A system for recovering cold energy of scattered low-temperature liquid by using a heat exchange device

Abstract

The utility model discloses a system of recovery scattered low temperature liquid cold energy with heat exchange device, including heat exchanger device, refrigerant intermediate tank, condenser and fan, heat exchanger device includes first heat exchange fluid passage and second heat exchange fluid passage, and the import of first heat exchange fluid passage is connected to lithium hexafluorophosphate crystal analysis kettle's mother liquor main pipe, and the export of first heat exchange fluid passage is connected to mother liquor tank, the hot end export of refrigerant intermediate tank is connected to the import of second heat exchange fluid passage of heat exchanger device, and the export of second heat exchange fluid passage of heat exchanger device is connected to the cold end import of refrigerant intermediate tank, the cold end export of refrigerant intermediate tank is connected to the refrigerant import of condenser, and the refrigerant export of condenser is connected to the hot end import of refrigerant intermediate tank, the import of fan is connected with outside air, and the export of fan is connected to the air import of condenser, and the air export of condenser is connected to the phosphorus pentachloride feeding room.

Description

Technical Field

[0001] This application relates to the field of chemical process equipment technology, and in particular to a system for recovering scattered cryogenic liquid cold energy using a heat exchange device. Background Technology

[0002] In the existing process, after the crystallization is completed in the lithium hexafluorophosphate crystallization reactor, the low-temperature mother liquor is directly transported into the mother liquor tank, where it is heated by a heat medium. This wastes the cold energy of the low-temperature mother liquor and consumes the heat energy of the heat medium.

[0003] Because the exhaust gas treatment system continuously draws air out of the phosphorus pentachloride feeding room, fresh air needs to be introduced from the outside. If humid air is introduced into the feeding room, the water vapor in the air will react with the escaped material to produce acidic substances, which will severely corrode the equipment and increase the labor intensity of the workers.

[0004] Therefore, those skilled in the art are dedicated to developing a system that utilizes heat exchange devices to recover scattered cryogenic liquid cold energy in order to overcome the problems existing in the prior art. Utility Model Content

[0005] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by this utility model is how to recover the cold energy of scattered low-temperature mother liquor and reduce the consumption of heat energy; at the same time, improve the working environment, reduce equipment corrosion, and reduce equipment failure rate.

[0006] To achieve the above objectives, this utility model provides a system for recovering scattered cryogenic liquid cold energy using a heat exchange device, comprising: A heat exchanger device, comprising a first heat exchange fluid channel and a second heat exchange fluid channel, wherein the inlet of the first heat exchange fluid channel is connected to the main discharge pipe of the mother liquor from the lithium hexafluorophosphate crystallization vessel, and the outlet of the first heat exchange fluid channel is connected to the mother liquor tank. A refrigerant intermediate tank, the hot end outlet of which is connected to the inlet of the second heat exchange fluid channel of the heat exchanger device, and the outlet of the second heat exchange fluid channel of the heat exchanger device is connected to the cold end inlet of the refrigerant intermediate tank. The condenser, wherein the cold end outlet of the refrigerant intermediate tank is connected to the refrigerant inlet of the condenser, and the refrigerant outlet of the condenser is connected to the hot end inlet of the refrigerant intermediate tank; and The fan has its inlet connected to the outside air, its outlet connected to the air inlet of the condenser, and its air outlet connected to the phosphorus pentachloride feeding room.

[0007] Furthermore, the refrigerant intermediate tank is equipped with a level transmitter and a first temperature transmitter.

[0008] Furthermore, the heat exchanger device includes multiple heat exchangers connected in sequence. Each heat exchanger includes a first heat exchange fluid channel and a second heat exchange fluid channel. The inlet of the first heat exchange fluid channel of each heat exchanger is connected to the main discharge pipe of a plurality of lithium hexafluorophosphate crystallization vessels. The outlet of the first heat exchange fluid channel of each heat exchanger is connected to one of a plurality of mother liquor tanks. The hot end outlet of the refrigerant intermediate tank is connected to the inlet of the second heat exchange fluid channel of the last heat exchanger. The outlet of the second heat exchange fluid channel of the next heat exchanger is connected to the inlet of the second heat exchange fluid channel of the previous heat exchanger. The outlet of the second heat exchange fluid channel of the first heat exchanger is connected to the cold end inlet of the refrigerant intermediate tank.

[0009] Furthermore, a second temperature transmitter is installed at the outlet of the first heat exchange fluid channel of each heat exchanger.

[0010] Furthermore, it also includes a first refrigerant circulation pump, and the hot end outlet of the refrigerant intermediate tank is connected to the inlet of the second heat exchange fluid channel of the heat exchanger device via the first refrigerant circulation pump.

[0011] Furthermore, the outlet of the first refrigerant circulation pump is connected to the first return port of the refrigerant intermediate tank via a first return valve and a first return pipe.

[0012] Furthermore, the inlet of the first refrigerant circulation pump is provided with a first shut-off valve, the outlet of the first refrigerant circulation pump is provided with a second shut-off valve, the inlet of the first refrigerant circulation pump is provided with a first drain valve, and the outlet of the first refrigerant circulation pump is provided with a first pressure transmitter.

[0013] Furthermore, it also includes a second refrigerant circulation pump, the cold end outlet of the refrigerant intermediate tank being connected to the refrigerant inlet of the condenser via the second refrigerant circulation pump.

[0014] Furthermore, the outlet of the second refrigerant circulation pump is connected to the second return port of the refrigerant intermediate tank via a second return valve and a second return pipe.

[0015] Furthermore, the inlet of the second refrigerant circulation pump is equipped with a third shut-off valve, the outlet of the second refrigerant circulation pump is equipped with a fourth shut-off valve, the inlet of the second refrigerant circulation pump is equipped with a second drain valve, and the outlet of the second refrigerant circulation pump is equipped with a second pressure transmitter.

[0016] The beneficial effects of this utility model are: 1. The temperature of the low-temperature mother liquor increases after the cold energy is recovered, which reduces the heat energy consumption for heating it.

[0017] 2. The recovered cold energy is comprehensively utilized to improve the working environment, reduce the labor intensity of staff, and at the same time reduce equipment corrosion and lower equipment failure rate.

[0018] The following will further explain the concept, specific structure and technical effects of this utility model in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of this utility model. Attached Figure Description

[0019] Figure 1 This is a system diagram of a preferred embodiment of the present invention.

[0020] Among them, 11-first heat exchanger, 12-second heat exchanger, 13-third heat exchanger, 14-fourth heat exchanger, 20-refrigerant intermediate tank, 30-condenser, 31-drain valve, 40-fan, 51-first refrigerant circulation pump, 52-first shut-off valve, 53-second shut-off valve, 54-first return valve, 55-first return pipe, 56-first drain valve, 51-second refrigerant circulation pump, 62-third shut-off valve, 63-fourth shut-off valve, 64-second return valve, 65-second return pipe, 66-second drain valve. Detailed Implementation

[0021] The preferred embodiments of this utility model are described below with reference to the accompanying drawings to make the technical content clearer and easier to understand. This utility model can be embodied in many different forms, and the scope of protection of this utility model is not limited to the embodiments mentioned herein.

[0022] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and this invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0023] In the existing process, after crystallization in the lithium hexafluorophosphate crystallization reactor, the low-temperature mother liquor is directly transferred to a mother liquor tank, where it is heated using a heat transfer medium. If the low-temperature mother liquor were heated in advance using a heat exchanger to recover its cold energy before entering the mother liquor tank, the heat consumption would be reduced. Because the tail gas treatment system continuously extracts air from the phosphorus pentachloride feeding room, fresh air needs to be supplied from the outside.

[0024] This application utilizes a low-temperature mother liquor to cool the refrigerant via a heat exchanger. The cooled refrigerant is stored in an intermediate refrigerant tank, and then a refrigerant pump delivers the low-temperature refrigerant to a condenser to cool the air supplied by the fan, causing water vapor in the air to condense and be removed. This dried air, when then introduced into the feeding room, greatly improves the working environment, reduces equipment corrosion, and lowers the equipment failure rate.

[0025] like Figure 1As shown, this embodiment provides a system for recovering scattered cryogenic liquid cold energy using a heat exchange device, including a first heat exchanger 11, a second heat exchanger 12, a third heat exchanger 13, a fourth heat exchanger 14, a refrigerant intermediate tank 20, a condenser 30, and a fan 40.

[0026] Each heat exchanger includes a first heat exchange fluid channel and a second heat exchange fluid channel. The first heat exchange fluid channel is used for the flow of low-temperature mother liquor (mainly anhydrous hydrogen fluoride) in the lithium hexafluorophosphate crystallization vessel, and the second heat exchange fluid channel is used for the flow of high-temperature refrigerant (mainly organic salt solution). Heat exchange occurs between the first heat exchange fluid channel and the second heat exchange fluid channel, so that the cold energy in the low-temperature mother liquor can be recovered and the temperature of the refrigerant can be reduced.

[0027] In this embodiment, the first heat exchanger 11, the second heat exchanger 12, the third heat exchanger 13, and the fourth heat exchanger 14 are connected sequentially. The inlet of the first heat exchange fluid channel of the first heat exchanger 11 is connected to the main mother liquor discharge pipe A1 of the crystallization reactors #1-#24, and the outlet of the first heat exchange fluid channel of the first heat exchanger 11 is connected to the north line mother liquor tank B1. The inlet of the first heat exchange fluid channel of the second heat exchanger 12 is connected to the main mother liquor discharge pipe A2 of the crystallization reactors #25-#48, and the outlet of the first heat exchange fluid channel of the second heat exchanger 12 is connected to the north line mother liquor tank B1. The inlet of the first heat exchange fluid channel of the third heat exchanger 13 is connected to the main mother liquor discharge pipe A3 of the crystallization reactors #49-#72, and the outlet of the first heat exchange fluid channel of the third heat exchanger 13 is connected to the south line mother liquor tank B2. The inlet of the first heat exchange fluid channel of the fourth heat exchanger 14 is connected to the main mother liquor discharge pipe A4 of the 73#-96# crystallization kettle, and the outlet of the first heat exchange fluid channel of the fourth heat exchanger 14 is connected to the north line mother liquor tank B2.

[0028] The refrigerant intermediate tank 20 is used to store refrigerant. The hot-end outlet of the refrigerant intermediate tank 20 is connected to the inlet of the second heat exchange fluid channel of the fourth heat exchanger 14 via a first shut-off valve 52, a first refrigerant circulation pump 51, and a second shut-off valve 53. The outlet of the second heat exchange fluid channel of the fourth heat exchanger 14 is connected to the inlet of the second heat exchange fluid channel of the third heat exchanger 13. The outlet of the second heat exchange fluid channel of the third heat exchanger 13 is connected to the inlet of the second heat exchange fluid channel of the second heat exchanger 12. The outlet of the second heat exchange fluid channel of the second heat exchanger 12 is connected to the inlet of the second heat exchange fluid channel of the second heat exchanger 11. The outlet of the second heat exchange fluid channel of the first heat exchanger 11 is connected to the cold-end inlet of the refrigerant intermediate tank 20. The first refrigerant circulation pump 51 forces the refrigerant to circulate between the refrigerant intermediate tank 20 and the heat exchangers. After being pressurized by the first refrigerant circulation pump 51, the refrigerant enters the heat exchangers from the hot end of the refrigerant intermediate tank 20, is cooled in the heat exchangers, and then returns to the cold end of the refrigerant intermediate tank 20.

[0029] The refrigerant intermediate tank 20 is equipped with a level transmitter L and a first temperature transmitter T1, which are used to indicate the level and temperature of the refrigerant stored in the refrigerant intermediate tank 20.

[0030] The outlets of the first heat exchange fluid channels of the first heat exchanger 11, the second heat exchanger 12, the third heat exchanger 13, and the fourth heat exchanger 14 are respectively equipped with second temperature transmitters T2, which are used to indicate the temperature of the low-temperature mother liquor after heat exchange.

[0031] The outlet of the second shut-off valve 53 is connected to the first return port of the refrigerant intermediate tank 20 via the first return valve 54 and the first return pipe 55. The inlet of the first refrigerant circulation pump 51 is equipped with a first drain valve 56, and the outlet of the first refrigerant circulation pump 51 is equipped with a first pressure transmitter P1 to indicate the outlet pressure of the first refrigerant circulation pump 51. By setting the first return valve 54 and the first return pipe 55, the outlet pressure of the first refrigerant circulation pump 51 can be prevented from being too high, thereby regulating the refrigerant flow rate through the heat exchanger and stabilizing the liquid level in the refrigerant intermediate tank 20.

[0032] The cold end outlet of the refrigerant intermediate tank 20 is connected to the refrigerant inlet of the condenser 30 via the third shut-off valve 62, the third refrigerant circulation pump 61, and the fourth shut-off valve 63. The refrigerant outlet of the condenser 30 is connected to the hot end inlet of the refrigerant intermediate tank 20. The second refrigerant circulation pump 61 forces the refrigerant to circulate between the refrigerant intermediate tank 20 and the condenser 30. After being pressurized by the second refrigerant circulation pump 61, the refrigerant enters the condenser 30 from the cold end of the refrigerant intermediate tank 20. In the condenser 30, it exchanges heat with the airflow, cooling the airflow blown by the fan 40. Then, the refrigerant returns to the hot end of the refrigerant intermediate tank 20.

[0033] The outlet of the fourth shut-off valve 63 is connected to the second return port of the refrigerant intermediate tank 20 via the second return valve 64 and the second return pipe 65. The inlet of the second refrigerant circulation pump 61 is equipped with a second drain valve 66, and the outlet of the second refrigerant circulation pump 61 is equipped with a second pressure transmitter P2 to indicate the outlet pressure of the second refrigerant circulation pump 61. By setting the second return valve 64 and the second return pipe 65, the outlet pressure of the second refrigerant circulation pump 61 can be prevented from being too high, thereby regulating the refrigerant flow through the condenser 30 and stabilizing the liquid level in the refrigerant intermediate tank 20.

[0034] The inlet of the blower 40 is connected to the outside air, and the outlet of the blower 40 is connected to the air inlet of the condenser 30. The air outlet of the condenser 30 is connected to the phosphorus pentachloride feeding room C, which can supply dry air to the phosphorus pentachloride feeding room C. The bottom of the condenser 30 is connected to the exhaust gas system D via a drain valve 31, which can discharge condensate into the exhaust gas system D.

[0035] The beneficial effects of this utility model are: 1. The temperature of the low-temperature mother liquor increases after the cold energy is recovered, which reduces the heat energy consumption for heating it.

[0036] 2. The recovered cold energy is comprehensively utilized to improve the working environment, reduce the labor intensity of staff, and at the same time reduce equipment corrosion and lower equipment failure rate.

[0037] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A system for recovering scattered cryogenic liquid cold energy using a heat exchange device, characterized in that, include: A heat exchanger device, comprising a first heat exchange fluid channel and a second heat exchange fluid channel, wherein the inlet of the first heat exchange fluid channel is connected to the main discharge pipe of the mother liquor from the lithium hexafluorophosphate crystallization vessel, and the outlet of the first heat exchange fluid channel is connected to the mother liquor tank. A refrigerant intermediate tank, the hot end outlet of which is connected to the inlet of the second heat exchange fluid channel of the heat exchanger device, and the outlet of the second heat exchange fluid channel of the heat exchanger device is connected to the cold end inlet of the refrigerant intermediate tank. The condenser has its cold end outlet connected to the refrigerant inlet of the condenser and its refrigerant outlet connected to the hot end inlet of the refrigerant intermediate tank. as well as The fan has its inlet connected to the outside air, its outlet connected to the air inlet of the condenser, and its air outlet connected to the phosphorus pentachloride feeding room.

2. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 1, characterized in that, The refrigerant intermediate tank is equipped with a level transmitter and a first temperature transmitter.

3. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 1, characterized in that, The heat exchanger device includes multiple heat exchangers connected in sequence. Each heat exchanger includes a first heat exchange fluid channel and a second heat exchange fluid channel. The inlet of the first heat exchange fluid channel of each heat exchanger is connected to the main discharge pipe of a number of lithium hexafluorophosphate crystallization kettles. The outlet of the first heat exchange fluid channel of each heat exchanger is connected to one of a number of mother liquor tanks. The hot end outlet of the refrigerant intermediate tank is connected to the inlet of the second heat exchange fluid channel of the last heat exchanger. The outlet of the second heat exchange fluid channel of the next heat exchanger is connected to the inlet of the second heat exchange fluid channel of the previous heat exchanger. The outlet of the second heat exchange fluid channel of the first heat exchanger is connected to the cold end inlet of the refrigerant intermediate tank.

4. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 3, characterized in that, Each heat exchanger is equipped with a second temperature transmitter at the outlet of the first heat exchange fluid channel.

5. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 1, characterized in that, It also includes a first refrigerant circulation pump, and the hot end outlet of the refrigerant intermediate tank is connected to the inlet of the second heat exchange fluid channel of the heat exchanger device via the first refrigerant circulation pump.

6. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 5, characterized in that, The outlet of the first refrigerant circulation pump is connected to the first return port of the refrigerant intermediate tank via the first return valve and the first return pipe.

7. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 5, characterized in that, The first refrigerant circulation pump is equipped with a first shut-off valve at its inlet, a second shut-off valve at its outlet, a first drain valve at its inlet, and a first pressure transmitter at its outlet.

8. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 1, characterized in that, It also includes a second refrigerant circulation pump, and the cold end outlet of the refrigerant intermediate tank is connected to the refrigerant inlet of the condenser via the second refrigerant circulation pump.

9. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 8, characterized in that, The outlet of the second refrigerant circulation pump is connected to the second return port of the refrigerant intermediate tank via the second return valve and the second return pipe.

10. The system for recovering scattered cryogenic liquid cold energy using a heat exchange device according to claim 9, characterized in that, The inlet of the second refrigerant circulation pump is equipped with a third shut-off valve, the outlet of the second refrigerant circulation pump is equipped with a fourth shut-off valve, the inlet of the second refrigerant circulation pump is equipped with a second drain valve, and the outlet of the second refrigerant circulation pump is equipped with a second pressure transmitter.

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