Flue gas waste heat deep recovery system

Abstract

The invention relates to a flue gas waste heat deep recovery system. The flue gas waste heat deep recovery system comprises a vertical type thin-walled hollow barrel-shaped shell, a rotating core which is disposed coaxially on the upper part of the shell and can rotate relative to the self central axis, a separation plate which is arranged in the shell and passes through the central axis of the shell and the rotating core, a plurality of baffles, a spraying device and a plate heat exchanger connected to a water inlet and a water outlet of a heat releasing unit and a spraying device; the rotating core is in a vertical type thin-walled hollow barrel shape, the longitudinal section of the side wall of the rotating core is in a honeycomb shape, and the rotating core is filled with a hygroscopic material; the separation plate divides the inner space of the shell and the rotating core into two parts of an air flow passage and a flue gas flow passage; the multiple baffles are separately disposed between the top of the shell and the top of the rotating core, between the top, on one side of the flue gas flow passage, of the rotating core and the top of the partition plate, between the bottom, on one side of the air flow passage, of the rotating core and the baffles and between the bottom, on one side of the flue gas flow passage, of the rotating core and the shell; and the spraying device is disposed in the flue gas flow passage in the lower part of the shell.

Description

technical field [0001] The invention belongs to the technical fields of heating, ventilating and air-conditioning and urban heating, and in particular relates to a deep recovery system for flue gas waste heat. Background technique [0002] As a clean and efficient primary energy, the demand for natural gas continues to grow in my country. In 2016, the national natural gas consumption has reached 205.8 billion cubic meters, a year-on-year increase of 6.6%. At the same time, due to the implementation of the "coal-to-gas" policy in the north, natural gas has become the main energy source for heating in winter in the north. At present, gas-fired boilers are the main way of heating in winter, and the exhaust gas temperature of natural gas is generally 80-120°C, which has huge potential for waste heat recovery. Moreover, the thermal efficiency of the boiler gradually increases as the exhaust gas temperature decreases. When the exhaust gas temperature drops to 30-55°C, it enters ...

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Problems solved by technology

[0003] However, since the dew point temperature of the flue gas exhaust heat recovery system commonly used in gas-fired boilers is close to the return water temperature of the heating network water, the return water of the heating network cannot effectively absorb the latent heat in the flue gas, and there is still a large amount of heat in the exhaust gas. part of the energy is wasted

However, in the existing deep waste heat recovery system, the use of air preheater or economizer has the problem of insufficient latent heat recovery or the phase change mismatch between the flue gas and the air on both sides.

In addition, some scholars have suggested that the main problem of using water as the medium for heat exchange between flue gas and air is the mismatch of energy conversion caused by the nonlinearity of the saturation line of air.

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