CN106287203A - A kind of novel double fluid gauge LNG filling machine - Google Patents

Abstract

The invention provides a novel double-flow meter LNG filling machine, which is used for filling LNG from an LNG storage tank into an LNG gas storage container; it includes a liquid phase flow meter, a control valve, and a liquid filling gun connected in sequence; the liquid phase The input end of the flowmeter is connected with the LNG storage tank, and the output end of the liquid filling gun is connected with the LNG gas storage container; it also includes an air return gun and a gas phase flowmeter connected in sequence, and the input end of the air return gun is connected with the LNG gas storage container, The output end of the gas phase flowmeter is connected with the LNG storage tank; it also includes an electronic meter controller for controlling the gas filling process and calculating the flow rate, and the electronic meter controller is respectively connected with the LNG storage tank, the liquid phase flowmeter, the gas phase flowmeter, Control valve signal connection. The novel double-flow meter LNG refueling machine of the present invention can realize the residual gas recovery of the LNG gas storage container, and realize the metering function of the residual gas return volume through the gas ultrasonic flowmeter, thereby not only reducing the internal pressure of the LNG gas storage container, but also ensuring that the LNG It can be filled smoothly, and can improve the filling and metering accuracy of the LNG dispenser.

Description

A New Double Flow Meter LNG Dispenser

technical field

The invention relates to the technical field of gas dispensers, and more specifically relates to a novel double-flow meter LNG gas dispenser.

Background technique

With the continuous development of my country's LNG automobile industry, the number of LNG filling stations continues to increase, and the technology and application of LNG filling machines are also developing at a high speed. The market demand is increasing, and the requirements for the performance of LNG filling machines are getting higher and higher.

When working, the liquid filling gun of the LNG dispenser is inserted into the liquid inlet of the vehicle-mounted LNG gas storage cylinder, so that the LNG liquid flows from the liquid inlet pipe of the gas dispenser to the liquid filling gun, and then enters the vehicle-mounted LNG gas storage cylinder. At this time, the vaporized LNG vapor in the vehicle-mounted LNG storage cylinder makes the internal pressure high, which will not only greatly affect the smoothness of LNG filling, but also affect the metering accuracy of the LNG filling machine. Therefore, how to improve the filling metering accuracy of the LNG filling machine is an important topic in the research of the LNG filling industry at this stage.

In addition, LNG is liquefied natural gas, which is obtained by compressing and heating up natural gas after purification, cooling and removing heat under the action of mixed refrigerant, and then throttling and expanding. The temperature at normal pressure is -162°C; The liquefied product is cooled at an ultra-low temperature, so it is easily vaporized when heated. Therefore, in order to prevent LNG gasification is also an important problem that needs to be solved at this stage.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies in the prior art, and provide a novel double-flow meter LNG dispenser, which can realize the function of recovering and measuring the residual gas of the LNG gas storage container, thereby not only reducing the The internal pressure of the LNG gas storage container ensures the smooth filling of LNG, and can improve the filling and metering accuracy of the LNG gas dispenser.

In order to achieve the above object, the present invention is achieved through the following technical solutions: a novel dual-flowmeter LNG filling machine, which is used to fill the LNG of the LNG storage tank to the LNG gas storage container; it is characterized in that: it includes sequentially connected A liquid phase flowmeter, a control valve and a filling gun; the input end of the liquid phase flowmeter is connected to the LNG storage tank, and the output end of the liquid filling gun is connected to the LNG gas storage container; it also includes a sequentially connected air return gun and a gas phase flow rate meter, the input end of the air return gun is connected with the LNG gas storage container, and the output end of the gas phase flowmeter is connected with the LNG storage tank; it also includes an electronic meter controller for controlling the gas filling process and calculating the flow rate, and the electronic meter controls The devices are respectively connected to the LNG storage tank, the liquid phase flowmeter, the gas phase flowmeter and the control valve for signal connection.

In the above scheme, the present invention connects the LNG gas storage container and the LNG storage tank through the air return gun and the gas phase flowmeter respectively, and then forms a return flow channel, so that the residual gas of the LNG gas storage container flows back to the LNG storage tank, realizing LNG gas storage The residual gas in the container is recovered, thereby reducing the pressure inside the LNG gas storage container and ensuring the smooth filling of LNG. At the same time, the return gas volume of the residual gas in the LNG gas storage container can be obtained by measuring the gas phase flowmeter. During the gas filling process, the electronic controller of the gas dispenser automatically controls the gas filling process, and calculates according to the flow signals output by the liquid phase flowmeter and the gas phase flowmeter. It is the difference between the measurement value of the liquid phase flowmeter and the measurement value of the gas phase flowmeter. Compared with the traditional gas filling machine, which only measures the amount of liquid added as the filling amount of the gas filling machine, the present invention sets a gas phase flowmeter connected to the signal of the electronic controller, and uses the difference between the amount of liquid added and the amount of returned gas as the LNG filling amount. Filling volume of the gas dispenser, which will make the metering accuracy of the gas dispenser more accurate.

The liquid phase flowmeter is a Coriolis mass flowmeter.

The gas phase flowmeter is a gas ultrasonic flowmeter. The invention uses a gas ultrasonic flowmeter. From the perspective of performance, its measurement accuracy is not affected by the temperature, pressure, density and viscosity of the measured fluid. It has good long-term precision stability, flexible use, long life, and convenient maintenance. Etc. Moreover, it can fully meet the requirements of LNG dispenser return gas metering. From an economic point of view, its price and cost are extremely low compared to other flowmeters, which is extremely important for the localization of LNG dispensers.

The present invention also includes an internal precooling circuit; the internal precooling circuit is sequentially connected by an LNG storage tank, a liquid phase flow meter and a control valve, and the output end of the control valve is connected with the LNG storage tank to form.

The present invention also includes an external precooling circuit; the external precooling circuit is sequentially connected by an LNG storage tank, a liquid phase flow meter, a control valve and a filling gun, and the output end of the filling gun is connected with the LNG storage tank to form.

The present invention realizes the pre-cooling cycle of the gas dispenser through the internal pre-cooling circuit and the external pre-cooling circuit: in order to adjust the temperature of the pipeline of the gas dispenser system (when the gas dispenser is not working, the temperature of the system pipeline can be regarded as normal temperature) Reduced, when the internal pipeline of the dispenser is filled with liquid and the relevant state parameters meet the cooling requirements (pipeline temperature reaches minus 120°C), the precooling ends (the entire precooling time is about 2 to 3 minutes), so that the vaporization of the LNG medium can be avoided , to prevent the occurrence of gas-liquid two-phase flow. During the whole pre-cooling stage, the liquid flow meter of the dispenser does not measure.

The control valve is a cryogenic pneumatic emergency cut-off valve.

The pipeline between the LNG storage tank and the liquid phase flowmeter is provided with a release device; the release device is composed of a stop valve V1, a safety valve SV1, a pressure gauge PG, a pressure sensor P and peripheral pipeline connections; the pressure gauge PG and the pressure sensor P are connected to the pipeline between the LNG storage tank and the liquid phase flowmeter. If the pipeline pressure is too high, the excess pressure can be released through the release device.

A safety valve is arranged between the LNG storage tank and the gas phase flowmeter.

The invention also includes an auxiliary device with preset and printing functions; the auxiliary device is connected with the electronic counter for signal.

The novel dual-flow meter LNG dispenser of the present invention works like this:

1. Insert the filling gun of the LNG dispenser into the large circulation nozzle of the LNG dispenser, press the "pre-cooling" key on the keyboard of the dispenser, and the dispenser starts to pre-cool. The LNG liquid internal pre-cooling circuit and external pre-cooling circuit return to the LNG storage tank. When the internal pipeline of the gas dispenser is filled with liquid and the relevant state parameters meet the cooling requirements, the pre-cooling ends. The gas dispenser does not measure at this stage.

2. After the pre-cooling is over, insert the liquid filling gun of the LNG dispenser into the liquid inlet of the vehicle-mounted LNG gas storage container, insert the return gun into the gas return port of the LNG gas storage container, and press the "Refill" button on the keyboard of the LNG dispenser , the dispenser starts filling. The LNG liquid flows from the liquid inlet pipe of the dispenser to the liquid phase flowmeter, control valve and liquid filling gun, and then enters the vehicle-mounted LNG gas storage container; the vaporized LNG vaporized gas in the vehicle-mounted LNG gas storage container passes through the air return gun and gas phase flowmeter And the return gas pipeline returns to the LNG storage tank. The filling amount of the LNG gas dispenser is the difference between the measured values of the liquid phase flowmeter and the gas phase flowmeter, and the gas dispenser will automatically calculate and display the difference. When the vehicle LNG gas storage cylinder is filled with LNG, the gas filling machine will automatically stop (it can also be manually stopped in advance or fixed gas filling).

3. After the LNG dispenser stops, remove the return air gun from the vehicle-mounted LNG gas storage container, then remove the liquid filling gun, insert the liquid filling gun into the liquid filling gun seat of the LNG dispenser, and complete the gas filling.

During the entire gas filling process, the liquid phase flowmeter and gas phase flowmeter measure the physical signals of the fluid density and quality flowing through the LNG gas dispenser, which are converted into electrical pulse signals by the signal converter and sent to the electronic meter controller. The pressure sensor and pressure gauge on the LNG dispenser can transmit the working status of the LNG dispenser to the server of the LNG refueling station, so that it can monitor the entire refueling process and complete the refueling work automatically.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. The new double-flow meter LNG filling machine of the present invention can realize the recovery of residual gas in the LNG gas storage container, and realize the measurement function of the residual gas return volume through the gas ultrasonic flowmeter, thereby not only reducing the internal pressure of the LNG gas storage container, It can ensure the smooth filling of LNG, and can improve the filling and metering accuracy of the LNG dispenser. At the same time, its price and cost are extremely low compared with other flow meters.

2. The present invention realizes the pre-cooling cycle of the dispenser through the internal pre-cooling circuit and the external pre-cooling circuit, thereby avoiding the vaporization of the LNG medium and preventing the occurrence of gas-liquid two-phase flow.

Description of drawings

Fig. 1 is the working flow chart of novel double flow meter LNG dispenser of the present invention;

Fig. 2 is a working principle diagram of the novel double-flowmeter LNG dispenser of the present invention;

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example

As shown in Fig. 1 and Fig. 2, the novel double-flow meter LNG filling machine of the present invention is used to fill the LNG of the LNG storage tank to the LNG gas storage container, and the LNG filling machine includes liquid phase flow rates connected in sequence Meter, low temperature pneumatic emergency shut-off valve as control valve, liquid filling hose and liquid filling gun, return air gun, return air hose and gas phase flowmeter connected in sequence, and electronic meter controller for controlling the filling process and calculating the flow rate Wherein, the input end of the liquid phase flowmeter is connected with the LNG storage tank, the output end of the liquid filling gun is connected with the LNG gas storage container, the input end of the air return gun is connected with the LNG gas storage container, and the output end of the gas phase flowmeter is connected with the LNG storage tank. The tank is connected, and the electronic meter controller is respectively connected with the LNG storage tank, the liquid phase flow meter, the gas phase flow meter, and the control valve signal.

The liquid phase flowmeter of the present invention is a Coriolis mass flowmeter, and the gas phase flowmeter is a gas ultrasonic flowmeter. The invention uses a gas ultrasonic flowmeter. From the perspective of performance, its measurement accuracy is not affected by the temperature, pressure, density and viscosity of the measured fluid. It has good long-term precision stability, flexible use, long life, and convenient maintenance. Etc. Moreover, it can fully meet the requirements of LNG dispenser return gas metering. From an economic point of view, its price and cost are extremely low compared to other flowmeters, which is extremely important for the localization of LNG dispensers.

The present invention also includes an internal precooling circuit and an external precooling circuit, wherein the internal precooling circuit is sequentially connected by an LNG storage tank, a liquid phase flowmeter and a control valve, and the output end of the control valve is connected to the LNG storage tank to form. The external pre-cooling circuit is connected in sequence by the LNG storage tank, liquid phase flow meter, control valve, liquid filling hose and liquid filling gun, and the output end of the liquid filling gun is connected to the LNG storage tank to form. The present invention realizes the pre-cooling cycle of the gas dispenser through the internal pre-cooling circuit and the external pre-cooling circuit: in order to adjust the temperature of the pipeline of the gas dispenser system (when the gas dispenser is not working, the temperature of the system pipeline can be regarded as normal temperature) Reduced, when the internal pipeline of the dispenser is filled with liquid and the relevant state parameters meet the cooling requirements (pipeline temperature reaches minus 120°C), the precooling ends (the entire precooling time is about 2 to 3 minutes), so that the vaporization of the LNG medium can be avoided , to prevent the occurrence of gas-liquid two-phase flow. During the whole pre-cooling stage, the liquid flow meter of the dispenser does not measure.

The pipeline between the LNG storage tank and the liquid phase flowmeter of the present invention is provided with a release device, and the release device is composed of a stop valve V1, a safety valve SV1, a pressure gauge PG, a pressure sensor P and peripheral pipeline connections, wherein the pressure gauge PG and the pressure sensor P are connected to the pipeline between the LNG storage tank and the liquid phase flowmeter. If the pipeline pressure is too high, the excess pressure can be released through the release device. A safety valve is provided between the LNG storage tank and the gas phase flowmeter.

The present invention also includes an auxiliary device with preset and printing functions, and the auxiliary device is connected with the electronic counter for signal.

The novel dual-flow meter LNG dispenser of the present invention works like this:

1. Insert the filling gun of the LNG dispenser into the large circulation nozzle of the LNG dispenser, press the "pre-cooling" key on the keyboard of the dispenser, and the dispenser starts to pre-cool. The LNG liquid internal pre-cooling circuit and external pre-cooling circuit return to the LNG storage tank. When the internal pipeline of the gas dispenser is filled with liquid and the relevant state parameters meet the cooling requirements, the pre-cooling ends. The gas dispenser does not measure at this stage.

2. After the pre-cooling is over, insert the liquid filling gun of the LNG dispenser into the liquid inlet of the vehicle-mounted LNG gas storage container, insert the return gun into the gas return port of the LNG gas storage container, and press the "Refill" button on the keyboard of the LNG dispenser , the dispenser starts filling. The LNG liquid flows from the liquid inlet pipe of the gas dispenser to the liquid phase flowmeter M1, the control valve GV1, the liquid filling hose and the liquid filling gun LN, and then enters the vehicle-mounted LNG gas storage container; the gasified LNG in the vehicle-mounted LNG gas storage container evaporates The gas returns to the LNG storage tank through the gas return gun GN, the gas return hose, the gas phase flowmeter M2 and the gas return pipeline. The filling amount of the LNG dispenser is the difference between the measured values of the liquid phase flowmeter M1 and the gas phase flowmeter M2, and the gas dispenser will automatically calculate and display the difference. When the vehicle LNG gas storage cylinder is filled with LNG, the gas filling machine will automatically stop (it can also be manually stopped in advance or fixed gas filling).

3. After the LNG dispenser stops, remove the return air gun GN from the vehicle-mounted LNG gas storage container, then remove the liquid filling gun LN, insert the liquid filling gun LN into the liquid filling gun seat LNK of the LNG dispenser, and complete the filling.

During the entire gas filling process, the liquid phase flowmeter M1 and the gas phase flowmeter M2 measure the physical signals of the fluid density and quality flowing through the LNG gas dispenser, which are converted into electrical pulse signals by the signal converter and sent to the electronic meter for control. The pressure sensor P and pressure gauge PG on the LNG filling machine can transmit the working status of the LNG filling machine to the LNG filling station server, so that it can monitor the entire filling process and automatically complete the filling work.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (9)

1. a novel double fluid gauge LNG filling machine, for filling the LNG of LNG storage tank to LNG air container；Its feature exists In: include liquid phase stream gauge, control valve and the liquid feeding rifle being sequentially connected with；The input of described liquid phase stream gauge is with LNG storage tank even Connecing, the outfan of liquid feeding rifle is connected with LNG air container；Also include the gentle multi-phase flowmeter of return-air rifle being sequentially connected with, described time The input of air gun is connected with LNG air container, and the outfan of gas phase flow rate meter is connected with LNG storage tank；Also include for controlling The electrometer controller of fueling process calculated flow rate, described electrometer controller respectively with LNG storage tank, liquid phase stream gauge, gas Multi-phase flowmeter, control valve signal connect.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: described liquid phase stream amount is calculated as section Li Aoli mass flowmenter.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: described gas phase flow rate is calculated as gas Body ultrasonic flowmeter.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: also include internal pre-cold loop； The pre-cold loop in described inside is sequentially connected with by LNG storage tank, liquid phase stream gauge and control valve, and control valve outfan stores up with LNG Tank connects formation.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: also include outside pre-cold loop； The pre-cold loop in described outside is sequentially connected with by LNG storage tank, liquid phase stream gauge, control valve and liquid feeding rifle, and the output of liquid feeding rifle End is connected formation with LNG storage tank.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: described control valve is low wet Dynamic quick action emergency valve.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: described LNG storage tank and liquid phase stream Pipeline between gauge is provided with bleeding device；Described bleeding device is passed by stop valve V1, relief valve SV1, Pressure gauge PG, pressure Sensor P and peripheral conduits connect composition；Described Pressure gauge PG and pressure transducer P all with LNG storage tank and liquid phase stream gauge it Between pipeline connect.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: described LNG storage tank and gas phase stream Relief valve it is provided with between gauge.

Novel double fluid gauge LNG filling machine the most according to claim 1, it is characterised in that: also include having preset and beat The auxiliary device of print function；Described auxiliary device is connected with electronics controlling device signal.