RU206404U1 - Marine compressor unit for high pressure gaseous nitrogen production - Google Patents

Abstract

The claimed utility model relates to the field of marine equipment, namely to installations for obtaining (producing) a gas mixture with a high nitrogen content from atmospheric air, which is used to reduce the fire hazard when performing technological operations with combustible substances on ships. high pressure includes a screw compressor, an air preparation unit, a membrane gas separation unit, a piston compressor, a filter dryer and a liquid cooling system for compressors located in a single housing and connected in series with pipelines, while a tank for gaseous nitrogen is placed between the membrane gas separation unit and the piston compressor ... The unit is characterized by the fact that the liquid cooling system of the compressors includes two circuits - an internal closed circuit with fresh water circulating in it, which, through heat exchange, provides cooling of heat-loaded elements of screw and reciprocating compressors, and an external circuit connected through the branch pipes made in the unit body to an external source cooling (seawater) to enable cooling of fresh water circulating in the internal circuit.

Description

The claimed utility model relates to the field of ship equipment, namely to installations for obtaining (producing) a gas mixture with a high nitrogen content from atmospheric air, which is used to reduce the fire hazard when performing technological operations with combustible substances on ships.

The shipboard inert gas installation is designed for supply and periodic replenishment (filling) of aviation fuel tanks with nitrogen, which are located on each aircraft carrier ship or ships with a helipad. In addition, the inert gas system is designed for periodic nitrogen replenishment of aircraft or helicopter systems that are based on an aircraft carrier or ships with a helipad.

In particular, the present utility model can be applied to obtain high-pressure nitrogen with a low dew point for pressurizing fuel tanks and purging fuel lines on aircraft carriers.

The specific requirements for such inert gas systems are:

- minimum overall dimensions to ensure placement in confined spaces;

- arrangement on a single steel supporting frame of the equipment included in the installation;

- implementation of the compressor drive from the electric motor;

- the possibility of obtaining high-pressure nitrogen at the outlet of the plant up to 20 MPa;

- implementation of water cooling of heat-generating equipment;

- the possibility of automatic control of the technological process of obtaining gaseous nitrogen.

Known mobile nitrogen compressor station, containing the first and second compressors with diesel drives and a gas separation unit, while the output of the first compressor is connected to the inlet of the second compressor through the gas separation unit, the first compressor is made of a screw, and the second compressor is made of a multistage piston (RF patent No. 114490, IPC F04B 41/00, published 2012).

Known nitrogen generator containing a screw compressor with a drive in the form of a diesel engine, an air preparation system with a heater and a gas separation unit, while the air outlet of the compressor is connected to the inlet of the gas separation unit (RF patent No. 135,268, IPC B01D53 / 00, publication 2013).

Known nitrogen compressor station SDA-50/25, containing the first and second screw compressors with diesel drives, the first and second air preparation systems, the first and second gas separation units. In this case, the air outlet of the first compressor is connected to the air inlet of the first air preparation system, the air outlet of which is connected to the air inlet of the first gas separation unit. In addition, the air outlet of the second compressor is connected to the air inlet of the second air preparation system, the outlet of the first gas separation unit is connected to the first isolation valve, and the outlet of the second gas separation unit is connected to the second isolation valve (RF utility model patent No. 161848, IPC F04B 41/00 , published 2016).

Known mobile nitrogen compressor station containing a compressor, a power drive of the compressor, a power drive fuel system with a fuel tank and a gas separation unit in which the fuel tank is located outside the station under its frame. At the same time, the station contains a liquid cooling system for the compressor drive and a liquid cooling system for the compressor (patent for a useful model of the Russian Federation No. 123073, IPC F04B 41/00, publication 2012).

The disadvantage of the known devices is the use of diesel drives for compressors, the need for a supply of diesel fuel, the need to provide air supply for operation and cooling of diesel drives, which is limitedly applicable on ships, as it leads to an increase in overall dimensions, noise and complicates operation and maintenance.

Known automated compressor station, which includes a piston multistage high-pressure compressor with a drive, a compressed air drying and cleaning unit, a compressor cooling system, a drying unit cooling system, a compressor vibration isolation system and an automated control system, in which the compressor cooling system and the drying unit cooling system are double-circuit and each of them contains a closed liquid loop with non-freezing liquid for cooling directly the compressor or a drying unit, and a water-air heat exchanger with electric fans for cooling the liquid loop with atmospheric air (patent for a useful model of the Russian Federation No. 135015, IPC F04B 41/00, publication 2013 ).

The disadvantage of the known compressor station is that, despite the possibility of liquid cooling of the heat-generating equipment (compressor and drying unit), an ineffective water-air heat exchanger is provided in the cooling system, which has significantly larger overall dimensions compared to a water-to-water heat exchanger, and also requires direct contact with atmospheric cooling air, which is difficult to implement in ship installations, which, as a rule, are located in engine rooms.

The closest analogue of the proposed device is a nitrogen compressor unit, which includes a screw and piston compressors with drives from electric motors placed on a single frame, a control unit, an air preparation unit with a heater, a membrane gas separation unit, at the outlet of which a gas analyzer is installed, while the input of the preparation unit air is connected to the outlet of the first compressor, and the membrane gas separation unit is connected to the outlet of the air preparation unit, and the outlet of the membrane gas separation unit is connected by a pipeline through a shut-off and control valve with two parallel-connected containers for gaseous nitrogen located on the frame, one of which is through a shut-off control valve communicated with the inlet to the piston compressor and then through a filter with a high-pressure nitrogen outlet, and the second through a pressure reducing valve and a shut-off-control valve communicated with a low pressure nitrogen outlet (RF patent No. 180075, IPC F04B 41/00, public 2018).

The disadvantage of the known device is the lack of the possibility of water cooling of the heat-generating equipment (compressors) by means of a cooling unit with a fresh circuit, the removal of heat from which is carried out by an external coolant (seawater), which is preferable for ship equipment.

The objective of the proposed utility model is to expand the arsenal of technical means used for the production of high-pressure gaseous nitrogen.

The technical result consists in the implementation of the specified purpose and the creation of an efficient and easy-to-use design of the device used to obtain gaseous nitrogen from air.

The specified technical result is achieved by using a marine compressor plant for producing high-pressure gaseous nitrogen, which includes a screw compressor, an air preparation unit, a membrane gas separation unit, a piston compressor, a filter dryer and a liquid cooling system of compressors located in a single casing and connected in series with pipelines. a container for gaseous nitrogen is placed between the membrane gas separation unit and the piston compressor. The installation is characterized by the fact that the liquid cooling system of the compressors includes two circuits - an internal closed circuit with fresh water circulating in it, which provides cooling by means of heat exchange

heat-loaded elements of screw and reciprocating compressors, and an external circuit connected through nozzles made in the unit body to an external cooling source (seawater) for cooling fresh water circulating in the internal circuit.

The ship's inert gas system is designed to produce gaseous nitrogen from air by selective separation on polymeric membranes using two electrically driven compressors with a water cooling system.

FIG. 1 is a schematic diagram of a nitrogen compressor unit, FIG. 2 shows a front view of a nitrogen compressor unit, FIG. 3 - the same, top view.

The nitrogen compressor unit (see Fig. 1) includes a screw compressor 1, an air preparation unit 2, a membrane gas separation unit 3, a container for gaseous nitrogen 4, a controlled valve 5, a high-pressure piston compressor 6, a filter dryer 7. All elements of the unit are located in series and connected to each other, and the containers 4 are connected in parallel. To remove high-pressure product nitrogen, the unit is equipped with a branch pipe 8. To remove permeate, the nitrogen compressor unit is equipped with an outlet branch pipe 9. At the outlet of the membrane gas separation unit 3, to remove substandard nitrogen in the process of entering the mode, a branch pipe 10 is provided, the discharge to which is ensured by the operation of a shut-off and control valve 11 and a controlled valve 12. To control the gas mixture at the outlet of the membrane gas separation unit 3, a gas analyzer 13 is provided, for the automatic drainage of condensate from the air preparation unit 2, the nitrogen compressor unit is equipped with an outlet pipe 14.

To control the supply of high-pressure product nitrogen to the consumer, a shut-off and control valve 15 is installed at the outlet of the filter dryer 7 in front of the branch pipe 8. To control the dew point of product nitrogen, a dew point analyzer 16 is provided.

To cool the heat-loaded elements of screw and piston compressors, a cooling unit 17 is provided, consisting of an internal closed circuit with fresh water circulating in an internal closed circuit, and an external circuit connected through nozzles made in the installation body to an external cooling source (seawater). Water supply to the cooling unit 17 from an external cooling source (seawater) is provided through a branch pipe 18. Water is removed to an external cooling source (seawater) through a branch pipe 19.

A marine compressor plant for producing high-pressure gaseous nitrogen (see Fig. 2 and Fig. 3) contains a control unit 20 for monitoring the main parameters and automatic control of the plant, including an operator panel 21 that provides visualization and adjustment of the nitrogen compressor plant. All units and systems are connected by functional links and fixed on a single bearing frame 22.

Marine compressor installation for producing high-pressure gaseous nitrogen operates as follows.

The source air is compressed with the help of compressor 1 and under pressure is sequentially supplied to the air preparation unit 2, where it is cleaned from oil vapors, droplet moisture, solid particles and other harmful impurities, and the basic air parameters (pressure, temperature) are stabilized.

The removal of condensate from the filters included in the air preparation unit 2 is carried out automatically through condensate traps (not shown) and then to the outlet pipe 14.

From the air preparation unit 2, compressed air enters the inlet of the heater (not shown), in which it is heated to a temperature corresponding to the optimal operating mode of the membrane gas separation unit 3 (45-55 ° C). Maintaining the required temperature of the heater with an electric heating element is carried out using the control unit 20.

The cleaned and heated air is supplied to the membrane gas separation unit 3.

Passing through the membrane gas separation unit 3, compressed air is divided into two streams: an air stream with a high oxygen content (permeate) at the outlet of the branch pipe 9 and an air stream enriched in nitrogen (retentate) at the outlet of the branch pipe 10. The separation of gases occurs due to different coefficients of nitrogen permeability and oxygen through the polymer membrane of the gas separation unit 3. The driving force of separation is the difference in the partial pressures of gases on the membrane.

The basic operating parameters are set from the operator panel 21, located in the control unit 20, and can be changed if necessary.

At the outlet of the membrane gas separation unit 3, there is a shut-off and control valve 11, a controlled valve 12 and a branch pipe 10 for discharging substandard nitrogen. At the stage of reaching the operating mode, the gas mixture of nitrogen is controlled by the gas analyzer 13 and, if the target nitrogen concentration is not reached, it is discharged through the controlled valve 12 and the discharge pipe 10. When the target nitrogen concentration, also controlled by the gas analyzer 13, is reached, the valve 12 closes, the shut-off valve 11 opens and gaseous nitrogen with a given concentration enters the tank 4.

From the outlet manifold of the tanks 4, gaseous nitrogen through valve 5 enters the inlet of the booster piston compressor 6 and then through the filter drier 7 and the shut-off valve 15 to the outlet 8.

The control unit 20 (Fig. 2, 3) monitors the main parameters, visualization on the operator panel 21 and automatic control of the installation.

The ship's inert gas system allows solving gas separation problems with a capacity of up to 250 nm ³ / h for the target product with a nitrogen purity of 95 to 99.5%, at a pressure of up to 35 MPa, with a dew point of up to minus 60 ° C.

The present utility model provides the creation of an efficient and easy-to-use design of a device used to obtain gaseous nitrogen from air, thereby expanding the arsenal of technical means used for the production of gaseous nitrogen used on ships and vessels and in other industries.

Claims (1)

Marine compressor plant for high-pressure gaseous nitrogen production, including a screw compressor, an air preparation unit, a membrane gas separation unit, a piston compressor, a filter-dryer and a liquid cooling system for compressors located in a single housing and connected in series with pipelines, between the membrane gas separation unit and a reciprocating compressor contains a container for gaseous nitrogen, characterized in that the liquid cooling system of the compressors includes two circuits - an internal closed circuit with fresh water circulating in it, which, through heat exchange, provides cooling of heat-loaded elements of screw and reciprocating compressors, and an external circuit connected through nozzles, installed in the casing of the unit, to an external source of cooling (sea water) for the possibility of cooling fresh water circulating in the internal circuit.

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