Synergic-purification all-heat-recovery combined heat and power generation system

Abstract

The invention relates to a synergic-purification all-heat-recovery combined heat and power generation system which comprises a heat power plant waste heat utilization system and a heating station, wherein the heat power plant waste heat utilization system is connected with the heating station through a heat supply network return water supply pipeline; and the heat power plant waste heat utilization system comprises an air humidifier, a gas-water thermal tower, a water-to-water heat exchanger, an absorption heat pump, a steam-to-water heat exchanger and a steam condenser. In the heat power plant, the air is humidified to enhance the dew-point temperature of flue gas; the return water temperature is further lowered in the heating station, so that the heat supply network return water is lowered to 10 DEG C and even lower; and the two measures are integrated to recover all the flue gas waste heat and dead steam waste head. Meanwhile, a dosing port is arranged on a flue gas waste heat recovery spray water path, so that the flue gas is cleaned in the waste heat recovery process, thereby achieving favorable denitrification effects. The acidic condensation water is neutralized to achieve the discharge standard, thereby integrating the functions of waste heat recovery and flue gas purification. The synergic-purification all-heat-recovery combined heat and power generation system is suitable for combustible gas heat power plants, biomass heat power plants and the like, and can be further popularized to coal-burning heat power plants and boilers.

Description

technical field [0001] The invention relates to a cogeneration system of cogeneration of heat and power with synergistic purification and total heat recovery, which belongs to the field of energy technology. Background technique [0002] For district heating, a typical way of using natural gas is gas-steam combined cycle heat and power cogeneration for heating. In recent years, the gas-steam combined cycle heat and power cogeneration technology has been greatly developed, but there is still a lot of room for improvement in the efficiency of the heat source. At the same time, the pressure of environmental protection has also put forward higher requirements for the purification of system exhaust. To improve efficiency, it is necessary to consider the use of the latent heat in the flue gas and the condensation heat discharged from the steam turbine. Because the return water temperature of the urban heating network is high, it is difficult to provide low-temperature refrigerant ...

AI Technical Summary

Problems solved by technology

In recent years, gas-steam combined cycle heat and power cogeneration technology has been greatly developed, but there is still a lot of room for improvement in the efficiency of heat sources. At the same time, environmental protection pressure has also put forward higher requirements for the purification of system exhaust

To improve efficiency, it is necessary to consider the use of the latent heat in the flue gas and the condensation heat discharged from the steam turbine. Because the return water temperature of the urban heating network is high, it is difficult to provide low-temperature refrigerant to recover the two kinds of waste heat when returning to the thermal power plant, resulting in huge losses. waste of heat

[0003] Aiming at this problem, the existing technology proposes a new type of energy supply system based on gas-steam combined cycle heat and power cogeneration. In the thermal power plant, the mode of integrating the partition flue gas heat exchanger and the heat pump is designed to recover the waste steam waste heat and flue gas. The gas waste heat process can recover part of the waste heat, but there are still two problems to be solved in this system. One is that the return water temperature of the heating network is still high, and the waste heat of flue gas and exhaust steam cannot be fully recovered when returning to the thermal power plant. The recovery of flue gas waste heat and exhausted steam waste heat is a pair of contradictions. If exhausted steam waste heat is recovered, flue gas waste heat cannot be fully recovered, and vice versa. Therefore, how to coordinate the relationship between flue gas waste heat and exhausted steam waste heat to achieve two The complete recovery of part of the waste heat has become a difficult point; the second is that the flue gas waste heat recovery heat exchanger in the thermal power plant adopts the indirect heat exchange method, which has key problems such as poor heat transfer effect, large volume, large flue gas side resistance, and easy corrosion

In the existing technology, a gas-steam combined cycle central heating device and heating method are designed, and the end uses an absorption heat exchange unit to reduce the return water temperature (about 30°C), which is improved compared with the existing technology. However, the return water at this temperature is returned to the thermal power plant to recover the waste heat of flue gas and waste steam, and the above two existing technologies are all aimed at the recovery and utilization of waste heat, and have not comprehensively considered how to reduce emissions

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