Nylon chip production waste heat recycling system

Abstract

The utility model provides a polyamide chip production waste heat recycling system. The polyamide chip production waste heat recycling system comprises a desalted water storage tank, a distribution pump, a first valve, a second valve, a three-way valve, a third valve, a fourth valve, a plate heat exchanger, a shell-and-tube heat exchanger, a partition plate heat exchanger, a first temperature transmitter, a liquid level transmitter, a kettle type reboiler, a desalted water conveying pump and a controller. A desalted water supplementing link in the production process is utilized, normal-temperature desalted water is conveyed to heat exchangers installed according to the high-low sequence of the temperature of discharged substances, discharged waste heat is recycled, the original mode that the temperature of a gas-state heating medium is adjusted through a fan is changed, temperature adjustment and control are matched after waste heat recycling, and the energy consumption is reduced. And the temperature of the desalted water is stabilized within a required range.

Description

Technical Field

[0001] This utility model relates to a waste heat recovery and reuse system for nylon chip production. Background Technology

[0002] The production process of nylon chips involves the release of a significant amount of heat and the heating of various media, such as steam from the reactor, condensate from the extraction water recovery process, and the cooling of the gaseous heat medium using fans. This heat is directly released into wastewater and the atmosphere, representing a waste of resources. Furthermore, the demineralized water used in the production process needs to be heated to approximately 90 degrees Celsius using steam.

[0003] Existing technologies utilize secondary energy source steam for heating, but the conversion efficiency of secondary energy is low, resulting in energy waste. Furthermore, during the production of nylon chips, steam is emitted from the reactor, and the condensate from the extraction water recovery process involves direct energy waste during the temperature regulation of the gaseous heat medium. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a waste heat recovery and reuse system for nylon chip production. By utilizing the demineralized water replenishment process in the production process, the demineralized water at room temperature is transported to heat exchangers installed in order of decreasing exhaust temperature to recover the exhaust waste heat. This changes the original method of regulating the temperature of the gaseous heat medium by a fan. After recovering the waste heat, temperature regulation and control are used to stabilize the temperature of the demineralized water within the required range.

[0005] This utility model is implemented as follows: a waste heat recovery and reuse system for nylon chip production, comprising: a demineralized water storage tank, a distribution pump, a first valve, a second valve, a three-way valve, a third valve, a fourth valve, a plate heat exchanger, a shell-and-tube heat exchanger, a diaphragm heat exchanger, a first temperature transmitter, a level transmitter, a kettle reboiler, a demineralized water transfer pump, and a controller.

[0006] The demineralized water storage tank is connected to one end of the first valve, one end of the second valve, and the inlet of the plate heat exchanger via a distribution pump. The outlet of the plate heat exchanger is connected to the inlet of the shell-and-tube heat exchanger. The outlet of the shell-and-tube heat exchanger is connected to the inlet of the diaphragm heat exchanger and one end of the third valve via a three-way valve. The outlet of the diaphragm heat exchanger is connected to one end of the third valve. The plate heat exchanger is used to recover the heat from the extraction of water by caprolactam. The shell-and-tube heat exchanger is used to recover the heat from the process steam exhaust pipe of the reactor. The diaphragm heat exchanger is used to recover the heat from the gaseous heat transfer medium used for insulation in the reactor jacket.

[0007] The reboiler is equipped with a low-pressure steam inlet, a steam condensate outlet, a demineralized water inlet, and a demineralized water outlet; the other ends of the first valve, the second valve, and the third valve are all connected to the demineralized water inlet, and the demineralized water outlet is connected to the demineralized water delivery pump; the first temperature transmitter is used to measure the temperature of the demineralized water at the demineralized water outlet; a fourth valve is provided at the low-pressure steam inlet; and the level transmitter is located inside the reboiler.

[0008] The controller is electrically connected to the first valve, the third valve, the fourth valve, the level transmitter, the first temperature transmitter, the distribution pump, and the demineralized water transfer pump, respectively.

[0009] Furthermore, it also includes a second temperature transmitter. The diaphragm heat exchanger is provided with a heat medium outlet, and the second temperature transmitter is located at the heat medium outlet. The controller is electrically connected to the second temperature transmitter and the three-way valve.

[0010] The advantages of this utility model are as follows: This utility model provides a waste heat recovery and reuse system for nylon chip production. The demineralized water is exchanged with the extraction water recovery system and other condensate with high residual heat in the nylon chip production process. The temperature is further increased by replacing the heat exchanger in the original gaseous heat medium regulation system that relies on fans to cool and dissipate heat. This reduces the use of steam energy, maximizes the utilization of waste heat, increases the energy utilization rate of production, and reduces production costs. Attached Figure Description

[0011] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0012] Figure 1 This is a schematic diagram of the principle of a waste heat recovery and reuse system for nylon chip production according to this utility model. Detailed Implementation

[0013] Please see Figure 1 As shown, this utility model discloses a waste heat recovery and reuse system for nylon chip production, comprising: a demineralized water storage tank 101, a distribution pump 102, a first valve 103, a second valve 104, a three-way valve 105, a third valve 106, a fourth valve 107, a plate heat exchanger 108, a shell-and-tube heat exchanger 109, a diaphragm heat exchanger 110, a first temperature transmitter 111, a level transmitter 112, a kettle reboiler 113, a demineralized water transfer pump 114, and a controller (not shown in the figure). The controller is a microcontroller or a computer and can be purchased on the market.

[0014] The demineralized water storage tank 101 is connected to one end of the first valve 103, one end of the second valve 104, and the inlet of the plate heat exchanger 108 via a distribution pump 102. The outlet of the plate heat exchanger 108 is connected to the inlet of the shell-and-tube heat exchanger 109. The outlet of the shell-and-tube heat exchanger 109 is connected to the inlet of the diaphragm heat exchanger 110 and one end of the third valve 106 via a three-way valve 105. The outlet of the diaphragm heat exchanger 110 is connected to one end of the third valve 106. The plate heat exchanger 108 is used to recover the heat from caprolactam extraction of water; the tube heat exchanger 109 is used to recover the heat from the steam exhaust pipe of the reactor process; the baffle heat exchanger 110 is used to recover the heat from the gaseous heat medium in the reactor jacket insulation, collecting the heat of the gaseous heat medium (HVP) so that cooling by a fan is no longer required when using the gaseous heat medium (HVP); the plate heat exchanger 108 and the tube heat exchanger 109 can collect waste heat from other systems for heating the demineralized water;

[0015] The reboiler 113 is provided with a low-pressure steam inlet 1131, a steam condensate outlet 1132, a demineralized water inlet 1133, and a demineralized water outlet 1134. The other ends of the first valve 103, the second valve 104, and the third valve 106 are all connected to the demineralized water inlet 1133. The demineralized water outlet 1134 is connected to the demineralized water transfer pump 114. The first temperature transmitter 111 is used to measure the temperature of the demineralized water at the demineralized water outlet 1134. A fourth valve 107 is provided at the low-pressure steam inlet 1131. The level transmitter 112 is located inside the reboiler 113. The level transmitter 112 obtains the liquid level inside the reboiler 113. When the level is too high or too low, the opening degree of the third valve 106 and the first valve 103 can be controlled by the controller to control the liquid level.

[0016] The controller is electrically connected to the first valve 103, the third valve 106, the fourth valve 107, the level transmitter 112, the first temperature transmitter 111, the distribution pump 102, and the demineralized water transfer pump 114.

[0017] When the temperature of the first temperature transmitter 111 is higher than the required temperature, the second valve 104 is opened, allowing low-temperature demineralized water to be added to the reboiler 113, thus lowering the temperature inside the reboiler 113. If the temperature of the first temperature transmitter 111 is lower than the required temperature, the controller controls the fourth valve 107 to supplement heating with steam. The demineralized water heated to the set temperature is then transported to the required location via the demineralized water transfer pump 114. Low-pressure steam SLP enters the reboiler 113 through the low-pressure steam inlet 1131 to heat the demineralized water. As the temperature drops, condensate is formed and discharged from the steam condensate (SCL) outlet 1132.

[0018] In this embodiment, preferably, a second temperature transmitter 115 is also included. The partition heat exchanger 110 is provided with a heat medium outlet 1101. The second temperature transmitter 115 is located at the heat medium outlet 1101. The controller is electrically connected to the second temperature transmitter 115 and the three-way valve 105. The temperature of the heat medium at the heat medium outlet 1101 is obtained through the second temperature transmitter 115. Then, the controller adjusts the three-way valve 105 to control the temperature of the gaseous heat medium passing through the partition heat exchanger 110, thereby obtaining the required temperature.

[0019] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0020] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A system for recycling waste heat from production of nylon chips, characterized in that: The application relates to a desalted water recovery system. The desalted water tank is connected with one end of the first valve, one end of the second valve and the inlet of the plate heat exchanger through the distribution pump, the outlet of the plate heat exchanger is connected with the inlet of the column heat exchanger, the outlet of the column heat exchanger is connected with the inlet of the partition heat exchanger and one end of the third valve through the three-way valve, and the outlet of the partition heat exchanger is connected with one end of the third valve; the plate heat exchanger is used for recovering the heat of lactam extraction water; the column heat exchanger is used for recovering the heat in the reaction kettle process steam discharge pipe; and the partition heat exchanger is used for recovering the heat of the reaction kettle jacket heat preservation gaseous heat medium. The kettle reboiler is provided with a low-pressure steam inlet, a steam condensate water outlet, a desalted water inlet and a desalted water outlet; the other end of the first valve, the other end of the second valve and the other end of the third valve are connected with the desalted water inlet, the desalted water outlet is connected with the desalted water conveying pump, and the first temperature transmitter is used for measuring the temperature of the desalted water at the desalted water outlet; the fourth valve is arranged at the low-pressure steam inlet; and the liquid level transmitter is arranged in the kettle reboiler. The controller is electrically connected with the first valve, the third valve, the fourth valve, the liquid level transmitter, the first temperature transmitter, the distribution pump and the desalted water conveying pump. The application further relates to a second temperature transmitter, a heat medium outlet is arranged on the partition heat exchanger, the second temperature transmitter is arranged at the heat medium outlet, and the controller is electrically connected with the second temperature transmitter and the three-way valve.

2. The system for recycling waste heat from the production of nylon chips according to claim 1, characterized in that: ​

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