CN204986398U - LNG storage tank - Google Patents

Abstract

The utility model discloses an LNG storage tank, which comprises a tank body, an overflow pipe drawn from the tank body, an overflow barrel connected with the overflow pipe, and an overflow barrel installed on the overflow barrel. temperature control device, the overflow pipe is set at the overflow port of the tank, when the LNG liquid in the tank is filled to the highest liquid level of the tank, the LNG liquid in the tank passes through the The overflow pipe flows into the overflow cylinder, the temperature control device detects the temperature in the overflow cylinder, and when the detected temperature is lower than the set value, the temperature control device automatically alarms. The LNG storage tank of the utility model can automatically monitor whether the LNG storage tank is full.

Description

LNG storage tank

technical field

The utility model relates to the field of natural gas storage and transportation, in particular to an LNG storage tank.

Background technique

At present, ships in my country's inland waters are basically powered by diesel engines. In the field of inland shipping fuel consumption, the price fluctuations of traditional diesel and other energy products remain high on the one hand, leading to rising transportation costs for shipping companies; It is in line with the country's energy development strategy of developing a low-carbon green economy, saving energy and reducing emissions to achieve sustainable development. The use of liquefied natural gas (LNG) clean energy saves 55% to 60% of the cost compared with diesel oil. While greatly reducing the operating costs of shipping companies, more importantly, it can reduce environmental pollution, which has very obvious social and economic benefits.

In the process of promoting the application of LNG fuel on water, marine LNG storage tanks are basically used to store LNG fuel safely. There are many essential differences between marine LNG storage tanks and common land LNG storage tanks. Among them, in the process of filling the storage tank, there is a completely different judgment on whether the LNG is full: the land-use LNG storage tank can judge whether the LNG storage tank has reached the full level by observing whether there is liquid flowing out from the outlet of the overflow pipe, while This method cannot be used for marine LNG storage tanks. The main reasons are: 1. The main body of the ship is made of non-low temperature resistant materials. If the cryogenic LNG overflows on the deck of the hull, it is easy to cause the deck to crack under the impact load; 2. The area where the storage tank is placed is usually close to the living area of the ship. When the cryogenic LNG is discharged, due to the low temperature of the LNG, it sinks and floats on the deck surface. If it encounters an open flame, it is easy to cause a cloud fire, affecting the safety of life and property and the overall safety of the ship.

At the same time, CCS (China Classification Society) "Code for Natural Gas Fueled Ships" (2013) has a mandatory requirement that the rated filling rate of marine LNG storage tanks should not exceed 90%. Monitoring and alarming is particularly critical.

Utility model content

The purpose of the utility model is to solve the technical problems of potential safety hazards and easy damage to the hull deck of the liquid level monitoring of the marine LNG storage tank in the prior art, and provide an LNG storage tank capable of safely monitoring the liquid level of the LNG storage tank.

The utility model proposes an LNG storage tank, which includes a tank body, an overflow pipe drawn from the tank body, an overflow tube connected with the overflow tube, and an overflow tube installed on the overflow tube. The temperature control device, the overflow pipe is arranged at the overflow port of the tank body, when the LNG liquid in the tank body is filled to the highest liquid level of the tank body, the liquefied natural gas in the tank body passes through the The overflow pipe flows into the overflow cylinder, the temperature control device detects the temperature in the overflow cylinder, and when the detected temperature is lower than the set value, the temperature control device automatically alarms.

As for the LNG storage tank, the LNG storage tank further includes a vent pipe arranged on the top of the overflow tube and communicating with the overflow tube.

In the LNG storage tank, the temperature control device includes a temperature sensor and an alarm device, the temperature sensor is electrically connected to the alarm device, and when the temperature detected by the temperature sensor is lower than the set value, the alarm device automatically alarms .

The LNG storage tank, the LNG storage tank also includes a controller and a solenoid valve arranged on the tank filling main pipe valve, the temperature control device includes a temperature sensor and an alarm device, the solenoid valve, the The temperature sensor and the alarm device are respectively electrically connected to the controller. When the liquefied natural gas flows into the overflow cylinder, the temperature sensor feeds back an electrical signal to the controller, and the controller communicates the electrical signal with the device. Compared with the set value, if it is less than the set value, the controller will automatically send a signal to the alarm device, and at the same time cut off the power to the electromagnetic valve on the valve of the filling main pipe to stop the filling of liquefied natural gas.

In the LNG storage tank, the controller is a PLC controller.

In the LNG storage tank, the tank body includes an inner tank body and an outer tank body, the overflow pipe includes an overflow pipe inside the tank and an overflow pipe outside the tank, and the overflow port of the tank body is arranged in the inner tank body. On the tank body, one end of the overflow pipe in the tank is connected to the overflow port of the inner tank body and communicated with the inner tank body, and the other end of the overflow pipe in the tank body is arranged on the outer tank body The double-sided joint at the place is connected to one end of the overflow pipe outside the tank, and the other end of the overflow pipe outside the tank is connected to the overflow cylinder.

In the LNG storage tank, the overflow cylinder includes a circular pipe and a sealing plate for sealing the circular pipe.

In the LNG storage tank, the temperature control device is installed on the sealing plate.

In the LNG storage tank, the overflow cylinder, temperature control device, and vent pipe are placed in a box.

In the LNG storage tank, the overflow barrel is a stainless steel overflow barrel.

Compared with the prior art, the utility model has the following beneficial effects:

In the LNG storage tank of the present invention, the LNG liquid in the tank is introduced into the overflow cylinder through the overflow pipe, and a temperature control device is installed in the overflow cylinder. When the temperature control device detects that the temperature in the overflow cylinder is lower than the set value , the temperature control device automatically alarms, thereby realizing automatic monitoring and alarming of the full liquid level of the LNG storage tank. In addition, if the LNG storage tank is placed on the hull, the overflow tube can also prevent the liquid flowing out from the overflow pipe from contacting the deck of the hull to protect the deck.

Description of drawings

Fig. 1 is a schematic structural view of the LNG storage tank of the present invention.

detailed description

In order to further illustrate the principle and structure of the utility model, the preferred embodiments of the utility model will be described in detail in conjunction with the accompanying drawings.

LNG storage tanks are mainly used to contain cryogenic liquefied natural gas and keep the liquefied natural gas cold to prevent it from vaporizing. During the filling process of the LNG storage tank, in order to judge whether the storage tank is full or not, generally, an overflow pipe is set at the overflow height position (the highest liquid level) of the tank body, and the overflow pipe extends from the tank body to the outside of the tank.

The utility model provides an LNG storage tank which can be placed on the hull of a ship or marine engineering equipment, and the LNG storage tank can automatically and safely monitor whether the LNG storage tank is full.

As shown in Figure 1, the LNG storage tank 10 of the present utility model includes a tank body 11, an overflow pipe drawn from the tank body 11, an overflow tube 13 communicated with the overflow tube, and an overflow tube 13 installed on the overflow tube 13. The upper temperature control device 14.

The tank body 11 includes an inner tank body 111 and an outer tank body 112, and a heat insulating material is filled between the inner tank body 111 and the outer tank body 112. The inner tank 111 is used to fill the LNG liquid, but because the LNG liquid is easy to gasify and the LNG liquid will slosh in the tank, the inner tank 111 cannot be filled, and generally it is only filled to 90% of the volume of the inner tank 111. %. The inner tank body 111 is provided with an overflow port at the highest liquid level 20, and the overflow pipe is connected to the inner tank body 111 through the overflow port and communicates with the inner space of the inner tank body 111, so that when the LNG liquid is filled When reaching the highest liquid level 20 of the inner tank body 111, the LNG liquid flows into the overflow pipe.

The overflow pipe includes an overflow pipe in the tank (not shown in the figure, Figure 1 only shows the flow direction of the liquid in the overflow pipe in the tank) and an overflow pipe 12 outside the tank, one end of the overflow pipe in the tank is connected to the inner tank body The overflow port of 111 is in communication with the inner tank body 111, and the other end of the overflow pipe in the tank is connected with one end of the overflow pipe 12 outside the tank through a double-sided joint arranged at the outer tank body 112.

The other end of the overflow pipe 12 outside the tank is connected to the overflow barrel 13 . The overflow barrel 13 includes a round tube 131 and a sealing plate 132 for closing the round tube 131 and located at the top of the round tube 131 . The overflow barrel 13 can be a stainless steel overflow barrel.

The LNG liquid in the inner tank body 111 and part of the low-temperature gas gasified from the LNG liquid flow into the overflow cylinder through the overflow pipe.

The temperature control device 14 is arranged on the top of the overflow cylinder 13, and it includes a temperature sensor and an alarm device, and the temperature sensor is electrically connected with the alarm device. The temperature sensor is used to detect the temperature in the overflow cylinder 13, and convert the detected temperature value into an electrical signal. When the temperature detected by the temperature sensor is lower than the set value, the alarm device will automatically alarm.

The LNG storage tank 10 also includes a vent pipe 15 arranged on the top of the overflow barrel 13 and communicating with the overflow barrel 13 . The vent pipe 15 is used to vaporize the liquid in the overflow tube 13 and discharge it into the atmosphere.

Further, the LNG storage tank also includes a controller and a solenoid valve arranged on the valve of the tank filling main pipe, and the solenoid valve, temperature sensor and alarm device are respectively electrically connected to the controller. The controller may be a PLC controller (Programmable Logic Controller).

When the liquefied natural gas flows into the overflow cylinder 13, when the temperature sensor senses that the temperature value of the overflow cylinder 13 is lower than the predetermined temperature value, the temperature sensor converts the temperature value into an electrical signal, and feeds back the electrical signal to the control The controller compares the electrical signal with the set value, if it is less than the set value, the controller sends an electrical signal to the alarm device, the alarm device alarms, and at the same time the controller cuts off the electromagnetic valve on the valve of the filling main pipe. Electricity, stop the filling of liquefied natural gas.

As mentioned above, the alarm device can alarm automatically, and also can alarm after a signal is given by the controller.

In addition, the above-mentioned overflow cylinder, temperature control device, and vent pipe can be placed in a box, and the box can be directly placed on the hull.

The process that the LNG storage tank of the present utility model is used to monitor the liquid level of the storage tank is as follows:

During the filling process of the LNG storage tank, if the cryogenic LNG liquid does not reach the maximum liquid level of the tank, the low-temperature gas vaporized from part of the cryogenic LNG liquid will be introduced into the overflow cylinder from the overflow pipe, and the temperature control device will The temperature is fed back by electrical signal, and the PLC controller compares the feedback electrical signal with the set value (the set value is set according to the temperature of the cryogenic LNG liquid). If it is greater than the set value, the PLC controller does not take any action. Action; if the cryogenic LNG liquid reaches the highest liquid level in the tank, the cryogenic LNG liquid flows into the overflow cylinder from the overflow pipe, the temperature control device feeds back the current signal according to the temperature signal, and the PLC controller according to the feedback current signal and the set value For comparison, it should be less than the set value at this time, the PLC controller sends a signal to the alarm device, and at the same time cuts off the power to the solenoid valve on the valve of the filling main pipe to stop the filling of LNG liquid.

The low-temperature gas in the overflow tank and the vaporized low-temperature gas of the cryogenic LNG liquid are discharged into the atmosphere in the safe area through the vent pipe, so as to realize automatic monitoring and alarm of the full liquid level of the LNG storage tank.

To sum up, in the LNG storage tank of the present invention, the LNG liquid in the tank is introduced into the overflow cylinder through the overflow pipe, and a temperature control device is installed in the overflow cylinder. When the temperature control device detects that the temperature in the overflow cylinder is lower than When the value is set, the temperature control device will automatically alarm, thereby realizing the automatic monitoring and alarm of the full liquid level of the LNG storage tank. In addition, if the LNG storage tank is placed on the hull, the overflow tube can also prevent the liquid flowing out from the overflow pipe from contacting the deck of the hull to protect the deck.

In addition, the LNG storage tank is also equipped with a vent pipe on the overflow tube to discharge the low-temperature gas flowing into the overflow tube and the gasified cryogenic LNG liquid into the atmosphere of the safe area through the vent tube , to ensure the safety of personnel and property around the LNG storage tank.

The above are only preferred feasible embodiments of the present utility model, and do not limit the protection scope of the present utility model. All equivalent structural changes made by using the description of the utility model and the contents of the accompanying drawings are included in the protection scope of the present utility model. .

Claims (10)

1. A kind of LNG storage tank, is characterized in that, comprises a tank body, the overflow pipe that draws from described tank body, the overflow tube that communicates with described overflow tube and is installed on the described overflow tube The temperature control device, the overflow pipe is arranged at the overflow port of the tank body, when the LNG liquid in the tank body is filled to the highest liquid level of the tank body, the liquefied natural gas in the tank body passes through the The overflow pipe flows into the overflow cylinder, the temperature control device detects the temperature in the overflow cylinder, and when the detected temperature is lower than the set value, the temperature control device automatically alarms. 2 . The LNG storage tank according to claim 1 , characterized in that, the LNG storage tank further comprises a vent pipe arranged at the top of the overflow tube and communicating with the overflow tube. 3 . 3. The LNG storage tank according to claim 1, wherein the temperature control device comprises a temperature sensor and an alarm device, the temperature sensor is electrically connected to the alarm device, and when the temperature detected by the temperature sensor is lower than the set When the value is set, the alarm device will automatically alarm. 4. The LNG storage tank according to claim 1, characterized in that, the LNG storage tank also includes a controller and a solenoid valve arranged on the filling manifold valve of the tank body, and the temperature control device includes A temperature sensor and an alarm device, the solenoid valve, the temperature sensor and the alarm device are respectively electrically connected to the controller, and when the liquefied natural gas flows into the overflow cylinder, the temperature sensor feeds back an electrical signal to the A controller, the controller compares the electrical signal with the set value, if it is less than the set value, the controller automatically sends a signal to the alarm device, and at the same time cuts off the power to the solenoid valve on the filling main pipe valve, Stop LNG filling. 5. The LNG storage tank according to claim 4, wherein the controller is a PLC controller. 6. The LNG storage tank according to claim 1, wherein the tank body comprises an inner tank body and an outer tank body, and the overflow pipe comprises a tank inner overflow pipe and a tank outer overflow pipe, and the tank body The overflow port of the body is arranged on the inner tank body, and one end of the overflow pipe in the tank is connected with the overflow port of the inner tank body and communicated with the inner tank body, and the overflow pipe in the tank body The other end is connected to one end of the overflow pipe outside the tank through a double-sided joint arranged at the outer tank body, and the other end of the overflow pipe outside the tank is connected to the overflow cylinder. 7. The LNG storage tank according to claim 1, wherein the overflow tube comprises a round pipe and a sealing plate for closing the round pipe. 8. The LNG storage tank according to claim 7, wherein the temperature control device is installed on the sealing plate. 9. The LNG storage tank according to claim 1, wherein the overflow cylinder, the temperature control device and the vent pipe are placed in a tank. 10. The LNG storage tank according to claim 1, wherein the overflow barrel is a stainless steel overflow barrel.