The solution of thermal power station
As the connection station between heatsupply network and users in the urban central heating system, the thermalstation can have different connection methods according to different conditionsof heat supply network and users to adjust and convert the heating media fromheat supply network in order to satisfy the user’s requirements and haveconcentrated measurement and detection of heating media quantities andparameters.
Civil thermal station for hot water: theheating equipment can be directly or indirectly connected.
①For directly connected equipment, the heating media from heat supply networkcan be directly sent to user’s system. When water temperature calculated byheat supply network is higher than that calculated by user’s heating system,the mixing device shall be established to partially mix the heating returnwater into supply water in order to reduce the supply water temperature user’ssystem. Water jet ejector or mixing pump can be used as mixing device.
②For indirectly connected equipment, the user’s system is separated from thepressure of heat supply network; the heating media from heat supply network hasno direct connection with user’s system but delivers heat through surface heatexchanger. Fast pipe heat exchanger and plate heat exchanger are widely usedcurrently. The water cycle which is sent to user’s system is driven by waterpump.
There are open type and closed type hotwater supply systems in civil hot water thermal station. In closed type hotwater supply system, the feed water (running water) is heated by the water fromheat supply network through surface heat exchanger and then sent to use’ssystem driven by itself. The fast pipe, plate and displacement heat exchangersare widely used. In case the conveying distance for hot water supply is long,the circulating pipe and circulating water pump shall be provided to avoid thetemperature reduction of circulating water when it is stopped. The user’s hotwater supply and heating system can be connected with heat supply networkthrough parallel or series connection. In open type hot water supply system,the water is directly taken from heat supply network and will be used aftermixing of supply and return water and the temperature adjustment.
The heating media are directly sent toheating equipment in air conditioning system through ventilation heating systemof thermal station.
In case that the flow required by user cannotbe guaranteed by pressure difference of heat supply network, the water pressingpump shall be established in thermal station and related measures shall betaken to control the water flow in heat supply network. The dirt separatorshall be installed in thermal station to ensure normal operation of heat supplynetwork by preventing impurities in heat supply network from entering thermalstation equipment and preventing impurities in user’s system from entering heatsupply network. In case the feed water has higher hardness, the simple watersoftening equipment shall be installed in thermal station to soften water andavoid scaling in heat exchanger and pipeline. The processed water can also beused as make-up water for heating system.
The industrial steam thermal stationshall provide production process, heating, air conditioning, cooling and hotwater to factories. The steam from heat supply network will be sent to steammanifold firstly, adjusted by reducing valve (or desuperheater) according toworking pressure and temperature required by steam equipment and then deliveredout separately. In hot water heating system, the secondary water is heated bysteam-water heat exchanger and then delivered by circulating water pump; or thesteam ejector will be used to promote circulation by using steam pressure toheat the water.
As an important component in industrialsteam thermal station, the condensed water recovery equipment is mainlycomposed of equipment including condensate tank, condensate pump and secondaryevaporation tank and accessories including steam trap and water seal. The openand closed type condensate tanks are used for collecting condensed water fromsteam systems. In open type water tank, the pipeline corrosion may occur sincethe oxygen in the air is soluble in water when condensed water meets the air. Theinstallation of water seal makes the water tank closed and separated from air.If the condensed water carries steam, the secondary evaporation tank shall beestablished to separate and utilize the steam in order to reduce thermal energylosses and avoid steam-water impacts by preventing the steam from enteringcondensate pipe in heat supply network. The condensed water in water tank issent to heat supply network through condensate pump. The functioning of steamtrap, an accessory for automatic discharge of condensed water, is veryimportant to the normal operation for condensed water recovery system.
The scale of thermal station can berandomly adjusted according to quantity of user connected and complexity; theheating may have one building (also called thermal point) or one buildinggroup; it can be built independently or be built in the building.