CN-121990637-A - Solar distillation sea water desalination system with multiple heat sources for district heating

Abstract

The invention relates to the technical field of sea water desalination, and discloses a solar distilled sea water desalination system with multiple heat sources for district heating, which integrates a gas engine heat pump unit, a solar distillation unit and an optional salt difference energy utilization interface unit. The heat pump condenser exchanges heat with the upper middle region of the distiller to stably heat the water body of the evaporation interface, so that different heat source zone heating modes are formed. Fresh water and concentrated solution produced by distillation are collected separately. The salt difference energy utilization device is connected with the salt difference energy utilization interface unit when energy is required to be recovered. The system realizes multi-heat source cascade utilization, improves distillation efficiency and operation stability, and can recycle salt difference energy as required.

Inventors

• DONG FUJIANG
• HUA YUDONG
• SHEN XINYU
• Sun Cunzhe
• Li Xiuzhe

Assignees

• 烟台大学

Dates

Publication Date

20260508

Application Date

20260323

Claims (9)

1. 1. A solar distillation seawater desalination system with multiple heat sources for district heating, comprising: The gas engine heat pump unit comprises a compressor, a condenser, an evaporator and a gas engine, wherein the compressor, the condenser and the evaporator are connected with each other, and the gas engine is connected with the compressor; the solar distillation unit comprises a solar distiller, a fresh water pipeline, a fresh water storage tank and a distillate storage tank; the waste heat recovery and lower heat supply unit is used for introducing cylinder sleeve water waste heat and/or smoke waste heat generated in the operation process of the gas engine into a lower distillation area of the solar distiller to preheat seawater entering the solar distiller; The upper heat supply unit of the condenser is arranged to exchange heat with the middle or upper distillation area of the solar distiller and is used for stably heating the water body near the evaporation interface; The salt difference energy utilization interface unit is communicated with the distillate storage tank and the seawater supply unit and is used for being connected with a salt difference energy utilization device when energy recovery is needed; The waste heat recovery and lower heat supply unit and the upper heat supply unit of the condenser respectively act on different distillation areas of the solar distiller, wherein the lower distillation area is used for preheating seawater, and the upper distillation area is used for heating an evaporation interface.
2. 2. The multiple heat source district heating solar distillation seawater desalination system of claim 1, wherein the gas turbine heat pump unit further comprises a throttle valve, wherein the condenser comprises a condensing refrigerant line, and wherein the evaporator comprises an evaporating refrigerant line; The compressor outlet is connected with the condensed refrigerant pipeline inlet, the condensed refrigerant pipeline outlet is connected with the evaporated refrigerant pipeline inlet, the evaporated refrigerant pipeline outlet is connected with the compressor, and the throttle valve is arranged between the condensed refrigerant pipeline and the evaporated refrigerant pipeline.
3. 3. The solar-powered, district heating, distillation seawater desalination system of claim 2 wherein the waste heat recovery and lower heating unit comprises a cylinder water heat exchanger and a flue gas heat exchanger, heat exchange outlets of the cylinder water heat exchanger and the flue gas heat exchanger being in communication with the lower distillation zone of the solar still, the cylinder water heat exchanger comprising an inner cylinder jacket and an outer cylinder jacket, the flue gas heat exchanger comprising a flue gas duct and a flue gas heat exchange shell; The heat exchange outlet of the gas engine is connected with the inlet of the inner cylinder sleeve, the inlet of the outer cylinder sleeve is connected with the outlet of the heat exchange water storage tank, and the outlet of the outer cylinder sleeve is connected with the inlet of the flue gas heat exchange shell; the gas engine is characterized in that a gas outlet of the gas engine is connected with a gas pipeline inlet, and the gas pipeline outlet is connected with the outside.
4. 4. A multi-heat source district heating solar distillation seawater desalination system according to claim 3 wherein the evaporating refrigerant conduit is disposed within the solar still and above the fresh water conduit, the condenser is configured to exchange heat with an upper middle water region of the solar still, the upper middle water region being located at an evaporation interface of the solar still.
5. 5. The solar distilled seawater desalination system of multi-heat source district heating according to claim 4, wherein the solar distiller is connected with the evaporator, the fresh water pipeline is arranged in the middle of the solar distiller, the fresh water storage tank is connected with the fresh water pipeline, the heat exchanger is arranged at the bottom of the solar distiller, the heat exchanger is used for heating and evaporating seawater in the solar distiller, and the distillate storage tank is connected with the solar distiller.
6. 6. The solar-powered, zoned-heated, distilled seawater desalination system of claim 5, wherein the solar-powered distillation unit comprises a heat-exchange water storage tank and a cooling water pump, wherein the heat-exchange water storage tank outlet is connected to the heat-exchange water storage tank inlet, the heat-exchange water storage tank outlet is connected to the cooling water pump inlet, and the cooling water pump outlet is connected to the outer cylinder sleeve inlet.
7. 7. The solar-powered, zoned-heated, solar-powered, distilled seawater desalination system of claim 6, wherein the concentrated solution outlet of the solar distiller is connected to the distillate storage tank, and wherein the distillate storage tank is connected to the concentrated solution inlet of the salt-differential energy utilization interface unit via a distillate pump.
8. 8. The solar-powered, zoned-heating, distilled seawater desalination system of claim 7, wherein the salt-differential energy utilization device connected by the salt-differential energy utilization interface unit is a reverse electrodialysis power generation device, the salt-differential energy utilization interface unit further comprises a load, a waste liquid storage tank and a waste liquid pump, the load is connected with the reverse electrodialysis power generation device, the waste liquid storage tank inlet is connected with a waste liquid outlet of the reverse electrodialysis power generation device, an outlet of the waste liquid storage tank is connected with the waste liquid pump, and the waste liquid pump is connected with the solar distiller inlet.
9. 9. The multiple heat source district heating solar distillation seawater desalination system of claim 8, wherein the seawater supply unit comprises a seawater storage tank, wherein the seawater storage tank outlet is connected to a seawater pump inlet, wherein the seawater pump outlet is connected to a solar still inlet, and wherein the seawater pump outlet is further connected to a fresh water inlet of a reverse electrodialysis power generation device.

Description

Solar distillation sea water desalination system with multiple heat sources for district heating Technical Field The invention relates to the technical field of sea water desalination, in particular to a solar distillation sea water desalination system with multiple heat sources for district heating. Background At present, water resources are increasingly scarce and unevenly distributed, sea water desalination is one of key technologies for solving the shortage problem of the sea water desalination, the traditional distillation method (such as multi-stage flash evaporation and multi-effect distillation) has higher energy consumption, and the reverse osmosis method has the problems of membrane pollution, high pressure requirement and the like although the efficiency is improved. Solar distillation is used as a low-carbon environment-friendly sea water desalination mode, has the advantages of simple structure, low operation and maintenance cost and the like, but the water production efficiency is greatly influenced by weather conditions, the water yield per unit area is limited, and the large-scale fresh water requirement is difficult to meet. To increase the efficiency of solar distillation, researchers often combine it with an auxiliary heat source, such as a heat pump system, to increase the evaporation temperature and speed up the water-vapor separation process. However, the heat pump system consumes secondary energy, i.e. electricity, and has higher energy storage and user energy costs compared with primary energy. Meanwhile, the strong brine generated in the sea water desalination process and the desalted fresh water have obvious salinity difference, and ideal conditions are provided for Reverse Electrodialysis (RED) power generation. The RED system is coupled with the sea water desalination process, so that the cascade utilization of energy sources can be realized, and the comprehensive utilization efficiency of the system energy sources is further improved. Under the background of severe energy safety and climate challenges, how to improve the comprehensive utilization efficiency of energy and reduce the consumption of fossil energy has become a key subject for energy transformation in various countries. Although the conventional power system represented by the gas engine is widely applied in the fields of industry, power generation and the like, the energy utilization efficiency of the conventional power system still has a larger improvement space. Research data shows that about 35-40% of energy of the gas engine is converted into effective power output, and more than 50% of energy is dissipated in the form of cylinder liner water waste heat and high-temperature smoke, so that the problems of obvious energy waste and heat pollution are caused. If the waste heat can be effectively recovered, a stable auxiliary heat source can be provided for the sea water desalination process, so that the overall energy efficiency of the system is improved. More importantly, the existing gas engine system is single in function, generally takes output mechanical work or electric energy as a main target, lacks cooperative optimization of multiple energy forms such as fuel chemical energy, waste heat, environmental energy and the like, cannot construct a clean and efficient coupling system, and is difficult to adapt to the technical requirements of future energy systems. Therefore, a need exists for a solar-powered distilled seawater desalination system capable of achieving multi-heat source zoned heating. Disclosure of Invention The invention aims to provide a solar distillation sea water desalination system with multiple heat sources for district heating, which aims to realize energy cascade utilization in the sea water desalination process, recover electric energy, improve the energy utilization efficiency and operation stability of the system and realize further utilization of salt energy when needed by respectively applying different heat sources to different distillation areas of a distiller. The invention provides a solar distillation sea water desalination system with multiple heat sources for district heating, which comprises: The gas engine heat pump unit comprises a compressor, a condenser, an evaporator and a gas engine, wherein the compressor, the condenser and the evaporator are connected with each other, and the gas engine is connected with the compressor; the solar distillation unit comprises a solar distiller, a fresh water pipeline, a fresh water storage tank and a distillate storage tank; the waste heat recovery and lower heat supply unit is used for introducing cylinder sleeve water waste heat and/or smoke waste heat generated in the operation process of the gas engine into a lower distillation area of the solar distiller to preheat seawater entering the solar distiller 11; The upper heat supply unit of the condenser is arranged to exchange heat with the middle or upper distillation area of the solar