Non-immersive cross-modal pressure detection system

Abstract

The application provides a non-immersed transmembrane pressure detection system, which is characterized in that: a liquid inlet detection module, a permeation end detection module, a backflow end detection module and a transmembrane pressure calculation module are arranged, a non-immersed transmembrane pressure detection circuit is arranged in each of the liquid inlet detection module, the permeation end detection module and the backflow end detection module, the corresponding transmembrane pressure calculation result is obtained by calculating the liquid inlet detection signal, the permeation end detection signal and the backflow end detection signal output by the circuit, a four-stage amplification and analog signal isolation circuit composed of a high-precision resistance voltage division network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optical coupler, a third-stage operational amplifier circuit and a fourth-stage operational amplifier circuit is arranged in the non-immersed transmembrane pressure detection circuit, the detected current signal is converted into an electrical signal by using the operational amplification piezoelectric effect, and the piezoelectric type can provide an anti-interference signal electrical output after isolation chip. The application has good linearity, simple circuit calculation and effectively solves the problem of electrical signal isolation between an analog signal and a single-chip microcomputer application system.

Description

Technical Field

[0001] This invention relates to the field of pressure testing, and in particular to a non-immersion cross-molding pressure testing system. Background Technology

[0002] Current methods for detecting pressure values ​​are simple but lack precision. Inaccurate data readings are often due to poor signal interference handling. This is especially true for non-contact liquid pressure measurement, where precise readings are difficult. Existing non-contact liquid pressure detection solutions primarily rely on direct data reading and signal amplification, but this computational approach to electrical signal output fails to provide signal isolation and interference immunity, even with advancements in new materials technology. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a non-immersion cross-molding detection circuit to solve the problems of the prior art.

[0004] To achieve the above and other related objectives, the present invention provides a non-immersion transmembrane pressure detection system, the system comprising: an inlet end detection module, a permeate end detection module, a return end detection module, and a transmembrane pressure calculation module; wherein, the inlet end detection module, the permeate end detection module, and the return end detection module are each equipped with a non-immersion transmembrane pressure detection circuit; the inlet end detection module is used to output a corresponding inlet end detection signal based on the input signal of the corresponding inlet end; the permeate end detection module is used to output a corresponding permeate end detection signal based on the input signal of the corresponding permeate end; The reflux detection module is used to output a corresponding reflux detection signal based on the input signal of the corresponding reflux end; the transmembrane pressure calculation module is connected to the liquid inlet detection module, the permeate detection module and the reflux detection module, and is used to perform transmembrane pressure calculation based on the liquid inlet detection signal, the permeate detection signal and the reflux detection signal to obtain the corresponding transmembrane pressure calculation result; and each non-immersion transmembrane pressure detection circuit includes: a high-precision resistor voltage divider network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optocoupler, a third-stage operational amplifier circuit and a fourth-stage operational amplifier circuit.

[0005] In one embodiment of the present invention, each non-immersion transmodulation detection circuit comprises a first circuit module consisting of a high-precision resistor divider network and a first-stage operational amplifier circuit; a second circuit module consisting of a negative feedback network formed by a second-stage operational amplifier circuit and a linear optocoupler; and a third and fourth circuit modules consisting of a third and a fourth-stage operational amplifier circuit, respectively. The first, second, third, and fourth circuit modules are connected in series. The corresponding input signal is divided by the high-precision resistor divider network in the first circuit module and then amplified by the first-stage operational amplifier circuit to obtain a first signal. The first signal is input to the second... The circuit module consists of a second-stage operational amplifier circuit and a linear optocoupler for second-stage amplification and optocoupler isolation, respectively, to obtain a second signal and output a corresponding output signal. The output signal from the second circuit module is passed through a third circuit module to obtain a third signal, which is then amplified by a third-stage operational amplifier circuit to obtain a fourth and a fifth signal. The fourth signal is input to a fourth circuit module, where it is amplified by a fourth-stage operational amplifier circuit to output a corresponding detection signal. After isolation, the signal values ​​of the first, second, and third signals are equal. The signal value of the corresponding detection signal is calculated based on the signal value of the fourth signal, which is related to the signal value of the third signal.

[0006] In one embodiment of the present invention, the first circuit module includes: a first resistor, a second resistor, a first-stage operational amplifier, a third resistor, a fourth resistor, a fifth resistor, and a first capacitor; wherein, one end of the first resistor is connected to a signal input terminal for inputting an input signal, and the other end is connected to one end of the second resistor and the positive input pin of the first-stage operational amplifier; the other end of the second resistor is grounded; one end of the third resistor is connected to the inverting input pin of the first-stage operational amplifier and one end of the fourth resistor, and the other end is grounded; the other end of the fourth resistor is connected to the output pin of the first-stage operational amplifier and one end of the fifth resistor; the other end of the fifth resistor is connected to the second circuit module; one end of the first capacitor is connected to a power supply and the positive power supply pin of the first-stage operational amplifier. One end is grounded; the first resistor and the second resistor form a high-precision resistor voltage divider network, used to divide the input signal to obtain a sampled signal which is then input to the first-stage operational amplifier; the first-stage operational amplifier, the third resistor, the fourth resistor, the fifth resistor, and the first capacitor form a first-stage operational amplifier circuit, used to perform first-stage amplification through the first-stage amplifier, and the amplification factor is adjusted by the fourth resistor. The amplified signal is then current-limited by the fifth resistor to obtain a first signal which is transmitted to the second circuit module; and wherein, the signal value of the sampled signal satisfies a first numerical relationship with the input signal value, the first resistor value, and the second resistor value; the signal value of the first signal satisfies a second numerical relationship with the signal value of the sampled signal, the third resistor value, and the fourth resistor value.

[0007] In one embodiment of the present invention, the first numerical relationship includes: Vin1 = Vin × (R1 × R2 / R1 + R2); where Vin1 is the signal value of the acquired signal, Vin is the input signal value, R1 is the first resistance value, and R2 is the second resistance value; the second numerical relationship includes: Out1 = (R4 / R3 + 1) × Vin1; where Out1 is the signal value of the first signal, Vin1 is the signal value of the acquired signal, R3 is the third resistance value, and R4 is the fourth resistance value.

[0008] In one embodiment of the present invention, the second circuit module includes: a linear optocoupler, a second-stage operational amplifier, a sixth resistor, and a second capacitor for placing the circuit to generate oscillations; wherein, the positive input pin of the second-stage operational amplifier is connected to ground, its negative input pin is connected to one end of the second capacitor, and its output pin is connected to the other end of the second capacitor and one end of the sixth resistor; the linear optocoupler includes: a light-emitting diode, a first photodiode, and a second light-emitting diode; the anode pin of the light-emitting diode is connected to the power supply, and the cathode pin is connected to the other end of the sixth resistor; the anode pin of the first photodiode is grounded, and the cathode pin is connected to the other end of the fifth resistor; the anode pin of the second photodiode is grounded, and the cathode pin is connected to the third circuit module; the second-stage operational amplifier, the sixth resistor, and the second capacitor constitute a second-stage operational amplifier circuit for negative feedback amplification, used to amplify the input first signal in the second stage to obtain a second signal, and input it to the linear optocoupler; the linear optocoupler performs optical isolation based on the input first signal and the second signal and outputs a corresponding output signal.

[0009] In one embodiment of the present invention, the third-stage operational amplifier circuit of the signal amplification module includes: a high-precision operational amplifier, a seventh resistor, a precision operational amplifier chip, an eighth resistor, a ninth resistor, a tenth resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, and a first sliding rheostat; wherein, one end of the seventh resistor is connected to the cathode pin of the second light-emitting diode of the linear optocoupler, and the other end is connected to one end of the fourth capacitor and a negative input pin of the high-precision operational amplifier; the other negative input pin of the high-precision operational amplifier is connected to one of its own positive input pins via the first sliding rheostat, and its other positive input pin is grounded; its output pin is connected to the other end of the fourth capacitor and one end of the eighth resistor; its positive power supply pin is connected to the power supply voltage terminal; one of its negative power supply pins is connected to the sixth capacitor with one end grounded and the negative voltage power supply terminal; and the other negative power supply pin is connected to the output pin and a negative input pin of the precision operational amplifier chip. The other end of the eighth resistor is connected to one end of the fifth capacitor and the fourth circuit module; the other end of the fifth capacitor is grounded; the positive input pin of the precision operational amplifier chip is connected to the connection terminals of the ninth and tenth resistors; the other end of the ninth resistor is connected to the power supply voltage terminal, and the other end of the tenth resistor is connected to the negative voltage power supply; the output signal output from the second circuit module is current-limited by the seventh resistor and then input to the high-precision operational amplifier, and the amplification factor is adjusted by the first sliding rheostat and the low-frequency interference generated by the front-end signal is eliminated by the fourth capacitor to obtain the fourth signal; and the fifth signal is obtained by the precision operational amplifier chip based on the input voltage adjusted by the ninth and tenth resistors to input a precise signal reference value; and wherein the signal value of the fifth signal satisfies the third numerical relationship with the value of the ninth resistor and the value of the tenth resistor; the signal value of the fourth signal satisfies the fourth numerical relationship with the resistance adjustment value of the first sliding rheostat and the signal value of the third signal.

[0010] In one embodiment of the present invention, the third numerical relationship includes: Out5 = VDD × (R9 × R10 / R9 + R10); where Out5 is the signal value of the fifth signal, VDD is the power supply voltage value, R92 is the ninth resistance value, and R10 is the tenth resistance value; the fourth numerical relationship includes: Out4 = ((49.4K / Rg) + 1) × Out3; where Out4 is the signal value of the fourth signal, Out5 is the signal value of the fifth signal, and Rg is the adjustment resistance value of the first sliding rheostat.

[0011] In one embodiment of the present invention, the fourth stage operational amplifier circuit of the fourth circuit module includes: an eleventh resistor, a fourth stage operational amplifier, a sixth capacitor, a second sliding rheostat, and a twelfth resistor; wherein, a positive input pin of the fourth stage operational amplifier is connected to an eighth resistor, a negative input pin is connected to one end of the eleventh resistor, one end of the second sliding rheostat, and one end of the sixth capacitor, and its output pin is connected to one end of the twelfth resistor; the other end of the eleventh resistor is grounded; the other end of the second sliding rheostat is connected to the other end of the sixth capacitor and one end of the twelfth resistor; the other end of the twelfth resistor outputs a corresponding detection signal; the fourth stage operational amplifier biases and amplifies the input fourth signal, while the second sliding rheostat adjusts the amplification factor, and the sixth capacitor eliminates low-frequency interference generated by the front-end signal; the amplified signal is current-limited by the twelfth resistor to obtain a detection signal and output; and wherein the signal value of the detection signal satisfies a fifth numerical relationship with the signal value of the fourth signal, the adjustment resistance value of the eleventh resistor, and the adjustment resistance value of the second sliding rheostat.

[0012] In one embodiment of the present invention, the fifth numerical relationship includes: Out6 = ((R13 / R11+1) × Out4); where Out6 is the signal value of the detection signal, Out4 is the signal value of the fourth signal, R11 is the eleventh resistance value, and R13 is the adjustment resistance value of the second sliding rheostat.

[0013] In one embodiment of the present invention, the transmembrane pressure calculation based on the inlet end detection signal, the permeate end detection signal, and the return end detection signal to obtain the corresponding transmembrane pressure calculation result includes: calculating the corresponding transmembrane pressure calculation result based on the pressure detection values ​​of the inlet end detection signal, the permeate end detection signal, and the return end detection signal according to the transmembrane pressure calculation formula; wherein, the transmembrane pressure calculation formula is: V=(V1+V3) / 2-V2; and wherein, V is the transmembrane pressure calculation result, V1 is the pressure detection value of the inlet end detection signal, V2 is the pressure detection value of the permeate end detection signal, and V3 is the pressure detection value of the return end detection signal.

[0014] As described above, this invention is a non-immersion transmembrane pressure detection system with the following advantages: This invention sets up an inlet detection module, a through-flow detection module, a return-flow detection module, and a transmembrane pressure calculation module. Furthermore, it incorporates a non-immersion transmembrane pressure detection circuit in each of these modules, enabling transmembrane pressure calculation based on the inlet, through, and return-flow detection signals output by each circuit. Additionally, by incorporating a high-precision resistor voltage divider network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optocoupler, a third-stage operational amplifier circuit, and a fourth-stage operational amplifier circuit within the non-immersion transmembrane pressure detection circuit, and using a four-stage amplification and analog signal isolation circuit, it converts the detected current signal into an electrical signal using the piezoelectric effect of operational amplification. This signal is then piezoelectrically isolated by an isolation chip to provide an anti-interference electrical output. This invention not only offers good linearity and simple circuit calculations but also effectively solves the problem of electrical signal isolation between analog signals and microcontroller application systems. Attached Figure Description

[0015] Figure 1 The diagram shown is a structural schematic of a non-immersion cross-molding testing system according to an embodiment of the present invention.

[0016] Figure 2 The diagram shown is a structural schematic of a non-immersion cross-molding detection circuit according to an embodiment of the present invention.

[0017] Figure 3 The diagram shown is a structural schematic of a non-immersion cross-molding detection circuit according to an embodiment of the present invention.

[0018] Figure 4 A shows the numerical relationship between the detection results of the inlet, permeation, and reflux ends at different rotation speeds in a normal column state according to an embodiment of the present invention.

[0019] Figure 4 B shows the numerical relationship between the detection results of the inlet, through, and return ends at different rotation speeds in a blocked state according to an embodiment of the present invention.

[0020] Figure 5 A shows a comparison chart of the detection results at the inlet end under normal and blocked conditions in an embodiment of the present invention.

[0021] Figure 5 B shows a comparison chart of the detection results at the liquid outlet under normal and blocked conditions in one embodiment of the present invention. Detailed Implementation

[0022] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0023] It should be noted that in the following description, reference is made to the accompanying drawings, which illustrate several embodiments of the invention. It should be understood that other embodiments may also be used, and changes in mechanical composition, structure, electrical system, and operation may be made without departing from the spirit and scope of the invention. The following detailed description should not be considered limiting, and the scope of the embodiments of the invention is defined only by the claims of the published patents. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Spatially related terms, such as “upper,” “lower,” “left,” “right,” “below,” “below,” “lower part,” “above,” “upper part,” etc., may be used herein to illustrate the relationship between one element or feature shown in the figures and another element or feature.

[0024] Throughout this specification, when it is said that a part is "connected" to another part, this includes not only "direct connection" but also "indirect connection" by placing other elements in between. Furthermore, when it is said that a part "includes" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather means that other constituent elements may also be included.

[0025] The terms "first," "second," and "third," etc., used herein are for the purpose of describing various parts, components, regions, layers, and / or segments, but are not limiting. These terms are used only to distinguish one part, component, region, layer, or segment from others. Therefore, the "first part," "component," "region," "layer," or "segment" described below may refer to a "second part," "component," "region," "layer," or "segment" without departing from the scope of this invention.

[0026] Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of the stated feature, operation, element, component, item, kind, and / or group, but do not preclude the presence, occurrence, or addition of one or more other features, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition arise only when combinations of elements, functions, or operations are inherently mutually exclusive in some manner.

[0027] This invention provides a non-immersion transmembrane pressure detection system. It comprises an inlet detection module, a through-flow detection module, a return-flow detection module, and a transmembrane pressure calculation module. Each of these modules has a non-immersion transmembrane pressure detection circuit. The system calculates the transmembrane pressure based on the inlet, through, and return-flow detection signals output by each circuit. Furthermore, the non-immersion transmembrane pressure detection circuit incorporates a four-stage amplification circuit consisting of a high-precision resistor voltage divider network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optocoupler, a third-stage operational amplifier circuit, and a fourth-stage operational amplifier circuit. This circuit also includes an analog signal isolation circuit, which utilizes the piezoelectric effect of operational amplification to convert the detected current signal into an electrical signal. The piezoelectric isolation chip then provides an anti-interference electrical output signal. This invention not only offers good linearity and simple circuit calculations but also effectively solves the problem of electrical signal isolation between analog signals and microcontroller application systems.

[0028] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can readily implement it. The present invention can be embodied in many different forms and is not limited to the embodiments described herein.

[0029] like Figure 1 A schematic diagram of a non-immersion cross-molding testing system according to an embodiment of the present invention is shown.

[0030] The non-immersion cross-molding pressure detection system can be widely used for the measurement and control of pressure, height, gas and liquid flow rate, velocity, level, and pressure. In addition, it is widely applied in water conservancy, geology, meteorology, chemical engineering, and medical fields. Especially for non-contact liquid and gas hose pressure sensors, due to their thinness, high sensitivity, simple actuation, and ease of calculation, they are widely used in high-power, low-power scenarios.

[0031] The non-immersion cross-molding inspection system includes:

[0032] Inlet detection module 1, permeation detection module 2, return detection module 3, and transmembrane pressure calculation module 4;

[0033] The liquid inlet detection module 101, the through-end detection module 102, and the return-end detection module 103 are each equipped with a non-immersion cross-molding detection circuit.

[0034] The liquid inlet detection module 101 is used to output a corresponding liquid inlet detection signal based on the input signal of the corresponding liquid inlet through a non-immersion cross-molding detection circuit.

[0035] The transmission end detection module 102 is used to output a corresponding transmission end detection signal based on the input signal of the corresponding transmission end through a non-immersion cross-molding detection circuit.

[0036] The return end detection module 103 is used to output a corresponding return end detection signal based on the input signal of the corresponding return end through a non-immersion cross-molding detection circuit;

[0037] The transmembrane pressure calculation module 104 is connected to the inlet end detection module 101, the permeate end detection module 102 and the return end detection module 103. It is used to perform transmembrane pressure calculation based on the inlet end detection signal, the permeate end detection signal and the return end detection signal to obtain the corresponding transmembrane pressure calculation result.

[0038] Furthermore, each non-immersion transmodulation detection circuit includes: a high-precision resistor divider network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optocoupler, a third-stage operational amplifier circuit, and a fourth-stage operational amplifier circuit.

[0039] To better describe the non-immersion cross-molding detection system, the following embodiments are used to specifically describe the structure of the non-immersion cross-molding detection circuit.

[0040] In one embodiment, such as Figure 2 As shown, the non-immersion cross-molding detection circuit includes:

[0041] High-precision resistor divider network 1, first-stage operational amplifier circuit 2, second-stage operational amplifier circuit 3, linear optocoupler 4, third-stage operational amplifier circuit 5, and fourth-stage operational amplifier circuit 6;

[0042] The circuit consists of a high-precision resistor divider network 1 and a first-stage operational amplifier circuit 2 forming the first circuit module; a second circuit module consists of a negative feedback network formed by a second-stage operational amplifier circuit 3 and a linear optocoupler 4 forming the second circuit module; and a third circuit module consists of a third-stage operational amplifier circuit 5 and a fourth-stage operational amplifier circuit 6 forming the third and fourth circuit modules, respectively. The first, second, third, and fourth circuit modules are connected in series sequentially.

[0043] The corresponding input signal Vin is divided by the high-precision resistor voltage divider network 1 in the first circuit module and then amplified by the first operational amplifier circuit 2 to obtain the first signal Out1. The first signal Out1 is input to the second circuit module, where it is amplified and optically isolated by the second operational amplifier circuit 3 and the linear optocoupler 4 to obtain the second signal Out2 and output the corresponding output signal. The output signal from the second circuit module is amplified by the third circuit module to obtain the third signal Out3, and then amplified by the third operational amplifier circuit to obtain the fourth signal Out4 and the fifth signal Out5. The fourth signal Out4 is input to the fourth circuit module, amplified by the fourth operational amplifier circuit to output the final detection signal Out6.

[0044] After isolation, the signal values ​​of the first signal Out1, the second signal Out2, and the third signal Out3 are equal; the signal value of the detection signal Out6 is calculated based on the signal value of the fourth signal Out4, which is related to the signal value of the third signal Out3, so that the pressure detection value of the corresponding detection signal can be obtained.

[0045] To better describe the non-immersion cross-molding detection circuit, the following is combined with... Figure 3 Please provide a detailed explanation.

[0046] In one embodiment, such as Figure 3 The first circuit module includes: a first resistor R1, a second resistor R2, a first-stage operational amplifier U2A, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a first capacitor C1;

[0047] In this circuit, one end of the first resistor R1 is connected to the signal input terminal for inputting the input signal, and the other end is connected to one end of the second resistor R2 and the positive input pin 3 of the first-stage operational amplifier U2A; the other end of the second resistor R2 is grounded; one end of the third resistor R3 is connected to the inverting input pin 2 of the first-stage operational amplifier U2A and one end of the fourth resistor R4, and the other end is grounded; the other end of the fourth resistor R4 is connected to the output pin 1 of the first-stage operational amplifier U2A and one end of the fifth resistor; the other end of the fifth resistor is connected to the second circuit module; and one end of the first capacitor is connected to the power supply and the positive power supply pin 8 of the first-stage operational amplifier U2A, and the other end is grounded; the negative power supply pin 4 of the first-stage operational amplifier U2A;

[0048] The first resistor R1 and the second resistor R2 form a high-precision resistor voltage divider network, used to divide the input signal Vin to obtain the acquired signal Vin1, which is input to the positive input pin 3 of the first-stage operational amplifier U2A. The first-stage operational amplifier U2A, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the first capacitor C1 constitute the first-stage operational amplifier circuit, used for first-stage amplification by the first-stage amplifier U2A, and the amplification factor is adjusted by the fourth resistor R4 to obtain a suitable value. The calculation formula is as follows:

[0049] Av=uo / ui=(R4+R3) / R3=R4 / R3+1; (1)

[0050] The amplified signal is then passed through the fifth resistor to limit the current, resulting in the first signal which is then transmitted to the second circuit module.

[0051] Furthermore, the signal value of the acquired signal satisfies a first numerical relationship with the input signal value, the first resistance value, and the second resistance value; and the signal value of the first signal satisfies a second numerical relationship with the signal value of the acquired signal, the third resistance value, and the fourth resistance value.

[0052] In one embodiment, the first numerical relationship includes:

[0053] Vin1=Vin×(R1×R2 / R1+R2); (2)

[0054] Wherein, Vin1 is the signal value of the acquired signal, Vin is the input signal value, R1 is the first resistance value, and R2 is the second resistance value;

[0055] The second numerical relationship includes:

[0056] Out1 = (R4 / R3 + 1) × Vin1; (3)

[0057] Where Out1 is the signal value of the first signal, Vin1 is the signal value of the acquired signal, R3 is the third resistance value, and R4 is the fourth resistance value.

[0058] In one embodiment, the second circuit module includes: a linear optocoupler U3, a second-stage operational amplifier U2B, a sixth resistor R6, and a second capacitor C2;

[0059] In this circuit, the positive input pin 5 of the second-stage operational amplifier U2B is connected to ground, its negative input pin 6 is connected to one end of the second capacitor C2, and its output pin 7 is connected to the other end of the second capacitor C2 and one end of the sixth resistor R6. The linear optocoupler U3 includes: a light-emitting diode (LED), a first photodiode IPD1, and a second light-emitting diode (IPD2). The anode pin 2 of the LED is connected to the power supply, and the cathode pin 1 is connected to the other end of the sixth resistor R6. The anode pin 4 of the first photodiode IPD1 is grounded, and the cathode pin 3 is connected to the other end of the fifth resistor R5. The anode pin 5 of the second photodiode IPD2 is grounded, and the cathode pin 6 is connected to the third circuit module.

[0060] The second-stage operational amplifier U2B, the sixth resistor R6, and the second capacitor C2 constitute the second-stage operational amplifier circuit for negative feedback amplification. It is used to amplify the input first signal Out1 in the second stage to obtain the second signal Out2, and input it to the linear optocoupler U3. The linear optocoupler performs optical isolation based on the input first signal Out1 and the second signal Out2 and outputs the corresponding output signal.

[0061] The second capacitor C2 can prevent circuit oscillations, filter out glitches in the circuit, and prevent damage to the LED in the linear optocoupler. However, in high-frequency circuits, the second capacitor C2 will affect the channel gain. The appropriate capacitance value can be selected according to the operating frequency. The value of R6 will affect the LED luminous intensity, thus playing a certain role in the channel gain.

[0062] In one embodiment, the third-stage operational amplifier circuit of the signal amplification module includes: a high-precision operational amplifier U4, a seventh resistor R7, a precision operational amplifier chip U5, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a first sliding rheostat RG.

[0063] In this circuit, one end of the seventh resistor R7 is connected to the cathode pin 6 of the second light-emitting diode IPD2 of the linear optocoupler U3, and the other end is connected to one end of the fourth capacitor C4 and the negative input pin 2 of the high-precision operational amplifier U4. The negative input pin 8 of the high-precision operational amplifier U4 is connected to its own positive input pin 1 through the first sliding rheostat RG. Its positive input pin 3 is grounded. Its output pin 6 is connected to the other end of the fourth capacitor C4 and one end of the eighth resistor R8. Its positive power supply pin 7 is connected to the power supply voltage terminal VDD. Its negative power supply pin 4 is connected to the sixth capacitor C6, which is grounded at one end, and the negative voltage power supply terminal VEE. Its negative power supply pin 5 is connected to the output pin 6 and the negative input pin 2 of the precision operational amplifier chip U5. The other end of the eighth resistor R8 is connected to one end of the fifth capacitor C5 and the fourth circuit module. The other end of the fifth capacitor C5 is grounded. The positive input pin 3 of the precision operational amplifier chip is connected to the connection terminals of the ninth resistor R9 and the tenth resistor R10. The other end of the ninth resistor R9 is connected to the power supply voltage terminal VDD, and the other end of the tenth resistor is connected to the negative voltage power supply VEE.

[0064] The output signal from the second circuit module is current-limited by the seventh resistor R7 and then input to the high-precision operational amplifier U4. The amplification factor is adjusted by the first sliding rheostat RG and the low-frequency interference generated by the front-end signal is eliminated by the fourth capacitor C4 to obtain the fourth signal Out. The fifth signal Out5 is obtained by the precision operational amplifier chip U5 based on the input voltage reference value adjusted by the ninth resistor R9 and the tenth resistor R10.

[0065] The signal flows through the current-limiting resistor R7 to the input U4. C4 is used to eliminate low-frequency interference generated by the front-end signal. RG is used to adjust the amplification factor, which can be amplified from 1 to 1000 times. The amplification factor is calculated as gain G = (49.4K / Rg) + 1. U5 is used to input a precise signal reference value. R9 and R10 are used to adjust the input voltage. Through the follower formed by itself, the input and output are equal.

[0066] Furthermore, the signal value of the fifth signal Out5 satisfies the third numerical relationship with the ninth and tenth resistance values; the signal value of the fourth signal satisfies the fourth numerical relationship with the resistance adjustment value of the first sliding rheostat and the signal value of the third signal.

[0067] In one embodiment, the third numerical relationship includes:

[0068] Out5=VDD×(R9×R10 / R9+R10); (4)

[0069] Where Out5 is the signal value of the fifth signal, VDD is the power supply voltage value, R92 is the ninth resistor value, and R10 is the tenth resistor value;

[0070] The fourth numerical relationship includes:

[0071] Out4=((49.4K / Rg)+1)×Out3; (5)

[0072] Where Out4 is the signal value of the fourth signal, Out5 is the signal value of the fifth signal, and Rg is the adjustment resistance value of the first sliding rheostat.

[0073] In one embodiment, the fourth operational amplifier circuit of the fourth circuit module includes:

[0074] The eleventh resistor R11, the fourth operational amplifier U1, the sixth capacitor C6, the second sliding rheostat R13, and the twelfth resistor R12;

[0075] In this configuration, the positive input pin 3 of the fourth-stage operational amplifier U1 is connected to the eighth resistor, its inverting input pin 2 is connected to one end of the eleventh resistor R11, one end of the second sliding rheostat R13, and one end of the sixth capacitor C6, and its output pin 6 is connected to one end of the twelfth resistor R12; the other end of the eleventh resistor R11 is grounded, the positive power supply pin 7 is connected to the power supply voltage terminal VDD, and the negative power supply pin 4 is connected to the negative voltage power supply terminal VEE; the other end of the second sliding rheostat R13 is connected to the other end of the sixth capacitor C6 and one end of the twelfth resistor R12; the other end of the twelfth resistor R12 outputs a detection signal.

[0076] The fourth operational amplifier U1 biases and amplifies the input fourth signal Out4. At the same time, the second sliding rheostat R13 adjusts the amplification factor, and the sixth capacitor C6 eliminates the low-frequency interference generated by the front-end signal. After the amplified signal is current-limited by the twelfth resistor R12, the detection signal Out6 is obtained and output.

[0077] The fourth operational amplifier U1 is an isolated back-end two-stage amplifier. The more amplification stages, the more accurate the signal. C6 is used to eliminate low-frequency interference generated by the front-end signal, R13 is used to adjust the amplification factor, and R12 is used for current limiting.

[0078] Furthermore, the signal value of the detection signal satisfies the fifth numerical relationship with the signal value of the fourth signal, the eleventh resistor, and the adjustment resistance value of the second sliding rheostat.

[0079] In one embodiment, the fifth numerical relationship includes:

[0080] Out6=((R13 / R11+1)×Out4); (6)

[0081] Where Out6 is the signal value of the detection signal, Out4 is the signal value of the fourth signal, R11 is the eleventh resistance value, and R13 is the adjustment resistance value of the second sliding rheostat.

[0082] In one embodiment, the first-stage operational amplifier U2A and the second-stage operational amplifier U2B are LM358 amplifiers; the high-precision operational amplifier U4 is an AD620ANZ amplifier; the precision operational amplifier chip U5 is a precision operational OP1177ARZ chip; and the fourth-stage operational amplifier U1 is an OP27GSZ-REEL operational amplifier.

[0083] In one embodiment, the linear optical coupler U3 is an HCNR200 / HCNR201 optical coupler.

[0084] Next, the calculation principle of the transmembrane pressure calculation result will be explained in detail with reference to the following embodiments.

[0085] In one embodiment, specific experiments were conducted, as shown in Table 1, to detect the pressure values ​​at the inlet, permeate, reflux, and transmembrane ends under normal column conditions and under blocked column conditions.

[0086] Table 1: Test results under normal column conditions and under blocked column conditions

[0087]

[0088] Based on the analysis of the contents of this test result table, it can be seen that, Figure 4 A represents the numerical relationship between the test results at different rotational speeds for the inlet, permeate, and reflux ends under normal column conditions; for example... Figure 4 B shows the numerical relationship of the test results at different rotational speeds for the inlet, through, and return ends under the blocked column condition. It can be seen that the linear trends in both graphs are the same, and both correspond to the formula: cross-molding data = (inlet end + return end) / 2 - through end. Further comparison... Figure 5 The numerical relationship between the detection results at the inlet end under normal and blocked conditions in section A, and Figure 5 The numerical relationship between the detection results at the liquid outlet under normal and blocked conditions in Figure B also shows that the linear relationship between the two figures under normal and blocked conditions tends to be consistent.

[0089] Therefore, the cross-molding pressure data has a certain mathematical relationship with the inlet end, the return end, and the through end, namely: cross-molding pressure value = (pressure value at the inlet end + pressure value at the return end) / 2 - pressure value at the through end;

[0090] Based on this mathematical relationship, we can calculate the corresponding transmembrane pressure by taking the pressure detection values ​​from the inlet end detection signal, the permeate end detection signal, and the return end detection signal.

[0091] Transmembrane pressure is calculated based on the inlet end detection signal, the permeate end detection signal, and the return end detection signal, and the corresponding transmembrane pressure calculation results are as follows:

[0092] Based on the transmembrane pressure calculation formula, the corresponding transmembrane pressure calculation results are obtained by calculating the pressure detection values ​​of the inlet end detection signal, the permeate end detection signal and the return end detection signal.

[0093] The formula for calculating the transmembrane pressure is as follows:

[0094] V = (V1 + V3) / 2 - V2; (7)

[0095] Where V is the calculated transmembrane pressure, V1 is the pressure detection value of the inlet end detection signal, V2 is the pressure detection value of the permeate end detection signal, and V3 is the pressure detection value of the return end detection signal.

[0096] Therefore, it can be seen that, regardless of whether the column is in normal or blocked condition, we can obtain accurate transmembrane pressure calculation results by using the transmembrane pressure calculation formula, based on the pressure detection values ​​of the inlet end detection signal, the permeate end detection signal, and the return end detection signal.

[0097] To better describe the non-immersion cross-molding detection circuit, the following specific embodiments are provided for illustration;

[0098] Example 1: A non-immersion cross-molding detection circuit.

[0099] The non-immersion transmodulus detection circuit consists of four parts. The first part is composed of a high-precision resistor divider network and a first-stage operational amplifier LM358(1). The second part is a second-stage operational amplifier LM358(2) with a negative feedback network composed of HCNR200 / HCNR201. The third part is a third-stage operational amplifier composed of an AD620ANZ amplifier and a precision operational OP1177ARZ chip to convert current into voltage. The fourth part is a fourth-stage operational amplifier composed of an OP27GSZ-REEL.

[0100] The specific workflow is as follows: In the first part, the entire input signal Vin is divided by resistors R1 and R2. Signal acquisition is performed via the positive terminal (pin 3) of U2A (LM358). The signal amplification factor is adjusted by resistor R4 to obtain a suitable value. The calculation formula is: Av = uo / ui = (R4 + R3) / R3 = R4 / R3 + 1. Then, the data is transmitted to the second part through the current-limiting resistor R5. The second part consists of operational amplifier U2B (LM358). C2 can prevent circuit oscillation, filter out glitches, and prevent damage to the LEDs in HCNR200 / HCNR201. However, in high-frequency circuits, C2 will affect the channel gain; a suitable capacitor value can be selected according to the operating frequency. The value of R6 affects the LED luminous intensity, thus playing a role in the channel gain. The third part describes the working principle: the signal flows through the current-limiting resistor R7 to the positive input of AD620ANZ. C4 is used to eliminate low-frequency interference generated by the front-end signal. RG is used to adjust the amplification factor, which can be amplified from 1 to 1000 times. The amplification factor is calculated as gain G = (49.4K / Rg) + 1. OP1177ARZ is used to input a precise reference value for the signal. R9 and R10 are used to adjust the input voltage. After passing through the follower formed by itself, the input and output are equal. The fourth part is the OP27GSZ-REEL operational amplifier. This is a two-stage amplification stage with isolation. The more amplification stages, the more accurate the signal. C6 is used to eliminate low-frequency interference generated by the front-end signal. R13 is used to adjust the amplification factor. R11 is used for current limiting.

[0101] This embodiment uses an analog signal isolation circuit composed of linear optocouplers, which has good linearity, simple circuit calculation, and effectively solves the problem of isolation between analog signals and electrical signals of microcontroller application systems.

[0102] In summary, the non-immersion transmembrane pressure detection circuit of the present invention, by setting up an inlet detection module, a through-flow detection module, a return-flow detection module, and a transmembrane pressure calculation module, and by setting up a non-immersion transmembrane pressure detection circuit in each of the inlet detection module, through-flow detection module, and return-flow detection module, realizes the transmembrane pressure calculation based on the inlet detection signal, through-flow detection signal, and return-flow detection signal output by each circuit to obtain the corresponding transmembrane pressure calculation result; and by setting up a high-precision resistor voltage divider network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optocoupler, a third-stage operational amplifier circuit, and a fourth-stage operational amplifier circuit in the non-immersion transmembrane pressure detection circuit, and a four-stage amplification and analog signal isolation circuit, realizes the conversion of the detected current signal into an electrical signal by utilizing the piezoelectric effect of operational amplification, and provides an anti-interference signal electrical output through the piezoelectric isolation chip. The present invention not only has good linearity and simple circuit calculation, but also effectively solves the problem of electrical signal isolation between analog signals and microcontroller application systems. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0103] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A non-immersion cross-molding inspection system, characterized in that, The system includes: Inlet detection module, permeate detection module, return detection module, and transmembrane pressure calculation module; The inlet detection module, the through-end detection module, and the return-end detection module are each equipped with a non-immersion cross-molding detection circuit. The liquid inlet detection module is used to output a corresponding liquid inlet detection signal based on the input signal of the corresponding liquid inlet. The transmission end detection module is used to output a corresponding transmission end detection signal based on the input signal of the corresponding transmission end; The return end detection module is used to output a corresponding return end detection signal based on the input signal of the corresponding return end; The transmembrane pressure calculation module is connected to the liquid inlet detection module, the permeate detection module and the reflux detection module. It is used to perform transmembrane pressure calculation based on the liquid inlet detection signal, the permeate detection signal and the reflux detection signal to obtain the corresponding transmembrane pressure calculation result. Furthermore, each non-immersion transmodulation detection circuit includes: a high-precision resistor divider network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optocoupler, a third-stage operational amplifier circuit, and a fourth-stage operational amplifier circuit. Each non-immersion transmodulation detection circuit consists of a first circuit module composed of a high-precision resistor voltage divider network and a first-stage operational amplifier circuit; a second circuit module composed of a negative feedback network formed by a second-stage operational amplifier circuit and a linear optocoupler; and a third circuit module and a fourth circuit module composed of a third-stage operational amplifier circuit and a fourth-stage operational amplifier circuit, respectively. The first circuit module, the second circuit module, the third circuit module, and the fourth circuit module are connected in series in sequence. The corresponding input signal is divided by a high-precision resistor voltage divider network in the first circuit module and then amplified by a first-stage operational amplifier circuit to obtain a first signal. The first signal is input to the second circuit module, where it is amplified by a second-stage operational amplifier circuit and optically isolated by a linear optocoupler to obtain a second signal and output a corresponding output signal. The output signal from the second circuit module is amplified by a third circuit module to obtain a third signal and then amplified by a third-stage operational amplifier circuit to obtain a fourth and a fifth signal. The fourth signal is input to the fourth circuit module, amplified by a fourth-stage operational amplifier circuit, and outputs a corresponding detection signal. Among them, after isolation, the signal values ​​of the first signal, the second signal, and the third signal are equal; the signal value of the corresponding detection signal is calculated based on the signal value of the fourth signal which is related to the signal value of the third signal.

2. The non-immersion cross-molding inspection system according to claim 1, characterized in that, The first circuit module includes: a first resistor, a second resistor, a first-stage operational amplifier, a third resistor, a fourth resistor, a fifth resistor, and a first capacitor; In this circuit, one end of the first resistor is connected to the signal input terminal for inputting the corresponding input signal, and the other end is connected to one end of the second resistor and the positive input pin of the first-stage operational amplifier; the other end of the second resistor is grounded; one end of the third resistor is connected to the inverting input pin of the first-stage operational amplifier and one end of the fourth resistor, and the other end is grounded; the other end of the fourth resistor is connected to the output pin of the first-stage operational amplifier and one end of the fifth resistor; the other end of the fifth resistor is connected to the second circuit module; one end of the first capacitor is connected to the power supply and the positive power supply pin of the first-stage operational amplifier, and the other end is grounded. The first resistor and the second resistor form a high-precision resistor voltage divider network, which is used to divide the input signal to obtain the acquisition signal input to the first-stage operational amplifier; the first-stage operational amplifier, the third resistor, the fourth resistor, the fifth resistor and the first capacitor form a first-stage operational amplifier circuit, which is used to perform first-stage amplification through the first-stage amplifier, and the amplification factor is adjusted by the fourth resistor. The amplified signal is then current-limited by the fifth resistor to obtain the first signal, which is then transmitted to the second circuit module. Furthermore, the signal value of the acquired signal satisfies a first numerical relationship with the input signal value, the first resistance value, and the second resistance value; and the signal value of the first signal satisfies a second numerical relationship with the signal value of the acquired signal, the third resistance value, and the fourth resistance value.

3. The non-immersion cross-molding inspection system according to claim 2, characterized in that, The first numerical relationship includes: Vin1 = Vin × (R1 × R2 / R1 + R2); Wherein, Vin1 is the signal value of the acquired signal, Vin is the input signal value, R1 is the first resistance value, and R2 is the second resistance value; The second numerical relationship includes: Out1 = (R4 / R3+1) × Vin1; Where Out1 is the signal value of the first signal, Vin1 is the signal value of the acquired signal, R3 is the third resistance value, and R4 is the fourth resistance value.

4. The non-immersion cross-molding inspection system according to claim 3, characterized in that, The second circuit module includes: a linear optocoupler, a second-stage operational amplifier, a sixth resistor, and a second capacitor for placing the circuit to generate oscillations; The second-stage operational amplifier has its positive input pin connected to ground, its negative input pin connected to one end of the second capacitor, and its output pin connected to the other end of the second capacitor and one end of the sixth resistor. The linear optocoupler includes a light-emitting diode (LED), a first photodiode, and a second LED. The anode pin of the LED is connected to the power supply, and the cathode pin is connected to the other end of the sixth resistor. The anode pin of the first photodiode is grounded, and the cathode pin is connected to the other end of the fifth resistor. The anode pin of the second photodiode is grounded, and the cathode pin is connected to the third circuit module. The second-stage operational amplifier, the sixth resistor, and the second capacitor constitute a second-stage operational amplifier circuit for negative feedback amplification, which is used to amplify the input first signal in the second stage to obtain a second signal, and input it to the linear optocoupler; the linear optocoupler performs optical isolation based on the input first signal and the second signal and outputs the corresponding output signal.

5. The non-immersion cross-molding inspection system according to claim 1, characterized in that, The third-stage operational amplifier circuit of the signal amplification module includes: a high-precision operational amplifier, a seventh resistor, a precision operational amplifier chip, an eighth resistor, a ninth resistor, a tenth resistor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, and a first sliding rheostat; In this configuration, one end of the seventh resistor is connected to the cathode pin of the second light-emitting diode of the linear optocoupler, and the other end is connected to one end of the fourth capacitor and a negative input pin of the high-precision operational amplifier. The other negative input pin of the high-precision operational amplifier is connected to its own positive input pin via a first sliding rheostat. Its other positive input pin is grounded. Its output pin is connected to the other end of the fourth capacitor and one end of the eighth resistor. Its positive power supply pin is connected to the power supply voltage terminal, and its negative power supply pin is connected to the sixth capacitor (one end of which is grounded) and the negative voltage power supply terminal. Its other negative power supply pin is connected to the output pin of the precision operational amplifier chip and a negative input pin. The other end of the eighth resistor is connected to one end of the fifth capacitor and the fourth circuit module. The other end of the fifth capacitor is grounded. The positive input pin of the precision operational amplifier chip is connected to the connection terminals of the ninth and tenth resistors. The other end of the ninth resistor is connected to the power supply voltage terminal, and the other end of the tenth resistor is connected to the negative voltage power supply. The output signal from the second circuit module is current-limited by the seventh resistor and then input to the high-precision operational amplifier. The amplification factor is adjusted by the first sliding rheostat and the low-frequency interference generated by the front-end signal is eliminated by the fourth capacitor to obtain the fourth signal. The fifth signal is obtained by the precision operational amplifier chip based on the input voltage adjusted by the ninth and tenth resistors to input a precise signal reference value. Furthermore, the signal value of the fifth signal satisfies the third numerical relationship with the ninth and tenth resistance values; the signal value of the fourth signal satisfies the fourth numerical relationship with the resistance adjustment value of the first sliding rheostat and the signal value of the third signal.

6. The non-immersion cross-molding inspection system according to claim 5, characterized in that, The third numerical relationship includes: Out5 = VDD × (R9 × R10 / R9 + R10); Where Out5 is the signal value of the fifth signal, VDD is the power supply voltage value, R92 is the ninth resistor value, and R10 is the tenth resistor value; The fourth numerical relationship includes: Out4=((49.4K / Rg)+1)×Out3; Where Out4 is the signal value of the fourth signal, Out5 is the signal value of the fifth signal, and Rg is the adjustment resistance value of the first sliding rheostat.

7. The non-immersion cross-molding inspection system according to claim 6, characterized in that, The fourth operational amplifier circuit of the fourth circuit module includes: The eleventh resistor, the fourth operational amplifier, the sixth capacitor, the second variable resistor, and the twelfth resistor; In this configuration, the positive input pin of the fourth-stage operational amplifier is connected to the eighth resistor, and its negative input pin is connected to one end of the eleventh resistor, one end of the second sliding rheostat, and one end of the sixth capacitor. Its output pin is connected to one end of the twelfth resistor. The other end of the eleventh resistor is grounded. The other end of the second sliding rheostat is connected to the other end of the sixth capacitor and one end of the twelfth resistor. The other end of the twelfth resistor outputs the corresponding detection signal. The fourth input signal is biased and amplified by the fourth operational amplifier, while the amplification factor is adjusted by the second sliding rheostat. The low-frequency interference generated by the front-end signal is eliminated by the sixth capacitor. The amplified signal is then current-limited by the twelfth resistor to obtain the detection signal and output. Furthermore, the signal value of the detection signal satisfies the fifth numerical relationship with the signal value of the fourth signal, the eleventh resistor, and the adjustment resistance value of the second sliding rheostat.

8. The non-immersion cross-molding inspection system according to claim 7, characterized in that, The fifth numerical relationship includes: Out6=((R13 / R11+1)×Out4); Where Out6 is the signal value of the corresponding detection signal, Out4 is the signal value of the fourth signal, R11 is the eleventh resistance value, and R13 is the adjustment resistance value of the second sliding rheostat.

9. The non-immersion cross-molding inspection system according to claim 1, characterized in that, Transmembrane pressure is calculated based on the inlet end detection signal, the permeate end detection signal, and the return end detection signal, and the corresponding transmembrane pressure calculation results are as follows: Based on the transmembrane pressure calculation formula, the corresponding transmembrane pressure calculation results are obtained by calculating the pressure detection values ​​of the inlet end detection signal, the permeate end detection signal and the return end detection signal. The formula for calculating the transmembrane pressure is as follows: V = (V1 + V3) / 2 - V2; In this context, V represents the transmembrane pressure calculation result, V1 represents the pressure detection value of the inlet end detection signal, V2 represents the pressure detection value of the permeate end detection signal, and V3 represents the pressure detection value of the reflux end detection signal.

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