adjust the flow rate of the cold sea water pump in the ocean temperature difference energy system, so that the ocean temperature difference energy system can maintain the constant condensation temperature, and further the output stability of turbine power in the ocean temperature difference energy system can be ensured.

Due to the adoption of the technical scheme, the invention has the following advantages: according to the temperature sensor, the temperature of the inlet and the outlet of the warm seawater and the cold seawater are measured in real time, and the self-adaptive algorithm is combined to ensure that the ocean temperature difference energy system can automatically adjust and control the flow velocity of the seawater in a self-adaptive manner along with the change of the temperature of the seawater, so that the heat exchange of the ocean temperature difference energy system is kept in the existing energy balance state, the turbine in the ocean temperature difference energy system is further ensured to reach the working state of stable output, the stability and the reliability of the operation of the system are improved, and the system can be widely applied to the field of ocean temperature difference energy power generation.

Drawings

FIG. 1 is a schematic diagram of a prior art Rankine cycle based ocean thermal energy system;

fig. 2 is a schematic structural diagram of the present invention.

Detailed Description

The present invention is described in detail below with reference to the attached drawings. It is to be understood, however, that the drawings are provided solely for the purposes of promoting an understanding of the invention and that they are not to be construed as limiting the invention.

As shown in fig. 1, an ocean temperature difference energy system in the prior art includes a turbine, a working medium pump, a warm seawater loop and a cold seawater loop, wherein the warm seawater loop includes an evaporator, a warm seawater pipe and a warm seawater pump, the cold seawater loop includes a condenser, a cold seawater pipe and a cold seawater loop, the turbine is used for converting energy contained in a fluid working medium into mechanical work, the working medium pump is used for driving the working medium to flow in a thermodynamic cycle system, the evaporator is used for exchanging heat between the warm seawater and the working medium so as to heat the working medium to an evaporation temperature, the warm seawater pump is used for sending the warm seawater as a heat source to the evaporator so as to heat the working medium, the condenser is used for exchanging heat between the cold seawater and the working medium so as to condense the working medium to a condensation temperature, and the cold seawater pump is used for sending the cold seawater as a cold source to the condenser so as to condense the working medium.

Based on the above explanation, as shown in fig. 2, the adaptive control system for turbine output power of an ocean thermal difference energy system provided by the invention comprises a temperature sensor 1 and a signal acquisition controller 2.

The four temperature sensors 1 are respectively arranged at the inlet and the outlet of a heat exchanger (the warm sea water loop corresponds to an evaporator, and the cold sea water loop corresponds to a condenser) in the warm sea water loop and the cold sea water loop of the ocean temperature difference energy system, and are used for measuring the inlet temperature and the outlet temperature of the heat exchanger in the warm sea water loop and the cold sea water loop in real time.

The four temperature sensors 1 are respectively and electrically connected with the signal acquisition controller 2, the signal acquisition controller 2 adopts a self-adaptive algorithm, the seawater flow rate required by the stable output of the turbine in the ocean temperature difference energy system (namely the output power of the turbine keeps relatively constant) is calculated in real time according to the inlet temperature and the outlet temperature measured by the temperature sensors 1 in real time, the flow rate of the seawater pump in the ocean temperature difference energy system is controlled in real time according to the seawater flow rate calculated in real time, the heat exchanger is kept in the existing energy balance state, and therefore the turbine in the ocean temperature difference energy system is ensured to achieve the working state of stable output.

In a preferred embodiment, both the warm sea water pump and the cold sea water pump in the ocean thermal energy system use controllable flow pumps with flow rate measurement and control.

Based on the ocean temperature difference energy system turbine output power self-adaptive control system, the invention also provides a ocean temperature difference energy system turbine output power self-adaptive control system method, which comprises the following steps:

1) temperature sensors 1 are installed at the inlet and outlet of the evaporator and condenser, respectively, in the ocean thermal energy system.

2) When the temperature of the seawater changes, the four temperature sensors 1 respectively measure the inlet temperature of the evaporator warm seawater, the outlet temperature of the evaporator warm seawater, the inlet temperature of the condenser cold seawater and the outlet temperature of the condenser cold seawater, and send the temperature data to the signal acquisition controller 2.

3) The signal acquisition controller 2 calculates the flow speed of seawater required by the stable output of the turbine in the ocean temperature difference energy system according to the real-time measured temperature data by adopting a self-adaptive algorithm, and outputs a signal to control the flow speed of a seawater pump so as to keep the heat exchanger in the existing energy balance state, thereby ensuring that the turbine in the ocean temperature difference energy system reaches the working state of stable output.

The control process of the adaptive algorithm in the step 3) is as follows:

3.1) according to the energy conservation and heat transfer law of the heat exchanger, the energy balance of the evaporator in the ocean temperature difference energy system can be determined by the following formula:

wherein Q is_EIs the medium temperature seawater and working medium of an evaporatorHeat exchange rate of (A)_EIs the heat exchange area of the evaporator, U_EIn order to be the heat exchange coefficient of the evaporator,

the flow rate of the warm seawater is adopted,

the specific heat of the warm seawater is used as the heat,

is the inlet temperature of the warm seawater of the evaporator,

the outlet temperature of the warm seawater of the evaporator, (. DELTA.T)_m)_EIs the logarithmic temperature difference of the evaporator, and:

wherein, T_EIs the evaporation temperature of the working medium.

According to the formula (1) and the formula (2), the flow rate of the warm seawater can be obtained

3.2) setting the pipe diameter of the medium-temperature seawater pipe in the medium-temperature seawater pipe to be D_wsAnd the flow velocity V of warm seawater in the warm seawater loop_wsComprises the following steps:

the above formula (4) gives the velocity V of warm seawater_wsInlet temperature of seawater as evaporator temperature

Of variationAnd (4) relationship.

3.3) when the temperature of the ocean moderate-temperature seawater changes, the measured temperature value of the warm-seawater inlet is adaptively adjusted according to the formula (4) to ensure that the ocean temperature difference energy system maintains constant evaporation temperature.

3.4) same principle, cold seawater flow velocity V_csInlet temperature of cold seawater with condenser

The relationship of the changes satisfies the following equation:

wherein A is_CIs the heat exchange area of the condenser, U_CIn order to be the heat exchange coefficient of the condenser,

the specific heat of the cold sea water is used,is the inlet temperature of the cold seawater of the condenser,

outlet temperature of cold seawater for condenser, D_csIs the pipe diameter, T, of the cold seawater pipe in the cold seawater pipeline_CIs the working medium condensation temperature.

3.5) when the temperature of the cold seawater in the ocean changes, the measured temperature value of the inlet of the cold seawater is adaptively adjusted according to the formula (5) to ensure that the condensing temperature of the ocean temperature difference energy system is kept constant, further ensure that the output of the turbine power in the ocean temperature difference energy system is stable, and realize the adaptive control of the turbine output power of the ocean temperature difference energy system facing the temperature change of the seawater.

In general, the temperature of cold seawater is basically unchanged and can be regarded as constant, so that the temperature of warm seawater can be adapted to the temperature change of warm seawater by adjusting the flow rate of the warm seawater pump, and the power output of a turbine in the ocean temperature difference energy system is stable.

The above embodiments are only used for illustrating the present invention, and the structure, connection mode, manufacturing process, etc. of the components may be changed, and all equivalent changes and modifications performed on the basis of the technical solution of the present invention should not be excluded from the protection scope of the present invention.