WO2013019094A1 - Method for producing heat energy from electric energy and device for carrying out said method - Google Patents

Abstract

The invention relates to heat and power engineering and to heat-exchange technology, and specifically to heating a liquid medium, and can be used for producing hot water for domestic requirements. The method for producing heat energy from electric energy comprises arranging an electric heating element in the vicinity of a heat-accumulating substance in a housing insulated from the surrounding space, wherein, in the geometrical centre of the housing, which is filled with a heat-transfer agent, a pipe in the form of a rising spiral is laid uniformly around the heating element, with the medium to be heated being passed through said pipe, and heat being transferred from the heating element to the liquid to be heated through the pipe walls by means of the heat-transfer agent which is in the solid state of aggregation and fills the free space around the heating element and the pipe for the passage of the medium to be heated, and a dry granular mix is used as the heat-transfer agent. The invention also relates to a device implementing the method. The technical result consists in reducing the consumption of electric energy and the specific power of the heat energy source by using a dry granular mix as the heat-transfer agent (heat-accumulating medium).

Description

 METHOD FOR PRODUCING THERMAL ENERGY FROM ELECTRIC AND DEVICE FOR ITS IMPLEMENTATION

The invention relates to a power system and heat exchange technology, namely to heating a liquid or gas medium and can be used, in particular, to produce hot water for domestic use.

 There is a method of producing thermal energy from electrical energy for heating, which consists in taking a heating element, placing it in the surrounding space, applying an electric current and bringing the heating element to a bright glow, turning on the electric fan, blowing the surface of the heating element and heating the room air (Lepaev D .A. Handbook for the repair of household electrical appliances and machines. - M.: Legprombytizdat, 1988, pp. 51-52).

 However, the method is characterized by low efficiency due to the high energy consumption; small heat removal per unit time due to the small heat removal surface; low efficiency. In addition, the use of an open heating element, such as nichrome, degrades the quality of the air in the heated room.

 There is also a method of producing thermal energy from electrical energy for heating, which consists in taking a heating element, surrounding it with a solid heat-accumulating substance, for example, powdery quartz sand, isolating all this from the environment with a heat-removing surface, for example, of a tubular type, and a device of the type TEN, they bring an electric current to it and heat the environment, such as water, with the heat released (Kitaev E.V., Grevtsev NF Course in General Electrical Engineering. - M: Soviet Science, 1945, p. 27).

The disadvantages of this method are the high energy consumption; small heat removal per unit time due to the small heat removal surface; low efficiency and high values of specific power.

 A device is known for cooling or heating gaseous media (RF patent JY "2299380, publ. 05.20.2007).

 This device contains a thermally insulated tank with inlet and outlet nozzles, between which an accumulating substance is placed in the form of granules of various diameters.

 The disadvantages of the device is that it is used to heat a gaseous medium and is not suitable for heating water, as well as the cyclical nature of the heat exchanger.

 Known instantaneous electric heater (RF patent JV ° 2269068, IPC F24H1 / 20, publ. 2006.01.27). According to this invention, in a flow-through electric heater containing a housing, a heat exchange module is installed in the housing, consisting of a casing with a tubular electric heating element inside and connected to the inlet and outlet pipes, a pressure switch, a thermal switch, light-signal fittings, according to the invention, the casing of the heat exchange module is formed tightly interconnected panels, in each of which stampings are made adjacent when the panels are connected to each other and forming channels for the passage of liquid and installation of the tubular electric heating element, wherein the shape and length of the channels correspond to the shape and length of the electric heating element.

 The disadvantage of this heater is the difficulty of manufacturing, high consumption of electrical energy.

The closest technical solution of the claimed invention for the combination of essential features is a method of obtaining thermal energy from electrical energy, including the placement of resistive an electric heating element surrounded by a heat-accumulating substance, isolated together with an electric heating element in its volume from the surrounding space with a heat-removing surface to form a heating device, placing the obtained one or more heating devices in the surrounding heated space, supplying electric energy to the electric heating element and washing the heat-removing surface of the device with a coolant, which used air from the room. In this case, solid (inside) the surface of the electric heating element and gaseous outside the surface of the electric heating element (air) gas are used as the heat storage substance; an increase in the total working heat removal of the heating device as a whole is achieved due to the interconnected increase (development) in the initial surface area of the heat removal of the electric heating element and the gaseous volume heat-accumulating substance around it, the area of the heat-removing surface itself is heating about the device, through the creation of a gap (distance) between these working surfaces due to the intensity of washing the heat-removing surface of the heating device with air from the room, and also by adjusting the parameters of the electric current on the electric heating element, (RF patent 2151346, IPC F 24 N 7/00, 7 / 02, 7/04, publ. 06/20/2000, bull. 17).

 The disadvantages of the known method of producing thermal energy from electricity are high power consumption and the inability to use for domestic hot water.

The closest technical solution of the claimed invention on the set of essential features is also a device for generating thermal energy from electric - in-line electric water heater (EVN) "THERMEX Stream" (in-line water heater "THERMEX Stream". Operation manual) intended for hot water for domestic purposes.

 An electric water heater consists of a housing inside which a copper cylinder with heating elements is installed, an inlet pipe for cold water, an outlet pipe for hot water, a pressure switch and a thermal fuse. Depending on the installation location, a shower head or a spout (kitchen faucet) may also be included in the EVN kit. Water is heated passing through a copper cylinder in which the heating elements are located. The required temperature is achieved by adjusting the flow of water. After supplying water to the power supply and setting the minimum permissible pressure (0.05 MPa), the pressure sensor will automatically turn on thermoelectric heaters (TENs), as indicated by the glow of the indicator of the network power button. When the hearth pressure at the inlet decreases below the minimum allowable pressure sensor will turn off the heating elements, respectively, the indicators will go out, heating will stop. To protect against overheating of water, the EVN is equipped with a thermal fuse mounted on a copper cylinder.

 The disadvantages of this instantaneous water heater are:

 1. High energy consumption from 3.5 to 7.0 kW.

 2. The instantaneous water heater is installed only at one point of the water supply system - in the kitchen or in the bathroom, it must not be "embedded" in the system to receive hot water in all taps in the apartment.

 3. Electrically unsafe since in the event of a short circuit, contact of electricity with heated water may occur.

In addition, the common disadvantages of instantaneous electric water heaters are low productivity, difficulty in operation (requires special electrical wiring, it is difficult to regulate water temperature) and a narrow temperature range of heated water (from 16-18 ° C to 35 ° C).

 The problem to which the proposed group of inventions is directed is to create a method and an electrically safe device for heating water using a flow system for moving the heated medium, with reduced power consumption, high productivity, easy to operate, providing a wider temperature range of the heated water.

 The technical result achieved by the implementation of the claimed group of inventions is to reduce the consumption of electricity and specific power of the source of thermal energy due to the use of a dry bulk mixture as a heat carrier (heat storage medium).

 The specified technical effect is achieved by the fact that in a known electric heater containing a housing, an electric heating device installed in the housing, inlet and outlet pipes, a channel for the passage of liquid, a pressure switch, a thermal switch, light-signal fittings, according to the invention, the channel for the passage of the heated medium is a metal pipe, laid around an electric heating device in the form of an ascending spiral, and the free space of the device case is filled with coolant (heat kkumuliruyuschim substance), which as a dry granular mixture, for example a river or sea sand can be used.

According to the invention, an electric heating device (TEN) is installed in the center of the device for receiving thermal energy from electric energy in the center, a pipeline with a heated medium is additionally laid around it in the form of an ascending spiral, the remaining free space is filled with coolant (heat-accumulating medium), while the heat transfer is due to heat transfer from the heated volume of the coolant to the surface of the pipeline with the heated medium.

 The use of a dry bulk mixture as a coolant (heat-accumulating medium) instead of directly heating the medium passing through the pipeline through an electric heater makes it possible to reduce electric energy consumption by using the energy of stored heat by 3-4 times, ensures electrical safety of the device due to the absence of electrical contact between the heating device and pipeline with a heated medium.

 As an insulating material to isolate the device from the external environment, you can use any insulating material.

 The device provides hot water with temperatures up to 100 ° C, you can get steam.

 The performance of the device depends on the water pressure in the system and can reach 10-12 l / m, i.e. provides hot water in an amount sufficient for washing dishes, washing in the shower, as well as for taking a bath.

 The device can be used wherever hot water is required, as well as where heating of other liquids is required, including caustic and toxic, as well as gaseous media, such as air.

 A method of producing thermal energy from electrical energy can be used in dishwashers and washing machines, subject to minor structural changes. In this case, heaters of lower power can be used.

 The practical dimensions of the device can be 200 x 180 x 90 mm.

Power consumption - no more than 1, 5 kW. The device is convenient to use - there is no need to conduct special wiring, because the device operates from a conventional power outlet. In addition, the device is easily connected to the existing water supply system, in particular, to the hot and cold water mixer, while the existing electric water heaters are equipped with their own hose and a special shower device in the event of which the operation of the water heater becomes impossible, because You can’t buy it and replace it with another.

 Cold water is heated by heat transfer from the heated surface of the dry bulk mixture to the surface of the pipeline with a heated medium. The optimal heating of the electric heating device is 30% higher than the required temperature of the heating medium.

 An increase in the total working heat removal is achieved by placing a pipeline with a heated medium in the form of a spiral laid around the heating device and, as a result, increasing the initial surface area of the heat transfer removal and completely filling the entire free volume of the device body with a heat carrier (heat storage substance).

 In an example implementation of the method and device for generating thermal energy from electrical energy, cold water, thermoelectric heaters (TENs) were used, river sand and other materials were used as a dry bulk mixture. The test results showed that the amount of hot water at the outlet of the device (capacity, l / min) with low power consumption depends on the pressure of the cold water supply.

The proposed method for producing thermal energy from electrical energy and a device for its implementation are illustrated in the drawing, where figure 1 schematically shows a General view of the device. A device for implementing a method of generating thermal energy from electric energy comprises a housing 1 with a cover 2, a pipe 3 for cold water inlet and a pipe 4 for hot water outlet, an electric heating device 5, a pressure switch 6. The housing has thermal insulation 7. All free space of the housing is filled with coolant 8 - dry bulk mixture that acts as a heat-accumulating substance. The heated medium is passed through a pipe 9 laid around an electric heating device in the form of an upward spiral.

 The electric heating device 5 is connected to a water pressure switch 6, a temperature controller, a light-signal indicator, and contains power terminals (not shown).

 The device is powered from a 220 V power supply network, an industrial frequency of 50 Hz.

 Cold water is supplied to the inlet pipe 3, while the pressure switch 6 is activated, includes a micro switch (not shown), which closes the electrical network, including the electric heating device 5. The light-signal indicator is turned on, informing the consumer about the working state of the device. When the liquid pressure in the network decreases or is absent, the pressure switch 6 activates and switches off the power supply of the electric heating device 5. By means of a microswitch, cold water passing through the pipe 9 is heated to the required temperature due to the heat accumulated by the heat carrier. Hot water is discharged through pipe 4.

The supply of electric current to the electric heating device is controlled by a temperature regulator (not shown), which, when the set temperature of the liquid is reached, turns off the power to the control electrode of the semiconductor device (thyristor) through which it passes electric current to the electric heating device, and when the temperature of the liquid decreases, it turns on the power supply. The control circuit also includes a pressure switch that turns off the water heater in the absence of fluid pressure, or at overpressure.

 As an electric heating device 5, a thermoelectric heater (TEN) can be used.

 A method of obtaining thermal energy from electrical is as follows.

 When you turn on the device in the network, the electric heating device 5 is heated to a temperature 30% higher than the required temperature for heating the water. The heat carrier (heat-accumulating substance) - dry bulk mixture 8 accumulates heat, which is then absorbed by the heat-removing surface of the pipeline 9, which is immersed in the dry bulk mixture. Heated water moves along the outlet pipe 4 to the consumer.

 The achievement of the specified technical result is ensured only with strict inextricable and interconnected implementation of all the essential features of the claimed group of inventions. In addition to the indicated technical result achieved, it is also necessary to note the following advantages of the proposed device in comparison with the prototype and analogues: high efficiency; low power consumption; low specific power; adjustable amount of heated coolant; electrical safety due to the lack of electrical contact between the heated water and the electric heating device.

Thus, the above information shows that when implementing the claimed group of inventions, the following conditions are met: - the method and device embodying the invention in their implementation, are intended for use in everyday life for hot water supply;

 - for the claimed inventions in the form as described in the independent claims, the possibility of their implementation using the described or other means and methods known before the filing date of the application is confirmed;

 - means embodying the invention in their implementation, are able to provide the specified technical result.

 Therefore, the claimed invention meets the condition of patentability "industrial applicability".

 The advantages of the claimed instantaneous electric water heater is:

 - electrical safety, due to the lack of electrical contact between the heated fluid and the electric heating element;

 - less energy consumption, minimum power consumption leaves 1.5 kW, while existing electric heaters consume from 3 kW and more;

 high productivity up to 12 l / min. With this performance, you can collect a bath and wash in it;

 - simplicity in operation. The electric heater is connected to a hot and cold water mixer, while existing water heaters provide their own hose and shower head. In addition, the inventive water heater does not require special electrical connections and can operate from an ordinary 220 V outlet;

- a wider temperature range of heated water. If existing instantaneous water heaters heat water to a temperature of 35 ° C, then the claimed can heat water to a boil. The device is reliable, technologically advanced.

 The use of the proposed group of inventions for hot water supply will ensure the production of hot water through the use of effective heat storage material and increase heat storage surface; reduce energy consumption by 5-10 times compared with well-known technical solutions; increase the service life of the device, as heating takes place in a closed heat-insulated space, which accelerates the entire heating process to preset temperatures; create an electrical safety heater with high efficiency.

Claims

CLAIM  1. A method of generating thermal energy from electrical energy, comprising placing an electric heating device in the environment of a heat-storage substance, isolated together with an electric heating element in its volume from the surrounding space with a heat-removing surface to form a heating device, placing the resulting heating device in a surrounding heated space, supplying an electric heating element energy and the surrounding surface of the heating surface coolant system, characterized in that in the heated space filled with the coolant additionally place a pipe through which the heated medium is passed, the pipe is laid around the heating device in the form of an ascending spiral, heat is transferred from the heating element to the heated fluid through the pipe wall through the coolant in the solid state of aggregation, and filling the free space around the heating device and pipelines for the flow of the heated medium, and as a coolant use a dry bulk mixture  2. A method of producing thermal energy from electric energy according to claim 1, characterized in that a dry bulk mixture is used as a heat carrier (heat storage substance)  3. A method of producing thermal energy from electrical energy according to claim 1, characterized in that a liquid or gaseous medium can act as a heated medium 4. A device for generating thermal energy from electrical energy, comprising a housing, in the inner chamber of which is placed an electric heating device connected to a power source, input and output pipes, a pipeline for the flow of heated medium, pressure switch, thermal switch, light-signal armature, characterized in that the electric heating device is located in the geometric center of the housing chamber, the pipeline for the flow of the heated medium is evenly laid around the electric heating device in the form of an ascending spiral, the free space of the housing chamber is filled with a coolant (heat-accumulating substance) from which thermal energy is transferred to the heated medium, and the pressure switch, thermal switch, light-signal fittings are placed in the self solid block.  5. A device for generating thermal energy from electric energy according to claim 4, characterized in that a dry bulk mixture is used as a heat carrier (heat storage substance)  6. A device for generating thermal energy from electrical energy according to claim 4, characterized in that the housing is made in the form of a rectangular parallelepiped  7. A device for generating thermal energy from electrical energy according to claim 4, characterized in that the electric heating device is a dark electric heater TEN.  8. A device for generating thermal energy from electrical energy according to claim 4, characterized in that the housing is coated on the inside with a heat-insulating material.