Boiler Waster Heat Comprehensive Utilization
The working principle of the absorption heat pump technology
Lithium bromide absorption heat pump is composed of heat removal machine, concentrator, heater and reheater. The heat pump is driven by steam heat. The lithium bromide solution is as absorbent and water as refrigerant. It takes advantage of low water boiling point in low pressure and vacuum state to extract the low grade waste heat to make high grade water by recycling transformation. The high grade water is used for heating.
Application & Ecnomic Return
■ 16th Mar,2011 Applied on central heating project of waste heat recovery on 9、10# unit of Guodian Datong Second Power Plant.
■ 25th Dec,2011 & 10th Oct,2012 Applied on 1、2# unit of Guodian Dongsheng Thermal Power Co.,Ltd respectively.
According to six months of the heating period each year, the reclaimed exhaust steam and waste heat was 193.96*10^4GJ, and reducing CO2 emission 0.216million tons, reducing SO2 4100 tons, saving standard coal 72710 tons, saving fuel cost about 16.69 million CNY. Annual power supply coal consumption is reduced 21.46 g/kwh. 2.77 million m² of new heating area can be increased. 56.79 million CNY of heating fee can be increased.
■ 15th Nov,2012 Applied on 1、2# unit of Guodian Changzhi Thermal Power Co., Ltd.
In the condition of minimum 240MW power load in winter and total heating supply is 520.3MW, the reclaimed heat was 126MW/146.97*10^4GJ, saving 50100 tons standard coal. The new increase heating area is 287.8*104 m². About 0.16 million tons CO2 and 3100 tons SO2 was reduced.
High efficiency gas/waste heat exchanger
■ Reduce exhaust smoke temperature about 30℃ to 50℃
■ For heating, the recovery heat of flue gas is nearly equal to the heating amount.
■ When heating the condensate water, the coal consumption of power generation can be reduced about 2.4~3.5g/kWh. According to the local coal price and heat price, investment return period is generally less than 3 years
Introduce of H-type fin
H-type finned tube is mainly installed on heat exchange equipment( air heater, economizer, waste heat boiler) of power plant boiler, industrial boiler, and marine or stationary diesel units to recover exhaust waste heat, as well as waste heat recovery equipment in the technological process of chemical or oil industry. This tube can suit for most equipment fuel, no matter coal, heavy oil, fuel oil or gas.
H-type finned tube structure: H-type finned tube, double H-type finned tube
H-type finned economizer is similar to cast iron economizer of low pressure boiler. It can meet the design requirements of compact structure of the tail. Its arrangement of heating surface is six to nine times to the light tube economizer of same diameter and length. It accounts for the space is 50% to 60% of the light tube economizer. This design of compact tail is not only saving the tubular product, but also saving cost of the design and installation of bearing structure.
H-type finned economizer is arranged in the column arrangement. The fins form a channel naturally which has the superiorities in preventing contamination and ash deposition to the economizer, keeping heat transfer performance of the tube coil, and compared with other expanded-heating surface type economizer, the flu gas resistance is reduced. Under the same heat load and smoke speed, the metal weight of H-type finned economizer is only 60% of the light tube economizer and pressure reduce is only half to the light tube economizer.
The channel which formed by H-type fins make good performance of steam blowing, due to the straight channel can prevent steam spreading on both sides. For spiral fin economizer and heat pipe air preheater, the biggest problem is heavy ash congestion, H-type fin economizer is a ideal substitute for it. Cantilever beam structure can make natural vibration with the air vortex which can reduce the dust pollution and prevent the economizer abrasion, thus avoiding high loss of boiler shutdown and reducing maintenance cost.
Advantage of H-type finned economizer
■ Compact structure, light quality and high coefficient of heating surface of the rib. For the commonly used f38mm pipe, Welding fin height 28 mm, rib change coefficient can reach more than 5.5.
■ Antifraying. In ashes and ribbed pounding, component consume gradually, heating surface will not produce wear
■ No dust. The economizer can use higher air velocity to self-cleaning gray, Due to the parallel direction of rib and airflow, ashes will not subside on rib, the plugging of flue gas flow channel will not occur.