A cooling fluid heating system for a settling tank cryogenic cooling unit

Abstract

This application relates to a coolant heating system for a cryogenic cooling unit in a settling tank, belonging to the technical field of industrial cooling equipment. The system includes a heating heat exchange device connected in parallel with the coolant circulation pipeline in the cooling unit. The heating heat exchange device has a steam inlet and an outlet. The steam inlet is connected to the plant's main steam pipeline via a steam pipe, and the steam outlet is connected to a recycling system, a condensate drainage system, or a next-stage heat exchange device via a condensate pipeline. The steam pipeline is equipped with a pressure control device and a flow control device, and the coolant circulation pipeline is equipped with a temperature detection device and a flow detection device. The system also includes a controller, using a programmable logic controller (PLC) as the core of the temperature control system. Parameters such as temperature and flow rate are displayed on a touchscreen, and parameter settings and operational control are performed. This invention solves the technical problem of reduced equipment efficiency caused by excessively low coolant temperature in cryogenic cooling units in low-temperature environments, achieving precise control of coolant temperature and improving system operating efficiency.

Description

Technical Field

[0001] This utility model relates to the field of cooling systems, specifically to a cooling liquid heating system for a settling tank cryogenic cooling unit. Background Technology

[0002] Cryogenic cooling units for settling tanks are commonly used in industrial production for cooling and settling materials during separation processes. In practical applications, controlling the coolant temperature is crucial for ensuring normal equipment operation and production efficiency. Currently, most cooling units employ a single cooling cycle system, lacking an effective temperature regulation mechanism. This is particularly problematic in low-temperature environments or under conditions of insufficient output, where the coolant temperature can easily drop below 18°C, triggering the cryogenic protection mechanism and causing the system to automatically shut down, severely impacting production efficiency. Existing temperature control systems mostly use a single cooling cycle, lacking an effective heating compensation mechanism, and cannot meet the requirements for stable operation under all weather conditions and operating conditions. Furthermore, existing heating systems often have complex structures, low energy efficiency, and insufficient control precision, making it difficult to achieve precise coolant temperature regulation and effectively solve the problem of stable operation of cooling units in low-temperature environments.

[0003] Therefore, there is an urgent need for a heating system that can maintain a stable coolant temperature in low-temperature environments, which can prevent the system from shutting down due to excessively low coolant temperature and achieve precise temperature control to ensure the continuous and stable operation of the settling tank cryogenic cooling unit.

[0004] The information disclosed in the background section above is only intended to enhance the understanding of the technology described herein. Therefore, the background section may contain information that does not constitute prior art known to those skilled in the art in this country. Utility Model Content

[0005] To address the technical problem that cooling units are prone to low-temperature alarms in low-temperature environments and when production is insufficient, and that the system will automatically shut down because the coolant temperature cannot be lower than 18°C, which seriously affects production efficiency, this utility model provides a coolant heating system for a settling tank low-temperature cooling unit to ensure that the coolant temperature is stable within a suitable range, guarantee production continuity, and improve production efficiency.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a cooling liquid heating system for a settling tank low-temperature cooling unit, including a heating heat exchange device connected in parallel with the cooling liquid circulation pipeline in the cooling unit. The heating heat exchange device is provided with a steam inlet and a steam outlet. The steam inlet is connected to the main steam pipeline of the plant through a steam pipeline, and the steam outlet is connected to a recycling system, a condensate discharge system, or a next-stage heat exchange device through a condensate pipeline. The steam pipeline is provided with a pressure control device and a flow control device, and the cooling liquid circulation pipeline is provided with a temperature detection device and a flow detection device.

[0007] Preferably, the pressure control device includes a shut-off valve, a steam pressure reducing valve, a steam pressure regulator, and a pressure gauge, which are sequentially arranged on the steam pipeline.

[0008] Preferably, a steam filter is also provided on the rear side of the pressure gauge.

[0009] Preferably, the flow control device includes a flow regulating valve disposed on the back side of a steam filter on the steam pipeline.

[0010] Preferably, the heating and heat exchange equipment is a plate heat exchanger, which is installed on the coolant circulation pipeline of the cooling unit and connected in parallel.

[0011] Preferably, the coolant circulation pipeline is equipped with temperature sensors and flow sensors before and after the heating heat exchange equipment, which are used to monitor the inlet and outlet temperatures and flow rates of the coolant, respectively.

[0012] Preferably, it also includes a controller, which is installed in a control cabinet and electrically connected to all electronic components in the system.

[0013] The beneficial effects of this utility model are as follows:

[0014] 1. By installing plate heat exchangers in parallel in the coolant circulation system of the cooling unit, the existing steam resources of the plant are used to heat the coolant, which effectively solves the problem of low temperature alarms that easily occur in the cooling unit under low temperature conditions;

[0015] 2. A PLC control system is used to achieve precise temperature control, ensuring that the coolant temperature is stably maintained within a suitable range of not less than 18℃, thus avoiding automatic system shutdown due to low temperature alarms;

[0016] 3. The system is designed with comprehensive pressure control and flow control devices, including shut-off valves, pressure reducing valves, pressure stabilizers, filters, etc., to ensure the stability and safety of steam supply;

[0017] 4. Through real-time monitoring by temperature and flow sensors, combined with intelligent adjustment by the PLC controller, the heating system is automated, requiring no manual intervention and improving system reliability.

[0018] 5. Compared with the prior art, this utility model makes full use of the existing steam resources in the factory, has a simple and practical design, is easy to install, has low maintenance costs, and can significantly improve the continuity and production efficiency of the settling tank production process. Attached Figure Description

[0019] This utility model will be described by way of example and with reference to the accompanying drawings, wherein:

[0020] Figure 1 This is a schematic diagram of the system structure of this utility model. Detailed Implementation

[0021] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0022] Example 1

[0023] A cooling liquid heating system for a settling tank cryogenic cooling unit includes a heating heat exchange device 2 connected in parallel with the cooling liquid circulation pipeline 1 in the cooling unit. The heating heat exchange device 2 is provided with a steam inlet and a steam outlet. The steam inlet is connected to the plant's main steam pipeline 4 through a steam pipeline 3, and the steam outlet is connected to a recycling system, a condensate discharge system, or a next-stage heat exchange device through a condensate pipeline 5. The steam pipeline 3 is equipped with a pressure control device and a flow control device, and the cooling liquid circulation pipeline 1 is equipped with a temperature detection device and a flow detection device.

[0024] The pressure control device includes a shut-off valve 6, a steam pressure reducing valve 7, a steam pressure regulator 8, and a pressure gauge 9, which are sequentially installed on the steam pipeline 3. A steam filter 10 is also installed downstream of the pressure gauge 9. The flow control device includes a flow regulating valve 11 installed downstream of the steam filter 10 on the steam pipeline 3.

[0025] The heating and heat exchange equipment 2 is a plate heat exchanger, which is installed on the coolant circulation pipeline of the cooling unit and connected in parallel. Temperature sensors 12 and flow sensors 13 are installed on both the pipelines before and after the heating and heat exchange equipment 2 to monitor the inlet and outlet temperatures and flow rates of the coolant, respectively.

[0026] The system also includes a controller, which is installed in a control cabinet and electrically connected to all electronic components in the system. A programmable logic controller (PLC) is selected as the core of the temperature control system, as PLCs offer advantages such as high reliability, flexible programming, and powerful functionality. The PLC is installed inside the control cabinet, which is positioned for easy operation and maintenance. A touchscreen is installed on the control cabinet to display parameters such as temperature and flow rate, as well as to perform parameter settings and operational control.

[0027] Specifically, the working principle of the coolant heating system of the settling tank cryogenic cooling unit is as follows:

[0028] When the cooling unit operates in a low-temperature environment, the coolant temperature may drop below the set minimum safe temperature, at which point the coolant needs to be heated. This system connects the heating heat exchanger 2 in parallel with the coolant circulation pipeline 1. When heating is required, some of the coolant will flow through the heating heat exchanger 2 for heating.

[0029] Heating and heat exchange equipment 2 adopts a plate heat exchanger, which has the advantages of high heat exchange efficiency, small size, and light weight. The plate heat exchanger is composed of multiple layers of metal plates, forming alternating flow channels. One side is the coolant flow channel, and the other side is the steam flow channel. Steam enters the plate heat exchanger through the steam inlet, exchanges heat with the coolant, and then condenses into water and is discharged from the steam outlet.

[0030] The pressure control device on steam pipeline 3 ensures that the steam pressure entering the heat exchanger is stable and controllable. First, steam is introduced from the plant's main steam pipeline 4 and controlled by the shut-off valve 6. The steam pressure reducing valve 7 reduces the high-pressure steam to the required operating pressure of the system, typically controlled within the range of 0.2-0.5 MPa. The steam pressure stabilizer 8 further stabilizes the steam pressure, reducing pressure fluctuations and ensuring stable heat exchange performance. The pressure gauge 9 displays the current steam pressure in real time for easy monitoring by operators.

[0031] The steam filter 10, located downstream of pressure gauge 9, filters impurities and water droplets from the steam, preventing them from entering the heat exchanger and causing blockages or damage. The steam filter 10 uses a stainless steel mesh structure with a filtration precision of 100 mesh, effectively removing solid particles and water droplets from the steam.

[0032] The flow regulating valve 11 in the flow control device is installed downstream of the steam filter 10 to precisely control the steam flow rate entering the heat exchanger, thereby controlling the heat exchange capacity. The flow regulating valve 11 is an electrically operated regulating valve, which can automatically adjust its opening degree according to the control signal to achieve precise flow control.

[0033] The temperature detection device on the coolant circulation pipeline includes temperature sensors 12 installed at the inlet and outlet of the heating heat exchanger 2. These are PT100 platinum resistance temperature sensors with a temperature range of -50℃ to 150℃ and an accuracy of ±0.1℃. The flow detection device uses an electromagnetic flow meter with a measurement range of 0-100m³. 3 / h, with an accuracy of ±0.5%.

[0034] The control system uses a Siemens S7-1200 series PLC as the control core and is equipped with a 7-inch color touch screen as the human-machine interface. The PLC collects data from the temperature sensor 12 and the flow sensor 13, and automatically adjusts the opening of the flow regulating valve 11 according to the preset control logic to achieve precise control of the coolant temperature.

[0035] The control system has multiple operating modes: automatic mode, manual mode, and emergency mode. In automatic mode, the system automatically adjusts the heating amount according to preset temperature parameters; in manual mode, the operator can manually set the opening degree of the flow regulating valve 11 via the touch screen; in emergency mode, the system automatically shuts off the steam supply to ensure safety.

[0036] The touchscreen interface is intuitive and user-friendly, displaying key parameters such as system operating status, coolant inlet and outlet temperatures, flow rate, and steam pressure on the main screen. Operators can set temperature control parameters via the touchscreen, such as target temperature, upper and lower temperature limits, and alarm thresholds. The system also features data logging capabilities, recording historical data of operating parameters for later analysis and optimization.

[0037] During system installation, the plate heat exchanger is connected to the coolant circulation pipeline 1 via flanges for easy installation and maintenance. The steam pipeline 3 is made of stainless steel with an insulation layer thickness of at least 30mm to minimize heat loss. The control cabinet is installed no more than 10 meters away from the heat exchange equipment for easy operation and maintenance.

[0038] In practical applications, when the ambient temperature drops and the coolant temperature falls below the set value (typically 18°C), the control system automatically activates the heating function. First, the system checks the data from each sensor to ensure they are normal. Then, it gradually opens the flow regulating valve 11 to control the flow of steam into the heat exchanger. As the coolant temperature rises, the system adjusts the opening of the flow regulating valve 11 based on the real-time temperature. When the temperature reaches the set upper limit (typically 50°C), the system reduces or shuts off the steam supply to maintain the coolant temperature within a suitable range.

[0039] The system also features multiple safety protection functions: over-temperature protection, over-pressure protection, and abnormal flow protection. When any parameter exceeds the safe range, the system will automatically shut off the steam supply and issue an alarm signal to ensure safe operation of the equipment.

[0040] Example 2

[0041] A cooling liquid heating system for a settling tank cryogenic cooling unit includes a heating heat exchange device 2 connected in parallel with the cooling liquid circulation pipeline 1 in the cooling unit. The heating heat exchange device 2 is provided with a steam inlet and a steam outlet. The steam inlet is connected to the plant's main steam pipeline 4 through a steam pipeline 3, and the steam outlet is connected to a recycling system, a condensate discharge system, or a next-stage heat exchange device through a condensate pipeline 5. The steam pipeline 3 is equipped with a pressure control device and a flow control device, and the cooling liquid circulation pipeline 1 is equipped with a temperature detection device and a flow detection device.

[0042] In this embodiment, the pressure control device includes a shut-off valve 6, a steam pressure reducing valve 7, a steam pressure regulator 8, and a pressure gauge 9, which are sequentially arranged on the steam pipeline 3. A steam filter 10 is also provided downstream of the pressure gauge 9. The flow control device includes a flow regulating valve 11 located downstream of the steam filter 10 on the steam pipeline 3.

[0043] Unlike Embodiment 1, the heating and heat exchange device 2 in this embodiment uses a shell-and-tube heat exchanger. The shell-and-tube heat exchanger is installed on the coolant circulation pipeline of the cooling unit, also using a parallel connection method. The shell-and-tube heat exchanger consists of an outer shell and an internal heat exchange tube bundle. Coolant flows inside the tubes, and steam flows on the shell side, exchanging heat through the tube walls. Shell-and-tube heat exchangers are characterized by their robust structure, high pressure resistance, and adaptability to high-temperature and high-pressure operating conditions.

[0044] Temperature sensors 12 and flow sensors 13 are installed on both the pipes before and after the heat exchanger 2 in the coolant circulation pipeline to monitor the inlet and outlet temperatures and flow rates of the coolant, respectively. Temperature sensor 12 is a thermocouple type with a temperature range of -100℃ to 200℃ and an accuracy of ±0.5℃. Flow sensor 13 is a turbine flow meter with a measurement range of 0-150m³. 3 / h, with an accuracy of ±1.0%.

[0045] The system also includes a controller, which is installed in a control cabinet and electrically connected to all electronic components in the system. A programmable logic controller (PLC) is selected as the core of the temperature control system. In this embodiment, a Mitsubishi FX3U series PLC is used, equipped with a 10-inch color touchscreen as the human-machine interface. The control cabinet is installed in a location that facilitates operation and maintenance. A touchscreen is installed on the control cabinet to display parameters such as temperature and flow rate, as well as to perform parameter settings and operational control.

[0046] The heat exchange area of ​​the shell-and-tube heat exchanger is 5m². 2The design pressure is 1.0 MPa, and the design temperature is 180℃. The heat exchanger shell is made of carbon steel, and the internal tube bundle is made of 304 stainless steel with a diameter of 20 mm, a wall thickness of 2 mm, and a quantity of 50 tubes. The heat exchanger has removable end caps at both ends for easy cleaning and maintenance.

[0047] Steam pipe 3 is made of carbon steel with a diameter of DN50 and a design pressure of 1.6MPa. Steam pressure reducing valve 7 has a pressure reduction range of 0.1-0.8MPa and can be adjusted according to actual needs. Steam pressure stabilizer 8 has a pressure stabilization accuracy of ±0.02MPa, ensuring stable steam pressure.

[0048] The flow regulating valve 11 is a pneumatic regulating valve equipped with an electric positioner, with a control accuracy of ±2% and a response time of less than 5 seconds, which can achieve fast and accurate flow regulation.

[0049] In addition to basic temperature control functions, the control system also includes energy consumption optimization capabilities. Based on coolant temperature trends and historical data, the system predicts temperature changes and adjusts steam flow in advance to avoid temperature fluctuations and reduce energy consumption.

[0050] In addition to displaying basic operating parameters, the touchscreen interface also features trend graphs, showing the changing trends of parameters such as temperature and flow rate, facilitating operator analysis of system operation. The system also has remote monitoring capabilities, enabling remote monitoring and parameter setting via the factory network.

[0051] In practical applications, when the ambient temperature drops and the coolant temperature falls below the set value (typically 18°C), the control system automatically activates the heating function. The system uses a PID control algorithm to precisely control the opening of the flow regulating valve 11 based on the temperature deviation, achieving accurate control of the coolant temperature. When the temperature reaches the set upper limit (typically 50°C), the system will reduce or shut off the steam supply.

[0052] The system also includes a condensate recovery function. The condensate after the steam condenses in the heat exchanger is collected in the condensate recovery tank through the condensate pipe 5, and then sent back to the boiler room by the condensate pump, realizing the recovery and utilization of energy and improving the overall energy efficiency of the system.

[0053] It should be noted that both Embodiment 1 and Embodiment 2 are types of cooling liquid heating systems for cryogenic cooling units in settling tanks.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A settling tank cryogenic chiller unit coolant heating system characterized by, The device includes a heating heat exchanger (2) connected in parallel with the coolant circulation pipe (1) in the cooling unit. The heating heat exchanger (2) is provided with a steam inlet and a steam outlet. The steam inlet is connected to the main steam pipe (4) of the plant through a steam pipe (3), and the steam outlet is connected to the recycling system, the condensate discharge system, or the next-level heat exchanger through a condensate pipe (5). The steam pipe (3) is provided with a pressure control device and a flow control device, and the coolant circulation pipe (1) is provided with a temperature detection device and a flow detection device.

2. A cooling liquid heating system for a low-temperature cooling unit of a settling tank according to claim 1, characterized in that The pressure control device includes a shut-off valve (6), a steam pressure reducing valve (7), a steam pressure regulator (8), and a pressure gauge (9) sequentially installed on the steam pipeline (3).

3. A cooling liquid heating system for a low-temperature cooling unit of a settling tank according to claim 2, characterized in that A steam filter (10) is also provided on the rear side of the pressure gauge (9).

4. A cooling liquid heating system for a low-temperature cooling unit of a settling tank according to claim 3, characterized in that The flow control device includes a flow regulating valve (11) located on the back side of the steam filter (10) on the steam pipe (3).

5. A cooling liquid heating system for a settling tank cryogenic chiller unit according to claim 1, wherein, The heating and heat exchange equipment (2) is a plate heat exchanger, which is installed on the coolant circulation pipeline of the cooling unit and is connected in parallel.

6. A cooling liquid heating system for a settling tank cryogenic chiller unit according to claim 1, wherein, Temperature sensors (12) and flow sensors (13) are installed in both the pipelines before and after the heating and heat exchange equipment (2) of the coolant circulation pipeline (1).

7. A cooling liquid heating system for a settling tank cryogenic chiller unit according to claim 1, wherein, It also includes a controller, which is installed in a control cabinet and electrically connected to all the electronic components in the system.

Images