PG heat exchangers

PG heat exchangers

In the course of gas pressure regulation, in consequence of gas expansion, a considerable gas temperature drop takes place. This rapid temperature drop may result frosting and even freezing of regulating units, especially of the remote control units controlling the pressure regulators mounted in high pressure regulation stations. In order to maintain failure-free action of gas pressure regulating stations, it is necessary to increase gas temperature prior to regulation to assure a gas temperature within +5 to + 10°C after regulation. One of the most commonly used methods of heating natural gas in pressure regulating stations is the use of heat exchangers with hot fluid used as the heating medium.

Heating of gas

Gas heating is a result of heat transfer from the heating medium and the gas flowing through the tube bundle (coil). The heating medium temperature in the heat exchanger is controlled depending on gas temperature downstrearn the regulating u nit. Internal mounting of the heating fluid circulation pump improves heat transfer and control accuracy. The circulation pump provides much more efficient use of heat exchanging surface, thus allowing for considerable reduction of heating medium tubes diameters.

Parameters of gas heating units

Inlet gas pressure (design): standard-1.6; 2.0; 2.5; 7.0; 11.0 MPa

Heating medium:

• water
• design pressure in the heating section:
  • standard: 0.6,7.0 MPa
• inlet temperature +90°,
• outlet temperature +70°.

Safety devices

Heat exchangers have got a pipe connector, located on the Shell side jacket and used to connect safety devices. In case of tube damage, the gas may be immediately vented into the atmosphere, either via a safety head or safety valve. In standard applications, the pipe connector is designed with a flat flange for PN 16 pressure. When the shell side is designed to gas pressure, safety is provided by an RMG 790 valve, set for the maximal pressure of the heating fluid in the boiler system. The escaping gas is captured in the shell side of the heat exchanger.

Construction and the principle of action

Gas heating, in the basic configuration, have a coil, welded into a mesh bottom, localised between the tube side flange and the heating medium jacket flange. These parts may, at any time, be individually replaced. Cold gas flows through the connector pipe and the inlet into the coil. After being heated, gas flows through the tube side the outlet connector into the pipeline system. The heating medium flows through a number of baffles, leading it round the coil. The tube bundles are welded into a mesh bottom, designed (calculated) appropriately to the gas pressure.

Al! the tubes have 2 mm walls, with 1 mm allowance for corrosion. The tube side of the heat exchanger features connector pipes for draining condensate. The mesh bottom has got a drain valve to drain heating medium, left within the space below the outlet connector.

Show Catalogue Gas Pressure Installations

GAZOMET Sp. z o.o. manufactures pressure vessels, following the assurance system of the 97/23/EEC Directive. There GAZOMET Sp. z o.o. is entitled to mark the manufactured equipment with the  CE  symbol.