RU2358188C2 - Method for delivery of liquid cryo-product and device for its realisation - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: method for delivery of liquid product to consumer includes chilling and start-up of centrifugal pump, attainment of nominal autonomous mode of operation, flow bypassing downstream pump into cryogenic reservoir. Transfer to mode of delivery to consumer is realised by smooth reduction of bypassed flow and with preservation of rated pressure downstream pump. Flow of cryo-product downstream centrifugal pump is separated into controlled and uncontrolled flow, which makes from 70% to 80% of rated pump flow in range of back pressure downstream pump from supercharging pressure in cryogenic reservoir to 0.95 from rated discharge downstream pump. After chilling and start-up of pump uncontrolled flow is disconnected. Attainment of autonomous mode is executed only by flow rate of uncontrolled flow. Transfer to mode of liquid product delivery to consumer is carried out in two stages. At the first stage all flow rate of uncontrolled flow is changed over. At the second stage flow rate is increased to rated value by addition of controlled flow rate, keeping rated discharge downstream pump. Device comprises cryogenic reservoir, evaporator of supercharge, centrifugal pump, pipeline of liquid flow from reservoir to pump, pipeline of liquid delivery from pump and bypass pipeline, which connects delivery pipeline with cryogenic reservoir. On delivery pipeline to place of its connection with bypass pipeline, narrowing device is arranged in the form nozzle block with control valve connected parallel to narrowing device.

EFFECT: provision of stationary and stable operation.

2 cl, 1 dwg

Description

The invention relates to cryogenic technology and can be widely used in stationary and transport systems for filling with liquid nitrogen, oxygen and argon.

A known method and device for issuing a liquid cryogenic product by evaporation and pressurization of a part of a liquid cryogenic product taken from a vessel into a gas cryogenic container (see. Epifanova V.I. et al. “Separation of air by deep cooling”, volume 2, p. 433, fig. .Р17, Moscow, "Engineering", 1977).

The disadvantages of this method and device are the need to manufacture and operate cryogenic high-pressure equipment in the case of issuing a cryogenic product at a pressure of 1.5 MPa and above, reducing the amount of liquid cryogenic product to the consumer due to the selection of a part of the liquid product to organize pressurization under high pressure.

The closest in technical essence and the achieved effect to the claimed invention is a method and device for dispensing a liquid cryogenic product, including cooling the pump under the influence of the height of the liquid column in the cryogenic tank, starting the pump and reaching the nominal autonomous mode of operation, bypassing the flow after the pump to the cryogenic tank, transition on the regime of issuing to the consumer by increasing the flow to the consumer, maintaining the nominal regime of issuing liquid cryoproduct to the consumer by adjusting the total flow rate, Vai consumer [cm. Patent RU 2027946 C1, F17C 6/00].

The disadvantages of this method and device are the need to install valves on the bypass and product delivery pipelines to the consumer with an accurate control characteristic, the possibility of disrupting the pump mode up to a stop, especially during start-up or changing parameters during delivery to the consumer.

The task to be solved is to ensure stable and stable operation of the dispensing system in all modes due to the simplicity and reliability of starting the pump and its subsequent transfer to the dispensing mode of liquid cryoproduct to the consumer.

The specified technical result is achieved by the fact that in the method of dispensing a liquid product to a consumer, including cooling the pump under the influence of the height of the liquid column in the cryogenic tank, starting the pump and reaching the rated autonomous mode of operation, bypassing the flow after the pump to the cryogenic tank, switching to the dispensing mode by increasing flow to the consumer, maintaining the nominal regime of issuing liquid cryoproduct to the consumer by adjusting the total flow issued to the consumer, use centrifugal os, switching to the consumer delivery mode is also carried out by smoothly decreasing the bypassed flow and maintaining the nominal pressure behind the pump, the cryoproduct flow after the centrifugal pump is divided into an adjustable and unregulated flow, comprising from 70% to 80% of the nominal pump flow in the backpressure range from the pump to pressure pressurization in a cryogenic tank up to 0.95 of the nominal pressure behind the pump, and after cooling and starting the pump, the regulated flow is turned off, the output to autonomous mode is performed exclusively by the flow rate of the unregulated flow, and the transition to the mode of dispensing a liquid product to the consumer is carried out in two stages, the first of which transfers the entire flow of the unregulated flow, and in the second stage it is increased to the nominal value by adding the flow of the controlled flow, while maintaining the nominal head for the pump.

The specified technical result is also achieved by the fact that in the device for dispensing a liquid cryoproduct containing a cryogenic tank, a boost evaporator, a pump, a pipeline for supplying liquid from a container to a pump, a pipeline for dispensing liquid from a pump and a bypass pipe connecting the dispensing pipeline with a cryogenic tank, according to the invention, they are used centrifugal pump, on the dispensing pipeline to the point of its connection with the bypass pipeline, a constricting device is made in the form of a nozzle apparatus with a parallel constricting the control valve device.

The analysis of the prior art made it possible to establish that the applicant has not found an analogue characterized by features identical to all the essential features of the claimed invention, and therefore, it meets the criteria of "novelty" and "inventive step".

The invention is illustrated in the drawing, which shows a diagram of a system for issuing a liquid cryoproduct made by this method.

The system for dispensing liquid cryoproduct includes: a cryogenic tank 1 with liquid cryoproduct, for example nitrogen, a centrifugal pump 2, a pipeline 3 for supplying liquid from a tank 1 to a centrifugal pump 2 with a valve 4, a pipeline 5 for delivering liquid from a pump to a consumer 6 with a non-return valve 7 and a flow meter 8 , the narrowing device 9 in the form of a nozzle apparatus with a control valve 10 connected in parallel to it, made on the pipeline 5 to the place of its connection with the bypass pipe 11 with the valve 12 connecting the pipe 5 to the tank 1, will evaporate pressurization spruce 13 with a valve 14 for supplying liquid to the boost evaporator 13, as well as pressure gauges Ml and M2 for monitoring pressure after pump 2 and in tank 1 and temperature sensor T1 for monitoring the temperature of the pump during its cooling.

The method of issuing liquid cryoproduct is as follows.

A centrifugal pump is used to dispense liquid cryoproduct to the consumer, the consumer is switched to the dispensing mode by smoothly decreasing the bypass flow and maintaining the nominal pressure behind the pump, and the cryoproduct flow after the centrifugal pump is divided into regulated and unregulated flow, unregulated flow is from 70% to 80% of the nominal flow pump in the backpressure range after the pump from the boost pressure in the cryogenic tank to 0.95 of the nominal pressure behind the pump, and after cooling and starting us CA controlled flow is turned off, access to autonomous mode is carried out exclusively due to the flow of unregulated flow, and the transition to the mode of dispensing a liquid product to the consumer is carried out in two stages, at the first of which the entire flow of unregulated flow is transferred, and at the second stage it is increased to the nominal value for by adding the flow rate of the controlled flow, while maintaining the nominal pressure behind the pump.

The operation of the device issuing liquid cryoproduct is as follows.

Before starting the centrifugal pump 2, it is cooled, for which valves 4, 10 and 12 are opened. Under the action of a column of liquid in the tank 1, the pump 2 is gradually cooled, accompanied by an increase in pressure in the tank 1. The cooling process is monitored using a temperature sensor T1 and manometer M2. When the required temperature is reached, the pump 2 is launched to the tank 1. In this mode, the liquid cryoagent enters from the tank 1 into the liquid supply pipe 3, is captured by the pump 2, pushed through the constriction device 9 and the control valve 10, and then returns to the tank via the bypass pipe 11 1. The peculiarity of starting the pump 2 is that immediately after starting the pump 2, the control valve 10 is closed and behind the pump 2 a pressure is established, controlled by the pressure gauge M1, close to the nominal value, while narrowing the squeezing device 9, made in the form of a nozzle apparatus, is calculated for a flow rate equal to from 0.7 to 0.8 of the nominal flow rate of the pump 2 with back pressure behind the constricting device 9, which can vary over a wide range from the boost pressure in the tank 1 to 0.95 from the nominal pressure created by the pump 2, which provides a stable steady mode of operation of the pump, and therefore the entire system in all operating modes. After the pump 2 goes to stand-alone operation, i.e. to the tank 1, due to the evaporation of a part of the liquid in the boost evaporator 13, the pressure necessary for the nominal mode of the pump 2 is created in the gas cavity of the tank 1, which is controlled by the pressure gauge M2 and supported by the valve 14.

The transfer to the dispensing mode to the consumer 6 through the pipeline 5 with the non-return valve 7 installed in it and the flow meter 8 is carried out by smoothly closing the valve 12 of the bypass line 11. After the valve 12 is completely closed using the control valve 10, while controlling the flow through the flow meter 8 and pressure the pressure gauge M1 behind the pump 2 provides the output of the pump 2 and maintaining its operation in nominal mode.

Thus, the proposed technical solution allows for reliable start-up of the pump, a simple transfer from the stand-alone mode to the delivery mode to the consumer, and stable and stable operation of the system in all modes.

A comparison of the essential features of the proposed and known solutions gives reason to believe that the proposed technical solution meets the criteria of "inventive step" and "industrial applicability".

Claims (2)

1. A method of dispensing a liquid product to a consumer, including cooling the pump under the influence of the height of a liquid column in a cryogenic tank, starting the pump and reaching the rated autonomous mode of operation, bypassing the flow after the pump to the cryogenic tank, switching to the dispensing mode by increasing the flow to the consumer, maintaining the nominal mode the issuance of liquid cryoproduct to the consumer by adjusting the total flow issued to the consumer, characterized in that they use a centrifugal pump, the transition to the mode of dispensing The bitellet is also carried out by smoothly reducing the bypass flow and maintaining the nominal pressure behind the pump, the cryoproduct flow after the centrifugal pump is divided into an adjustable and unregulated flow, comprising from 70 to 80% of the nominal pump flow in the back pressure range from the boost pressure in the cryogenic tank to 0 , 95 of the nominal pressure behind the pump, and after cooling and starting the pump, the regulated flow is turned off, the autonomous operation is carried out exclusively due to the flow of unregulated eye, and the transition to the dispensing mode of the liquid product to the consumer in two stages, the first of which translate all unregulated flow stream, and the second step is increased to its nominal value by adding a controlled flow rate, while maintaining the nominal pressure of the pump. 2. A device for dispensing a liquid cryoproduct containing a cryogenic tank, a boost evaporator, a pump, a pipe for supplying liquid from a tank to a pump, a pipe for dispensing liquid from a pump and a bypass pipe connecting the discharge pipe to a cryogenic tank, characterized in that a centrifugal pump is used on the pipeline delivery to the place of its connection with the bypass pipe made narrowing device in the form of a nozzle apparatus with a control valve connected in parallel to the narrowing device.