Outdoor working type gaseous nitrous acid analyzer

Abstract

The utility model relates to a gas monitoring technology, and particularly provides an outdoor working type gaseous nitrous acid analyzer which comprises a sampling unit, a separation unit and an analysis unit which are connected in sequence, according to the sampling unit, an inner box is arranged in an outer box, and heat insulation layers are arranged on the outer walls or the inner walls of the outer box and the inner box respectively; the inlet and the first outlet are respectively formed in the outer box; the fans are respectively arranged in the outer box and the inner box, and the heater is arranged between the inner box and the outer box; the first spiral absorption pipe, the second spiral absorption pipe and the heat conduction piece are arranged in the inner box, and the first spiral absorption pipe and the second spiral absorption pipe are arranged around the heat conduction piece or integrally cast with the heat conduction piece; the TEC and the radiator are arranged between the inner box and the outer box, and the TEC is connected with the heat conduction piece; and the first gas-liquid separator and the second gas-liquid separator are arranged in the inner box. The temperature control device has the advantages of stable temperature control and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to gas monitoring technology, especially relate to outdoor working formula gaseous nitrous acid analyzer. BACKGROUND

[0002] As a commonly used instrument, the gaseous nitrous acid (HONO) measuring instrument based on long optical path differential absorption spectroscopy technology (LOPAP) integrated wet chemical method is mainly affected by the interference in the atmosphere, including NO2, NO2+SO2, NO2+phenol and PAN, etc. Most of the current mainstream LOPAP commercial instruments use external sampling units to realize in-situ sampling absorption, and use double-channel sampling structure in series to eliminate related interference signals. Since the sampling unit is placed outdoors, how to realize stable and reliable temperature control of the absorption module in the outdoor environment with large temperature changes becomes an important technical difficulty.

[0003] At present, the HONO external sampling unit basically uses a circulating water bath to control the temperature of the absorption module, and the entire absorption tube adopts a double-layer glass sleeve structure, the inner layer is a combination structure of a double-channel glass spiral absorption tube and two gas-liquid separators, and the outer layer is controlled by circulating water bath. The disadvantages of this scheme are:

[0004] 1. The water bath method is not suitable for application scenarios below 0 DEG C and above 40 DEG C.

[0005] 2. When the ambient temperature fluctuates greatly in a short time, the temperature control precision is poor and the temperature control uniformity is poor.

[0006] 3. In the case of rapid change of ambient temperature, the absorption module is slow in temperature control.

[0007] 4. The integrated structure design of the glass spiral absorption tube and the gas-liquid separator is large in size.

[0008] 5. There is a risk of liquid leakage and poor reliability.

[0009] 6. The operation workload is large, and it is necessary to check whether the water in the circulating water bath is depleted in time. After long-term use, the spiral absorption tube will be dirty, and even the pipeline will be blocked, which needs to be cleaned regularly. Utility model content

[0010] In order to solve the above technical problems, the utility model provides an outdoor working formula gaseous nitrous acid analyzer.

[0011] The utility model aims to realize the following technical scheme:

[0012] An outdoor working formula gaseous nitrous acid analyzer, comprising a sampling unit, a separation unit and an analysis unit connected in sequence; the sampling unit comprises:

[0013] The outer box and the inner box are provided with heat insulation layers on the outer wall or the inner wall of the outer box and the inner box respectively; and an inlet and a first outlet are provided on the outer box respectively;

[0014] A fan and a heater are provided in the outer box and the inner box respectively, and the heater is provided between the inner box and the outer box;

[0015] A first spiral absorption tube, a second spiral absorption tube and a heat conducting member are provided in the inner box, the first spiral absorption tube and the second spiral absorption tube are provided around the heat conducting member, or the first spiral absorption tube and the second spiral absorption tube are integrally cast with the heat conducting member;

[0016] A TEC and a heat sink are provided between the inner box and the outer box, and the TEC is connected with the heat conducting member;

[0017] A first gas-liquid separator and a second gas-liquid separator, the inlet of the first gas-liquid separator is connected with the outlet of the first spiral absorption tube, the gas outlet is connected with the inlet of the second spiral absorption tube, and the liquid outlet is communicated with the analysis unit, the inlet of the second gas-liquid separator is connected with the outlet of the second spiral absorption tube, the gas outlet is connected with an exhaust pipe, and the liquid outlet is connected with the analysis unit; absorption liquid is connected with the inlets of the first spiral absorption tube and the second spiral absorption tube through pipelines penetrating the inner box and the outer box, and a sample is connected with the inlet of the first spiral absorption tube through a pipeline.

[0018] Compared with the prior art, the application has the beneficial effects that:

[0019] 1. The inner and outer boxes are used for temperature control, the outer box is used for temperature feedback adjustment, and the inner box is used for self-adaptive PID temperature control, so that the outdoor sampling unit can be used in an external environment temperature of-40-70 DEG C, and can be controlled at a target value of ± 0.5 DEG C (the target value can be set to 5-25 DEG C) in an extreme environment temperature;

[0020] The application adopts a metal bath combined with a sampling unit for temperature control, a double-layer heat preservation bubble cotton nested structure of the inner and outer boxes is used in structure, and an efficient circulating flow air duct is designed; when the fluctuation range of the environmental temperature reaches 5 DEG C within 5 min, the sampling control precision can be kept at a target value of ± 0.5 DEG C, the temperature difference at the gas-liquid separator and the spiral absorption tube is less than or equal to 0.5 DEG C, and the absorption efficiency is kept above 99.5%;

[0021] 2. The spiral absorption tube and the gas-liquid separator are designed in a split mode, the volume is reduced, and temperature control and maintenance are facilitated;

[0022] 3. Water bath is not used, and liquid leakage does not occur;

[0023] 4. The spiral absorption tube is made of corrosion-resistant metal material, which eliminates the need for frequent cleaning and disassembly, making maintenance easy. Attached Figure Description

[0024] The disclosure of this utility model will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are merely illustrative of the technical solutions of this utility model and are not intended to limit the scope of protection of this utility model. In the drawings:

[0025] Figure 1 This is a schematic diagram of the sampling unit according to the present invention;

[0026] Figure 2 This is a schematic diagram of the air duct inside the sampling unit of this utility model;

[0027] Figure 3 This is based on the temperature change diagram in Embodiment 2 of this utility model;

[0028] Figure 4 This is a schematic diagram of temperature change according to Embodiment 3 of this utility model;

[0029] Figure 5 This is a temperature difference diagram based on Embodiment 3 of this utility model.

[0030] In the attached diagram, 1-first spiral absorption tube, 2-first temperature sensor, 3-heat conductor, 4-second spiral absorption tube, 5-first fan, 6-heat sink, 7-TEC, 8-first mixing tee connector, 9-second temperature sensor, 10-third temperature sensor, 11-first gas-liquid separator, 12-heater, 13-second fan, 14-second mixing tee connector, 15-second gas-liquid separator, 16-third fan, 17-first outlet, 18-inlet, 19-second outlet, 20-third outlet, 21-outer casing, 22-inner casing, 31-first gas pipe, 32-first absorbent liquid pipe, 33-first liquid pipe, 34-second absorbent liquid pipe, 35-second gas pipe, 36-second liquid pipe. Detailed Implementation

[0031] Figures 1-5 The following description illustrates optional embodiments of the present invention to teach those skilled in the art how to implement and reproduce it. For the purpose of teaching the technical solutions of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art should understand that variations or substitutions derived from these embodiments will be within the scope of the present invention. Those skilled in the art should understand that the following features can be combined in various ways to form multiple variations of the present invention. Therefore, the present invention is not limited to the following optional embodiments, but is defined only by the claims and their equivalents.

[0032] The inner layer of the outer box 21 refers to the interlayer between the outer box 21 and the inner box 22.

[0033] Example 1

[0034] This embodiment of an outdoor working gaseous nitrous acid analyzer includes a connected sampling unit and an analysis unit.

[0035] like Figure 1 As shown, the sampling unit includes:

[0036] The inner box 22 is located inside the outer box 21, and the heat insulation layer is respectively located on the outer wall or inner wall of the outer box 21 and the inner box 22; the inlet 18 and the first outlet 17 are respectively located on the outer box 21.

[0037] Fans are installed in the outer casing 21 and the inner casing 22 respectively to drive the gas flow within the outer casing 21 and the inner casing 22. A heater 12 is installed between the inner casing 22 and the outer casing 21.

[0038] The first spiral absorption tube 1, the second spiral absorption tube 4, and the heat-conducting component 3 are arranged inside the inner box 22. The first spiral absorption tube 1 and the second spiral absorption tube 4 are arranged around the heat-conducting component 3, or the first spiral absorption tube 1 and the second spiral absorption tube 4 are integrally cast with the heat-conducting component 3 to improve the heat conduction efficiency.

[0039] The TEC7 and the heat sink are disposed between the inner casing 22 and the outer casing 21, and the TEC7 is connected to the heat-conducting component 3.

[0040] The inlet of the first gas-liquid separator 11 is connected to the outlet of the first spiral absorption tube 1, the gas outlet is connected to the inlet of the second spiral absorption tube 4, and the liquid outlet is connected to the analytical unit. The inlet of the second gas-liquid separator 15 is connected to the outlet of the second spiral absorption tube 4, the gas outlet is connected to the exhaust pipe, and the liquid outlet is connected to the analytical unit. The absorption liquid is connected to the inlets of the first spiral absorption tube 1 and the second spiral absorption tube 4 through pipes passing through the inner box 22 and the outer box 21, respectively. The sample is connected to the inlet of the first spiral absorption tube 1 through a pipe.

[0041] To improve temperature control efficiency, a second outlet 19 and a third outlet 20 are further disposed on the outer casing 21. The inlet 18, the first outlet 17, the second outlet 19, and the third outlet 20 are respectively disposed at the corners of the outer casing 21, forming an air duct under the drive of the third fan 16. Figure 2 As shown, the arrows represent the direction of airflow.

[0042] The inlet of the first spiral absorption tube 1 is connected to the sample and the absorption liquid through a three-way connector, and the inlet of the second spiral absorption tube 4 is connected to the gas outlet of the first gas-liquid separator 11 and the absorption liquid through the same three-way connector.

[0043] Temperature sensors are respectively installed in the inner box 22 and the outer box 21, and the output temperature is transmitted to the PID temperature control module.

[0044] The PID temperature control module adjusts the operating parameters of the TEC7 and the heater 12 according to the received temperature. This temperature control module is a prior art in the field.

[0045] Example 2

[0046] Application example of an outdoor working gaseous nitrite analyzer according to Embodiment 1 of this utility model.

[0047] In this application example, the sampling unit is located outdoors, with an outdoor ambient temperature of -40 to 70°C, while the analysis unit is located in an air-conditioned room.

[0048] like Figure 1 As shown, the insulation layers surrounding the outer box 21 and inner box 22 are made of insulating foam, each 30cm thick. The first spiral absorption tube 1 and the second spiral absorption tube 4 have inner diameters of 2.5mm and outer diameters of 3.5mm, respectively, and are both wound 5 times around the heat-conducting component 3 (an aluminum rod). The first temperature sensor 2 is a thermocouple, inserted into the heat-conducting component 3. The second temperature sensor 9 is located inside the outer box 21, and the third temperature sensor 10 is located inside the inner box 22. The heater 12 uses a heating element with a power of 70W.

[0049] The TEC7 has a power rating of 300W. The heatsink consists of a heatsink 6 and a first fan 5, which has a power rating of 6W and dimensions of 50×50×38mm.

[0050] The second fan 13 is located inside the inner casing 22, with a power of 5W and dimensions of 50×50×20mm. The third fan 16 is located inside the outer casing 21, with a power of 8W and dimensions of 60×60×25mm.

[0051] The ambient sample gas enters the first mixing tee connector 8 through the first gas pipe 31, and the absorbent enters the first mixing tee connector 8 through the first absorbent pipe 32. The sample gas and absorbent mix at the first mixing tee connector 8, and then enter the first spiral absorption tube 1 for complete reaction. The liquid separated by the first gas-liquid separator 11 is discharged through the first liquid pipe 33, and the gas enters the second mixing tee connector 14. The absorbent enters the second mixing tee connector 14 through the second absorbent pipe 34, and the gas and absorbent mix in the second mixing tee connector 14, then enter the second spiral absorption tube 4 for complete reaction. The liquid separated by the second gas-liquid separator 15 is discharged through the second liquid pipe 36, and the gas is discharged through the second gas pipe 35. The solutions discharged from the first liquid pipe 33 and the second liquid pipe 36 are both transported to the analysis unit for collection and detection to obtain the HONO concentration in the ambient sample gas.

[0052] The target temperature of the first spiral absorption tube 1 and the second spiral absorption tube 4 is set to 10℃. At various temperatures, such as -20℃, 0℃, 20℃, 40℃, and 70℃, the output value of the first temperature sensor 2 is recorded. The data results are as follows: Figure 3 As shown, under an ambient temperature of -40 to 70°C, the absorption module (i.e., the collective name of the heat-conducting component 3, the first spiral absorption tube 1, and the second spiral absorption tube 4) can be stably controlled between 9.9 and 10.1°C, with a temperature control accuracy of ±0.1°C.

[0053] Example 3

[0054] The application example of the outdoor working gaseous nitrous acid analyzer according to Embodiment 1 of this utility model differs from Embodiment 2 in that:

[0055] The sampling unit is placed in an aging chamber, and the analysis unit is located in an air-conditioned room. Zero gas is introduced through the first gas tube 31, HONO standard solution is connected to the first absorbent tube 32, and absorbent solution is connected to the second absorbent tube 34. The zero gas and standard solution are mixed at the first mixing tee connector 8.

[0056] The target temperature of the absorption module was set to 15℃. The temperature of the aging chamber was adjusted to fluctuate within the range of 25~32℃ for 5 minutes, and the change in the target temperature of the absorption module during this period was observed. The data results are as follows: Figure 4 As shown, when the ambient temperature fluctuates by 5°C within 5 minutes, the temperature of the absorption module can be stably controlled between 14.9 and 15.1°C, and the control accuracy can be maintained at ±0.1°C.

[0057] The target temperature of the absorption module was set to 15℃. The temperature of the aging chamber was adjusted to fluctuate within the range of 25~32℃ for 5 minutes. Simultaneously, the real-time temperatures at the first spiral absorption tube 1, the second spiral absorption tube 4, the first gas-liquid separator 11, and the second gas-liquid separator 15 were measured, and the maximum temperature difference was observed. The data results are as follows: Figure 5 As shown, when the ambient temperature fluctuates by 5℃ within 5 minutes, the temperature at both the spiral absorption tube and the gas-liquid separator can be controlled at 14.8~15.2℃, with a maximum temperature difference within 0.3℃, and the temperature uniformity of the inner chamber 22 is good.

Claims

1. An outdoor working gaseous nitrous acid analyzer, comprising a sampling unit, a separation unit, and an analysis unit connected in sequence; characterized in that, The sampling unit includes: An outer casing and an inner casing, wherein the inner casing is disposed inside the outer casing, and heat insulation layers are respectively disposed on the outer wall or inner wall of the outer casing and the inner casing; an inlet and a first outlet are respectively disposed on the outer casing; A fan and a heater, wherein the fan is respectively disposed in the outer casing and the inner casing, and the heater is disposed between the inner casing and the outer casing; The first spiral absorption tube, the second spiral absorption tube, and the heat-conducting component are disposed inside the inner box. The first spiral absorption tube and the second spiral absorption tube are both arranged around the heat-conducting component, or the first spiral absorption tube and the second spiral absorption tube are both integrally cast with the heat-conducting component. A heat exchanger and a radiator are disposed between the inner and outer casings, and the heat exchanger is connected to the heat-conducting component. A first gas-liquid separator and a second gas-liquid separator are connected. The inlet of the first gas-liquid separator is connected to the outlet of the first spiral absorption tube, the gas outlet is connected to the inlet of the second spiral absorption tube, and the liquid outlet is connected to the analysis unit. The inlet of the second gas-liquid separator is connected to the outlet of the second spiral absorption tube, the gas outlet is connected to the exhaust pipe, and the liquid outlet is connected to the analysis unit. The absorption liquid is connected to the inlets of the first and second spiral absorption tubes through pipes passing through the inner and outer boxes, respectively. The sample is connected to the inlet of the first spiral absorption tube through a pipe.

2. The gaseous nitrous acid analyzer according to claim 1, characterized in that, The second outlet is located on the outer casing, and the inlet, the first outlet, and the second outlet are respectively located at the corners of the outer casing.

3. The gaseous nitrous acid analyzer according to claim 1, characterized in that, The analyzer also includes: The three-way connector connects the inlet of the first spiral absorption tube to the sample and the absorption liquid, and the inlet of the second spiral absorption tube connects the gas outlet of the first gas-liquid separator and the absorption liquid through the three-way connector.

4. The gaseous nitrous acid analyzer according to claim 1, characterized in that, The radiator includes heat dissipation fins and a separate fan.

5. The gaseous nitrous acid analyzer according to claim 1, characterized in that, The analyzer also includes: Temperature sensors are respectively installed inside the inner box and the outer box, and the output temperature is transmitted to the PID temperature control module. A PID temperature control module adjusts the operating parameters of the TEC and the heater based on the received temperature.

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