RU149415U1 - THERMAL POWER PLANT - Google Patents

Abstract

This utility model makes it possible to efficiently use the heat resources available at the power plant: solar heat and the heat of turbine condensers. This is achieved by the hot water heating system after cooling the turbine condensers in the solar water heater and the additional use of hot water in the air cooling apparatus (ABO), the heated air from which enters the boiler’s air heating system. Sequential installation of an additional solar water heater and ABO on the hot water line from the condenser makes it possible to increase the energy efficiency of the air heating system with fluctuations in the temperature of the ambient air and the cooling water of the condensers. The feasibility of installing hot water batteries and their size should be checked in a specific design. It is also advisable to use solar water heaters with a plastic sun-sensing surface (such devices with a surface of 2.5 m ² are used when heating water in Ulan-Ude)

Description

The subject of the proposed utility model is a thermal power plant operating on fossil fuels (gas, fuel oil, coal, middle distillates).

Known thermal power plant, which includes a boiler plant for the production of steam through the use of heat of combustion of fossil fuels. (L. Sterman. Thermal and nuclear power plants, 1982)

Water vapor from the boiler plant is sent to a steam turbine, after which there is a water-cooled condenser.

The boiler plant is equipped with an air supply system necessary for combustion.

The disadvantage of the described thermal power plant is that the air from the atmosphere is supplied to the boiler system at ambient temperature, and the heat of the hot water after the condenser is removed to the environment. Another disadvantage of this system is its low cost-effectiveness for countries with high ambient air temperatures (especially for thermal power plants whose turbine condensers are cooled by sea water - Australia, Israel, Africa, Southern Europe, etc.)

At the same time, the problem of efficient use of solar energy is very relevant for these countries, and this problem is also relevant for Russia in such areas as Buryatia, Krasnodar, Altai, etc.

The proposed utility model solves the problem of eliminating these drawbacks by using solar energy and heat from heated water after the condenser to heat the air at a thermal power plant.

A thermal power plant (see drawing) consists of a boiler plant 1, a steam turbine 2 with an electric generator 3, a condenser 4, a pump 5, a heating system 6, a hot water pipeline 7, a solar water heater 8, an air cooling apparatus 9, an atmospheric air intake pipe 10, flue gas heater 11. It is possible to install additionally, after the solar heater, a thermally insulated tank - battery.

In this case, the solar water heater 8 and the air cooling apparatus 9 are additionally included in the scheme of the thermal power plant.

The system operates as follows (see drawing).

The scheme is maximally simplified (elements not related to this proposal are not shown).

In the boiler installation 1 due to the combustion of fuel, water vapor is produced, which enters the steam turbine 2, sitting on the same shaft with the electric generator 3.

The exhaust steam is condensed in a condenser 4 cooled by industrial or sea water.

Condensate of water vapor by pump 5 through heating system 6 (including deaerators and feed pump) is supplied to boiler plant 1. Heated water from condenser 4 (partially) is supplied via pipeline 7 to solar water heater 8. Then, additionally heated water from the output of solar heater 8 is supplied to the inlet fitting of the coolant inlet of the air-cooling apparatus 9 and then discharged into the process water line or at sea.

Combustion air is taken from the atmosphere through a pipe 10, heated in an air cooling apparatus 9, and after it enters the air supply system of a boiler plant 1 in front of the flue gas heater 11.

The air supply is carried out by a fan (the latter, as a rule, is combined with the fan of the air-cooling device 9).

The proposed installation in a simple way is used in addition to the heat of the fuel as the heat of the condenser of a steam turbine and solar heat.

Example:

Power plant with a capacity of 1000 mW (1 million kW) powered by fossil fuels and whose condensers are cooled by sea water (Mediterranean Sea).

The average night temperature in January-May, October-December (8 months) is 12 ° С, and the average daily temperature is 23 ° С.

In June-September (4 months), the average night temperature is 23 ° C, daytime 30 ° C. The power of solar radiation for 4 summer months is 7 kW. h / m ² . day, for 8 winter months 4 kW. h / m ² day.

The average temperature of the heated water after the turbine condenser in the summer months is 39 ° C (i.e., the sea water temperature is 28/30 ° C) in the wintertime is 31 ° C (water temperature 18/25 ° C). The average temperature of heated water after solar heating in the summer months is 61 ° C, in the winter 51 ° C.

Fuel consumption is:

- At night - 0.27 · 1,000,000 · 0,8 = 216 t / h,

- In the daytime - 0.27 · 1,000,000 = 270 t / h.

Amount of air supplied to the air cooler:

- At night 15 · 216 = 3240 t / h,

- In the afternoon 15 · 216 = 3240 t / h.

Air heating (the calculation does not take into account the possibility of accumulation of heated water in front of ABO in the summer of 51 ° C, in winter 41 ° C (in the daytime, i.e. when the solar water heater is working)).

At night, air heating is 25 ° C in winter and 33 ° C in summer (i.e. only the heat from the turbine condenser is used).

It can be seen from the example that in summer, the condenser heat is almost not used (taking into account the required temperature difference ABO), but the heat of the solar water heater is used effectively.

At night, especially in the winter months (on days when the solar water heater does not work), it is possible to more efficiently use the heat of heated water after the condenser by changing the temperature difference in ABO by increasing the flow of hot water (the heat of which is several times greater than the heat transferred to the air in ABO )

Air heating at night:

- in the summer at 10 ° C (from 23 ° C to 33 ° C)

- In winter at 14 ° C (from 12 ° C to 26 ° C)

Amount of heat transferred to air in ABO:

- In the daytime:

- In the summer of 230 · 4050 · 21 = 1956100 kcal / h (27746 kW)

- In winter 230 · 4050 · 18 = 16767000 kcal / h (19496 kW)

At night time:

- In the summer of 230 · 3240 · 10 = 7452000 kcal / h (8665 kW)

- In winter, 230 · 3240 · 14 = 10432900 kcal / h (12130 kW)

Moreover, the hours of operation of the solar water heater 8 hours / day.

Then the total heat saving is:

- In the summer of 8 · 120 · 22746 + 16 · 120 · 8665 = 38 million kW * h

- In winter, 8 · 240 · 19496 + 16 · 240 · 12130 = 84 million kWh

In total for the year ≈122 million kWh, which is equivalent to 12,200 tons / year of fuel.

At a fuel price of $ 700 / t. Savings of ≈7840 thousand $ / year.

Payback period less than 1 year.

Claims (1)

Thermal power plant, which includes a boiler plant for the production of water vapor with an air supply system for burning fuel and a steam turbine with an exhaust steam condenser, characterized in that the air supply system is additionally equipped with a solar water heater and an air cooling apparatus, while the hot water outlet pipe after the condenser is connected to the inlet of water to the solar water heater, the output of hot water from the solar water heater is connected to the inlet of the coolant to the apparatus air cooling, and the outlet of the heated air from the air cooling apparatus is connected to the inlet to the air supply system in front of the flue gas air heater.

Images