WO2011138471A1

WO2011138471A1 - Use of heat pumps for heating with heat dissipated in thermal power plants

Info

Publication number: WO2011138471A1
Application number: PCT/ES2010/070306
Authority: WO
Inventors: Antonio Diaz Gonzalez
Original assignee: Antonio Diaz Gonzalez
Priority date: 2010-05-06
Filing date: 2010-05-06
Publication date: 2011-11-10

Abstract

The invention relates to the use of any technical design encompassed within the heat pump concept, intended to recover heat that is released from thermal power plants so that it can be used for heating, thereby preventing or reducing the discharge thereof. The heat pump concept is a technical concept having various different technological embodiments and, as such, the invention includes all existing embodiments in a generic manner, since they cannot all be cited individually and since there is a possibility that new embodiments could be developed relatively easily. The invention is suitable for systems used to heat premises, including both public and private spaces and domestic and professional spaces. The invention is also suitable for premises used for lairaging animals and premises used for growing and conserving plant species and the products thereof, which premises use heating systems.

Description

USE OF HEAT PUMPS FOR USE FOR HEATING HEAT DISSIPPED IN THERMOELECTRIC POWER STATIONS

SECTOR OF THE TECHNIQUE

The present invention is included within the premises heating systems, and can be extended to both public and private, and within these, both domestic and professional. Also included are premises dedicated to animal housing that use heating systems, and even the breeding and conservation of plant species and their products that use means to be heated.

STATE OF THE TECHNIQUE

RESIDUAL HEAT IN THERMOELECTRIC GENERATION

It is known that the process of generating electricity from fuels has very low yields, understanding as such performance the relationship between the total caloric content of the fuels, and the electrical energy finally obtained.

We refer here to all thermoelectric generation processes, that is, to all cases of electric power generation from hot fluids, regardless of whether hot fluids are obtained from different types of fuels, provided that the result of This combustion be hot fluids. Therefore, thermonuclear generation processes are included as long as they are It generates electrical energy from hot fluids, although these fluids do not heat up as a result of combustion in their most common sense. In this case, heat is obtained from nuclear reactions. However, despite the fact that combustion does not occur in the traditional sense, it is common to refer to the materials used as nuclear fuel, giving this combustion designation extended to the processes that occur in nuclear reactors.

Among these thermoelectric generation processes we can mention: coal-fired power plants, which generate steam at high temperature for use in turbines; gas plants, which pass the product of gas burning through turbines, or burn it in internal combustion engines; combined cycle power plants, and even thermonuclear power plants, in which water is circulated around nuclear fuels, thus absorbing the heat produced in the reactions of these fuels to obtain hot steam, which is made circulate through turbines for energy use. These thermoelectric generation processes are cited by way of example, and without excluding existing ones or others not yet developed technically.

The low performance of these processes is explained in all cases by the laws of thermodynamics, and it is known or accepted that there are physical limits, derived from these laws, which prevent these yields from improving above theoretical values.

But also the laws of thermodynamics establish that the heat contained in these fluids that cannot be transformed into electrical energy is not lost in any case (Law of Conservation of Energy). As a real fact we have that, in all these processes, this excess heat has to be dissipated, since it cannot be used or stored. Thus, the use of cooling towers to evacuate that heat is frequent, and in other cases it is poured in the form of hot water to the sea or other water courses. In any case, there must be some way by which heat is evacuated.

In the case of systems that use water vapor as a thermal fluid, the residual heat is collected in the "CONDENSER", where it is transferred from the generation circuit to the refrigeration circuit. The result is generally hot water. The same is true in virtually all cases: hot water is obtained that is poured or cooled in some way so that it can recover its ability to act as a refrigerant, thus evacuating residual heat.

In all cases, and regardless of the method used for evacuation, there is a RESIDUAL HEAT that must be evacuated in any of the means developed by the technique.

THE NEEDS OF HEAT FOR HEATING.

The possibilities of using the waste heat of thermoelectric generation processes in heating systems, whether domestic or other facilities, are severely hindered in most cases by the low temperature of the refrigerants after use. This is because, in these industrial processes, to achieve high cooling rates in short periods of time and simple installations, large volumes of refrigerant are used, which undergoes a relatively high temperature increase. small, which leads to a very difficult use of this excess heat.

Although there are cooling systems capable of achieving a higher temperature of the refrigerants, they need large heat exchange circuits, usually in countercurrent, and which require huge contact surfaces. These exchange circuits have high installation and maintenance costs, which results in that, with very few exceptions, the excess heat that needs to be dissipated in these facilities has no use.

The use of excess refrigerant also has other advantages, such as the fact that its discharge into the environment has virtually no impact, or at least, this impact is barely appreciated. Thus, most industrial facilities with air cooling systems, and even the large water vapor cooling towers of thermal and nuclear power plants, are not considered as elements with high environmental impact, since the only element to be Yields to the atmosphere is low temperature air or water vapor also with a temperature much lower than that of boiling.

In addition, if the refrigerant used has a higher temperature, the losses in the transport circuit that must be from the generation facilities to the premises to be heated will increase significantly, or they will require installations equipped with a greater thermal insulation .

The consequence is that the temperatures of the refrigerants used are so low that their use for heating is, if unfeasible, at least uninteresting and employment only in places with high heating needs.

The temperatures of these refrigerants after their use in thermoelectric generation rarely exceed 40-60 ° C. However, the temperatures used in domestic heating circuits require, at the boiler outlet, values at least 65-75 ° C, to ensure good heating. Keep in mind that the aim of these heating systems is to reach temperatures of 20-30 ° C in the rooms, so the difference in the thermal jump between the rooms and the possible heating fluids in either case, changes from about 20 ° C to 40 ° C, that is, a difference almost double. In addition, in the path from the power plant to the premises to be heated there is a decrease in temperature, which will be below 40-60 ° C further away from the necessary temperature (65-75 ° C) for heating .

Special mention should be made of the fact that it is customary, in some places, to use this residual heat for heating, including the design of power plants specifically to use this heat for heating. However, to date there is no knowledge of its use with the help of heat pumps, this being the main novelty of the present invention.

THE HEAT PUMP.

On the other hand, the concept of HEAT PUMP is generally known as a means to transfer heat from a cold medium to a warmer medium, requiring an energy supply. exist different technical embodiments of the heat pump, and in this patent all of them are included, since they are different technical means to carry out a process well defined by science. Thus, it is defined as PUMP OF HEAT any process in which it is achieved that a body yields heat to another with a higher temperature, requiring for this the consumption of a certain amount of energy. It is about reversing, by any of the possible technical developments, the natural tendency by which heat passes from hot bodies to others of lower temperature. All existing processes, as well as all those that may be developed in the future, that are included in the HEAT PUMP concept are considered included in this patent.

DESCRIPTION OF THE INVENTION

The present patent consists in the use of the HEAT PUMP for the utilization of the RESIDUAL HEAT of the thermoelectric generation processes for heating of premises.

Within the concept of heating of premises, those places that need an adequate temperature for the comfort of people, the care and breeding of animal and plant species, as well as the conservation and treatment of products that require or benefit from temperatures are considered similar to those in the rooms for people.

This combination of using, through the heat pump, the residual heat of the thermoelectric generation processes, will be the one that leads to the use of this heat despite the fact that the temperature is insufficient for its use as a heater directly. Even in those places where this residual heat is already used for heating, the use of the heat pump will allow to reduce the temperatures of the transport circuits, reducing the losses in the transport and / or the insulation needs of the circuits of transport, without reducing the amount of heat provided to the premises to be heated.

The application of the present invention will require the union between the thermoelectric power plant and the premises to be heated by means of transport pipes for fluids that contain the residual heat of the power plants. These pipes will require more or less thermal insulation depending on the distance between both places and the temperature of the fluid, but they will be less than in the case of pretending to use these same fluids directly, without the use of the heat pump, thanks to the forced extraction of heat that it performs.

Obviously, the distance between these places will be a decisive factor for the applicability of this invention, although, in any case, its application will increase the possibilities of current use of waste heat from thermoelectric power plants.

DESCRIPTION OF THE DRAWINGS.

Figure 1 refers to the case in which the fluid that is obtained in the thermoelectric plant with the residual heat is water, which we will call Temperate Water of ATC Power Plant, and shows the process by which this ATC water is heated in the Heat Exchanger INT1 for gas hot GC that is obtained at the output of a COM compressor. The water is transformed into AC hot water, and the gas decreases its temperature but maintains a high pressure, and we call it Pressure Tempered Gas, GTP. The AC water will have sufficient temperature to heat the LC premises. After this, the water will have lost temperature, becoming temperate water, but different from the ATC warm water that came from the thermal power plant, which is why we call it the Second Tempered Water AT2.

On the other hand, the GTC Pressure Tempered Gas mentioned above, and which is the GC hot gas after heating the AC water, will expand until its temperature decreases, in a process similar to that produced by air conditioning, refrigerators and refrigerators . It thus becomes Cold Gas, GF. The cooling suffered must be carried out so that its temperature after expansion is significantly lower than that of the AT2 water leaving the LC heated room.

In a new heat exchange, represented in the figure as IT2, the GF Cold Gas and the Second Temperate Water, AT2, are joined, with the result that the cold gas is heated becoming Decompressed Tempered Gas, GTD, and the water it cools down definitively, becoming Cold Water AF, already dispossessed of its ability to provide heat and exhausted in this regard.

For its part, the Decompressed Temperate Gas will be passed through the COM Compressor again, where it will reach high pressure and temperature, until it becomes again the GC hot gas that will be used again to heat the ATC Central Temperate Water. In this way the gas is reused continuously, while the water tempered is cooled and evacuated from the circuit after having taken advantage of its caloric content.

EXHIBITION OF AN EMBODIMENT MODE.

To explain a simple way of carrying out the present invention, we start from the cooling water that leaves the condenser of a thermoelectric power plant that uses water vapor as an internal fluid. In the aforementioned condenser, this steam is cooled by means of the cooling circuit water, which in turn is heated, usually reaching temperatures between 30 and 70 ° C.

From this slightly hot water, and once it has been transported to the place to be heated, it will be passed through a heat exchange circuit. This exchanger will have as a hot element the gas from the outlet of a gas compressor used for air conditioning circuits. As a result, the water will be heated, and the gas will cool, but will maintain at least some pressure.

The heated water will be circulated through the heating circuit of the room to be heated, where it will give heat to the room, reducing its temperature. At the same time, the gas, after cooling with water, will be passed through an expander, where it will undergo significant cooling. The expansion of the gas will be such that its temperature is significantly lower than that of water, in a process well known and widely used in air conditioning, refrigeration and refrigeration systems. Once the cold gas is passed through a heat exchanger, next to the water already used in the heating circuit, giving place the cooling of the water, and the heating of the gas, which again leads to the aforementioned compressor.

For this embodiment of the invention, heat exchangers commonly used in air conditioning systems and compressors also widely used in these systems will be used.

Claims

1. System consisting of one or several HEAT PUMP units or any technical development that may be considered included in this concept or definition, used for the use of waste heat that is evacuated in thermoelectric generation processes for heating purposes.

REPLACEMENT SHEET (Rule 26)