Recovery and utilization system of high-pressure condensate from PTA polyester integrated equipment

Abstract

The present invention discloses a system for recycling high-pressure condensate from a PTA polyester integrated device, relating to the field of heat energy recycling technology. The system comprises a polyester condensate main pipe, the polyester condensate main pipe being connected to a flash evaporation system and a pressure stabilization system via two pipes, a heat exchanger and a cold water tank being provided on one side of the polyester condensate main pipe, the cold water tank being connected to the heat exchanger via a second pump group, the heat exchanger being further connected to a hot water tank via a pipe, and the heat exchanger being connected to the polyester condensate main pipe via a polyester condensate branch pipe. The present invention adds a set of heat exchangers outside the flash evaporation system and the pressure stabilization system, allowing the two polyester return water pumps to operate at low loads normally, reducing risks. If one polyester return water pump experiences a problem, the other pump can be fully loaded. Alternatively, the two polyester return water pumps can be used in a standby mode, with one pump being fully loaded and the other pump activated in the event of a problem. This allows for greater flexibility in polyester return water regulation and effectively ensures the safety of the polyester return water pump group.

Description

Technical Field

[0001] The invention relates to the technical field of heat energy recovery and utilization, in particular to a recovery and utilization system of high-pressure condensate of PTA polyester integrated equipment. Background Art

[0002] Polyester is a general term for polymers obtained by the condensation of polyols and polyacids. The production of polyester industry consumes a lot of heat energy. The polyester process usually uses heat transfer oil to provide this heat. The heat of the heat transfer oil can be obtained by heat exchange with steam through large steam heat exchangers. After heat exchange with heat transfer oil, high-pressure steam is converted into high-temperature and high-pressure condensate, which contains huge heat and potential energy.

[0003] The traditional hot standby method is to use flash evaporation to produce medium and low pressure steam, and the condensate is sent back to the deaerator. How to return this part of high temperature and high pressure condensate to the steam-water cycle of thermal power plant-polyester is very critical for efficient energy utilization. In the existing polyester high pressure condensate recovery system, two polyester return water pumps transport the condensate to the mixed water heat exchanger and then to the boiler. The pressure stabilizing system on it is in normal use. The flash evaporation system is only used when there is an abnormality in the pressure stabilizing system. The two polyester return water pumps transport the condensate to the mixed water heat exchanger and then to the boiler. When one polyester return water pump has a problem, the other cannot meet the use requirements. The polyester condensate accumulates, the liquid level in the pressure stabilizing tank rises, and the condensate reflux is not smooth. Only then will the flash evaporation system be put into use. The design is not flexible enough, which affects the polyester spinning production. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems in the prior art that the original system design for recovering polyester high-pressure condensate is not flexible enough, which may lead to excessive accumulation of polyester condensate, rising liquid level in the pressure-surge tank and poor condensate reflux, and to propose a recovery and utilization system for high-pressure condensate of PTA polyester integrated equipment.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a recycling system for high-pressure condensate of a PTA polyester integrated equipment, comprising a polyester condensate main pipe, wherein the polyester condensate main pipe is connected to a flash evaporation system and a pressure stabilization system through two pipes respectively, a heat exchanger and a cold water tank are provided on one side of the polyester condensate main pipe, the cold water tank is connected to the heat exchanger through a second pump group, the heat exchanger is also connected to a hot water tank through a pipe, the heat exchanger is connected to the polyester condensate main pipe through a polyester condensate branch pipe, the heat exchanger is connected to an expansion tank through a pipe, and the expansion tank is connected to a deaerator through a first pump group.

[0006] As a further description of the above technical solution:

[0007] The upper portion of the expansion vessel is connected with a continuous row of pipes and valves, and the lower portion of the expansion vessel is connected with a fixed row of pipes and valves.

[0008] As a further description of the above technical solution:

[0009] The polyester condensate main pipe and the polyester condensate branch pipes are welded.

[0010] As a further description of the above technical solution:

[0011] The pump group 1 is composed of valves, pipelines and pumps, and the inlets and outlets of the valves, pipelines and pumps are connected in sequence through flanges.

[0012] As a further description of the above technical solution:

[0013] A flange is also provided on the pipeline between the heat exchanger and the hot water tank, and the flange is connected to the pipeline via the flange.

[0014] The present invention has the following beneficial effects:

[0015] 1. Compared with the existing technology, the high-pressure condensate recovery and utilization system of the PTA polyester integrated equipment, through the mutual cooperation between the polyester condensate main pipe, polyester condensate branch pipe, heat exchanger, expansion tank, cold water tank, deaerator and hot water tank, adds a group of heat exchangers outside the flash evaporation system and the pressure stabilization system. The two polyester return water pumps can normally operate at less than full load to reduce risks. When one polyester return water pump has a problem, the other pump can also be fully loaded; or the two polyester return water pumps are used in one standby and the other in use, the one in use is fully loaded, and the other is started when a problem occurs, making the polyester return water regulation more flexible and effectively ensuring the safety of the polyester return water pump group.

[0016] 2. Compared with the existing technology, the high-pressure condensate recovery and utilization system of the PTA polyester integrated equipment cooperates with the heat exchanger, cold water tank and hot water tank. After the polyester condensate is heat exchanged, the hot water flows to the hot water tank. At this time, the hot water in the hot water tank can be used as bathing water, which can be used in the factory or taken to the bathhouse, creating higher benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of the high-pressure condensate recovery and utilization system of the PTA polyester integrated equipment proposed by the present invention.

[0018] Legend:

[0019] 1. Polyester condensate main pipe; 2. Flash evaporation system; 3. Pressure stabilization system; 4. Polyester condensate branch pipe; 5. Heat exchanger; 6. Expansion tank; 7. Pump group 1; 8. Cold water tank; 9. Pump group 2; 10. Deaerator; 11. Hot water tank. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] Reference Figure 1 The present invention provides a PTA polyester integrated equipment high-pressure condensate recovery and utilization system: comprising a polyester condensate main pipe 1, the polyester condensate main pipe 1 is respectively connected to a flash evaporation system 2 and a pressure stabilization system 3 through two pipes, a heat exchanger 5 and a cold water tank 8 are provided on one side of the polyester condensate main pipe 1, the cold water tank 8 is connected to the heat exchanger 5 through a second pump group 9, the heat exchanger 5 is also connected to a hot water tank 11 through a pipe, the heat exchanger 5 is connected to the polyester condensate main pipe 1 through a polyester condensate branch pipe 4, and the polyester condensate main pipe 1 and the polyester condensate branch pipe 4 are welded.

[0022] Among them, the heat exchanger 5 is connected to the expansion tank 6 through a pipeline, the expansion tank 6 is connected to the deaerator 10 through a pump group 7, the upper part of the expansion tank 6 is connected to a continuous row of pipes and valves, and the lower part of the expansion tank 6 is connected to a fixed row of pipes and valves. A group of heat exchangers 5 is added outside the flash evaporation system 2 and the pressure stabilizing system 3. The two polyester return water pumps can normally operate at less than full load to reduce risks. When a polyester return water pump has a problem, the other pump can also be fully loaded; or the two polyester return water pumps are used in one standby and the other is fully loaded. When a problem occurs, the other is immediately started to prevent the accumulation of polyester condensate, the rise of the liquid level in the pressure stabilizing tank, and the poor condensate reflux. This makes the polyester return water regulation more flexible and effectively ensures the safety of the polyester return water pump group.

[0023] Furthermore, the pump group 7 is composed of valves, pipes and pumps. The inlets and outlets of the valves, pipes and pumps are connected in sequence by flanges. The flange connection makes them disassembled when necessary to clean impurities in the pipes. A flange is also provided on the pipe between the heat exchanger 5 and the hot water tank 11. The flange is connected to the pipe by a flange. Since scale will be generated when heating domestic water, the flange connection makes it more convenient to disassemble and clean the internal scale.

[0024] The present invention can be explained through the following operation mode:

[0025] During use, while the pressure stabilizing system 3 is operating normally, the high-temperature polyester condensate in the polyester condensate main pipe 1 can also enter the heat exchanger 5 through the polyester condensate branch pipe 4, exchange heat with cold water in the heat exchanger 5, and then flow into the expansion tank 6. The steam in the expansion tank 6 enters the continuous exhaust to remove steam balance through the upper valve, and the water is recovered by the pump group 7 and enters the deaerator 10.

[0026] The cold water in the cold water tank 8 enters the heat exchanger 5 through the pump group 2 9. The cold water is converted into hot water after heat exchange with the high-temperature polyester condensate and flows to the hot water tank 11. The hot water in the hot water tank 11 can be used as bathing water, which can be used in the factory area or taken to the bathhouse to create higher benefits. The two polyester return water pumps are respectively connected to the heat exchanger 5 and the pressure stabilizing system 3, that is, the heat exchanger 5 and the pressure stabilizing system 3 work synchronously to realize the recovery and utilization of the heat energy of the high-temperature polyester condensate. After the pressure stabilizing system 3 is damaged, the heat exchanger 5 can still operate normally, making the polyester return water regulation more flexible and effectively ensuring the safety of the polyester return water pump group.

[0027] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A system for recycling high-pressure condensate of a PTA polyester integrated equipment, comprising a polyester condensate main pipe (1), wherein the polyester condensate main pipe (1) is connected to a flash evaporation system (2) and a pressure stabilization system (3) via two pipelines, and is characterized in that: A heat exchanger (5) and a cold water tank (8) are provided on one side of the polyester condensate main pipe (1); the cold water tank (8) is connected to the heat exchanger (5) via a second pump group (9); the heat exchanger (5) is also connected to a hot water tank (11) via a pipeline; the heat exchanger (5) is connected to the polyester condensate main pipe (1) via a polyester condensate branch pipe (4); the heat exchanger (5) is connected to an expansion tank (6) via a pipeline; the expansion tank (6) is connected to a deaerator (10) via a first pump group (7); The upper portion of the expansion container (6) is connected to a continuous row of pipes and valves, and the lower portion of the expansion container (6) is connected to a fixed row of pipes and valves; The polyester condensate main pipe (1) and the polyester condensate branch pipe (4) are welded; The pump group 1 (7) is composed of valves, pipelines and pumps, and the inlets and outlets of the valves, pipelines and pumps are connected in sequence through flanges.

2. The recycling system of high-pressure condensate of PTA polyester integrated equipment according to claim 1, characterized in that: A flange is also provided on the pipeline between the heat exchanger (5) and the hot water tank (11), and the flange is connected to the pipeline via the flange.

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