分布式热泵调峰型热电联产烟气余热回收系统评价

Analysis of the recovery system of flue gas from combined heat and power plant with distributed peak-shaving heat pumps

摘要:

为尽可能地提高燃气供热能力，分布式热泵调峰技术在热力站处二次网侧采用热泵进行供热调峰，同时利用热泵原理降低一次网回水温度，为热源处低温余热回收创造有利条件，进而提高系统供热效率.为了评价分布式热泵调峰技术在集中供热系统中的可行性和应用效果，以一套二拖一大型9F级燃气蒸汽联合循环背压供热机组为例，对分布式热泵调峰型燃气热电联产烟气余热回收供热系统和常规燃气锅炉调峰供热系统在设计工况及运行工况下进行比较.在系统输入燃气量不变的前提下，新系统较低的回水温度有利于回收更多的烟气余热，在提高系统供热能力、降低供热能耗方面具有优势.节能性和经济性分析表明，该系统供热能耗降低6%，动态增量投资回收期为3.1 a，可实现良好的节能、环保和经济效益.

Abstract:

To improve the natural gas heating supply capacity, distributed heat pump peak-shaving technology has great potential to be further studied and promoted. This technology is to use heat pump to adjust heat on the secondary network in substation, simultaneously, to reduce the return water temperature of primary network by using the principle of heat pump. Return water of primary network with low temperature creates favorable conditions to recover waste heat in heat source, and improve heating efficiency. This paper takes a set of two 9F gas-steam combined cycle back pressure heating unit as an example and evaluates its feasibility and application effect. It is compared with a general gas boiler peak-shaving system on the design and operation condition. For comparison, fuel consumption of these two heating systems are almost the same. Heating energy consumption of new system is reduced by 6%. Dynamic investment-increment payback period is 3.1 years, meaning that the new system has good economy. The research shows that the system can improve network transmission and distribution capacity, increase heating capacity and reduce heating energy consumption. And it also can ensure the safety of heating.