Marine multi-point ammonia leakage monitoring system

Abstract

The invention relates to a multi-point ammonia leakage monitoring system for a ship. The multi-point ammonia leakage monitoring system consists of a gas analysis host and a circulating sampling system, the circular sampling system is used for circularly extracting sample gas of a plurality of specified sampling points one by one and conveying the sample gas to the gas analysis host; the gas analysis host comprises an absorption cell for receiving sample gas, a laser, a laser driving module, a photoelectric detector, a signal processing module and a display alarm module; the laser driving module is used for driving and modulating laser output by the laser device, the laser enters the absorption cell, is reflected for multiple times, is absorbed by ammonia gas in sample gas, is reflected out of the absorption cell through a light outlet of the absorption cell, and is collected by the photoelectric detector; the photoelectric detector converts a light intensity signal into a current signal, the signal processing module receives the current signal, processes and converts the current signal into ammonia concentration information and sends the ammonia concentration information to the display alarm module, and when an internal threshold value is exceeded, alarm information is sent to the display alarm module and a ship master control room. The ammonia gas leakage monitoring device can monitor the ammonia gas leakage concentration in real time and provide ammonia gas leakage alarm information.

Description

Technical Field

[0001] The invention relates to the technical field of environmental safety monitoring, and in particular to a marine multi-point ammonia leakage monitoring system. Background Art

[0002] Existing ammonia leakage monitoring mainly uses electrochemical sensors, which are low-cost and easy to deploy, but are easily interfered by other gases, have low detection accuracy, high false alarm rate, and high concentration of ammonia can easily cause sensor poisoning and failure. The maintenance cost is very high and is not suitable for monitoring ammonia leakage on ammonia-fueled ships. Summary of the invention

[0003] In view of this, the present invention provides a marine multi-point ammonia leakage monitoring system, which monitors the ammonia leakage concentration in the fuel supply system area of ​​the ammonia fuel ship in real time and provides ammonia leakage alarm information.

[0004] The present invention is realized through the following technical scheme: a ship-based multi-point ammonia leakage monitoring system, which is composed of a gas analysis host and a circulation sampling system; the circulation sampling system is used to circulate and extract sample gases from several designated sampling points one by one and transmit them to the gas analysis host; the gas analysis host includes an absorption cell for receiving sample gas, a laser, a laser driving module, a photoelectric detector, a signal processing module and a display alarm module; the laser driving module is used to realize the driving and modulation of the laser output laser, the laser is incident on the absorption cell and is absorbed by the ammonia in the sample gas after multiple reflections, and then reflected out of the absorption cell from the light outlet of the absorption cell and collected by the photoelectric detector, the photoelectric detector is used to convert the light intensity signal into a current signal, the signal processing module is used to receive the current signal and process it into ammonia concentration information and send it to the display alarm module, and at the same time, when the internal threshold is exceeded, an alarm message is sent to the display alarm module and the ship main control room; the display alarm module is used to display the ammonia concentration information and the alarm message.

[0005] Furthermore, the circulating sampling system includes a control module, a sampling pump, an air outlet pipeline, a sampling pipeline and an electromagnetic valve I; several sampling points are connected to the air extraction end of the sampling pump through the corresponding sampling pipelines, each sampling pipeline is provided with a corresponding electromagnetic valve I, and the air outlet end of the sampling pump is connected to the absorption tank through the air outlet pipeline; the control module realizes the extraction of sample gas from the corresponding sampling point by controlling the opening of the electromagnetic valve I.

[0006] Furthermore, there are several sampling pumps, and each sampling pump is provided with a solenoid valve II on its outlet pipe; the control module is also used to control the opening and closing of the solenoid valve II, when the solenoid valve II is opened, the sample gas is delivered to the absorption tank, and when the solenoid valve II is closed, the sample gas is discharged to the external environment; at least two solenoid valves I are opened at the same time, and the solenoid valves I in the open state are all connected to different sampling pumps, and at most one of the sampling pumps has its corresponding solenoid valve II opened.

[0007] Furthermore, the gas analysis host also includes a power module, which is used to convert the external 220V into 24V, 5V and 3.3V to power the laser driving module, the signal processing module and the sampling control module respectively.

[0008] Furthermore, the laser adopts a 1512nm DFB laser, and the laser driving module loads the driving current of the superimposed modulation signal to the laser driving end, so that the laser emits laser that can be absorbed by the gas to be detected.

[0009] Furthermore, the laser driving module can also drive a TEC controller of the laser to control the temperature of the laser.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. The present invention solves the drawbacks of existing electrochemical sensors, and utilizes laser absorption spectroscopy and multi-point cycle sampling to achieve multi-point leakage online monitoring of gases including ammonia, thereby improving the environmental safety of ammonia fuel ships and avoiding personal and property losses caused by ammonia leakage.

[0012] 2. In the present invention, at least two sampling pumps simultaneously open a solenoid valve I connected thereto, and at most one solenoid valve II corresponding to the sampling pump is opened, that is, the cyclic sampling system improves the sample gas replacement efficiency and accelerates the response speed by pre-sampling.

[0013] 3. The present invention only requires a single set of gas analysis host consisting of a laser, a photoelectric detector and a signal processing module, combined with a circular sampling system, to achieve real-time online monitoring of multi-point leakage, with high detection accuracy, fast response, extremely low false alarm rate and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] The present invention provides a marine multi-point ammonia leakage monitoring system, such as Figure 1 As shown, the system consists of an ammonia analysis host and a circulation sampling system; the circulation sampling system is used to circulate and extract the sample gas from the designated sampling points one by one and transmit it to the ammonia analysis host; the ammonia analysis host includes an absorption cell for receiving the sample gas, a laser, a laser driving module, a photoelectric detector, a signal processing module and a display alarm module.

[0017] The laser driving module is used to realize the driving and modulation of the laser output. The laser driving module can make the laser emit a laser that can be absorbed by ammonia. The laser is incident on the absorption cell, absorbed by the sample gas after multiple reflections, and then reflected out of the absorption cell from the light outlet of the absorption cell and incident on the photodetector, that is, collected by the photodetector. The photodetector is used to convert the light intensity signal after the ammonia in the sample gas is absorbed into a current signal, and send the current signal to the signal processing module. The signal processing module is used to receive the current signal and process it into ammonia concentration information. Specifically, the signal processing module processes the current signal to obtain a voltage signal related to the ammonia concentration, inverts the ammonia concentration in the absorption cell according to the built-in program, and sends the ammonia concentration information to the display alarm module; at the same time, it will also judge according to the built-in program, and send an alarm message to the display alarm module and the ship's main control room when it exceeds the built-in threshold; the display alarm module is used to display ammonia concentration information and alarm information. The ammonia analysis host uses laser absorption spectroscopy to detect ammonia concentration, with high detection accuracy, extremely low false alarm rate, and high reliability.

[0018] The circulating sampling system includes a control module, a sampling pump, an air outlet pipeline, a sampling pipeline and a solenoid valve I; several sampling points are connected to the air extraction end of the sampling pump through the corresponding sampling pipelines, each sampling pipeline is provided with a corresponding solenoid valve I, and the air outlet end of the sampling pump is connected to the absorption tank through the air outlet pipeline; the control module realizes the extraction of sample gas from the corresponding sampling point by controlling the opening of the solenoid valve I.

[0019] As an improvement, several sampling pumps are provided, and each sampling pump is provided with a solenoid valve II on its outlet pipe; the control module is also used to control the opening and closing of the solenoid valve II. When the solenoid valve II is opened, the extracted sample gas is delivered to the absorption tank, and when the solenoid valve II is closed, the extracted sample gas is discharged to the external environment. In this embodiment, the cyclic sampling system adopts a multi-point cyclic sampling method, that is, the solenoid valve I on the sampling pipeline is opened in sequence according to a predetermined logical cycle, and the sample gas at the designated sampling point is drawn into the ammonia analysis host for detection by the sampling pump. After the sample gas at one sampling point is delivered to the ammonia analysis host, the sample gas at the next sampling point is extracted. Since the sampling pipeline is long, it takes a certain amount of time to draw the sample gas at the next sampling point to the outlet pipe, and the sample gas replacement efficiency is too low. Therefore, in order to improve the sample gas replacement efficiency and speed up the response speed, the cyclic sampling system adopts a pre-sampling method.

[0020] Specifically, the control system enables at least two solenoid valves I to be opened at the same time to extract sample gas, and the solenoid valves I in the open state are all connected to different sampling pumps, that is, at least two sampling pumps work at the same time, and only one solenoid valve I connected to it is opened respectively, so that at least two sampling pumps extract sample gas from a sampling point connected to it at the same time (at least the sample gas of two sampling points is extracted separately at the same time), but at most only one solenoid valve IIA corresponding to sampling pump A is opened to deliver sample gas A to the absorption pool, and the solenoid valves II on the outlet pipes of the other sampling pumps are closed to discharge the continuously extracted sample gas into the external environment. After the sample gas A is detected, its corresponding solenoid valve IIA is closed, and the solenoid valve IIB of the next sampling pump B that is extracting sample gas B is opened according to the predetermined logic to deliver sample gas B to the absorption pool. Since the sample gas B is being continuously extracted, it only needs to open the solenoid valve IIB to enter the absorption pool for detection. Compared with opening the solenoid valve IB to extract gas when the sample gas B needs to be detected, the time of the sample gas B in the sampling pipeline is greatly reduced, the sample gas replacement efficiency is improved, and the response speed is accelerated.

[0021] The ammonia analysis host also includes a power module, which is used to convert the external 220V voltage into 24V, 5V and 3.3V voltages, respectively, to power the laser drive module, the signal processing module and the sampling control module. In a specific implementation of the present invention, a cabinet design can be adopted, for example, the ammonia analysis host is installed on the upper part of the cabinet, the circulating sampling system control module is arranged at the lower part of the cabinet, and the sampling pipeline, the air outlet pipeline, the sampling pump and the solenoid valve I and the solenoid valve II are arranged on the rear panel; the cabinet is powered by an external 220V.

[0022] The laser can be a 1512nm DFB laser. The laser driving module loads the driving current of the superimposed modulated signal to the laser driving end, so that the laser emits a laser of a specified wavelength. The laser driving module can also drive the TEC controller of the laser to control the temperature of the laser, which is generally 25°C. The output light of the laser can be connected to the absorption cell through an optical fiber. After being absorbed by the gas, each laser is incident on the photodetector through the light outlet of the absorption cell. In this embodiment, ammonia leakage is detected. The present invention can be used to detect other gases. It is only necessary to modulate the laser emitted by the laser to a wavelength that can be absorbed by the gas to be detected, and modify the internal program of the signal processing module that inverts the voltage signal to obtain the gas concentration accordingly, so as to realize the detection of other gases.

[0023] After testing, the present invention can quickly and effectively monitor the ammonia concentration at multiple locations, has high detection accuracy, short response time, is not interfered by other gases, has a long service life, and is very suitable for ammonia leakage monitoring in the shipping industry.

[0024] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A marine multi-point ammonia leakage monitoring system, characterized in that: It consists of a gas analysis host and a circulation sampling system; the circulation sampling system is used to circulate and extract sample gas from several designated sampling points one by one and transmit it to the gas analysis host; the gas analysis host includes an absorption cell for receiving sample gas, a laser, a laser driving module, a photoelectric detector, a signal processing module and a display alarm module; The laser driving module is used to realize the driving and modulation of the laser output. The laser is incident on the absorption cell and is absorbed by the ammonia in the sample gas after multiple reflections. It is then reflected out of the absorption cell from the light outlet of the absorption cell and collected by the photoelectric detector. The photoelectric detector is used to convert the light intensity signal into a current signal. The signal processing module is used to receive the current signal and process it into ammonia concentration information and send it to the display alarm module. At the same time, when the internal threshold is exceeded, an alarm message is sent to the display alarm module and the ship's main control room. The display alarm module is used to display the ammonia concentration information and alarm information.

2. The marine multi-point ammonia leakage monitoring system according to claim 1, characterized in that: The circulating sampling system includes a control module, a sampling pump, an air outlet pipeline, a sampling pipeline and a solenoid valve I; several sampling points are connected to the air extraction end of the sampling pump through the corresponding sampling pipelines, each sampling pipeline is provided with a corresponding solenoid valve I, and the air outlet end of the sampling pump is connected to the absorption tank through the air outlet pipeline; the control module realizes the extraction of sample gas from the corresponding sampling point by controlling the opening of the solenoid valve I.

3. The marine multi-point ammonia leakage monitoring system according to claim 2, characterized in that: There are several sampling pumps, and each sampling pump is equipped with a solenoid valve II on its outlet pipe; The control module is also used to control the opening and closing of solenoid valve II. When solenoid valve II is opened, the sample gas is transported to the absorption tank, and when solenoid valve II is closed, the sample gas is discharged to the external environment. At least two solenoid valves I are opened at the same time, and the solenoid valves I in the open state are connected to different sampling pumps, and at most one of the sampling pumps has its corresponding solenoid valve II opened.

4. The marine multi-point ammonia leakage monitoring system according to claim 1, characterized in that: The gas analysis host also includes a power module, which is used to convert the external 220V into 24V, 5V and 3.3V to power the laser drive module, the signal processing module and the sampling control module respectively.

5. The marine multi-point ammonia leakage monitoring system according to any one of claims 1 to 4, characterized in that: The laser uses a 1512nm DFB laser. The laser driving module loads the driving current of the superimposed modulation signal to the laser driving end, so that the laser emits laser that can be absorbed by the gas to be detected.

6. The marine multi-point ammonia leakage monitoring system according to claim 5, characterized in that: The laser driver module can also drive the laser's TEC controller to control the laser's temperature.

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