A flue gas waste heat deep recovery system

Abstract

The invention relates to a deep recovery system for waste heat of flue gas. The recovery system includes a vertical thin-walled hollow cylindrical casing, and a rotating core coaxially arranged on the upper part of the casing and capable of rotating relative to its own central axis is arranged on the The baffle, the baffle plate, the spray device, and the water-to-water heat exchanger connected with the water inlet and outlet of the spray device in the shell and through the central axis of the shell and the rotating core; the rotating core is vertical Type thick-walled hollow cylinder, the longitudinal section of the side wall of the rotor is honeycomb-shaped, and filled with hygroscopic material inside; the partition divides the inner space of the shell and the rotor into two parts: the air flow channel and the smoke flow channel; A plurality of baffles are arranged respectively between the top of the housing and the top of the rotating core, between the top of the rotating core on the side of the smoke flow channel and the top of the partition, and between the bottom of the rotating core on the side of the air flow channel and the top of the partition. Between the plates, and between the bottom of the rotating core on the side of the flue gas flow channel and the casing; the spray device is arranged in the flue gas flow path at the lower part of the casing.

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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