CN214880331U - Novel low-temperature exhaust-heat seawater desalination system - Google Patents

Abstract

The utility model relates to the technical field of recovering exhausted heat for desalinating seawater, in particular to a novel low-temperature exhausted heat seawater desalinating system.A unit for generating low-temperature exhausted heat is sequentially connected with a plurality of coolers and an exhausted heat inlet of an evaporator, a refrigerant outlet of the evaporator is sequentially connected with a compressor, a tube pass of a first-effect heat exchange tube of a low-temperature multi-effect distillation device, a throttling device and a refrigerant inlet of the evaporator, and an exhausted heat outlet of the evaporator is sequentially connected with a cooling water pump and a cooler inlet; the shell pass inlet of the effective heat exchange tube is connected with the spraying device, the shell pass outlet of the previous effective heat exchange tube is connected with the tube pass inlet of the next effective heat exchange tube, the last effective shell pass outlet is connected with the shell side inlet of the condenser, and the tube pass outlets of the other effective heat exchange tubes outside the first effect and the shell side outlet of the condenser are connected with the distilled water collecting device. Compared with the prior art, the utility model, utilize the refrigerant to draw low-grade exhaust heat, be used for evaporating the sea water after heating up, reduce fresh water production's energy consumption, make the water ratio and can reach 8 ~ 12.

Description

Novel low-temperature exhaust-heat seawater desalination system

Technical Field

The utility model belongs to the technical field of retrieve the hot desalination sea water of exhaustion and specifically relates to a novel low temperature hot desalination sea water system of exhaustion.

Background

At present, in thermodynamic systems of nuclear power plants, thermal power plants and the like in the world, Rankine cycle with steam as a working medium is generally adopted, generally, the cycle efficiency of a supercritical thermal power generating unit is about 45%, and the cycle efficiency of a large nuclear power generating unit is generally about 35% of that of saturated steam. In the world, the vast majority of electricity is converted from heat, for example: the heat that boiler, nuclear reactor, light and heat, living beings etc. produced, more than 60% heat becomes the weary heat, has discharged the environment through warm water drainage etc. and most weary heat have all become the pollution sources of water body thermal pollution, and this has led to the rising of earth's surface water temperature, reduces water dissolved oxygen and aggravate water body pollution, leads to the community of algae biology to replace for aquatic organisms's biochemical reaction speed destroys fish living environment, endangers the human health. Some hazardous events of thermal contamination have occurred in the world. The investigation result of the biostimization event of the heat pollution in the Bay of the Bessan caused by the nuclear power plant in the United states shows that almost all animals and plants are extinct in water areas with the water temperature rising above 4 ℃, common diatom, red algae and brown algae disappear, and instead, high-temperature blue-green algae breed in large quantity.

The reason for causing above-mentioned problem exists is that a large amount of exhaust heat is not fully utilized, because the exhaust heat temperature is low, the traditional view considers that the exhaust heat (for fire) value is low and has no utilization value, and the prior art has no way to fully recycle the low temperature exhaust heat, thereby causing a large amount of low grade heat to run off, not only causing energy loss, but also producing a large amount of thermal pollution.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the defects of the prior art, providing a novel seawater desalination system which utilizes low-temperature exhaust heat of a nuclear power plant, a thermal power plant, a biomass power plant and the like, converting the low-grade exhaust heat into high-grade heat by utilizing high-grade energy, and performing seawater desalination as a heat source of a low-temperature multi-effect distillation device, thereby improving the energy utilization rate and the economy of the whole society, reducing thermal pollution, reducing the fresh water making cost and canceling a final heat trap circulating water system which discharges waste heat in the traditional thermodynamic system; the method can also be expanded to other low-temperature waste heat fields, and the low-temperature waste heat is utilized to produce distilled water through river water, lake water, underground water and the like.

In order to realize the aim, a novel low-temperature exhaust-heat seawater desalination system is designed, which is characterized in that,

the system comprises a unit for generating low-temperature exhaust heat, a plurality of coolers, a cooling water pump, an evaporator, a compressor, a throttling device, a low-temperature multi-effect distillation device and a condenser;

the waste heat outlet of the unit for generating low-temperature waste heat is divided into multiple paths and is respectively connected with the hot side inlets of the coolers, the cooling water outlets of the coolers are connected with the waste heat inlet of the evaporator after being gathered, the refrigerant outlet of the evaporator is connected with the refrigerant inlet of the compressor, the refrigerant outlet of the compressor is connected with the tube side inlet of the first-effect heat exchange tube of the low-temperature multi-effect distillation device, the tube side outlet of the first-effect heat exchange tube is sequentially connected with the throttling device and the refrigerant inlet of the evaporator, the waste heat outlet of the evaporator is connected with the inlet of the cooling water pump, and the outlet of the cooling water pump is connected with the cooling water inlets of the coolers; the shell side inlets of all the effect heat exchange tubes of the low-temperature multi-effect distillation device are respectively connected with a spraying device, the shell side outlet of the previous effect heat exchange tube is connected with the tube side inlet of the next effect heat exchange tube, the last effect shell side outlet is connected with the shell side inlet of the condenser, and the tube side outlets of the other effect heat exchange tubes except the first effect heat exchange tube of the low-temperature multi-effect distillation device and the shell side outlet of the condenser are respectively connected with a distilled water collecting device.

Furthermore, the unit for generating low-temperature exhaust heat comprises a nuclear power plant, a thermal power plant and a biomass power plant.

Compared with the prior art, the utility model, after the low-grade exhaust heat in the power plant is heated by the refrigerant, the refrigerant is transmitted to the low-temperature multi-effect distillation seawater desalination device for the first effect, the energy efficiency ratio of the evaporator and the compressor can reach 5-8, the economy and the energy-saving effect are quite good, and the discharge of warm water to the environment is reduced; the first effect seawater in the low-temperature multi-effect distillation device is heated and evaporated by a refrigerant, the highest temperature of the seawater is not more than 70 ℃, the secondary steam generated by evaporation is used as heating steam to heat the next effect seawater, and the rest is continued, so that the heat energy consumed by evaporation is fully recycled, the energy consumption is reduced, and the water generation ratio can reach 8-12.

Drawings

Fig. 1 is a schematic flow chart of the present invention.

Detailed Description

The present invention will now be further described with reference to the accompanying drawings.

Example 1

Referring to fig. 1, a novel low-temperature exhaust-heat seawater desalination system is characterized in that,

the system comprises a unit 1 for generating low-temperature exhaust heat, a plurality of coolers 2, a cooling water pump 3, an evaporator 4, a compressor 5, a throttling device 6, a low-temperature multi-effect distillation device 7 and a condenser 8;

the waste heat outlet of the unit 1 for generating low-temperature waste heat is divided into multiple paths and is respectively connected with hot side inlets of the coolers 2, cooling water outlets of the coolers 2 are connected with the waste heat inlet of the evaporator 4 after being gathered, a refrigerant outlet of the evaporator 4 is connected with a refrigerant inlet of the compressor 5, a refrigerant outlet of the compressor 5 is connected with a tube pass inlet of a first-effect heat exchange tube of the low-temperature multi-effect distillation device 7, the tube pass outlet of the first-effect heat exchange tube is sequentially connected with a throttling device 6 and the refrigerant inlet of the evaporator 4, the waste heat outlet of the evaporator 4 is connected with an inlet of the cooling water pump 3, and an outlet of the cooling water pump 3 is connected with the cooling water inlets of the coolers 2; the shell side inlets of all the effect heat exchange tubes of the low-temperature multi-effect distillation device 7 are respectively connected with a spraying device, the shell side outlet of the previous effect heat exchange tube is connected with the tube side inlet of the next effect heat exchange tube, the last effect shell side outlet is connected with the shell side inlet of the condenser 8, and the tube side outlets of the other effect heat exchange tubes except the first effect heat exchange tube of the low-temperature multi-effect distillation device 7 and the shell side outlet of the condenser 8 are respectively connected with a distilled water collecting device.

The unit 1 for generating low-temperature waste heat comprises nuclear power, thermal power, steel, chemical engineering, photo-thermal, biomass and other occasions with low-temperature waste heat.

When the low-temperature spent heat source is close to the ocean, the seawater for spraying in the spraying device is used; if the low-temperature heat-lack source is far away from the ocean, other cooling water sources are used as the feed water to produce the distilled water. The working method is described by taking seawater as an example:

a novel method of a low-temperature spent heat seawater desalination system is characterized in that spent heat coming out of a unit 1 generating low-temperature spent heat enters each cooler 2 for cooling; cooling water of 40-50 ℃ from the cooler 2 enters the evaporator 4 and is cooled into water of 20-30 ℃; water with the temperature of 20-30 ℃ is circularly supplied to each cooler 2 through a cooling water pump 3;

the refrigerant absorbs the waste heat of the cooling water of the unit 1 generating low-temperature waste heat in the evaporator 4, then the refrigerant is continuously gasified and is pressurized by the compressor 5 to become a saturated gaseous refrigerant at the temperature of 60-80 ℃; high-temperature and high-pressure gaseous refrigerant enters a first-effect heat exchange tube of the low-temperature multi-effect distillation device 7 to heat seawater from a spraying device outside the evaporation tube, the highest evaporation temperature of the seawater is less than 70 ℃, secondary steam generated by evaporation is used as heating steam in a next-effect heat exchange tube to heat the seawater outside the tube, the rest of the effect heat exchange tubes except the first-effect heat exchange tube of the low-temperature multi-effect distillation device 7 are cooled by seawater in a condenser 8, and distilled water obtained by condensation in tube passes of the other effect heat exchange tubes except the first-effect heat exchange tube of the low-temperature multi-effect distillation device 7 is respectively connected with a distilled water collecting device; the refrigerant is condensed into high-pressure liquid in a first-effect heat exchange pipe of the low-temperature multi-effect distillation device 7, the high-pressure liquid is decompressed into low-pressure liquid through the throttling device 6, and the refrigerant in the low-pressure liquid state absorbs low-temperature exhaust heat in the evaporator 4 and is continuously gasified; finally, the gasified refrigerant in the evaporator 4 is changed into low-pressure gas, and the low-pressure gas enters the compressor 5 again, and the circulation is repeated in such a way, so that low-grade waste heat is extracted from the unit 1 generating low-temperature waste heat for seawater desalination. The refrigerant comprises Freon, ammonia or water.

Therefore, the energy utilization rate and the economical efficiency of a nuclear power plant/a thermal power plant and the like are improved, the thermal pollution is reduced, the water making cost is reduced, and a final heat trap circulating water system for discharging waste heat in a traditional thermodynamic system is eliminated. If the low-temperature spent heat source is far away from the ocean, other cooling water sources are used as material water to produce distilled water, and the effect of recycling the low-temperature spent heat is achieved.

Claims (2)

1. A novel low-temperature exhaust-heat seawater desalination system, which is characterized in that,

the system comprises a unit (1) for generating low-temperature exhaust heat, a plurality of coolers (2), a cooling water pump (3), an evaporator (4), a compressor (5), a throttling device (6), a low-temperature multi-effect distillation device (7) and a condenser (8);

the waste heat outlet of the unit (1) for generating low-temperature waste heat is divided into multiple paths and is respectively connected with hot side inlets of the coolers (2), cooling water outlets of the coolers (2) are connected with the waste heat inlet of the evaporator (4) after being gathered, a refrigerant outlet of the evaporator (4) is connected with a refrigerant inlet of the compressor (5), a refrigerant outlet of the compressor (5) is connected with a tube pass inlet of a first-effect heat exchange tube of the low-temperature multi-effect distillation device (7), the tube pass outlet of the first-effect heat exchange tube is sequentially connected with the throttling device (6) and the refrigerant inlet of the evaporator (4), the waste heat outlet of the evaporator (4) is connected with an inlet of the cooling water pump (3), and an outlet of the cooling water pump (3) is connected with cooling water inlets of the coolers (2); the shell side inlets of all the effect heat exchange tubes of the low-temperature multi-effect distillation device (7) are respectively connected with a spraying device, the shell side outlet of the previous effect heat exchange tube is connected with the tube side inlet of the next effect heat exchange tube, the last effect shell side outlet is connected with the shell side inlet of the condenser (8), and the tube side outlets of the other effect heat exchange tubes except the first effect heat exchange tube of the low-temperature multi-effect distillation device (7) and the shell side outlet of the condenser (8) are respectively connected with a distilled water collecting device.

2. A novel low-temperature spent heat seawater desalination system as defined in claim 1, wherein the unit (1) for generating low-temperature spent heat comprises a nuclear power plant, a thermal power plant and a biomass power plant.

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