WO1995014896A1

WO1995014896A1 - Process and device for converting electric power into useful heat

Info

Publication number: WO1995014896A1
Application number: PCT/DE1994/000669
Authority: WO
Inventors: Heinz Weiss
Original assignee: Sebacur Ag
Priority date: 1993-11-22
Filing date: 1994-06-15
Publication date: 1995-06-01
Also published as: AU6923594A

Abstract

In the process of the invention, oil is circulated in a sub-oil installation (8) in an open circuit and thus heated owing to the movement and the heat losses from the individual components in such a way that the energy stored in the oil in the form of heat can be transferred to heating systems. Here, the oil emerging from the gap between the stator (35) and the rotor (36) of the sub-oil electric motor (24) is taken in by the pump (21) driven by said motor (24) and returned to the oil bath (T) via a control valve (23). The oil is strongly heated on emerging from the control valve (23). This process virtually completely converts the electric power into heat. A heating installation for producing hot and heating water comprises a heat generator (1) operating according to the invention and conventional heat exchanger components for heating (6) and hot water installations (16). The process and the heating installation convert electric power into useful heat with an efficiency of over 98 %.

Description

Method and device for converting electrical

Energy in useful heat

The present invention relates to a method for converting electrical energy into useful heat and a heating system for the production of hot water and

Heating water using and using a hydro system.

In known hydro systems, energy is converted and transported. Hydrosystems as such have large ones

Advantages over other systems for energy conversion, since they allow a very high energy density. The electrical energy is converted into hydraulic energy by means of a motor-pump group. Arise in energy conversion and transportation

Losses, so that the temperature of the hydraulic fluid increases when mechanical and hydraulic energy is converted into heat. The ultimately achievable temperature of the hydraulic fluid is influenced by the heat supply and the heat dissipation, the heat supply being effected by a warm environment, power losses from internal leakages, power losses from chokes and power losses from flow resistances.

In known hydraulic systems, oil is fed from a large tank to a hydraulic system by means of a motor-driven pump, and the heated oil returned by the system is reintroduced into the oil tank via a heat exchanger.

REPLACEMENT LEAF The heat contained in the oil is removed from the hydraulic system through the heat exchanger.

The present invention is based on the object of specifying a method and a device which is improved with respect to the efficiency with regard to the energy used and removed compared to the known methods and devices.

According to the invention, this object is achieved by the method having the features of the main claim. Further advantageous refinements can be found in the subclaims.

In the method for converting electrical energy into useful heat, at least one sub-oil electric motor, which drives a hydraulic pump and at least one control valve downstream of the hydraulic pump, is arranged in a thermally insulated container filled with oil. All of these devices are completely in the oil bath. The sub-oil electric motor drives the hydraulic pump so that the oil is sucked out of the oil bath and released again into the oil bath by the control valve. The circulation of the oil converts the electrical energy supplied to the engine first into hydraulic and mechanical energy and then into heat, which is stored in the oil. Due to the arrangement under oil, the oil also gets into the gap between the rotor and stator.

According to a preferred embodiment of the method according to the invention, the oil emerging from the gap between the stator and rotor of the sub-oil electric motor is sucked in by the hydraulic pump and pressed back into the oil bath under pressure by the control valve. The control valve acts as a flow control valve, which regulates the oil flow depending on the viscosity of the oil, which is influenced by the temperature. When the oil escapes through an abces -irr-ir e

REPLACEMENT LEAF The outlet opening heats the oil due to the friction losses and is available as useful heat stored in the oil. This special design generates an optimum amount of heat in the control valve.

The method according to the invention transfers any heat loss generated in the open circuit to the oil and is available for further processing. According to a further advantageous embodiment, the sub-oil electric motor is operated at 1000 to 3000, preferably at 1500 revolutions per minute. The oil is circulated at a pressure of 160 to 250, preferably 170 bar.

Advantageously, the oil is filtered before entering the hydraulic pump to remove contaminants from the circuit.

According to a further advantageous embodiment, a hydraulic oil based on synthetic esters is used for environmental reasons, since this oil is biodegradable and cannot be combined with water.

In the method according to the invention, the oil is circulated in an open oil system in an open circuit and is heated due to the movement and the heat loss generated in the individual components such that the energy stored in the oil as heat can be given off to heating systems. The oil that emerges from the gap between the stator and the rotor of the sub-oil electric motor is drawn in by the pump driven by the sub-oil electric motor and returned to the oil bath via a control valve. This process almost completely transforms electrical energy into heat.

The task for the heating system for the production of domestic water and heating water is solved according to the Merkιτ ^* ä_.e: of claim 7. More beneficial

REPLACEMENT LEAF Refinements are in the corresponding back-related

Subclaims specified.

The heating system according to the invention has a heat generator, which comprises a thermally insulated housing, which is filled with oil, in which a hydraulic pump is arranged, which is driven by a sub-oil electric motor and which is followed by a control valve. The hydraulic pump sucks this out of the gap between the stator and rotor of the

Oil emerging from the sub-oil electric motor and releases the oil under pressure via the control valve back to the oil bath. The control valve regulates the oil flow depending on viscosity. The oil emerging through a defined outlet opening is heated as it exits. The cross section of the

Control valve depends on the dimensioning of the system in order to achieve optimal heating. The hydraulic pump is a conventional hydraulic pump that is connected to the sub-oil electric motor via a coupling. Sub-oil motors as such are known and are used, for example, in the conversion of electrical energy into hydraulic energy. For example, the use of a sub-oil motor in a hydraulic elevator in a building is known. In the case of sub-oil motors, the oil is forced to circulate in the gap between the rotor and the stator, the oil being passed over the stator packs. So there is an oil flood both in the "air gap" and on the stator package side, which enables uniform heat dissipation and prevents distillation of the oil in the gap between the stator and rotor. If dimensioned correctly, the better thermal conductivity of the oil can result in an increase in performance, which requires a higher magnetic and electrical utilization of the iron package or windings.

The heating system designed according to the invention further comprises at least one heat accumulator which has at least one heat exchanger in its interior

REPLACEMENT LEAF an oil supply and return line is connected to the heat generator. In addition, the heating system comprises at least one circulation pump that pumps oil from the housing of the heat generator through the oil lines and the heat exchanger. These devices are required in a known manner to indicate the heat absorbed by the oil to another medium. For this purpose, the heating system also has service and / or heating water pipes which are connected to the heat accumulator and dissipate the heat supplied to the heat accumulator. In addition, control devices are provided which control the heat generator in dependence on the heat dissipated. The control devices usually switch off the heat generator at a specific maximum temperature and switch it on again when the temperature drops below a lower limit.

In a preferred embodiment, the motor has swirl elements which promote the transport of the oil through the gap between the stator and the rotor. The torque characteristic curve of the sub-oil electric motor is thus changed by special cuts of the rotor and stator packages, so that a good efficiency is maintained at the nominal point in order to keep the losses and thus the partial heating in this area small. The swirl elements ensure good flow between the stator and rotor and counteract resinification of the oil.

According to a further advantageous embodiment of the heating system, devices are provided in the oil lines, at least in the area of the heat exchanger, which ensure a turbulent flow of the oil in this area. As a result, the heat dissipation of the oil in the heat exchanger is significantly improved, since the heated oil molecules can more easily reach the heat dissipation from the inside of the oil flow. The turbulent flow can be prevented by various measures, such as, for example, tubulators installed in the pipe which prevent the oil from swirling. or by other M≤ßna "- ^j r • -. r ^■ eicr .->.

REPLACEMENT LEAF become. Squeezes of the oil lines are preferably arranged at a distance from one another, so that the cross section in the interior of the oil line is reduced by these rapids and a turbulent oil flow is thus generated. This ensures optimal heat transfer from the oil to the medium in the heat accumulator.

To avoid contamination, the heating system also has a filter in front of the hydraulic pump.

The heating system designed according to the invention has an efficiency of greater than 98%. It is thus possible to use a domestic water and

Carry out heating water heating, which is for example above the efficiency of electric heaters. The device according to the invention is characterized by a simple and failure-prone conversion of the primary energy electricity into heat. All residual heat sources are used consistently in the system, so that a completely closed circuit is created with regard to the heat. The long service life of the hydraulic oil ensures a high temperature stability with great repeatability and a large heating reserve, even at low outside temperatures.

Depending on the required energy requirement, it is possible to arrange several such units in a lower oil housing. For example, the systems can comprise 2, 3 or 4 heat generation systems which, as described above, have a sub-oil electric motor, a hydraulic pump and a control valve connected downstream of the hydraulic pump. Systems designed in this way can be even more efficient and possibly have an even better efficiency.

REPLACEMENT LEAF The invention is described below using a

Execution example in connection with the accompanying

Drawings explained. Eε represent:

1 shows a functional diagram of a hydraulic

Heat generator;

Figure 2 is a hydraulic diagram of the heat generator and schematically the hydraulic pump and the sub-oil electric motor; and

Figure 3 is an illustration of the stator and rotor of the sub-oil electric motor.

As can be seen from FIG. 1, the heating system comprises the heat generator 1, which is connected to a heat accumulator 4 via a feed line 2 and a return line 3 for hydraulic oil. In the hydraulic oil feed line 2 there is also a circulation pump 5 for generating a

Forced circulation of hydraulic oil. The reference number 6 indicates in the heat exchanger coil 7 pinchings of the pipeline which ensure the turbulent flow of the oil in the pipelines in this area. The heat generator 1 and the heat accumulator 4 have a thermally insulated housing 8 or. 9 on.

On the heat accumulator 4, which is filled with water, a flow line 10 and a return line 11 for a heating system are connected. The heating system usually also comprises a mixing valve 12, a circulation pump 3 and one or more heat consumers 14. For safety reasons, there is also an expansion tank 15 in the feed line 10.

In addition, a further heat exchanger 16 for process water is arranged in the heat store 4, which is connected to a cold water pipe 17 and a process asserleitunα 18, which lead into the heated water * ^** . , <= -

REPLACEMENT LEAF There is also a thermometer 19 and a controller 20 on the heat store 4, the controller 20 usually ensuring that the heat generator is switched off when the temperature in the heat store has reached a predetermined value and switches on when the temperature of the water in the Heat storage drops below a counter value.

FIG. 2a shows the hydraulic diagram in the heat generator with a hydraulic pump 21, which is connected to a pressure relief valve 22, that for safety reasons it is installed in the system and ensures a constant pressure of 170 bar. Of the

Pressure-limiting valve, the oil delivered by the pump reaches the control valve 23, which regulates the flow of the oil depending on the viscosity of the oil. The special design of the outlet opening of the flow control valve as a function of the pressure in the system converts the friction which arises when it passes through the opening into heat. The heated oil comes out of the flow control valve 23 into the oil tank T, from where it is pumped through the circulation pump 5 to the consumer 30 and then returned to the tank T after cooling, and on the other hand from the hydraulic pump 21 after the Oil has flowed through the gap between the stator and the rotor of the sub-oil electric motor 24 to be pressed again by the control valve 23.

FIG. 2b shows a schematic representation of the sub-oil electric motor 24, which drives the hydraulic pump 21. In the area 25 of the sub-oil electric motor 24, the oil enters the gap between the stator and the rotor of the sub-oil electric motor 20 from one side identified by a spike, in order to then exit with a swirl at the point designated by the reference number 26 between the stator and the rotor. The exit there 0.: ■ ". '<: Üoer

ERSA _TZ SHEET a filter 27 sucked in by the hydraulic pump and via the

Line 28 to the pressure relief valve 22

Control valve 23 supplied. As can be seen from this hydraulic diagram, the heat-generating system is an open hydraulic circuit since oil escaping from the control valve 23 gets back into the tank T and can take two different paths from there. With the bracket 28, the unit can be attached to the housing. A commercially available, synthetic, ester-based oil is used as the oil.

In the case of the exemplary embodiment according to the invention, it has been shown that at a rotational speed of 1500 revolutions per minute and an operating pressure of 170 bar and with an outlet cross section from the flow control valve of 3.22 mm, optimal performance can be achieved with an efficiency of over 98%.

FIG. 3 shows the top view of a sub-oil electric motor 24, which is partially broken open and shown in section to show the swirl elements 31. The hydraulic pump 21 is connected to the lower oil electric motor 24 via a coupling arranged in the area 32. As can be seen from the figure, the oil enters the motor through openings 34 arranged on the end face 33 and enters the gap between the stator 35 and the rotor 36. The swirl elements 31 are essentially designed as inclined webs, between which grooves 37 for the oil run away. The oil entering at the end face is conveyed to the outlet openings 26 by the rotary movement of the rotor 36 via the oblique grooves 37. There it emerges from the sub-oil electric motor 24 and, as described in FIG. 2, is sucked in by the hydraulic pump 21 and transported further. In FIG. 3 the reference numbers 40 denε motor housing, 38 the winding package and 39 the motor shaft. The hydraulic side of the hydraulic pump 21 is 41 and m: ^** : 42 the pressure side.

REPLACEMENT LEAF

Claims

claims

1. A method for converting electrical energy into useful heat, in which in a thermally insulated oil-filled container (8) by means of at least one sub-oil electric motor (24) arranged in the oil bath, which drives a hydraulic pump (2), and at least one of the hydraulic pump (21 ) downstream control valve (23), the energy supplied to the engine is converted into heat stored in the oil.

2. The method according to claim 1, in which oil emerging from the gap between the stator and rotor of the sub-oil electric motor (24) is sucked in by the hydraulic pump (21) and pressed under pressure by the control valve (23) back into the oil bath, the oil is heated when passing through the control valve.

3. Method according to claim 1 or 2, in which the sub-oil electric motor is operated at 1500 revolutions per minute.

4. The method according to one of the preceding claims, in which the oil is rolled with a pressure of 170 bar.

5. The method according to any one of the preceding claims, wherein the oil is filtered before entering the hydraulic pump (21).

6. The method according to any one of the preceding claims, in which a hydraulic oil on a synthetic ester base is used.

7. Heating system for the production of domestic water and / or heating water with

a heat generator (1) which has a thermally insulated housing (8) which is filled with oil, in which a hydraulic pump (21) is arranged which is driven by an under oil electric motor (24) and which is followed by a control valve (23) is, the hydraulic pump (21) sucks in the oil emerging from the gap between the stator and the rotor and releases it under pressure via the control valve (23) back to the oil bath and the control valve (23) regulates the oil flow depending on viscosity and the oil at the outlet due to a predetermined outlet cross section heated,

at least one heat accumulator (4), which has in its interior at least one heat exchanger (7), which is connected to the heat generator (1) via an oil feed line (2) and an oil return line (3), and at least one circulation pump (13), which Oil from the housing (8) deε

Pumps heat generator (1) through the oil line (2, 3) and the heat exchanger (7),

Service water pipes (17, 18) and / or heating water pipes (10, 11) which are connected to the heat accumulator (4) and which dissipate heat supplied in the heat accumulator (4), and

Control devices (19, 20) which control the heat generator (1) depending on the heat dissipated.

8. Heating system according to claim 7, wherein the sub-oil electric motor (24) has swirl elements; ^* :: - c →▶ -. v.

REPLACEMENT LEAF Promote the transport of the oil through the gap between the stator and rotor.

9. Heating system according to claim 7 or 8, wherein the

Oil lines (2, 3) at least in the area of the heat exchanger (7) have devices (6) which ensure a turbulent flow of the oil in this area.

10. Heating system according to one of the preceding claims 7 to 9, which includes the devices (6) for the turbulent flow at a distance from each other bruises of the oil distribution, so that the cross section is reduced by rapids inside the oil line.

REPLACEMENT LEAF