A waste heat recovery device for a lithium bromide refrigeration plant

Abstract

The utility model relates to the technical field of waste heat recovery, and disclose a kind of waste heat recovery device of lithium bromide refrigeration equipment, to solve the shortcoming that heat exchange waste heat is not easy to multiple recycling in production process in prior art.The utility model is through waste heat recovery tower, acetylene hydrochlorination reactor, lithium bromide unit, production equipment, low temperature water discharge pipe, shunt pipe, return pipe, shock mount, corrugated compensator etc., using the hot water of acetylene hydrochlorination reactor shell course removal reaction system produces low pressure steam, with the water in waste heat recovery tower carries out one heat exchange, drives lithium bromide unit to prepare low temperature water, for production equipment heat exchange, and excess return water re-enters waste heat recovery tower recycling;Steam pipe gradient design and gas-liquid separator are used to reduce heat transfer resistance, multiple reflux paths are used to achieve efficient recovery of low temperature water, and shock mount and corrugated compensator are used to enhance the stability of the pipeline, improve the waste heat recovery rate and equipment life.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, and in particular to a waste heat recovery device for a lithium bromide refrigeration equipment. Background Technology

[0002] The vinyl chloride workshop of the resin plant uses lithium bromide + centrifugal refrigeration process to prepare 7°C water required for heat exchange in the production system. The heat used by the lithium bromide system comes from the heat released by the hydrochlorination reaction of acetylene.

[0003] Chinese Patent Publication No. CN212139476U discloses a cold storage waste heat recovery system combined with a lithium bromide absorption chiller. The system includes a lithium bromide absorption chiller unit, with its high-temperature gas outlet connected to a compressor exhaust pipe. Two branch pipes are installed on the compressor exhaust pipe; the first branch pipe is connected to the condenser gas inlet. A main valve is installed on the compressor exhaust pipe, and control valves are also installed on the first and second branch pipes, respectively, to achieve waste heat recovery.

[0004] Regarding the above and existing related technologies, the inventors believe that the following defects often exist: the device sends the primary steam condensate used by the furfural wastewater evaporator to a pressure vessel for de-cooling and depressurization to form saturated water vapor at room temperature, which is then used in the lithium bromide refrigeration unit to achieve a primary steam cycle. The waste heat recovery and utilization rate during the cycle is low, which easily leads to the waste of waste heat after heat exchange in the wastewater evaporator and the lithium bromide refrigeration unit. Therefore, there is room for improvement. Utility Model Content

[0005] The technical problem to be solved by this utility model is that the existing technology does not make it easy to repeatedly recycle the waste heat from the heat exchange process in the production process. To address this, we propose a waste heat recovery device for lithium bromide refrigeration equipment.

[0006] To achieve the above objectives, this application adopts the following technical solution: a waste heat recovery device for a lithium bromide refrigeration equipment, comprising: a waste heat recovery tower, the bottom end of which is connected to the hot water inlet of an acetylene hydrochlorination reactor via a steam pipe; the hot water outlet of the acetylene hydrochlorination reactor is connected to the steam inlet in the middle of the waste heat recovery tower via a steam pipe; the steam pipe is configured as an upwardly inclined structure with a slope of not less than 5°; a gas-liquid separator is installed on the side of the steam pipe near the waste heat recovery tower; the bottom end of the gas-liquid separator is connected to the bottom end of the waste heat recovery tower via a water return pipe; the bottom end of the waste heat recovery tower is connected to the hot water inlet of the lithium bromide unit via a hot water pipe A; and the hot water outlet of the lithium bromide unit is connected to... The hot water return pipe is connected to the return main pipe, and one end of the return main pipe is connected to the hot water return port in the middle of the waste heat recovery tower. Circulation pump A is installed on hot water pipe A, hot water pipe B, and the return main pipe. Temperature sensors are installed on the pipes connected to the waste heat recovery tower, the acetylene hydrochlorination reactor, and the lithium bromide unit. The temperature sensor on hot water pipe B is located upstream of circulation pump A on hot water pipe B. Circulation pump A on the steam pipe is installed at a low position. Vibration damping supports are installed at equal intervals on hot water pipe A, hot water pipe B, hot water return pipe, and the return main pipe. Corrugated compensators are installed at equal intervals on hot water pipe A, hot water pipe B, hot water return pipe, and the return main pipe. Vibration damping supports and corrugated compensators are installed alternately.

[0007] Preferably, the steam pipe is equipped with a self-regulating pressure regulating valve, and the steam pipe is made of 80mm thick aluminum silicate fiber felt + aluminum sheet protective layer, and the outer surface temperature after insulation is ≤50℃.

[0008] Preferably, the top of the waste heat recovery tower is connected to an empty vent pipe, one end of which is equipped with a condenser. The bottom end of the condenser is connected to the liquid inlet in the middle of the waste heat recovery tower through a liquid replenishment pipe, and a circulation pump C is installed on the liquid replenishment pipe.

[0009] Preferably, one end of the lithium bromide generator is connected to a low-temperature water drain pipe, and one end of the low-temperature water drain pipe is connected to multiple branch pipes, one end of each branch pipe being connected to the low-temperature water inlet of the production equipment.

[0010] Preferably, the high-temperature water outlets of the production equipment are all connected to the return pipe through pipelines. One end of the return pipe is connected to the return port of the lithium bromide unit, and the other side of the return pipe is diverted to the interior of the main return pipe.

[0011] Preferably, a circulating pump B is installed on both the low-temperature water drain pipe and the return pipe, and an electromagnetic flow meter and an electric flow regulating valve are installed on the return pipe.

[0012] The technical effects and advantages of this utility model are as follows:

[0013] In this invention, hot water from the shell side of the acetylene hydrochlorination reactor is removed from the reaction system to generate low-pressure steam, which performs a primary heat exchange on the water flow in the waste heat recovery tower. This steam is then used for the preparation of low-temperature water in the lithium bromide unit, allowing the low-temperature water from the lithium bromide unit to perform a primary heat exchange on the production equipment. Combined with the return main pipe, excess return water enters the waste heat recovery tower for reheating, thus achieving multiple waste heat cycles throughout the vinyl chloride production process. By using condensers, replenishment pipes, and other components, excess heat steam in the acetylene hydrochlorination reactor is condensed and returned to the interior of the acetylene hydrochlorination reactor, further improving the waste heat recovery rate while reducing water waste.

[0014] In this invention, the slope design of the steam pipe and the cooperation of the gas-liquid separator are used to reduce resistance and vibration during the gas-liquid transportation process and improve heat transfer efficiency. The design of multiple return paths, such as the return main pipe and the branch pipe, enables flexible distribution and efficient recovery of low-temperature water in the lithium bromide unit. The use of shock-absorbing brackets and corrugated compensators enhances the stability of the pipeline and extends its service life. Attached Figure Description

[0015] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts:

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0017] Figure 2 This is a schematic diagram of the distributed three-dimensional structure of the lithium bromide generator unit according to this utility model;

[0018] Figure 3 This is a three-dimensional structural diagram of the low-temperature water pipe distribution of this utility model;

[0019] Figure 4 This is a three-dimensional structural diagram of the empty discharge pipe distribution of this utility model;

[0020] Figure 5 This is a three-dimensional structural diagram of the steam pipe distribution of this utility model.

[0021] Legend: 1. Waste heat recovery tower; 2. Acetylene hydrochlorination reactor; 3. Lithium bromide unit; 4. Production equipment; 51. Low temperature water drain pipe; 52. Diverter pipe; 53. Return pipe; 6. Vibration damping bracket; 7. Corrugated compensator; 8. Circulation pump A; 9. Vent pipe; 91. Condenser; 92. Make-up pipe; 93. Circulation pump C; 10. Circulation pump B; 11. Hot water pipe A; 12. Hot water pipe B; 13. Hot water return pipe; 14. Return main pipe; 15. Steam pipe; 151. Gas-liquid separator; 152. Water return pipe. Detailed Implementation

[0022] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0023] Reference Figure 1 , Figure 2 and Figure 5 As shown, this utility model provides a technical solution: a waste heat recovery device for a lithium bromide refrigeration equipment, comprising: a waste heat recovery tower 1, the bottom end of which is connected to the hot water inlet of an acetylene hydrochlorination reactor 2 via a steam pipe 15, the hot water outlet of the acetylene hydrochlorination reactor 2 being connected to the steam inlet in the middle of the waste heat recovery tower 1 via a steam pipe 15, the steam pipe 15 being configured with an upwardly inclined structure with a slope of not less than 5°, a gas-liquid separator 151 installed on the side of the steam pipe 15 near the waste heat recovery tower 1, the bottom end of the gas-liquid separator 151 being connected to the bottom end of the waste heat recovery tower 1 via a water return pipe 152, the bottom end of the waste heat recovery tower 1 being connected to the hot water inlet of a lithium bromide unit 3 via a hot water pipe A11, and the hot water outlet of the lithium bromide unit 3 being connected to the reflux system via a hot water return pipe 13. The main pipe 14 and the return main pipe 14 are connected at one end to the hot water return port in the middle of the waste heat recovery tower 1. Circulation pumps A8 are installed on hot water pipes A11, B12 and the return main pipe 14. Temperature sensors are installed on the pipes connecting the waste heat recovery tower 1, the acetylene hydrochlorination reactor 2 and the lithium bromide unit 3. The temperature sensor on hot water pipe B12 is located upstream of the circulation pump A8 on hot water pipe B12. The circulation pump A8 on the steam pipe 15 is installed at a low position. Vibration damping brackets 6 are installed at equal intervals on hot water pipes A11, B12, hot water return pipe 13 and the return main pipe 14. Corrugated compensators 7 are installed at equal intervals on hot water pipes A11, B12, B13 and the return main pipe 14. Vibration damping brackets 6 and corrugated compensators 7 are installed alternately.

[0024] The upward-sloping structure of the steam pipe 15 allows steam in the acetylene hydrochlorination reactor 2 to smoothly enter the reactor under evaporation, reducing resistance. The steam outlet pressure of the acetylene hydrochlorination reactor 2 is approximately 0.2 MPa gauge pressure, and the operating pressure of the waste heat recovery tower is 0.15 MPa. The pressure difference enables the steam to be transported under its own pressure, thereby allowing the water in the waste heat recovery tower 1 to exchange heat and be heated. Then, using the hot water pipe A11, the hot water is used as the heat source for the lithium bromide unit 3 to produce low-temperature water, which is then used to exchange heat with the production equipment 4. The return main pipe 14 is used to further circulate the heat source water back to the acetylene hydrochlorination reactor 2 for further heat exchange, realizing the perpetual operation of the lithium bromide unit 3. The vibration damping bracket 6 and the corrugated compensator 7 are used to compensate for the expansion and contraction displacement of the pipeline caused by temperature changes, reduce the stress of key pipelines, absorb pipeline vibration, and improve the service life of the pipeline.

[0025] The steam pipe 15 is equipped with a self-regulating pressure regulating valve. The steam pipe 15 is protected by an 80mm thick aluminum silicate fiber felt and an aluminum sheet. After insulation, the outer surface temperature is ≤50℃.

[0026] The pressure difference between the acetylene hydrochlorination reactor 2 and the waste heat recovery tower 1 is used to achieve the self-flow of gas and liquid, reducing the use of electrical equipment. At the same time, the material of the steam pipe 15 is used to reduce the contact temperature of the surface of the steam pipe 15 and prevent accidental injury.

[0027] Reference Figure 4 As shown in this embodiment: the top of the waste heat recovery tower 1 is connected to an empty vent pipe 9, one end of the empty vent pipe 9 is equipped with a condenser 91, the bottom end of the condenser 91 is connected to the liquid replenishment port in the middle of the waste heat recovery tower 1 through a liquid replenishment pipe 92, and a circulation pump C93 is installed on the liquid replenishment pipe 92.

[0028] The condenser 91 is used to further recover the waste heat of the excess steam in the acetylene hydrochlorination reactor 2. At the same time, the condensation method is used to replenish the hot water flow in the acetylene hydrochlorination reactor 2 in a timely manner, so as to ensure the fluidity of the entire heat cycle.

[0029] Reference Figure 3 As shown in this embodiment: one end of the lithium bromide unit 3 is connected to a low-temperature water drain pipe 51, and one end of the low-temperature water drain pipe 51 is connected to multiple branch pipes 52. One end of each branch pipe 52 is connected to the low-temperature water inlet of the production equipment 4.

[0030] The high-temperature water outlets of production equipment 4 are all connected to the return pipe 53 through pipelines. One end of the return pipe 53 is connected to the return port of the lithium bromide unit 3, and the other side of the return pipe 53 is diverted to the inside of the return main pipe 14.

[0031] The low-temperature water from the lithium bromide unit 3 is used to facilitate heat exchange with different production equipment 4, which can be raw material preheaters, product refining equipment, etc. in the production process. The low-temperature water can be flexibly distributed and recycled by using the return pipe 53 and the return main pipe 14.

[0032] Both the low-temperature water drain pipe 51 and the return pipe 53 are equipped with a circulating pump B10, and both the return pipe 53 is equipped with an electromagnetic flow meter and an electric flow regulating valve.

[0033] By using electromagnetic flow meters and electric flow regulating valves, the water flow rate can be increased in a timely manner according to the usage of production equipment 4, thus avoiding waste.

[0034] Working Principle: The user activates and adjusts the flow rates of circulating pumps A8 and B10 on each pipeline via a temperature sensor. When hot water in the shell side of the acetylene hydrochlorination reactor 2 is removed from the reaction system to generate low-pressure steam, under the differential pressure between the waste heat recovery tower 1 and the acetylene hydrochlorination reactor 2, it automatically flows through steam pipe 15 to the waste heat recovery tower 1. The gas-liquid separator 151 separates the water from the steam, allowing heat to enter the waste heat recovery tower 1. The water flows to the bottom of the waste heat recovery tower 1 and is then transported through hot water pipe B12 to the interior of the acetylene hydrochlorination reactor 2 for circulating heat absorption. When the heat level in the acetylene hydrochlorination reactor 2 is high, venting is performed using the vent pipe 9. Here, the condenser 91 and the replenishment pipe 92 work together to vent this part... Waste heat is recovered in a secondary manner. The water in the acetylene hydrochlorination reactor 2 is heated by heat exchange. The high-temperature water enters the reactor of the lithium bromide unit 3 through the hot water pipe A11, and then flows back to the waste heat recovery tower 1 for circulation heating through the hot water return pipe 13 and the return main pipe 14. The lithium bromide unit 3 discharges low-temperature water from the low-temperature water drain pipe 51, and then distributes it to different production equipment 4 through the branch pipe 52 for heat exchange. The water that has undergone heat exchange in the production equipment 4 flows back to the lithium bromide unit 3 through the return pipe 53 for use. A portion of the water flows into the return main pipe 14 for circulation. The flow rate in each branch pipe is controlled by the flow sensor and circulation pumps A8 and B10 to ensure the orderly operation of the hot and cold circulation.

[0035] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. A waste heat recovery device for a lithium bromide refrigeration equipment, characterized in that, include: The waste heat recovery tower has its bottom end connected to the hot water inlet of an acetylene hydrochlorination reactor via a steam pipe. The hot water outlet of the acetylene hydrochlorination reactor is connected to the steam inlet in the middle of the waste heat recovery tower via a steam pipe. The steam pipe is designed with an upwardly inclined structure with a slope of not less than 5°. A gas-liquid separator is installed on the side of the steam pipe closest to the waste heat recovery tower. The bottom end of the gas-liquid separator is connected to the bottom end of the waste heat recovery tower via a water return pipe. The bottom end of the waste heat recovery tower is connected to the hot water inlet of a lithium bromide unit via hot water pipe A. The hot water outlet of the lithium bromide unit is connected to a return main pipe via a hot water return pipe. One end of the return main pipe is connected to the waste heat recovery tower. The hot water return ports in the middle of the heat recovery tower are connected. Circulation pump A is installed on hot water pipe A, hot water pipe B, and the return main pipe. Temperature sensors are installed on the pipes connecting the waste heat recovery tower, the acetylene hydrochlorination reactor, and the lithium bromide unit. The temperature sensor on hot water pipe B is located upstream of circulation pump A on hot water pipe B. Circulation pump A on the steam pipe is installed at a low position. Vibration damping supports are installed at equal intervals on hot water pipe A, hot water pipe B, hot water return pipe, and the return main pipe. Corrugated compensators are installed at equal intervals on hot water pipe A, hot water pipe B, hot water return pipe, and the return main pipe. The vibration damping supports and corrugated compensators are installed alternately.

2. The waste heat recovery device for the lithium bromide refrigeration equipment according to claim 1, characterized in that: The steam pipe is equipped with a self-regulating pressure regulating valve. The steam pipe is made of 80mm thick aluminum silicate fiber felt + aluminum sheet protective layer, and the outer surface temperature is ≤50℃ after heat preservation.

3. The waste heat recovery device for the lithium bromide refrigeration equipment according to claim 1, characterized in that: The top of the waste heat recovery tower is connected to an empty vent pipe, one end of which is equipped with a condenser. The bottom end of the condenser is connected to the liquid replenishment port in the middle of the waste heat recovery tower through a liquid replenishment pipe, and a circulation pump C is installed on the liquid replenishment pipe.

4. The waste heat recovery device for the lithium bromide refrigeration equipment according to claim 1, characterized in that: One end of the lithium bromide generator is connected to a low-temperature water drain pipe, and one end of the low-temperature water drain pipe is connected to multiple branch pipes, one end of each branch pipe being connected to the low-temperature water inlet of the production equipment.

5. The waste heat recovery device for the lithium bromide refrigeration equipment according to claim 4, characterized in that: The high-temperature water outlets of the production equipment are all connected to the return pipe via pipelines. One end of the return pipe is connected to the return port of the lithium bromide unit, and the other side of the return pipe is branched into the interior of the main return pipe.

6. The waste heat recovery device for the lithium bromide refrigeration equipment according to claim 4, characterized in that: Both the low-temperature water drain pipe and the return pipe are equipped with a circulation pump B, and both the return pipe and the return pipe are equipped with an electromagnetic flow meter and an electric flow regulating valve.

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