CN105562133A - Constant temperature device of air bath - Google Patents

Abstract

The invention discloses an air bath constant temperature device, which comprises a box body, the upper layer of which is a constant temperature chamber, and the lower layer is an electric appliance layer; It includes a heating/cooling assembly composed of a semiconductor cooling sheet, a radiator and a fan, which is embedded in the center of the heat insulation layer on the bottom of the constant temperature chamber; the two sides of the semiconductor cooling sheet are respectively attached with a first radiator and a second radiator, The first and second radiators are respectively provided with a first fan and a second fan, the first radiator and the first fan are located in the constant temperature cavity, and the second radiator and the second fan are located outside the constant temperature cavity; the second radiator is also It is connected with the exhaust pipe, and the exhaust pipe leads to the outside of the box, and the second fan is also connected with the diversion pipe, and an air filter is arranged at the bottom of the box body corresponding to the mouth of the diversion pipe. The device has the advantages of simple structure, low cost, convenient use, and higher temperature control accuracy, which can meet the temperature range below room temperature and meet the requirements of higher experimental requirements.

Description

An air bath constant temperature device

technical field

The invention relates to application fields that need to use air as a constant temperature medium to precisely control the ambient temperature, such as constant temperature of instrumentation circuits, physical and chemical performance tests of materials, and performance tests of electronic components, in particular an air bath constant temperature device.

Background technique

Temperature is an important physical parameter and an important factor affecting the system under study. Therefore, when accurately measuring various physical and chemical properties or parameters of the research object, it is necessary to keep the temperature of the measured object constant. A common practice is to place the object under study in a constant temperature bath. The constant temperature bath is a device that provides a constant temperature environment. According to the different constant temperature media, the constant temperature bath can be divided into air bath, water bath, oil bath, molten salt bath, solid thermostat, etc. The most commonly used liquid bath (water bath, oil bath, molten salt bath) constant temperature device has the characteristics of large heat capacity, fast heat transfer and good constant temperature performance. But liquid baths also have disadvantages, such as requiring the test object to be completely sealed, the influence of steam, and so on. The solid thermostat uses a metal block with a large heat capacity as the constant temperature medium. Generally, it is only suitable for constant temperature of small volume objects. If the volume is too large, the heat transfer time is long, and the temperature gradient is too large, the constant temperature performance is poor. The air bath constant temperature bath is suitable for occasions where the precision of the constant temperature is not particularly high and the volume is relatively large. However, common air bath constant temperature devices, such as thermostats, have poor temperature control effects, and the temperature stability can only reach ±1°C, and they can only work in a temperature range higher than room temperature.

Contents of the invention

The purpose of the present invention is to provide a semiconductor cooling chip as a heating device for the poor temperature control effect of the existing air bath constant temperature box, which can only work in the temperature range higher than room temperature and cannot meet the higher experimental requirements. / Refrigeration device, an air bath constant temperature device with air circulation as a temperature uniformity measure, and the temperature stability reaches ±0.01°C.

The object of the present invention is to adopt following technical scheme to realize:

An air bath constant temperature device, including a box body, a power supply, a temperature controller, a temperature sensor connected to the temperature controller, and a heating/cooling assembly connected to the power supply. The difference from the prior art is that the box body is divided into two layers, The upper layer is a constant temperature chamber, the lower layer is an electrical layer, and the power supply and temperature controller are located on the lower layer of the box body; the inner wall of the upper layer constant temperature chamber is provided with a heat insulation layer, and the constant temperature chamber is also equipped with a baffle tube and a temperature sensor; the heating The /cooling assembly is composed of a semiconductor cooling sheet, a radiator and a fan. The heating/cooling assembly is embedded in the center of the heat insulation layer on the bottom of the constant temperature chamber; the two sides of the semiconductor cooling sheet are respectively attached with a first radiator and a second radiator. The first and second radiators are respectively provided with a first fan and a second fan, the first radiator and the first fan are located in the constant temperature cavity, and the second radiator and the second fan are located outside the constant temperature cavity; the second radiator is also It is connected with the exhaust pipe, and the exhaust pipe leads to the outside of the cabinet. The second fan is also connected with the diversion pipe, and the bottom of the cabinet corresponding to the diversion pipe is provided with an air filter.

The heat insulation layer is made of 1-10cm thick material with low thermal conductivity, and the heat insulation layer will be partially wrapped by the constant temperature object to reduce the influence of the external environment temperature fluctuation on the temperature of the constant temperature cavity.

The semiconductor refrigerating sheet is a prior art, which is composed of several pairs of PN joint thermocouples connected in series, and utilizes the Peltier effect to realize heating and cooling.

Pillars are arranged symmetrically and equidistantly on the heat insulation layer on the bottom surface of the constant temperature cavity, and partitions are arranged on the pillars, on which objects to be kept at the constant temperature are placed.

The baffle is made of a thin plate, and the distance between each surface of the baffle and the heat insulation layer is set for air circulation; the bottom plate of the baffle is suspended below the partition and is fixedly connected with the pillar, and the bottom plate of the baffle is connected with the support. The space between the partitions is set for air circulation; the center of the bottom plate of the baffle is provided with a through hole for the ventilation of the first fan.

The temperature sensor is a thermocouple or a thermistor, which is arranged in the air circulation channel in the constant temperature chamber to measure the temperature of the air in real time.

The temperature controller is a controller with PID temperature control function.

The power supply is a switching power supply module capable of converting AC mains power into DC power, and supplies power for semiconductor refrigeration chips, fans and temperature controllers.

The upper opening of the box body is provided with a box cover, and the inner wall of the box cover is arranged on the heat insulation layer.

The bottom of the box body is provided with rollers, the box body is movable, and the use is more convenient. The box body is made of metal sheet, which constitutes the frame of the device, which plays the role of protecting the internal heat insulation layer and supporting and fixing.

The temperature sensor, temperature controller, and heating/cooling assembly constitute a temperature control loop.

The first fan inside the constant temperature chamber blows air to flow, and the air flows along the gap between the outer wall of the baffle tube and the heat insulation layer, the gap between the inner wall of the baffle tube and the object to be heated, and then passes through the first fan, The first radiator and the temperature sensor circulate continuously.

The second radiator outside the constant temperature chamber, the second fan, the guide pipe, and the exhaust pipe form a heat dissipation path. The second fan inhales air through the air guide pipe, flows through the second heat sink, and discharges the air from the casing through the air discharge pipe.

The invention adopts air as a constant temperature medium, uses a semiconductor refrigeration chip as a heating/refrigerating device, and utilizes the circulating flow of air as a means of uniform temperature, which can realize constant temperature in a wide temperature range, and the constant temperature stability reaches ±0.01°C. Compared with common air bath incubators, the present invention has simple structure, compact structure, low cost, convenient use, higher temperature control accuracy, can meet the temperature range lower than room temperature, and meet the requirements of higher experimental requirements.

Description of drawings

Fig. 1 is the structural representation of embodiment;

Fig. 2 is a schematic diagram of the electrical connection of the embodiment.

In the figure, 1. Box cover 2. Box body 2-1. Constant temperature chamber 2-2. Electrical layer 3. Heat insulation layer 4. Baffle tube 5. Object to be heated 6-1. First fan 6-2. Two fans 7. Temperature sensor 8-1. First radiator 8-2. Second radiator 9. Semiconductor cooling chip 10. Exhaust pipe 11. Temperature controller 12. Roller 13. Guide pipe 14. Air filter 15. Power supply 16. Partition plate 17. Pillar.

detailed description

The content of the present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited thereto.

Example

Referring to Figures 1-2, an air bath constant temperature device includes a box body 2, a power supply 15, a temperature controller 7, a temperature sensor 11 connected to the temperature controller 7, and a heating/cooling assembly connected to the power supply 15, the box body 2 Divided into two layers, the upper layer is the constant temperature chamber 2-1, the lower layer is the electrical layer 2-2, the power supply 15 and the temperature controller 7 are located in the lower layer 2-2 of the box body; the inner wall of the constant temperature chamber 2-1 is provided with a heat insulation layer 3 , the constant temperature chamber 2-1 is also provided with a baffle tube 4 and a temperature sensor 7; the heating/cooling assembly is composed of a semiconductor cooling plate 9, a radiator and a fan, and the heating/cooling assembly is embedded in the constant temperature chamber 2-1 The center of the bottom heat insulation layer 3; the two sides of the semiconductor refrigeration sheet 9 are respectively bonded with the first radiator 8-1 and the second radiator 8-2, the first radiator 8-1, the second radiator 8- 2 is provided with a first fan 6-1 and a second fan 6-2 respectively, the first radiator 8-1 and the first fan 6-1 are located in the constant temperature cavity 2-1, the second radiator 8-2 and the second radiator The second fan 6-2 is located outside the constant temperature cavity 2-1; the second radiator 8-2 is connected with the exhaust pipe 10, and the exhaust pipe 10 is connected to the outside of the casing 2, and the second fan 6-2 is connected with the flow guide pipe 13. The bottom of the box body 2 corresponding to the opening of the guide pipe 13 is provided with an air filter 14 .

The heat insulation layer 3 is made of 1-10cm thick low thermal conductivity material, and the heat insulation layer 3 will be partially wrapped by the constant temperature object 5, so as to reduce the influence of the temperature fluctuation of the external environment on the temperature of the constant temperature chamber 2-1.

The semiconductor refrigerating sheet 9 is prior art, and it is formed by series connection of thermocouples formed by some pairs of PN joints, and utilizes the Peltier effect to realize heating and cooling.

The thermal insulation layer 3 on the bottom surface of the constant temperature cavity 2-1 is symmetrically and equidistantly provided with pillars 17, and the pillars 17 are provided with partitions 16, on which the constant temperature objects 5 are placed.

The baffle tube 4 is made of a thin plate, and each surface of the baffle tube 4 is set at a distance from the heat insulation layer 3 for air circulation; The bottom plate of the tube 4 is spaced from the partition 16 for air circulation; the center of the bottom plate of the baffle tube 4 is provided with a through hole for the first fan 6-1 to ventilate.

The temperature sensor 7 is a thermocouple or a thermistor, placed in the passage of air circulation in the constant temperature chamber 2-1, and measures the temperature of the air in real time.

The temperature controller 11 is a controller with a PID temperature control function.

The power supply 15 is a switching power supply module that can convert the AC mains power into a DC power supply, and supplies power to the semiconductor refrigeration sheet 9, the fan, and the temperature controller 11.

The upper opening of the box body 2 is provided with a box cover 1 , and the inner wall of the box cover 1 is arranged on a heat insulating layer 3 .

The bottom of the casing 2 is provided with rollers 12 . The box body 2 is made of thin metal plate, which constitutes the frame of the device and plays the role of protecting the inner heat insulation layer 3 and supporting the fixing device.

The temperature sensor 7, the temperature controller 11, and the heating/cooling assembly form a temperature control feedback loop.

Referring to Fig. 2, the temperature sensor 7 is connected with the temperature controller 11, the temperature controller 11 is connected with the power supply 15, and the semiconductor cooling chip 9, the first fan 6-1, and the second fan 6-2 are respectively connected with the power supply 15,.

The working process of this device is as follows:

The heat insulation layer of the device provides a thermal barrier for the constant temperature chamber, reducing the interference of ambient temperature fluctuations on the internal temperature. The constant temperature chamber uses air as the constant temperature medium, which plays the role of heat transfer. The first fan strengthens the convection of the air, so that the internal temperature can reach uniformity faster. The temperature sensor measures the temperature of the internal flowing air, converts it into an electrical signal, and sends it to the temperature controller. After calculation, the temperature controller outputs a heating or cooling command. The effect of pumping heat, the heat is quickly transferred to the flowing air through the first radiator and the first fan, so that the temperature of the constant temperature chamber increases or decreases, and the continuous cycle control makes the temperature of the constant temperature chamber fluctuate around the set temperature value , to achieve the purpose of constant temperature. The heat absorbed or released by the semiconductor refrigeration sheet towards the outside of the constant temperature chamber is exchanged with the ambient air through the second radiator and the second fan. The air flow enters through the air filter and flows through the guide tube, the second fan, The second radiator is discharged through the exhaust pipe.

The control temperature range of the device in this example is 0°C to 90°C, and when the temperature is stable, the temperature fluctuation in the constant temperature chamber can be controlled to be less than ±0.01°C.

Claims (8)

1. an air bath thermostat, the heating/cooling package comprising casing, power supply, temperature controller, the temperature sensor be connected with temperature controller and be connected with power supply, is characterized in that:

Casing is divided into two layers, and upper strata is constant temperature chamber, and lower floor is electrical equipment layer, and power supply and temperature controller are located at the lower floor of casing;

The inwall in constant temperature chamber, upper strata is provided with thermal insulation layer, is also provided with baffling cylinder and temperature sensor in constant temperature chamber;

Described heating/cooling package is made up of semiconductor chilling plate, radiator and fan, and heating/cooling package is embedded the central authorities at bottom surface, constant temperature chamber thermal insulation layer;

The two sides of semiconductor chilling plate is fitted with the first radiator and the second radiator respectively, first, second radiator is respectively equipped with the first fan and the second fan, first radiator and the first fan are positioned at constant temperature chamber, and the second radiator and the second fan are positioned at outside constant temperature chamber; Second radiator is also connected with exhaust duct, and exhaust duct leads to outside casing, and the second fan is also connected with mozzle, and the bottom half that the water conservancy diversion mouth of pipe is corresponding is provided with airstrainer.

2. air bath thermostat according to claim 1, is characterized in that: on the thermal insulation layer of described constant temperature cavity bottom surface, symmetry is equidistantly provided with pillar, and pillar is provided with dividing plate, is placed on dividing plate by constant temperature object.

3. air bath thermostat according to claim 1, is characterized in that: each face and the thermal insulation layer spacing of described baffling cylinder are arranged, and the base plate of baffling cylinder is unsettled to be located at below dividing plate and to be fixedly connected with pillar, and the base plate of baffling cylinder and clapboard spacing are arranged; The center of baffling tube end plate is provided with the through hole for the first ventilation fan.

4. air bath thermostat according to claim 1, is characterized in that: described temperature sensor is thermocouple or thermistor, and it is arranged in the passage of constant temperature chamber air circulation, measures the temperature of air in real time.

5. air bath thermostat according to claim 1, is characterized in that: described temperature controller is the controller with PID temp. control function.

6. air bath thermostat according to claim 1, is characterized in that: described power supply is for can be converted to galvanic switch power module by electric main.

7. air bath thermostat according to claim 1, it is characterized in that: the suitable for reading of described casing is provided with case lid, the inwall of case lid is located at thermal insulation layer.

8. air bath thermostat according to claim 1, is characterized in that: the bottom of described casing is provided with roller.