SE543778C2 - Condensation motor with energy storage unit - Google Patents

Abstract

The invention relates to a condensing motor (10), comprising, a cylinder (12) and a piston (18) arranged in the cylinder, which piston is attached to a piston rod (22) which runs through a bushing in an end end (14) of the cylinder (12). . It also has liquid containers (30) containing evaporable liquid medium (31) arranged at each end of the cylinder (12) and in fluid communication with the interior of the cylinder. A heating means (32) is arranged in heat transfer contact with the respective liquid container (30). A cooling device (44, 46) is arranged to cool the cylinder (12) and thereby cause the evaporated liquid medium (31) to condense. A control unit (60) is configured to control the heating means (32) to synchronously and alternately heat the liquid medium (31) in the liquid containers (30) to effect an evaporation of the liquid medium (31) in one of the containers (30). Thereby, the pressure in the cylinder on one side of the piston (18) increases and presses it from a first position in the cylinder (12) to a second position and after the liquid medium has condensed. The heating also causes an evaporation of the liquid medium (31) in the second container (30) so that the pressure in the cylinder (12) increases on the other side of the piston (18) so that it is forced back to the first position from the second position. The invention also relates to a power plant, comprising a condensing motor according to the above connected to any of a wind turbine, a solar cell plant or a wave power plant.

Description

CONDENSING ENGINE WITH ENERGY STORAGE UNIT The invention refers to a type of condensing engine based on the Rankin cycle where energy for operation comes from an external source, for example from solar energy or wind power.

Background of the invention Solar, wave and wind power are internal power sources, ie the near sun does not shine or the wind does not blow, no energy is supplied. Conversely, when the sun is shining and the wind is blowing, there may not be a need to take any effect. Thus, it would be desirable to have energy storage systems from these systems.

Examples of energy storage can be ultracapacitors, rechargeable batteries, mechanical storage in the form of positional energy, and more.

However, these systems all have their shortcomings in terms of efficiency or complex design.

Summary of the Invention The present invention seeks to provide an alternative to known systems.

The invention is defined in claim 1 and preferred embodiments appear from the dependent claims.

Thus described here is a condensing motor (10), comprising, a cylinder (12) and a piston (18) arranged in the cylinder which piston is attached to a piston rod (22) which runs through a bushing in an end end (14) of the cylinder (12). ). It also has liquid containers (30) containing evaporable liquid medium (3 l) arranged at each end of the cylinder (12) and in fluid communication with the interior of the cylinder. A heating means (32) is arranged in heat-transferring contact with the respective liquid container (30). Cooling device (44, 46) is arranged to cool the cylinder (12) and thereby cause the evaporated liquid medium (3 L) to condense. A control unit (60) is configured to control the heating means (32) to synchronously and alternately heat the liquid medium (3 1) in the liquid containers (30) to cause an evaporation of the liquid medium (3 1) in one of the containers (30). one side of the piston (18) and the press antenna from a first position in the cylinder (12) to a second position and after the liquid medium has condensed. The heating also causes an evaporation of the liquid medium (31) in the second container (30) so that the pressure in the cylinder (12) increases on the other side of the piston (18) so that it is forced back to the first position from the second position. aspect, a power plant is also provided, comprising a condensing motor according to the above connected to any of a wind turbine, a solar cell plant or a wave power plant.

The invention is further elucidated in the following with reference to the accompanying drawings in which Fig. 1 shows a condensing motor and an energy storage unit schematically; Fig. 2 shows the engine cylinder in cross section; Fig. 3 shows an embodiment of the energy storage unit; Fig. 4 schematically shows the operation of the engine; and Fig. 5 shows the control system schematically.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS Fig. 1 shows an embodiment of a condensing motor 10 according to the invention.

The motor comprises a closed cylinder 12 which preferably has a circular cross-section, and has end walls 14, 16. In the cylinder a piston 18 can be caused to run in a reciprocating motion. The piston has a gas-tight bushing 20 in one of the end walls of the cylinder where a piston rod 22 runs, which piston rod is connected to the piston 18 inside the cylinder.

The piston rod can be coupled to a flywheel (not shown in Fig. 1) or other rotatable element via an articulated arm for transmitting the linear movement of the piston and the piston rod to a rotational movement.

The inner friction of the cylinder is very low and the cylinder is for this purpose preferably built up of an outer jacket 24 of, for example, copper, and an inner tube of glass 26, see Fig. 2. In the space between glass and copper, elongate support elements 28 arranged in the longitudinal direction of the cylinder distances from each other in the circumferential direction. In the embodiment shown, there are eight support elements, but this number is not critical. The support elements are preferably made of PVC plastic.

The piston 18 in this embodiment, in which the cylinder has a volume of about 5 liters, is designed as a thin plate with an O-ring 19 along its peripheral seal against the glass walls. The O-ring is preferably made of PVC plastic. The thickness T of the plate is preferably about 10 mm, but can vary between 5 mm and 50 mm. Of course, the dimensions of the piston will be different at other cylinder sizes.

At each end of the cylinder there is a container 30 for the liquid medium 31 which is to drive the engine. In the embodiment shown, the containers hold approximately 3.5 ml of evaporable liquid each. This volume is adapted to the volume of the cylinder which in the example shown is approximately 5 dmß, which is the volume occupied by evaporated liquid medium. For larger cylinder volumes, of course, more liquid medium is required. The containers 30 are suitably of a material with good thermal conductivity, such as metal, so that the heating of the liquid medium can take place very quickly.

Adjacent to the motor there is preferably a heat storage unit 32 for storing heat, generated for example by electric heating where the electricity can be generated with solar energy or wind energy or other intermittent energy, but for the purpose of heating the method of supplying energy to the motor is insignificant. It is possible to use direct heating with other devices, but to provide a single storage unit for heat enables operation even when a continuous supply of energy is not available.

In the embodiment shown, the heat storage unit comprises a steel tube 34 which weighs about 50 kg and which can be heated up to about 1500 ° C. This tube can advantageously be made of stainless acid-proof steel. The heating preferably takes place with an electrically driven heating cartridge (not shown), but other ways are conceivable. As mentioned above, electrical energy to the heating cartridge can preferably be supplied with solar cells, wind power, or from other intermittent energy sources.

The steel pipe is arranged in a very well insulated space 36, preferably ceramic material or the like with additional insulating material 37 arranged around the unit. Insulation is shown schematically with a dashed contour line. The insulating material should preferably be aerogel which has extreme insulating ability. Such material may be provided by Svenska Aerogel AB. Other insulation materials are of course also conceivable.

Inside the storage unit there is a preferably inert gas medium 38, for example nitrogen, but it can also consist of some other gas such as a noble gas. Air can also be used unless the oxygen in the air is suspected to pose a risk of undesired oxidation effects.

The heat storage unit 32 is used to heat the liquid medium in the said containers. For this purpose, there is a channel 40 from the interior of the storage unit 32 which extends to the bottom of the respective container 30 for liquid medium.

A valve (indicated by an arrow through the duct 40) arranged in the respective duct 40, which is controlled by a central control unit, is opened and closed synchronously to let a sufficient amount of hot gas into the duct so that the bottom of the containers comes into contact with the hot gas and very quickly heats the liquid 31 in the containers 30. A construction of this heat transfer mechanism will be described in more detail below.

Furthermore, there is a non-return valve 42 at each end of the cylinder, the function of which is described below in connection with a description of the operation of the engine.

The liquid medium used should preferably have a low boiling point, preferably in the range 35-40 ° C, although other liquids with a higher boiling point are conceivable. A suitable liquid medium has a boiling point of 37 ° C. Liquids with a high boiling point are possible, for example water could be considered. The special feature is that the liquid has a lubricating ability to further reduce the friction in the system.

In Fig. 2, the cylinder 12 is shown in cross-sectional view. The cylinder 12 is suitably surrounded by a cooling jacket 44 which preferably utilizes cooling by means of cooling coils running in the ground in connection with the installation, in which a suitable cooling medium 46, for example water, is circulated. Thermostat control ensures that the internal temperature of the cylinder is kept at a desired level, ie maximum immediately above the boiling point of the liquid medium.

Fig. 3 shows an example of an embodiment of the heat storage unit 32 and the mechanism for effecting evaporation of the liquid medium. The surrounding insulation 37 indicated in Fig. 1 is not included in Fig. 3 for clarity reasons.

The steel pipe 34 is thus enclosed in an insulated housing 36. Inside the pipe 34 there is arranged a preferably electric heating element 48 which can be driven by an external energy source, for example solar cell electricity or electricity from wind power.

The steel pipe 34 is heated to a high temperature in the range 1000 - 2500 ° C and the casing thus has, as mentioned, a gas atmosphere 38 which assumes the same temperature.

Through an insulating wall 50 at each end of the housing 36 runs a heat transfer device 52 in the form of a rod or the like with high thermal conductivity, for example a metal rod, suitably of steel. These heat transfer devices 52 heat the atmosphere in a respective intermediate space 54. These intermediate spaces are in direct communication with one or more end spaces 56 via valves 58a, 58b. The end spaces 56 in turn are in direct heat transfer contact with the containers 30 of pre-liquid medium. By opening and closing the valves 58a, 58b synchronized in a controlled manner, preferably controlled by temperature, the liquid medium in one container 30 can be caused to evaporate very quickly and thereby rapidly expand, and flow into the cylinder 12 (indicated by a broken line) and actuate the piston 18. to move in the cylinder. The second valve 58b is closed during the evaporation process which is initiated by opening the first valve 58a, and is thus opened when the piston 18 is moved to its end position by means of the expanded gas in the first evaporation.

Operation of the motor as above will now be described in more detail with reference to the schematic Figs. 4a-d.

In the rest position, Fig. 4a, before start-up, the pressure in the cylinder 12 is equal on opposite sides of the piston 18, i.e. P = P0.

When one of the valves in the heat storage unit is opened, the liquid in the container will evaporate very quickly and expand so that the piston will be pressed towards its second end position by the pressure increasing and becoming Po + A, Fig. 4b. In order for this to take place in the start-up phase, the entry pressure equalization valve TUV is opened at the other end of the cylinder so that the pressure is equalized and the piston can reach its end position without resistance. The pressure in the cylinder will thus remain P0 on the opposite side of the piston.

As mentioned, there is a cooling jacket arranged around the cylinder (visually schematic with large arrows), which provides a very rapid cooling of the expanded steam in the cylinder so that the pressure increase A is very quickly reduced back to P0 by condensing the liquid, Fig. 4c. This condensation preferably takes place in about 0.1 second in this embodiment.

Thus, when the piston has reached the end position in the first stage, the pressure relief equalizing valve TUV and the second valve in the other end of the heat storage unit are opened to evaporate the liquid in the second container, Fig. 4d. Thanks to the condensation of steam on the opposite side, the process from the first initial step will therefore be repeated in the opposite direction, i.e. the expanding gas now pushes the piston valve back to the first position. In this second step, however, the non-pressure equalization valve thus needs to be opened because the condensation of the steam repressurizes to P0.

In the embodiment shown, the cylinder has been shown with a circular cross-section. However, other cross-sections such as triangular, rectangular or polygonal cross-sections can be used.

The illustrated embodiment of heat storage and heating mechanism is merely an example, and this can be done in many ways. The essential pre-invention is that there must be a regulation of the heat supply to the liquid containers which takes care of alternating opening / closing of the valves in a synchronous manner so that expansion / condensation of the steam takes place in an optimal manner.

The system is controlled by a control unit 60 in the form of a microprocessor. The control is shown schematically in Fig. 5.

All valves 40; 42, 58a, 58b in the system are activated by the control unit 60. The control can be based on pressure and temperature measurements via sensors Spysom can be arranged in the cylinder 12 and at other suitable places in the system, and whose signals are fed to a control algorithm in the control unit these regulate the operation by synchronized opening and closing of the valves.

The condensing motor 10 as described above is suitably connected to a generator for generating electrical energy, whereby intermittent energy can be stored and used in an advantageous manner when, for example, a wind turbine stands still due to it not blowing.

The condensing motor 10 can thus be used in a power plant where intermittent energy can be stored and utilized when needed, by connecting it to one of a wind turbines, a solar cell plant or a single-wave power plant.

Claims (6)

: A condensing motor (10), comprising, a cylinder (12), a piston (18) arranged in the cylinder which piston is attached to a single piston rod (22) running through a bushing in an end end. (14) of the cylinder (l2); characterized by liquid containers (30), containing evaporable liquid medium (31), which are arranged at each end of the cylinder (12) and in fluid communication with the interior of the cylinder; a turning means (32) arranged in heat transfer contact with the respective liquid container (30) via channels (40) running the interior of the unwinding means (32) to the bottom of the respective container (30); a cooling device (44, 46) arranged to cool the cylinder (12) and thereby cause the vaporized liquid medium (31) to condense; a control unit (60) configured to control the heating means (32) to synchronously and alternately heat the liquid medium (31) to cause the liquid containers (30) to evaporate the liquid medium (31) in one of the containers (30) so that the pressure in the cylinder increases on one side of the piston (18) and presses it from a first position in the cylinder (12) to a second position and after the liquid medium has condensed, cause an evaporation of the liquid medium (31) in the second container (30) so that the pressure in the cylinder (12) increases on the other side of the piston (18) so that it is pressed back to the first position from the second position; and in that the heating means (32) is a heat storage unit (34, 37, 38, 48, 52, 54, 56, 58a, 58b) connected to an intermittent energy source, and that the heat storage unit comprises a steel pipe (34); an electric heating device (48) driven by the intermittent energy source and arranged to heat the steel pipe (34), preferably up to 1500 ° C; wherein the steel tube (34) is enclosed in an insulated space in which a gas is present; and a valve arrangement (54, 56, 58a, 58b) arranged in the respective channel (40), which is controlled by the control unit (60) to provide the synchronous and alternating heating of the liquid medium (31). Condensation motor, according to claim 1, wherein the cylinder (12) comprises an inner tube (26) of glass in which the piston (18) runs, an outer jacket (24) of metal, preferably copper, a number of support elements (28) arranged in a space between the glass tube (26) and the outer jacket (24), and a cooling jacket (44) surrounding the outer jacket (24). Condenser motor, according to claim 2, wherein the support elements (28) are elongate and arranged in the longitudinal direction of the cylinder. A condensing motor according to any one of the preceding claims, comprising sensors (Spçr) for measuring pressure and temperature where the control unit (60) is configured to receive signals from these sensors and in response to the signals regulate the operation according to a control algorithm. A condensing motor, according to any one of the preceding claims, wherein the intense energy source is solar cells, wind power or wave power. A power plant, comprising a condensing motor according to any preceding claim connected to any of a wind turbine, solar cell plant or a wave power plant, for supplying the heating means with electrical energy.