DE2605527A1 - Thermal power station using fossil fuel - has steam turbine and storage tank in hot water circuit parallel to heat consumer - Google Patents

Abstract

Power station with back-pressure steam turbine for limited to average power outputs has a hot storage tank positioned in the hot water circuit parallel to the heat consumer. An air cooler is located in the same circuit parallel to the consumer and the store. The cooling capacity of the cooler is designed to be from one fifth to one sixth of the thermal power of the turbine. The cooler is associated with a blower or a water spray or both. A feed water tank is connected to a load cycle with a heat exchanger which simultaneously serves for preheating the exhaust steam condensate.

Description

.Heating power plant

The invention relates to thermal power stations for the generation of electrical Energy and heating, in particular heating power stations based on fossil fuels with back pressure turbine for small to medium power.

Combined heat and power plants are operated with a counter-pressure turbine or with an extraction condensation turbine equipped. In the case of a connected back pressure turbine, an auxiliary condensation is used and in the case of the extraction condensing turbine, the condensing part of the fuse the electrical power, the specific investment costs of the thermal power stations average output are not below those of large condensing power plants, who also work on the basis of fossil fuels. A performance price text for one fed into the electrical supply network by the thermal power stations Performance - reduced by the parallel journey - and the reserve fee - not to cover the fixed costs for generating the electrical power. To this one Compensating for or overcompensating for the disadvantage becomes the advantage of lower fuel costs perceived due to the use of the condensation heat as thermal heat in the way, that the cogeneration plant has the highest possible number of hours of use, i.e. during the Heating season is operated continuously.

The power generation of such a thermal power station is directly dependent from the heat emission. It follows from this that full performance in summer is only possible through condensation or auxiliary condensation can be achieved.

The load fluctuations resulting from fluctuations in heat demand conversely assume a reduced demand for electrical power and lead thus to: loss of efficiency.

The generation of electricity in the off-peak times (night) forces withdrawal the performance of economic working units (nuclear power plants, lignite-fired power plants).

The invention is based on the object, electrical power and Heating by a counter-pressure thermal power station connected largely independently of each other To make the work available to consumers only in times of high electrical power Use the load and at the same time ensure a secure peak load in summer.

The fossil fuel-based thermal power station with a back pressure turbine for smaller to medium performance, which solves the above-mentioned task, is marked through a storage tank, which is in the heating water circuit parallel to the heat consumers is switched.

The solution according to the invention allows a thermal power station with a Back pressure turbine discontinuous only during the high load hours of consumption to operate on electrical energy.

At the same time, this cogeneration plant will also make extensive adjustments in the electrical load curve, for example in the midday hours. The storage tank switched into the heating water circuit of the heat consumer takes Excess heat generated during the operating times of the thermal power station in order to supply the connected heat consumers during downtimes to hand over to them.

In the further development of the main inventive concept is in the heating water circuit the heat consumer parallel to this and the connected storage tank an air cooler switched on.

During the summer months, i.e. in times of the slightest decrease on the part the heat consumer, primarily heat consumption for domestic hot water preparation, the air cooler allows the operating times for full load of the cogeneration plant to expand an economical number of operating hours for electricity generation.

The design of the exchange performance of the air cooler is expedient to 1/5 to 1/6 of the thermal output of the back pressure turbine.

The air flow through the cooler can be done with natural draft, There is the possibility of forced ventilation to increase or change performance and / or sprinkling water on the cooling surfaces.

Using a feed water tank enlarged to form a storage tank the way is opened for this, through the full load of electrical energy generation in addition to providing peak load. This peak load is also within only a few seconds without noticeable thermal stress on the machine to increase.

The proposed solution will provide at least one during the heating season 6-hour and thus economical full load operation of the heating power plant and at the same time a guarantee of performance guaranteed. The operation of the thermal power station, discontinuous during peak periods of electrical energy demand, i.e. during the day alone, leads to a design of the thermal power station that is twice as large as that of the design on continuous operation. That means at the same time that already with proportionate small heat output thermal power stations operated economically and low specific Investment costs can be achieved.

The solution found leads to a simple, clear structure, a decrease in the specific cost of generating electrical energy and the possibility of electrical load peaks beyond full load in the order of magnitude of around 12% of the installed power plant capacity.

The proposed thermal power station is for peak and medium load operation equally suitable, independent in the choice of location, and the generation of electrical Energy takes place almost independently of the provision of heating.

To explain the inventive solution is in the drawing Cogeneration plant with downstream bleed back pressure turbine shown schematically.

The steam generated in the boiler (1) on the basis of fossil fuels is via the line (2) of the bleed back pressure turbine (5) to generate electrical Energy supplied in the coupled generator (4). The bleed back pressure turbine has Over three tapping stages of a high (5a), a medium (5b) and a low pressure stage (5c). The turbine exhaust steam after the last stage (3d) is via the line (5) fed to the turbine exhaust steam condenser (6) and condensed in this. The heat is connected to a heating water circuit - flow line (10) and return line (11) - transferred. Heat consumers (12) are switched on in this water cycle. A circulation pump (15) carries the cooling water - heating water for the heat consumers - Via the condensation surfaces of the heating condenser (6), flow line (10), heat consumer (12) and return line (11) back into the condenser. In parallel with the heat consumers there is a storage tank (14) with charging pump (15) and shut-off valve in the heating water circuit (16) switched on, so that if there is no waste heat generation - the thermal power station is out of operation - to take over the supply of the heat consumers. In this case the shut-off valve is (17) opened in the bypass (18) to the charge pump (15) and the shut-off valve (16) closed.

In the event of peak loads in electrical energy generation and Sufficiently charged storage tank or insufficient heat consumption by the consumer An air cooler (19) with a shut-off valve (20) can be switched on as an additional cooling surface will.

This air cooler has a fan to adjust the output (19a) and a trickle device (19b). A line opens into the exhaust steam condenser (21) for make-up water. The pressure maintenance of the heating water circuit is not shown.

The exhaust steam condensate reaches the via line (30), pump (31) Three-way valve (52). During normal operation, the exhaust steam condensate is over Lines (33,34,35) with interposed heat exchangers (56,5) and via the Cascade (38a) supplied to the supply of the feed water tank (38). Via line (40) with feed pump (41) the feed water is fed into the boiler. The heat exchangers (36,37) are connected via lines (50,51) and the cascade (38a) via line (52) Anzay steam from the stages (5c, 3b, 5a) is supplied. The accumulating in the heat exchanger (37) Condensate first enters the via line (60) with condensate drain regulator (61) Heat exchanger (36) and is together with its condensate via the line (62) with the condensate drain regulator (63) fed to the turbine condenser (6). To leave of peaks in electrical energy requirements going beyond full load the three-way valve (32) on the line (70) and the feed water tank connected to this (38) switched. The feed water is used while avoiding the extraction of bleed steam taken from the feed water tank (38) by feed pump (41) via line (40).

For charging the feed water tank, which also serves as a storage tank (38) is also used by a line (80) connecting the lines (33 and 70) to one another Charge pump (81) and shut-off valve (82). During full load operation, you can use the charge pump with the shut-off element (82) open, a partial flow from the feed tank (38) withdrawn and over the heat exchanger (36,37) and the cascade (38a) with bleed steam heated and returned to the feed water tank (38).

Claims (5)

Claims Combined heat and power plant based on fossil fuels with a back pressure turbine for small to medium performance, g e k e n n n -marked by a memory (14), which in the heating water circuit (10,11,13) parallel to the heat consumers (12) is switched. 2. Cogeneration plant according to claim 1, g e k e n n z e i c h -n e t through one in the heating water circuit (10,11,13) parallel to the heat consumers (12) and the air cooler (19) switched on in the memory (14). 3. Cogeneration plant according to claim 2, g e k e n n z e i c h n e t through an air cooler (19), the cooling capacity of which is reduced to one part, in particular to 1/5 up to 1/6 of the thermal output of the back pressure turbine (3) is designed. 4. Cogeneration plant according to claim 2 or), g e k e n n z e i c hn e t by an air cooler (19) with a fan (19a) and / or a water sprinkler (19b). 5. Cogeneration plant according to claim 1 and the following, g e k e n n -z e i c h n e t by a feed water tank designed in a manner known per se as a reservoir (38) and a charging circuit (80,) 3,34,35) with switched on, by bleed steam (50,51) acted upon heat exchangers (36,37), which also preheat the exhaust steam condensate to serve.