CN219872216U - Microfluidic device for synchronously heating and controlling multiple reagents - Google Patents

Abstract

The utility model provides a multi-reagent synchronous heating control microfluidic device which comprises a plurality of digestion bottles, a plurality of metal sleeves, a plurality of heating wires, a plurality of heating blocks and a plurality of temperature sensors, wherein the digestion bottles are used for placing chemical reagents, the metal sleeves are arranged side by side and used for placing the digestion bottles to heat the digestion bottles, the heating wires are arranged at the bottoms of the metal sleeves and used for heating the metal sleeves, the heating blocks are connected with the heating wires and the temperature sensors through signals and used for controlling the temperature of the heating wires, and the temperature sensors are arranged inside the metal sleeves and used for detecting the temperature in the metal sleeves in real time and feeding back to the heating blocks, so that one set of device is used for simultaneously carrying out heating control on a plurality of chemical reagents.

Description

Microfluidic device for synchronously heating and controlling multiple reagents

Technical Field

The utility model relates to the field of chemical instruments, in particular to a microfluidic device for synchronously heating and controlling multiple reagents.

Background

The heating of chemical reagents is an indispensable step in chemical experiments, and conventional means are usually carried out on only one reagent, such as ammonia nitrogen, COD, total phosphorus, total nitrogen and the like, but the mixing temperature and the heating temperature of each chemical reagent are different.

When the heating device is used, one reagent is often heated at the same time, and after one reagent is heated, other reagents are heated, so that the cost is higher, the time consumption is more, the heating is not convenient enough, and the problems of uneven heating and longer heating time exist.

Disclosure of Invention

In view of this, the utility model provides a microfluidic device for synchronously heating and controlling multiple reagents, which is used for solving the problem that the existing heating device can not heat multiple different reagents at the same time.

The technical scheme of the utility model is realized as follows: a multi-reagent synchronized heating controlled microfluidic device, the device comprising:

a plurality of digestion bottles, a plurality of metal sleeves and a plurality of heating wires;

the digestion bottle is used for placing chemical reagents;

the metal sleeves are arranged side by side and used for placing the digestion bottle so as to heat the digestion bottle;

the heating wire is arranged at the bottom of the metal sleeve and is used for heating the metal sleeve.

On the basis of the above technical solution, preferably, the apparatus further includes a plurality of heating blocks and a plurality of temperature sensors;

the heating block is in signal connection with the heating wire and the temperature sensor and is used for controlling the temperature of the heating wire;

the temperature sensor is arranged inside the metal sleeve and used for detecting the temperature inside the metal sleeve in real time and feeding back the temperature to the heating block.

On the basis of the technical scheme, preferably, 4 digestion bottles are respectively filled with ammonia nitrogen, COD, total phosphorus and total nitrogen; the number of the metal sleeves is 4;

the number of the heating blocks is 4, and an ammonia nitrogen heating circuit, a COD heating circuit, a total phosphorus heating circuit and a total nitrogen heating circuit are respectively arranged in the 4 heating blocks;

the output end of the heating circuit is electrically connected with the heating wire, and the working current of the heating wire is controlled, so that the temperature of the heating wire is controlled; the number of the heating wires is 4;

the number of the temperature sensors is 4, and an ammonia nitrogen temperature measuring circuit, a COD temperature measuring circuit, a total phosphorus temperature measuring circuit and a total nitrogen temperature measuring circuit are respectively arranged in the 4 temperature sensors.

Preferably, the ammonia nitrogen heating circuit comprises the following specific circuits;

triode Q1, MOS tube M1 and resistance R1, R2, R3;

the base electrode of the triode Q1 is electrically connected with one ends of a current limiting resistor R1 and a resistor R2, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R2, the collector electrode is electrically connected with the grid electrode of the MOS tube M1 and one end of a resistor R3, the other end of the resistor R3 is electrically connected with a power supply 12V1, the drain electrode of the MOS tube M1 is electrically connected with the power supply 12V1, and the source electrode outputs a voltage VCC12V1 to a heating wire.

The total phosphorus heating circuit comprises the following specific circuits;

triode Q2, MOS tube M2 and resistance R4, R5, R6;

the base electrode of the triode Q2 is electrically connected with one ends of a current limiting resistor R4 and a resistor R5, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R5, the collector electrode is electrically connected with the grid electrode of the MOS tube M2 and one end of a resistor R6, the other end of the resistor R6 is electrically connected with a power supply 12V2, the drain electrode of the MOS tube M2 is electrically connected with the power supply 12V2, and the source electrode outputs a voltage VCC12V2 to a heating wire.

Preferably, the COD heating circuit comprises a specific circuit;

triode Q3, MOS tube M3 and resistance R7, R8, R9;

the base electrode of the triode Q3 is electrically connected with one ends of a current limiting resistor R7 and a resistor R8, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R8, the collector electrode is electrically connected with the grid electrode of the MOS tube M3 and one end of a resistor R9, the other end of the resistor R9 is electrically connected with a power supply 12V3, the drain electrode of the MOS tube M3 is electrically connected with the power supply 12V3, and the source electrode outputs a voltage VCC12V3 to a heating wire.

Preferably, the total nitrogen heating circuit comprises the following specific circuits;

triode Q4, MOS tube M4 and resistance R10, R11, R12;

the base electrode of the triode Q4 is electrically connected with one ends of a current limiting resistor R10 and a resistor R11, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R11, the collector electrode is electrically connected with the grid electrode of the MOS tube M4 and one end of a resistor R12, the other end of the resistor R12 is electrically connected with a power supply 12V4, the drain electrode of the MOS tube M4 is electrically connected with the power supply 12V4, and the source electrode outputs a voltage VCC12V4 to a heating wire.

Preferably, the ammonia nitrogen temperature measuring circuit comprises the following specific circuits;

operational amplifier U21A, operational amplifier U21B, capacitor C32 and resistors R13, R14, R15, R16, R17, R18, R19, R20;

the inverting input end of the operational amplifier U21A is electrically connected with one ends of the resistor R17 and the resistor R19, the non-inverting input end of the operational amplifier U21A is electrically connected with one end of the resistor R18, the output end of the operational amplifier U21A is electrically connected with the other end of the resistor R19 and one end of the resistor R20, the positive power supply input end of the operational amplifier U21A is electrically connected with one ends of the 5V power supply and the capacitor C32, and the negative power supply input end of the operational amplifier U21A is grounded;

the other end of the resistor R17 is electrically connected with one ends of the resistor R15 and the resistor R16, the other end of the resistor R15 is electrically connected with the resistor R13 and the ground wire, the other end of the resistor R13 is electrically connected with one end of the resistor R14, and the other end of the resistor R14 is electrically connected with a 5V power supply and the other end of the resistor R16;

the non-inverting input end of the operational amplifier U21B is electrically connected with the other end of the resistor R20, and the inverting input end of the operational amplifier U21B is electrically connected with the output end of the operational amplifier U21B; the output terminal of the operational amplifier U21B outputs a signal.

Preferably, the total phosphorus temperature measuring circuit comprises the following specific circuits;

operational amplifier U11A, operational amplifier U11B, capacitor C22, and resistors R21, R22, R23, R24, R25, R26, R27, R28;

the inverting input end of the operational amplifier U11A is electrically connected with one ends of the resistor R25 and the resistor R27, the non-inverting input end of the operational amplifier U11A is electrically connected with one end of the resistor R26, the output end of the operational amplifier U11A is electrically connected with the other end of the resistor R27 and one end of the resistor R28, the positive power supply input end of the operational amplifier U11A is electrically connected with one ends of the 5V power supply and the capacitor C22, and the negative power supply input end of the operational amplifier U11A is grounded;

the other end of the resistor R25 is electrically connected with one ends of the resistor R23 and the resistor R24, the other end of the resistor R23 is electrically connected with the resistor R21 and the ground wire, the other end of the resistor R21 is electrically connected with one end of the resistor R22, and the other end of the resistor R22 is electrically connected with a 5V power supply and the other end of the resistor R24;

the non-inverting input end of the operational amplifier U11B is electrically connected with the other end of the resistor R28, and the inverting input end of the operational amplifier U11B is electrically connected with the output end of the operational amplifier U11B; the output terminal of the operational amplifier U11B outputs a signal.

Preferably, the COD temperature measuring circuit comprises a specific circuit;

operational amplifier U1A, operational amplifier U1B, capacitor C12, and resistors R29, R30, R31, R32, R33, R34, R35, R36;

the inverting input end of the operational amplifier U1A is electrically connected with one ends of the resistor R33 and the resistor R35, the non-inverting input end of the operational amplifier U1A is electrically connected with one end of the resistor R34, the output end of the operational amplifier U1A is electrically connected with the other end of the resistor R35 and one end of the resistor R33, the positive power supply input end of the operational amplifier U1A is electrically connected with one ends of the 5V power supply and the capacitor C12, and the negative power supply input end of the operational amplifier U1A is grounded;

the other end of the resistor R33 is electrically connected with one ends of the resistor R31 and the resistor R32, the other end of the resistor R31 is electrically connected with the resistor R29 and the ground wire, the other end of the resistor R29 is electrically connected with one end of the resistor R30, and the other end of the resistor R30 is electrically connected with a 5V power supply and the other end of the resistor R32;

the non-inverting input end of the operational amplifier U1B is electrically connected with the other end of the resistor R32, and the inverting input end of the operational amplifier U1B is electrically connected with the output end of the operational amplifier U1B; the output end of the operational amplifier U1B outputs a signal.

Preferably, the total nitrogen temperature measuring circuit comprises the following specific circuits;

operational amplifier U13A, operational amplifier U13B, capacitor C42, and resistors R37, R38, R39, R40, R41, R42, R43, R44;

the inverting input end of the operational amplifier U13A is electrically connected with one ends of the resistor R41 and the resistor R43, the non-inverting input end of the operational amplifier U13A is electrically connected with one end of the resistor R42, the output end of the operational amplifier U13A is electrically connected with the other end of the resistor R43 and one end of the resistor R41, the positive power supply input end of the operational amplifier U13A is electrically connected with one ends of the 5V power supply and the capacitor C42, and the negative power supply input end of the operational amplifier U13A is grounded;

the other end of the resistor R41 is electrically connected with one ends of the resistor R39 and the resistor R40, the other end of the resistor R39 is electrically connected with the resistor R37 and the ground wire, the other end of the resistor R37 is electrically connected with one end of the resistor R38, and the other end of the resistor R38 is electrically connected with a 5V power supply and the other end of the resistor R40;

the non-inverting input end of the operational amplifier U13B is electrically connected with the other end of the resistor R40, and the inverting input end of the operational amplifier U13B is electrically connected with the output end of the operational amplifier U13B; the output terminal of the operational amplifier U13B outputs a signal.

Compared with the prior art, the microfluidic device for synchronously heating and controlling multiple reagents has the following beneficial effects:

(1) The heating circuit is used for outputting stable voltage to control the working current of the heating wire, so that the reagent is uniformly heated, a plurality of digestion bottles and metal sleeves are used for synchronously heating a plurality of different reagents, and the heating time and the heating cost are reduced;

(2) The temperature sensor is adopted to monitor the temperature of the reagent in real time, so that the temperature of the reagent can be conveniently adjusted according to corresponding conditions.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a multi-reagent synchronous heating control microfluidic device according to the present utility model;

FIG. 2 is a schematic diagram of another configuration of a multi-reagent simultaneous heating control microfluidic device according to the present utility model;

FIG. 3 is a circuit diagram of an ammonia nitrogen heating circuit of the present utility model;

FIG. 4 is a circuit diagram of the total phosphorous heating circuit of the present utility model;

FIG. 5 is a circuit diagram of the COD heating circuit of the present utility model;

FIG. 6 is a circuit diagram of the total nitrogen heating circuit of the present utility model;

FIG. 7 is a graph showing the variation of heating temperature of a multi-reagent synchronous heating control microfluidic device according to the present utility model;

FIG. 8 is a graph showing the fold line change of the heating value of the low and high level corresponding heating values of the micro-fluidic device with the multi-reagent synchronous heating control according to the utility model;

FIG. 9 is a circuit diagram of an ammonia nitrogen temperature measurement circuit of the present utility model;

FIG. 10 is a circuit diagram of a total phosphorus temperature measurement circuit of the present utility model;

FIG. 11 is a circuit diagram of the COD temperature measurement circuit according to the present utility model;

FIG. 12 is a circuit diagram of the total nitrogen thermometry circuit of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will clearly and fully describe the technical aspects of the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, are intended to fall within the scope of the present utility model.

Example 1

1-2, wherein FIG. 1 is an overall structure diagram of the multi-reagent synchronous heating control microfluidic device, and FIG. 2 is an internal structure diagram of the multi-reagent synchronous heating control microfluidic device after removing a metal sleeve, the device comprises:

a plurality of digestion bottles 1, a plurality of metal sleeves 2, a plurality of heating wires 3, a plurality of heating blocks 4 and a plurality of temperature sensors 5;

a plurality of digestion bottles 1, a plurality of metal sleeves 2, a plurality of heating wires 3, a plurality of heating blocks 4 and a plurality of temperature sensors 5;

the digestion bottle 1 is used for placing chemical reagents;

the metal sleeves 2 are arranged in parallel and are arranged on the same support plate, and the installation heights are the same, so that the digestion bottles 1 are placed and quickly heated;

the heating wire 3 is arranged at the bottom of the metal sleeve 2 and is used for uniformly heating the metal sleeve 2;

the heating block 4 is positioned above the heating wire 3 and arranged in the metal sleeve 2 and is used for controlling the temperature of the heating wire 3;

the temperature sensor 5 is located above the heating wire 3 and is at the same height with the heating block 4, is arranged in the metal sleeve 2 and is used for reading the temperature in the sleeve in real time and realizing temperature regulation and control.

4 digestion bottles are respectively filled with ammonia nitrogen, COD (Chemical Oxygen Demand ), total phosphorus and total nitrogen; the number of the metal sleeves 2 is 4;

the number of the heating blocks 4 is 4, and an ammonia nitrogen heating circuit, a COD heating circuit, a total phosphorus heating circuit and a total nitrogen heating circuit are respectively arranged in the 4 heating blocks 4;

the output end of the heating circuit is electrically connected with the heating wire 3, and the working current of the heating wire 3 is controlled, so that the temperature of the heating wire is controlled; the number of the heating wires 3 is 4;

the number of the temperature sensors 5 is 4, and an ammonia nitrogen temperature measuring circuit, a COD temperature measuring circuit, a total phosphorus temperature measuring circuit and a total nitrogen temperature measuring circuit are respectively arranged in the 4 temperature sensors 5;

the 4 digestion bottles 1, the 4 metal sleeves 2, the 4 heating wires 3, the 4 heating blocks 4 and the 4 temperature sensors 5 are sequentially and correspondingly arranged.

The model of the temperature measuring sensor 5 is PT1000, and the temperature in the metal sleeve 2 can be read in real time.

Fig. 3-6 are circuit diagrams of an ammonia nitrogen heating circuit, a total phosphorus heating circuit, a COD heating circuit and a total nitrogen heating circuit of the present utility model, corresponding to 4 input terminals HEATER1, HEATER2, HEATER3, HEATER4 in terms of heating, which are 4 temperature control terminals.

The ammonia nitrogen heating circuit is shown in fig. 3, and the specific circuit comprises;

triode Q1, MOS tube M1 and resistance R1, R2, R3;

the base electrode of the triode Q1 is electrically connected with one ends of a current limiting resistor R1 and a resistor R2, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R2, the collector electrode is electrically connected with the grid electrode of the MOS tube M1 and one end of a resistor R3, the other end of the resistor R3 is electrically connected with a power supply 12V1, the drain electrode of the MOS tube M1 is electrically connected with the power supply 12V1, and the source electrode outputs a voltage VCC12V1 to the heating wire 3.

HEATER1 outputs PWM (Pulse width modulation wave, pulse width modulation) square waves with a duty cycle of 0-100% adjustable and a voltage of 0-3.3V waveform. R1 is a current limiting resistor for driving the base current of the triode Q1, and the triode Q1 adopts a 9013 triode which is used as a switching element for controlling the conduction and non-conduction of the Qce junction. When the Qce junction is on, the voltage at the GNET1 is 0.6V, and at the moment, the Mds junction of the MOS tube M1 is on, and 12V1=VC12V1; when the Qce junction is not conducted, GNET1 is pulled up to 12V1 by the resistor R3, at the moment, the gate voltage and the drain voltage of M1 are the same, the Mds junction is not conducted, the connection of VCC12V1 is suspended and disconnected, and no voltage is output.

Thus, the voltage control of VCC12V1 is controlled to be turned on and off by controlling the PWM output of HEATER 1. The voltage of VCC12V1 is controlled to control the operating current to the heater wire 3, thereby achieving the effect of controlling the temperature of the heater wire 3.

The specific circuits of the other different heating circuits are as follows, and only differ in the control of the working current value output to the heating wire 3, so that the effects of the main components in each heating circuit will not be described in detail.

The total phosphorus heating circuit, as shown in fig. 4, comprises the following specific circuits;

triode Q2, MOS tube M2 and resistance R4, R5, R6;

the base electrode of the triode Q2 is electrically connected with one ends of a current limiting resistor R4 and a resistor R5, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R5, the collector electrode is electrically connected with the grid electrode of the MOS tube M2 and one end of a resistor R6, the other end of the resistor R6 is electrically connected with a power supply 12V2, the drain electrode of the MOS tube M2 is electrically connected with the power supply 12V2, and the source electrode outputs a voltage VCC12V2 to the heating wire 3.

The COD heating circuit is shown in figure 5, and the specific circuit comprises;

triode Q3, MOS tube M3 and resistance R7, R8, R9;

the base electrode of the triode Q3 is electrically connected with one ends of a current limiting resistor R7 and a resistor R8, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R8, the collector electrode is electrically connected with the grid electrode of the MOS tube M3 and one end of a resistor R9, the other end of the resistor R9 is electrically connected with a power supply 12V3, the drain electrode of the MOS tube M3 is electrically connected with the power supply 12V3, and the source electrode outputs a voltage VCC12V3 to the heating wire 3.

The total nitrogen heating circuit, as shown in fig. 6, comprises the following specific circuits;

triode Q4, MOS tube M4 and resistance R10, R11, R12;

the base electrode of the triode Q4 is electrically connected with one ends of a current limiting resistor R10 and a resistor R11, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R11, the collector electrode is electrically connected with the grid electrode of the MOS tube M4 and one end of a resistor R12, the other end of the resistor R12 is electrically connected with a power supply 12V4, the drain electrode of the MOS tube M4 is electrically connected with the power supply 12V4, and the source electrode outputs a voltage VCC12V4 to the heating wire 3.

Ammonia nitrogen: mixing at normal temperature of 25 ℃, and developing at constant temperature of 25 ℃ for 60 minutes;

COD: heating at a high temperature of 165 ℃, and developing at a constant temperature of 25 ℃;

total phosphorus: heating at 125 ℃ for 30 minutes at a high temperature, and developing at 25 ℃ for 15 minutes at a constant temperature;

total nitrogen: heating at 122 deg.C for 30 min, and developing at 25 deg.C.

The duty cycle of the PWM square wave can reach any temperature output as the structure of the 4 heating circuits is the same. Taking HEATER1 for ammonia nitrogen control as an example, ammonia nitrogen is 25 ℃ at normal temperature and is close to normal temperature because of 25 ℃, if the outdoor temperature is higher than 25 ℃, heating is not needed, and if the outdoor temperature is lower than 25 ℃ (assuming that the outdoor temperature is 10 ℃), the following steps are adopted:

1) The first 15 seconds PWM square wave duty cycle is adjusted to 80% and the waiting temperature is rapidly raised to 90% of the target temperature, i.e. 22.5 degrees.

2) The PWM square wave duty cycle is adjusted to 50% and the temperature is waited to rise slowly to the target temperature.

3) The PWM duty cycle is gradually turned down from 50% -10%, and if the target temperature has been reached, the duty cycle output at that time is fixed. If the temperature is already above the target temperature, the duty cycle of the PWM is gradually reduced until the temperature is equal to the target temperature.

4) Other reagent temperatures have corresponding methods, except for the time and the ratio of duty cycle adjustments.

The steps comprise three stages, namely heating, constant temperature and temperature control. The approximate temperature change graph is shown in fig. 7.

PWM has two important parameters: duty cycle and frequency.

1) The duty cycle is calculated from PID (Proportion Integral Differential, proportional-integral-derivative).

2) Another important parameter is frequency: the frequency is too high, the switching loss is increased, and the heating is serious; too low a frequency, the output response speed becomes slow, and the time for the system to reach stability increases.

When the PWM is in a low-frequency working state:

the heating wire 3 is electrified to heat; the heating wire 3 is powered off and is not heated. Therefore, the switching device is controlled by PWM, and the aim of adjusting the power-on time and the power-off time can be achieved by adjusting the duty ratio of PWM.

Since the power-on time or the power-off time of the heating wire 3 becomes long in the case where the frequency is low. For example: if the power-on time is long, the power-off time is correspondingly shortened. The power-on time is long: the heat generated by the heating wire 3 is much; the power-off time is long, the heating value of the heating wire 3 is insufficient, namely, the heating wire 3 starts to heat, and the temperature is not raised yet, so that the heating wire 3 can be powered off.

When the PWM is in a medium-high frequency working state (common medium frequency 20K):

the terminal voltage of the heating wire can be changed by changing the PWM duty ratio.

For example: the duty ratio is turned down, the high level time is reduced, and thus the voltage across the heating wire 3 is reduced, the heat generation amount is reduced, and the heat generation amount line diagram of both is shown in fig. 8, assuming that the time for adjusting the low level (L level) and the high level (H level) is 200ms and 800 ms.

FIGS. 9-12 are circuit diagrams of AN ammonia nitrogen temperature measuring circuit, a total phosphorus temperature measuring circuit, a COD temperature measuring circuit and a total nitrogen temperature measuring circuit of the utility model, and the temperature measuring aspects include 4 outputs of AD_AN, AD_TP, AD_COD and AD_TN, which respectively correspond to 4 reagents of ammonia nitrogen, total phosphorus, COD and total nitrogen.

The ammonia nitrogen temperature measuring circuit, as shown in fig. 9, comprises:

operational amplifier U21A, operational amplifier U21B, capacitor C32 and resistors R13, R14, R15, R16, R17, R18, R19, R20;

the inverting input end of the operational amplifier U21A is electrically connected with one ends of the resistor R17 and the resistor R19, the non-inverting input end of the operational amplifier U21A is electrically connected with one end of the resistor R18, the output end of the operational amplifier U21A is electrically connected with the other end of the resistor R19 and one end of the resistor R20, the positive power supply input end of the operational amplifier U21A is electrically connected with one ends of the 5V power supply and the capacitor C32, and the negative power supply input end of the operational amplifier U21A is grounded;

the other end of the resistor R17 is electrically connected with one ends of the resistor R15 and the resistor R16, the other end of the resistor R15 is electrically connected with the resistor R13 and the ground wire, the other end of the resistor R13 is electrically connected with one end of the resistor R14, and the other end of the resistor R14 is electrically connected with a 5V power supply and the other end of the resistor R16;

the non-inverting input end of the operational amplifier U21B is electrically connected with the other end of the resistor R20, and the inverting input end of the operational amplifier U21B is electrically connected with the output end of the operational amplifier U21B; the output terminal of the operational amplifier U21B outputs a signal.

PTA1 and PTA2 are 2 paths of input ends with the same color of the three-wire system temperature sensor 5, and 3 paths of input ends with different colors are connected with GND.

The resistor R15, the resistor R14, the resistors R16 and R (PTA 1-PTA2 internal resistance difference) form a bridge voltage divider circuit, the voltage differences of the bridge voltage divider circuit are respectively input to the reverse end and the same-direction end of the U21A after passing through the resistor R17 and the resistor R18, the resistor R19 and the resistor R17 form a same-direction amplifying circuit, the amplifying factor g=1+ (R27/R25) =4, the capacitor C32 is a decoupling capacitor, the resistor R20 is a current limiting resistor, the U21B is a radial follower circuit, and the signal intensity of the ad_an is compensated.

The specific circuits of the other different temperature measuring circuits are described below, and only the output compensated signal strength is different, so that the effects of main components in each temperature measuring circuit are not described in detail.

The total phosphorus temperature measurement circuit, as shown in fig. 10, comprises the following specific circuits:

operational amplifier U11A, operational amplifier U11B, capacitor C22, and resistors R21, R22, R23, R24, R25, R26, R27, R28;

the inverting input end of the operational amplifier U11A is electrically connected with one ends of the resistor R25 and the resistor R27, the non-inverting input end of the operational amplifier U11A is electrically connected with one end of the resistor R26, the output end of the operational amplifier U11A is electrically connected with the other end of the resistor R27 and one end of the resistor R28, the positive power supply input end of the operational amplifier U11A is electrically connected with one ends of the 5V power supply and the capacitor C22, and the negative power supply input end of the operational amplifier U11A is grounded;

the other end of the resistor R25 is electrically connected with one ends of the resistor R23 and the resistor R24, the other end of the resistor R23 is electrically connected with the resistor R21 and the ground wire, the other end of the resistor R21 is electrically connected with one end of the resistor R22, and the other end of the resistor R22 is electrically connected with a 5V power supply and the other end of the resistor R24;

the non-inverting input end of the operational amplifier U11B is electrically connected with the other end of the resistor R28, and the inverting input end of the operational amplifier U11B is electrically connected with the output end of the operational amplifier U11B; the output terminal of the operational amplifier U11B outputs a signal.

The COD temperature measuring circuit, as shown in FIG. 11, comprises:

operational amplifier U1A, operational amplifier U1B, capacitor C12, and resistors R29, R30, R31, R32, R33, R34, R35, R36;

the inverting input end of the operational amplifier U1A is electrically connected with one ends of the resistor R33 and the resistor R35, the non-inverting input end of the operational amplifier U1A is electrically connected with one end of the resistor R34, the output end of the operational amplifier U1A is electrically connected with the other end of the resistor R35 and one end of the resistor R33, the positive power supply input end of the operational amplifier U1A is electrically connected with one ends of the 5V power supply and the capacitor C12, and the negative power supply input end of the operational amplifier U1A is grounded;

the other end of the resistor R33 is electrically connected with one ends of the resistor R31 and the resistor R32, the other end of the resistor R31 is electrically connected with the resistor R29 and the ground wire, the other end of the resistor R29 is electrically connected with one end of the resistor R30, and the other end of the resistor R30 is electrically connected with a 5V power supply and the other end of the resistor R32;

the non-inverting input end of the operational amplifier U1B is electrically connected with the other end of the resistor R32, and the inverting input end of the operational amplifier U1B is electrically connected with the output end of the operational amplifier U1B; the output end of the operational amplifier U1B outputs a signal.

The total nitrogen temperature measuring circuit, as shown in fig. 12, comprises the following specific circuits:

operational amplifier U13A, operational amplifier U13B, capacitor C42, and resistors R37, R38, R39, R40, R41, R42, R43, R44;

the inverting input end of the operational amplifier U13A is electrically connected with one ends of the resistor R41 and the resistor R43, the non-inverting input end of the operational amplifier U13A is electrically connected with one end of the resistor R42, the output end of the operational amplifier U13A is electrically connected with the other end of the resistor R43 and one end of the resistor R41, the positive power supply input end of the operational amplifier U13A is electrically connected with one ends of the 5V power supply and the capacitor C42, and the negative power supply input end of the operational amplifier U13A is grounded;

the other end of the resistor R41 is electrically connected with one ends of the resistor R39 and the resistor R40, the other end of the resistor R39 is electrically connected with the resistor R37 and the ground wire, the other end of the resistor R37 is electrically connected with one end of the resistor R38, and the other end of the resistor R38 is electrically connected with a 5V power supply and the other end of the resistor R40;

the non-inverting input end of the operational amplifier U13B is electrically connected with the other end of the resistor R40, and the inverting input end of the operational amplifier U13B is electrically connected with the output end of the operational amplifier U13B; the output terminal of the operational amplifier U13B outputs a signal.

The temperature measurement process is as follows:

1) Taking ammonia nitrogen as AN example, the ad_an needs to collect the temperature only once every 10 seconds during the first 15 seconds of heating, that is, during the heating period.

2) When the temperature is slowly raised to the target temperature, it is necessary to collect the temperature every 1 second.

3) And finally, when the temperature is constant, the sample can be collected once every 5 seconds. Therefore, the temperature rise and constant temperature are not required to be read in real time, the calculation and processing time is saved, and whether the temperature reaches or not can be known in real time when the temperature rises slowly.

The 4 circuits have the same structure and respectively correspond to four different reagents of ammonia nitrogen, total phosphorus, COD and total nitrogen, and the temperature is correspondingly acquired according to the temperature range corresponding to the reagents.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.

Claims (10)

1. A multi-reagent synchronized heating controlled microfluidic device, the device comprising:

a plurality of digestion bottles (1), a plurality of metal sleeves (2) and a plurality of heating wires (3);

the digestion bottle (1) is used for placing chemical reagents;

the metal sleeves (2) are arranged side by side and are used for placing the digestion bottle (1) so as to heat the digestion bottle;

the heating wire (3) is arranged at the bottom of the metal sleeve (2) and is used for heating the metal sleeve (2).

2. A multi-reagent simultaneous heating controlled microfluidic device according to claim 1, further comprising a plurality of heating blocks (4) and a plurality of temperature sensors (5);

the heating block (4) is in signal connection with the heating wire (3) and the temperature sensor (5) and is used for controlling the temperature of the heating wire (3);

the temperature sensor (5) is arranged inside the metal sleeve (2) and is used for detecting the temperature in the metal sleeve (2) in real time and feeding back the temperature to the heating block (4).

3. A multi-reagent synchronous heating control microfluidic device according to claim 2, wherein 4 digestion bottles (1) are respectively filled with ammonia nitrogen, COD, total phosphorus and total nitrogen; the number of the metal sleeves (2) is 4;

the number of the heating blocks (4) is 4, and an ammonia nitrogen heating circuit, a COD heating circuit, a total phosphorus heating circuit and a total nitrogen heating circuit are respectively arranged in the 4 heating blocks (4);

the output end of the heating circuit is electrically connected with the heating wire (3) to control the working current of the heating wire (3) so as to control the temperature of the heating wire; the number of the heating wires (3) is 4;

the number of the temperature sensors (5) is 4, and an ammonia nitrogen temperature measuring circuit, a COD temperature measuring circuit, a total phosphorus temperature measuring circuit and a total nitrogen temperature measuring circuit are respectively arranged in the 4 temperature sensors (5).

4. A multi-reagent simultaneous heating controlled microfluidic device according to claim 3, wherein said ammonia nitrogen heating circuit comprises;

triode Q1, MOS tube M1 and resistance R1, R2, R3;

the base electrode of the triode Q1 is electrically connected with one ends of a current limiting resistor R1 and a resistor R2, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R2, the collector electrode is electrically connected with the grid electrode of the MOS tube M1 and one end of a resistor R3, the other end of the resistor R3 is electrically connected with a power supply 12V1, the drain electrode of the MOS tube M1 is electrically connected with the power supply 12V1, and the source electrode outputs a voltage VCC12V1 to a heating wire (3);

the total phosphorus heating circuit comprises;

triode Q2, MOS tube M2 and resistance R4, R5, R6;

the base electrode of the triode Q2 is electrically connected with one ends of a current limiting resistor R4 and a resistor R5, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R5, the collector electrode is electrically connected with the grid electrode of the MOS tube M2 and one end of a resistor R6, the other end of the resistor R6 is electrically connected with a power supply 12V2, the drain electrode of the MOS tube M2 is electrically connected with the power supply 12V2, and the source electrode outputs a voltage VCC12V2 to a heating wire (3).

5. A multi-reagent simultaneous heating controlled microfluidic device according to claim 3 wherein said COD heating circuit comprises;

triode Q3, MOS tube M3 and resistance R7, R8, R9;

the base electrode of the triode Q3 is electrically connected with one ends of a current limiting resistor R7 and a resistor R8, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R8, the collector electrode is electrically connected with the grid electrode of the MOS tube M3 and one end of a resistor R9, the other end of the resistor R9 is electrically connected with a power supply 12V3, the drain electrode of the MOS tube M3 is electrically connected with the power supply 12V3, and the source electrode outputs a voltage VCC12V3 to a heating wire (3).

6. A multi-reagent simultaneous heating controlled microfluidic device as in claim 3 wherein said total nitrogen heating circuit comprises;

triode Q4, MOS tube M4 and resistance R10, R11, R12;

the base electrode of the triode Q4 is electrically connected with one ends of a current limiting resistor R10 and a resistor R11, the emitter electrode is grounded and is simultaneously electrically connected with the other end of the resistor R11, the collector electrode is electrically connected with the grid electrode of the MOS tube M4 and one end of a resistor R12, the other end of the resistor R12 is electrically connected with a power supply 12V4, the drain electrode of the MOS tube M4 is electrically connected with the power supply 12V4, and the source electrode outputs a voltage VCC12V4 to a heating wire (3).

7. A multi-reagent synchronous heating control microfluidic device according to claim 3, wherein the ammonia nitrogen temperature measuring circuit comprises;

operational amplifier U21A, operational amplifier U21B, capacitor C32 and resistors R13, R14, R15, R16, R17, R18, R19, R20;

the inverting input end of the operational amplifier U21A is electrically connected with one ends of the resistor R17 and the resistor R19, the non-inverting input end of the operational amplifier U21A is electrically connected with one end of the resistor R18, the output end of the operational amplifier U21A is electrically connected with the other end of the resistor R19 and one end of the resistor R20, the positive power supply input end of the operational amplifier U21A is electrically connected with one ends of the 5V power supply and the capacitor C32, and the negative power supply input end of the operational amplifier U21A is grounded;

the other end of the resistor R17 is electrically connected with one ends of the resistor R15 and the resistor R16, the other end of the resistor R15 is electrically connected with the resistor R13 and the ground wire, the other end of the resistor R13 is electrically connected with one end of the resistor R14, and the other end of the resistor R14 is electrically connected with a 5V power supply and the other end of the resistor R16;

the non-inverting input end of the operational amplifier U21B is electrically connected with the other end of the resistor R20, and the inverting input end of the operational amplifier U21B is electrically connected with the output end of the operational amplifier U21B; the output terminal of the operational amplifier U21B outputs a signal.

8. A multi-reagent synchronous heating control microfluidic device according to claim 3, wherein said total phosphorus temperature measurement circuit comprises;

operational amplifier U11A, operational amplifier U11B, capacitor C22, and resistors R21, R22, R23, R24, R25, R26, R27, R28;

the inverting input end of the operational amplifier U11A is electrically connected with one ends of the resistor R25 and the resistor R27, the non-inverting input end of the operational amplifier U11A is electrically connected with one end of the resistor R26, the output end of the operational amplifier U11A is electrically connected with the other end of the resistor R27 and one end of the resistor R28, the positive power supply input end of the operational amplifier U11A is electrically connected with one ends of the 5V power supply and the capacitor C22, and the negative power supply input end of the operational amplifier U11A is grounded;

the other end of the resistor R25 is electrically connected with one ends of the resistor R23 and the resistor R24, the other end of the resistor R23 is electrically connected with the resistor R21 and the ground wire, the other end of the resistor R21 is electrically connected with one end of the resistor R22, and the other end of the resistor R22 is electrically connected with a 5V power supply and the other end of the resistor R24;

the non-inverting input end of the operational amplifier U11B is electrically connected with the other end of the resistor R28, and the inverting input end of the operational amplifier U11B is electrically connected with the output end of the operational amplifier U11B; the output terminal of the operational amplifier U11B outputs a signal.

9. A multi-reagent synchronous heating control microfluidic device according to claim 3, wherein the COD temperature measurement circuit comprises;

operational amplifier U1A, operational amplifier U1B, capacitor C12, and resistors R29, R30, R31, R32, R33, R34, R35, R36;

the inverting input end of the operational amplifier U1A is electrically connected with one ends of the resistor R33 and the resistor R35, the non-inverting input end of the operational amplifier U1A is electrically connected with one end of the resistor R34, the output end of the operational amplifier U1A is electrically connected with the other end of the resistor R35 and one end of the resistor R33, the positive power supply input end of the operational amplifier U1A is electrically connected with one ends of the 5V power supply and the capacitor C12, and the negative power supply input end of the operational amplifier U1A is grounded;

the other end of the resistor R33 is electrically connected with one ends of the resistor R31 and the resistor R32, the other end of the resistor R31 is electrically connected with the resistor R29 and the ground wire, the other end of the resistor R29 is electrically connected with one end of the resistor R30, and the other end of the resistor R30 is electrically connected with a 5V power supply and the other end of the resistor R32;

the non-inverting input end of the operational amplifier U1B is electrically connected with the other end of the resistor R32, and the inverting input end of the operational amplifier U1B is electrically connected with the output end of the operational amplifier U1B; the output end of the operational amplifier U1B outputs a signal.

10. A multi-reagent simultaneous heating controlled microfluidic device as in claim 3 wherein said total nitrogen thermometry circuit comprises;

operational amplifier U13A, operational amplifier U13B, capacitor C42, and resistors R37, R38, R39, R40, R41, R42, R43, R44;

the inverting input end of the operational amplifier U13A is electrically connected with one ends of the resistor R41 and the resistor R43, the non-inverting input end of the operational amplifier U13A is electrically connected with one end of the resistor R42, the output end of the operational amplifier U13A is electrically connected with the other end of the resistor R43 and one end of the resistor R41, the positive power supply input end of the operational amplifier U13A is electrically connected with one ends of the 5V power supply and the capacitor C42, and the negative power supply input end of the operational amplifier U13A is grounded;

the other end of the resistor R41 is electrically connected with one ends of the resistor R39 and the resistor R40, the other end of the resistor R39 is electrically connected with the resistor R37 and the ground wire, the other end of the resistor R37 is electrically connected with one end of the resistor R38, and the other end of the resistor R38 is electrically connected with a 5V power supply and the other end of the resistor R40;

the non-inverting input end of the operational amplifier U13B is electrically connected with the other end of the resistor R40, and the inverting input end of the operational amplifier U13B is electrically connected with the output end of the operational amplifier U13B; the output terminal of the operational amplifier U13B outputs a signal.