An automatic liquid changing thermostat tank

Abstract

The utility model relates to the field of temperature measurement test, concretely is a kind of constant-temperature tank for temperature measurement test can automatically change liquid. Including constant-temperature tank body, liquid level sensor, liquid temperature sensor, heating device, refrigerating plant, multiple liquid storage tank, liquid transmission pipeline and main control unit;Liquid level sensor and liquid temperature sensor are set to constant-temperature tank body inside, for the liquid level and temperature of the liquid in constant-temperature tank acquisition, the temperature conduction component of heating device and refrigerating plant also is located constant-temperature tank body inside, for control liquid temperature in constant-temperature tank;Multiple liquid storage tank includes multiple independent liquid storage tank, each liquid storage tank is connected with constant-temperature tank body by liquid transmission pipeline, and valve and solenoid valve for controlling liquid flow direction are equipped on liquid transmission pipeline.The utility model integrates temperature, liquid level sensor and automatic liquid changing mechanism, so that a single constant-temperature tank can adapt to different temperature zone requirements, reduce manual intervention, improve test efficiency and temperature field stability.

Description

Technical Field

[0001] This utility model relates to the field of temperature measurement and testing, specifically a constant temperature bath with automatic liquid replacement for temperature measurement and testing. Background Technology

[0002] Thermostatic baths are crucial equipment for providing a stable temperature field and are widely used in the calibration and testing of temperature sensors in laboratories. However, due to the limitations of the liquid medium in the temperature field, when testing or controlling different temperature ranges, it is often impossible to achieve stable control of the entire temperature field under the same medium. In practice, to meet the needs of different temperature ranges, metrology personnel have to take some cumbersome measures. One common method is to manually change the liquid medium midway; another method is to expand to multiple temperature baths to generate different temperature fields as needed. However, this method not only increases the number of equipment required, but also increases energy consumption due to the operation of multiple temperature baths, and the switching between different temperature fields also requires manual operation.

[0003] With the increasing demand for metrology and testing services, the need for fully automated metrology services is also becoming increasingly prominent. However, the limitation of a single temperature field liquid medium in a constant temperature bath cannot adapt to the entire temperature testing range, hindering the realization of fully automated temperature metrology processes based on a single constant temperature bath. While expanding to multiple temperature baths for temperature metrology testing avoids manual liquid changes, the complexity of control, high hardware costs, and space requirements for achieving full automation based on multiple baths significantly limit the progress of laboratory deployment in fully automated temperature metrology control. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model discloses an automatic liquid-changing thermostatic bath that integrates temperature and liquid level sensors and an automatic liquid-changing mechanism, enabling a single thermostatic bath to adapt to different temperature zones, reduce manual intervention, and improve testing efficiency and temperature field stability.

[0005] To solve the aforementioned technical problem, the present invention adopts the following technical solution: an automatic liquid-changing thermostatic bath, comprising a thermostatic bath body, a liquid level sensor, a liquid temperature sensor, a heating device, a cooling device, multiple liquid storage tanks, a liquid transmission pipeline, and a main control unit; the liquid level sensor and the liquid temperature sensor are located inside the thermostatic bath body to collect the liquid level and temperature of the liquid in the thermostatic bath; the temperature conduction components of the heating device and the cooling device are also located inside the thermostatic bath body to control the liquid temperature in the thermostatic bath; the multiple liquid storage tanks include multiple independent liquid storage tanks, each of which is connected to the thermostatic bath body through a liquid transmission pipeline; the liquid transmission pipeline is equipped with valves and solenoid valves for controlling the liquid flow direction; the liquid level sensor, the liquid temperature sensor, the heating device, the cooling device, the solenoid valve, and the water pump are connected to the main control unit for control.

[0006] Furthermore, the heating device includes a heating plate and a heat dissipation plate. The heat dissipation plate is the temperature conduction component of the heating device. The heating plate is in contact with the bottom of the constant temperature bath, and the heat dissipation plate is in contact with the heating plate.

[0007] Furthermore, the refrigeration device includes a compressor, a condenser, and a spiral copper tube. The compressor and condenser are located outside the constant temperature bath body. The spiral copper tube is the temperature conduction component of the refrigeration device, which runs through the inside of the constant temperature bath body. The compressor outlet is connected to the condenser inlet through a high-pressure pipe. The condenser outlet is connected to the spiral copper tube inlet. The spiral copper tube outlet is connected to the compressor suction port.

[0008] Furthermore, an expansion valve is installed between the condenser and the inlet of the spiral copper tube.

[0009] Furthermore, each storage tank is connected to the thermostatic bath body by two liquid transfer pipelines: a replenishment pipeline and a drain pipeline. The inlet of the water pump on the replenishment pipeline is connected to the outlet of the storage tank via a solenoid valve, and the outlet of the water pump on the replenishment pipeline is connected to the inlet of the thermostatic bath via a solenoid valve. The inlet of the water pump on the drain pipeline is connected to the outlet of the thermostatic bath via a solenoid valve, and the outlet of the water pump on the drain pipeline is connected to the inlet of the storage tank via a solenoid valve.

[0010] Furthermore, each liquid storage tank is connected to the thermostatic bath body by a liquid transfer pipeline. The liquid transfer pipeline is equipped with one water pump and four solenoid valves. Solenoid valve SV1 is connected between the liquid outlet of the liquid storage tank and the water pump inlet, solenoid valve SV2 is connected between the liquid outlet of the thermostatic bath and the water pump inlet, solenoid valve SV3 is connected between the water pump outlet and the liquid inlet of the liquid storage tank, and solenoid valve SV4 is connected between the water pump outlet and the thermostatic bath inlet.

[0011] Furthermore, a check valve is installed at the pump outlet.

[0012] Furthermore, an overflow pipe is provided between the top of the constant temperature bath and each liquid storage tank.

[0013] Furthermore, the liquid level sensor and liquid temperature sensor are integrated into a single liquid level and liquid temperature sensor, with the probe of the liquid level and liquid temperature sensor extending deep into the liquid in the constant temperature bath.

[0014] Furthermore, the constant temperature bath is also equipped with a stirrer and a drying device.

[0015] The beneficial effects of this invention are as follows: This invention includes a liquid level sensor, a liquid temperature sensor, multiple liquid storage tanks, a liquid transfer pipeline, and a main control unit. The multiple liquid storage tanks store various different liquid media. The main control unit triggers multiple automatic operations such as liquid replenishment, automatic liquid replacement, and overflow based on the liquid level and temperature detected by the liquid level and temperature sensors. It also includes heating and cooling devices to control the temperature of the liquid in the constant temperature bath, ensuring that the temperature remains stable within the set range and that temperature fluctuations are controlled within the set values. A drying device is also included to prevent liquid residue from interfering with the experimental results. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the constant temperature bath; Figure 2 This is a front view of the constant temperature bath; Figure 3 This is a top view of the constant temperature bath; Figure 4 This is a right-side view of the constant temperature bath; Figure 5 This is a schematic diagram of the constant temperature bath from the left. In the diagram: 100, Thermostatic bath assembly; 200, Dual liquid storage tank assembly; 300, Temperature control assembly; 400, Intelligent control assembly; 101, Double spiral copper tube; 102, Liquid level and temperature sensor; 103, Stirrer; 104, Thermostatic bath body; 105, Motor assembly; 201, Liquid storage tank; 202, Micro water pump; 203, Solenoid valve; 204, Overflow pipe; 301, Heating device; 302, Refrigeration device; 302a, Refrigeration compressor; 302b, Condenser; 302c, Expansion valve; 401, Main control module; 402, Touch screen. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1 This embodiment discloses a constant temperature bath with automatic liquid replacement, such as... Figures 1 to 5As shown, the system includes a thermostatic bath assembly 100, a dual-storage tank assembly 200, a temperature control assembly 300, and an intelligent control assembly 400. The thermostatic bath assembly 100 includes a thermostatic bath body 104, a double-helix copper tube 101, a liquid level and temperature sensor 102, a stirrer 103, and a motor assembly 105 disposed within the thermostatic bath body 104. The dual-storage tank assembly 200 includes two storage tanks 201, a liquid transfer pipe connecting the storage tanks 201 and the thermostatic bath body 104, a miniature water pump 202 and a solenoid valve 203 located on the liquid transfer pipe, and an overflow pipe 204 between the storage tanks 201 and the thermostatic bath body 104. The temperature control assembly 300 includes a heating device 301 and a cooling device 302. The intelligent control assembly includes a main control module 401 and a touch screen 402.

[0019] The liquid level sensor and liquid temperature sensor are located inside the thermostatic bath body 104 to collect the liquid level and temperature of the liquid in the thermostatic bath. The temperature conduction components of the heating device 301 and the cooling device 302 are also located inside the thermostatic bath body 104 to control the liquid temperature in the thermostatic bath. The two liquid storage tanks of the dual liquid storage tank assembly 200 are used to store different liquid media and are connected to the thermostatic bath body 104 through a liquid transmission pipeline. The liquid transmission pipeline is equipped with a valve and a solenoid valve 203 for controlling the liquid flow direction. The liquid level sensor, liquid temperature sensor, heating device 301, cooling device 302, solenoid valve 203 and water pump 202 are connected to the main control unit for control.

[0020] The thermostatic bath body 104 is made of high-strength, corrosion-resistant stainless steel, with a cylindrical structure, a diameter of 200mm, and a height of 300mm. It uses double-layer stainless steel, with an inner layer of 5L capacity and corrosion resistance, and an outer layer of 304 for insulation. The middle layer is filled with polyurethane foam material with a thermal conductivity ≤0.03 W / m·K, reducing heat loss. The heating device 301 includes a heating plate and a heat dissipation plate. The heat dissipation plate is the temperature conduction component of the heating device 301. In this embodiment, the heating plate is a ceramic heating plate, which is used for heating the heat dissipation plate. The heat dissipation plate is in contact with the bottom of the thermostatic bath. The purpose of the heat dissipation plate is to ensure that the bottom of the thermostatic bath is heated evenly. The ceramic heating plate requires a separate power supply. The main control unit controls the connection and disconnection of the power supply line between the main control unit and the power supply terminal of the ceramic heating plate through a relay.

[0021] The refrigeration unit 302 includes a compressor 302a, a condenser 302b, an expansion valve 302c, and a spiral copper tube 101. The compressor 302a and condenser 302b are located outside the thermostatic bath body 104. The spiral copper tube 101 is the temperature conduction component of the refrigeration unit 302, penetrating inside the thermostatic bath body 104. The outlet of the compressor 302a is connected to the inlet of the condenser 302b through a high-pressure pipe. The high-pressure pipe is made of double-layer stainless steel, with an inner corrosion-resistant layer and an outer polyurethane foam insulation layer, with a pressure resistance ≥3MPa. The outlet of the condenser 302b is connected to the inlet of the spiral copper tube 101 through the expansion valve 302c. The expansion valve 302c is a safety valve to prevent overpressure. The outlet of the spiral copper tube 101 is connected to the suction port of the compressor 302a through a low-pressure hose. In this embodiment, the spiral copper tube 101 is a double-spiral copper tube, which is embedded in the inner wall of the tank in a double-spiral structure with a pitch of 30mm. It is used for refrigerant circulation and dissipating cold energy to the outside, thereby reducing the temperature inside the constant temperature tank. The two ends of the double-spiral copper tube 101 are respectively connected to the fluid inlet and outlet of the cooling system, and are sealed and fixed by a sealing joint.

[0022] In this embodiment, the liquid level sensor and liquid temperature sensor are integrated into a single liquid level and liquid temperature sensor 102. Specifically, the QDY30A-VD-YR submersible liquid level and liquid temperature sensor manufactured by Vidias can be used. The probe of the liquid level and liquid temperature sensor 102 is inserted into the liquid in the constant temperature bath to detect the liquid level and liquid temperature in the bath in real time, and transmits the measured data to the main control module 401 through a signal line.

[0023] In this embodiment, the thermostatic bath body 104 is also equipped with a stirrer 103 and a drying device. The stirrer 103 includes three three-dimensional curved blades made of corrosion-resistant polytetrafluoroethylene, located in the center of the cylindrical bath. A centrifugal motor assembly 105 is installed at the bottom of the stirrer 103, with an adjustable speed range of 200-2000 rpm. In conjunction with an external drive motor, it forces liquid circulation and eliminates temperature stratification. The stirrer 103 is connected to the motor assembly 105 via a direct-drive structure, and the motor assembly 105 is installed outside the bath. The drying device is used during liquid change. First, the thermostatic bath needs to be emptied of the original liquid medium. After emptying, the bath is dried using an air circulation system before introducing a new liquid medium. The drying device prevents the mixing of different liquids from affecting temperature control stability.

[0024] In this embodiment, the liquid flow direction is controlled by valves and solenoid valve 203, that is, the liquid flows from the storage tank 201 to the constant temperature bath (liquid replenishment), or from the constant temperature bath to the storage tank 201 (liquid drainage). There are two ways to achieve this.

[0025] Method 1: Two liquid transfer pipelines are installed between each liquid storage tank and the thermostatic bath body 104: a replenishment pipeline and a drain pipeline. On the replenishment pipeline, the inlet of water pump 202 is connected to the outlet of the liquid storage tank 201 via solenoid valve SV1, and the outlet of water pump 202 is connected to the inlet of the thermostatic bath via solenoid valve SV2. On the drain pipeline, the inlet of water pump 202 is connected to the outlet of the thermostatic bath via solenoid valve SV3, and the outlet of water pump 202 is connected to the inlet of the liquid storage tank via solenoid valve SV4. This method uses two independent water pumps 202, each responsible for delivery in one direction. This method is relatively reliable and the control logic is relatively simple. When liquid replenishment is needed, turn on the water pump and solenoid valves SV1 and SV2 on the replenishment pipeline, and turn off the water pump and solenoid valves SV3 and SV4 on the drain pipeline. This will allow the liquid to flow from the storage tank to the constant temperature bath. When draining is needed, turn off the water pump and solenoid valves SV1 and SV2 on the replenishment pipeline, and turn on the water pump and solenoid valves SV3 and SV4 on the drain pipeline. This will allow the liquid to flow from the constant temperature bath to the storage tank.

[0026] Method Two: A liquid transfer pipeline is installed between each liquid storage tank 201 and the thermostatic bath body 104. This pipeline includes one water pump 202 and four solenoid valves 203. Solenoid valve SV1 is connected between the outlet of the liquid storage tank 201 and the inlet of the water pump 202; solenoid valve SV2 is connected between the outlet of the thermostatic bath and the inlet of the water pump 202; solenoid valve SV3 is connected between the outlet of the water pump 202 and the inlet of the liquid storage tank; and solenoid valve SV4 is connected between the outlet of the water pump 202 and the inlet of the thermostatic bath. This method uses only one water pump 202, along with four valves, to change the fluid path, thereby achieving bidirectional flow. The core idea is to "reverse the direction of the pipeline." The specific process is as follows: When liquid replenishment is needed, solenoid valves SV1 and SV3 are opened, solenoid valves SV2 and SV4 are closed, and water pump 202 is started. The liquid can only flow along the path "storage tank → solenoid valve SV1 → water pump → solenoid valve SV3 → thermostatic bath," thus achieving liquid flow from the storage tank to the thermostatic bath. When drainage is needed, solenoid valves SV2 and SV4 are opened, solenoid valves SV1 and SV3 are closed, and water pump 202 is started. The liquid can only flow along the path "thermostatic bath → solenoid valve SV2 → water pump → solenoid valve SV4 → storage tank," thus achieving liquid flow from the thermostatic bath to the storage tank. When switching the flow direction, water pump 202 must be stopped first, then the valve status is switched, and water pump 202 is restarted only after confirming that everything is correct. Switching valves while water pump 202 is running is strictly prohibited, otherwise water pump 202 will be damaged. This method has low equipment cost (only one pump is needed), a clear pipeline structure, and simple maintenance, but the operation is slightly cumbersome. You can choose either method one or method two depending on the actual situation.

[0027] To protect water pump 202, a check valve is installed at the outlet of water pump 202 to prevent liquid backflow from impacting water pump 202. Water pump 202 is a miniature diaphragm pump with a flow rate of 0.5L / min and a temperature resistance of -20~80℃. It is linked to solenoid valve 203 through a hose to achieve precise liquid replenishment and drainage.

[0028] In this embodiment, an overflow pipe 204 is provided between the top of the thermostatic bath and each storage tank 201. One end of the overflow pipe 204 is fixed to the overflow port on the top of the thermostatic bath body 104, and the other end flows back to the storage tank. The overflow pipe 204 works in conjunction with the liquid level sensor. When the liquid level in the thermostatic bath exceeds the set upper limit L... max When the overflow pipe 204 automatically guides the excess liquid back to the storage tank to prevent liquid from overflowing.

[0029] The main control unit uses an STM32F103 series microcontroller or a conventional microcontroller with equivalent functions, and integrates a 12-bit ADC module. It is configured to receive liquid level and temperature signals and generate control commands to control the action mechanism to perform actions. For example, when the measured temperature is lower than the set temperature threshold, the heating device 301 is turned on to heat the liquid in the constant temperature bath; when the measured temperature is higher than the set temperature threshold, the cooling device is turned on to cool the liquid in the constant temperature bath; when the liquid level in the constant temperature bath is detected to be lower than the set liquid level, a replenishment command is generated, and the water pump 202 and solenoid valve 203 on the replenishment pipeline are turned on to allow the liquid to flow from the storage tank to the constant temperature bath, thus replenishing the liquid; when the set temperature threshold is detected to have changed, the liquid replacement process is triggered. First, a drain command is generated, and the water pump 202 and solenoid valve 203 on the drain pipeline are turned on to allow the liquid to flow from the constant temperature bath to the storage tank. After determining that the liquid has been drained based on the feedback value of the liquid level sensor, the water pump 202 and solenoid valve 203 on the drain pipeline are turned off, and then the drying device is turned on to perform the drying operation. After the drying operation is completed, the replenishment pipeline of the target storage tank is turned on again to allow the target liquid to flow from the storage tank to the constant temperature bath, thus realizing the liquid replacement process. Although the above process involves software processing of the main control unit, the software processing consists of some basic operations, such as data acquisition, threshold comparison, and generation of control commands to control the opening and closing of corresponding devices. These are conventional technical means in this field, and the innovation of this utility model does not lie in these aspects, nor are they within the scope of protection of this utility model.

[0030] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A constant temperature bath with automatic liquid changing, characterized in that: The system includes a constant temperature bath body, a liquid level sensor, a liquid temperature sensor, a heating device, a cooling device, multiple liquid storage tanks, liquid transfer pipelines, and a main control unit. The liquid level sensor and liquid temperature sensor are located inside the constant temperature bath body to collect the liquid level and temperature within the bath. The temperature conduction components of the heating and cooling devices are also located inside the constant temperature bath body to control the liquid temperature. The multiple liquid storage tanks consist of several independent tanks, each connected to the constant temperature bath body via a liquid transfer pipeline. The liquid transfer pipeline is equipped with valves and solenoid valves to control the liquid flow direction. The liquid level sensor, liquid temperature sensor, heating device, cooling device, solenoid valves, and water pump are connected to the main control unit for control.

2. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: The heating device includes a heating plate and a heat dissipation plate. The heat dissipation plate is the temperature conduction component of the heating device. The heating plate is in contact with the bottom of the constant temperature bath, and the heat dissipation plate is in contact with the heating plate.

3. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: The refrigeration unit includes a compressor, a condenser, and a spiral copper tube. The compressor and condenser are located outside the constant temperature bath body. The spiral copper tube is the temperature conduction component of the refrigeration unit, which runs through the inside of the constant temperature bath body. The compressor outlet is connected to the condenser inlet through a high-pressure pipe. The condenser outlet is connected to the spiral copper tube inlet. The spiral copper tube outlet is connected to the compressor suction port.

4. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: An expansion valve is installed between the condenser and the inlet of the spiral copper tube.

5. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: Two liquid transfer pipelines are provided between each liquid storage tank and the thermostatic bath body: a replenishment pipeline and a drain pipeline. The inlet of the water pump on the replenishment pipeline is connected to the outlet of the liquid storage tank through a solenoid valve, and the outlet of the water pump on the replenishment pipeline is connected to the inlet of the thermostatic bath through a solenoid valve. The inlet of the water pump on the drain pipeline is connected to the outlet of the thermostatic bath through a solenoid valve, and the outlet of the water pump on the drain pipeline is connected to the inlet of the liquid storage tank through a solenoid valve.

6. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: Each storage tank is connected to the thermostatic bath via a liquid transfer pipeline. The liquid transfer pipeline is equipped with one water pump and four solenoid valves. Solenoid valve SV1 is connected between the outlet of the storage tank and the inlet of the water pump, solenoid valve SV2 is connected between the outlet of the thermostatic bath and the inlet of the water pump, solenoid valve SV3 is connected between the outlet of the water pump and the inlet of the storage tank, and solenoid valve SV4 is connected between the outlet of the water pump and the inlet of the thermostatic bath.

7. The constant temperature bath with automatic liquid changing according to claim 5 or 6, characterized in that: A check valve is installed at the water pump outlet.

8. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: An overflow pipe is installed between the top of the constant temperature bath and each liquid storage tank.

9. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: The liquid level sensor and liquid temperature sensor are integrated into one unit, with the probe of the liquid level and liquid temperature sensor inserted into the liquid in the constant temperature bath.

10. The constant temperature bath with automatic liquid changing according to claim 1, characterized in that: The constant temperature bath is also equipped with a stirrer and a drying device.

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