Flue gas waste heat recovery unit

Abstract

The invention relates to a flue gas waste heat recovery unit which comprises a flue gas unit, a generator unit, a condenser unit, an absorber unit, a water return pipe and a water supply pipe. The flue gas unit is sequentially connected with the generator unit, the condenser unit and the absorber unit to form a flue gas heat exchanging path; the outlet of the generator unit is connected with the inlet of a solution-to-solution heat exchanger, the outlet of the absorber unit is divided into two paths: one path is merged with the outlet of the solution-to-solution heat exchanger to be connected with the inlet of a solution-to-water heat exchanger through a solution spray pump, the outlet of the solution-to-water heat exchanger is connected with a solution spray mechanism in the absorber unit, the other path is connected with the inlet of a solution-to-solution heat exchanger through a solution circulating pump, and the outlet of the solution-to-solution heat exchanger is connected with a dilute solution spray mechanism through the generator unit so as to form a solution heat exchanging and circulating loop; the outlet of the condenser unit is connected with the inlet of a water-to-water heat exchanger through a condense water spray pump, the outlet of the water-to-water heat exchanger is connected with a condense water spray mechanism through the condenser unit to form a condense water heat exchanging and circulating loop; the water return pipe is connected with a water-to-water heat exchanger unit and the inlet of a solution-to-water heat exchanger, and the water supply pipe is connected with the water-to-water heat exchanger and the inlet of the solution-to-water heat exchanger.

Description

technical field [0001] The invention relates to a heat supply device, in particular to a flue gas waste heat recovery device capable of recovering water vapor and heat in wet flue gas formed by burning natural gas, oil and other fuels. Background technique [0002] Fuels such as natural gas and oil have a high hydrogen content, so the flue gas emitted after combustion contains a large amount of water vapor. For example, in the flue gas of a natural gas boiler, the volume component of water vapor is close to 20%, which is the main carrier of the heat of the flue gas. According to statistics per 1Nm 3 Natural gas can produce 1.55kg of water vapor, and the latent heat is about 3600kJ / Nm 3 , accounting for about 10% of the low calorific value of natural gas. Therefore, the recovery of this part of water vapor and its heat (mainly latent heat) is economically meaningful. [0003] The invention patent with the publication number CN1414288 discloses a heat supply device for rec...

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Problems solved by technology

However, this patent uses the heat of the high-temperature section of the flue gas as the driving heat source of the generator, and the flue gas temperature is affected by the operating conditions of its front-end equipment (such as a boiler), and fluctuates greatly. When the flue gas temperature is low, the solution cannot be effectively obtained. Concentration, the purpose of effectively recovering waste heat cannot be achieved, so this patent is only applicable to occasions where the exhaust gas temperature is relatively high and stable

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