Steam condensation experimental device for accurately measuring instantaneous flow of condensed water

Abstract

The application discloses a steam condensation experimental device for accurately measuring instantaneous flow of condensed water and belongs to the technical field of condensation heat transfer experimental measurement. The steam condensation experimental device for accurately measuring instantaneous flow of condensed water can solve the problem that most of the existing experimental devices cannot measure the flow of condensed water in real time, and comprises a condensed water collecting system, wherein the condensed water collecting system is connected with a steam-water separation system, the condensed water collecting system comprises a condensate tank for collecting condensed water, a liquid level detection mechanism for measuring the change of the liquid level in the condensate tank in real time and a temperature detection mechanism for detecting the temperature of the condensed liquid in real time are arranged in the condensate tank, and the liquid level detection mechanism is connected with a data acquisition system. The mass flow of the condensed liquid flowing into the condensate tank can be calculated in real time through the liquid level height and the liquid density of the condensed liquid, and the size of the condensation heat transfer amount and the condensation heat transfer coefficient of the experimental section at different moments can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of experimental measurement technology of condensation heat transfer, and specifically relates to a steam condensation experimental device for accurately measuring the instantaneous flow rate of condensate. Background Technology

[0002] In-tube condensation heat transfer is a major physical phenomenon in condenser operation, playing a crucial role in chemical production, HVAC, and seawater desalination. During in-tube condensation heat transfer, the flow of steam within the tubes is limited by the tube type and length, while the flow and distribution of the condensate film are directly influenced by wall boundary conditions and external heat transfer processes. The overall heat transfer process is bidirectionally coupled. Therefore, a correct understanding of the phase change heat transfer characteristics of steam within the tubes is of great significance for the safe and stable operation of phase change heat exchangers.

[0003] Due to the complexity of condensation heat transfer, existing numerical simulation techniques are not yet perfect in directly simulating condensation heat transfer. Most mainstream models require the reasonable use of empirical parameters, and the selection of these empirical parameters generally involves a large amount of trial and error. Currently, research on condensation heat transfer in pipes is mostly focused on experimental studies. Some researchers use equipment such as steam generators and shell-and-tube heat exchangers to build condensation heat transfer devices, measuring thermal parameters such as steam flow rate, pipe wall temperature, temperature within the shell-and-tube annulus, and condensate flow rate, and combining this with some visualization devices to obtain condensation heat transfer data under different operating conditions. However, most existing experimental devices have the limitation of not being able to measure condensate flow rate in real time. Accurate measurement of condensate mass flow rate is of great significance for the study of condensation heat transfer characteristics in pipes and the study of condensation flow regime transformation. Summary of the Invention

[0004] To address the problems in the prior art, the present invention provides a steam condensation experimental apparatus for accurately measuring the instantaneous flow rate of condensate.

[0005] The technical solution adopted in this invention is as follows:

[0006] A steam condensation experimental apparatus for accurately measuring the instantaneous flow rate of condensate includes a condensate collection system connected to a steam-water separation system. The condensate collection system includes a condensate tank for collecting condensate. The condensate tank is equipped with a level detection mechanism for real-time measurement of the liquid level change and a temperature detection mechanism for real-time detection of the condensate temperature. The level detection mechanism is connected to a data acquisition system.

[0007] After adopting this technical solution, the residual steam and condensate after heat exchange enter the steam-liquid separation system for steam-liquid separation. The separated condensate enters the condensate tank. The capacitive level gauge and thermocouple in the condensate tank measure the condensate height and condensate temperature in the tube, respectively. The liquid density can be obtained from the condensate temperature. The mass flow rate of the condensate flowing into the condensate tank can be calculated in real time from the condensate level and liquid density. By measuring the liquid level, the amount of heat exchanged during condensation can be accurately reflected. The mass flow rate of the condensate can be obtained from the rate of change of the liquid level in the condensate tank. The amount of heat transfer during condensation and the condensation heat transfer coefficient at different times in the experimental section can be obtained.

[0008] Preferably, the condensate tank is also equipped with a liquid level control system.

[0009] With this technical solution, when the liquid level in the condensate tank is close to the actual height of the condensate tank, the liquid level control system will discharge the excess condensate from the condensate tank, thereby achieving uninterrupted measurement of the entire device.

[0010] Preferably, the liquid level control system includes a first liquid level probe and a second liquid level probe disposed inside the condensate tank. The first liquid level probe is disposed at the top of the condensate tank, and the second liquid level probe is disposed at the bottom of the condensate tank. Both the first liquid level probe and the second liquid level probe are electrically connected to a liquid level controller, and the liquid level controller is electrically connected to a solenoid valve for controlling the discharge of condensate water in the condensate tank.

[0011] With this technical solution, when the liquid level probe at the top detects that the liquid level in the condensate tank is close to the actual height of the condensate tank, the liquid level controller will open the solenoid valve at the bottom of the condensate tank to discharge excess condensate, thereby achieving uninterrupted measurement of the entire device.

[0012] Preferably, the upper part of the condensate tank is provided with a condensate inlet, a temperature measuring hole, and a liquid level measuring hole. The condensate inlet is connected to the steam-water separation system, the temperature measuring hole is used to install a temperature detection mechanism, and the liquid level measuring hole is used to install a liquid level detection mechanism.

[0013] Preferably, the first and second liquid level probes are located at least 1 / 10 of the total height of the condensate tank from the top and bottom of the condensate tank.

[0014] This technical solution provides a safety margin for measuring the liquid level in the condensate tank.

[0015] Preferably, the vapor-liquid separation system includes a vapor-liquid separator, which includes a vapor-liquid mixture inlet, a vapor-liquid separation orifice plate, a steam outlet, and a condensate outlet, wherein the condensate outlet is connected to a condensate collection system.

[0016] After adopting this technical solution, the steam-water mixture flowing out of the heat exchange section enters the steam-liquid separator. The steam flows through the steam-water separation orifice plate and flows out from the steam outlet, while the condensate enters the condensate tank due to gravity.

[0017] Preferably, the data acquisition system includes a data acquisition instrument and a computer electrically connected to the data acquisition instrument.

[0018] After adopting this technical solution, the data acquisition instrument can calculate the mass flow rate into the condensate tank in real time based on the density data and liquid level change data of the obtained condensate, and store the real-time data in the computer for easy query.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0020] 1. The present invention has a simple and reliable structure, long service life, fast measurement speed, and high measurement accuracy. It can quickly cope with complex experimental conditions with rapid changes in condensate flow rate, and makes up for the condensate measurement problem of most current tube condensation experimental devices.

[0021] 2. The present invention has a reasonable structural design, low cost, is easy to implement, and requires no maintenance. It can be widely used in various experimental devices for steam condensation in tubes and is suitable for most steam media and a wide range of steam pressure distributions.

[0022] 3. The liquid level measurement method used in this invention can accurately reflect the amount of heat transferred during condensation. The mass flow rate of the condensate can be obtained from the rate of change of the liquid level in the condensate tank, and the amount of heat transfer during condensation and the condensation heat transfer coefficient can be obtained at different times in the experimental section.

[0023] 4. When the liquid level in the condensate tank is close to the actual height of the condensate tank, the liquid level control system will discharge the excess condensate from the condensate tank, thereby achieving uninterrupted measurement of the entire device. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the present invention when applied to a condensation heat transfer experimental platform.

[0026] Among them, 1-vapor-liquid mixture inlet, 2-first valve, 3-vapor-liquid separator, 4-check valve, 5-third valve, 6-steam outlet, 7-armored thermocouple, 8-capacitive level gauge, 9-data acquisition instrument, 10-computer, 11-first level probe, 12-condensate tank, 13-level controller, 14-second level probe, 15-drain pipe, 16-solenoid valve, 17-insulation layer, 18-heat exchanger, 19-steam generator, 20-water tank. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] A steam condensation experimental apparatus for accurately measuring the instantaneous flow rate of condensate includes a condensate collection system connected to a steam-water separation system. The condensate collection system includes a condensate tank 12 for collecting condensate. The condensate tank 12 is equipped with a level detection mechanism for real-time measurement of the liquid level change within the condensate tank 12 and a temperature detection mechanism for real-time detection of the condensate temperature. The level detection mechanism is connected to a data acquisition system.

[0030] In this embodiment, a liquid level control system is also provided inside the condensate tank 12.

[0031] In this embodiment, the liquid level control system includes a first liquid level probe 11 and a second liquid level probe 14 disposed in the condensate tank 12. The first liquid level probe 11 is disposed at the top of the condensate tank 12, and the second liquid level probe 14 is disposed at the bottom of the condensate tank 12. Both the first liquid level probe 11 and the second liquid level probe 14 are electrically connected to a liquid level controller 13. The liquid level controller 13 is electrically connected to a solenoid valve 16 for controlling the discharge of condensate water in the condensate tank 12.

[0032] In this embodiment, the liquid level controller 13 is connected to a 220V power supply, and a liquid level control switch is provided on the liquid level controller 13.

[0033] In this embodiment, the upper part of the condensate tank 12 is provided with a condensate inlet, a temperature measuring hole and a liquid level measuring hole. The condensate inlet is connected to the steam-water separation system, the temperature measuring hole is used to install a temperature detection mechanism, and the liquid level measuring hole is used to install a liquid level detection mechanism.

[0034] In this embodiment, the temperature detection mechanism includes an armored thermocouple 7 installed inside the condensate tank 12, and the liquid level detection mechanism includes a capacitive liquid level gauge 8 installed inside the condensate tank 12. The lengths of the armored thermocouple 7 and the capacitive liquid level gauge need to be determined according to the size of the condensate tank 12, and are generally 9 / 10 of the height of the condensate tank 12.

[0035] In this embodiment, the first liquid level probe 11 and the second liquid level probe 14 are at least 1 / 10 of the total height of the condensate tank 12 from the top and bottom of the condensate tank 12.

[0036] In this embodiment, the steam-liquid separation system includes a steam-liquid separator 3. The steam-liquid separator 3 includes a steam-liquid mixture inlet 1, a steam-liquid separation orifice plate, a steam outlet 6, and a condensate outlet. The condensate outlet is connected to a condensate collection system. The steam outlet 6 is connected to a water tank 20 via a pipe. A check valve 4, a second valve 5, and a heat exchanger 18 are installed on the pipe connecting the steam outlet 6 and the water tank. The check valve 4 is used to prevent steam backflow, which could interfere with the experimental results. The steam-liquid mixture inlet 1 is connected to a condensation heat transfer experimental platform via a pipe. A first valve 2 is installed on the pipe connecting the steam-liquid mixture inlet 1 and the condensation heat transfer experimental platform. The condensation heat transfer experimental platform includes a steam generator.

[0037] In this embodiment, the size of the condensate tank 12 in the condensate collection system needs to be verified and determined. The approximate water flow rate entering the condensate tank 12 is determined based on the actual in-pipe steam condensation experiment, and the actual size of the condensate tank 12 is determined according to the algorithm of water flow rate × experiment duration / condensate density.

[0038] In this embodiment, the condensate tank 12 is provided with a heat preservation mechanism, which is a glass wool heat preservation sleeve installed on the outside of the condensate tank.

[0039] In this embodiment, the data acquisition system includes a data acquisition instrument 9 and a computer 10 electrically connected to the data acquisition instrument 9.

[0040] Reference Figure 1 and Figure 2 The method of using this invention when applied to a condensation heat transfer experimental platform is as follows:

[0041] The steam-water mixture generated by the condensation heat transfer experimental platform is separated by the steam-water separation system. The steam enters the steam-liquid separator 3 from the steam-liquid mixture inlet 1. The steam flows through the steam-water separation orifice plate and exits from the steam outlet 6. After heat exchange in the heat exchanger 18, the steam becomes condensate and is collected in the water tank 20. The condensate separated in the steam-liquid separator 3 enters the condensate tank 12 through the condensate inlet due to gravity. The first liquid level probe 11 and the second liquid level probe 14 in the condensate tank 12 continuously monitor the liquid level. When the condensate tank 12 is about to be full, the liquid level control... The level controller 13 opens the solenoid valve 16 to discharge excess condensate. When the second level probe 14 detects that the liquid level is lower than the plane where the second level probe 14 is located, the level controller 13 closes the solenoid valve 16 to stop the discharge. The armored thermocouple 7 collects the temperature of the condensate inside the condensate tank 12 in real time, and the capacitive level gauge 8 monitors the height of the condensate inside the condensate tank 12 in real time. The monitored temperature data and liquid level height data are transmitted to the data acquisition instrument 9 in real time. The data acquisition instrument 9 converts the measured temperature and liquid level height into the mass flow rate of the condensate in real time and saves the data in the computer.

[0042] The above embodiments demonstrate that the liquid level measurement method used in this invention can accurately reflect the amount of heat transferred during condensation. The mass flow rate of condensate can be obtained from the rate of change of the liquid level in the condensate tank, and the amount of heat transfer and the condensation heat transfer coefficient of the experimental section at different times can be obtained, thus overcoming the current difficulty in real-time measurement of condensate flow rate in pipes under unsteady conditions.

[0043] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A steam condensation experimental device for accurately measuring the instantaneous flow rate of condensate water, characterized in that: The system includes a condensate collection system connected to a vapor-water separation system. The condensate collection system includes a condensate tank (12) for collecting condensate. The condensate tank (12) is equipped with a liquid level detection mechanism for real-time measurement of liquid level changes and a temperature detection mechanism for real-time detection of condensate temperature. The liquid level detection mechanism is connected to a data acquisition system. The condensate tank (12) is also equipped with a liquid level control system; The liquid level control system includes a first liquid level probe (11) and a second liquid level probe (14) installed in the condensate tank (12). The first liquid level probe (11) is installed at the top of the condensate tank (12), and the second liquid level probe (14) is installed at the bottom of the condensate tank (12). Both the first liquid level probe (11) and the second liquid level probe (14) are electrically connected to a liquid level controller (13). The liquid level controller (13) is electrically connected to a solenoid valve (16) for controlling the discharge of condensate in the condensate tank (12). The vapor-liquid separation system includes a vapor-liquid separator (3), which includes a vapor-liquid mixture inlet (1), a vapor-liquid separation orifice plate, a steam outlet (6), and a condensate outlet. The condensate outlet is connected to a condensate collection system. The vapor-liquid mixture inlet (1) is connected to a condensation heat transfer experimental platform via a pipe. The condensation heat transfer experimental platform includes a steam generator. The data acquisition system includes a data acquisition instrument (9) and a computer (10) electrically connected to the data acquisition instrument (9). The data acquisition instrument (9) is used to calculate the real-time density of the condensate based on the real-time liquid level change data collected by the liquid level detection mechanism and the real-time temperature data collected by the temperature detection mechanism, and to calculate the instantaneous mass flow rate of the condensate flowing into the condensate tank (12) in real time by combining the liquid level change rate and the cross-sectional area of ​​the condensate tank (12).

2. The steam condensation experimental device for accurately measuring the instantaneous flow of condensed water according to claim 1, characterized in that: The first liquid level probe (11) and the second liquid level probe (14) are at least 1 / 10 of the total height of the condensate tank (12) from the top and bottom of the condensate tank (12).

3. The steam condensation experimental device for accurately measuring the instantaneous flow of condensed water according to claim 1 or 2, characterized in that: The upper part of the condensate tank (12) is provided with a condensate inlet, a temperature measuring hole and a liquid level measuring hole. The condensate inlet is connected to the steam-water separation system. The temperature measuring hole is used to install a temperature detection mechanism and the liquid level measuring hole is used to install a liquid level detection mechanism.

4. The steam condensation experimental device for accurately measuring the instantaneous flow of condensed water according to claim 1 or 2, characterized in that: The condensate tank (12) is equipped with a heat preservation mechanism.

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