Constant-temperature environment titer heating device and test method

Abstract

The invention discloses a constant-temperature environment titration calorimetry device and a test method. The constant-temperature environment titration calorimetry device comprises a constant-temperature temperature control system, a calorimetry system, a titration system and a controller. Wherein the titration system comprises a titration container, a liquid storage container, a third control valve and a fourth control valve, the titration container is communicated with the reaction container, the liquid storage container is communicated with the titration container, the third control valve is arranged between the titration container and the liquid storage container, the fourth control valve is arranged between the titration container and the reaction container, and the liquid storage container is used for storing a sample solution; the titration system is configured as follows: when negative pressure is formed in the titration container, the third control valve is opened, the fourth control valve is closed, and the sample solution in the liquid storage container enters the titration container; when the pressure in the titration container is increased, the third control valve is closed, the fourth control valve is opened, and the sample solution in the titration container is injected into the calorimetric container.

Description

Technical Field

[0001] The invention relates to the field of microcalorimeters, and in particular to a constant temperature environment titration calorimeter and a testing method. Background Art

[0002] Isothermal titration calorimetry (ITC) is an important method for studying biothermodynamics and biokinetics developed in the past three decades. It uses a highly sensitive and highly automated microcalorimeter to continuously and accurately monitor and record the calorimetric curve of a changing process, and simultaneously provides thermodynamic and kinetic information in situ, online and non-destructively. The complete thermodynamic parameters of biomolecular interactions can be obtained through isothermal titration calorimetry, including binding constants, number of binding sites, molar binding enthalpy, molar binding entropy, molar constant-pressure heat capacity and kinetic parameters (such as enzyme activity, enzymatic reaction Michaelis constant and enzyme turnover number), etc. Isothermal titration calorimetry has a wide range of applications and is suitable for physical chemistry, biochemistry, biophysics, chemical biology, life sciences, pharmacology, soil science, colloid chemistry and other disciplines.

[0003] In the related art, the mainstream isothermal titration calorimeters are all thermal conductivity differential calorimeters, whose constant temperature medium is a metal block and air, and a thermopile is used to measure the relationship between the temperature difference and time of the calorimeter. Its structure is complex, the production is difficult, and the cost is high. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a constant temperature environment titration calorimeter, which can improve titration efficiency, reduce costs and maintain measurement accuracy.

[0005] A testing method is also proposed.

[0006] A constant temperature environment titration calorimeter according to an embodiment of the first aspect of the present invention comprises:

[0007] A constant temperature control system, comprising a constant temperature cavity for containing a constant temperature solution and a temperature measuring device for detecting the temperature of the constant temperature solution;

[0008] A calorimetric system, comprising a calorimetric cavity disposed in the constant temperature cavity, a reaction container and a calorimeter both disposed in the calorimetric cavity, wherein the calorimetric cavity is used to be coated with the constant temperature solution, the reaction container is thermally insulatedly connected to the calorimetric cavity and is used to contain the reaction solution, and the calorimeter is used to measure the temperature of the reaction solution;

[0009] A titration system, comprising a titration container connected to the reaction container, a liquid storage container connected to the titration container, a third control valve disposed between the titration container and the liquid storage container, and a fourth control valve disposed between the titration container and the reaction container, wherein the liquid storage container is used to store a sample solution;

[0010] The titration system is configured as follows: when negative pressure is formed in the titration container, the third control valve is opened, the fourth control valve is closed, and the sample solution in the liquid storage container enters the titration container; when the pressure in the titration container increases, the third control valve is closed, the fourth control valve is opened, and the sample solution in the titration container is injected into the calorimetric container.

[0011] The constant temperature environment titration calorimeter according to the first embodiment of the present invention has at least the following beneficial effects:

[0012] 1. The calorimetric cavity is coated with a constant temperature solution, which makes the calorimetric cavity more isolated from the outside temperature and the measurement more accurate;

[0013] 2. When negative pressure is formed in the titration container, the third control valve opens automatically and the fourth control valve closes, and the sample solution in the liquid storage container automatically enters the titration container, making the transportation of the sample solution more convenient. When the pressure in the titration container increases, the third control valve closes and the fourth control valve opens, and the sample solution in the titration container enters the reaction container for reaction. When the pressure in the titration container remains unchanged, the third control valve and the fourth control valve remain closed. By controlling the change in pressure, the sample solution in the liquid storage container is accurately absorbed into the titration container, and the sample solution in the titration container is accurately transported to the reaction container, thereby improving titration efficiency, reducing costs and maintaining measurement accuracy.

[0014] According to some embodiments of the present invention, the heat exchanger comprises a first heat exchange pipe, a first control valve and a second control valve, wherein the first heat exchange pipe is arranged in the reaction container for a heat exchange medium to pass through;

[0015] The controller is configured to: before titrating the sample solution, control the heat exchange medium to flow through the first heat exchange pipe; and when the temperature of the thermometer is consistent with the temperature of the calorimeter, control the first control valve and the second control valve to close the first heat exchange pipe.

[0016] According to some embodiments of the present invention, the heat exchanger further comprises a driving pump disposed in the constant temperature cavity, the driving pump being connected to the constant temperature cavity and the first heat exchange pipe;

[0017] The controller is configured to control the driving pump to drive the constant temperature solution to flow through the first heat exchange pipe.

[0018] According to some embodiments of the present invention, the constant temperature control system includes a heating element disposed within the constant temperature cavity and a cooling pipeline partially disposed within the constant temperature cavity, the heating element is used to heat the constant temperature solution, and the cooling pipeline is used to cool the constant temperature solution.

[0019] According to some embodiments of the present invention, the cooling circuit includes a cooling source, a cold-end heat conductor, a cooling pipe, a refrigeration pipe and a refrigeration medium. The cooling pipe is arranged inside the constant temperature cavity, and the refrigeration pipe is arranged outside the constant temperature cavity and is connected with the cooling pipe to form a closed loop. The refrigeration medium is arranged inside the closed reflux and can circulate along a preset flow direction. The cold-end heat conductor is arranged on the refrigeration pipe and is used to transfer the cooling capacity of the cooling source to the refrigeration medium inside the refrigeration pipe.

[0020] According to some embodiments of the present invention, the constant temperature control system further includes a stirring member disposed within the constant temperature cavity, and the stirring member is used to stir the constant temperature solution.

[0021] According to some embodiments of the present invention, the constant temperature control system further comprises a temperature controller electrically connected to the heating element and the calorimeter;

[0022] The temperature controller is configured to: when the calorimeter detects that the temperature of the constant temperature solution is lower than a preset temperature, obtain a first heating power of the heating element required to heat the constant temperature solution to the preset temperature, and the controller controls the heating element to heat with the first heating power.

[0023] According to some embodiments of the present invention, the constant temperature environmental titration calorimeter further comprises a controller electrically connected to the titration system;

[0024] The titration system further comprises a fifth control valve disposed between the titration container and the liquid storage container, wherein the fifth control valve is electrically connected to the controller;

[0025] The controller is configured to: control the fifth control valve to be opened when the third control valve is opened; and control the fifth control valve to be closed when the third control valve is closed.

[0026] According to some embodiments of the present invention, the titration system also includes a second heat exchange pipe connected to the constant temperature chamber, a portion of the second heat exchange pipe is wrapped around the outside of the liquid storage container or is arranged inside the liquid storage container, and the second heat exchange pipe is used for heat exchange with the sample solution.

[0027] The testing method according to the second aspect of the present invention comprises:

[0028] S1: Control the temperature of the sample solution in the titration system, the temperature of the reaction solution in the calorimetric system and the temperature of the constant temperature solution in the constant temperature control system to be consistent;

[0029] S2: The controller controls the titration system to titrate a preset amount of sample solution into the calorimetric container of the calorimetric system, and the sample solution and the reaction solution generate reaction heat or dilution heat;

[0030] S3: The calorimetric system obtains the reaction heat or dilution heat and the electrical calibration potential curve;

[0031] Repeat S1 to S3 until the titrated sample solution reaches a preset total amount.

[0032] The testing method according to the embodiment of the second aspect of the present invention has at least the following beneficial effects: by maintaining the consistency of the sample solution temperature, the reaction solution temperature and the constant temperature solution temperature, the determination of the sample solution reaction heat is more accurate, and the influence of other heat can be eliminated through electrical calibration, thereby improving the accuracy of the test.

[0033] According to some embodiments of the present invention, in S2, the emptying step of the titration system before titrating the sample solution includes:

[0034] S21: the titration container in the titration system again draws out the sample solution in the liquid storage container under negative pressure;

[0035] S22: the titration system is inverted and the exhaust is upward;

[0036] S23: Repeat S21 to S23 multiple times.

[0037] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0039] Figure 1 A schematic diagram of the structure of a constant temperature environment titration calorimeter according to an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of the structure of a titration system in a constant temperature environment titration calorimeter according to an embodiment of the present invention;

[0041] Figure 3 It is a structural schematic diagram of the third control valve and the fourth control valve of the titration system in the constant temperature environment titration calorimeter according to one embodiment of the present invention;

[0042] Figure 4 It is a schematic diagram of the structure of a calorimetric system in a constant temperature environmental titration calorimetric device according to an embodiment of the present invention;

[0043] Figure 5 A schematic diagram of the structure of a constant temperature control system in a constant temperature environment titration calorimeter according to an embodiment of the present invention;

[0044] Figure 6 A schematic diagram of the structure of a cooling pipeline of a constant temperature control system in a constant temperature environmental titration calorimeter according to an embodiment of the present invention;

[0045] Figure 7 is the relationship between the potential V and temperature T of the sensor in the calorimetric experiment;

[0046] Figure 8 is the relationship between temperature T and time t in the calorimetric experiment;

[0047] Fig. 9 This is the thermoelectric potential curve of the titration between HCl solution and THAM solution.

[0048] Figure Number:

[0049] Constant temperature control system 100; constant temperature cavity 110; temperature measuring device 120; heating element 130; cooling pipeline 140; cooling source 141; cold end heat conducting element 142; cooling pipe 143; cooling pipe 144; stirring element 150; temperature controller 160;

[0050] Calorimetric system 200; calorimetric chamber 210; reaction container 220; calorimeter 230; heat exchanger 240; first heat exchange pipe 241; first control valve 242; second control valve 243; drive pump 244; electric heating element 250;

[0051] titration system 300; titration container 310; liquid storage container 320; third control valve 330; first valve body 331; first spring 332; first movable plug 333; first joint 334; fourth control valve 340; second valve body 341; second spring 342; second movable plug 343; second joint 344; fifth control valve 350; second heat exchange pipe 360;

[0052] Controller 400. DETAILED DESCRIPTION

[0053] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0054] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0055] In the description of the present invention, "a number" refers to one or more than one, and "a plurality" refers to two or more than two. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0056] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0057] Reference Figures 1 to 6As shown, the first embodiment of the present invention proposes a constant temperature environment titration calorimetry device, including: a constant temperature control system 100, a calorimetric system 200, a titration system 300 and a controller 400; the constant temperature control system 100 includes a constant temperature cavity 110 for holding a constant temperature solution and a thermometer 120 for detecting the temperature of the constant temperature solution; the calorimetric system 200 includes a calorimetric cavity 210 arranged in the constant temperature cavity 110, a reaction container 220 and a calorimeter 230 both arranged in the calorimetric cavity 210, and a heat exchanger 240 arranged in the reaction container 220, the calorimetric cavity 210 is used to be coated with the constant temperature solution, the reaction container 220 is thermally insulated and connected to the calorimetric cavity 210, and is used to hold a reaction solution, the calorimeter 230 is used to measure the temperature of the reaction solution, and the heat exchanger 240 is used to adjust the temperature of the reaction solution; the titration system 300 is sealed and thermally insulated and connected to the reaction container to quantitatively titrate the sample solution to the reaction container The titration system 300 includes a titration container 310 connected to the reaction container 220, a liquid storage container 320 connected to the titration container 310, a third control valve 330 disposed between the titration container 310 and the liquid storage container 320, and a fourth control valve 340 disposed between the titration container 310 and the reaction container 220, wherein the liquid storage container 320 is used to store the sample solution; the titration system 300 is configured such that: when a negative pressure is formed in the titration container 310, the third control valve 330 is opened, the fourth control valve 340 is closed, and the sample solution in the liquid storage container 320 enters the titration container 310; the fourth control valve 340 is configured such that: when the pressure in the titration container 310 increases, the third control valve 330 is closed, the fourth control valve 340 is opened, and the sample solution in the titration container 310 is injected into the calorimetric container; the controller 400 is electrically connected to the constant temperature control system 100, the calorimetric system 200 and the titration system 300.

[0058] It is worth understanding that by coating the calorimetric cavity 210 with the constant temperature solution, the calorimetric cavity 210 is better isolated from the external temperature and the measurement is more accurate. When negative pressure is formed in the titration container 310, the third control valve 330 is automatically opened and the fourth control valve 340 is closed, and the sample solution in the liquid storage container 320 automatically enters the titration container 310, and the transportation of the sample solution is more convenient. When the pressure in the titration container 310 increases, the third control valve 330 is closed and the fourth control valve 340 is opened, and the sample solution in the titration container 310 enters the reaction container 220 for reaction. When the pressure in the titration container 310 remains unchanged, the third control valve 330 and the fourth control valve 340 remain closed, and the sample solution in the liquid storage container 320 is accurately absorbed into the titration container 310 by controlling the change in pressure, and the sample solution in the titration container 310 is accurately transported to the reaction container 220, thereby improving titration efficiency, reducing costs and maintaining measurement accuracy.

[0059] In this embodiment, the constant temperature control system 100 includes a constant temperature cavity 110 and a thermometer 120. The constant temperature cavity 110 includes a constant temperature tank and a cover plate covered on the constant temperature tank. The side wall of the constant temperature tank has at least one air insulation layer, and the cover plate is thermally insulated and connected to the constant temperature tank. The thermometer 120 is a temperature control thermistor. The constant temperature control system 100 also includes an agitator and an inlet and outlet drainer. The agitator can quickly mix the constant temperature solution so that the constant temperature solution is evenly distributed. The inlet and outlet drainer can automatically add the constant temperature solution or discharge the constant temperature solution to control the liquid level of the constant temperature solution in the constant temperature tank, wherein the constant temperature solution can be water.

[0060] The calorimetric system 200 includes a calorimetric cavity 210, a reaction vessel 220, a calorimeter 230, and a heat exchanger 240. The calorimetric cavity 210 and the reaction vessel 220 form a Dewar flask and a Dewar flask cover. The reaction vessel 220 is the inner liner of the Dewar flask, and the calorimetric cavity 210 is the outer shell of the Dewar flask. There is a gap between the inner liner and the outer shell, and the gap forms a vacuum for heat insulation. The calorimetric cavity 210 and the reaction vessel 220 can also form other heat-insulating cavities. The Dewar flask is made of corrosion-resistant hard glass with an effective volume of 100 cm -3 or 50cm -3 The Dewar flask cover is made of polytetrafluoroethylene with a low thermal conductivity and is shaped like an "I" to ensure that the Dewar flask is almost completely immersed in the constant temperature water bath and is always at a constant temperature. The inner wall of the Dewar flask cover is embedded with stainless steel high vacuum (vacuum degree reaches 10 -5 Pa) insulation layer to reduce heat exchange. The Dewar flask body uses a high vacuum silver-plated interlayer (vacuum degree reaches 10 -5 Pa), plus a layer of stainless steel protective layer filled with insulation material for double insulation to reduce the loss of heat radiation and heat exchange. Submersible magnetic stirrer replaces traditional mechanical stirring to avoid heat leakage caused by heat conduction of the stirring rod. And the magnetic stirrer is fixedly installed at the bottom of the Dewar flask to prevent the magnetic stirrer from moving. The glass stirrer is driven by a synchronous motor, and the stirring speed is 360r / min (adjustable). The actual operation shows that its stirring speed can quickly make the temperature and concentration of the reaction system reach complete uniformity.

[0061] The calorimeter 230 includes a temperature measuring thermistor, which constitutes one of the four bridge arms of the temperature measuring Weston bridge, and generates a DC voltage signal. The signal change generated by the Weston bridge in the temperature range of about 0.8K is linearly related to the temperature change of the calorimetric solvent. The signal is collected by the computer after linear amplification. The fixed resistor of the temperature measuring Weston bridge, that is, the winding resistor used for electrical calibration and auxiliary heating, is a high-precision resistor wound with manganese copper wire, and its temperature coefficient is very small, so that the resistance value can basically remain unchanged during heating. The winding resistor is installed in a thin-walled glass tube filled with silicone oil with good thermal conductivity to ensure that the electrical energy is quickly transferred to the reaction system in the form of heat. The power supply of the temperature measuring Weston bridge is a precision regulated DC power supply. The precision constant current source is an electric energy calibration power supply, and its current accuracy is very high, which can ensure the precision of the supplied current. The time of electric heating is measured by an electronic timer in a computer, and the timing accuracy is 0.001s. The calorimeter 230 also includes a temperature sensing element, which is a bead-shaped thermistor with a resistance of about 50k at 298.15K. The thermistor itself has a very small heat capacity and reacts quickly to temperature. In order to minimize the thermal hysteresis of the temperature sensing element, the thermistor is installed in a thin-walled glass tube filled with silicone oil with good thermal conductivity. The time constant of the temperature measuring element is measured to be 3s, and the sensitivity of the temperature measuring system can reach 510 -5 K.

[0062] The titration container 310 is similar to a syringe, and includes a straight cylindrical body, a plunger, and a stepper motor, and the stepper motor is connected to the plunger transmission to accurately control the moving distance of the plunger, so that the volume of the reaction solution titrated each time is basically the same. The body has an injection port, wherein the titration container 310 is connected to the liquid storage container 320 through the third control valve 330 and the fifth control valve 350, and the liquid storage container 320 is connected to the reaction container 220 through the fourth control valve 340 and the injection port; the third control valve 330 and the fourth control valve 340 are both spring valves. The liquid storage container 320 can be a container such as a liquid storage bottle or a liquid storage box that can accommodate a sample solution.

[0063] Among them, refer to Figure 3As shown, the third control valve 330 includes a first valve body 331, a first spring 332, a first movable plug 333 and a first joint 334. The first valve body 331 is connected to the titration container 310 and is connected to the liquid storage container 320 through the first joint 334. The first movable plug 333 can move from the first valve body 331 to the first joint 334 and can block the first joint 334. The first spring 332 is arranged on a side of the first movable plug 333 away from the first joint 334, and the first spring 332 is away from the first joint 334. One end of the first movable plug 333 abuts against the first valve body 331. When the pressure in the titration container 310 is normal or increases, the first movable plug 333 blocks the first joint 334 through the first spring 332, so that the third control valve 330 remains closed. When the pressure in the titration container 310 is negative pressure, the first movable plug 333 compresses the first spring 332 under the action of the pressure difference, so that the first movable plug 333 opens the first joint 334, so that the third control valve 330 remains open, and the sample solution in the liquid storage container 320 enters the titration container 310.

[0064] Among them, refer to Figure 3 As shown, the fourth control valve 340 includes a second valve body 341, a second spring 342, a second movable plug 343 and a second joint 344. The second valve body 341 is connected to the titration container 310 and is connected to the reaction container 220 through the second joint 344. The second movable plug 343 can move from the second valve body 341 to the second joint 344 and can block the second valve body 341. The second spring 342 is arranged on a side of the second movable plug 343 away from the second valve body 341, and the second spring 342 is away from the second joint 344. One end of the second valve body 341 abuts against the second valve body 341. When the pressure in the titration container 310 is normal or negative, the second movable plug 343 blocks the second valve body 341 through the second spring 342, so that the fourth control valve 340 remains closed; when the pressure in the titration container 310 increases, the second movable plug 343 compresses the second spring 342 under the action of the pressure difference, so that the second movable plug 343 opens the second joint 344, so that the fourth control valve 340 remains open, and the sample solution in the titration container 310 drips into the reaction container 220. The first valve body 331 and the second valve body 341 can be provided separately, or they can be made together to form a three-way valve.

[0065] Reference Figure 1 and Figure 4 As shown, in some specific embodiments of the present invention, the constant temperature environment titration calorimetry device further includes a controller 400 electrically connected to the calorimetric system 200;

[0066] The calorimetric system 200 also includes a heat exchanger 240 disposed in the reaction container 220, and the heat exchanger 240 is used to adjust the temperature of the reaction solution. The heat exchanger 240 also includes a driving pump 244 disposed in the constant temperature chamber 110, and the driving pump 244 connects the constant temperature chamber 110 and the first heat exchange pipe 241; the controller 400 is configured to: control the driving pump 244 to drive the constant temperature solution to flow through the first heat exchange pipe 241.

[0067] It should be noted that after the development of the constant temperature environment titration calorimeter entered the testing stage, when Tris was used to titrate hydrochloric acid for the calorimeter calibration, after the first titration, the temperature of the system was difficult to cool down naturally. The system reached thermal equilibrium only after about twelve hours of natural cooling. Only then could the second titration be performed. The system took too long to reach thermal equilibrium, and the instrument had no practical value.

[0068] The heat exchanger 240 includes a first heat exchange pipe 241, a first control valve 242 and a second control valve 243. The first heat exchange pipe 241 is arranged in the reaction container 220 for the heat exchange medium to pass through. The controller 400 is configured to: before titrating the sample solution, control the heat exchange medium to flow through the first heat exchange pipe 241; when the temperature of the thermometer 120 is consistent with the temperature of the calorimeter 230, control the first control valve 242 and the second control valve 243 to close the first heat exchange pipe 241. The temperature of the mixed solution of the reaction solution and the sample solution in the reaction container 220 is actively adjusted through the first heat exchange pipe 241, so that the temperature of the mixed solution can be quickly restored to the initial temperature, so as to facilitate the next titration and improve the titration efficiency. Among them, the first heat exchange pipe 241 can be a spiral tube or a U-shaped tube or a tube of other shapes, the temperature of the heat exchange medium can be controlled by a separate system, or the heat exchange medium is a constant temperature solution in the constant temperature chamber 110, and the temperature of the constant temperature solution is adjusted to be consistent with the temperature of the reaction solution by the constant temperature control system 100, the production cost of the equipment is lower, which is conducive to the promotion of the equipment.

[0069] It should be noted that when the temperature of the thermometer 120 is consistent with the temperature of the calorimeter 230, the controller 400 directly controls the first control valve 242 and the second control valve 243 to close, so as to isolate the first heat exchange pipe 241 and the constant temperature chamber 110, so that the first heat exchange pipe 241 is not affected by the constant temperature solution in the constant temperature chamber 110, and further, the reaction container 220 is not affected by the constant temperature solution, and the heat measurement in the reaction container 220 is more accurate.

[0070] It is worth understanding that by coating the calorimetric cavity 210 with a constant temperature solution, the calorimetric cavity 210 is better isolated from the external temperature and the measurement is more accurate; after the titration system 300 titrates once, the sample solution and the reaction solution react in the reaction vessel 220 and change the temperature in the reaction vessel 220. The temperature of the reaction solution is difficult to automatically return to the original temperature, and the next titration takes longer. The heat exchanger 240 quickly adjusts the temperature in the reaction vessel 220 to be consistent with the temperature of the constant temperature solution, so that the titration system 300 can quickly start the next titration, and the titration system 300 has a higher titration efficiency.

[0071] In addition, the calorimetric system 200 further includes an electric heating element 250, which is used for electrical calibration. The electric heating element 250 is a heating resistor.

[0072] In this embodiment, the driving pump 244 is a circulating water pump, and is a submersible circulating water pump. The driving pump 244 can actively transport the constant temperature solution to flow, so that the constant temperature solution can pass through the first heat exchange pipe 241, and the constant temperature solution in the constant temperature chamber 110 is heat exchanged with the reaction solution, so that the temperature of the constant temperature solution and the reaction solution can be quickly adjusted to be consistent, and the constant temperature control system 100 can adjust the temperature of the constant temperature solution, so that the temperature of the constant temperature solution is always maintained at a preset initial temperature, thereby realizing the temperature control of the entire device. Among them, both ends of the first heat exchange pipe 241 are connected to the constant temperature chamber 110 to form a circulation loop, so that the circulating water pump can continuously extract the constant temperature solution from one end of the first heat exchange pipe 241 into the first heat exchange pipe 241, and the constant temperature solution flows out from the other end of the first heat exchange pipe 241 after passing through the first heat exchange pipe 241.

[0073] It is worth understanding that the heat exchanger 240 actively inputs the constant temperature solution into the reaction container 220 by driving the pump 244, so that the temperature of the mixed solution can be quickly restored to the initial temperature, so as to facilitate the next titration and improve the titration efficiency.

[0074] Reference Figure 1 and Figure 5 As shown, in some specific embodiments of the present invention, the constant temperature control system 100 includes a heating element 130 disposed in a constant temperature cavity 110 and a cooling pipeline 140 partially disposed in the constant temperature cavity 110, the heating element 130 is used to heat the constant temperature solution, and the cooling pipeline 140 is used to cool the constant temperature solution.

[0075] It should be noted that the sample solution reacts with the reaction solution, and the reaction can be an endothermic reaction or a heat releasing reaction. The constant temperature control system 100 can adjust the temperature of the constant temperature solution in the constant temperature cavity 110 through the heating element 130 and the cooling line 140, so that the temperature of the constant temperature solution remains constant, thereby making the calorimetric system 200 in the constant temperature solution less affected by the external temperature, and the calorimetric system 200 is more accurate in measuring the heat of reaction. At the same time, after the constant temperature solution in the first heat exchange pipe 241 is mixed with the constant temperature solution in the constant temperature cavity 110, the constant temperature control system 100 can also quickly take away the temperature change brought by the constant temperature solution in the first heat exchange pipe 241, so that the temperature of the constant temperature solution in the constant temperature control system 100 remains constant, and the temperature in the reaction vessel 220 can be quickly restored to the same as the constant temperature solution, thereby improving the titration efficiency.

[0076] In this embodiment, the constant temperature control system 100 also includes a thermistor, which is used as a temperature sensor to sense the temperature. The thermistor constitutes one of the four bridge arms of the Weston bridge, generates a voltage signal and sends it to the precision temperature controller 160. The signal is compared with the millivolt setter in the precision temperature controller 160 to obtain a deviation signal. The deviation signal is amplified and indicated by the deviation table, and sent to the PID regulator for PID operation, and outputs a 0-10mA signal with PID regulation law to the thyristor trigger. The thyristor trigger uses a single-junction tube Chixun oscillator to output a phase-shifted trigger pulse. The heating power of the heating element 130 is driven and controlled by the thyristor actuator. In order to improve the temperature control stability, the heater voltage feedback is introduced to overcome the influence of the grid voltage fluctuation on the heater heating power. In order to prevent the influence of the ambient temperature on the tank temperature when it is too high, a cooling pipeline 140 is added in the constant temperature tank to facilitate the adjustment of the tank temperature. In this embodiment, the heating element 130 is a heating resistor, and the cooling pipeline 140 is actively cooled by a semiconductor refrigeration device.

[0077] Reference Figure 6 As shown, in some specific embodiments of the present invention, the cooling circuit includes a cooling source 141, a cold end heat conductor 142, a cooling pipe 143, a cooling pipe 144 and a cooling medium, the cooling pipe 143 is arranged in the constant temperature cavity 110, the cooling pipe 144 is arranged outside the constant temperature cavity 110, and is connected with the cooling pipe 143 to form a closed loop, the cooling medium is arranged in the closed loop, and can circulate along a preset flow direction, the cold end heat conductor 142 is arranged in the cooling pipe 144, and is used to transfer the cooling capacity of the cooling source 141 to the cooling medium in the cooling pipe 144.

[0078] It is worth understanding that, at the location of the refrigeration pipe 144, the cold end heat conductor 142 transfers the cooling capacity generated by the refrigeration source 141 to the refrigerant medium in the refrigeration pipe 144, the temperature of the refrigerant medium decreases, and flows through the cooling pipe 143 through a closed loop. At the location of the cooling pipe 143, the cooling pipe 143 exchanges heat with the constant temperature solution in the constant temperature cavity 110 to cool the constant temperature solution, and then the refrigerant medium repeatedly passes through the refrigeration pipe 144-cooling pipe 143 to continuously cool the constant temperature solution.

[0079] In this embodiment, the cooling source 141 is a semiconductor refrigerator. The semiconductor refrigerator is a device that uses the thermoelectric effect of semiconductors to generate cooling capacity. If an N-type semiconductor and a P-type semiconductor are connected to each other and a direct current is connected, the temperature at one end will decrease and the temperature at the other end will increase. If the power supply is reversed, the temperature change will occur in the opposite direction. This phenomenon is called the thermoelectric effect. The temperature difference and cooling capacity generated by a pair of semiconductor thermoelectric elements are very small. In actual application, many pairs of thermoelectric elements are connected in parallel and in series, also known as thermoelectric piles. A single-stage thermoelectric pile can obtain a temperature difference of about 60°C, that is, the cold end temperature can reach -10°C to -20°C. Increasing the number of thermoelectric piles can increase the temperature difference.

[0080] In addition, the heating element 130 can also be a separate heating pipeline, and the structure of the heating pipeline is the same as that of the cooling pipeline, except that the cooling pipeline 140 is connected to the cold end of the semiconductor refrigerator through the cold end heat conductor 142, and the heating pipeline is connected to the hot end of the semiconductor refrigerator through the hot end heat conductor, wherein the heating pipeline and the cooling pipeline 140 can share the pipeline located in the constant temperature cavity 110, and this part of the pipeline is both a cooling pipe 143 and a heating pipe, and the heating pipeline and the cooling pipeline are switched by two two-position three-way valves. The cooling medium in the cooling pipeline circulates under the drive of the pump body.

[0081] Reference Figure 1 and Figure 5 As shown, in some specific embodiments of the present invention, the constant temperature control system 100 further includes a stirring member 150 disposed in the constant temperature chamber 110, and the stirring member 150 is used to stir the constant temperature solution.

[0082] It is worth understanding that by actively stirring the constant temperature solution through the stirring element 150, the constant temperature solutions of different temperatures can be quickly mixed when the constant temperature solution is locally heated or locally cooled, thereby improving the temperature uniformity of the constant temperature solution and the accuracy of the temperature detection of the constant temperature solution.

[0083] In this embodiment, the stirring element 150 includes stirring blades and a motor connected to the stirring blades. The stirring blades are arranged in the constant temperature cavity 110. The motor drives the stirring blades to stir, and the start and stop of the motor can be controlled by the controller 400.

[0084] Reference Figure 1 and Figure 5 As shown, in some specific embodiments of the present invention, the constant temperature control system 100 also includes a temperature controller 160 electrically connected to the heating element 130 and the calorimeter 230; the temperature controller 160 is configured to: when the calorimeter 230 detects that the temperature of the constant temperature solution is lower than the preset temperature, obtain the first heating power of the heating element 130 required to heat the constant temperature solution to the preset temperature, and the controller 400 controls the heating element 130 to heat the first heating power.

[0085] In this embodiment, the constant temperature environment titration calorimeter further includes a data processing system, which may be a computer.

[0086] It is worth understanding that when the calorimeter 230 detects that the temperature of the isothermal solution has dropped, the data processing system calculates the first heating power required for the isothermal solution to rise to the original temperature, and then controls the heating element 130 to heat the first heating power so that the isothermal solution can be restored to the original temperature. Among them, when the ambient temperature is lower than the temperature of the isothermal solution, causing the temperature of the isothermal solution to change, the heating element 130 can be continuously heated, and the heating power is the heat exchange power between the isothermal solution and the ambient temperature, so that the isothermal solution can maintain a dynamic thermal balance and maintain its own temperature unchanged.

[0087] Reference Figure 1 , Figure 2 and Figure 3 As shown, in some specific embodiments of the present invention, the constant temperature environment titration calorimeter further includes a controller 400 electrically connected to the titration system 300; the titration system 300 further includes a fifth control valve 350 disposed between the titration container 310 and the liquid storage container 320, and the controller 400 is configured to: when the third control valve 330 is opened, control the fifth control valve 350 to be opened; when the third control valve 330 is closed, control the fifth control valve 350 to be closed.

[0088] In this embodiment, the fifth control valve 350 is a solenoid valve, which is electrically connected to the controller 400 and is controlled by the controller 400 .

[0089] It should be noted that the liquid storage container 320 is inverted, and the third control valve 330 is connected to the bottom of the liquid storage container 320. When there is only the third control valve 330, the third control valve 330 is affected by the gravity of the sample solution in the liquid storage container 320, making it difficult for the third control valve 330 to be completely sealed, resulting in the sample solution in the liquid storage container 320 being easily leaked into the titration container 310, causing the titration amount to increase, affecting the accuracy of the final result. Therefore, in this embodiment, on the basis of the third control valve 330, a fifth control valve 350 is separately provided, and the sealing effect between the liquid storage container 320 and the titration container 310 is further strengthened by the fifth control valve 350, so that the titrated sample solution amount is more accurate and the detection accuracy is improved. Among them, the fifth control valve 350 can be opened together with the third control valve 330, or the fifth control valve 350 is opened before the third control valve 330, and the fifth control valve 350 can be closed together with the third control valve 330, or the fifth control valve 350 is closed after the third control valve 330.

[0090] Reference Figure 1 and Figure 2 As shown, in some specific embodiments of the present invention, the titration system 300 also includes a second heat exchange pipe 360 ​​connected to the constant temperature chamber 110, and a portion of the second heat exchange pipe 360 ​​is wound around the outside of the liquid storage container 320 or is arranged inside the liquid storage container 320, and the second heat exchange pipe 360 ​​is used for heat exchange with the sample solution.

[0091] It is worth understanding that the second heat exchange pipe 360 ​​performs heat exchange with the sample solution through the constant temperature solution, so that the sample solution and the constant temperature solution reach thermal equilibrium, and finally the sample solution, the reaction solution and the constant temperature solution all reach thermal equilibrium, reducing the impact of the temperature difference on the test accuracy and improving the accuracy of the test.

[0092] In this embodiment, the second heat exchange pipe 360 ​​is a pipe bolted around the outer peripheral surface of the liquid storage container 320, and the second heat exchange pipe 360 ​​is also connected to the constant temperature cavity 110 through a circulating water pump, and the circulating water pump can actively transport the constant temperature liquid to flow through the second heat exchange pipe 360 ​​and return to the constant temperature cavity 110. Among them, the circulating water pump is a submersible circulating water pump.

[0093] In some specific embodiments of the present invention, the testing method according to the second aspect of the present invention includes:

[0094] S1: Control the temperature of the sample solution in the titration system 300, the temperature of the reaction solution in the calorimetric system 200 and the temperature of the constant temperature solution in the constant temperature control system 100 to be consistent;

[0095] S2: The controller 400 controls the titration system 300 to titrate a preset amount of the sample solution into the calorimetric container of the calorimetric system 200, and the sample solution and the reaction solution generate reaction heat or dilution heat;

[0096] S3: The calorimetric system 200 obtains the reaction heat or the dilution heat and the electrical calibration potential curve;

[0097] Repeat S1 to S3 until the titrated sample solution reaches the preset total amount.

[0098] It is worth understanding that by maintaining the consistency of the sample solution temperature, the reaction solution temperature and the constant temperature solution temperature, the determination of the sample solution reaction heat is more accurate, and the influence of other heat can be eliminated through electrical calibration, thereby improving the accuracy of the test.

[0099] In some specific embodiments of the present invention, in S2, the evacuation step before the titration system 300 titrates the sample solution includes:

[0100] S21: The titration container 310 in the titration system 300 again draws out the sample solution in the liquid storage container 320 under negative pressure;

[0101] S22: The titration system 300 is inverted and vented upward;

[0102] S23: Repeat S21 to S23 multiple times.

[0103] It is worth understanding that when the titration system 300 is inverted, the air in the titration system 300 will automatically rise, and then the air can be discharged first. When the titration system 300 is inverted multiple times and the air is discharged, the air content in the titration system 300 can be reduced, thereby improving the accuracy of the titration of the titration system 300.

[0104] To facilitate understanding, some specific embodiments are used for illustrative purposes below.

[0105] In this embodiment, the specific calibration process of the titration system 300 is used as an example to illustrate the calibration steps as follows:

[0106] ① Degas the distilled water by vacuum ultrasonication.

[0107] ② Turn on the power of the instrument, preheat the instrument and keep the constant temperature of the constant temperature water bath at (298.15±0.001)K.

[0108] ③ The liquid storage container 320 filled with degassed distilled water is connected to the titration container 310 through the third control valve, the liquid storage container 320 is covered with a serpentine copper tube, and the serpentine copper tube is connected to the circulating water pump in the constant temperature cavity 110. Turn on the circulating water pump switch to pass the degassed distilled water in the constant temperature liquid storage container 320 with 298.15K constant temperature water.

[0109] ④Operate the control panel and set the stepper motor's subdivision, up and down movement steps, up and down movement frequency and other parameters according to the experimental needs to determine the volume of degassed distilled water to be titrated. For example, when the subdivision is adjusted to 64, the up and down movement frequency is 3200, and the up and down movement steps are set to 198000, the titrated volume is 4.99973±0.00068mL.

[0110] ⑤ Click the “up” button on the control panel, negative pressure is formed in the titration container 310 , and the third control valve 330 opens, allowing the dehydrated distilled water in the liquid storage container 320 to enter the titration container 310 .

[0111] ⑥ Invert the titration system 300 and click the "down" button on the control panel. The pressure in the titration container 310 increases, and the fourth control valve 340 opens, so that the gas in the titration container 310 is discharged.

[0112] ⑦ Repeat steps ⑤ and ⑥ to exhaust the gas in the titration container 310 as much as possible and fill it with dehydrated distilled water.

[0113] ⑧ Accurately weigh the clean and dry ground-mouth weighing bottle on a Sartorius CPA225D electronic balance (d=0.01 mg) and remove the tares.

[0114] ⑨ Place the weighing bottle under the injection port of the titration container 310, click the "Auto" button on the control panel, and add distilled water. After the titration is completed, quickly cover the ground cover and weigh accurately.

[0115] The results are listed in Tables 1 and 2. As can be seen from Tables 1 and 2, the standard error of the titration volume is equal to ±6.8×10 -4 mL and ±6.9×10 -4 mL. The results show that the accuracy of the titration device meets the design requirements.

[0116] Table 1 Calibration of titration volume range 5mL (298.15K)

[0117] Serial number Total amount of water / g <![CDATA[Titration volume / cm -3 > 1 5.00019 5.00084 2 4.99926 4.99991 3 4.99866 4.99931 4 4.99902 4.99967 5 4.99890 4.99955 6 4.99794 4.99859 7 4.99877 4.99942 8 5.00015 5.00080 9 4.99871 4.99936 10 4.99919 4.99984 4.99908±0.00068 4.99973±0.00068

[0118] Table 2 Calibration of titration volume range 10mL (298.15K)

[0119] Serial number Total amount of water / g <![CDATA[Titration volume / cm -3 > 1 9.99943 10.00073 2 9.99809 9.99939 3 9.99806 9.99936 4 9.99917 10.00047 5 9.99836 9.99966 6 9.99718 9.99848 7 9.99824 9.99954 8 9.99830 9.99960 9 9.99796 9.99926 10 9.99921 10.00051 9.99840±0.00069 9.99970±0.00069

[0120] Note: The density of water at 298.15K is 0.99987 g·cm -3 .

[0121] In this example, the titration heat of HCl solution and THAM solution was measured.

[0122] The ingredients are as follows:

[0123] THAM: NBS-742a heat of solution standard material, provided by the U.S. Bureau of Standards, prepared to 0.08604 mol·dm -3 of solution.

[0124] HCl: high purity, prepared at 0.09986 mol·dm -3 (This concentration is the calibration value using the standard reagent anhydrous sodium carbonate) solution.

[0125] The experimental operating temperature was 298.15K; HCl solution was used as the titrant; the titration amount for each experiment was 4.99973 cm -3 ; Dewar flask reaction vessel contains 100cm -3 of THAM solution.

[0126] The specific steps are as follows:

[0127] a) Turn on the power of the instrument, preheat the instrument and keep the constant temperature of the water bath at (298.15±0.001)K.

[0128] b) Accurately measure 100cm -3 ±0.08604mol·dm -3 The THAM solution was placed into a 220 Dewar flask as a reaction vessel.

[0129] c) The HCl solution is loaded into the liquid storage container 320 and installed in the titration system 300. The second heat exchange pipe 360 ​​is installed. The circulating water pump switch is turned on and 298.15K constant temperature water is introduced to maintain the constant temperature.

[0130] d) Setting the titration parameters through the panel of the controller 400, and setting the subdivision of the stepper motor, the number of up and down movement steps (ie, the titration volume), the up and down movement frequency and other parameters according to the experimental needs.

[0131] e) The controller 400 controls the fifth control valve 350 to open, and the stepper motor drives the plunger away from the injection port, so that the HCl solution in the liquid storage container 320 enters the titration container 310.

[0132] f) The titration system 300 is turned upside down, the controller 400 controls the fifth control valve 350 to close, and the stepper motor pushes the plunger to move toward the injection port to exhaust.

[0133] g) Repeat steps e) and f) to exhaust all the gas in the titration container 310 and fill it with the sample solution.

[0134] h) Insert the injection needle of the titration system 300 into the reaction vessel 220 and seal the connection position with a rubber stopper.

[0135] i) Open the driving pump 244 connected to the first heat exchange pipe 241 and the first control valve 242 and the second control valve 243 at both ends of the first heat exchange pipe 241, and introduce 298.15K constant temperature water into the first heat exchange pipe 241 to keep the calorimetric system 200 at a constant temperature.

[0136] j) Data processing system for collection.

[0137] k) Observe the change of the potential curve. When the potential curve tends to be stable, close the drive pump 244, the first control valve 242 and the second control valve 243, stop passing the constant temperature solution, and allow the calorimetric system 200 to maintain a constant temperature naturally, and keep the mass of the constant temperature solution in the first heat exchange pipe 241 constant.

[0138] l) The data processing system ends the acquisition and starts the acquisition again. Observe the change of the potential curve and confirm that the baseline is stable before officially starting the baseline acquisition.

[0139] m) After the data processing system collects the baseline for about 8-10 minutes, the controller 400 controls the titration system 300 to perform titration. At this time, the temperature in the calorimetric system 200 rises rapidly. When the temperature reaches the highest point, the temperature will gradually decrease.

[0140] n) Starting from the time when the temperature reaches the highest point, about 8-10 minutes later, the controller 400 controls the calorimetric system 200 to perform electrical calibration.

[0141] o) After the electrical calibration is completed, record the time of the electrical calibration. At this time, the temperature curve will rise to the highest point and then gradually decrease. Start timing from when the temperature reaches the highest point. After about 8-10 minutes, the entire collection work is completed. Save the data, as attached Fig. 9 As shown, notes: 1. The curve numbers in the figure represent the order of titration; 2. The abcd segment is the titration reaction stage, and the cdef segment is the electrical calibration stage.

[0142] p) Repeat steps i) to o) to perform the second, third, ... tenth titration.

[0143] r) After the experiment, wash the syringe, titration needle and reaction vessel 220 Dewar flask three times with distilled water and dry them for later use.

[0144] The electrical calibration process is as follows:

[0145] The titration heat is calculated according to the following formula:

[0146] Δ t H / Δ t T=Δ e Q / Δ e T

[0147] Δ t H is the titration heat; Δ e Q is the electrical correction heat; Δ t TTemperature rise during titration; Δ e T Correction temperature rise during electrical calibration process;

[0148] The electrical correction heat can be calculated by formula (2):

[0149] Δ e Q=I 2 R

[0150] I is the corrected current, R is the corrected heating resistance, and t is the power-on time. In order to obtain accurate electrical correction heating, the temperature change (ΔT), current (I), resistance (R), and power-on time (t) must be corrected and calibrated.

[0151] (a) Relationship between the potential and temperature of a temperature sensor

[0152] Since the experimental measurement is the electric potential, it needs to be converted into temperature first. The relationship between the electric potential and temperature of the sensor measured in the experiment is shown in Table 3. The relationship between the electric potential and temperature of the sensor (p o =101.325kPa)

[0153] Table 3 Relationship between the potential and temperature of the sensor (p o =101.325kPa)

[0154] <![CDATA[T / K a ]]> V / mV 298.650±0.001 <![CDATA[46.98959±5.7×10 -5 ]]> 298.350±0.001 <![CDATA[19.07394±3.6×10 -5 ]]> 298.150±0.001 <![CDATA[0.26136±2.5×10 -5 ]]> 297.950±0.001 <![CDATA[–18.90109±5.5×10 -5 ]]> 297.650±0.001 <![CDATA[–46.94086±5.0×10 -5 ]]>

[0155] According to the data in Table 3, Figure 7 As shown. And perform linear fitting to get its straight line equation, and then take its differential to get the relationship between temperature and potential:

[0156] V=-28046.68423+94.06936×T

[0157] or

[0158]

[0159] (b) Correction relationship for temperature change (ΔT)

[0160] In a calorimetric experiment, the relationship between temperature T and time t is as follows: Figure 8 shown.

[0161] The ab, bc, and cd segments of the curve represent the temperature-time relationship of the initial, main, and final stages, respectively, and T i and T f Represent the temperatures at the beginning and end of the main period, (T f -Ti ) is the observed value of the temperature rise of the calorimeter, which must be corrected for stirring heat and heat leakage to obtain an accurate temperature rise value. Since the stirring heat is constant, it is assumed that the heating rate of the calorimeter is only proportional to the temperature difference between the inside and outside of the jacket of the heat container (i.e., Newton's law of cooling).

[0162]

[0163] Where k is the "cooling constant" of the calorimeter, which can be calculated using formula (6):

[0164]

[0165] Where g ab and g cd Represent the average temperature values ​​at the beginning and end of the period respectively.

[0166] Then, the corrected temperature rise ΔT is calculated based on the formal c value:

[0167] ΔT c. =T f -T i ΔT corr.

[0168] or

[0169] -ΔT c. =T i -T f +ΔT corr

[0170] ② Calibration of current (I): The constant current power supply output was calibrated using a 6-digit GDM-8261A dual-display digital multimeter (accuracy: 0.0035%). During the electric heating period, the current fluctuated by 0.005%, I = 20.3603 mA.

[0171] ③ Resistance (R) calibration: The resistance of the heating resistor was measured and calibrated using a 6-digit GDM-8261A dual-display digital multimeter. During the electric heating period, the resistance fluctuated by 0.02%. At 298.15K, the resistance R = 1274.76Ω.

[0172] ④ Timing calibration: The reading accuracy of the timer of this instrument is 0.001s. The frequency of the timing device is calibrated using international standard time, and the error of the timing frequency is less than 0.001%.

[0173] It should be noted that the titration heat includes the reaction heat of the THAM solution and the HCl solution and the dilution heat of the THAM solution and the HCl solution. Therefore, the dilution heat of the hydrochloric acid must be measured. -3Distilled water and HCl solution were used as sample solutions, and the titration volume for each experiment was 4.99973 cm -3 The experimental operation steps refer to the determination steps of the titration heat of HCl solution against THAM solution. After ten measurements, the dilution heat of HCl solution was measured, and then the reaction heat was calculated by titration heat and dilution heat, and the molar reaction heat was calculated based on the reaction heat.

[0174] Among them, the titration heat results of THAM solution and HCl solution, the dilution heat results of THAM solution and HCl solution, the reaction heat results of THAM solution and HCl solution, and the molar reaction heat results of THAM solution and HCl solution are all recorded in Table 4.

[0175] Table 4 Experimental data of heat of reaction of THAM solution titrated by HCl solution (298.15K)

[0176]

[0177] -Δ t H: titration heat; -Δ d H: heat of dilution; -Δ r H: Reaction heat, -Δ r Hm: molar heat of reaction.

[0178] As shown in Table 4, the molar heat of reaction between hydrochloric acid solution and THAM solution measured in this experiment is (-47.475±0.233) kJ·mol -1 , compared with other determination results (-47.46±0.17) kJ·mol -1 、(-47.49±0.04)kJ·mol -1 、(-47.49±0.25)kJ·mol -1 、(-47.49) kJ·mol -1 、(-47.61) kJ·mol -1 、(-47.40) kJ·mol -1 In comparison, the consistency is within 0.1, thereby proving the reliability of the constant temperature environment titration calorimeter in the present invention.

[0179] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A constant temperature environment titration calorimeter, characterized in that: include: A constant temperature control system, comprising a constant temperature cavity for containing a constant temperature solution and a temperature measuring device for detecting the temperature of the constant temperature solution; A calorimetric system, comprising a calorimetric cavity disposed in the constant temperature cavity, a reaction container and a calorimeter both disposed in the calorimetric cavity, wherein the calorimetric cavity is used to be coated with the constant temperature solution, the reaction container is thermally insulatedly connected to the calorimetric cavity and is used to contain the reaction solution, and the calorimeter is used to measure the temperature of the reaction solution; A titration system, comprising a titration container connected to the reaction container, a liquid storage container connected to the titration container, a third control valve disposed between the titration container and the liquid storage container, and a fourth control valve disposed between the titration container and the reaction container, wherein the liquid storage container is used to store a sample solution; The titration system is configured as follows: when negative pressure is formed in the titration container, the third control valve is opened, the fourth control valve is closed, and the sample solution in the liquid storage container enters the titration container; when the pressure in the titration container increases, the third control valve is closed, the fourth control valve is opened, and the sample solution in the titration container is injected into the calorimetric container.

2. The constant temperature environment titration calorimeter according to claim 1, characterized in that: The constant temperature environmental titration calorimeter also includes a controller electrically connected to the calorimetric system; The calorimetric system further comprises a heat exchanger disposed in the reaction container, the heat exchanger being used to adjust the temperature of the reaction solution, the heat exchanger comprising a first heat exchange pipe, a first control valve and a second control valve, the first heat exchange pipe being disposed in the reaction container for a heat exchange medium to pass through; The controller is configured to: before titrating the sample solution, control the heat exchange medium to flow through the first heat exchange pipe; and when the temperature of the thermometer is consistent with the temperature of the calorimeter, control the first control valve and the second control valve to close the first heat exchange pipe.

3. The constant temperature environment titration calorimeter according to claim 2, characterized in that: The heat exchanger further comprises a driving pump disposed in the constant temperature cavity, wherein the driving pump is connected to the constant temperature cavity and the first heat exchange pipe; The controller is configured to control the driving pump to drive the constant temperature solution to flow through the first heat exchange pipe.

4. The constant temperature environment titration calorimeter according to claim 1, characterized in that: The constant temperature control system includes a heating element arranged in the constant temperature cavity and a cooling pipeline partially arranged in the constant temperature cavity, the heating element is used to heat the constant temperature solution, and the cooling pipeline is used to cool the constant temperature solution.

5. The constant temperature environment titration calorimeter according to claim 4, characterized in that: The cooling circuit includes a cooling source, a cold end heat conductor, a cooling pipe, a refrigeration pipe and a refrigeration medium. The cooling pipe is arranged in the constant temperature cavity, the refrigeration pipe is arranged outside the constant temperature cavity and is connected with the cooling pipe to form a closed loop. The refrigeration medium is arranged in the closed reflux and can circulate along a preset flow direction. The cold end heat conductor is arranged in the refrigeration pipe and is used to transfer the cooling capacity of the cooling source to the refrigeration medium in the refrigeration pipe.

6. The constant temperature environment titration calorimeter according to claim 4, characterized in that: The constant temperature control system further comprises a temperature controller electrically connected to the heating element and the calorimeter; The temperature controller is configured to: when the calorimeter detects that the temperature of the constant temperature solution is lower than a preset temperature, obtain a first heating power of the heating element required to heat the constant temperature solution to the preset temperature, and control the heating element to heat with the first heating power.

7. The constant temperature environment titration calorimeter according to claim 1, characterized in that: The constant temperature environment titration calorimeter also includes a controller electrically connected to the titration system; The titration system further comprises a fifth control valve disposed between the titration container and the liquid storage container, wherein the fifth control valve is electrically connected to the controller; The controller is configured to: control the fifth control valve to be opened when the third control valve is opened; and control the fifth control valve to be closed when the third control valve is closed.

8. The constant temperature environment titration calorimeter according to claim 7, characterized in that: The titration system further comprises a second heat exchange pipe connected to the constant temperature chamber, a portion of the second heat exchange pipe is wound outside the liquid storage container or arranged inside the liquid storage container, and the second heat exchange pipe is used for heat exchange with the sample solution.

9. A testing method, characterized in that: include: S1: Control the temperature of the sample solution in the titration system, the temperature of the reaction solution in the calorimetric system and the temperature of the constant temperature solution in the constant temperature control system to be consistent; S2: The controller controls the titration system to titrate a preset amount of sample solution into the calorimetric container of the calorimetric system, and the sample solution and the reaction solution generate reaction heat or dilution heat; S3: The calorimetric system obtains the reaction heat or dilution heat and the electrical calibration potential curve; S4: Repeat S1 to S3 until the titrated sample solution reaches a preset total amount.

10. The testing method according to claim 9, characterized in that: In S2, the emptying step before the titration system titrates the sample solution comprises: S21: the titration container in the titration system again draws out the sample solution in the liquid storage container under negative pressure; S22: the titration system is inverted and the exhaust is upward; S23: Repeat S21 to S23 multiple times.

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