CS215602B1 - Method of self-controlled withdrawal of water vapour condensate - Google Patents

Description

The invention relates to a process for the self-regulating discharge of water vapor condensate.

In municipal and industrial practice, especially in the chemical industry, apparatuses in which heat is transferred are often used. The heat transfer medium is most often water vapor, which in the heating space of the aperate transfers its latent heat and after cooling Rpd condenses the dew point. The resulting condensate is usually collected and returned as feed water to the steam generators. It is unacceptable for the heat exchanger to operate with the vapor permeability, i. with incomplete condensation of heating steam.

That is why the first condensate drainage systems with a labyrinth or orifice have been abandoned, which were able to limit but not prevent vapor permeability. · Most of today's regulation systems discharge condensate at boiling point. Adjustable regulating z

215 602 organs are called condensate traps and are controlled by pulses from one or more quantities ·

For example, regulating the condensate drain by means of float condensate traps uses the difference in mass of the gaseous and liquid phases to move the float, and this movement then provides a mechanical impulse to open the outlet from the heat exchanger space to collect condensate.

This system discharges the condensate at the temperature. Another example is a control system regulating the condensate discharge at the boiling point and even counting with the penetration of heating steam. It is based on the operation of the so-called thermodynamic trap, which uses different hydrodynamic properties of steam and condensate in combination and the pressure effect of the penetrated steam to mechanically shut off the condensate drain. Some systems discharge condensate below the boiling point. The control pulse is a different temperature of the Bourdon pen not filled with low boiling liquid. The temperature of the tongue and thus the pressure in the tongue that mechanically shut off the condensate drain are influenced by another characteristic of the heat transfer to the tongue from steam or condensate. Such types of regulators are not thermostatic.

A common disadvantage of all these solutions is the complexity with the problem of mechanical design, which cause deviations from the ideal operation and cause the penetration of heating steam into the condensate collection, even if the principle does not even allow for this penetration. Most of these systems expand the condensate to the boiling point at the pressure in the heating system. If the condensate collection is under a pressure of up to 0.2 MPa, the expansion from the heating system pressure of 0.5 MPa produces about 7 weight percent of the gas phase in the condensate collection. Expansion from an underpressure heating system of about 1 MPa generates 13% of the gaseous phase at expansion to a pressure of 0.2 MPa in the condensate collection. When the condensate is drained from the high pressure condensation system, the px of the gaseous phase is greater than that of the gaseous phase. This gas phase, created by expansion, together with the occasional vapor phase leakage from the heating spaces of the pressurized condensate collecting chamber, requires a large oversizing of the piping lines downstream of the condensate drain and makes the entire heating systems vulnerable to continuous steam discharge.

It has now been found that self-regulation of the water vapor condensate drain can be achieved by eliminating or substantially reducing all the disadvantages of the prior art condensate drain systems according to the invention, wherein the condensate is cooled before boiling below boiling at booster pressure, the condensate throttling resistance is controlled by the temperature e by printing the condensate before the throttling, and the temperature and pressure before the throttling is controlled by the hydraulic resistance.

The method of self-regulating water vapor condensate discharge according to the invention has several advantages over the prior art systems. It makes use of the heat that escapes today and hot condensate, and on average more than 10% savings in heating energy can be expected in the most widespread medium-pressure systems. It also prevents the penetration, in particular of the incision, into the condensate collection. When measured on a small appliance, this penetration was up to 10% of the amount of condensate. It allows to dimension condensate collections much more rationally than hitherto. It transmits heat losses from today's heating steam with condensate cooling. By reducing the condensate collection dimensions, it further reduces losses.

215 602

In the condensate drain, a self-regulating equilibrium was created. The condensate was pressurized before throttling

And was cooled to 123-6 ° C. The hydraulic resistance at throttling was 0.42 MPa.

The boiling point at the pre-throttling pressure; 0.52 MPa, corresponds to a temperature of 153.4 ° C. The system discharged 12.6 kg of condensate per hour, representing 10% of the consumption savings measured for the same system, but controlled by a float trap.

Example 2

In a steam heating system with a maximum pressure of 1.6 MPa, the regulator maintained a heating pressure of 0.5 MPa. The condensate at 300 kg / h was cooled to 110-150 [deg.] C. and a pressure of 0.53 MPa prior to throttling. The hydraulic throttling resistance was 0.4 MPa. A pressure of 0.53 MPa corresponds to a boiling point of 154.2 ° C. There was a reduction of at least 27 kg of steam per hour compared to the consumption that the same float trap system would show.

Example 3

In a steam heated system of 0.7 MPa with a boiling point of 165 ° C and a maximum pressure of 1.6 MPa, the product is distilled at 140 ° C. The water vapor condensate from the distillation system passes to the feed preheating system where it is cooled down to 110 ° C. Prior to throttling, the condensate had a pressure of 0.75 MPa. The hydraulic throttling resistance was 0.65 MPa. The condensate at 430 kg / h did not induce mating of the condensate proceedings. Compared to the consumption with the existing condensate drainage regulations, a saving of at least 47 kg of steam per hour has been saved, unless heat for heating the spraying is considered necessary. If necessary, we save 80 kg of steam per hour.

Example 4

Condensate feed preheating from the distillation system was excluded from the system described in Example 3. The equilibrium was established at a cooled condensate temperature prior to throttling of 150-5 ° C. For steam consumption of 430 kg / h, the pressure of the heating spring had to be increased to 0.8 MPa. The condensate pressure before throttling reached 0.85 MPa and the condensate proceedings began to mate. The temperature corresponding to the boiling point at the pressure before throttling is 173 ° C. The hydraulic resistance at throttling reached 0.75 MPa. Compared to the existing condensate drainage systems, the system saved 14 kg of steam per hour.

Claims (1)

A method of self-regulating water vapor condensate drainage from expansion condensation systems, characterized in that the condensate is cooled below the boiling point below the boiling point at the pre-throttling pressure, wherein the hydraulic resistance at the condensate throttling is controlled by the is controlled by hydraulic resistance.