Cold source temperature control method and device for flue gas waste heat recovery equipment

Abstract

The invention relates to a cold source temperature control method of a flue gas waste heat recovery device. The method mainly comprises the steps of parameter collection, data processing, fuzzy reasoning, controlled quantity outputting, controlling execution and the like. The method specifically comprises the steps of: calculating a temperature error e and a temperature difference change ec with a reference set temperature by collecting parameters such as cold water temperature, hot water temperature, temperature of a mixed water tank, heat exchange wall temperature and exit gas temperature in the flue gas waste heat recovery device; and then, obtaining control parameters by fuzzy reasoning, and adjusting the cold source temperature by controlling a cold source water electric adjusting executor and a flowback water electric adjusting executor through the parameters. According to the invention, with the adoption of an advanced fuzzy predicting method, deviation, size change and direction as well as time relationship of the controlled volume are effectively pre-compensated according to a fuzzy rule established by real time identification of the system, so that short of adjustment or over-adjustment is prevented, the influence to the performance of the control system due to great inertia and large hysteresis in the controlled process is improved, and the control quality is improved.

Description

technical field

[0001] The invention relates to the field of waste heat recovery, and relates to a cold source temperature control method and device for flue gas waste heat recovery equipment that can automatically track and clamp the lowest wall temperature of a single-stage or multi-stage cold end to be above the acid dew point and within a fixed value range. Background technique

[0002] The exhaust gas temperature of the factory design and operation of the boiler accounts for a large proportion of the heat loss of the boiler. Making full use of the waste heat of the exhaust gas not only meets the requirements of energy conservation and emission reduction policies, but also reduces the energy cost of the enterprise at the same time.

[0003] At present, flue gas waste heat utilization equipment is gradually being commercialized. Waste heat technology in flue gas can be divided into direct heat exchange and indirect heat exchange.

[0004] (1) The direct heat exchange rep...

Examples

Embodiment Construction

[0055] In order to facilitate the understanding of the present invention, an embodiment is given in conjunction with the accompanying drawings to further describe the present invention.

[0056] Step 1: Parameter collection. The temperature sensor installed in the heat exchanger will measure the temperature of cold water in the heat exchanger, hot water temperature, cold source water temperature in the mixing water tank, heat exchange wall temperature of the heat exchanger, and flue gas temperature. Five parameters are collected;

[0057] Step 2: The data unit calculates the temperature error e and the temperature difference change ec according to the parameters collected in step 1, and sends the temperature error e and the temperature difference change ec to the fuzzy controller, and the temperature error e and the temperature difference change ec The relational formula is: e(k)=r(k)-y(k)

[0058] ec(k)=e(k)-e(k-1)

[0059] The symbols in the formula have the same meaning a...

technical field

[0001] The invention relates to the field of waste heat recovery, and relates to a cold source temperature control method and device for flue gas waste heat recovery equipment that can automatically track and clamp the lowest wall temperature of a single-stage or multi-stage cold end to be above the acid dew point and within a fixed value range. Background technique

[0002] The exhaust gas temperature of the factory design and operation of the boiler accounts for a large proportion of the heat loss of the boiler. Making full use of the waste heat of the exhaust gas not only meets the requirements of energy conservation and emission reduction policies, but also reduces the energy cost of the enterprise at the same time.

[0003] At present, flue gas waste heat utilization equipment is gradually being commercialized. Waste heat technology in flue gas can be divided into direct heat exchange and indirect heat exchange.

[0004] (1) The direct heat exchange rep...

Examples

Embodiment Construction

[0055] In order to facilitate the understanding of the present invention, an embodiment is given in conjunction with the accompanying drawings to further describe the present invention.

[0056] Step 1: Parameter collection. The temperature sensor installed in the heat exchanger will measure the temperature of cold water in the heat exchanger, hot water temperature, cold source water temperature in the mixing water tank, heat exchange wall temperature of the heat exchanger, and flue gas temperature. Five parameters are collected;

[0057] Step 2: The data unit calculates the temperature error e and the temperature difference change ec according to the parameters collected in step 1, and sends the temperature error e and the temperature difference change ec to the fuzzy controller, and the temperature error e and the temperature difference change ec The relational formula is: e(k)=r(k)-y(k)

[0058] ec(k)=e(k)-e(k-1)

[0059] The symbols in the formula have the same meaning a...

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