LT6891B - Geothermal power plant - Google Patents

Abstract

Invention in the field of energy, how to utilize the inferior heat of the earth's depths to generate hot water and electricity. The new geothermal power plant is suitable for working with low-temperature, widespread, and therefore much cheaper, simpler, relatively shallow and abundant geothermal energy sources. With the present invention, it is possible to use a part of the energy extracted from the same depths of the earth without external energy for the production of hot water from warm water.

Description

An invention in the field of energy for utilizing the inferior heat of the earth's depths to generate hot water and electricity. In western Lithuania, at a depth of about 1 km, there are warm saline water layers with a temperature of about 30-45 ° C. They were tried to be exploited. The Klaipėda demonstration geothermal power plant, which has been operating for more than ten years, was the only one of its kind in Lithuania, Latvia and Estonia. The following is a brief description of the geothermal power plant chosen as analogue and the difficulties encountered by the company. Using the above case as an analogue, it is appropriate to discuss how the existing geothermal power plant works and what the new differences and advantages of the proposed solution are.

“Klaipeda Geothermal Power Plant operates 4 wells. The pumps pump 38 ° C saline heat geothermal water from a Devonian layer at a depth of 1135 meters. Up to 700 m ³ of water can be obtained from two wells per hour, but only 450 m ³ of land is reclaimed. The heat of the geothermal water is removed by absorption heat pumps (4x12 MW) using a 54% aqueous solution of lithium bromide (LiBr) as the heat-absorbing working agent. After deducting the heat, the salty geothermal water is returned to another well a couple of kilometers away with powerful pumps. During the combustion of the gas, the lithium bromide solution is heated to 175 ° C with water prepared in the power plant's water heating boilers (3x16 MW). ' for heating incoming district heating water up to 70 ° C. The capacity of the geothermal power plant is 10-35 MW. The flow rate of the geothermal loop is 160-210 m ³ / h. Klaipeda Geothermal Power Plant (www.lqeos.lt)

The main differences between the analogue and the new geothermal power plant:

Klaipeda geothermal power plant raises warm salt water (T = 30-35 ° C) from the first borehole and returns the cooled water (T = 10-15 ° C) to another remote well to heat the warm water (T = 30-35 ° C) up to T = 70 ° C additional heat from the combusted gas is used.

The new geothermal power plant operates on a different principle. The new ones in the proposed geothermal power plant are:

• Basic idea • Principles of operation • Technologies and methods used • Technical constructions • Areas of application • Significantly higher benefits and lower costs • Possibility to operate completely without external energy supply • Possibility to operate in automatic continuous mode around the clock, all year round without any human intervention .

• Possibility to create a network of small geothermal power substations, locally serving various buildings, agricultural and industrial objects with a small radius.

The basic idea is that all the energy needed for the operation of a geothermal power plant is obtained only from the depths of the earth, and consumers can get hot (T = 60-70 ° C), warm (T = 30-40 ° C) cold (T = -10-0 ° C) water and electricity generated by a geothermal power plant.

Principles of operation - not salty warm water is generated from the depths, but heat is transferred (T = 30-35 ° C) with the help of a heat carrier circulating in a closed circle (fresh water, alcohol, water and alcohol mixtures). Hot water supplied to the consumer (T = 60-70 ° C) is obtained by heating the hot water (T = 30-35 ° C) with the help of a heat machine, transferring heat from the warm tanks (T = 30-40 ° C) to the hot tanks (T = 60-70 ° C), i.e. no fuel is burned for additional heating. Electricity generated by submersible motors is supplied to consumers.

Technologies and methods used - heat pipes, heat machine, staged heat exchange, heat recovery probe, submersible motor, autonomous control unit. The geothermal power plant does not use heat pumps at all.

Technical constructions - the whole geothermal power plant is assembled from four main modules:

• deep well module with heat recovery probe;

• heat machine, which separates cold, warm and hot streams from the module • hot (T = 60-70 ° C), warm (T = 30-40 ° C) and cold (T = -10-0 ° C) water tanks, designed to provide users with a module;

• Automatic stand-alone remote control module.

Areas of application - buildings, livestock, poultry, fish farms, greenhouses, refrigerators, agricultural and industrial facilities within a radius of the required hot, warm and cold water and electricity.

The difference between benefits and costs is that the geothermal power plant itself, with its design and operation, could operate at a cost that is ten times lower with a constant positive return. By installing an interoperable network of these small geothermal power plants, it is possible to supply large areas of the country with various energies.

Stand-alone modules - a geothermal power plant can be the size of a small substation or a separate container. The autonomous geothermal power plant module can be assembled separately as a whole in a massive industrial way and delivered and quickly built on site. A mobile version of the mobile geothermal power plant is also possible. The cost of manufacturing, building and using such a stand-alone autonomous module is tens of times lower than the current ones.

State of the art

Newly tested technologies and constructions are used: modular heat accumulator LT5636; stepped heat collector LT5665; universal heat capacity LT5739; high volume heat capacity system LT5836; heat machine LT5917; compressor engine LT6660; water power plant LT6751; heat pipes; submersible engine LT6786; autonomous remote control unit. A newly developed heat collection probe that allows heat to be transferred to the surface without heat pump technology. Analogous low-temperature geothermal energy technologies are practically non-existent, as the existing inertia provision, that it is not expedient, does not allow us to see what enormous geothermal heat resources are. Refrigerant technology can increase the range of heat generated, eg: T = -15 ° C / T = +40 ° C, i.e. 50-60 ° C difference, transferring 20-30% more heat at once. The new technology used also allows the generation of higher supply water temperatures, e.g. T = 60-70 ° C, without the use of any additional fuel for heating, but only from the heat transferred from the existing subsoil.

About the new heat carrier

This is a very important element of the invention, which requires not only well-functioning and reliable continuous operation of the geothermal power plant, but also the whole. Basically, “all the work is done by a heat carrier. It is the main heat carrier of a completely new type, with properly selected properties. It is possible to define exactly what the "ideal heat carrier" must have:

• Simple, inexpensive, widespread, safe for humans and the environment, harmless to equipment, non-hazardous, non-explosive, non-flammable, non-perishable, stable, fast and easy to manufacture, accumulates well and in large quantities, stores and transmits heat. , T = -20 ° C - T = +100 ° C, high heat capacity, light, lower than normal density, easy to lift and pump back. The list of requirements is quite extensive. The closest material to the listed characteristics is clean fresh water, which is well known to us. Because it is desirable to work even in the range of negative temperatures, it is advisable to use mixtures of water and alcohol in various concentrations. E.g. "Vodka", i.e. The mixture of 40% water and alcohol does not freeze even at T = -40 ° C. Antifreeze, for example at T = -20 ° C, increases the amount of energy transferred by a third. The mixture of water and alcohol has a lower density than pure water, making it easier and faster to lift.

• A major technological innovation: a cooled heat transfer medium is initially pumped down into the heat recovery probe placed in the borehole, which gradually heats down as it drops into the outer tube, and at the lowest point of the borehole, the heat is quickly transferred by an internal, well-insulated pipe, transferring the heat taken upwards. This is different from conventional technology, where from the very beginning you are trying to raise heavy salty warm water. The new technology creates its own rules: a heat carrier with a temperature that can absorb as much heat as possible in the depth must enter the well by contrast. Therefore, this method is also suitable for wells with different thermal water layers and can work successfully even in shallower wells, i. the potential of such technology will be very wide.

The essence of the invention

Maximum heat uptake takes place in the hottest area of the existing well. In the drawing, this shows the local warm flow zone h. The idea of the invention is simple - it is expedient to take heat where it is abundant. Compared to the amount of heat available in this environment, the heat probe captures and transfers up very little local heat. The volume of the warm area significantly exceeds the heat dissipated, so it is practically possible to take and transfer heat in unlimited quantities and for a very long time. From an economic and technical point of view, this means that a recessed heat recovery probe can operate successfully for many years without interruption. Another effective principle of this technology is to take the heat by making the largest temperature difference by pumping it into a refrigerated heat carrier. The temperature of the latter can be regulated by varying its composition and using cooled streams. In addition, as it descends, the cooled heat carrier gradually heats up as it flows through the outer supply pipe as it flows deep into the distance H, i. the downstream heat carrier takes heat from other levels of the geothermal well. The next subtlety of the invention is that instead of heat pumps, the heat transfer to the inner tube isolated from the environment is carried out by the heat pipes. This process is much faster than the transfer of heat through the walls of a conventional pipe, because the heat is transferred by means of rapidly evaporating gas (i.e. 3000-3500 times faster than usual). Therefore, the heat exchange in the borehole can be very fast, i. the incoming cold heat carrier can flow at high speeds and at the same time transfer larger amounts of heat in a short time. When raised, the heat transfer medium transfers heat very quickly through a stepped heat exchanger, cools down and is returned to the depth of the well, i.e. heat exchange above the geothermal well is also very rapid. The principle is very simple - the heat of the depths must be transferred to other structures without any interference, in which case the heat exchange processes are transferred to the module of the heat machine. The main idea of the invention is that you can't store a lot of energy for a long time, it's expensive, complicated and pointless. Energy has to move constantly. The thermal machine module also operates in contrast mode. Cold, warm and hot flow heat accumulators are used to pass the respective cold, warm or hot streams, transferring cold or heat to the appropriate containers. In this way, the geothermal power plant has cold, warm, hot water reserves that can be used to transfer energy at any time. Energy is forcibly transferred from the colder to the warmer heat accumulator by means of compressor motors. This constantly supports the transfer of energy in the desired direction. Without cold reserves, a geothermal power plant would not be able to function as efficiently. The principle that energy cannot be stored much and for a long time, it must be constantly transferred somewhere, means that the further path of heat transfer must be foreseen and very clear. It is therefore appropriate for a geothermal power plant to serve heat and cold consumers as close as possible. It is not expedient to transfer high-temperature heat over long distances, in which case it is better for consumers to purchase thermal machines that would raise the temperature of the heat flows to the required level instead. Energy consumers can be created next to the geothermal power plant: greenhouses, livestock, poultry farms, dryers, refrigerators, warehouses, supermarkets, industrial, agricultural and other objects - entities, energy consumers. This is a prerequisite because you cannot store much of the newly generated energy for long. Energy must be constantly moving, circulating.

The fact that a submersible motor with an electric generator used in the module of a heat machine can be used to generate electricity and supply it to consumers. In this way, a geothermal power plant uses only deep energy to store and transmit hot (T = 60-70 ° C), warm (T = 3040 ° C) and cold (T = -10-0 ° C) flows and electricity to consumers. energy. Therefore, the efficiency of such a geothermal power plant is extremely high.

Using an autonomous automatic continuous control module with computers, sensors and transducers, programs that control both individual processes and all geothermal power plant changes, it is possible to have a self-contained power plant that can be fully controlled remotely. Continuous technical systems without the constant involvement of people allow the creation of a network of geothermal power plants in this way, even where there are no people, i.e. in difficult and unfavorable conditions.

Technical result

A new type of geothermal power plant with new technology has been developed, which can supply hot and cold water and electricity to consumers continuously and for a long time, using only energy obtained from the depths to operate independently, without the direct involvement of people.

The invention is illustrated in the drawings:

FIG. 1 Heat machines and heat recovery modules

1. Thermal machine

2. Refrigerated capacity

3. Refrigerated accumulator

4. Warm accumulator

5. Hot accumulator

6. Hot storage capacity

7. Compressor motor

8. Compressor motor

9. Submersible motor

10. Stepped heat exchanger

11. Warm capacity

12. Water pumps

13. Outgoing cold stream pumped to the heat recovery probe

14. A stream of warm water lifted from the depths

15. Warm water flow pumped into warm storage tanks

16. Warm water flow to consumers

17. Chilled water flow for heat exchange

18. A cooled heat stream that transfers heat from a refrigerated container

19. Hot water flow to hot water storage tanks

20. Hot water flow to consumers

21. Heat recovery probe

Fig.2 Heat recovery probe from a geothermal well

Heat recovery probe with geothermal well

Lower part of the heat probe immersed in the geothermal warm water flow layer h (enlarged scale)

13. Cold heat carrier flow into the heat recovery probe through the outer tube

14. Flow of warm heat transfer medium through the inner tube of the probe

21. Heat recovery probe

22. Geothermal well

23. Inflatable, elastic, higher pressure heat probe retainers

24. An internal tube that raises the heat flow of the heat transfer medium

25. An external heat probe tube downstream of which a cooled heat transfer medium flow

26. Lower part of the thermal probe submerged in h

27. Thermal insulation around the inner heat transfer pipe

28. Heat pipes

29. Warm flow of heat transfer medium into the inner discharge probe tube, transferring heat from the environment

30. Protective ceramic heat probe layer

Fi g.3 Geothermal power plant module system

6, 11,2,12 Module for hot, warm, cold water storage tanks with pumps and piping

22. Geothermal well with heat recovery probe 21

31. Soil with H layer

32. Warm geothermal water layer h

33. Geothermal power plant

34. Thermal machine module

35. Autonomous automatic remote control module

The given diagram shows from which modules it is possible to assemble a set of modules of different types into a common energy system with a certain purpose, power and field of application.

How it all works

Since most of the functional energy modules are described in other inventions, the main principles of operation of a geothermal power plant will be described in a few concise sentences.

FIG. 1 Principle of operation of a thermal machine:

The cooled flow of heat carrier or water from the refrigerated tank 2 is continuously pumped to the refrigerated accumulator 3 by means of pumps 12. to the hot accumulator 5, from which the continuously circulating hot water is transferred to the hot storage tank 6 by means of the pump 12. During all these continuously repetitive operations, the heat is transferred from the colder tank to the warmer, hotter tank. Such an operation not only absorbs the heat transferred from the depths, but also additionally raises the temperature of the accumulated hot water, i. we have obtained hotter water than is in the environment without burning anything and without using additional external energy (eg electricity). Compressor motors run on compressed air. The thermal machine does not produce new heat, but only transfers the heat flows and concentrates the thermal energy more. It is incomparably cheaper and faster than additional heating of warm water by burning fuel. There can be many, but not many, thermal machines in a geothermal power plant, and their quantity and power are selected according to the amount of energy they want to store.

How a stepped heat exchanger works 10.

The heat flow 14 raised from the depths is pumped by the pumps 12 through the step heat exchanger so that the warm water 14 flows through the heat pipes, flows out the cooled flow 13 and is further pumped into the heat collection probe 21 through the outer tube 25 and the cooled flow 17 flows in. flowing in the opposite direction flows with a warm flow 15 and is further pumped by water pumps 12 into the hot water storage tanks 11. Rapid heat exchange takes place: hot flow - cool, cooled heats up. In this way, heat can be quickly taken away and transferred in other directions. Cold flow - deep, warm for accumulation.

Fig.2 Construction of the heat lifting probe and its mode of operation

A heat recovery probe 21 is attached to the geothermal well 22 by means of inflatable retainers 23. an outer tube 25 through which the cooled flow 13 enters the depth; a tube of heat tubes in the lower portion of the probe 28 that transfers ambient heat to the interior; as the cold heat carrier flow 13 heats up and flows 29 into the inner probe lifting tube 24 and finally rises upwards into the heated flow 14. The lower part of the heat probe 26 has a ceramic protective layer 30 which mechanically protects the heat from the walls through the walls. for the layer 28 and the latter for the lower and lower heating stream 13. The lower part of the heat collection of the probe 26 is immersed in a deep layer of warm water with a depth h. The upper part of the heat collection probe is simpler: the outer pipe 25, the thermal insulation 27 and the inner pipe flowing the warm flow 24, its length in the well is H.

Fig.3 Geothermal electrical general module diagram

Above ground: geothermal power plant 33 with internal thermal machine module MOSM 34; a module for hot 6, hot 11, cold 2 water storage tanks and pipes with pumps 12 for transmitting hot, hot and cold water flows to consumers; an automatic autonomous remote control module 35 for controlling all processes in a geothermal power plant automatically and remotely without human intervention; geothermal well 22 and geothermal deep heat recovery probe 21 with a total depth H + h, and the lower part 26 of the thermal probe is placed in the warm water stream. 30 m and more).

Claims (5)

Geothermal power plant consisting of several geothermal wells with supply and discharge pipes, water pumps, heat pumps, hot and cold water tanks, hot steam boiler house, control system, producing deep warm saline water, characterized in that the whole geothermal power plant is collected as a whole of the four main modules: (a) one deep well module with a submersible heat recovery probe; (b) heat module, which separates cold (T = -10-0 ° C), warm (T = 30-40 ° C) and hot (T = 60-70 ° C) flows into the module; (c) water storage tanks for pipes, water pumps, hot (T = 60-70 ° C), warm (T = 30-40 ° C) and cold (T = -10-0 ° C), for supplying consumers to the module; (d) an automatic stand-alone remote control module, with computers, sensors, sensors, programs that control both individual processes and all geothermal power plant systems and modules, acts as a whole, transferring heat from the borehole hot water layer to the heat recovery probe the machine module and cold (T = -10–0 ° C), warm (T = 30–40 ° C), hot (T = 60–70 ° C), water storage tanks, from which it transports cold by pipes and pumps, warm and hot water flows to consumers. Geothermal power plant according to claim 1, characterized in that a heat collection probe with an internal warm (T = 30-40 ° C) pipe carrying the heat carrier upwards is lowered into the geothermal well, which is protected by thermal insulation and placed in an external cold (T = -10 –0 ° C), has a heat transfer tube downstream, with a lower heat probe, with heat tubes enclosing the outer cold heat transfer tube and a protective, ceramic-coated top layer that is drained into the geothermal well heat (T = 30–40 ° C). , a body of water. Geothermal power plant according to Claims 1 to 2, characterized in that the heat collection probe is mounted and maintained in the geothermal well by means of flexible inflatable retainers. Geothermal power plant according to Claims 1 to 3, characterized in that the heat carrier flow in the cooling machine module is continuously pumped from the refrigerated tank by means of pipes to a cooled storage tank. the heat gradient to the heated (T = 30-40 ° C) accumulator, and from the latter before the heat gradient is transferred by piping to the hot (T = 60-70 ° C) by means of a compressor motor, from which the continuously circulating hot water is transferred by means of a pump to a hot storage tank (T = 60-70 ° C), and during all this repetitive operation the heat is transferred from the colder tank to the warmer, hotter tanks, which not only absorbs the heat transferred from the depths but also raises the accumulated heat. water temperature. Geothermal power plant according to claims 1 to 4, characterized in that the heat flow (T = 30–40 ° C) raised from the depth in the module of the thermal machine is pumped from above through a staged heat exchanger so that warm water flows down through the stages. tubes flowing in a cooled flow (T = -10–0 ° C) and further pumped to an in-depth heat recovery probe through an external pipe, and the flow flowing from the bottom into the stepped heat exchanger (T = -10–0 ° C) flowing in the opposite direction flows in a warm flow (T = 30–40 ° C) and is further pumped by water pumps into the warm water (T = 30–40 ° C) storage tanks, during which rapid heat exchange takes place: hot flow - cool, cooled heats up.