CN-122014482-A - Sea Liu Xietong type sea water pumped storage-ocean temperature difference heat energy composite power generation system and method

CN122014482ACN 122014482 ACN122014482 ACN 122014482ACN-122014482-A

Abstract

The invention provides a sea Liu Xietong type sea water pumped storage-ocean temperature difference heat energy composite power generation system and a method, and aims to solve the problems of low energy utilization rate, poor stability and high cost caused by independent operation of sea water pumped storage and OTEC. The system comprises a seawater pumped storage subsystem, an OTEC subsystem, a cooperative control subsystem and a heat energy recovery module, realizes three-way reversible conversion of electricity, potential energy and heat energy through a three-in-one architecture, dynamically switches energy conversion paths based on power grid loads (low valley period, peak period and flat period), stores surplus power through a dual-path in the low valley period, cooperatively supplies power in the peak period and optimizes energy consumption in the flat period. The invention improves the ocean energy utilization efficiency and the power grid stability, reduces the construction and operation costs, and has obvious economic and environmental benefits.

Inventors

MA YONGJIE
WANG JINGYONG
TIAN ZHAO

Assignees

中国电建集团华东勘测设计研究院有限公司
浙江华东岩土勘察设计研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20260120

Claims (6)

1. A seawater pumping energy storage-ocean temperature difference heat energy composite power generation system of the sea Liu Xietong is characterized by comprising a seawater pumping energy storage subsystem, an OTEC subsystem, a cooperative control subsystem and a heat energy recovery module, The seawater pumped storage subsystem comprises a coastal high-level reservoir, a pump set, a hydroelectric generating set, a water pipeline and a water level monitoring module, wherein the water pipeline comprises a water pumping pipeline and a water discharging pipeline, one end of the water pumping pipeline is connected with an offshore water intake, the other end of the water pumping pipeline extends to the bottom of the coastal high-level reservoir, one end of the water discharging pipeline is connected with the bottom of the coastal high-level reservoir, and the other end of the water discharging pipeline extends to an offshore water outlet; The OTEC subsystem comprises a surface-layer warm water intake device, a deep-layer cold water intake device, an evaporator, a condenser, a low-boiling-point working medium circulation loop, a heat engine generator set and a temperature monitoring module, wherein the input end of the evaporator is connected with the surface-layer warm water intake device through a pipeline, the output end of the evaporator is connected with the condenser through a pipeline, the input end of the condenser is connected with the deep-layer cold water intake device through a pipeline, the output end of the condenser is connected with the low-boiling-point working medium circulation loop through a pipeline, and the heat engine generator set is connected in series with the low-boiling-point working medium circulation loop; The cooperative control subsystem comprises a power grid load sensor, a seawater temperature sensor, a reservoir water level sensor, a working medium pressure sensor, a central controller and an electric energy distribution module, wherein the central controller receives signals of the sensors and outputs control instructions to the pumping pump set, the hydroelectric generating set and auxiliary equipment of the OTEC subsystem through a preset algorithm, and the electric energy distribution module realizes electric energy circulation control among the power grid, the seawater pumping energy storage subsystem and the OTEC subsystem through an electric control element; the heat energy recovery module is arranged between a water drain pipeline of the seawater pumped storage subsystem and an evaporator of the OTEC subsystem, a sleeve-type heat exchanger is adopted, an inner pipe is a water drain pipeline, and an outer pipe is a working medium circulation channel.
2. The marine Liu Xietong type seawater pumped storage-ocean temperature difference heat energy composite power generation system according to claim 1 is characterized in that the surface-layer warm water intake device is arranged in a shallow water area below the sea level and is provided with a filter screen for preventing marine organism blockage.
3. The seawater Liu Xietong pumped storage-ocean temperature difference heat energy composite power generation system as claimed in claim 1, wherein the deep cold water intake device is arranged in a deep water area below the sea level and adopts a corrosion-resistant alloy pipeline.
4. The marine Liu Xietong type seawater pumped storage-ocean temperature difference heat energy composite power generation system according to claim 1 is characterized in that the low-boiling point working medium circulation loop is filled with a fluorochloroalkane working medium.
5. The marine Liu Xietong type seawater pumped storage-ocean temperature difference heat energy composite power generation system according to claim 1, wherein the central controller adopts a PLC control system and has quick response capability.
6. A sea Liu Xietong type sea water pumped storage-ocean temperature difference heat energy composite power generation method is characterized in that the method is based on the system as set forth in any one of claims 1-5 and comprises the following steps: During the off-peak period of the power grid load, pumping off-shore seawater to the coastal high-level reservoir through a pumping set to store potential energy, or lifting the evaporation temperature of a low-boiling-point working medium through auxiliary equipment of an OTEC subsystem, storing heat energy in a low-boiling-point working medium circulation loop, or assisting in seawater pumping through electric energy generated by power generation of the OTEC subsystem; In the peak period of power grid load, the water in the coastal high-level reservoir is discharged to drive the hydroelectric generating set to generate power, meanwhile, the OTEC subsystem is used for generating power by utilizing the temperature difference between the surface-layer warm water and the deep-layer cold water, and if the surface-layer water temperature is reduced, the heat energy recovery module is used for heating the working medium by utilizing the waste heat of the discharged water, so that the power generation of the OTEC subsystem is improved; And in the power grid load leveling section, the OTEC subsystem maintains partial power operation, the seawater pumping and energy storage subsystem maintains the reservoir water level in an intermittent pumping mode, and meanwhile, warm water drainage of the OTEC subsystem is conveyed to an offshore water intake to preheat seawater to be pumped.

Description

Sea Liu Xietong type sea water pumped storage-ocean temperature difference heat energy composite power generation system and method Technical Field The invention belongs to the technical field of new energy utilization and electric energy storage, and particularly relates to a sea Liu Xietong type seawater pumped storage (Seawater Pumped Hydro Storage, SPHS) -Ocean temperature difference heat energy (Ocean THERMAL ENERGY Conversion, OTEC) composite power generation system and method. Background With the rapid development of renewable energy sources, grid peaking and energy storage become key challenges. In the prior art, seawater pumped storage utilizes seawater as a working medium, pumps water to a high-place reservoir or a deep-sea energy storage unit when the load of a power grid is low, and discharges water to generate electricity when the load is high, so that electric energy-potential energy conversion is realized. However, this technique is terrain limited and efficiency is greatly affected by water head differences. On the other hand, the Ocean Thermal Energy Conversion (OTEC) technology utilizes the temperature difference between surface-layer warm water (about 26-28 ℃) and deep-layer cold water (about 4-6 ℃), and generates electricity through the evaporation-condensation cycle of a low-boiling-point working medium (such as fluorochloromethane), but the electricity generation efficiency is lower, and is influenced by ocean environment fluctuation, so that the demand of a power grid is difficult to independently meet. At present, no mature technology has been available to organically combine seawater pumped storage with OTEC to overcome the respective drawbacks. The existing system operates independently, so that the energy utilization rate is low, and the infrastructure is redundant. Therefore, an integration scheme is needed to realize the cooperative conversion and storage of various energy forms, and improve the overall efficiency and the power grid adaptability. Disclosure of Invention The first aim of the invention is to provide a sea Liu Xietong type sea water pumped storage-ocean temperature difference heat energy composite power generation system aiming at the problems. In order to achieve the above purpose, the invention adopts the following technical scheme: a seawater Liu Xietong pumped storage-ocean temperature difference heat energy composite power generation system comprises a seawater pumped storage subsystem, an OTEC subsystem, a cooperative control subsystem and a heat energy recovery module, The seawater pumped storage subsystem comprises a coastal high-level reservoir, a pump set, a hydroelectric generating set, a water pipeline and a water level monitoring module, wherein the water pipeline comprises a water pumping pipeline and a water discharging pipeline, one end of the water pumping pipeline is connected with an offshore water intake, the other end of the water pumping pipeline extends to the bottom of the coastal high-level reservoir, one end of the water discharging pipeline is connected with the bottom of the coastal high-level reservoir, and the other end of the water discharging pipeline extends to an offshore water outlet; The OTEC subsystem comprises a surface-layer warm water intake device, a deep-layer cold water intake device, an evaporator, a condenser, a low-boiling-point working medium circulation loop, a heat engine generator set and a temperature monitoring module, wherein the input end of the evaporator is connected with the surface-layer warm water intake device through a pipeline, the output end of the evaporator is connected with the condenser through a pipeline, the input end of the condenser is connected with the deep-layer cold water intake device through a pipeline, the output end of the condenser is connected with the low-boiling-point working medium circulation loop through a pipeline, and the heat engine generator set is connected in series with the low-boiling-point working medium circulation loop; The cooperative control subsystem comprises a power grid load sensor, a seawater temperature sensor, a reservoir water level sensor, a working medium pressure sensor, a central controller and an electric energy distribution module, wherein the central controller receives signals of the sensors and outputs control instructions to the pumping pump set, the hydroelectric generating set and auxiliary equipment of the OTEC subsystem through a preset algorithm, and the electric energy distribution module realizes electric energy circulation control among the power grid, the seawater pumping energy storage subsystem and the OTEC subsystem through an electric control element; the heat energy recovery module is arranged between a water drain pipeline of the seawater pumped storage subsystem and an evaporator of the OTEC subsystem, a sleeve-type heat exchanger is adopted, an inner pipe is a water drain pipeline, and an outer pipe is a working medium circulation ch