CN216897896U - Device for heating circulating mother liquor by using waste heat of alumina evaporation process - Google Patents

Abstract

The utility model discloses a device for heating and circulating mother liquor by utilizing waste heat of an alumina evaporation process, which comprises a mother liquor tank, wherein an inlet of the mother liquor tank is communicated with a mother liquor main pipe for conveying an effect liquid of an evaporation device V; a first electromagnetic valve is arranged on the mother liquor main pipe, and a temperature sensor is arranged at the outlet end of the mother liquor main pipe; the output end of the temperature sensor is connected with a PLC (programmable logic controller), the output end of the PLC is connected with the controlled end of the first electromagnetic valve, and the mother liquor main pipe is connected with a lithium bromide absorption heat pump unit for heating the evaporation device V effect liquid through a communicated first pipeline; the waste heat inlet of the lithium bromide absorption heat pump unit is connected with the VI-effect waste steam of the evaporation device through a connected waste steam access pipeline, and the hot water outlet of the lithium bromide absorption heat pump unit is communicated with the mother liquor main pipe through a communicated second pipeline. The utility model not only can save the steam consumption of the next procedure, but also can reduce the consumption of water and electricity in the VI-effect exhaust steam condensation process.

Description

A device for heating the circulating mother liquor by the waste heat of the alumina evaporation process

technical field

The utility model relates to the technical field of waste heat recovery, in particular to a device for heating a circulating mother liquor by utilizing the waste heat of an alumina evaporation process.

Background technique

Alumina production enterprises belong to high energy consumption industries. With the concept of low-carbon production, energy saving and consumption reduction has become an urgent problem for alumina production enterprises.

In alumina production enterprises, the consumption of steam is very large, especially in the evaporation process, which accounts for about 30% of the total steam consumption of the enterprise. A six-effect countercurrent tubular evaporation device is used for the evaporation of sodium hydroxide circulating mother liquor in alumina production enterprises. During the production process, a large amount of secondary steam is generated. Directly enter the condenser, cool it with water and condense it into water and remove it. This process not only wastes the heat energy of the exhausted steam in the VI effect (final effect) of the evaporation device, but also increases the consumption of water and electricity. Therefore, it is an urgent problem to be solved by the technicians at this stage to be able to recover and utilize the heat energy of the exhausted steam of the VI effect (final effect) of the evaporation device.

Utility model content

The technical problem to be solved by this utility model is to provide a device for heating the circulating mother liquor by utilizing the waste heat of the alumina evaporation process, which can not only recycle the thermal energy of the evaporation device's VI-efficiency exhausted steam, but also reduce the amount of time in the evaporation device's VI-efficiency exhausted steam condensation process. Water and electricity consumption.

In order to solve the above-mentioned technical problems, the technical solutions adopted by the present invention are as follows.

A device for heating circulating mother liquor by utilizing the waste heat of the alumina evaporation process, including a mother liquor tank, the inlet of the mother liquor tank is connected with a mother liquor main pipe for conveying the V-effect liquid of the evaporation device; Solenoid valve, the outlet end of the mother liquor main pipe is provided with a temperature sensor; the output end of the temperature sensor is connected with a PLC controller, and the output end of the PLC controller is connected with the controlled end of the first solenoid valve, wherein, on the mother liquor main pipe A lithium bromide absorption heat pump unit for heating the V-effect effluent of the evaporation device is connected through the connected first pipeline located in front of the first solenoid valve; the waste heat inlet of the lithium bromide absorption heat pump unit is connected to the pipeline through the connected exhaust steam Evaporation device VI is connected with exhausted steam, and the hot water outlet of the lithium bromide absorption heat pump unit is communicated with the mother liquor main pipe through a connected second pipeline located behind the first electromagnetic valve.

Preferably, the lithium bromide absorption heat pump unit includes an evaporator, an absorber, a regenerator and a condenser; the waste heat inlet of the lithium bromide absorption heat pump unit is arranged on the evaporator, and the low pressure flash steam outlet of the evaporator is connected to the absorber. The low-pressure flash steam inlet of the absorber is connected; the inside of the absorber is provided with lithium bromide concentrated solution, the lithium bromide absorption heat pump unit is connected with the first pipeline through the cold water inlet set on the absorber, and the lithium bromide solution inlet of the absorber is connected with the lithium bromide solution of the regenerator. The solution outlet is connected, the lithium bromide solution outlet of the absorber is connected with the lithium bromide solution inlet of the regenerator through the connected third pipeline, and the hot water outlet of the absorber is connected with the hot water inlet of the condenser; the driving steam inlet of the regenerator is connected by connecting The driving steam access pipeline is connected with a high temperature heat source, and the lithium bromide solution evaporation secondary steam outlet of the regenerator is connected with the evaporation secondary steam inlet of the condenser; the hot water outlet of the lithium bromide absorption heat pump unit is arranged on the condenser, and the condensation The secondary steam condensed water outlet of the evaporator is connected with the secondary steam condensed water inlet of the evaporator.

Preferably, the exhaust steam condensate outlet of the evaporator and the driving steam condensate water outlet of the regenerator are respectively connected to a condensate tank through the connected exhaust steam condensate liquid outlet pipe and driving steam condensate liquid outlet pipe.

Preferably, a lithium bromide solution circulating pump for transporting the dilute lithium bromide solution in the absorber to the regenerator is provided on the third pipeline connected between the absorber and the regenerator, and the controlled end of the lithium bromide solution circulating pump is connected to PLC control output of the device.

Preferably, the controlled end of the high temperature heat source is connected to the output end of the PLC controller.

Preferably, the first pipeline is provided with a third solenoid valve for controlling the on-off of the first pipeline and a mother liquor pressurizing pump for pumping the V-effect effluent of the evaporation device into the lithium bromide absorption heat pump unit. The third solenoid valve Both the controlled end of the mother liquor pressurizing pump are connected to the output end of the PLC controller.

Preferably, the second pipeline is provided with a second solenoid valve for controlling the on-off of the second pipeline, and the controlled end of the second solenoid valve is connected to the output end of the PLC controller.

Due to the adoption of the above technical solutions, the technical progress achieved by the present utility model is as follows.

The utility model adopts a lithium bromide absorption heat pump unit to recover the waste heat of the V-effect exhausted steam in the evaporation process of the alumina enterprise, and heat up the V-effect effluent of the evaporation device, so that the temperature of the material transported to the mother liquor tank by the V-effect effluent of the evaporation device reaches about 95 DEG C. It not only saves the consumption of new steam in the next process, but also reduces the consumption of water and electricity in the condensation process of the VI effect of the evaporation device.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a flow chart of the heating process of the V-effect effluent of the evaporation device by the lithium bromide absorption heat pump unit of the present invention.

Among them: 1. Lithium bromide absorption heat pump unit, 11. Evaporator, 12. Spent steam access pipeline, 13. Spent steam condensate outlet pipeline, 14. Absorber, 15. Regenerator, 16. Drive steam access pipeline , 17. Drive steam condensate water outlet pipeline, 18. Condenser, 19. Lithium bromide solution circulation pump, 2. Mother liquor pressurization pump, 3. First pipeline, 4. Second pipeline, 5. Mother liquor main pipe, 6. Evaporation Device VI is exhausted steam, 7. Condensate tank, 8. Drive steam source, 9. Mother liquor tank.

Detailed ways

The present utility model will be described in further detail below with reference to the accompanying drawings and specific embodiments.

A device for utilizing the waste heat of the alumina evaporation process to heat the circulating mother liquor, as shown in FIG. 1 , comprising a mother liquor tank 9 and a PLC controller, wherein the inlet of the mother liquor tank 9 is communicated with a mother liquor manifold 5, and the mother liquor manifold 5 is communicated with a first mother liquor. Pipe 3, the outlet end of the mother liquor main pipe 5 is provided with a temperature sensor; the input end of the PLC controller is connected to the output end of the temperature sensor, and the PLC controller is used to control the temperature of the mother liquor flowing into the mother liquor tank 9.

The inlet end of the mother liquor main pipe 5 is connected with the V-effect liquid outlet of the evaporation device, so as to transport the V-effect liquid of the evaporation device. The first pipeline 3 is connected with the lithium bromide absorption heat pump unit 1 . Lithium bromide absorption heat pump unit 1 is a device that transfers heat from low temperature to high temperature with thermal energy as compensation. It is an energy-saving equipment for recycling waste heat. It can widely absorb low-temperature waste heat of 10-60 °C and produce water or materials below 100 °C. Meet process heat requirements.

The lithium bromide absorption heat pump unit 1 is an endothermic heat pump unit, as shown in FIG. 2 , including an evaporator 11, an absorber 14, a regenerator 15 and a condenser 18, wherein the evaporator 11 is in a vacuum state, and the evaporator 11 The waste heat inlet of the lithium bromide absorption heat pump unit 1 is used as the waste heat inlet of the lithium bromide absorption heat pump unit 1, and is connected with the evaporation device VI effect waste steam 6 through the connected spent steam access pipeline 12; the low pressure flash steam outlet of the evaporator 11 and the low pressure flash of the absorber 14 The steam inlet is connected; the exhausted steam condensed water outlet of the evaporator 11 is connected with the condensed water tank 7 through the connected exhausted steam condensed water outlet pipe 13 .

The inside of the absorber 14 is provided with lithium bromide concentrated solution; the cold water inlet set on the absorber 14 is connected with the first pipeline 3 as the cold water inlet of the lithium bromide absorption heat pump unit 1, and the first pipeline 3 is provided with a mother liquor pressurizing pump 2, and the mother liquor The booster pump 2 is used to pump the V-effect effluent of the evaporation device in the mother liquor main pipe 5 into the lithium bromide absorption heat pump unit 1, and the controlled end of the mother liquor booster pump 2 is connected to the output end of the PLC controller; the lithium bromide solution inlet of the absorber 14 Be connected with the lithium bromide solution outlet of the regenerator 15; the lithium bromide solution outlet of the absorber 14 is connected with the lithium bromide solution inlet of the regenerator 15 through the connected third pipeline, and the third pipeline is provided with a lithium bromide solution circulating pump 19, a lithium bromide solution circulating pump 19 For transporting the dilute lithium bromide solution in the absorber 14 to the regenerator 15, the controlled end of the lithium bromide solution circulating pump 19 is connected to the output end of the PLC controller; the hot water outlet of the absorber 14 is connected to the hot water inlet of the condenser 18 .

The driving steam inlet of the regenerator 15 is connected with a high temperature heat source through the connected driving steam access pipe 16. In this embodiment, the driving steam source 8 is selected as the high temperature heat source, and the controlled end of the high temperature heat source is connected with the output end of the PLC controller; regeneration The lithium bromide solution evaporation secondary steam outlet of the regenerator 15 is connected with the lithium bromide solution evaporation secondary steam inlet of the condenser 18; the driving steam condensate water outlet of the regenerator 15 is also connected to the condensate tank 7 through the connected driving steam condensate water outlet pipe 17 .

The hot water outlet of the condenser 18 is used as the hot water outlet of the lithium bromide absorption heat pump unit 1, and is communicated with the mother liquor main pipe 5 through the connected second pipeline 4; Steam condensate inlet connection.

When in use, the water in the evaporator 11 is evaporated under low pressure and absorbs the heat from the exhausted steam 6 of the evaporation device VI and flashes to steam at a lower temperature, and the exhausted steam 6 of the evaporation device is formed into condensed water and sent to the condensed water tank 7 for For other work or users; the generated low-pressure flash steam enters the absorber 14 and is mixed with the lithium bromide concentrated solution, the lithium bromide concentrated solution becomes the lithium bromide dilute solution, and releases heat, which is effective for the evaporation device V entering the heat exchanger of the absorber 14. The effluent is heated once, and the V-effect effluent of the heated evaporation device enters the condenser 18 heat exchanger; the lithium bromide solution circulating pump 19 transports the lithium bromide dilute solution in the absorber 14 to the regenerator 15, and enters the regenerator 15. The lithium bromide dilute solution is heated by the driving steam source 8 entering the heat exchanger of the regenerator 15, and the lithium bromide dilute solution in the regenerator 15 is evaporated and concentrated to become a lithium bromide concentrated solution and is returned to the absorber 14, and the lithium bromide solution in the regenerator 15 evaporates secondary steam Enter the condenser 18, drive the steam source 8 to become condensed water and send it to the condensed water tank 7; the lithium bromide solution in the condenser 18 evaporates the secondary steam to the evaporation device V from the absorber 14 heat exchanger entering the condenser 18 heat exchanger. After the liquid is heated for the second time, the V-effect effluent of the evaporation device is sent to the mother liquor main pipe 5 through the second pipeline 4, and finally sent to the mother liquor tank 9;

The mother liquor main pipe 5 is provided with a first solenoid valve, the first solenoid valve is used to control the on-off of the mother liquid main pipe 5, and the controlled end of the first solenoid valve is connected to the output end of the PLC controller.

The first pipeline 3 is located in front of the first solenoid valve. The first pipeline 3 is provided with a third solenoid valve. The third solenoid valve is used to control the on-off of the first pipeline 3. The controlled end of the third solenoid valve is connected to the PLC control. output of the device.

The second pipeline 4 is located behind the first solenoid valve. The second pipeline 4 is provided with a second solenoid valve. The second solenoid valve is used to control the on-off of the second pipeline 4. The controlled end of the second solenoid valve is connected to the PLC control. output of the device.

The PLC controller monitors the temperature of the evaporating device V that flows into the mother liquor tank 9 according to the temperature sensor, and controls the use of steam to drive the absorption and evaporation device VI by adjusting the mother liquor pressurizing pump 2, driving the steam source 8, and the lithium bromide solution circulating pump 19. The heat of the steam 6 is heated to heat the V-effect liquid of the evaporation device, so that the V-effect liquid temperature of the evaporation device flowing into the mother liquor tank 9 reaches about 95 °C.

When the utility model is in use, the first solenoid valve is closed, the second solenoid valve and the third solenoid valve are opened, the mother liquor pressurizing pump 2 is opened, and the V-effect effluent of the evaporation device is pumped into the lithium bromide absorption heat pump unit 1; the lithium bromide absorption heat pump The unit 1 uses the driving steam source 8 to drive and absorb the heat of the V-effect exhausted steam 6 of the connected evaporation device, and heat the V-effect liquid of the evaporation device, so that the V-effect liquid temperature of the evaporation device reaches about 95 °C, which not only can improve the V-efficiency exhausted steam of the evaporation device. 6. The heat energy can be recycled to save the consumption of new steam in the next process, and it can also reduce the consumption of water and electricity in the condensation process of the VI-efficiency exhausted steam of the evaporation device.

Claims (7)

1. The device for heating and circulating the mother liquor by utilizing the waste heat of the alumina evaporation process comprises a mother liquor tank (9), wherein an inlet of the mother liquor tank (9) is communicated with a mother liquor main pipe (5) for conveying the effect liquid of an evaporation device V; a first electromagnetic valve for controlling the on-off of the mother liquor main pipe (5) is arranged on the mother liquor main pipe (5), and a temperature sensor is arranged at the outlet end of the mother liquor main pipe (5); the output of temperature sensor is connected with the PLC controller, and the output of PLC controller is connected with the controlled end of first solenoid valve, its characterized in that: the mother liquor main pipe (5) is connected with a lithium bromide absorption heat pump unit (1) used for heating the effect liquid of the evaporation device V through a first pipeline (3) which is communicated and positioned in front of the first electromagnetic valve; the waste heat inlet of the lithium bromide absorption heat pump unit (1) is connected with an evaporation device VI-effect waste steam (6) through a connected waste steam access pipeline (12), and the hot water outlet of the lithium bromide absorption heat pump unit (1) is communicated with a mother liquor main pipe (5) through a communicated second pipeline (4) which is positioned behind a first electromagnetic valve.

2. The apparatus for heating a circulating mother liquor using waste heat of an alumina evaporation process according to claim 1, wherein: the lithium bromide absorption heat pump unit (1) comprises an evaporator (11), an absorber (14), a regenerator (15) and a condenser (18); a waste heat inlet of the lithium bromide absorption heat pump unit (1) is arranged on the evaporator (11), and a low-pressure flash steam outlet of the evaporator (11) is connected with a low-pressure flash steam inlet of the absorber (14); a lithium bromide concentrated solution is arranged in the absorber (14), the lithium bromide absorption heat pump unit (1) is connected with the first pipeline (3) through a cold water inlet arranged on the absorber (14), a lithium bromide solution inlet of the absorber (14) is connected with a lithium bromide solution outlet of the regenerator (15), a lithium bromide solution outlet of the absorber (14) is connected with a lithium bromide solution inlet of the regenerator (15) through a connected third pipeline, and a hot water outlet of the absorber (14) is connected with a hot water inlet of the condenser (18); a driving steam inlet of the regenerator (15) is connected with a high-temperature heat source through a connected driving steam access pipeline (16), and a lithium bromide solution evaporation secondary steam outlet of the regenerator (15) is connected with a lithium bromide solution evaporation secondary steam inlet of the condenser (18); a hot water outlet of the lithium bromide absorption heat pump unit (1) is arranged on a condenser (18), and a secondary steam condensate outlet of the condenser (18) is connected with a secondary steam condensate inlet of an absorber (14).

3. The apparatus for heating a circulating mother liquor using waste heat of an alumina evaporation process according to claim 2, wherein: and an exhaust steam condensate outlet of the evaporator (11) and a driving steam condensate outlet of the regenerator (15) are respectively connected with a condensate tank (7) through an exhaust steam condensate outlet pipeline (13) and a driving steam condensate outlet pipeline (17) which are connected with each other.

4. The apparatus for heating a circulating mother liquor using waste heat of an alumina evaporation process according to claim 2, wherein: a lithium bromide solution circulating pump (19) used for conveying the dilute solution in the absorber (14) to the regenerator (15) is arranged on a third pipeline connected between the absorber (14) and the regenerator (15), and the controlled end of the lithium bromide solution circulating pump (19) is connected with the output end of the PLC.

5. The apparatus for heating a circulating mother liquor using waste heat of an alumina evaporation process according to claim 2, wherein: and the controlled end of the high-temperature heat source is connected with the output end of the PLC.

6. The apparatus for heating a circulating mother liquor using waste heat of an alumina evaporation process according to claim 1, wherein: the first pipeline (3) is provided with a third electromagnetic valve for controlling the on-off of the first pipeline (3) and a mother liquor pressure pump (2) for pumping the evaporation plant V-effect liquid into the lithium bromide absorption heat pump unit (1), and the controlled ends of the third electromagnetic valve and the mother liquor pressure pump (2) are connected with the output end of the PLC controller.

7. The apparatus for heating a circulating mother liquor using waste heat of an alumina evaporation process according to claim 1, wherein: and a second electromagnetic valve used for controlling the on-off of the second pipeline (4) is arranged on the second pipeline (4), and the controlled end of the second electromagnetic valve is connected with the output end of the PLC.

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