A device for determining the dew point in gases

 

(57) Abstract:

Usage: in measurement technology, in particular, in the device for determining the dew point temperature. The inventive device includes a chiller-heater 1, the control unit status condensing surface 2, meter 3, the temperature of the condensation surface 4, the first analog-to-digital Converter 5, the second analog-to-digital Converter 6, the generator quantizing pulses 7, the first register 8, the second register 9, the subtraction unit 10, the level detector 11, the key 12, the recording unit 13. When the device is in the first register is written last value measurements, and in the second case of the previous one. If the difference between the two values obtained in the subtraction unit reaches a predetermined level, the corresponding signal is sent to the recording unit 13, which detects the temperature of the dew point. 2 Il.

The present invention relates to measuring technique and can be used mainly in the natural gas industry to measure the quality of natural gas treatment, gas processing, oil refining, chemical industries.

Known devices for bathing rod, washed analyzed by gas, with a fixed length sensors, cooled at one end and heated with the other. At the core is formed of the condensation surface with a constant time and the length of the temperature gradient. Border condensation corresponding to the designated dew points are determined visually, values are calculated temperatures at the boundaries of condensation, and these temperature read by the temperature of the dew points [1]

The specified technical solution to apply to determine the dew point decelerationratio because of the unclear boundaries of condensation on the web. In addition, for the accuracy of their determination requires a high qualification of the operator.

The closest technical solution is a device for determining the dew point in gases containing cooler heater periodically heating and cooling the condensing surface, measuring the temperature of the condensation surface, the control unit status condensing surface and the recording unit.

The definition of dew points using the specified device is as follows: in the process of cooling the condensing surface, the temperature of which the continuous is sacia vapor of the component being controlled gas what is registered by the control unit of the state of the condensing surface. The latter is most often realized by the photo method, which consists in the fact that aimed at a polished condensing surface a beam of light when the condensation is dissipated. On the path of the reflected light beam is set to the photodetector, marking a decrease of the brightness in the condensation.

Known variants of this device, for example, the installation of a sensor that responds to ambient light; the use of frosted condensing surface, reflecting the capacity of which increases with condensation.

The appearance of the signal at the output of control unit status condensing surface causes the actuation of the registering unit, the fixing temperature of the condensing surface at this point, as the dew point.

As a recording unit used: dial gauge, continuously indicating the temperature of the condensing surface, together with the bulb lights when the dew-point, digital indicators, in memory which records the value of the dew point temperature, tsifropechatayuschee device, etc., authorized the surface and the challenge of finding a few dew points in mixtures of gases.

High sensitivity to contamination due to the fact that the appearance of the pollution and the appearance of drops of condensate on the condensing surface have the same effect on the control unit status condensing surface.

For example, if the control status polished condensing surface is the photo method, the criterion for determining the dew point is the degree of scattering of light rays when drops of condensation on the surface, but the surface also causes scattering of light that causes the error.

Strong enough pollution causes failure of the device.

Similar reason complicates the identification of multiple dew points in mixtures of gases.

When determining, for example, the second dew-point of the condensate layer, the component that caused the first dew point prevents as well as pollution condensing surface.

For example, if the photo method, the degree of light scattering caused by the deposition of a first layer of condensate depends on many factors, including the temperature difference between the first and second dew point and therefore uniquely identify the second t is O.

The basis of the invention the task is to create such a device for determining two dew points in which the new execution units and their location would provide reliable registration of these points.

This task is solved in that in the known technical solution containing the condensation surface, equipped with a cooler, heater, measuring the temperature of the condensation surface, the control unit status condensing surface and the recording unit, advanced key is entered, two analog-to-digital Converter, the level detector two register, the subtraction unit and the generator quantizing pulses. The yield of the latter is connected to control inputs of the first and second registers, the information input of the second register connected to the output of the first register, the information input of the first register is connected to the output of the second analog-to-digital Converter, whose input is connected to the output of control unit status condensing surface, the input of the first analog to digital Converter coupled to the output of measuring the temperature of the condensation surface, and the output information input key and the generator input quantizing pulses, Dora level, the output of which is connected with the control input of the key, the output of which is connected to the input of the recording unit.

The subtraction unit determines the difference between the illumination of the photodetector when the temperature of the condensation surface to the preset value, the reliability determination of the dew points: mainly two closely spaced points.

The introduction of two registers makes it possible to identify the difference between the light condensing surface at a time corresponding to the two successive pulses from the generator quantizing pulses.

Generator quantizing pulses provides control registers, normalizing measuring the difference in light when the temperature of the condensation surface by a specified amount. These new design solutions to enhance the reliability of the registration of the dew point.

In Fig. 1 shows a diagram of the device of Fig. 2 according to the illumination of the photodetector and its derivative of the temperature.

The device includes a chiller-heater 1, the control unit status condensing surface 2, measuring the temperature of the condensing surface 3, the condensing surface 4.l 6, generator quantizing pulses 7, the first register 8, the second register 9, the subtraction unit 10, the level detector 11, the key 12, a recording unit 13, and the input of the generator 7 is connected to the output of the first inverter 5, and the two outputs of the generator 7 with the control inputs of the first 8 and second 9 registers, respectively. The information input of the second register 9 is connected to the output of the register 8 and the output of each register is connected with the corresponding output of the subtractor, the output of which is connected to the level detector 11.

The device works in the following way:

After completion of the next operation cycle of the condensation surface 4 in the heat reaches a maximum temperature in excess of a reasonable range of the measured dew points, the chiller-heater is switched to the cooling mode.

The control unit status condensing surface 2 in the measurement process continuously monitors the condensation surface 4. The control can be carried out, for example, the photo method, in which the measured reflectivity condensing surface, decreasing with the loss of the condensate. The signal control unit condensing surface 2 (decreasing when the issue is for the convenience of further processing. With him the signal is sent to the first register 8, and the entry in the register is carried out each time at the time of receipt of the pulse quantizing pulses 7.

The temperature of the condensing surface 4 is measured by measuring its temperature 3, is converted into digital form by the first analog-to-digital Converter 5, to the input of the generator quantizing pulses 7 generating pulses when the temperature of the condensation surface at a given value of T

The output of the first register 8 is connected to the input of the second register 9, which carries the recording signal output from the first register by the same pulse generator quantizing pulses, and the first register. The result in the first register is written the last value of the measurement made by the control unit status condensing surface 2, and in the second case the previous one, which was recorded at a higher temperature of the condensation surface 4.

Upon reaching the input signal of the subtraction unit 10 preset level, the level detector 11, the key 12 transmits a signal corresponding to the temperature of the condensing surface from the output of analog-to-digital Converter titsa in the heating mode condensing surface and the cycle repeats.

In Fig. 2 shows the dependence of the illumination of the photodetector F. the temperature of the condensation surface T (monitoring the status of the condensing surface is the photo method).

During cooling from the maximum temperature of the illumination of the photodetector in the beginning doesn't change (section 1), then there is condensation on the condensing surface, while it is "cloudy", the light beam scatters the light falls (section 2).

Upon further condensation occurs coalescence (section 3), accompanied by increased light, which is then stabilized (section 4).

When measuring the second dew-point picture is similar (section 5).

Obviously, the presence of contamination on the condensation surface, the scattering of incident light by the photodetector is perceived as reducing light f, i.e., "shift" down the considered curve. If the definition of dew point is a device prototype at a fixed level of illumination of the photodetector f, for small dirt this dramatically reduces the accuracy of measurements, and at large causes the failure. To measure the second dew point exacerbated postfeminist affect both specific temperatures dew points and pollution, and the value of the temperature difference between two points of dew.

In the proposed device difficulties resolved: the derivative of a constant is zero, the criterion for fixing the dew point is the abrupt change of illumination f, which occurs only close to the dew point, causing a sufficient level derived.

The accuracy of the instrument, which is used by the invention, is 0.5oC dew point.

Loss of hydrocarbon condensate on a single installation of gas separation in error in the determination of the dew point in 2-3oC up to 3-5 g/cu m, which is at the output of 1 million cubic meters/day 3-5 tons/day.

A device for determining the dew point in gases containing the condensing surface, equipped with a chiller-heater, measuring the temperature of the condensation surface, the control unit status condensing surface and the recording unit, wherein it is further provided with a key, two analog-to-digital converters, level detector, two registers, the subtraction unit and generator quantizing pulses, and the output of the latter with what hodom first register, the information input of the first register is connected to the output of the second analog-to-digital Converter, whose input is connected to the output of control unit status condensing surface, the input of the first analog-to-digital Converter coupled to the output of measuring the temperature of the condensation surface, and the output information input key and the generator input quantizing pulses, two inputs of the subtraction unit is connected to the outputs of the first and second registers, respectively, and the output to the input of the level detector, the output of which is connected with the control input of the key, the output of which is connected to the input of the recording unit.

 

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