WO2013109152A1 - Moteur thermique externe et procédé d'exploitation d'un moteur thermique externe - Google Patents

Moteur thermique externe et procédé d'exploitation d'un moteur thermique externe Download PDF

Info

Publication number
WO2013109152A1
WO2013109152A1 PCT/NO2013/050013 NO2013050013W WO2013109152A1 WO 2013109152 A1 WO2013109152 A1 WO 2013109152A1 NO 2013050013 W NO2013050013 W NO 2013050013W WO 2013109152 A1 WO2013109152 A1 WO 2013109152A1
Authority
WO
WIPO (PCT)
Prior art keywords
heat
external
fluid
cylinder
working
Prior art date
Application number
PCT/NO2013/050013
Other languages
English (en)
Inventor
Harald Nes RISLÅ
Original Assignee
Viking Heat Engines As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Viking Heat Engines As filed Critical Viking Heat Engines As
Publication of WO2013109152A1 publication Critical patent/WO2013109152A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
    • F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00—Combustion technologies with mitigation potential
    • Y02E20/14—Combined heat and power generation [CHP]

Definitions

  • An external-heat engine that uses a working fluid is described, in which at least one variable-volume chamber is formed by at least one unit, and in which, for at least one of the at least one variable-volume-chamber-forming unit, at least one thermal barrier is arranged, preventing heat flux from the at least one variable-volume-chamber- forming unit into at least one surrounding unit and/or the surroundings.
  • thermodynamic process for the operation of an external-heat engine is described as well.
  • thermodynamic process for the operation of a combined heat and power plant is described.
  • External-combustion engines or more generally external-heat engines such as steam turbines, utilize the heat from, for example, coal combustion, waste combustion, nuclear processes et cetera, and cools away the residual heat into the surroundings by means of a condenser or at worst as in some older steam engines, in which the steam, after having been used to create work on a piston, is vented straight into the atmosphere.
  • Tc is the absolute cold-reservoir temperature, in Kelvin (or Rankine)
  • Th is the absolute heat-reservoir temperature.
  • biomass burners that is to say pellet and wood-chip burners
  • thermal solar collectors that is to say solar collectors that only supply heat
  • some of these technologies have become capable of supplying heat at relatively high temperatures, for example up towards 200-300 °C. Even if these temperatures are considered to be high in this connection, they are still low in relation to the temperatures achieved through combustion processes, as these are often 800-900 °C and upwards.
  • Biomass burners make use of heat exchangers, and at high temperatures, special materials that can withstand these will be required.
  • high temperatures are often not desirable on the consumer side, both for safety reasons and because most of the need for heating can be met with temperatures of, for example, 100 °C or lower.
  • a mineral (for example stone or ceramic) heat exchanger between the combustion process and the heat sink, which may typically be a metal pipe with circulating water and which is, for example, embedded or built-in in the mineral element.
  • the external-heat engine In order for such a plant to be a profitable investment, the external-heat engine must be at a cost level and have reliability during operation attractive to the market.
  • a typical smaller building mass (house, ag ricultural building, office, smaller industrial building and so on) representing, after all, the largest market in number, has a small electrical-power need, but few available technologies exist that can be used for this purpose.
  • An external-heat engine for this purpose will typically have to have an available electrical-power output of somewhere between 1 and 10 kW, which has turned out to be hard to obtain at a reasonable cost.
  • the invention has for its object to remedy or reduce at least one of the drawbacks of the prior art or at least provide a useful alternative to the prior art.
  • Any lubricating oil intermingled must be separated from the working fluid in the working-fluid circuit.
  • the invention seeks to solve several of these problems.
  • the problems 3 to 5 in the above list can be limited, possibly eliminated, in that a working fluid with pre-admixed lubricant may be used.
  • the admixed lubricant must be able to operate at the same temperature as those to which the working fluid is exposed.
  • Some silicone oils could be used for such a purpose, and some sil icone oils could also be used as the working fluid, which could simplify the mixing process.
  • a separate lubricating system may still exist, which is used for portions of the engines in which no particular cross-mixing is expected between the working fluid and a lubricant.
  • a bipartite crank block (that is to say, the actual crank block and an oil pan) including the crankcase, a crankshaft, con-rod, bearings, seals and also an oil sump and so on.
  • a cylinder block including cylinder liners, lubrication channels and cooling channels and so on, wherein the cylinder block, when completely assembled, will also contain pistons.
  • a bipartite cylinder-head block (that is to say, the cylinder-head block and an upper valve-gear housing) often containing a valve gear, such as camshafts, rocker arms, valves, inlet ports and exhaust ports and so on.
  • cylinder block in several cases, it is also common for the cylinder block to be combined with the "upper" part of the crank block by the two consisting mainly of one piece of cast material, which moreover may apply to the invention as well.
  • combustion engines have further components, for example for the operation of a camshaft (timing chain/belt), seals, engine starter, coolant pump, generator, air inlet, exhaust system, injector/carburettor, instruments, smaller actuators, cosmetic covers, engine control unit (ECU) and possibly a gearbox and so on.
  • ECU engine control unit
  • All engines use a working fluid (that is to say air, combustion gases, water, organic fluids and so on), and it is the temperature increase of the working fluid that drives the engine by the pressure of the working fluid increasing and being utilized to do work on a piston, for example.
  • the working fluid is in direct thermal contact with the expansion chambers (variable-volume chambers) of the engine, which, in piston engines, are mainly surrounded and thereby defined by the cylinder wall, the cylinder head, possibly the valves, and the "top side" of the piston. It is thereby also these surfaces that are subjected to the greatest heat exposure, and consequently these that will require a greatest extent of temperature control.
  • thermal i nsulation may be arranged between the cylinder block and the cylinder-head block instead, especially in cases in which it may be assumed that the heat leakage from the cylinder block towards other components, for example the crank block, is so low, for example at lower operating temperatures, that a possible heat loss will be less significant.
  • the cylinder block could be combined with the upper part of the crank block, into a single piece of material.
  • Corresponding measures can be taken for the cylinder-head block if, for example, it is assumed that the engine has overhead camshafts.
  • the cylinder head often includes both the upper part of the combustion chamber, that is to say the actual "top” of the cyli nder chamber with the valve seats and the ends of the valves, and the valve-gear mechanisms (camshaft, rocker arms and so on).
  • the valve-gear mechanisms camshaft, rocker arms and so on.
  • the cylinder-head block and the valve-gear block which has thereby been partitioned off, may also operate at different temperature levels.
  • variable-volume-chamber-/cylinder-chamber-containing engine blocks are separated thermally from the rest of the engine.
  • a thermal barrier may be a rranged between the variable-volume-chamber-containing engine blocks and the surroundings, possibly also between the variable-volume-chamber-containing engine blocks and further engine blocks, if these are exposed towards each other. Thermal barriers may be arranged between further engine blocks and the surroundings as well.
  • DE102009017279A1 refers to techniques for preventing heat flux from the work chamber of a heat engine for an azeo- tropic steam mixture, whereas the others refer to corresponding techniques for other variations of heat engines, with particular focus on internal-combustion engines.
  • the thermal barriers could be formed from different materials. In the simplest case, this may mean seals of a particularly good insulating material or combination of materials. It could also be a seal of a larger thickness than what is conventionally used, as long as it is a poor heat conductor. In other cases, the thermal barriers could be made out of one material type with poor heat-conducting properties. For example, acid-proof steel or chrome steel will be a poorer heat conductor, and thereby a better thermal barrier, than for example copper in the form of a copper seal. Insulating seals made up of several layers of different materials, as in a sandwich solution, could also be used. Some mineral materials and ceramic materials could be used as well.
  • the cylinder block itself may form a thermal barrier in itself.
  • materials of particularly poor thermal conductivity such as chrome steel, acid-proof steel et cetera.
  • a gas or possibly vacuum could also be used as a thermal barrier.
  • the gas may be air, for example.
  • This may be implemented in combination with spacer elements/inserts, so that a possible thermal connection is minimized into applying only to the spacer elements, typically in the form of a flange, a liner, an edge or a distance bolt.
  • Spacer elements/inserts may thus be made from materials of high thermal resistance, for example chrome steel or some other form of stainless steel.
  • An engine block may thus be made in such a way that only one or a few intermediate piece(s) is/are in thermal contact with a next block.
  • two or more different engine blocks may also be made out of one piece of material by them still being separated by a thermal barrier in the form of a cavity/formed channel that may hold an insulator, for example air or vacuum, there being cross-section- restricting intermediate pieces made in the formation, for example in the form of castings, wherein the intermediate pieces, because of their restricted cross section, will only conduct a limited amount of heat.
  • a thermal barrier in the form of a cavity/formed channel that may hold an insulator, for example air or vacuum, there being cross-section- restricting intermediate pieces made in the formation, for example in the form of castings, wherein the intermediate pieces, because of their restricted cross section, will only conduct a limited amount of heat.
  • a barrier could also be used in a piston, as it is shown, inter alia, in figure 4a, in which thermal conduction between upper and lower portions of the piston is restricted to an annular cross-sectional area in a transition portion between a piston head/piston dome and the other portions of the piston.
  • the radially peripheral part of the dome of the piston will function as an inter- mediate piece and will, thus, exhibit limited thermal conductivity, as a gas, vacuum/void or possibly some other type of insulator fills a cavity between the dome of the piston and the rest of the piston, as it is shown in the figure.
  • a thermal barrier may alternatively or additionally be arranged in the axial extension of the piston head, for example in the form of an applied layer of an insulating material, as it is shown in figure 4c.
  • FIGS. 2a, 2d, 2e and 3a show physical block diagrams of how thermal barriers can be arranged as it has been explained above, and in relation to common prior art as shown in figure 1, in which no thermal barriers have been arranged.
  • variable-volume-chamber-containing engine blocks will not require corresponding thermal barriers as there will be no significant heat leakage between them.
  • thermal barriers heat insulation
  • an axial extension may be made on the piston, usually in the form of a dome with a thermally insulating solution as described above, in order thereby to create a larger physical distance to the sliding surfaces of the cylinder, which would limit the heat leakage into the surfaces that require the most lubrication.
  • Such an axial extension/dome could also be used to increase the inner surface of the cylinder head, as the dome could displace a larger volume in the cylinder head. This could be particularly beneficial in cases in which it is desirable to implement an internal heat-exchanger function in the engine, and in which it is desirable, in the main, to arrange a heat exchanger in the cylinder head.
  • Such an extension will then help to move the variable-volume chamber "up" into the cylinder head, so that the portion of the variable-volume chamber that is contained/surrounded by the cylinder head is increased, which may be favourable in the case in which it is desirable to limit the exposure of heat towards the cylinder/cylinder wall.
  • the piston is made with an axial extension with insulating properties, it may be sufficient to provide a cavity in the extension, as it has also been explained above, as this will limit thermal conduction be- tween a top side and a bottom side of the piston. This cavity may be evacuated to create vacuum, which will further limit the thermal conduction.
  • a dome can also be made of an insulating material.
  • oil-sintered cylinder liners which are more or less self-lubricating, which could limit the need for lubrication.
  • valve guide of a material that exhibits low friction, for example a form of bronze alloy or its equivalent, may be arranged, and, combined with a valve stem, maybe of an oil- impregnated metal, for example steel, the need for lubrication for it could then be minimized, possibly eliminated.
  • the figures 9c and 9d show sections with examples of this, in which the valve guide functions as a tight connection and guide for a valve stem which is extending from a valve-gear block to a cylinder-head block.
  • the valve guide has a limited area of cut in the axial direction and will thereby conduct only a limited amount of heat from the cylinder-head block to the valve-gear block, and in addition, it will function as a seal between these and have a friction low enough for the sliding movement of the valve stem.
  • Various seals may also be arranged in connection with the valve guide, possibly in the form of elastomers, and a position stop may be arranged, to control the axial position relative to one of the engine blocks.
  • a sealing device could be arranged, for example in the form of a cup, which has further individual seals placed in abutment against, for example, an upper inner portion of the valve-gear block and against the valve stem.
  • FIGS. 9c and 9d further show a thermal barrier arranged between a cylinder- head block and a valve-gear block, precisely in the form of a combination of insulating inserts, possibly in the form of a metal of poor thermal conductivity, and a space, for example an air gap.
  • Figure 9d shows a valve gear as well, in the form of a camshaft in combination with a rocker arm, the rocker arm having a friction-limiting roller, and the rocker arm being supported on an adjustable rocker-arm supporting pin with a counter nut, which is, moreover, usual within other prior art.
  • a physical barrier that can limit the clearance between the crankshaft and the cylinder can be made as well. This will bring about a restriction of oil circulation towards the cylinder liner, the bottom side of the piston and the upper part of the piston rod/con- rod.
  • a physical barrier may be, for example, an extension of a thermal barrier arranged already, or it may be a separate component.
  • a cross-head solution with an associated gland could also be implemented to separate the crankcase from the cylinders, as it is usual in several piston steam-engine constructions, but this will in turn complicate the design somewhat.
  • Corresponding measures can also be used at the valve stems, at which, among other things, leakage of lubricant from the valve-gear block to the cylinder chambers could arise as well. This could also limit a possible leakage of working fluid in the opposite direction.
  • Use may also be made of other types of lubricants that can withstand somewhat higher temperatures.
  • the exposure of a small portion of lubricating oil to materials having somewhat higher temperatures could be allowed, as long as the amount is small enough for the lubricating properties of the total amount of lubricating oil not to deteriorate substantially, as the small amount could be mixed with the remaining amount over time, by it returning to a common oil reservoir, for example an oil sump placed below the crankshaft, which is very usual.
  • FIG. 9a, 9b, 9c and 9d show this principle, which is relatively common in combustion engines, in which a rocker arm is fitted with rollers in one or more transition portions and in which the rollers may be based on needle bearings, for example, or have needle-bearing support. Needle bearings and possibly ball bearings may also be used for the big-end bearing at the crankshaft or at the gudgeon pin of the piston.
  • the crank support may also be of the needle or ball type, possibly other corresponding roller solutions.
  • a lubricant for example in the form of an alternative additive, mixed directly into the working fluid, as in a two-stroke petrol engine, could also be used, which could somewhat simplify the problems to be addressed. In that case, it will be required that the lubricant/additive will be able to withstand the prevailing temperatures of the working fluid.
  • a closable bypass may be made, forming a connection between two variable-volume chambers, the variable-volume chambers possibly exhibiting substantially different total volumes.
  • the differences in total volumes may be implemented, for example, by different stroke lengths being provided for the associated pistons, whereas, in other respects, the cylinder bores may be identical. In other cases, the cylinder bores may be different, or use may be made of more complex cylinder/piston geometries.
  • FIG. 7 and 8 An example of a compound engine is shown in figures 7 and 8. In the figures, the bypass is shown as a channel connecting the two cylinder chambers, a bypass valve regulating the fluid flow therein.
  • Such a compound engine will then be defined by a high- pressure cylinder and a low-pressure cylinder, possibly also by medium-pressure cylinders, the high-pressure cylinder having the smallest stroke volume then.
  • the volume ratio between a high-pressure cylinder and a low-pressure cylinder in a two-stage compound engine will typically be in the range from 1 : 1.5 to 1 : 7.
  • Several different piston-engine solutions could, with simplicity, give these volume ratios. It turns out that a volume ratio in the range from 1 : 1.5 to 1 : 2.5 could be particularly beneficial, especially for compound engines using working fluids with lower boiling points than water.
  • one or more internal heat exchangers with thermal connections to the cylinder chambers can be arranged, in order thereby to perform an alternative thermodynamic cycle having heat supply to the working fluid during expansion.
  • Such heat exchangers could also help to limit losses associated with cylinder condensation, that is to say losses in consequence of the working fluid condensing on the inner surfaces of the variable-volume chambers. This turns out to be one of the most important problems to be addressed in different solutions for two- phase heat engines, that is to say heat engines using a condensable working fluid.
  • heat-exchanger channels may have been formed for heat to be exchanged from a thermofluid to the working fluid through a heat-exchanger wall, which may possibly be part of the inner walls of the cylinder or the cylinder head.
  • a possible heat-exchanger wall could also be formed from a separate piece of material.
  • Heat-exchanger channels could be formed, for example, in the cylinder head, in the cylinder, possibly in both. Further, various forms of heat-exchanger-enhancing formations may be arranged, either as part of the cylinder or the cylinder head, or possibly as separate elements with good thermal connection to the heat-exchanger channels, so that a high heat flux to the working fluid may be achieved.
  • the heat-exchanger-enhancing formations could be in the form of either surface-improving formations, such as elements of unevenness or different patterns, and/or surface-increasing formations such as heat-exchanger fins.
  • Figure 4 shows an example of how at least one radial heat-exchanger fin may be formed in the part of the variable-volume chamber which is defined by the cylinder head.
  • working-fluid inlet openings may, with advantage, be arranged in the axial region of the cylinder head which includes the heat-exchanger-enhancing formations, as it is illustrated in figure 4c.
  • the cylinder head consists of a material of good thermal conductivity, and in which, possibly, the cylinder consists of a material of lower thermal conductivity, it could be beneficial for the greater part of the portion of heat flux that is to be supplied to the working fluid internally to be supplied here.
  • an injector/inlet valve may be arranged with fluid communication into a variable-volume chamber via a working-fluid inlet with the associated working-fluid inlet opening.
  • the working-fluid inlet opening may also be arranged in such a way that a relatively tangential working-fluid inflow into the cylinder chamber can be achieved, possibly other controlled directions.
  • the working-fluid inlet opening may then, in a preferred manner, generally be arranged in the cylinder head as it is shown in figure 8 as well.
  • the working-fluid inlet opening may also have the function of a nozzle.
  • the cylinder head may further be formed with turbulence-encouraging formations or elements, and it may be formed with formations regulating the flow direction, such as pegs, wings or fins. In a specific form, it may be provided with helical fins, so that working fluid that is injected relatively tangentially will be guided up towards the u pper part of the cylinder head, for example. In a case in which, principally, an internal heat exchanger is to be placed only in the part of the variable-volume chamber defined by the cylinder head, this may help to increase the convection across the heat exchanger, which could help to further enhance the heat transmission.
  • the patent document US 5839270 discloses a heat engine which utilizes tangential injection into an antechamber utilized as a heat-exchanger chamber (see for example figures 10 and 11), in which the tangential injection into the chamber helps to enhance heat exchange.
  • This document also refers further to a publication written by Z. Guo arid V. K. Dhir, entitled “Effects of Injection Induced Swirl Flow on Single and Two-Phase Heat Transfer” (AS ME HTDF Vol. 81, pp 77-84, 1987) describing, inter alia, positive effects on the heat transmission by injecting a fluid tangentially in order to achieve swirl flow/cyclonic flow inside a heat exchanger.
  • the article deals with heat exchange for a fluid in both the single-phase state and the two-phase state. This principle is utilized with advantage in the present invention.
  • a generator connected to the movement converter/crankshaft of the external-heat engine could be used to produce electrical power.
  • a generator in the form of a stator connected to one of the blocks of the external-heat engine, for example the movement- converter/crank block, and a rotor connected to the movement converter/crankshaft may be arranged.
  • the rotor may, with advantage, be supported freely suspended with the crankshaft as the only supporting element, as the need to use further roller bea rings or equivalents, which, in turn, would require accurate alignment during fitting and/or installation to limit wear in long-term use, may then be eliminated.
  • the invention also relates to a method which can be practised by means of the external-heat engine according to the invention, among other things.
  • the method mainly comprises a thermodynamic process for the operation of the external-heat engine and handling leakage of working fluid and lubricant appropriately.
  • the external-heat engine could primarily be operated by means of a two-phase (alternation between the gaseous and liquid phases) thermodynamic process such as a Rankine cycle, a modified Rankine cycle or possibly an alternative two-phase cycle. Secondarily, other thermodynamic cycles could be used, including single-phase cycles (gas phase) such as the Brayton cycle. If the external-heat engine is operated by means of a two-phase cycle, it will typically constitute part of an external-heat engine system with surrounding units as described in further detail below, enabling a process consisting of, for example, the following steps:
  • the working fluid is injected into at least one variable-volume chamber through at least one closable working-fluid inlet and an associated working-fluid inlet opening; d) the working fluid expands in the at least one variable-volume chamber;
  • the working fluid is ejected from the at least one variable-volume chamber through at least one working-fluid outlet;
  • step d) further heat could be supplied to the working fluid, for example by means of at least one internal heat exchanger which is in thermal contact with the variable-volume chamber.
  • a typical heat-transmission fluid for example a thermo-oil, water or a gas, alternatively a combination thereof, could transmit heat between an external heat reservoir and the heat exchangers of the engine.
  • the heat exchangers could then transfer heat between the heat-transmission fluid and the working fluid, and preferably from the heat-transmission fluid to the working fluid in the case of an external-heat engine.
  • a separator such as an oil separator may be arranged .
  • oil separator By means of this, it may be ensured that oil leaking into the working-fluid circuit is separated and returned to the oil reservoir in a satisfactory way via a lubricant-return port formed with connection to the oil reservoir, for example an oil sump. If necessary, in an exa mple like that, a pump could be used to return the lubricating oil to the oil reservoir.
  • working fluid could leak in the opposite direction from the cylinder chambers (blow-by) and accumulate in the crankcase contained in the crank block.
  • working fluid could leak in a direction from the cylinder chambers and accumulate in the valve-gear housing.
  • a typical working fluid that has leaked into these areas could be in gas form, it could be removed and returned to a working-fluid reservoir by means of a distillation principle, either by it being condensed in a main cooler/condenser or by it being condensed in a separate leakage-fluid cooler, and then being returned to the working-fluid reservoir by means of a pump, for example.
  • the latter may be formed with working-fluid return ports in appropriate places.
  • a typical surrounding system may include a working-fluid pump, a heater (maybe with one or more of a preheater, an evaporator, and alternatively an overheater), an injector (which may possibly be integrated in the engine itself), an oil pump, an oil separator, a leakage-oil return pump, a cooler (possibly in the form of a condenser), a leakage-fluid cooler, and a leakage-fluid pump, and a working-fluid reservoir.
  • a working-fluid pump possibly with one or more of a preheater, an evaporator, and alternatively an overheater
  • an injector which may possibly be integrated in the engine itself
  • an oil pump an oil separator
  • a leakage-oil return pump possibly in the form of a condenser
  • a cooler possibly in the form of a condenser
  • a leakage-fluid cooler and a leakage-fluid pump
  • the cooler/condenser could necessarily be left out in its entirety, as the working fluid in the form of air could be returned to the atmosphere, in which it is then cooled instead.
  • further system components may be necessary, such as several sensors, for example temperature, pressure, level, position and flow sensors, an ECU (Engine Control Unit), a generator and a power-electronics unit (possibly including a frequency converter, adapted for a consumer).
  • the system may be equipped with communication devices for the communication of both control and measurement signals and electrical power/energy with an external system.
  • the commun ication device may be a simple electrical-power cable with connection to an electrical- power consumer.
  • the invention relates to the use of the external-heat engine and/or the method in accordance with the invention for operating a combined heat and power plant.
  • external-heat engines operating at low temperature levels will always exhibit relatively low efficiency, it could be very beneficial precisely to utilize the residual heat from the heat-engine process for the heating of, for example, water, air and various rooms in a building mass, a vessel or a plant located more or less outdoors, the external-heat engine then constituting part of a combined heat and power plant (CHP system), and then possibly a small-scale CHP plant (micro- CHP).
  • CHP system combined heat and power plant
  • micro- CHP small-scale CHP plant
  • a CHP plant system may, in the main, be built up around a heat source, a cold source (heat sink), an external-heat engine system and a multi-energy output, for example.
  • the external-heat engine system may consist of an external-heat engine and other heat-engine system devices, for example a pump, an ECU, a power- electronics unit and various instruments etc.
  • the multi-energy output may include at least one device for communicating mechanical or electrical energy with an external system, and at least one device for communicating heat to the external system.
  • the heat source may provide heat by burning wood chips, pellets, fire wood, oil or gas, heat recovery from ventilation air and other waste-heat sources, solar heat, process water and so on.
  • the heat source may thereby provide the necessary heat both to operate the external-heat engine system and deliver heat to heat consumers in a building system, for example a hot-water system and a building heating system.
  • All or parts of the residual/waste heat from the external-heat engine may also be used for this purpose, and in such a case, heat consumers in the building system could constitute the function of the cold source/heat sink, wherein this may then possibly be replaced by the heat consumers.
  • the external-heat engine converts a portion of the heat energy from the heat source into mechanical energy according to its efficiency. It may then supply mechanical energy, or most relevant electrical energy, to energy consumers associated with the building system, by the generator converting the mechanical energy into electrical energy.
  • the heat consumers may be of various kinds, for example a water-heating device, a room-heating device or a thermal cooling system like an absorption cooler or an adsorption cooler, which often uses a certain amount of heat to create a somewhat smaller amount of cold.
  • the CHP plant system may be placed in or in the vicinity of the building, possibly a vessel, or any other device that has a need for different forms of energy, but then most naturally, and in most cases, on a smaller scale.
  • the CHP plant system may also be arranged for use by several buildings, possibly vessels, at the same time.
  • the invention relates more specifically to an external-heat engine which uses a working fluid, the external-heat engine including at least the following engine blocks:
  • At least one movement-converter block provide with at least one movement converter
  • At least one valve-gear block provided with at least one valve-gear device
  • variable-volume-chamber-containing engine blocks are the following variable-volume-chamber-containing engine blocks:
  • At least one cylinder block provided with at least one cylinder, the at least one cylinder having, arranged therein, a piston arranged for oscillating, translatory movement in the cylinder, the piston being connected to the at least one movement converter via a connecting device;
  • At least one cylinder-head block provided with at least one cylinder head; the at least one cylinder together with the at least one cylinder head forming a variable-volume chamber, the piston arranged in the at least one cylinder forming a first axial boundary of the variable-volume chamber, and the at least one cylinder head forming a second, opposite, axial boundary of the variable-volume chamber, characterized by
  • At least one thermal barrier being arranged between at least one of the variable-volume-chamber-containing engine blocks and at least one of the other engine blocks.
  • thermal barrier arranged between at least one engine block and the surroundings.
  • the engine blocks of the external-heat engine may be made up in the following order of positions, with a normal direction from the bottom to the top:
  • the external-heat engine may be connected to at least one unit taken from the group consisting of a pump, heater, injector, condenser and working-fluid reservoir in order thereby to be able to perform a thermodynamic cycle.
  • the external-heat engine may be arranged to perform a Rankine cycle by the heater including a preheater and an evaporator, alternatively also an overheater.
  • the working fluid may have a lower normal boiling point than water, in order thereby to be able to perform an ORC cycle (Organic Rankine Cycle).
  • ORC cycle Organic Rankine Cycle
  • the external-heat engine may be arranged to perform an alternative thermodynamic cycle by at least one of the at least one cylinder block and the at least one cylinder- head block including at least one internal heat exchanger.
  • At least one working-fluid return port may have been arranged, which is connected in a fluid-communicating manner to an upstream portion of a leakage-fluid cooler or a condenser.
  • the leakage-fluid cooler may be connected, downstream and in a fluid-communicating manner, to a leakage-fluid pump, and the leakage-fluid pump may be connected, downstream and in a fluid-communicating manner, to a working-fluid reservoir.
  • the at least one variable-volume chamber may be provided with a working-fluid outlet which is connected in a fluid-communicating manner to at least one separator.
  • the separator may be provided with a lubricant- return path which is connected in a fluid-communicating manner to a lubricant reservoir, and a working-fluid outlet which is connected in a fluid-communicating manner to the condenser.
  • the external-heat engine may be arranged to perform a regulated thermodynamic cycle by an engine control unit being arranged to receive instrument signals from one or more of at least one pressure sensor, at least one fluid-flow sensor, at least one temperature sensor, at least one position sensor and at least one level sensor, and, via regulation algorithms, give control signals to and thereby, directly or indirectly, control one or more of at least one pump actuator and the injector.
  • an engine control unit being arranged to receive instrument signals from one or more of at least one pressure sensor, at least one fluid-flow sensor, at least one temperature sensor, at least one position sensor and at least one level sensor, and, via regulation algorithms, give control signals to and thereby, directly or indirectly, control one or more of at least one pump actuator and the injector.
  • a generator may be arranged, which is mechanically synchronized with the movement converter.
  • the engine control unit may be arranged to receive regulation-feedback signals and give control signals to a power-electronics unit in order thereby to control the power- electronics unit, the power-electronics unit being electrically connected to and communicating electrical power with the generator.
  • the external-heat engine may be arranged to communicate electrical power with an external system via a communication device which connects the power-electronics unit to the external system.
  • the power-electronics unit may at least include a frequency converter (AC/DC/AC converter) arranged to communicate electrical power compatible with what is required by the external system, or in the form of a sinusoidal electrical voltage at a given frequency.
  • a frequency converter AC/DC/AC converter
  • the engine control unit may be arranged to communicate status and/or control signals with the external system via a communication device connecting the engine control unit to the external system.
  • a piston head may be arranged, which is arranged to enhance thermal insulation between the at least one variable-volume chamber and the at least one piston.
  • One or more of the pistons may be made from a carbon material (carbon piston) in order thereby to limit the need for lubrication of the cylinder liner.
  • the at least one cylinder and/or the at least one valve may, at least in part, be formed from a lubricant-impregnated material, such as an oil-impregnated, sintered metal.
  • the external-heat engine may be arranged to function as a compound engine by at least one first variable-volume chamber being connected in a fluid-communicating manner to a second variable-volume chamber through a working-fluid bypass, the working-fluid bypass being closable by means of a bypass valve located in the fluid- flow path of the working-fluid bypass, the second variable-volume chamber exhibiting a total volume substantially different from the total volume of the at least one first variable-volume chamber.
  • At least one internal heat exchanger may be in thermal contact with at least one variable-volume chamber.
  • the invention relates more specifically to a thermodynamic process for the operation of an external-heat engine as described above, which uses a working fluid and a lubricant, characterized by the process including the following steps:
  • the working fluid is pumped under high pressure through a heater
  • the working fluid is injected into at least one variable-volume chamber through at least one closable working-fluid inlet and an associated working-fluid inlet opening; d) the working fluid expands in the at least one variable-volume chamber;
  • the working fluid is ejected from the at least one variable-volume chamber through at least one working-fluid outlet;
  • thermodynamic process may include the further step of:
  • thermodynamic process may include the further step of:
  • thermodynamic process may include the further step of:
  • step cc) after step e) and before step f), passing the working fluid through a separator in order thereby to remove an amount of lubricant that has mixed with the working fluid.
  • thermodynamic process may include the further step of returning the amount of lubricant that is removed from the working fluid by means of the separator to a lubricant reservoir.
  • Step d) may further include supplying heat to the working fluid.
  • the invention relates more specifically to the use of an external-heat engine and/or a thermodynamic process as described above for the operation of a CHP plant.
  • Electrical energy provided by a generator may be consumed by at least one electrical-energy consumer.
  • a portion of heat from the CHP plant may be used by at least one heat consumer.
  • a portion of heat from the CHP plant may be used for cooling by at least one heat consumer being a thermal cooling device.
  • Figure la shows a physical block diagram of a heat engine in the form of a prior- art piston engine, with a movement-converter block (crank block), cylinder block, cylinder-head block (including a valve gear), valve- synchronization block, and also a crankshaft, cylinder, piston and ca mshaft;
  • crank block movement-converter block
  • cylinder block cylinder block
  • cylinder-head block including a valve gear
  • valve- synchronization block and also a crankshaft, cylinder, piston and ca mshaft
  • Figure lb shows the cylinder-head block as shown in figure la, but where it has been divided into two portions;
  • Figure lc shows the movement-converter block (crank block) as shown in figure la, but where it has been divided into two portions; shows a physical block diagram of the heat engine as shown in figure 1, but in which the cylinder block and the upper part of the movement- converter block have been combined into one piece of material; shows a physical block diagram of a heat engine according to the invention, in which the heat engine in the form of a single-cylinder piston engine has engine blocks like the prior art as shown in figure la, but in which, instead, the cylinder-head block has been divided into a separate, simplified cylinder-head block and a separate valve-gear block, and in which thermal barriers have been arranged between some of the engine blocks, and between some engine blocks and the surroundings; shows the valve-gear block as shown in figure 2a, but where it has been divided into two portions; shows the movement-converter block as shown in figure 2a, but where it has been divided into two portions; shows a physical block diagram of the heat engine as shown in figure 2a, but in which a thermal barrier has
  • Figure 9c shows, on a larger scale, a partially cut-away principle drawing of a valve solution, in which the valve is extending through a valve guide spanning both a cylinder-head block and a valve-gear block, there being thermal barriers arranged between the cylinder-head block and the valve-gear block in the form of insulating spacers and spaces/air gaps;
  • Figure 9d shows a principle drawing of the valve solution as shown in figure 9c, but in which a roller-relieved rocker arm is arranged as a transmission between the camshaft and the valve;
  • FIG 10 shows a principle drawing of a heat exchanger (heater) which includes a preheater, an evaporator/boiler and an overheater;
  • FIG 11 shows schematically a CH P system installed in or in association with a building, in this example a house partly cut through;
  • Figure 12 shows schematically a CH P system installed in or in association with a vessel, in this case a boat;
  • Figure 13 shows schematically a principle drawing of an external-heat engine system used in the operation of a CH P system, with basic components of the CH P system and its possible connections to a consumer group of consumers which can be defined as any unit using energy produced by the CH P system.
  • the symbol "m” denotes an amount of working fluid circulating in the engine.
  • Q V i and Q V2 represent the heat that is being supplied to the working fluid from, respectively, an external heat exchanger and an internal heat exchanger that are in thermal contact with a working-fluid path.
  • the working-fluid paths include all cavities and passages in which the working-fluid is naturally expected to be present and/or flow in/through during the operation of a heat-engine system 2.
  • Qvi may also comprise the sum of QF V , Q F D and Q 0 H as they are shown in figure 10, as an internal heat exchanger and/or an external heat exchanger may include one or more of, respectively, a preheater, an evaporator and an overheater, alternatively also a recuperator (not shown).
  • Q K represents the heat that is removed from the working fluid by means of an internal heat exchanger 300, 301 (see figure 8) or, in a preferred manner, an external heat exchanger, for example a condenser 800, which is in ther- mal contact with a working-fluid path.
  • Q s represents the heat that is removed from a leaked amount of working fluid, by means of a leakage-fluid cooler 91 which is in thermal contact with a leakage-fluid return circuit, as the leakage-fluid is to be separated, for example from the lubricating oil, and then returned to a working-fluid circuit, for example back to a working-fluid reservoir 90.
  • an external-heat engine a method and use in accordance with the invention, reference is made to elements in one or more of at least one external- heat engine 1, at least one external-heat engine system 2 and at least one CHP system 3000, as they are shown in figures 4c, 8, 9a, 9c, 9d, 10 or 13, the device elements being identified by reference numerals that are shown in one or more of the figures 2a to 13.
  • the reference numerals indicate the corresponding device elements that are found in the external-heat engine 1 and the external-heat engine system 2 according to the invention as they are described below.
  • the external-heat engine 1 includes, in the main, the movement-converter/crankshaft block 5, the cylinder block 10, the cylinder-head block 11 and the valve-gear block 7, the movement-converter/crankshaft block 5 being divided into a first, lower movement-converter-block portion 5a, also termed an oil sump/oil pan, and a second, upper movement-converter-block portion 5b, and the valve-gear block 7 being divided into a first, lower valve-gear-block portion 7a and a second, upper valve-gear-block portion 7b, also termed an upper valve-gear housing.
  • the cylinder-head block 11 may consist of a first cylinder-head block 11a and a second cylinder-head block l ib, as they may be formed with different working-fluid-path solutions, it then possibly being natural to separate them into two separate units.
  • the first cylinder-head block 11a may be formed with a working-fluid inlet 400
  • the second cylinder-head block l ib may be formed with a working-fluid outlet 410 different in character from the working-fluid inlet 400
  • the first and second cylinder-head blocks together may include a working-fluid bypass 450 providing a fluid-communicating connection between the two.
  • the movement-converter/crankshaft block 5 contains a movement-converter 50, or more specifically a crankshaft.
  • the valve-gear block 7 contains a valve-gear device 70, also termed a camshaft, with various movement convertions, such as a rocker arm 71 with one or more rollers 79, also termed rocker-arm rollers, as they are shown in figures 9a, 9b, and 9d.
  • the rocker arm 71 is shown with a fixed support 72, this forming the centre of the rocking motion of the rocker arm 71.
  • the rocker-arm support 72 is shown here as an axially adjustable rocker-arm-supporting pin 72a with a counter nut 72b arranged in a rocker-arm-supporting base 73, for example part of the valve-gear block. In this way, clearances between the camshaft 70, the rocker arm 71 and a valve stem 710a, or a bypass valve 710, may be adjusted according to common, known methods for valve-operated piston engines.
  • the bypass valve 710 is guided through a valve guide 790 (see figure 9d) which, in a first, lower axial portion, is in contact with the cylinder-head block 11 and which, in a second, upper axial portion, is in contact with the valve-gear block 7.
  • the valve guide 790 has been fitted by a lower axial portion having been pressed down into the cylinder-head block 11 where a position lock 790b locks it axially.
  • valve guide 790 has been inserted into and through a lower portion of the valve-gear block 7, a space 190" forming a thermal barrier 190 between the cylinder-head block 11 and the valve-gear block 7, and a valve-guide seal 790a preventing fluid leakages into/from the valve-gear block 7.
  • the cylinder-head block 11 and the valve-gear block 7 are mechanically connected in a thermally insulating ma nner by spacer elements/liners 190"' forming thermal barriers 190 between them, the spacer elements/liners 190"' exhibiting, at the same time, sufficient rigidity and strength to keep the relative positions between the cylinder-head block 11 and the valve-gear block 7 fixedly locked .
  • a valve-spring mount 791 with a sealing function encloses the valve stem 710a and ensures further sealing of the valve-gear block 7 by it being provided with a valve-spring-mount seal 791a placed in abutment against the valve stem 710a and a valve-spring-mount seal 791b placed in abutment against the valve-gear block 7.
  • valve-spring mount 791 holds a valve spring 795 in a lower portion, whereas a valve-spring disc 792 functions as an abutment between the valve spring 795 and the valve stem 710a as the valve-spring disc 792 is mechanically locked relative to the valve stem 710a and the valve spring 795 thereby exerts a push force on the bypass valve 710 in a direction towards the closed valve position, as it is often implemented in various known engine solutions.
  • the camshaft 70 is synchronized with the crankshaft 50 via a valve-synchronizing device 70a (see figure 8), typically in the form of a timing chain or a timing belt, which is driven by and drives valve-synchronizing-device gears 70b, more specifically a timing- chain gear or timing-belt driving gear, mounted on the crankshaft 50 and camshaft 70, respectively.
  • the timing chain/timing belt 70a may be part of and accommodated by a valve-synchronization block 7c, more specifically a timing-chain case 7c.
  • valve-synchronizing device 70a in association with the valve-synchronizing device 70a, one or more of, for example, a chain-/belt-tightening device (not shown) and a chain/belt guide (not shown) in the form of a rotating unit, such as a chain or belt gear, could be arranged according to what is usual in different known valve-synchronizing devices.
  • a chain-/belt-tightening device not shown
  • a chain/belt guide in the form of a rotating unit, such as a chain or belt gear
  • the crankshaft 50 may be connected to a flywheel 59 for rotational motion stabilization, see for example figure 4a .
  • An electric generator 1200 (see figure 4c) and more particularly a generator rotor 1203 may also constitute the function of the flywheel 59 and thereby replace it.
  • the electric generator 1200 may produce electrical power by being connected to the crankshaft 50.
  • the generator consists, in the main, of a generator housing 1201, a generator stator 1202, a generator rotor 1203 and one or more electromagnetic elements 1204, for example permanent magnets, which are attached to the rotor 1203.
  • the generator rotor 1203 is mechanically synchronized with the crankshaft 50 in a manner known per se, by it being mounted, freely suspended, on an axial end portion of the crankshaft 50, as it is shown in figure 4c.
  • the external-heat engine 1 is provided with thermal barriers 190, 190' (see for exa mple figures 2d, 2e, 3a, 4a-4c), more specifically thermal insulation 190 between the crankshaft block 5 and the cylinder block 10, thermal insulation 190 between the cylinder-head block(s) 11, 11a, l ib and the valve-gear block 7, and thermal insulation 190' between the cylinder block 10 and the surroundings, or between the cylinder- head block(s) 11, 11a, l ib and the surroundings.
  • thermal barriers 190, 190' see for exa mple figures 2d, 2e, 3a, 4a-4c
  • thermal insulation 190' may also be arranged between the cylinder block 10 and the cylinder-head block(s) 11, 11a, l ib as it is shown in figure 4b, or the cylinder block 10 may be made of a metal of poor conductivity and thereby, in itself, constitute thermal insulation 190' between an upper portion of the cylinder block 10 and the crankshaft block 5, as it is shown in figure 4c. In such cases, the insulation 190 between the crankshaft block 5 and the cylinder block 10 could be left out.
  • the thermal barrier between the cylinder-head block 11 and the valve-gear block 7 is indicated in figure 9d as air gaps/cavities 190" and spacer elements/intermediate pieces 190"' made from an insulating material.
  • the external-heat engine 1 is further provided with two, respectively first and second, cylinders 100, 101 and associated cylinder heads 110 and 111, respectively, each accommodating a first or second piston 200, 201, respectively, arranged for oscillating, translatory displacement within the respective cylinders 100, 101.
  • Each of the pistons 200, 201 is provided with a piston head 200a and 201a, respectively, filling a substa ntial part of the cylinder head 110 and 111, respectively, when the respective piston 200 and 201, respectively, is in its top dead-centre position.
  • the cylinders 100, 101, the cylinder heads 110, 111 and the pistons 200, 201 form a first variable- volume chamber 150 and a second variable-volume chamber 151, respectively, as the pistons 200, 201 arranged in the cylinders 100, 101 form a first, lower axial boundary of the variable-volume chambers 150, 151 and the cylinder heads form a second, upper axial boundary of the variable-volume chambers 150, 151.
  • the translatory displacement of the pistons 200, 201 inside the cylinders 100, 101 and in the cylinder heads 110, 111, respectively, will then bring about a volume change in the variable- volume chambers 150, 151.
  • the pistons 200, 201 are further connected to the crankshaft 50 via first and second crank rods 60 and 61, respectively, for power/energy transmission.
  • the cylinders 100, 101 form fluid-tight sliding surfaces against the pistons 200, 201, and, for this purpose, the pistons 200, 201 may possibly be fitted with piston seals, such as piston rings (not indicated).
  • the first variable-volume chamber 150 is connected to the second variable-volume chamber 151 by the working-fluid bypass 450 being closable and regulated by means of a bypass valve 750 placed in the fluid flow path of the working-fluid bypass 450.
  • the external-heat engine 1 is thereby arranged as a compound expander, as the second cylinder chamber 151 exhibits a considerably larger total volume than the first cylinder chamber 150, by the lengths of stroke of the pistons 200, 201 being considerably different because the corresponding piston-rod attachment radii of the crankshaft 50 are different.
  • the lengths of the piston rods 60, 61 will be correspondingly different, in accordance with the difference in the lengths of stroke of the pistons 200, 201, so that the top dead-centre positions of the pistons will, in the main, be identical.
  • the external-heat engine 1 uses a working fluid 9, for example pentane 9, to perform one or more thermodynamic processes in a thermodynamic cycle, or to perform a purely mechanical process such as carrying out work on an external load by means of a fluid flow from a hydraulic pressure reservoir.
  • a working fluid 9 for example pentane 9
  • pentane 9 to perform one or more thermodynamic processes in a thermodynamic cycle, or to perform a purely mechanical process such as carrying out work on an external load by means of a fluid flow from a hydraulic pressure reservoir.
  • working fluids that can be used are water, air and other gases, further alkanes such as propane, butane, hexane and heptane or molecular variations (isomers) thereof (for example iso- or neohexane and so on), toluene, diethyl ether, and other ethers, silicone oils (for example siloxanes) or further cooling mediums such as rl23, rl34a and r245fa and so on.
  • alkanes such as propane, butane, hexane and heptane or molecular variations (isomers) thereof (for example iso- or neohexane and so on)
  • toluene diethyl ether
  • silicone oils for example siloxanes
  • further cooling mediums such as rl23, rl34a and r245fa and so on.
  • a pump 500 pumps the working fluid 9 from low into high pressure by means of a regulated pump actuator 501, more specifically a pump motor 501.
  • the working fluid is then carried into an external heater 600 via a first working-fluid line 900a which is also provided with a fluid-flow sensor 1501 and a pressure sensor 1502, the fluid-flow sensor 1501 and the pressure sensor 1502 communicating instrument signals 1001 to an ECU (engine control unit) 1000 which, in turn, based on the measurement levels of the different instruments 1501, 1502, regulates the pump motor 501 via control signals 1002.
  • ECU engine control unit
  • the working fluid 9 is supplied with heat from the heater 600, consisting of and supplying heat through one or more of a preheater 610, an evaporator 620, and an over- heater 630 (see figure 10), alternatively also through a recuperator (not shown), the working fluid flowing on via a second working-fluid line 900b provided with a temperature sensor 1060, leading into an ejector 700.
  • the ECU 1000 controls the injector 700 which determines the working-fluid flow into the first variable-volume chamber 150, the injector 700 being connected in a downstream portion in a fluid-communicating manner to the working- fluid inlet 400 with the associated working-fluid inlet opening 401, typically in the form of a nozzle.
  • a given amount of working fluid 9 will then, for a given period, flow into the first cylinder chamber 150, it being expanded here and, at the same time, having extra heat Qv2 supplied to it by the internal heat exchangers 300, 301 which are in thermal communication with the first cylinder chamber 150.
  • the heat exchangers 300, 301 have heat-exchanger surfaces that are defined by a portion of the inner surface of a first cylinder head 110 and a portion of the inner surface of a first cylinder 100, respectively.
  • the expansion is carried out by the first piston 200 moving mainly from the top dead centre (TDC) to the bottom dead centre (BDC), creating a volume change with a positive sign, as in most piston expanders, as, for example, in 4-stroke com- bustion engines.
  • the first cylinder head 110 and possibly its heat exchanger 300 may be provided with fluid-flow-controlling formations (not shown), guiding the working-fluid flow within the first cylinder chamber 150 in a particular direction.
  • the heat exchanger 300 may also be provided with heat-exchanger-enhancing formations, for example surface- increasing elements in the form of heat-exchanger fins 121, as it is shown in figure 4c.
  • the nozzle 401 may then be arranged in such a way that the working fluid will enter a portion 120 of the cylinder head that includes heat-exchanger fins.
  • the nozzle 401 may be positioned in such a way that the fluid flow out of it will be nearly tangential to the inner surface of the first cylinder head 110, possibly also of the first cylinder 100, the creation of a circular or cyclonic fluid flow then being enabled, which will help to encourage convection and thereby also increase the heat-transfer figure of the internal heat-exchanging process which will then take place.
  • the bypass valve 750 opens to fluid flow through the working-fluid bypass 450 into the second cylinder chamber 151, the working-fluid being expanded in a second expansion process by being moved from the first 150 into the second cylinder chamber 151 in a compound-expansion process.
  • the working fluid is then carried from the working-fluid outlet 410 into a working-fluid inlet 30c of a lubricant/oil separator 30 via a third working-fluid line 900c, which is also provided with a pressure sensor 1110.
  • the lubricant separator 30 provides for the separation of any lubricant 36 intermingled with the working fluid 9.
  • the oil 36 separated, if any, is returned to an oil reservoir 35, which may be an oil sump located in the crank block 5, an oil-return pump 32 controlled by an oil-return pump actuator/motor 33 pumping the oil 36 from an oil-return outlet 30b of the oil separator 30 into the oil reservoir 35 via an oil-return port 37.
  • the working fluid 9 is carried further from the oil separator 30 to a condenser 800, by a working-fluid outlet 30a of the oil separator 30 being connected in a fluid- communicating manner to the condenser 800 via a fourth working-fluid line 900d.
  • the working fluid 9 is cooled, and possibly condensed in the condenser 800, and the cooled-down working fluid 9 is finally returned to the working-fluid reservoir 90 via a fifth working-fluid line 900e.
  • a sixth working-fluid line 900f connects the working-fluid reservoir 90 to the pump 500, so that the working fluid 9 may be communicated from the working-fluid reservoir 90 back to the pump 500 when a new duty cycle is to be performed.
  • net work may be output on the crankshaft 50 of the external-heat engine 1.
  • working-fluid return ports 99 have therefore been formed in different parts of the external-heat engine 1, wherein a leaked amount of working fluid 9 may be carried back to the working-fluid reservoir 90, either via the leakage- fluid cooler 91 or via the condenser 800 through first and second leakage-fluid lines 990a and 990b or through the first leakage-fluid line 990a and the fourth working-fluid line 900d.
  • a check valve may possibly prevent backflow at varying pressure differences.
  • a leaked amount of working fluid is carried from the working-fluid return ports 99, through the first leakage-fluid line 990a, and the fourth working-fluid line 900d to the condenser 800, by a second end portion 990a" of the first leakage-fluid line 990a being in fluid communication with the fourth working-fluid line 900d.
  • leakage-fluid lines 990a, 990b, working-fluid lines 900d, 900e, the condenser 800, the leakage-fluid cooler 91 and the leakage-fluid pump 92 may be used in order to return a leaked amount of working fluid 9 to the working-fluid reservoir 90 in a satisfactory way.
  • Lubrication may generally take place as in common combustion engines, by a conventional oil pump (not shown) circulating lubricating oil 36 from the oil sump 35, and distributing it via lubrication lines/channels (not shown) to the various places in the external-heat engine 1 where it is needed, for example to the camshaft 70, the cylinders 100, 101 and the crankshaft 50, and their possibly associated rollers, liners, bearings and so on. Excess oil may then be returned in a conventional manner via lubricating-oil return lines/channels (not shown). There are several solutions for distributing and returning lubricating oil to/from the oil sump 35. Nor further importance will be attached to this, as it may be considered to be obvious to a skilled person.
  • the external-heat engine 1 could be simplified somewhat by lubricant 36 being added directly to the working fluid 9, then being allowed to circulate together with this through the external-heat engine 1.
  • lubricant 36 possibly a lubricant additive, which may resist the strains, in terms of temperature, to which it will be subjected.
  • a generator 1200 is connected to the crankshaft 50, possibly physically after a flywheel 59, and delivers electrical power P E i_ via a power-electronics unit 1300 which is connected to an electrical-power communication device 2001, for example a cable.
  • the power-electronics unit 1300 may be a connection point, for ex- ample consisting of electrical terminals, but in a more common case, it will i nclude for example a frequency converter (AC/DC/ AC converter), an inverter (DC/AC converter) or, in a simpler case, a rectifier (AC/DC converter) .
  • the generator 1200 may contain electrical filters, a control unit for regulating power output, possibly power i nput, which may be used, for example, when starting the external -heat engine if the generator 1200 is also adapted for operation as a motor. It may also contain, possibly be connected to, an energy storage (not shown), for example a battery, which may be used during start-up, for example. It may further give instrument signals 1001 to, and receive control signals 1002 from, the ECU 1000, for example, the ECU 1000, on a superior level, being able to regulate the power communication between the generator 1200 and the external system 2000 in one or both directions. The magnitude of the power PEL supplied may be based on the estimated power output available from the external- heat engine 1 and the desired power delivery to a consumer 3110 in the external system 2000.
  • an amount of residual heat Q K may be distributed to a heat consumer 3120 in the external system 2000.
  • the heat consumer 3120 may be, for exa mple, a device for heating water, a system for heating buildings or a so-called thermal cooling system, for example an absorption cooler or an adsorption cooler.
  • the ECU 1000 monitors and regulates the operation of the external -heat engine 1 including one or more of the external heat-engine devices, for example the pump 500, the injector 700 and the power-electronics unit 1300, as mentioned ea rlier.
  • the ECU 1000 receives and processes measurements from different places in the engine 1 or the external-heat-engine system 2 by means of one or more instrument signals 1001.
  • the ECU 1000 is operated by software containing, inter alia, regulation algorithms, so that the external-heat engine 1 including one or more of the other devices may be controlled on the basis of set-point values.
  • the set-point values may include, for example, user settings for the desired power output P EL , the desired temperature for heat output and so on .
  • the regulation algorithms implemented in the ECU 1000 will then provide for the external-heat engine 1 to convert and deliver thermal energy Q A v and QAK and electrical energy in the form of the converted electrical power P E i_ in the best possible way, by the ECU 1000 controlling the external-heat engine 1 on the basis of, inter alia, the heat Q V i and Q V 2 available, and the temperature at which it is delivered, and also the cooling capacity available in the form of how much residual heat Q K can be carried away from the system, and the cooling temperature available.
  • the ECU 1000 will typically have a communication interface, in the form of a commu- nication device 2002, with the external system 2000, as the ECU 1000 may then be controlled and monitored by one or more external regulating units 3200 connected to the external system 2000, by communication signals K being exchanged.
  • the communication device 2002 may be, for example, a radio transceiver, a data-network-based communication unit, an analogue communication device, possibly in the form of a simple cable, or a combination thereof.
  • the external-heat engine 1 is further exemplified in the figures 4a to 7, and alternative embodiment details are discussed below.
  • a single-cylinder external-heat engine 1 is shown in a single-expansion embodiment, in which a cylinder chamber 150 has a working-fluid inlet 400 with an associated working-fluid inlet opening 401 and a working-fluid outlet 410, so that the single-cylinder external-heat engine 1 is arranged to perform a single-expansion process.
  • Figure 4b shows a corresponding configuration, but with a thermal ba rrier 190 between the cylinder block 10 and the cylinder-head block 11 instead of between the crankshaft block 5 and the cylinder block 10, as it is shown in figure 4a.
  • Figure 4c shows a further configuration of the external-heat engine 1, but with internal heat exchangers 300, 301, a valve guide 790, an integrated generator 1200 and a heat- exchanger-enhancing formation 121 (a heat-exchanger fin) in a cylinder chamber 150, in which a thermal barrier between the cylinder-head block and the valve-gear block consists of air gaps, that is to say cavities, 190" and spacer elements 190"' made from an insulating material, and in which a thermal barrier between the cylinder-head block 11 and the movement-converter block 5 is formed by the cylinder block 10 having been formed from a material of poor conductivity, and in which there are thermal ba rriers 190' between the cylinder block 10 and the cylinder-head block 11, respectively, and the surroundings.
  • a thermal barrier between the cylinder-head block and the valve-gear block consists of air gaps, that is to say cavities, 190" and spacer elements 190"' made from an insulating material
  • Figure 5 shows a two-cylinder embodiment of the external-heat engine 1 in a single- expansion embodiment, in which two independent cylinder chambers 150, 151 each have a working-fluid inlet 400a, 400b with associated working-fluid inlet openings 401a and 401b, respectively, and respective working-fluid outlets 410a, 410b, so that the two-cylinder external-heat engine 1 is arranged to carry out single-expansion processes in the two cylinder chambers 150, 151.
  • Figure 6 shows a two-cylinder embodiment of the external-heat engine 1 in a single- expansion embodiment, similar to that shown in figure 5, but in which, in addition, internal heat exchangers 300, 301 have been arranged, in order to supply heat to a working fluid 9 during expansion inside the cylinder chambers 150, 151.
  • Figure 7 principally shows the external-heat engine 1 in a compound embodiment as it has been described above.
  • the invention may also perform corresponding and complementary compression processes.
  • the working-fluid inlet 400 mentioned earlier will function as a working-fluid outlet, and corresponding functional changes will apply to the working-fluid outlet 410, the injector/inlet valve 700 and the outlet valve 710.
  • FIG 13 In an application of the external-heat engine 1 and the method (the thermodynamic process) in accordance with the invention, there is a combined heat and power plant 3000, hereinafter also called a CHP system, i ncluding an external-heat-engine system 2, a heat source 3031, a cold source 3033 and a multi-energy output 3300.
  • the external-heat-engine system 2 includes, in turn, the external-heat engine 1 and the other heat-engine-system devices, such as the pump 500 and the power-electronics unit 1300 as they have been described above and shown in figure 8.
  • the heat source 3031 supplies heat Q V i and Q V 2 to the external-heat-engine system 2, and the residual heat Q K from the external-heat-engine system 2 is removed by means of the cold source 3033.
  • the multi-energy output 3300 supplies energy to a consumer group 3100 in the external system 2000.
  • the consumer group 3100 may include one or more electrical-energy consumers 3110 and one or more heat consumers 3121, wherein the heat consumers may be a water-heating device, a room-heating device or a thermal cooling system such as an absorption cooler or an adsorption cooler.
  • the CHP system 3000 is shown schematically.
  • the CHP plant system 3000 is connected via the multi-energy output 3300 to the energy-consumer group 3100.
  • the heat source 3031 is thermally connected to the heat-engine system 2 which, in turn, is thermally connected to the cold source 3033.
  • the heat source 3031 delivers an amount of heat Q V i and Q V 2 to the heat-engine system 2. From a heat- draw-off point 3310 arranged in the thermal connection between the heat source 3031 and the heat-engine system 2, high-grade heat energy Q A v can be delivered via a heat-source-heat output 3391 to one or more heat consumers 3120.
  • the heat-engine system 2 is connected and supplies electrical energy P E i_ to the electrical-energy consumer 3110.
  • the heat-engine system 2 may, in a corresponding manner, deliver mechanical energy to a mechanical-energy consumer (not shown) in the energy-consumer group 3100.
  • the electrical-energy consumer 3110 or heat-energy consumer 3120 may also be units with connections to, but placed externally to, the external system 2000, for example by the external system 2000 being connected to forwarding distribution units (not shown), such as an electrical distribution unit (not shown) which may feed surplus current onto a larger electrical distribution network (not shown).
  • residual-heat energy Q A K may be delivered to one or more heat consumers 3120 via a residual-heat output 3393.
  • An energy consumer 31 10, 3120 may also have the functions of both a heat-energy consumer 3120 and an electrical-energy consumer 3110.
  • An example of this is an absorption cooling system, which needs electrical energy for pumps, which, in turn, drive a fluid circulation, and thermal energy/heat energy as energy supply for the actual absorption cooling process.
  • the heat-source-heat output 3391 , the electrical-energy output 3392 and the residual- heat-energy output 3393 together form the multi-energy output 3300.
  • the multi- energy output 3300 forms an appropriate interface between the CH P plant system 3000 and a distribution network (not shown) in the external system 2000, for example for the distribution of electrical current for heating and lighting and heat energy for room heating and so on.
  • the CH P plant system 3000 is placed in a building 3001 (see figure 11) or a vessel 3002 (see figure 12) , possibly some other plant (not shown), in which there is a need for energy supply Q A v, PEL, Q A K to one or more energy consumers 3110, 3120.
  • the heat source 3031 provides high-grade heat energy Q V i and Q V2 for the heat-engine system 2, for example by burning wood chips, pellets, fire wood, oil or gas, heat recovery from ventilation air and other waste-heat sources, process water and so on. Whenever needed, a portion of the heat energy Q V i and Q V2 may be used by drawing from the heat-draw-off point 3310 for use in one or more energy consumer(s) 3120 that need(s) high-grade heat energy in order to function efficiently.
  • a portion of the residual heat Q K which is normally transferred from the external-heat-engine system 2 to the cold source 3033, may be distributed via the residual-heat output 3393 to the consumer group 3100 in which the heat consumers 3120 that can use low-grade heat energy make use of this residual heat in a practical way, for heating, for example. If the need for heat energy is great enough in the heat consumers 3120, all the waste heat Q K from the external-heat-engine system 2 may be distributed to the consumer group 3100, and consequently, the cold source 3033 will not have to receive any of it.
  • the function of the independent cold source 3033 could then be constituted by the consumer group 3100, so that this will also function as a cold source 3033.
  • the CHP plant system 3000 is arranged in a basement of the building 3001.
  • An alternative positioning of the CHP plant system is indicated by the reference numeral 3000', here indicated outside the building 3001.
  • the HCP plant system 3000 is placed internally in the vessel 3002.
  • An alternative positioning of the CHP plant system 3000' is indicated as well, here a rranged in the immediate vicinity of the storage yard of the vessel 3002.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Engine Equipment That Uses Special Cycles (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)

Abstract

Moteur thermique externe (1) utilisant un fluide actif (9) dans lequel au moins une chambre à volume variable (150, 151) est composée d'au moins une unité (10, 11, 11a, 11b, 100, 101, 110, 111), et dans lequel pour au moins une des unités formant au moins une chambre à volume variable (10, 11, 11a, 11b, 100, 101, 110, 111), au moins une barrière thermique (190, 190', 190", 190''') est agencée, empêchant un flux de chaleur d'au moins une des unités formant des chambres à volume variable (10, 11, 11a, 11b, 100, 101, 110, 111) de passer dans au moins une unité périphérique (5, 7, 10, 11, 11a, 11b, 100, 101, 110, 111) et/ou l'environnement. Le processus thermodynamique pour le fonctionnement d'un moteur thermique externe (1) est également décrit. Enfin, l'usage du moteur thermique externe (1) et/ou du processus thermodynamique pour le fonctionnement d'une centrale de cogénération de chaleur et d'électricité (3000) est décrit.
PCT/NO2013/050013 2012-01-20 2013-01-17 Moteur thermique externe et procédé d'exploitation d'un moteur thermique externe WO2013109152A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NO20120063A NO334747B1 (no) 2012-01-20 2012-01-20 Eksternvarmemaskin, framgangsmåte ved drift av eksternvarmemaskin, en termodynamisk prosess for drift av en eksternvarmemaskin, samt anvendelse av en eksternvarmemaskin og/eller en termodynamisk prosess ved drift av et kraftvarmeverk.
NO20120063 2012-01-20

Publications (1)

Publication Number Publication Date
WO2013109152A1 true WO2013109152A1 (fr) 2013-07-25

Family

ID=48799500

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NO2013/050013 WO2013109152A1 (fr) 2012-01-20 2013-01-17 Moteur thermique externe et procédé d'exploitation d'un moteur thermique externe

Country Status (2)

Country Link
NO (1) NO334747B1 (fr)
WO (1) WO2013109152A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015057077A1 (fr) * 2013-10-17 2015-04-23 Viking Heat Engines As Dispositif perfectionné de moteur à chaleur externe
WO2016124923A1 (fr) * 2015-02-03 2016-08-11 Fluid Energy Solutions International Limited Unité d'étanchéité et moteur fluidique

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4024801A (en) * 1970-09-23 1977-05-24 Perry David Hudson Extended insulated hot head piston with extended insulated hot cylinder walls
US4212162A (en) * 1977-02-21 1980-07-15 Kabushiki Kaisha Toyota Chuo Kenkyusho Constant combustion engine
EP0049941A1 (fr) * 1980-07-09 1982-04-21 Neil Douglas Shelton Moyens pour prévenir l'écoulement de chaleur d'un fluide actif vers les surfaces des composants des machines à piston thermodynamiques
US5063881A (en) * 1989-07-17 1991-11-12 Isuzu Motors Limited Ceramic engine
US5562079A (en) * 1995-02-23 1996-10-08 The United States Of America As Represented By The Administrator Of The U.S. Environmental Protection Agency Low-temperature, near-adiabatic engine
WO1999047803A1 (fr) * 1998-03-13 1999-09-23 Dennis Gutteridge Moteur de rankine integre
US6170441B1 (en) * 1998-06-26 2001-01-09 Quantum Energy Technologies Engine system employing an unsymmetrical cycle
WO2011154622A1 (fr) * 2010-06-11 2011-12-15 Bernard Macarez Culasse echangeur

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4024801A (en) * 1970-09-23 1977-05-24 Perry David Hudson Extended insulated hot head piston with extended insulated hot cylinder walls
US4212162A (en) * 1977-02-21 1980-07-15 Kabushiki Kaisha Toyota Chuo Kenkyusho Constant combustion engine
EP0049941A1 (fr) * 1980-07-09 1982-04-21 Neil Douglas Shelton Moyens pour prévenir l'écoulement de chaleur d'un fluide actif vers les surfaces des composants des machines à piston thermodynamiques
US5063881A (en) * 1989-07-17 1991-11-12 Isuzu Motors Limited Ceramic engine
US5562079A (en) * 1995-02-23 1996-10-08 The United States Of America As Represented By The Administrator Of The U.S. Environmental Protection Agency Low-temperature, near-adiabatic engine
WO1999047803A1 (fr) * 1998-03-13 1999-09-23 Dennis Gutteridge Moteur de rankine integre
US6170441B1 (en) * 1998-06-26 2001-01-09 Quantum Energy Technologies Engine system employing an unsymmetrical cycle
WO2011154622A1 (fr) * 2010-06-11 2011-12-15 Bernard Macarez Culasse echangeur

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015057077A1 (fr) * 2013-10-17 2015-04-23 Viking Heat Engines As Dispositif perfectionné de moteur à chaleur externe
CN105637185A (zh) * 2013-10-17 2016-06-01 维金热引擎有限公司 改进的外燃热机设备
US9874175B2 (en) 2013-10-17 2018-01-23 Viking Heat Engines As External heat engine device
CN105637185B (zh) * 2013-10-17 2018-07-03 维金热引擎有限公司 改进的外燃热机设备
WO2016124923A1 (fr) * 2015-02-03 2016-08-11 Fluid Energy Solutions International Limited Unité d'étanchéité et moteur fluidique
US20180016952A1 (en) * 2015-02-03 2018-01-18 Fluid Energy Solutions International Limited Sealing unit and fluid engine

Also Published As

Publication number Publication date
NO334747B1 (no) 2014-05-19
NO20120063A1 (no) 2013-07-22

Similar Documents

Publication Publication Date Title
US8590302B2 (en) Thermodynamic cycle and heat engine
CA2577585C (fr) Moteur a recuperation de chaleur
CN105863874B (zh) 斯特林发动机
US10337452B2 (en) Energy recovery system
US6827104B2 (en) Seal and valve systems and methods for use in expanders and compressors of energy conversion systems
RU2673954C2 (ru) Поршневой мотор-компрессор с интегрированным двигателем стирлинга
AU2015212952B2 (en) A compressor train with a stirling engine
JP4848058B1 (ja) スターリングエンジン
WO2013109152A1 (fr) Moteur thermique externe et procédé d'exploitation d'un moteur thermique externe
JP5525371B2 (ja) 外燃式クローズドサイクル熱機関
US7784280B2 (en) Engine reversing and timing control mechanism in a heat regenerative engine
US5390496A (en) Stirling engine with annular cam
WO2008011036A2 (fr) Bandage de moteur avec échange de chaleur air/air
KR101024121B1 (ko) 저온수로 구동되는 엔진 및 발전시스템
WO2008011038A2 (fr) Soupapes d'espace nuisible dans un moteur thermique à régénération
US3877232A (en) Piston engine utilizing a liquefiable gaseous fluid
WO2013149315A1 (fr) Moteur à piston servant à convertir un gaz sous pression en énergie mécanique
WO2007003926A1 (fr) Ensemble vilebrequin
Da Silva The development, construction and testing of a piston-expander for small-scale solar-thermal power plants.
US20230243261A1 (en) External combustion rotary engine
GB2546423A (en) Energy generation systems
WO2022214945A1 (fr) Système et procédé pour générer de l'énergie mécanique à l'aide de dioxyde de carbone supercritique
CN111022183A (zh) 热电联产系统

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13738169

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13738169

Country of ref document: EP

Kind code of ref document: A1