Multi-stage seawater desalination and lithium bromide unit refrigeration / heating system

Abstract

The utility model discloses a multi-stage sea water desalination and lithium bromide unit refrigeration / heating system which is composed of a generator, a first condenser, a first evaporator, an absorber, a refrigerant pump, a solution pump, a heat exchanger, a valve, a second evaporator, a third evaporator, a filter, a diaphragm valve, a shield pump, a second condenser, a third condenser and a liquid baffle. The seawater is divided into two parts, the first part enters the second evaporator for multi-stage desalination, and the other part serves as a cooling water auxiliary system for refrigeration and heating; according to the utility model, waste heat in a ship is fully utilized, the energy utilization rate is improved, refrigeration and seawater desalination are matched, the total amount of fresh water is increased, the requirements of refrigeration and heating are met, and the pollution of a refrigerant to the environment is reduced.

Description

Technical Field

[0001] This utility model relates to the field of waste heat utilization and seawater desalination technology, and in particular to multi-stage seawater desalination and lithium bromide refrigeration / heating systems. Background Technology

[0002] In the marine industry, traditional refrigeration methods utilize Freon as a refrigerant and electricity as the driving force for cooling and heating at the terminal. Freon is widely used due to its economy and thermal stability. However, with global warming, the excessive use of Freon as a refrigerant will cause environmental pollution, increase ozone depletion potential and global warming potential. 50% of the heat generated by diesel generators in ships is not fully utilized. Using electricity as the driving force not only increases the ship's electrical load but also reduces energy efficiency.

[0003] Seawater desalination is the process of producing fresh water by removing salt from seawater, increasing the total amount of fresh water and ensuring a stable water supply for ships and coastal residents, including drinking water and replenishment. Common seawater desalination methods include reverse osmosis and multi-effect distillation. Reverse osmosis desalination relies on osmotic pressure differences; to ensure the lifespan of the reverse osmosis membrane, the feed water undergoes fine treatment, increasing operating costs and resulting in lower water quality. Multi-effect distillation desalination involves multiple heat exchanges between heated seawater and steam, ultimately condensing the steam into fresh water. However, multi-effect distillation requires high-grade thermal energy, which increases energy consumption when used on ships. Summary of the Invention

[0004] The purpose of this invention is to reduce the energy consumption required for water supply and cooling / heating in ships, and to reduce the environmental pollution caused by refrigerant Freon. It also addresses the problem of underutilization of waste heat from generators in the marine industry. A multi-stage seawater desalination and lithium bromide unit cooling / heating system is proposed. Waste heat from the generator is recovered for freshwater production and cooling / heating, maximizing the recovery of waste heat generated on board. Simultaneously, seawater is heated for cooling / heating in the lithium bromide unit, solving the problem of excessively low seawater temperature and reducing the need for cooling equipment in the unit.

[0005] The multi-stage seawater desalination and lithium bromide unit refrigeration / heating system described in this utility model consists of a steam heater, generator, condenser, absorber, refrigerant pump, solution pump, heat exchanger, and filter. Attached Figure Description

[0006] Figure 1The diagram shows the structure of this utility model. The numbers in the diagram are as follows: 1—Waste heat pipe inlet, 2—Steam heater, 3a, 3b, 3c, 3d, 3e, 3f—Valve, 4—Generator, 5—Baffle plate, 6—First condenser, 7—Seawater pipe outlet, 8—Refrigerated water pipe outlet, 9—Refrigerated water pipe inlet, 10—First evaporator, 11—Refrigerant pump, 12—Solution pump, 13—Absorber, 14—Heat exchanger, 15—Second condenser, 16—Second baffle plate, 17—Second evaporator, 18—Second spray device, 19—Third spray device, 20—Third evaporator, 21—Third condenser, 22—Waste heat pipe outlet, 23—Fresh water pipe outlet, 24—Concentrated brine pipe outlet, 25—Shielded pump, 26—First diaphragm valve, 27—Filter, 28—Second diaphragm valve, 29—Seawater pipe inlet, 30—First spray device. Detailed Implementation

[0007] like Figure 1 The multi-stage seawater desalination and lithium bromide unit refrigeration / heating system shown includes a lithium bromide solution refrigeration / heating circulation pipeline consisting of a generator 4, a baffle plate 5, a first condenser 6, a first evaporator 10, an absorber 13, a refrigerant pump 11, a solution pump 12, a heat exchanger 14, and a first spray device 30; a refrigerant water circulation pipeline consisting of the first condenser 6, the first evaporator 10, the refrigerant pump 11, valve 3d, a chilled water pipeline outlet 8, and a chilled water pipeline inlet 9; a steam heater 2, valves 3a / 3b / 3c, a generator 4, a second evaporator 17, a third evaporator 20, a waste heat pipeline inlet 1, and a waste heat pipeline. The waste heat pipeline consists of outlet 22; the seawater heating circulation pipeline consists of filter 27, first diaphragm valve 26, second diaphragm valve 28, shielded pump 25, second condenser 15, third condenser 21, absorber 13, first condenser 6, valve 3f, seawater pipeline inlet 29, and seawater pipeline outlet 7; the seawater desalination circulation pipeline consists of filter 27, first diaphragm valve 26, second diaphragm valve 28, shielded pump 25, second evaporator 17, second condenser 15, third evaporator 20, third condenser 21, valve 3e, freshwater pipeline inlet 23, concentrated brine pipeline outlet 24, and seawater pipeline inlet 29.

[0008] The lithium bromide solution cooling / heating circulation pipeline, i.e., the dilute lithium bromide solution, exits from the absorber 13, enters the heat exchanger 14 through the refrigerant pump 11, and after gaining part of the heat from the concentrated solution, it passes through the pipeline to the generator 4. After being heated by the residual heat, it evaporates to produce refrigerant vapor. The refrigerant vapor passes through the baffle plate 5 and enters the first condenser 6, where it is condensed into refrigerant water. The refrigerant water is throttled and depressurized before entering the first evaporator 10. The remaining refrigerant water continues to enter the first evaporator 10 through the refrigerant pump 11 and valve 3d, where it is fully heated and evaporated by the refrigerant water from the refrigerant water pipeline inlet 9. The evaporated refrigerant vapor then passes through the baffle plate 5 and enters the absorber 13. The concentrated solution from the generator 4 enters the heat exchanger 14 and exchanges heat with the dilute solution. After passing through the first spray device 30, it absorbs the refrigerant vapor from the first evaporator 10 and becomes a dilute solution. At the same time, the refrigerant water that has absorbed heat is supplied to the user through the refrigerant water pipeline outlet 8.

[0009] The waste heat pipeline, which uses waste heat from the engine or other sources on the ship, enters the system through inlet 1. When the heat is insufficient, the waste heat is heated by steam heater 2 and then enters generator 4. Valve 3a is closed, while valves 3b and 3c are open. When the waste heat is sufficient, valve 3a is open, while valves 3b and 3c are closed. The waste heat enters generator 4 and heats the dilute solution before entering the second evaporator 17. In the second evaporator 17, seawater is heated, causing the seawater to undergo its first desalination evaporation. After exiting the second evaporator 17, the waste heat directly enters the third evaporator 20, where it heats the fresh water condensed after the first evaporation, causing the seawater to undergo its second desalination evaporation. Finally, the waste heat is discharged through waste heat pipeline outlet 22.

[0010] It should be noted that when the ship's waste hot water is insufficient, the waste hot water can be discharged through the waste heat pipeline outlet 22 and then continue to circulate and be heated in the waste heat pipeline inlet 1.

[0011] The seawater heating circulation pipeline draws water from the ocean. Seawater enters through inlet 29 and passes through filter 27 to remove impurities and sediment. The output of filter 27 is connected to the input of shielded pump 25. The filtered seawater is divided into two streams. One stream enters the second evaporator 17 through valve 3e, becoming the raw material for multi-stage seawater desalination. The other stream enters the heat transfer tubes of the third condenser 21 and the second condenser 15 through valve 3f, condensing freshwater vapor and increasing its temperature. It then enters the absorber 13 and the first condenser 6, absorbing heat from the absorber 13 and the first condenser 6 respectively, and is finally discharged through outlet 7 of the seawater pipeline.

[0012] It should be noted that the seawater through the seawater pipeline outlet 7 can be discharged or enter the first evaporator 10 through valve 3e for multi-stage seawater desalination.

[0013] It should be noted that the first diaphragm valve 26 and the second diaphragm valve 28 are located at both ends of the filter 27 to facilitate filter replacement and maintenance.

[0014] The multi-stage desalination circulation pipeline: A portion of the filtered seawater enters the second evaporator 17 through valve 3e, is sprayed by the second spray device 18, and is heated and evaporated by the residual hot water from generator 4. The evaporated freshwater vapor passes through the second baffle plate 16 and enters the second condenser 15, where it exchanges heat with another portion of the seawater and condenses. The condensed freshwater is then throttled and depressurized before entering the third evaporator 20. After being sprayed by the third spray device 19, it is heated and evaporated by the residual hot water from the second evaporator 17. The evaporated freshwater vapor passes through the second baffle plate 16 and enters the third condenser 21. The condensed freshwater is discharged through the freshwater pipeline outlet 23. Concentrated brine is discharged through the concentrated brine pipeline 24.

[0015] It should be noted that the fresh water from the fresh water outlet 23 can be connected to the chilled water inlet 9 to use the desalinated seawater as the chilled water required for cooling.

[0016] It should be noted that during heating operation, the waste heat is heated by the steam heater 2 and used as the driving heat source, while the seawater in the seawater heating circulation pipeline is used as the heat transfer medium to provide heat.

[0017] This invention makes full use of the waste heat in ships to improve energy efficiency, while matching refrigeration with seawater desalination. This not only increases the total amount of fresh water, but also meets the demand for refrigeration / heating, reduces environmental pollution, and lowers energy consumption by using low-grade heat energy.

[0018] The above description is merely an application example of this utility model and does not limit the patent scope of this utility model. Any equivalent structure made using the content of this specification and drawings, whether directly or indirectly applied in related technical fields, is similarly included within the patent protection scope of this utility model.

Claims

1. A multi-stage seawater desalination and lithium bromide unit refrigeration / heating system, characterized in that, It includes a lithium bromide solution cooling / heating circulation pipeline, a refrigerant water circulation pipeline, a waste heat pipeline, a seawater heating circulation pipeline, and a seawater desalination circulation pipeline; the lithium bromide solution cooling / heating circulation pipeline consists of a generator (4), a baffle plate (5), a first condenser (6), a first evaporator (10), an absorber (13), a refrigerant pump (11), a solution pump (12), a heat exchanger (14), and a first spray device (30); the refrigerant water circulation pipeline consists of a first condenser (6), a first evaporator (10), a refrigerant pump (11), a valve (3d), a refrigerant water pipeline outlet (8), and a refrigerant water pipeline inlet (9); the waste heat pipeline consists of a steam heater (2), a valve (3a), and a valve (3b). The system consists of a valve (3c), a generator (4), a second evaporator (17), a third evaporator (20), a waste heat pipeline inlet (1), and a waste heat pipeline outlet (22); the seawater heating circulation pipeline consists of a filter (27), a first diaphragm valve (26), a second diaphragm valve (28), a shielded pump (25), a second condenser (15), a third condenser (21), an absorber (13), a first condenser (6), a valve (3f), a seawater pipeline inlet (29), and a seawater pipeline outlet (7); the seawater desalination circulation pipeline consists of a filter (27), a first diaphragm valve (26), a second diaphragm valve (28), a shielded pump (25), a second evaporator (17), a second condenser (15), a third evaporator (20), a third condenser (21), a valve (3e), a second spray device (18), a third spray device (19), a freshwater pipeline inlet (23), a concentrated brine pipeline outlet (24), and a seawater pipeline inlet (29).

2. The lithium bromide solution cooling / heating circulation pipeline and refrigerant water circulation pipeline of the multi-stage seawater desalination and lithium bromide unit cooling / heating system according to claim 1, characterized in that: Dilute lithium bromide solution exits from absorber (13), enters heat exchanger (14) via solution pump (12), and after obtaining part of the heat from concentrated solution, it passes through pipe to generator (4). After being heated by residual heat, it generates refrigerant vapor. The refrigerant vapor passes through baffle plate (5) and enters first condenser (6) to condense into refrigerant water. The refrigerant water is throttled and depressurized before entering first evaporator (10). The remaining refrigerant water enters first evaporator (10) again via refrigerant pump (11) and valve (3d), where it is fully heated and evaporated by refrigerant water from refrigerant water pipeline inlet (9). The evaporated refrigerant vapor then enters absorber (13) via baffle plate (5). The concentrated solution exiting generator (4) enters heat exchanger (14) and exchanges heat with dilute solution. After passing through first spray device (30), it absorbs refrigerant vapor from first evaporator (10) and becomes dilute solution. At the same time, the refrigerant water that has absorbed heat is supplied to users through refrigerant water pipeline outlet (8).

3. The waste heat pipeline of the multi-stage seawater desalination and lithium bromide unit refrigeration / heating system according to claim 1, characterized in that: Waste heat from the engine or other waste heat from the ship enters the system through the waste heat pipeline inlet (1). When the heat is insufficient, the waste heat is heated by the steam heater (2) and then enters the generator (4). Valve (3a) is closed, and valves (3b) and (3c) are opened. When the waste heat is sufficient, valve (3a) is opened, and valves (3b) and (3c) are closed. The waste heat enters the generator (4) to heat the dilute solution and then enters the second evaporator (17). The seawater is heated in the second evaporator (17) to cause the seawater to undergo desalination and evaporation for the first time. The waste heat is connected from the second evaporator (17) to the third evaporator (20) to heat the fresh water after the first condensation, causing the seawater to undergo desalination and evaporation for the second time. Finally, the waste heat is discharged through the waste heat pipeline outlet (22).

4. The seawater heating circulation pipeline and seawater desalination circulation pipeline of the multi-stage seawater desalination and lithium bromide unit refrigeration / heating system according to claim 1, characterized in that: Seawater enters through the seawater pipeline inlet (29), passes through the second diaphragm valve (28), filter (27), and first diaphragm valve (26). The output end of the first diaphragm valve (26) is connected to the input end of the shielded pump (25). The filtered seawater is divided into two parts. The part of the seawater desalination circulation pipeline enters the second evaporator (17) through valve (3e) to become the raw material for multi-stage seawater desalination. It enters the second evaporator (17) and is sprayed by the second spray device (18). It is heated and evaporated by the residual hot water from the generator (4). The evaporated freshwater vapor enters the second condenser (15) through the second baffle plate (16) and exchanges heat with the other part of the seawater for condensation. The condensed freshwater is throttled and depressurized before entering the third evaporator. (20) The water is sprayed by the third spray device (19) and heated and evaporated by the residual hot water from the second evaporator (17). The evaporated fresh water vapor enters the third condenser (21) through the second baffle plate (16). After condensation, the fresh water is discharged through the fresh water pipeline outlet (23), and the concentrated brine is discharged through the concentrated brine pipeline (24). Another part of the seawater in the seawater heating circulation pipeline enters the heat transfer tube of the third condenser (21) and the heat transfer tube of the second condenser (15) through the valve (3f) to condense the fresh water vapor. Then it enters the absorber (13) and the first condenser (6) in sequence to absorb the heat of the absorber (13) and the heat of the first condenser (6) respectively. Finally, it is discharged through the seawater pipeline outlet (7).

5. The multi-stage seawater desalination and lithium bromide unit refrigeration / heating system according to claim 1, characterized in that: in When the amount of waste hot water in the ship is insufficient, the waste hot water can be discharged through the outlet (22) of the waste heat pipeline and then continue to enter the inlet (1) of the waste heat pipeline for circulation heating.

6. The multi-stage seawater desalination and lithium bromide unit refrigeration / heating system according to claim 1, characterized in that: The freshwater pipeline outlet (23) can be connected to the chilled water pipeline inlet (9) to use the desalinated seawater as the chilled water required for refrigeration.

7. The multi-stage seawater desalination and lithium bromide unit refrigeration / heating system according to claim 1, characterized in that: Seawater from the seawater pipeline outlet (7) can be discharged or enter the first evaporator (10) through the valve (3e) for multi-stage seawater desalination.

8. The multi-stage seawater desalination and lithium bromide unit refrigeration / heating system according to claim 1, characterized in that: The first diaphragm valve (26) and the second diaphragm valve (28) are located at both ends of the filter (27) to facilitate filter replacement and maintenance.

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