Industrial frozen brine conveying and circulating device capable of automatically stabilizing pressure

Abstract

The utility model discloses an industrial frozen brine conveying and circulating device capable of automatically stabilizing pressure, which comprises a brine circulating tank, a brine pump, a refrigerating unit and a heat exchanger which are sequentially connected through pipelines, and the heat exchanger is a tubular heat exchanger. In the operation process of an existing brine system, a rear-end heat exchanger frequently adjusts the opening degree of a brine valve in order to guarantee the material temperature, so that the water supply pressure of the brine system fluctuates, and related parts of the system are damaged or safety accidents occur. According to the utility model, the brine return pipe communicated with the brine circulating tank is arranged on the pipeline between the brine pump and the refrigerating unit, and the return regulating valve is arranged on the brine return pipe, so that the pressure of the system is ensured to be stable; and meanwhile, a pressure transmitter and a flow regulating valve are arranged on a pipeline for connecting the refrigerating unit with the shell pass of the heat exchanger, so that the operation pressure of the saline water system is convenient to monitor, and automatic pressure stabilization in the saline water conveying process is realized by utilizing a programmable logic controller (PLC).

Description

Technical Field

[0001] The utility model relates to the technical field of calcium carbide acetylene production, in particular to an industrial refrigerated brine conveying circulation device capable of automatically stabilizing voltage. Background Art

[0002] In current chemical production processes, the most common method for cooling is using chilled brine cryogenics. Brine cryogenics primarily utilize the phenomenon of freezing point depression, whereby the freezing point of a solution drops below that of pure water. In industrial chilled brine systems, water is typically mixed with specific salts (such as sodium chloride, calcium chloride, and ethylene glycol) in a specific proportion. The resulting brine solution begins to freeze at a lower temperature. This is because the salt, when dissolved in water, disrupts the hydrogen bonding network between water molecules, lowering the temperature required for ice crystal formation. The most commonly used cryogenic medium is brine at -35°C. The chilled brine cryogenic process involves preparing brine to a specific concentration in a circulation tank and then pumping it to a refrigeration unit using a brine pump. After being cooled by the refrigeration unit, the brine enters a chemical cryogenic heat exchanger for heat exchange. After the heat exchange is complete, the brine returns to the brine circulation tank through pipes, repeating the cycle to complete the cryogenic exchange in the chemical process.

[0003] During the operation of traditional cryogenic devices, the subsequent chemical cryogenic heat exchanger usually needs to install a regulating valve on the brine inlet pipeline to control the outlet temperature of the reaction materials. During operation, the brine flow rate is adjusted in real time according to the material temperature, resulting in large fluctuations in the brine pump outlet pressure. The brine supply pressure often exceeds or falls below the process index, leading to the following problems during the operation of the brine system:

[0004] 1. Excessive operating pressure in the brine system will cause damage to other subsequent heat exchangers. For example, graphite heat exchangers are widely used in chemical cryogenic processes. Due to the low strength of graphite equipment, excessive brine delivery pressure will cause the graphite block structure to rupture and damage the equipment. At the same time, excessive brine pump outlet pressure will cause damage to the subsequent refrigeration unit heat exchanger tubes.

[0005] 2. If the operating pressure of the brine system is too low, the heat exchanger at a higher position in the device will not be able to circulate brine, causing the temperature of the material at the inlet and outlet of the heat exchanger to seriously deviate from the process indicators, which is very likely to cause safety accidents and production accidents. Utility Model Content

[0006] The utility model aims to provide an industrial refrigerated brine conveying circulation device capable of automatically stabilizing pressure, so as to solve the technical problem that the pressure of the existing brine system is unstable during operation, which leads to damage to relevant components in the system.

[0007] To achieve its purpose, the utility model adopts the following technical solutions:

[0008] An industrial refrigerated brine transportation circulation device capable of automatically stabilizing pressure, comprising a brine circulation tank, a brine pump, a refrigeration unit and a heat exchanger connected in sequence through pipelines, wherein the heat exchanger is a shell-and-tube heat exchanger;

[0009] A first brine reflux pipe is provided on the pipeline between the brine pump and the refrigeration unit, the first brine reflux pipe is connected to the brine circulation tank, and a reflux regulating valve is provided on the first brine reflux pipe;

[0010] The evaporator outlet of the refrigeration unit is connected to the shell-side brine inlet of the heat exchanger through a pipeline, and a pressure transmitter and a flow regulating valve are respectively provided on the pipeline. The shell-side brine outlet of the heat exchanger is connected to the brine circulation tank through a second brine reflux pipe;

[0011] The heat exchanger tube inlet is provided with a material inlet pipe, the tube outlet is provided with a material outlet pipe, and the material outlet pipe is provided with a thermometer;

[0012] The pressure transmitter and the thermometer are electrically connected to the signal input end of the programmable PLC controller, and the signal output end of the programmable PLC controller is electrically connected to the reflux regulating valve and the flow regulating valve.

[0013] As a further improvement of the technical solution of the present invention, the bottom of the brine circulation tank is connected to the brine pump inlet through a pump inlet pipe, and the brine pump outlet is connected to the evaporator pipe inlet of the refrigeration unit through a pump outlet pipe.

[0014] Furthermore, the brine pump is a centrifugal pump.

[0015] Furthermore, a polyurethane coating for cold preservation is provided on the brine pipeline in the brine transportation circulation device.

[0016] By adopting the above technical solution, the beneficial effects of the utility model are as follows:

[0017] In order to avoid the situation in which the rear-end heat exchanger frequently adjusts the opening of the brine valve to ensure the material temperature during the operation of the existing brine system, resulting in fluctuations in the water supply pressure of the brine system and causing damage to related system components or safety accidents, the utility model arranges a brine reflux pipe connected to the brine circulation tank on the pipeline between the brine pump and the refrigeration unit, and arranges a reflux regulating valve on the brine reflux pipe to ensure stable system pressure; at the same time, a pressure transmitter and a flow regulating valve are arranged on the pipeline connecting the refrigeration unit and the shell side of the heat exchanger to facilitate monitoring of the operating pressure of the brine system, and a programmable PLC controller is used to achieve automatic pressure stabilization during the brine delivery process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of the industrial refrigerated brine conveying circulation device capable of automatically stabilizing pressure according to the present invention;

[0019] In the figure: 1-brine circulation tank; 2-brine pump; 3-refrigeration unit; 4-heat exchanger; 5-pump inlet pipe; 6-pump outlet pipe; 7-first brine reflux pipe; 8-reflux regulating valve; 9-pressure transmitter; 10-programmable PLC controller; 11-flow regulating valve; 12-thermometer; 13-material outlet pipe; 14-material inlet pipe; 15, second brine reflux pipe. DETAILED DESCRIPTION

[0020] The structure and working principle of the present utility model are described in detail below with reference to the accompanying drawings.

[0021] Reference Figure 1 The utility model provides an industrial refrigerated brine transportation circulation device with automatic pressure stabilization, comprising a brine circulation tank 1, a brine pump 2, a refrigeration unit 3 and a heat exchanger 4, wherein the heat exchanger 4 is a shell-and-tube heat exchanger; the bottom of the brine circulation tank 1 is connected to the inlet of the brine pump 2 through a pump inlet pipe 5, and the outlet of the brine pump 2 is connected to the evaporator tube side inlet of the refrigeration unit 3 through a pump outlet pipe 6; a first brine reflux pipe 7 is provided on the pump outlet pipe 6, and a reflux regulating valve 8 is provided on the first brine reflux pipe 7; the evaporator outlet of the refrigeration unit 3 is connected to the shell side brine inlet of the heat exchanger 4 through a pipe, and a pressure transmitter 9 and a flow regulating valve 11 are respectively provided on the pipe, and the shell side brine outlet of the heat exchanger 4 is connected to the brine circulation tank 1 through a second brine reflux pipe 15; the tube side inlet of the heat exchanger 4 is provided with a material inlet pipe 14, the tube side outlet is provided with a material outlet pipe 13, and the material outlet pipe 13 is provided with a thermometer 12.

[0022] The pressure transmitter 9 and the thermometer 12 are electrically connected to the signal input end of the programmable PLC controller 10, and the signal output end of the programmable PLC controller 10 is electrically connected to the reflux regulating valve 8 and the flow regulating valve 11. The opening and closing of the reflux regulating valve 8 and the flow regulating valve 11 are controlled by the programmable PLC controller 10. The specific control process is as follows:

[0023] 1. The material outlet temperature index of the heat exchanger 4 is set in the programmable PLC controller 10. The thermometer 12 detects the temperature value in real time and transmits the temperature signal to the programmable PLC controller 10. The programmable PLC controller 10 realizes automatic control of the material outlet temperature by controlling the opening of the flow control valve 11.

[0024] 2. The operating pressure of the device is set in the programmable PLC controller 10. The pressure transmitter 9 detects the device pressure value in real time and transmits the pressure signal to the programmable PLC controller 10. The programmable PLC controller 10 controls the flow control valve 11 to gradually close. When the pressure on the transmitter 9 begins to rise, the reflux control valve 8 automatically opens to ensure the stability of the brine pressure. When the programmable PLC controller 10 controls the flow control valve 11 to gradually open and the pressure on the transmitter 9 slowly decreases, the reflux control valve 8 automatically closes slowly, thus ensuring that the brine pressure is stable at 0.45-0.6 MPa.

[0025] Based on the above, the operation process of the utility model is as follows:

[0026] 1. All pipes and fittings in the device are pressure tested for leaks at a pressure of 1.0 MPa, and high-performance gaskets are used at the pipe flange connections.

[0027] 2. Install the brine pump 2 stably and avoid large vibrations during operation.

[0028] 3. Send the prepared brine with qualified concentration to the brine circulation tank 1 and open the relevant valves on the brine circulation pipeline.

[0029] 4. Turn on the brine pump 2 and the refrigeration unit 3 to establish a circulation of the chilled brine system.

[0030] 5. The programmable PLC controller 10 controls the opening and closing of the flow control valve 11 and the reflux control valve 8 through the signal input of the thermometer 12 and the pressure transmitter 9.

[0031] The above operation method can realize automatic pressure stabilization during the circulation of frozen brine transportation.

Claims

1. An industrial chilled brine transport circulation device capable of automatically stabilizing pressure, comprising a brine circulation tank (1), a brine pump (2), a refrigeration unit (3) and a heat exchanger (4) connected in sequence by pipelines, characterized in that: The heat exchanger (4) is a shell and tube heat exchanger; A first brine reflux pipe (7) is provided on the pipeline between the brine pump (2) and the refrigeration unit (3), the first brine reflux pipe (7) is connected to the brine circulation tank (1), and a reflux regulating valve (8) is provided on the first brine reflux pipe (7); The evaporator outlet of the refrigeration unit (3) is connected to the shell-side brine inlet of the heat exchanger (4) through a pipeline, and a pressure transmitter (9) and a flow regulating valve (11) are respectively provided on the pipeline. The shell-side brine outlet of the heat exchanger (4) is connected to the brine circulation tank (1) through a second brine reflux pipe (15); The heat exchanger (4) is provided with a material inlet pipe (14) at the tube side inlet, a material outlet pipe (13) at the tube side outlet, and a thermometer (12) is provided on the material outlet pipe (13); The pressure transmitter (9) and the thermometer (12) are electrically connected to the signal input end of the programmable PLC controller (10), and the signal output end of the programmable PLC controller (10) is electrically connected to the reflux regulating valve (8) and the flow regulating valve (11).

2. The industrial chilled brine conveying circulation device capable of automatically stabilizing pressure according to claim 1, characterized in that: The bottom of the brine circulation tank (1) is connected to the inlet of the brine pump (2) through a pump inlet pipe (5), and the outlet of the brine pump (2) is connected to the evaporator pipe inlet of the refrigeration unit (3) through a pump outlet pipe (6).

3. The industrial chilled brine transportation circulation device capable of automatically stabilizing pressure according to claim 1, characterized in that: The brine pump (2) is a centrifugal pump.

4. An industrial chilled brine transportation circulation device capable of automatic pressure stabilization according to any one of claims 1 to 3, characterized in that: The brine pipeline in the brine transport circulation device is provided with a polyurethane coating for cold preservation.

Images