Marine multi-point ammonia leakage monitoring system

Abstract

The utility model 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 drives and modulates laser output by the laser, the laser enters the absorption cell, is absorbed by ammonia gas in sample gas after being reflected for multiple times, 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 alarm information is sent to the display alarm module and a ship master control room when an internal threshold value is exceeded. 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] This utility model relates to the field of environmental safety monitoring technology, and in particular to a marine multi-point ammonia leak monitoring system. Background Technology

[0002] Existing ammonia leak monitoring mainly uses electrochemical sensors, which are low in cost and easy to deploy. However, they are susceptible to interference from other gases, have low detection accuracy, high false alarm rate, and high concentrations of ammonia can easily cause sensor poisoning and failure, resulting in high maintenance costs. Therefore, they are not suitable for monitoring ammonia leaks on ammonia-fueled ships. Utility Model Content

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

[0004] This utility model is achieved through the following technical solution: a marine multi-point ammonia leak monitoring system, comprising a gas analysis host and a circulating sampling system; the circulating sampling system is used to circulate and extract sample gas from several designated sampling points one by one and deliver it to the gas analysis host; the gas analysis host includes an absorption cell for receiving sample gas, a laser, a laser drive module, a photodetector, a signal processing module, and a display and alarm module; the laser drive module is used to drive and modulate the laser output; the laser is incident on the absorption cell and, after multiple reflections, is absorbed by the ammonia in the sample gas, then reflected out of the absorption cell by the light outlet and collected by the photodetector; the photodetector 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, which is then sent to the display and alarm module; simultaneously, when the ammonia concentration exceeds a preset threshold, an alarm message is sent to the display and alarm module and the ship's main control room; the display and alarm module is used to display the ammonia concentration information and the alarm message.

[0005] Furthermore, the cyclic sampling system includes a control module, a sampling pump, an outlet pipeline, a sampling pipeline, and a solenoid valve I; several sampling points are connected to the sampling pump's extraction end through their corresponding sampling pipelines, and each sampling pipeline is equipped with a corresponding solenoid valve I. The sampling pump's outlet end is connected to the absorption tank through the outlet pipeline; the control module extracts sample gas from the corresponding sampling point by controlling the opening of the solenoid valve I.

[0006] Furthermore, 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 the solenoid valve II. When the solenoid valve II is open, the sample gas is delivered to the absorption cell. When the solenoid valve II is closed, the sample gas is discharged to the external environment. At least two solenoid valves I are open at the same time. 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 open.

[0007] Furthermore, the gas analysis unit also includes a power module, which converts the external 220V to 24V, 5V and 3.3V to power the laser drive module, signal processing module and sampling control module respectively.

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

[0009] Furthermore, the laser drive module can also drive the laser's TEC controller to control the laser's temperature.

[0010] Compared with existing technologies, the beneficial effects of this utility model are:

[0011] 1. This utility model addresses the shortcomings of existing electrochemical sensors by utilizing laser absorption spectroscopy and multi-point cyclic sampling to achieve online monitoring of multi-point leaks of gases, including ammonia, thereby improving the environmental safety of ammonia-fueled ships and preventing personnel and property losses caused by ammonia leaks.

[0012] 2. In this utility model, at least two sampling pumps simultaneously open a solenoid valve I connected to them, and at most one of the sampling pumps opens a corresponding solenoid valve II. That is, the cyclic sampling system improves the gas replacement efficiency and speeds up the response by pre-sampling.

[0013] 3. This utility model only requires a gas analysis host consisting of a single laser, photoelectric detector and signal processing module. Combined with a cyclic sampling system, it can realize real-time online monitoring of multi-point leaks, with high detection accuracy, fast response, extremely low false alarm rate and high reliability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0016] This utility model provides a marine multi-point ammonia leak monitoring system, such as Figure 1 As shown, the system consists of two parts: an ammonia analyzer and a circulating sampling system. The circulating sampling system is used to circulate and extract sample gas from designated sampling points one by one and deliver it to the ammonia analyzer. The ammonia analyzer includes an absorption cell for receiving sample gas, a laser, a laser driver module, a photodetector, a signal processing module, and a display and alarm module.

[0017] The laser drive module drives and modulates the laser output, enabling it to emit laser light that can be absorbed by ammonia. The laser beam is incident on the absorption cell, reflected multiple times, absorbed by the sample gas, and then reflected out of the absorption cell and onto a photodetector, where it is collected. The photodetector converts the light intensity signal absorbed by the ammonia in the sample gas into a current signal and sends it to the signal processing module. The signal processing module receives the current signal, processes it, and converts it into ammonia concentration information. Specifically, it processes the current signal to obtain a voltage signal related to the ammonia concentration, and uses an internal program to calculate the ammonia concentration in the absorption cell. This ammonia concentration information is then sent to the display and alarm module. Simultaneously, the module also uses an internal program to determine if the concentration exceeds a preset threshold, sending alarm information to the display and alarm module and the ship's main control room. The display and alarm module displays the ammonia concentration information and the alarm message. The ammonia analysis unit uses laser absorption spectroscopy to detect ammonia concentration, offering high accuracy, extremely low false alarm rate, and high reliability.

[0018] The cyclic sampling system includes a control module, a sampling pump, an outlet pipeline, a sampling pipeline, and a solenoid valve I. Several sampling points are connected to the sampling pump's extraction end through their corresponding sampling pipelines. Each sampling pipeline is equipped with a corresponding solenoid valve I. The sampling pump's outlet end is connected to the absorption tank through an outlet pipeline. The control module extracts 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, each with a solenoid valve II on its outlet pipe. The control module also controls the opening and closing of solenoid valve II. When solenoid valve II is open, the extracted sample gas is delivered to the absorption tank; when 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 pipe is opened sequentially according to a predetermined logic, and the sample gas from the designated sampling point is drawn into the ammonia analysis host for detection by the sampling pump. After the sample gas from one sampling point is delivered to the ammonia analysis host, the next sampling point is sampled. Due to the long sampling pipe, it takes a certain amount of time to draw the sample gas from the next sampling point to the outlet pipe, resulting in low sample gas replacement efficiency. Therefore, to improve the sample gas replacement efficiency and speed up the response, the cyclic sampling system uses a pre-sampling method.

[0020] Specifically, the control system ensures that at least two solenoid valves I open simultaneously to extract sample gas. Each open solenoid valve I is connected to a different sampling pump, meaning at least two sampling pumps operate simultaneously, each opening only one solenoid valve I connected to it. This allows at least two sampling pumps to simultaneously extract sample gas from a single sampling point (at least two sampling points are extracted separately). However, at most one sampling pump A has its corresponding solenoid valve IIA open to deliver sample gas A to the absorption tank. The solenoid valves II on the outlet pipes of the remaining sampling pumps are closed, discharging the continuously extracted sample gas into the external environment. After sample gas A is detected, its corresponding solenoid valve IIA is closed, and the solenoid valve IIB of the next sampling pump B, which is currently extracting sample gas B, is opened according to predetermined logic, delivering sample gas B to the absorption tank. Because sample gas B is continuously extracted, it only needs to have solenoid valve IIB opened to enter the absorption tank for detection. Compared to opening solenoid valve IIB only when sample gas B needs to be detected, this significantly reduces the time sample gas B spends in the sampling pipeline, improving sample gas replacement efficiency and accelerating the response speed.

[0021] The ammonia analysis unit also includes a power module, which converts the external 220V voltage to 24V, 5V, and 3.3V voltages to power the laser drive module, signal processing module, and sampling control module, respectively. In practical implementations, this invention can adopt a rack-mount design. For example, the ammonia analysis unit is installed at the top of the rack, the circulating sampling system control module is located at the bottom, and the sampling pipeline, exhaust pipeline, sampling pump, and solenoid valves I and II are arranged on the rear panel; the rack is powered by an external 220V supply.

[0022] The laser can be a 1512nm DFB laser. The laser driving module applies a driving current of superimposed modulation signals to the laser driving terminal, causing the laser to emit laser light of a specified wavelength. The laser driving module can also drive the laser's TEC controller to control the laser's temperature, typically 25°C. The laser output light can be connected to an absorption cell via optical fiber. After absorption by the gas, each laser beam passes through the absorption cell's output port and enters the photodetector. In this embodiment, ammonia leakage is detected. This invention can be used to detect other gases. Simply modulate the laser emitted by the laser to a wavelength absorbable by the gas to be detected, and modify the built-in program in the signal processing module that inverts the voltage signal to obtain the gas concentration accordingly, and other gases can be detected.

[0023] Tests have shown that this invention can quickly and effectively monitor ammonia concentration at multiple locations, with high detection accuracy, short response time, immunity to interference from other gases, and long service life, making it highly suitable for ammonia leak monitoring in the shipbuilding industry.

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

Claims

1. A marine multi-point ammonia leak monitoring system, characterized in that, It consists of a gas analyzer and a cyclic sampling system; the cyclic sampling system is used to cyclically and sequentially extract sample gas from several designated sampling points and deliver it to the gas analyzer; the gas analyzer includes an absorption cell for receiving sample gas, a laser, a laser driver module, a photodetector, a signal processing module, and a display and alarm module; The laser drive module is used to drive and modulate the laser output. The laser light 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 by the light outlet and collected by the photodetector. The photodetector is used to convert the light intensity signal into a current signal. The signal processing module is used to receive the current signal, process it, and convert it into ammonia concentration information, which is then sent to the display and alarm module. At the same time, when the internal threshold is exceeded, alarm information is sent to the display and alarm module and the ship's main control room. The display and alarm module is used to display the ammonia concentration information and alarm information.

2. The marine multi-point ammonia leak monitoring system as described in claim 1, characterized in that, The cyclic sampling system includes a control module, a sampling pump, an outlet pipeline, a sampling pipeline, and a solenoid valve I. Several sampling points are connected to the sampling pump's extraction end through their corresponding sampling pipelines. Each sampling pipeline is equipped with a corresponding solenoid valve I. The sampling pump's outlet end is connected to the absorption tank through an outlet pipeline. The control module extracts sample gas from the corresponding sampling point by controlling the opening of the solenoid valve I.

3. The marine multi-point ammonia leak monitoring system as described in 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 open, the sample gas is delivered to the absorption cell. When solenoid valve II is closed, the sample gas is discharged to the external environment. At least two solenoid valves I are open at the same time. 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 open.

4. The marine multi-point ammonia leak monitoring system as described in claim 1, characterized in that, The gas analysis unit also includes a power module, which converts the external 220V to 24V, 5V and 3.3V to power the laser drive module, signal processing module and sampling control module respectively.

5. The marine multi-point ammonia leak monitoring system as described in any one of claims 1-4, characterized in that, The laser is a 1512nm DFB laser. The laser driving module applies a driving current of superimposed modulation signal to the laser driving end, so that the laser emits laser light that can be absorbed by the gas to be detected.

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

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