CN111056159B - Zero-loss and energy-saving control process for liquid product - Google Patents

Abstract

A zero-loss and energy-saving control process for liquid products belongs to the technical field of storage methods for liquid products. The method is characterized in that: the head gas phase space of the container (1) stores inert gas for sealing the liquid product; when gas is discharged from the gas phase space, the gas discharged through the expiration system is received by a pressurization separation unit (9) and is pressurized and separated into liquid phase substances and non-condensable gas, the non-condensable gas is separated into organic component gas and residual gas by a membrane separation unit (21), and the liquid phase substances are collected and enter a collection unit (22). The process pressurizes and condenses VOC discharged with inert gas during expiration into liquid phase and collects the liquid phase, thereby avoiding the loss of liquid products and environmental pollution during expiration.

Description

Zero-loss and energy-saving control process for liquid product

Technical Field

A zero-loss and energy-saving control process for liquid products belongs to the technical field of storage methods for liquid products.

Background

Liquid products in the petrochemical field (such as oil, chemical products (such as ethylene, benzene, etc.) are generally toxic and flammable, and are generally sealed (i.e., inertly sealed) with inert gas during storage. Specifically, in a tank for storing a liquid product, a gas phase space is defined between the liquid product and a top wall of the tank, and the liquid product is hermetically stored by providing an inert gas in the gas phase space. In the case where the liquid product is expanded in volume due to the temperature rise of the liquid product or the liquid product is supplied to the tank from the outside, when the gas pressure in the gas phase space reaches a predetermined value, a part of the inert gas in the gas phase space is discharged through the expiration system to reduce the gas pressure in the gas phase space. However, VOC (volatile organic compounds) in the liquid product may volatilize into a gas phase space during storage and be discharged with inert gas during exhalation, resulting in loss of the liquid product and environmental pollution.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the defects of the prior art are overcome, the zero-loss and energy-saving control process for the liquid product is provided, and the storage process for the liquid product can reduce or avoid the loss of VOC in the expiration process and environmental pollution. .

The technical scheme adopted by the invention for solving the technical problems is as follows: the zero-loss and energy-saving control process for the liquid product is characterized in that the used equipment comprises a container for containing the liquid product, an expiration system connected with the container and a VOC recovery device;

the gas phase headspace of the vessel stores an inert gas for sealing the liquid product; venting gas from the gas phase space through an exhalation system when the gas pressure within the gas phase space increases to a first threshold; VOC recovery unit includes pressurization separator element, membrane separation unit and collection unit, utilizes the pressurization separator element to receive and passes through expiration system exhaust gas is right gas pressurization separation is liquid phase thing and noncondensable gas, and the membrane separation unit will noncondensable gas separation is organic component gas and residual gas, the liquid phase thing is collected and is got into collection unit.

The process pressurizes and condenses VOC discharged with inert gas during expiration into liquid phase and collects the liquid phase, thereby avoiding the loss of liquid products and environmental pollution during expiration.

The pressure separation unit comprises a compressor, a precooler and a condenser, the compressor, the precooler and the condenser are sequentially connected in series, a liquid phase outlet of the condenser is connected to the collection unit, a non-condensable gas outlet of the condenser is connected to a refrigerant inlet of the precooler, and a refrigerant outlet of the precooler is connected to the membrane separation unit; the gas discharged from the expiration system is pressurized by a compressor, the pressurized gas is precooled by a precooler, the precooled gas is further cooled by a condenser, the liquid phase of the condenser enters a collection unit for collection, and the non-condensable gas of the condenser enters a membrane separation unit for further separation after being used as a refrigerant of the precooler. According to the invention, pre-cooling is carried out firstly in the condensation process, then condensation is carried out, and the pre-cooled refrigerant adopts condensed non-condensable gas, so that the cold source is more fully utilized, the condensation efficiency is improved, and the membrane separation of the further-cooled non-condensable gas is easier to complete.

The pressurization separation unit further comprises a gas-liquid separation tank and a water supplementing tank, a water supply pipeline of the water supplementing tank is connected with a cooler of the compressor to supply water to the compressor so as to reduce the temperature rise of the gas during pressurization, the material pressurized by the compressor is subjected to gas-liquid separation through the gas-liquid separation tank, a liquid phase outlet of the gas-liquid separation tank is connected to the water supplementing tank, a gas phase outlet of the gas-liquid separation tank is connected to the precooler, a liquid phase separated by the gas-liquid separation tank enters the water supplementing tank for standby, and a gas phase separated by the gas-liquid separation tank enters the precooler for precooling. The materials are completely supplemented and reused, so that the separation efficiency is improved, the dependence and consumption on the outside are avoided, and the liquid materials are prevented from being polluted.

The water replenishment tank has a water outlet at the bottom and a residual liquid outlet on the side wall, the residual liquid outlet is connected to the collection unit, the water outlet is connected to the compressor, the liquid discharged from the residual liquid outlet is collected in the collection unit, and the water discharged from the water outlet is supplied to the compressor.

The pressurization separation unit further comprises a water tank, a refrigerant pump and a refrigeration compressor, wherein the water outlet and the refrigerant outlet of the condenser are respectively connected to the water tank, the refrigeration compressor is connected to the water tank, and the refrigerant pump is arranged on a refrigerant pipeline connected with the water tank, the condenser and/or the compressor; and water in the cooling water tank of the refrigeration compressor is cooled, and the water cooled by the refrigeration compressor is pumped to a refrigerant inlet of the condenser and/or the compressor by a refrigerant pump.

The residual gas outlet of the membrane separation unit is connected with an oil-gas catcher, the oil-gas catcher is used for collecting organic liquid phase substances in the residual gas, the liquid phase outlet of the oil-gas catcher is connected with the collection unit, and the oil-gas catcher collects the organic liquid phase substances and enters the collection unit for temporary storage; and/or the like and/or,

the collection unit is connected to the container by a return line; or returning the organic liquid phase to the vessel.

Preferably, a detection unit for detecting the pressure in the gas phase space is arranged on the container, the expiration system comprises an expiration pipeline, a control valve group is arranged on the expiration pipeline, and the control valve group is connected with the detection unit.

Preferably, the expiration system includes a buffer tank connected to the expiration pipeline, the buffer tank includes a gas supply port and an air supplement port, the gas supply port is connected to the inlet of the compressor, the pressurization separation unit includes an organic component gas conveying pipeline connected between the membrane separation unit and the compressor and a pressure reduction device arranged on the organic component gas conveying pipeline, and the pressure reduction device has an organic liquid outlet for discharging liquid to the collection unit and a gas outlet connected to the air supplement port.

Preferably, the container is provided with a plurality of containers, a plurality of gas phase collecting pipes are correspondingly arranged on the plurality of containers, and the plurality of gas phase collecting pipes are respectively connected with the expiration pipelines and are communicated with each other through the expiration pipelines.

Preferably, a plurality of said containers store at least two liquid products respectively, the pressurized separation unit comprises a plurality of said compressors corresponding to different ones of said liquid products respectively, said pressurized separation unit comprises at least one precooler and at least one condenser, the condenser tubes of at least one said precooler and at least one condenser being used for condensing different ones of said liquid products.

Preferably, the container is provided with a detection unit for detecting the pressure in the gas phase space, the expiration system comprises an expiration pipeline, the expiration pipeline is provided with a control valve group, the control valve group is connected with the detection unit, and the control valve group is set to be opened when the gas pressure in the expiration pipeline rises to a first threshold value and to be closed when the gas pressure in the gas phase space falls to a second threshold value.

Preferably, the expiration system includes a buffer tank connected to the expiration pipeline, the buffer tank includes a gas supply port and an air supplement port, the gas supply port is connected to the inlet of the compressor, the pressurization separation unit includes an organic component gas conveying pipeline connected between the membrane separation unit and the compressor and a pressure reduction device arranged on the organic component gas conveying pipeline, and the pressure reduction device has an organic liquid outlet for discharging liquid to the collection unit and a gas outlet connected to the air supplement port.

Preferably, the storage device comprises an air suction system for providing inert gas from the air storage tank to the gas phase space, the air suction system comprises an air supply pipeline communicating the air storage tank with the gas phase space, the air supply pipeline is provided with an inert valve, and the inert valve is set to be opened when the gas pressure in the gas phase space drops to a third threshold value.

Compared with the prior art, the zero-loss and energy-saving control process for the liquid product has the beneficial effects that: the process is used for storing toxic and flammable dangerous liquid products (such as oil materials, chemical products (such as ethylene, benzene and the like)) in the field of petrochemical industry, a part of inert seal gas in a gas phase space is discharged in an expiration system, so that the internal closed circulation of VOC (volatile organic compounds) in the liquid products is realized in the system when the gas pressure in the gas phase space is reduced.

Drawings

FIG. 1 is a schematic view of the structure of the apparatus used in the zero-loss and energy-saving control process of a liquid product of the present invention.

The device comprises a container 1, a container 2, a detection unit 3, an expiratory valve 4, a gas phase collecting pipe 5, a flame arrester 6, a buffer tank 7, an expiratory pipeline 8, a control valve group 9, a pressurization separation unit 10, a compressor 11, a gas-liquid separation tank 12, a precooler 13, a condenser 14, a water supplementing tank 15, a water storage tank 16, a residual liquid tank 17, an organic component conveying pipeline 18, a pressure reducing device 19, a refrigerant pump 20, a refrigeration compressor 21, a membrane separation unit 22, a collection unit 23, a collection tank 24, an oil gas trap 25, a gas storage tank 26, a gas supply pipeline 27 and an inert seal valve.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

Examples

Referring to the attached figure 1, the invention relates to a zero-loss and energy-saving control process for a liquid product, which uses equipment comprising: a container 1 for containing a liquid product, the container 1 having a gas phase space at the top for sealing the liquid product by an inert gas; an exhalation system for exhausting gas from the gas phase space when the gas pressure within the gas phase space increases to a first threshold; the VOC recovery device comprises a pressurizing separation unit 9, a membrane separation unit 21 and a collection unit 22, wherein the pressurizing separation unit 9 is used for receiving gas exhausted from an expiration system and pressurizing and separating the gas into liquid phase substances and non-condensable gas, the membrane separation unit 21 is used for separating the non-condensable gas into organic component gas and residual gas, an organic component gas outlet of the membrane separation unit 21 is connected with the pressurizing separation unit 9 so that the organic component gas can enter the pressurizing separation unit 9 for separation, and the collection unit 22 is used for collecting the liquid phase substances.

The VOC recovery device can pressurize and condense VOC discharged along with inert gas during expiration into liquid phase substances and collect the liquid phase substances, thereby avoiding the loss of liquid products and environmental pollution during expiration.

The pressurizing separation unit 9 is configured to pressurize the gas and separate the gas into a liquid phase and a non-condensable gas, and the pressurizing is performed to facilitate the separation of the liquid phase and the operation of the membrane separation unit 21 to separate the organic component gas and the residual gas. The recovery efficiency of the liquid phase can be further improved by causing the organic component gas separated by the membrane separation unit 21 to enter the pressurized separation unit 9.

In particular, the pressurized separation unit 9 may effect separation of the liquid phase and the non-condensable gases by condensation. The pressure separation unit 9 may include a compressor 10, a pre-cooler 12 and a condenser 13, the compressor 10 is configured to pressurize the gas discharged from the expiratory system, the pre-cooler 12 is configured to pre-cool the pressurized gas, the condenser 13 is configured to further cool the pre-cooled gas, a liquid phase outlet of the condenser 13 is connected to the collection unit 22, a non-condensable gas outlet of the condenser 13 is connected to a refrigerant inlet of the pre-cooler 12, and a refrigerant outlet of the pre-cooler 13 is connected to the membrane separation unit 21. In this embodiment, the condensing temperature of the liquid phase in the pressurized gas is increased, and most of the liquid phase can be condensed and discharged through the liquid phase outlet of the condenser 13 while passing through the precooler 12 and the condenser 13, and finally collected to the collection unit 22.

Specifically, the pressurized gas enters the precooler 12 to exchange heat with the refrigerant in the precooler 12, and the precooled gas enters the condenser 13 to exchange heat with the refrigerant in the condenser 13 to be further condensed, so that the liquid phase substance is separated from the non-condensable gas. The liquid phase is discharged from the liquid phase outlet of the condenser 13 and collected by the collection unit 22. The non-condensable gas is discharged from the non-condensable gas outlet of condenser 13 and enters the refrigerant inlet of precooler 12 to be used as the refrigerant in precooler 12, and is discharged from the refrigerant outlet of precooler 12 after participating in the heat exchange in precooler 12 and is separated into the organic component gas and the residual gas by membrane separation unit 21. It can be understood that the non-condensable gas is still in a pressurized state when entering the membrane separation unit 21, which is beneficial for the separation of the membrane separation unit 21, and the separated organic component gas is also in a pressurized state, so that the organic component gas has a pressure difference with the gas at the inlet of the compressor 10, and when the organic component gas outlet of the membrane separation unit 21 is connected with the inlet of the compressor 10 through a pipeline, the organic component gas can automatically return to the inlet of the compressor 10 under the action of the pressure difference.

As shown in fig. 1, the pressure separation unit 9 includes a gas-liquid separation tank 11 and a water supply tank 14, the water supply tank 14 is used to supply water to the compressor 10 to reduce the temperature rise of the gas during the pressure, an inlet of the gas-liquid separation tank 11 is connected to an outlet of the compressor 10 to perform gas-liquid separation of the compressed material, a liquid phase outlet of the gas-liquid separation tank 11 is connected to the water supply tank 14, and a gas phase outlet of the gas-liquid separation tank 11 is connected to the precooler 12. In order to avoid excessive temperature rise of the gas during pressurization, water is supplied to the compressor 10 through the water replenishing tank 14 to reduce the temperature. The water added for separating and cooling can lead the pressurized material to pass through the gas-liquid separation tank 11 first, so as to carry out subsequent condensation on the separated pressurized gas after the gas-liquid separation of the material.

In this embodiment, in the liquid phase after the gas-liquid separation of the material, a small amount of the liquid phase is the residual liquid of the organic components to be recovered, and most of the liquid phase is the water supplied from the water replenishing tank 14 to the compressor 10, so that the liquid phase outlet of the gas-liquid separation tank 11 can be connected to the water replenishing tank 14 to recycle the cooled water. To further improve the recovery of organic components and to purify the recycle water, the makeup tank 14 may have a water outlet at the bottom and a residue outlet at the side wall, and the liquid discharged from the residue outlet can be collected in the collection unit 22 and the water discharged from the water outlet can be supplied to the compressor 10. Since the organic components are generally less dense than water, the liquid phase will stratify in the make-up water tank 14, with the organic components in the upper layer and discharged through the raffinate outlet for collection in the collection unit 22 and the water in the lower layer and discharged through the water outlet and supplied to the compressor 10 for cooling.

The pressure separation unit 9 includes a water tank, a refrigerant pump 19 and a refrigeration compressor 20, a water outlet and a refrigerant outlet of the condenser 13 are respectively connected to the water tank, the refrigeration compressor 20 is used for cooling water in the water tank, the refrigerant pump 19 is used for pumping the water cooled by the refrigeration compressor 20 to a refrigerant inlet of the condenser 13 and/or the compressor 10, thereby forming cooling water circulation in the apparatus of the present invention and avoiding loss of the cooling water.

For utilizing water and raffinate respectively, set up water storage tank 15 and raffinate jar 16 respectively, water outlet of water supplementing jar 14 connects in water storage tank 15, and the raffinate exit linkage in raffinate jar 16 can ensure that the liquid phase in water supplementing jar 14 stratifies fully for water and raffinate that the layering obtained can get into water storage tank 15 and raffinate jar 16 respectively.

The residue tank 16 may be in communication with a collection unit 22 to further reduce the loss of organic components. The water storage tank 15 may be communicated with a water tank, water discharged from a refrigerant outlet of the condenser 13 may be collected into the water tank after being cooled by the refrigeration compressor 20, and the water in the water tank may be pumped into the condenser 13 as a refrigerant by the refrigerant pump 19 or pumped into the compressor 10 for cooling.

The liquid phase discharged from the refrigerant outlet of the precooler 12 may be stored in the collection tank 23, and the collection tank 23 may be configured similarly to the makeup tank 14, that is, the collection tank 23 has a drain port at the bottom and an organic matter discharge port at the side, and the liquid phase may be first layered in the collection tank 23, and then the organic matter at the upper layer is sent to the collection unit 22 through the organic matter discharge port, so as to ensure the purity of the organic matter in the collection unit 22. The water drained from the drain port of the collection tank 23 may be sent to a water tank to participate in condensation and temperature reduction.

In order to control the exhaust operation of the exhalation system, the container 1 is provided with a detection unit 2 for detecting the pressure in the gas phase space, the exhalation system comprises an exhalation pipeline 7, the exhalation pipeline 7 is provided with a control valve group 8, the control valve group 8 is connected with the detection unit 2, and the control valve group 8 is set to be opened when the gas pressure in the exhalation pipeline 7 rises to a first threshold value and to be closed when the gas pressure in the gas phase space falls to a second threshold value. Wherein the first threshold is not less than the second threshold. For example, the first threshold may be 0.6 to 0.7KPa and the second threshold may be 0.5 to 0.6 KPa.

In order to avoid that the control valve group 8 can not be normally opened due to faults, the container 1 is provided with the expiratory valve 3, and under the condition that the control valve group 8 can not be normally opened, when the pressure in the gas phase space reaches a preset value, the expiratory valve 3 is opened to emergently exhaust to the atmosphere. Wherein the exhalation valve 3 may be set to open at a predetermined value above the first threshold value. For example, in the case where the first threshold value is 0.5 to 0.6KPa, the predetermined value is 1.9 to 2.0 KPa.

To facilitate the design and structural optimization of the process route, the exhalation system includes a buffer tank 6 connected to an exhalation tube 7. Wherein, the buffer tank 6 includes an air supply port connected to an inlet of the compressor 10 and an air supplement port. A check valve may be provided in a line between the air supply port and the inlet of the compressor 10 to open when the pressure in the buffer tank 6 reaches a predetermined threshold, and to unidirectionally supply air from the buffer tank 6 to the compressor 10.

The pressure separation unit 9 includes an organic component transfer pipe 17 connected between the membrane separation unit 21 and the compressor 10, and a pressure reducing device 18 provided on the organic component transfer pipe 17, the pressure reducing device 18 having an organic liquid outlet for discharging liquid to the collection unit 22 and a gas outlet connected to the gas replenishment port. As described above, the organic component gas separated by the membrane separation unit 21 is still in a state of high pressure, and directly returned to the compressor 10 may adversely affect the performance and life of the compressor 10, and the pressure of the organic component gas can be reduced by providing the pressure reducing device 18, and the pressure of the organic component gas can be further reduced by sending the organic component gas to the buffer tank 6, thereby eliminating the adverse effect on the compressor 10. The pressure reducing device 18 may be in various suitable forms, and may be a pressure reducing valve, for example.

In addition, the organic component in the organic component gas may be liquefied while being decompressed by the decompression device 18, and thus may be discharged through the organic liquid outlet and collected in the collection unit 22. Specifically, the organic liquid outlet may be connected to the water replenishment tank 14 so as to be layered in the water replenishment tank 14 and to allow the organic component to be recovered to the collection unit 22.

The storage apparatus includes a plurality of containers 1 and a plurality of gas phase collection pipes 4 respectively corresponding to the plurality of containers 1, the plurality of gas phase collection pipes 4 being respectively connected to the expiration pipes 7 and communicating with each other through the expiration pipes 7. Wherein the gas phase spaces of the plurality of containers 1 can be pressure-equalized with each other by the gas phase collecting pipe 4 so as to be equalized by the gas phase spaces of the other containers 1 when the gas pressure in the gas phase space of a part of the containers 1 fluctuates. Specifically, when the gas pressure in the gas phase space of one container 1 rises, the container 1 exhales outwards, and the exhaled gas can enter the gas phase collecting pipe 4 of the other container 1 through the exhalation pipe 7 and can enter the gas phase space of the other container 1. The gas pressure in the gas phase space of all the containers 1 rises, i.e. all the containers 1 exhale outwards, the exhaled gas will enter the exhalation pipe 7 and exhale by opening the control valve block 8 when the pressure in the exhalation pipe 7 rises to the first threshold value, and then the organic components are recovered from the exhaled gas by the VOC recovery device. Wherein, can be provided with spark arrester 5 on the gaseous phase collecting pipe 4, for the maintenance spark arrester 5, can set up manual valve in spark arrester 5's upper reaches and low reaches, and manual valve is for normally opening, only closes when maintaining spark arrester 5 to carry out maintenance operation.

Of course, when the pressure fluctuations are balanced with each other by using the gas phase spaces of the plurality of containers 1, the same liquid product should be stored in the plurality of containers 1 so as not to contaminate each other.

In the case where different liquid products are stored in a plurality of containers 1 (i.e., a plurality of containers 1 are used for storing at least two liquid products), only the containers 1 storing the same liquid product are communicated with each other through the gas phase collecting pipe 4, thereby avoiding contamination caused by the communication of gas phase spaces of different containers 1. The pressurized separation unit 9 comprises a plurality of compressors 10 corresponding to the different liquid products, respectively, the pressurized separation unit 9 comprising at least one precooler 12 and at least one condenser 13, the condenser pipes of the at least one precooler 12 and the at least one condenser 13 being used for condensing the different liquid products. In particular, the gases exhaled by the containers 1 containing two different liquid products can be compressed separately and introduced into different condensation tubes inside the precooler 12 (and the condenser 13) in order to condense the exhaled air containing different VOCs using the refrigerant inside the shell of the same precooler 12 (and the condenser 13). Of course, a plurality of corresponding buffer tanks 6 and collecting units 22 are provided to collect different exhaled air and organic components.

The VOC in the residual gas is further removed using an oil and gas trap 24. Specifically, the residual gas outlet of the membrane separation unit 21 is connected to an oil gas trap 24 for collecting the organic liquid phase in the residual gas, and the liquid phase outlet of the oil gas trap 24 is connected to the collection unit 22. Wherein the concentration of the inerting gas in the residual gas treated by the oil gas catcher 24 is further increased to meet the standard for inerting, so that the residual gas can be collected and used for inerting. Specifically, the storage facility may include a gas tank 25 for storing inert gas, and the gas phase outlet of the trap 24 is connected to the gas tank 25.

In addition, the organic component collected by the collection unit 22 is the same as the liquid product stored in the container 1, and may be returned to the container 1. In particular, the collection unit 22 is arranged to be able to feed back the collected liquid phase into the container 1. Specifically, the collection unit 22 can feed back the collected liquid phase into the container 1 by inert gas in the gas container 25. This makes it possible to use the collected residual gas as a driving force for returning the collected liquid phase to the container 1, and to ensure safety without introducing other impurities.

In order to maintain the necessary gas pressure when the gas pressure in the gas phase space is reduced, the storage apparatus includes a suction system for supplying inert gas from the gas storage tank 25 to the gas phase space. The air suction system comprises an air supply pipeline 26 communicating the air storage tank 25 and the gas phase space, the air supply pipeline 26 is provided with an idle sealing valve 27, and the idle sealing valve 27 is set to be opened when the gas pressure in the gas phase space is reduced to a third threshold value. The third threshold may be 0.4 to 0.5 KPa.

A method of storing a liquid product, wherein the method of storing comprises: s1, pressurizing and separating gas exhausted when the container 1 for storing the liquid product exhales to form a liquid phase and a non-condensable gas; s2, carrying out membrane separation on the non-condensable gas to form organic component gas and residual gas, and carrying out pressure separation after the organic component gas is decompressed; and S3, collecting liquid phase substances.

The method of the invention avoids the loss of liquid products during expiration by pressurizing and condensing the VOC in the gas exhausted during expiration into a liquid phase and collecting the liquid phase.

Preferably, to reduce product wastage within the container 1, the method comprises: s4, returning the collected liquid phase to the container 1.

The residual gas obtained by the method is basically inert gas, and in order to reduce the loss of the inert gas, the method comprises the following steps: s5, collecting organic liquid phase substances in the residual gas and purifying the residual gas to reach the inert gas sealing standard; s6, collecting the purified residual gas and supplementing the collected residual gas to the gas phase space when the container 1 sucks the gas.

Wherein, according to the need, corresponding thresholds can be set to control the exhalation and inhalation of the container 1. Specifically, the method includes exhaling when the gas pressure in the gas phase space rises to a first threshold and inhaling when the gas pressure in the gas phase space falls to a third threshold. Wherein, the first threshold value can be 0.6-0.7KPa, and the third threshold value can be 0.4-0.5 KPa.

When the exhaled gas is pressurized, it may result in excessive gas temperature rise, which may adversely affect subsequent processing. To this end, step S1 may include: and S11, pressurizing the gas and adding water to reduce the temperature rise during pressurizing the gas. In order to reduce the loss of the processing medium, preferably, step S1 further includes: s12, the pressurized gas-liquid mixture is subjected to gas-liquid separation, and water is replenished from the separated liquid phase at step S11. In S12, the separated liquid phase may be cooled before being used for water replenishment in step S11. The method may be carried out by a storage apparatus for a liquid product of the present invention.

The operation of the storage device for liquid products of the present invention is briefly described below with reference to the embodiment of fig. 1. Wherein the container 1 is a can body.

When the gas pressure in the gas phase space of one container 1 reaches, for example, 0.4KPa, the container 1 starts to exhale. When the gas pressure fluctuation in the gas phase space is small, the expired gas enters other containers 1 through other gas phase collecting pipes 4 connected with the expired gas pipeline 7, and the tiny pressure fluctuation is balanced. When the pressure fluctuation of the gas in the gas phase space is large, the pressure in the expiration pipeline 7 is increased until the pressure in the expiration pipeline 7 reaches a first threshold value (for example, 0.6 KPa), the control valve group 8 is opened, the expiration enters the buffer tank 6, and then enters the pressurization separation unit 9 for pressurization and condensation. Wherein the compressor 10 may be arranged to compress the gas to e.g. 0.7-0.8MPa and may be arranged to start the compressor 10 when the gas pressure in the buffer tank 6 reaches e.g. 0.6kPa and to stop the compressor 10 when the pressure drops to e.g. 0.05 kPa. After condensation, the liquid phase matter collected by the residual liquid tank 16 and the oil gas catcher 24 is collected to the collecting unit 22, and is pumped into the container 1 through the inert gas in the gas storage tank 25, and the residual gas enters the gas storage tank 25 for suction. Wherein the control valve block 8 closes when the pressure in the expiratory conduit 7 decreases to a second threshold (e.g. 0.45 KPa).

The organic component gas separated by the membrane separation unit has a relatively high pressure, for example, still 0.7 to 0.8MPa, and is first reduced in pressure to a pressure level (for example, 0.6 MPa) at the inlet of the compressor 10 by the pressure reducing device 18 and then fed into the buffer tank 6.

When the control valve group 8 fails to open, the pressure in the container 1 continuously rises to 1.765KPa, the exhalation valve 3 is opened, and the gas in the container 1 is discharged to the atmosphere in an emergency.

When the gas pressure in the gas phase space of one of the vessels 1 is lower than a third threshold value (for example, 0.4 kPa), the inert seal valve 27 is opened to suck the gas through the suction system, and the inert seal gas in the gas storage tank 25 is supplied into the vessel 1 through the gas supply pipe 26.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

Claims (8)

1. A zero-loss and energy-saving control process for liquid products is characterized in that the used equipment comprises a container (1) for containing the liquid products, an expiration system connected with the container (1) and a VOC recovery device;

the head gas-phase space of the container (1) stores inert sealing gas for sealing the liquid product; venting gas from the gas phase space through an exhalation system when the gas pressure within the gas phase space increases to a first threshold; the VOC recovery device comprises a pressurization separation unit (9), a membrane separation unit (21) and a collection unit (22), wherein the pressurization separation unit (9) is used for receiving gas discharged through the expiration system and pressurizing and separating the gas into a liquid phase substance and a non-condensable gas, the membrane separation unit (21) is used for separating the non-condensable gas into an organic component gas and a residual gas, and the liquid phase substance is collected and enters the collection unit (22);

the pressure separation unit (9) comprises a compressor (10), a precooler (12) and a condenser (13), the compressor (10), the precooler (12) and the condenser (13) are sequentially connected in series, a liquid phase outlet of the condenser (13) is connected to the collection unit (22), a non-condensable gas outlet of the condenser (13) is connected to a refrigerant inlet of the precooler (12), and a refrigerant outlet of the precooler (12) is connected to the membrane separation unit (21); the method comprises the steps that gas exhausted from the expiration system is pressurized by a compressor (10), the pressurized gas is pre-cooled by a pre-cooler (12), the pre-cooled gas is further cooled by a condenser (13), a liquid phase of the condenser (13) enters a collecting unit (22) for collection, and non-condensable gas of the condenser (13) is used as a refrigerant of the pre-cooler (12) and then enters a membrane separation unit (21) for further separation;

the pressurization separation unit (9) further comprises a gas-liquid separation tank (11) and a water supplementing tank (14), a water supply pipeline of the water supplementing tank (14) is connected with a cooler of the compressor (10) to supply water to the compressor (10) so as to reduce the temperature rise of gas during pressurization, the gas-liquid separation of materials pressurized by the compressor is completed through the gas-liquid separation tank (11), a liquid phase outlet of the gas-liquid separation tank (11) is connected to the water supplementing tank (14), a gas phase outlet of the gas-liquid separation tank (11) is connected to the precooler (12), liquid phase separated by the gas-liquid separation tank (11) enters the water supplementing tank (14) for standby, and gas phase separated by the gas-liquid separation tank (11) enters the precooler (12) for precooling.

2. The liquid product zero-loss and energy-saving control process according to claim 1, characterized in that: the water replenishment tank (14) has a water outlet at the bottom and a residual liquid outlet on the side wall, the residual liquid outlet is connected to the collection unit (22), the water outlet is connected to the compressor (10), the liquid discharged from the residual liquid outlet is collected in the collection unit (22), and the water discharged from the water outlet is supplied to the compressor (10).

3. The liquid product zero-loss and energy-saving control process according to claim 2, characterized in that: the pressurization separation unit (9) further comprises a water tank, a refrigerant pump (19) and a refrigeration compressor (20), the water outlet and the refrigerant outlet of the condenser (13) are respectively connected to the water tank, the refrigeration compressor (20) is connected to the water tank, and the refrigerant pump (19) is arranged on a refrigerant pipeline connected with the water tank, the condenser (13) and/or the compressor (10); the water in the water tank is cooled by a refrigeration compressor (20), and the water cooled by the refrigeration compressor (20) is pumped to a refrigerant inlet of the condenser (13) and/or the compressor (10) by a refrigerant pump (19).

4. The liquid product zero-loss and energy-saving control process according to claim 1, characterized in that: the residual gas outlet of the membrane separation unit (21) is connected with an oil-gas catcher (24), the oil-gas catcher (24) is used for collecting organic liquid phase substances in the residual gas, the liquid phase outlet of the oil-gas catcher (24) is connected with the collection unit (22), and the oil-gas catcher (24) collects the organic liquid phase substances and enters the collection unit (22) for temporary storage; and/or the like and/or,

the collection unit (22) is connected to the container (1) by a return line; or returning the organic liquid phase to the vessel (1).

5. The liquid product zero-loss and energy-saving control process according to claim 1, characterized in that: be provided with on container (1) and be used for detecting element (2) of the pressure in the gas phase space, the expiration system includes exhale pipeline (7), be provided with valve unit (8) on exhale pipeline (7), valve unit (8) with detecting element (2) are connected.

6. The liquid product zero-loss and energy-saving control process according to claim 5, characterized in that: expiration system including connect in buffer tank (6) of expiration pipeline (7), buffer tank (6) include gas supply mouth and tonifying qi mouth, the gas supply mouth with the entry linkage of compressor (10), pressurization separating element (9) including connect in membrane separation unit (21) with organic component conveying pipe (17) between compressor (10) and set up pressure relief device (18) on organic component conveying pipe (17), pressure relief device (18) have be used for to collect the organic liquid export of unit (22) play liquid and with the gas outlet that the tonifying qi mouth is connected.

7. The liquid product zero-loss and energy-saving control process according to claim 6, characterized in that the container (1) is provided with a plurality of gas phase collecting pipes (4), the plurality of gas phase collecting pipes (4) are correspondingly provided with a plurality of gas phase collecting pipes (1), and the plurality of gas phase collecting pipes (4) are respectively connected with the expiration pipelines (7) and are communicated with each other through the expiration pipelines (7).

8. The process according to claim 7, wherein a plurality of said containers (1) store at least two liquid products respectively, a pressurized separation unit (9) comprises a plurality of said compressors (10) corresponding to different said liquid products respectively, said pressurized separation unit (9) comprises at least one precooler (12) and at least one condenser (13), the condensation ducts of at least one said precooler (12) and at least one condenser (13) being used for condensing different said liquid products.

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