Based on absorption heat cogeneration district heating system
2017-07-20

 

In recent years, with the increase of the urban heating area and increase of industrial workshop, production line construction, a rapid growth of the heat consumption in China. Analysis from the way of heating, heating of the residents in our country mainly adopts central heating, small and medium-sized regional boiler rooms cogeneration way, domestic coal-fired furnace, etc. Thermoelectric coupling factory way is to use the fuel of high grade heat power generation, the low grade heat energy heating technology of comprehensive utilization of energy. The method has high efficiency, covers an area of less, saving water, etc. Conventional cogeneration system still has some problems, however, due to the large thermal power plant heating load center distance far away, and the larger heating and heat supply network transmission capacity become bottlenecks, thermal pipe network investment is increased, a secondary network in thermal station in heat transfer temperature difference is bigger, cause a lot of the irreversible heat loss, and the steam turbine exhaust steam directly into the cooling tower for large latent heat of vaporization has not been fully utilized.
In view of the above problems, the company designed a cogeneration district heating system based on absorption heat transfer. This system can improve the heat utilization efficiency, reduce network investment, and has good stability.
Of the technical scheme of the invention is:
Inside the condenser in power plant, the steam absorption heat pump and soda heat exchanger, water - water heat exchanger in combination way of recycling plant waste heat heating hot water and heating network, at the end of the use of hot water operated significantly reduce absorption heat pump and water - water heat exchanger network return water temperature. A network for a dramatic rise in the return water temperature difference, therefore, significantly increased the heat supply network transmission capacity, reduce the investment of the entire network. In order to guarantee the system stability before getting into hot water operated absorption heat pump heater, join a separate control network by using automatic control technology to detect a network outlet temperature of the water supply, heating function.
In thermal power plant, a part of the steam turbine, steam driven generators, another part of the high temperature steam were input to the absorption heat pump, heat exchanger and soda in steam absorption heat pump as a heat source at the top to participate in the heat. Steam turbine exhaust into the condenser, the heat transfer part of hot water into the water - water heat exchanger in a backwater heating, another part as a low temperature heat source into the absorption heat pump, heat exchanger after returning to the condenser. A backwater successively into the water - water heat exchanger, absorption heat pump, the steam - water heat exchanger, in turn, as a network after heating water enter into the heat supply network. The heat-supply heater testing into the water temperature in heat supply network, automatic adjustment.
In heat exchange station, a network as a drive into the hot water operated absorption heat sources, water after heating and cooling water - water heat exchanger heating secondary side heating, hot water cooled into hot water operated absorption heat pump as a heat source, low end exothermic temperature returns to the return water temperature of thermal power plant. Secondary side water into the hot water operated separately complete absorption heat pump and water - water heat exchanger heat transfer.
Beneficial effects of the present invention is:
1, in the thermal power plant, through the water - water heat exchanger using the low grade heat source in the condenser increased a net return water temperature, reference absorption heat pump at the same time, the use of steam turbine steam drive recovery of low grade heat absorption heat pump, increase the energy utilization.
2, the absorption heat pump widening for the return water temperature difference, greatly improve the heating capacity of heat supply network, reduce the pipe diameter, reduce network investment. And through different heat exchange device, can get different temperature of the secondary side of hot water supply temperature.
3, create conditions to improve the efficiency of thermal power plant. The very low return water temperature, can be more easy to recovery of waste heat power plant condenser, so as to lay a foundation for improving the system energy efficiency.
Heater
4, through the network to ensure the stability of the system.