Combined air extraction system with active exhaust

Abstract

The application relates to a combined exhaust system with active exhaust, which comprises a first-stage steam exhauster, a flash distillation chamber, a second-stage steam exhauster, a condenser and a water-jet exhauster. The condenser is connected with the flash distillation chamber through the first-stage steam exhauster, which is driven by steam to exhaust the gas generated in the seawater desalination operation from the flash distillation chamber, so that the exhausted gas and steam are condensed in the first-stage condensing cavity of the condenser. The second-stage steam exhauster is connected with the condenser, which is driven by steam to exhaust the first-stage condensing cavity of the condenser, so that the exhausted gas and steam are condensed in the second-stage condensing cavity of the condenser, and the second-stage condensed water is mixed with the first-stage condensed water and discharged. The water-jet exhauster is connected with the condenser, which is driven by seawater to exhaust the second-stage uncooled non-condensable gas and carbon dioxide gas of the condenser, and the exhausted gas is discharged with the seawater of the water-jet exhauster.

Description

TECHNICAL FIELD

[0001] The application relates to a combined air extraction system with active exhaust for ship thermal seawater desalination BACKGROUND

[0002] At present, in the field of ship thermal seawater desalination technology, a steam air extractor is usually used to extract air from a distillation chamber, so that seawater flashes at low pressure. For seawater, not only non-condensable gases such as oxygen and nitrogen are dissolved, but also carbon dioxide gas is dissolved, and when seawater is heated, carbonates decompose and carbon dioxide gas escapes. Therefore, the gas extracted by the steam air extractor is not air, but gas with a higher proportion of carbon dioxide than normal air. If the extracted gas is directly discharged into the cabin, and the cabin has no good ventilation conditions, as the carbon dioxide gas accumulates, safety problems such as operator hypoxia may occur.

[0003] Therefore, it is necessary to design a combined air extraction system with active exhaust, which can discharge the gas generated during the operation of the thermal seawater desalination device with seawater from the cabin, ensure that the cabin environment meets the requirements of the operator, and avoid safety problems. SUMMARY

[0004] In order to ensure that the gas generated during the operation of the thermal seawater desalination device does not affect the cabin environment, the application provides a combined air extraction system with active exhaust.

[0005] To achieve the above purpose, the technical scheme of the application is: a combined air extraction system with active exhaust, comprising a first-stage steam air extractor, a flash distillation chamber, a second-stage steam air extractor, a condenser, a seawater pump and a water jet air extractor. The condenser is connected to the flash distillation chamber through the first-stage steam air extractor, and is used to drive the first-stage steam air extractor by steam to extract the gas generated during the operation of the seawater desalination device from the flash distillation chamber, so that the extracted gas and steam are condensed in the first-stage condensing cavity in the condenser. The second-stage steam air extractor is connected to the condenser, and is used to drive the second-stage steam air extractor by steam to extract the first-stage condensing cavity of the condenser, so that the extracted gas and steam are condensed in the second-stage condensing cavity in the condenser, and the second-stage condensed water is mixed with the first-stage condensed water and discharged. The water jet air extractor is connected to the condenser, and is used to drive the water jet air extractor by seawater to extract the second-stage non-condensable gas and carbon dioxide gas in the condenser, and the extracted gas is discharged with the seawater of the water jet air extractor.

[0006] Further, a pressure sensor is arranged on the second-stage condensing cavity of the condenser, which is used to monitor and control the pressure in the second-stage condensing cavity in real time.

[0007] Further, the seawater pump is connected with the water jet air ejector through the electric regulating valve, so that the pressure in the condenser is maintained in a certain pressure range through the electric regulating valve, and the discharge of the non-condensable gas and the smooth discharge of the condensed water are ensured.

[0008] Further, when the pressure in the condenser is too low, the opening of the electric regulating valve on the outlet pipeline of the seawater pump becomes smaller, the suction capacity of the water jet air ejector is reduced, and the pressure in the condenser is increased; when the pressure in the condenser is too large, the opening of the electric regulating valve on the outlet pipeline of the seawater pump becomes larger, the suction capacity of the water jet air ejector is increased, and the pressure in the condenser is reduced.

[0009] Further, the condenser is an integrated condenser integrated by two condensers, which can save the condenser pipeline and size weight.

[0010] The beneficial effects of the present application are:

[0011] (1) The two-stage steam air ejector with intermediate condensation is used in the system of the present application to perform vacuumizing on the flash distillation chamber, which can minimize the consumption of steam;

[0012] (2) The seawater pump is used in the system of the present application to drive the water jet air ejector to remove the gas in the condenser, and the gas generated during the seawater desalination process is discharged with the seawater from the cabin, which does not affect the cabin environment;

[0013] (3) When the seawater desalination device fails, the valve switching can directly utilize the plate heat exchanger to cool the hot water, and ensure the operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a combined air extraction system with active exhaust of the present application;

[0015] In the figure: 1-first stage steam air ejector, 2-flash distillation chamber, 3-pressure sensor, 4-second stage steam air ejector, 5-condenser, 6-seawater pump, 7-electric regulating valve, 8-water jet air ejector. DETAILED DESCRIPTION

[0016] The present application will be further described below in combination with the drawings and examples.

[0017] As shown in the drawings, Figure 1 The combined air extraction system with active exhaust provided by the embodiment of the present application comprises a first stage steam air ejector 1, a flash distillation chamber 2, a pressure sensor 3, a second stage steam air ejector 4, a condenser 5, a seawater pump 6, an electric regulating valve 7, and a water jet air ejector 8.

[0018] Condenser 5 is connected with flash distillation chamber 2 through first-stage steam ejector 1, for driving first-stage steam ejector 1 by steam, and for extracting gas generated in the seawater desalination operation from flash distillation chamber 2, so that the extracted gas and steam are condensed in the first-stage condensing cavity of condenser 5; second-stage steam ejector 4 is connected with condenser 5, for driving second-stage steam ejector 4 by steam, and for extracting the first-stage condensing cavity of condenser 5, so that the extracted gas and steam are condensed in the second-stage condensing cavity of condenser 5, and the second-stage condensed water is mixed with the first-stage condensed water and discharged.

[0019] Water jet ejector 8 is connected with condenser 5, for driving water jet ejector 8 by seawater, and for extracting the second-stage uncooled non-condensable gas and carbon dioxide gas of condenser 5, and for discharging the extracted gas with seawater of water jet ejector 8.

[0020] Pressure sensor 3 is arranged on the second-stage condensing cavity of condenser 5, for controlling the pressure in the second-stage condensing cavity. Seawater pump 6 is connected with water jet ejector 8 through electric regulating valve 7.

[0021] The combined gas extraction system with active exhaust of the present application has the following features:

[0022] 1. The system can extract carbon dioxide and other gases generated in the operation of seawater desalination device by water jet ejector, and then directly discharge the gases outside the cabin.

[0023] 2. The condenser used in the system is an integrated condenser, which is integrated with two condensers, so that the equipment pipeline and size and weight can be greatly saved.

[0024] For example, Figure 1As shown, when the seawater desalination device is in operation, a large amount of gas such as carbon dioxide is generated in the flash distillation chamber 2, under the action of the first-stage steam ejector 1, the mixture of gas and steam enters the first-stage condensing cavity in the condenser 5; the steam is cooled to condensate in the first-stage condensing cavity, under the action of the second-stage steam ejector 4, the mixture of gas and steam enters the second-stage condensing cavity in the condenser 5 for cooling; the second-stage condensate and the first-stage condensate are mixed and discharged; under the action of the water jet ejector 8, the gas not condensed in the second-stage condensing cavity is sucked out and discharged outside the cabin together with the seawater of the water jet ejector 8. The water jet ejector 8 is driven by the seawater pump 6, an electric regulating valve 7 is arranged on the outlet pipeline of the seawater pump 6, the system controls the opening degree of the electric regulating valve 7 by monitoring the pressure value of the pressure sensor 3 on the condenser 5 in real time, when the pressure in the condenser 5 is too low, the opening degree of the electric regulating valve 7 on the outlet pipeline of the seawater pump 6 becomes smaller, the suction capacity of the water jet ejector 8 decreases, so that the pressure in the condenser 5 increases; when the pressure in the condenser 5 is too large, the opening degree of the electric regulating valve 7 on the outlet pipeline of the seawater pump 6 becomes larger, the suction capacity of the water jet ejector 8 increases, so that the pressure in the condenser 5 decreases. Through the electric regulating valve 7, the pressure in the condenser 5 can be maintained within a certain pressure range, so as to ensure the discharge of non-condensable gas and the smooth discharge of condensate.

Claims

1. A combined air extraction system with active exhaust, characterized in that: The system includes a first-stage steam ejector, a flash distillation chamber, a second-stage steam ejector, a condenser, a seawater pump, and a water jet ejector. The condenser is connected to the flash distillation chamber via the first-stage steam ejector and is used to drive the first-stage steam ejector with steam to extract the gas generated during the seawater desalination process from the flash distillation chamber. The extracted gas and steam are then condensed in the first-stage condensation chamber within the condenser. The second-stage steam ejector is connected to the condenser and is used to drive the second-stage steam ejector with steam to extract gas from the first-stage condensation chamber of the condenser. The extracted gas and vapor are condensed in the second-stage condensation chamber of the condenser. The second-stage condensate mixes with the first-stage condensate and is then discharged. A water jet ejector is connected to the condenser and is driven by seawater to extract uncooled non-condensable gases and carbon dioxide from the second stage of the condenser. The extracted gas is discharged with the seawater from the water jet ejector. A seawater pump is connected to the water jet ejector via an electric regulating valve to maintain the pressure inside the condenser within a certain range, ensuring the discharge of non-condensable gases and the smooth discharge of condensate. The condenser is an integrated condenser that combines two condensers into one unit, which can save on condenser piping, size, and weight; a pressure sensor is installed on the second-stage condensing chamber of the condenser to monitor and control the pressure inside the second-stage condensing chamber in real time.

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