Power plant urea hydrolysate sampling device and method

Abstract

The embodiment of the invention provides a urea hydrolysate sampling device for a power plant. The urea hydrolysate sampling device comprises a sampling bottle; a weighing device; the quick-insertion sampling tube is inserted into the sampling bottle; one end of the sampling hose is communicated with the inlet end of the quick-insertion sampling pipe, and the other end of the sampling hose is communicated with a power plant urea hydrolyzer; the breather valve is arranged at the opening of the sampling bottle and is used for adjusting the pressure in the sampling bottle; during sampling, the outlet end of the quick-insertion sampling tube extends into the sampling bottle by a preset depth below the liquid level of the absorption liquid, so that the urea hydrolysate is absorbed by utilizing the absorption liquid and the quick-insertion sampling tube is cooled. The sampling device disclosed by the invention is a sampling device with an internal cooling function, namely, the quick-insertion sampling tube is cooled by utilizing absorption liquid. Besides, the quick-insertion sampling tube extends below the liquid level of the absorption liquid, so that the quick-insertion sampling tube can be cooled by utilizing the absorption liquid, the danger of scalding an operator at high temperature is avoided, and the sampling solution can be effectively inhibited from flash evaporation.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the technical field of urea hydrolyzate sampling, and specifically relate to a urea hydrolyzate sampling device and method for a power plant. Background Art

[0002] With the commissioning of the urea hydrolysis ammonia production unit, many problems have emerged, such as stress corrosion cracking and damage to the hydrolyzer heat exchange tube, which has caused the denitrification system to shut down. The low concentration of the main components of the urea concentrate in the hydrolyzer leads to insufficient product gas output, and sodium chloride crystals appear on the hydrolyzer heat exchange tube, affecting the heat exchange efficiency of the hydrolyzer and the normal operation of the denitrification system. What is more serious is that a large amount of chloride ions will cause intergranular corrosion, stress corrosion cracking and uniform corrosion of the 316L stainless steel hydrolyzer; product gas pipeline corrosion and cracking, etc. According to research and analysis, the corrosion and cracking and surface crystallization of the heat exchange tube of the urea hydrolysis ammonia production unit are mainly related to the excessive chloride in the incoming urea and the sewage control method of the urea hydrolyzer.

[0003] At present, all power plants have gradually paid attention to the supervision of impurity content in urea hydrolyzate. On-site investigation found that the urea hydrolyzate put into operation in the early stage did not have a sampling point. Most of the samples were taken from the sewage outlet temporarily. The sample water temperature was greater than 100°C and had a strong pungent odor. There was a risk of high temperature burns and a risk to human health during sampling. In addition, flash gas would also change the chloride ion concentration in the sample. Therefore, setting reasonable sampling points and sampling devices is also one of the problems that need to be solved urgently. Characteristics of urea hydrolyzate: high temperature, pungent odor, containing urea, ammonia, carbon dioxide and water, high urea concentration and easy to crystallize after cooling.

[0004] In order to prevent personal injury and sample volatilization loss during the sampling process, an external, simple and convenient urea hydrolyzate sampling device is urgently needed. Summary of the invention

[0005] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a device and method for sampling urea hydrolyzate in a power plant.

[0006] A first aspect of an embodiment of the present disclosure provides a urea hydrolyzate sampling device for a power plant, comprising: a sampling bottle;

[0007] A weighing device, which is arranged on the sampling bottle and is used to weigh the mass of the absorption liquid in the sampling bottle and, after sampling, to weigh the mass of the mixed liquid in the sampling bottle, wherein the mixed liquid includes the absorption liquid and the urea hydrolyzate;

[0008] A quick-insert sampling tube, which is inserted into the sampling bottle; the quick-insert sampling tube is a hard tube;

[0009] A sampling hose, one end of which is connected to the inlet end of the quick-plug sampling tube, and the other end of which is used to be connected to the urea hydrolyzer of the power plant;

[0010] A breathing valve, which is arranged at the mouth of the sampling bottle and is used to adjust the pressure in the sampling bottle;

[0011] During sampling, the outlet end of the quick-insert sampling tube extends into the sampling bottle to a preset depth below the surface of the absorption liquid, so that the absorption liquid can absorb the urea hydrolyzate and cool the quick-insert sampling tube.

[0012] Furthermore, it also includes: a primary valve, which is arranged on the sampling hose and is used to adjust the flow rate of the urea hydrolyzate flowing into the sampling bottle.

[0013] Furthermore, it also includes: a secondary valve, which is arranged on the sampling hose and arranged downstream of the primary valve to adjust the flow rate of the urea hydrolyzate flowing into the sampling bottle.

[0014] Optionally, the quick-insert sampling tube includes a sampling hard tube body and a quick-insert structure arranged at the inlet end of the sampling hard tube body, and the quick-insert structure is used for quick-insert connection with the sampling hose.

[0015] Optionally, the sampling hose includes a sampling hose body and a buckle structure arranged on the sampling hose body, and the buckle structure is used to buckle the sampling hose body to the quick-insert structure.

[0016] Optionally, the material of the sampling hose includes polypropylene or polytetrafluoroethylene.

[0017] Furthermore, it also includes: a cooling device, which is arranged on the periphery of the sampling bottle and is used to cool the sampling bottle.

[0018] Optionally, the sampling bottle includes a bottle body and a bottle cap threadedly connected to a bottle mouth of the bottle body.

[0019] A second aspect of the embodiments of the present disclosure provides a method for sampling urea hydrolyzate in a power plant. The method is implemented according to the sampling device described above, and includes:

[0020] A preset volume of absorption liquid is placed in the sampling bottle, and the outlet end of the quick-insert sampling tube is inserted into a preset depth below the surface of the absorption liquid;

[0021] Opening the primary valve and the secondary valve in sequence at preset intervals to allow the urea hydrolyzate in the urea hydrolyzer of the power plant to flow into the sampling bottle;

[0022] The breathing valve is used to adjust the pressure in the sampling bottle.

[0023] Furthermore, it also includes:

[0024] Weigh the weight of the sampling bottle and the absorption liquid before sampling m 1 ;

[0025] Weigh the weight of the sampling bottle and the mixed liquid after sampling m 2 , wherein the mixed liquid includes an absorption liquid and a urea hydrolyzate;

[0026] According to weight m 1 and weight m 2 Calculate the weight of urea hydrolyzate in the sampling bottle (m 2 -m 1 ) g, and determine the volume V mL of the urea hydrolyzate taken according to the density of the urea hydrolyzate;

[0027] The mixed solution in the sampling bottle is transferred to a volumetric flask and fixed to a preset volume, and the dilution multiple of the urea hydrolyzate is determined according to the volume VmL of the urea hydrolyzate and the preset volume of the volumetric flask;

[0028] The content of impurity ions in the urea hydrolyzate is analyzed according to the dilution multiple of the urea hydrolyzate.

[0029] The beneficial effects of the embodiments of the present disclosure include:

[0030] The sampling device of the present invention is a sampling device with an internal cooling function, that is, the quick-insert sampling tube is cooled by the absorption liquid. The beneficial effects of the sampling device of the present invention include: extending the quick-insert sampling tube below the liquid surface of the absorption liquid is beneficial to the absorption of urea hydrolyzate by the absorption liquid. In addition, by extending the quick-insert sampling tube below the liquid surface of the absorption liquid, the absorption liquid can be used to cool the quick-insert sampling tube to avoid the risk of high-temperature burns to the operator, and the flash evaporation of the sampling solution can also be effectively suppressed. Furthermore, by providing a breathing valve at the bottle mouth of the sampling bottle to adjust the pressure in the sampling bottle, the leakage or splashing of the sample caused by pressure changes can be effectively prevented, thereby improving the safety of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a urea hydrolyzate sampling device for a power plant according to an embodiment of the present disclosure;

[0032] Figure 2 It is a schematic diagram of the structure of a sampling bottle according to an embodiment of the present disclosure;

[0033] Figure 3 The structure diagram of the quick-insert sampling tube, bottle cap and breathing valve of one embodiment of the present disclosure is shown; wherein the connection relationship between the quick-insert sampling tube, bottle cap and breathing valve is shown;

[0034] Figure 4 This is a schematic diagram of the structure of a sampling hose and a urea hydrolyzer of a power plant according to an embodiment of the present disclosure; wherein the connection relationship between the sampling hose and the urea hydrolyzer of the power plant is schematically shown;

[0035] Figure 5 The present invention is a schematic flow chart of a method for sampling urea hydrolyzate in a power plant according to an embodiment of the present invention.

[0036] In the figure, 10, urea hydrolyzate sampling device; 1, sampling bottle; 2, quick-insert sampling tube; 3, sampling hose; 4, breathing valve; 5, primary valve; 6, secondary valve; 7, cooling device; 11, bottle body; 12, bottle cap; 21, sampling hard tube body; 22, quick-insert structure; 30, urea hydrolyzer of power plant; 31, urea hydrolyzate sampling tube; 32, first sewage valve. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] The following is a further detailed description of the implementation methods of the present application in conjunction with the accompanying drawings and examples. The detailed descriptions and drawings of the following examples are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments. In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "multiple" is more than two; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inside", "outside", etc. is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the error tolerance range. "Parallel" is not parallel in the strict sense, but within the error tolerance range.

[0039] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0040] like Figure 1-4As shown, a sampling device 10 for urea hydrolyzate in a power plant, the sampling device comprises a sampling bottle 1, a weighing device, a quick-insert sampling tube 2, a sampling hose 3 and a breathing valve 4. The quick-insert sampling tube is inserted into the sampling bottle, one end of the sampling hose is connected to the inlet end of the quick-insert sampling tube, and the other end of the sampling hose is used to communicate with the urea hydrolyzer 30 of the power plant. The breathing valve is arranged at the mouth of the sampling bottle to adjust the pressure in the sampling bottle. The quick-insert sampling tube is a hard tube. The weighing device is arranged on the sampling bottle to weigh the mass of the absorption liquid in the sampling bottle, and after sampling, to weigh the mass of the mixed liquid in the sampling bottle, the mixed liquid comprising the absorption liquid and the urea hydrolyzate.

[0041] When sampling, the outlet end of the quick-insert sampling tube is inserted into the sampling bottle to a preset depth below the surface of the absorption liquid, so that the absorption liquid can absorb the urea hydrolyzate and cool the quick-insert sampling tube.

[0042] The sampling device of the present invention is a sampling device with an internal cooling function, that is, the quick-insert sampling tube is cooled by the absorption liquid. The beneficial effects of the sampling device of the present invention include: extending the quick-insert sampling tube below the liquid surface of the absorption liquid is beneficial to the absorption of urea hydrolyzate by the absorption liquid. In addition, by extending the quick-insert sampling tube below the liquid surface of the absorption liquid, the absorption liquid can be used to cool the quick-insert sampling tube to avoid the risk of high-temperature burns to the operator, and the flash evaporation of the sampling solution can also be effectively suppressed. Furthermore, by providing a breathing valve at the bottle mouth of the sampling bottle to adjust the pressure in the sampling bottle, the leakage or splashing of the sample caused by pressure changes can be effectively prevented, thereby improving the safety of the operation.

[0043] In some embodiments, the absorption liquid is high purity water.

[0044] In some embodiments, the bottle cap 12 of the sampling bottle 1 is provided with a breathing valve 4 and a quick-insert sampling tube jack. The breathing valve is used to release pressure in the sampling bottle to prevent the problem of excessive pressure during sampling. The quick-insert sampling tube is inserted about 2 to 5 mm from the bottom of the sampling bottle, and the quick-insert sampling tube is connected to the sampling hose through a quick-insert structure.

[0045] In some embodiments, the sampling device further includes a primary valve 5, which is disposed on the sampling hose and is used to adjust the flow rate of the urea hydrolyzate flowing into the sampling bottle.

[0046] In the present invention, an operator controls a primary valve disposed on a sampling hose to accurately control the flow rate of the urea hydrolyzate flowing into the sampling bottle, which is beneficial to accurate sampling.

[0047] In some embodiments, the sampling device further includes a secondary valve 6, which is disposed on the sampling hose and arranged downstream of the primary valve to adjust the flow rate of the urea hydrolyzate flowing into the sampling bottle.

[0048] In the present invention, the combination of the primary valve and the secondary valve provides a dual flow control mechanism, which enables the operator to more finely adjust the flow of urea hydrolyzate flowing into the sampling bottle, which is conducive to accurate sampling. The two independent valves can be used as part of a redundant design. When one valve fails or requires maintenance, the other valve can still maintain basic operating functions, thereby improving the reliability and continuity of the sampling device.

[0049] Furthermore, the secondary valve is located downstream of the primary valve and can be quickly closed in an emergency to prevent excessive liquid from flowing into the sampling bottle, providing additional safety protection in the event of a primary valve failure or a problem with the control system.

[0050] Furthermore, setting a secondary valve can provide a more flexible response to the sampling process. In the initial stage, a larger flow rate can be set through the primary valve to quickly fill the sampling bottle, and then the flow rate can be fine-tuned through the secondary valve to ensure the accuracy and quality of the final sampling.

[0051] In some embodiments, the quick-insert sampling tube 2 includes a sampling hard tube body 21 and a quick-insert structure 22 disposed at the inlet end of the sampling hard tube body, and the quick-insert structure is used for quick-insert connection with the sampling hose.

[0052] In the present invention, a quick-insert structure is provided on the sampling hard tube body, so that an operator can quickly connect or disconnect the sampling hose with the quick-insert sampling tube, thereby improving work efficiency and meeting application scenarios requiring frequent sampling.

[0053] In some embodiments, the sampling hose includes a sampling hose body and a buckle structure disposed on the sampling hose body, the buckle structure being used to buckle the sampling hose body to the quick-insert structure. Specifically, the buckle structure is a buckle joint.

[0054] In the present invention, the buckle structure provides a mechanical locking function, ensuring that the connection between the sampling hose body and the quick-insertion structure is more secure and reliable, and preventing disconnection due to vibration or accidental pulling. In addition, the buckle connection design makes the installation and removal of the sampling hose simple and quick, reduces the time and complexity required for connection, and improves work efficiency.

[0055] In some embodiments, the material of the sampling hose includes polypropylene or polytetrafluoroethylene.

[0056] In the present invention, both polypropylene and polytetrafluoroethylene have excellent chemical stability, can resist the corrosion of urea hydrolyzate and its byproducts (such as ammonia, carbon dioxide, etc.), and ensure that the sampling hose can be used for a long time without being affected. In addition, both polypropylene and polytetrafluoroethylene can withstand high temperatures and can meet the sampling of urea hydrolyzate.

[0057] In some embodiments, the sampling device further comprises a cooling device 7, which is arranged on the periphery of the sampling bottle and is used to cool the sampling bottle. Specifically, the cooling device 7 is continuously cooled by external water, and water (or ice water) can also be added to cool the absorption liquid in the sampling bottle.

[0058] In the present invention, the cooling device can effectively reduce the temperature in the sampling bottle, preventing the high temperature from adversely affecting the chemical properties of the urea hydrolyzate sample. In addition, high-temperature sampling liquid may pose a safety risk to operators. By keeping the sampling bottle in a lower temperature range through the cooling device, the risk of scalding or other heat-related accidents can be reduced, thereby improving the safety of the operation.

[0059] In some embodiments, the sampling bottle includes a bottle body 11 and a bottle cap 12 threadedly connected to the bottle mouth of the bottle body.

[0060] In the present invention, the threaded connection design can provide good sealing performance to ensure that the urea hydrolyzate in the sampling bottle will not leak. The threaded connection design makes the opening and closing of the bottle cap simple and quick, does not require additional tools, reduces the difficulty of operation, and improves work efficiency.

[0061] In some embodiments, the sampling bottle is made of glass or polypropylene.

[0062] In the present invention, the glass material has extremely high chemical stability and is not easy to react with urea hydrolyzate and its byproducts, thereby ensuring the purity and representativeness of the sample. The glass material is transparent, which is convenient for observing the sample in the sampling bottle and helps to monitor the sampling process in real time. Polypropylene has good tolerance and corrosion resistance, and can extend the service life of the sampling bottle. Compared with glass, polypropylene is not easy to crack in low temperature environment, adapts to a wider temperature range, and increases the flexibility of use.

[0063] A specific example provided by the present invention includes: the sampling bottle is made of glass or polypropylene, the volume is 1000mL and the bottle body is scaled, the bottle cap is integrated with a breathing valve and a socket, the quick-insert sampling tube is inserted into the socket, and the bottle cap is connected to the bottle body by a thread. The quick-insert sampling tube is connected to the sampling hose by quick-insert, and the sampling hose should be a polypropylene or polytetrafluoroethylene hose with a snap-on connector, and the length of the sampling hose meets the requirements of the sampling tube of the urea hydrolyzer of the power plant (see Figure 1 ) is connected, the sampling device can be fixed in a safe position.

[0064] Before sampling, clean the sampling bottle and sampling hose thoroughly with deionized water, and add 500mL of absorption liquid to the sampling bottle until the liquid level reaches L 1 The sum of the weight of the absorption liquid and the sampling bottle (with cover) is m 1 (accurate to 0.1g).

[0065] When taking samples, operators should wear gas masks that can filter ammonia, take safety measures to prevent burns, and take safety precautions.

[0066] Specifically, 1) before sampling, the surface of the urea hydrolyzer of the power plant is drained for 30s to 60s. Specifically, the first drain valve 32 on the urea hydrolyzate sampling tube 31 is opened to flush the urea hydrolyzate sampling tube 31 (the discharged waste liquid should be collected in a waste liquid bucket and poured into a urea-specific waste liquid pool), and the first drain valve 32 is closed after flushing.

[0067] 2) Connect one end of the sampling hose to the urea hydrolyzate sampling tube, and the other end to the quick-insert sampling tube of the sampling bottle, and fix the sampling bottle.

[0068] 3) Slowly open the primary valve and the secondary valve to take samples. During the sampling process, open the breathing valve on the top of the sampling bottle to prevent obvious bubbles from appearing in the solution in the sampling bottle. When the liquid level in the sampling bottle reaches L 2 (sampling volume is about 100mL), close the primary valve and secondary valve on the sampling hose and stop sampling.

[0069] 4) Close the breathing valve on the top of the sampling bottle and disconnect the sampling hose from the urea hydrolyzate sampling tube.

[0070] 5) After the temperature of the quick-plug sampling tube drops below 40°C, disconnect the quick-plug sampling tube from the sampling hose and clean the sampling hose with absorption liquid.

[0071] 6) The sum of the weight of the sampling bottle and the mixed solution (the mixed solution includes the mixed urea hydrolyzate and absorption solution) m 2 (accurate to 0.1g). According to the mass of urea hydrolyzate (m 2 -m 1 )g, the density of urea hydrolyzate is ρg / cm 3 (density is 1.15-1.18g / cm 3 ) to determine the volume VmL of the urea hydrolyzate taken.

[0072] 7) Transfer the mixed solution in the sampling bottle to a 1000mL volumetric flask, rinse the sampling bottle with the absorption liquid for 3 times, transfer the rinse water to the volumetric flask, fix the volume to the scale for sample analysis. At this time, it can be known that the sample is diluted by 1000 / V, and the content of impurity ions in the urea hydrolyzate can be quantitatively analyzed in turn.

[0073] The urea hydrolyzer 30 of the power plant further includes a bottom drain pipe 33 and a second drain valve 34 arranged on the bottom drain pipe 33. The bottom drain pipe 33 is used to drain the bottom of the urea hydrolyzer 30. The urea hydrolyzer 30 also has a saturated steam pipeline and a drain pipeline connected to its pipe body, as well as a saturated steam pipeline for conveying NH 3 , H2 O and CO 2 Pipeline.

[0074] Another specific example provided by the present invention comprises:

[0075] Specifically, 1) before sampling, the surface of the urea hydrolyzer of the power plant is drained for 30s to 60s. Specifically, the first drain valve 32 on the urea hydrolyzate sampling tube 31 is opened to flush the urea hydrolyzate sampling tube 31 (the discharged waste liquid should be collected in a waste liquid bucket and poured into a urea-specific waste liquid pool), and the first drain valve 32 is closed after flushing.

[0076] 2) Connect one end of the sampling hose to the urea hydrolyzate sampling tube, and the other end to the quick-insert sampling tube of the sampling bottle, and fix the sampling bottle.

[0077] 3) After opening the primary valve, slowly open the secondary valve at a preset interval to take samples. During the sampling process, open the breathing valve on the top of the sampling bottle to prevent obvious bubbles from appearing in the solution in the sampling bottle. When the liquid level in the sampling bottle reaches L 2 (sampling volume is about 100mL), close the primary valve and secondary valve on the sampling hose and stop sampling.

[0078] 4) Close the breathing valve on the top of the sampling bottle and disconnect the sampling hose from the urea hydrolyzate sampling tube.

[0079] 5) After the temperature of the quick-plug sampling tube drops below 40°C, disconnect the quick-plug sampling tube from the sampling hose and clean the sampling hose with absorption liquid.

[0080] 6) The sum of the weight of the sampling bottle and the mixed solution (the mixed solution includes the mixed urea hydrolyzate and absorption solution) m 2 (accurate to 0.1g). According to the mass of urea hydrolyzate (m 2 -m 1 )g, the density of urea hydrolyzate is ρg / cm 3 (density is 1.15-1.18g / cm 3 ) to determine the volume VmL of the urea hydrolyzate taken.

[0081] 7) Transfer the mixed solution in the sampling bottle to a 1000mL volumetric flask, rinse the sampling bottle with the absorption liquid for 3 times, transfer the rinse water to the volumetric flask, fix the volume to the scale for sample analysis. At this time, it can be known that the sample is diluted by 1000 / V, and the content of impurity ions in the urea hydrolyzate can be quantitatively analyzed in turn.

[0082] refer to Figure 5 According to a second aspect of the embodiments of the present disclosure, a method for sampling urea hydrolyzate in a power plant is provided. The method is implemented according to the above-mentioned sampling device and comprises:

[0083] S101. A preset volume of absorption liquid is placed in a sampling bottle, and the outlet end of the quick-insert sampling tube is inserted to a preset depth below the surface of the absorption liquid.

[0084] S102, opening the primary valve and the secondary valve in sequence at preset time intervals to allow the urea hydrolyzate in the urea hydrolyzer of the power plant to flow into the sampling bottle.

[0085] S103. Use the breathing valve to adjust the pressure in the sampling bottle.

[0086] In the present invention, the quick-insert sampling tube is inserted below the liquid surface of the absorption liquid, which is beneficial to the absorption of the urea hydrolyzate by the absorption liquid. In addition, by inserting the quick-insert sampling tube below the liquid surface of the absorption liquid, the absorption liquid can be used to cool the quick-insert sampling tube, avoiding the risk of high-temperature burns to operators, and can also effectively inhibit the flashing of the sampling solution. Furthermore, by setting a breathing valve at the bottle mouth of the sampling bottle to adjust the pressure in the sampling bottle, it can effectively prevent the sample from leaking or splashing due to pressure changes, thereby improving the safety of the operation.

[0087] Furthermore, the design of opening the valves in sequence at preset intervals avoids sudden flow changes or pressure fluctuations that may be caused by opening two valves at the same time, reducing safety hazards caused by improper operation.

[0088] In some embodiments, it also includes:

[0089] S104. Weigh the weight of the sampling bottle and the absorption liquid before sampling m 1 .

[0090] S105. Weigh the weight of the sampling bottle and the mixed solution after sampling m 2 , wherein the mixed liquid includes absorption liquid and urea hydrolyzate.

[0091] S106, according to weight m 1 and weight m 2 Calculate the weight of urea hydrolyzate in the sampling bottle (m 2 -m 1 )g, and determine the volume VmL of the urea hydrolyzate taken according to the density of the urea hydrolyzate.

[0092] S107, transferring the mixed solution in the sampling bottle to a volumetric flask and adjusting the volume to a preset volume, and determining the dilution multiple of the urea hydrolyzate according to the volume VmL of the urea hydrolyzate and the preset volume of the volumetric flask.

[0093] S108. Analyze the content of impurity ions in the urea hydrolyzate according to the dilution multiple of the urea hydrolyzate.

[0094] A specific example provided by the present invention includes:

[0095] Before sampling, add 500 mL of absorption liquid to the sampling bottle until the liquid level reaches L 1 The sum of the weight of the absorption liquid and the sampling bottle (with cover) is m 1 (accurate to 0.1g).

[0096] When the liquid level in the sampling bottle reaches L 2 (sampling volume is about 100mL), close the primary valve and the secondary valve and stop sampling.

[0097] The sum of the weight of the sampling bottle and the mixed liquid is m 2 (accurate to 0.1g), the mass of urea hydrolyzate is (m 2 -m 1 )g, the density of urea hydrolyzate is ρg / cm 3 (The density of urea hydrolyzate is 1.15~1.18g / cm 3 ), the volume VmL of the urea hydrolyzate taken can be determined.

[0098] Transfer all the solution in the sampling bottle to a 1000mL volumetric flask, rinse the sampling bottle with reagent water for 3 times, transfer the rinse water to the volumetric flask, and dilute to 1000mL for sample analysis. At this time, it can be known that the sample is diluted by 1000 / VmL, and the content of impurity ions in the urea hydrolyzate can be quantitatively analyzed in turn.

[0099] The specific calculation steps include: measuring the sum of the weight of the absorption liquid and the sampling bottle (with cover) m 1 .

[0100] Measure the total weight of the sampling bottle (with cover) filled with the mixed liquid m 2 .

[0101] Calculate the mass of urea hydrolyzate:

[0102] m urea =m 2 -m 1

[0103] Compute volume using a density range:

[0104] The density of urea hydrolyzate is in the range of 1.15-1.18 g / cm 3 .

[0105] The average density value used is ρ = 1.165 g / cm 3 (i.e. (1.15+1.18) / 2), the volume V of urea hydrolyzate can be calculated urea :

[0106] V urea =m urea / 1.165

[0107] Perform sample analysis, including:

[0108] Transfer the mixed solution: Carefully transfer the mixed solution in the sampling bottle to a 1000mL volumetric flask.

[0109] Rinse the sampling bottle: Rinse the sampling bottle 3 times with the absorption liquid to ensure that all the residual mixed liquid is transferred to the volumetric flask.

[0110] Make up the volume: Add absorption liquid to the volumetric flask until the liquid reaches the 1000mL mark.

[0111] Determine the dilution multiple: At this point, the sample is diluted by 1000 / V urea .

[0112] Quantitative analysis of impurity ions: The fixed-volume solution is used for further chemical analysis, such as atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS) or other appropriate analytical methods to determine the content of impurity ions in the urea hydrolyzate.

[0113] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A urea hydrolyzate sampling device for a power plant, characterized in that: include: Sampling bottles; A weighing device, which is arranged on the sampling bottle and is used to weigh the mass of the absorption liquid in the sampling bottle and, after sampling, to weigh the mass of the mixed liquid in the sampling bottle, wherein the mixed liquid includes the absorption liquid and the urea hydrolyzate; A quick-insert sampling tube, which is inserted into the sampling bottle; the quick-insert sampling tube is a hard tube; A sampling hose, one end of which is connected to the inlet end of the quick-plug sampling tube, and the other end of which is used to be connected to the urea hydrolyzer of the power plant; A breathing valve, which is arranged at the mouth of the sampling bottle and is used to adjust the pressure in the sampling bottle; During sampling, the outlet end of the quick-insert sampling tube extends into the sampling bottle to a preset depth below the surface of the absorption liquid, so that the absorption liquid can absorb the urea hydrolyzate and cool the quick-insert sampling tube.

2. A urea hydrolyzate sampling device for a power plant according to claim 1, characterized in that: Also includes: A primary valve is provided on the sampling hose and is used to adjust the flow rate of the urea hydrolyzate flowing into the sampling bottle.

3. A urea hydrolyzate sampling device for a power plant according to claim 1 or 2, characterized in that: Also includes: A secondary valve is provided on the sampling hose and arranged downstream of the primary valve to adjust the flow rate of the urea hydrolyzate flowing into the sampling bottle.

4. A urea hydrolyzate sampling device for a power plant according to claim 1 or 2, characterized in that: The quick-insert sampling tube comprises a sampling hard tube body and a quick-insert structure arranged at the inlet end of the sampling hard tube body, and the quick-insert structure is used for quick-insert connection with the sampling hose.

5. A urea hydrolyzate sampling device for a power plant according to claim 4, characterized in that: The sampling hose comprises a sampling hose body and a buckle structure arranged on the sampling hose body, and the buckle structure is used to buckle the sampling hose body to the quick-insert structure.

6. A urea hydrolyzate sampling device for a power plant according to claim 1 or 2, characterized in that: The material of the sampling hose includes polypropylene or polytetrafluoroethylene.

7. A urea hydrolyzate sampling device for a power plant according to claim 1 or 2, characterized in that: Also includes: A cooling device is arranged on the periphery of the sampling bottle and is used to cool the sampling bottle.

8. A urea hydrolyzate sampling device for a power plant according to claim 1 or 2, characterized in that: The sampling bottle comprises a bottle body and a bottle cap threadedly connected to the bottle mouth of the bottle body.

9. A method for sampling urea hydrolyzate in a power plant, the method being implemented by the sampling device according to any one of claims 1 to 8, characterized in that: include: A preset volume of absorption liquid is placed in the sampling bottle, and the outlet end of the quick-insert sampling tube is inserted into a preset depth below the surface of the absorption liquid; Opening the primary valve and the secondary valve in sequence at preset intervals to allow the urea hydrolyzate in the urea hydrolyzer of the power plant to flow into the sampling bottle; The breathing valve is used to adjust the pressure in the sampling bottle.

10. A method for sampling urea hydrolyzate in a power plant according to claim 9, characterized in that: Also includes: Weigh the weight of the sampling bottle and the absorption liquid before sampling m1; Weigh the weight m2 of the sampling bottle and the mixed liquid after sampling, wherein the mixed liquid includes the absorption liquid and the urea hydrolyzate; Calculate the weight of the urea hydrolyzate in the sampling bottle (m2-m1) g according to the weight m1 and the weight m2, and determine the volume V mL of the urea hydrolyzate taken according to the density of the urea hydrolyzate; The mixed solution in the sampling bottle is transferred to a volumetric flask and fixed to a preset volume, and the dilution multiple of the urea hydrolyzate is determined according to the volume VmL of the urea hydrolyzate and the preset volume of the volumetric flask; The content of impurity ions in the urea hydrolyzate is analyzed according to the dilution multiple of the urea hydrolyzate.

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