RU84919U1 - HEAT AND POWER INSTALLATION - Google Patents

Abstract

 A biogas thermal power plant, a product of sewage sludge treatment, designed for the simultaneous generation of heat and electric energy and containing a block of digesters and gas pipelines, a gas tank unit, a biogas cleaning and compression unit, a piston engine block with electric generators, a heat exchanger block, a duct and smoke unit pipes, a compressor for supplying purified biogas, a pressure regulator for supplying purified biogas to the block of gas-piston engines with electric generators, a pump for water cooling to the piston engine block with electric generators, a circuit for supplying recycled water to the power generating units, characterized in that the heat power plant is equipped with a deaeration and chemical water treatment unit connected via a pipeline to the steam generator and a steam comb mounted behind it with a distributor for supplying water vapor to the corresponding nozzles of the digesters block, as well as a pipeline with a shut-off valve for supplying a heated sediment from the system sewage through a block of heat exchangers into a block of digesters.

Description

The utility model relates to the field of thermal energy and is intended for the simultaneous generation of thermal and electric energy. At the same time, renewable energy of biogas, a product of sewage sludge treatment, is used as fuel in generating plants. The heat and power plant is integrated into the existing standard scheme of heat and power supply of wastewater treatment plants, while at the same time improving the reliability of power supply to wastewater treatment plants. At the same time, the generated electric energy can replace the corresponding amount of energy required for the operation of treatment plants and reduces the load on the energy system, for example, of a municipality.

Known is a combined system for the simultaneous production of heat and electric energy based on a hot water boiler plant (RF patent No. 2261335, F01K 7/12, publ. 2005.09.27), consisting of a hot water boiler, a heat supply system for consumers with a network pump and make-up water line, this combined system is equipped with a Stirling engine with an electric generator on the main shaft, an intermediate heating circuit, consisting of a compressor and a heat exchanger located on the chimney of the boiler plant, while first circuit passes through a Stirling engine heater, a line-up water passes through a cooler of the Stirling engine.

The disadvantage of this invention is that to generate heat and electric energy, a plant is used that works only on the basis of the Stirling engine used in boiler houses of mini-TPPs, which does not allow the invention to be used with engines operating on other principles.

Also known is a heat power installation for utilizing the heat of exhaust gases of a gas turbine engine (see RF patent No. 2266414, IPC F02C 6/18, F01K 23/10, publ. 2005.12.20), comprising a heat producing system, an energy producing system, and an automated control and regulation system for operation . This invention is the closest analogue to the claimed utility model and is taken as a prototype.

The disadvantage of this system is that it focuses only on the utilization of the heat of exhaust gases of gas turbine engines and does not provide for the utilization of a renewable energy source, for example, biogas.

The purpose of the utility model is to create a thermal power plant operating on biogas with a low calorific value and a high content of carbon dioxide, hydrogen sulfide and humidity.

The purpose of the utility model is achieved in that the thermal energy obtained by utilizing the heat of the exhaust gases and cooling the internal combustion engines of gas reciprocating plants is used to heat the sewage sludge, as a result of this process biogas is produced, which is used as fuel for the heat power plant.

The closed loop system of the heat and power plant is fully automated, coordinated with the operation of external electrical networks and the existing boiler room.

Thermal power plant consists of the following main blocks (see the block diagram in figure 1):

1. Block digesters and gas pipelines.

2. The block of gas holders.

3. Block cleaning and compression of biogas.

4. The block of gas piston engines with electric generators.

5. Block heat exchangers.

6. Block of steam generators.

7. Deaeration and chemical water treatment unit.

8. The block of flues and chimneys.

9. Steam comb.

10. Electrical switchgear.

11. A pipeline with a shut-off valve for supplying biogas from block 2 to block 3.

12. Compressor for supplying purified biogas.

13. The pressure regulator for the supply of purified biogas to block 4.

14. A pipeline with a shutoff valve for draining water from block 5 to block 1.

15. Pump for supplying water cooling to block 4.

16. Pipeline with shut-off valve and check valve.

17. A pipeline with a shut-off valve for draining water from block 4 to block 5.

18. A pipeline with a shut-off valve for supplying heated sewage sludge from the treatment plant to block 1.

19. The pipeline with a shutoff valve for supplying the generated steam from the comb 9 to the digesters 1.

20. The pipeline with a shut-off valve for supplying generated steam to the gas distribution comb 9.

21. The pipeline for the removal of flue gases from block 4 to block 6.

22. The shutoff valve of specially prepared water that previously passed through the deaeration and chemical treatment unit 7.

23. The shutoff valve of the water supplied to the block 7.

24. The line for supplying circulating water to block 4.

25. The return water return pipe from block 4.

As experience in the industrial use of a power plant shows, in the process of wastewater treatment at treatment plants, about 18 thousand cubic meters are formed. m / day of liquid sludge (about 6.5 million cubic meters / year). All the precipitate formed is fermented in digesters 1 at a temperature of about 53 ° C, resulting in the production of biogas containing about 65% methane.

Unlike traditional gas piston plants using natural gas of high calorific value (~ 8100 kcal / nm3), gas piston engines of the proposed installation operate on biogas with low calorific value (~ 5100 kcal / nm3) and a high content of carbon dioxide and humidity.

The biogas formed in the digesters 1, through the gas network of the WWTP enters the gas tanks 2, and then to the installation of its purification and compression 3 (compressor 12, pressure regulator 13). The first stage of biogas purification involves the removal of hydrogen sulfide. The second stage involves the removal of non-hydrocarbon organic compounds, including silicon (siloxanes), which is produced during the adsorption process in a column loaded with activated carbon (not shown conventionally in FIG. 1).

Purified biogas through control automatics 13 enters block 4 to the gas piston engines, where it is disposed of.

Block 4 operates in the mode of cogeneration of gas piston engines by electric generators with the simultaneous production of heat and electric energy. As experience shows, the total electric power of electric generators is ~ 10 MW. The generated electricity through the medium voltage network and switchgear 10 is sent to transformer substations and further to consumers.

The thermal energy generated in block 4 consists of two streams:

1. The heat of the exhaust flue gases.

2. Heat from the cooling of gas piston engines.

Exhaust flue gases 21, having a temperature of 450-470 ° C, are supplied to steam generators 6. In them, the heat of the flue gases is converted into steam energy, then the exhaust gases are removed by the chimneys 8. To produce steam, specially prepared water 22 is supplied, previously passed through the deaeration units and chemical preparation 7. The generated steam 20 through the distribution comb 9 is fed to the injectors of the digesters 1. This method of utilizing the thermal energy of the exhaust gases is chosen in order to preserve the existing systems on the WWTP in heating digesters with hot steam.

In the course of work, water cooling of the gas-piston engines of unit 4 is carried out using pump 15 through circulating water through lines 24 and 25. After the heat energy is taken from the units, heated water is supplied to the external channel of the pipe-in-pipe heat exchanger 5, where heated sediment is fed into the internal pipe 18, fed into digesters (optionally either primary sediment or excess sludge from both treatment plant blocks can be passed).

The proposed heat power plant provides with electricity about 50% of its main technological consumers and about 30% of the plant’s heat demand. The connection scheme makes it possible to successfully integrate the energy flows of the proposed heat power installation into the existing energy balance of the consumer, providing increased reliability of energy supply and the most efficient use of biogas.

The proposed heat power installation is an effective solution for biogas utilization using the cogeneration of heat and electric energy.

The purpose of the proposed utility model is achieved by the fact that the thermal energy obtained by utilizing the heat of exhaust gases and cooling gas piston engines is used to heat the sewage sludge, as a result of this process biogas is produced, which is used as fuel for the heat power plant.

The proposed heat and power plant provides a significant increase in the reliability of the power supply of treatment facilities, reduces the load on the urban energy system, which allows you to reorient the appropriate capacity to solve urban problems.

The use of a renewable energy source - biogas helps to increase the energy and environmental performance of wastewater treatment plants.

In addition, the transfer of digesters to hot water (partially) will reduce the supply of sharp steam to digesters, which will positively affect the methane digestion process.

Placing a heat and power plant in close proximity to electrical consumers of treatment facilities eliminates the need for the construction of extended electric and heat networks, which provides significant economic benefits.

Claims (1)

A biogas thermal power plant, a product of sewage sludge treatment, designed for the simultaneous generation of heat and electric energy and containing a block of digesters and gas pipelines, a gas tank unit, a biogas cleaning and compression unit, a piston engine block with electric generators, a heat exchanger block, a duct and smoke unit pipes, a compressor for supplying purified biogas, a pressure regulator for supplying purified biogas to a block of gas-piston engines with electric generators, a pump for water cooling to the piston engine block with electric generators, a circuit for supplying recycled water to the power generating units, characterized in that the heat power plant is equipped with a deaeration and chemical water treatment unit connected via a pipeline to the steam generator and a steam comb mounted behind it with a distributor for supplying water vapor to the corresponding nozzles of the digesters unit, as well as a pipeline with a shut-off valve for supplying a heated sediment from the system sewage through a block of heat exchangers into a block of digesters.