US20130008165A1 - Rankine cycle system - Google Patents
Rankine cycle system Download PDFInfo
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- US20130008165A1 US20130008165A1 US13/636,246 US201013636246A US2013008165A1 US 20130008165 A1 US20130008165 A1 US 20130008165A1 US 201013636246 A US201013636246 A US 201013636246A US 2013008165 A1 US2013008165 A1 US 2013008165A1
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- steam
- discharge path
- expander
- liquid refrigerant
- outlet
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- 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
- F01K25/10—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 the vapours being cold, e.g. ammonia, carbon dioxide, ether
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- 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
- F01K23/00—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids
- F01K23/02—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled
- F01K23/06—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle
- F01K23/065—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle the combustion taking place in an internal combustion piston engine, e.g. a diesel engine
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- 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
- F01K9/00—Plants characterised by condensers arranged or modified to co-operate with the engines
Definitions
- the present invention relates to a Rankine cycle system.
- An exemplary Rankine cycle that recovers exhaust heat generated due to operation of an internal-combustion engine.
- An exemplary Rankine cycle makes a water-cooled cooling system of an engine have a sealed structure to carry out the ebullient cooling, drives an expander such as a steam turbine by refrigerant vaporized by exhaust heat of the engine, i.e. steam, and recovers exhaust heat by converting thermal energy included in the steam into electrical energy, for example.
- Patent Document 1 is one example that improves the above-described Rankine cycle system.
- a temperature of an expander is generally low when the internal-combustion engine is cold. If steam is supplied to the expander in a low temperature state, the steam is condensed in the expander, and goes back to liquid refrigerant. The liquid refrigerant produced in the expander is retained in the expander, becomes a resistance against the drive of the expander, and may cause deterioration or damage of the expander.
- a Rankine cycle system is implemented to a vehicle, it is necessary to solve the problem of deterioration or damage of the expander described above because the expander frequently becomes in a cold state.
- control valve that controls inflow of steam into the expander while the internal-combustion engine is warmed up, in order to suppress the deterioration and damage of the expander.
- the above-described control needs an actuator that actuates the control valve, and a temperature sensor to set a control timing or a development of a logic to estimate the temperature, and thus increases cost.
- a problem to be solved by a Rankine cycle system disclosed in the present specification is to suppress deterioration and damage of an expander caused by production of liquid refrigerant in the expander such as a steam turbine.
- a Rankine cycle system disclosed in the present specification is characterized by including: a superheater, an expander that is driven by steam, which is vaporized refrigerant supplied from the superheater, to recover energy, and includes a first outlet discharging steam and a second outlet discharging liquid refrigerant produced by condensation of the steam in the expander; a first discharge path that is connected to the first outlet and discharges the steam from the expander; a condenser into which the steam is introduced through the first discharge path, and that condenses the steam into liquid refrigerant, a condensed water tank that reserves the liquid refrigerant produced in the condenser; and a second discharge path that connects the second outlet to the condensed water tank and discharges the liquid refrigerant from the expander.
- the expander has the second outlet, and thus is able to discharge the liquid refrigerant produced by condensation in the expander when the expander is in a cold state. If the liquid refrigerant can be discharged from the expander, it is possible to reduce drive load of the expander. As a result, the deterioration and damage of the expander can be suppressed.
- the second outlet is provided to a downside portion of the expander. It is for discharging the liquid refrigerant efficiently regardless of an inner shape of the expander and the like. Generally, the liquid refrigerant can be discharged by providing the second outlet to the downside portion of the expander.
- a liquid level in the condensed water tank satisfies a following relation: ⁇ h> ⁇ Pto/ ⁇ g, when a difference between the liquid level and a lowest liquid level in the second discharge path is expressed by ⁇ h, a pressure loss when the steam flows into the condenser from the expander through the first discharge path is expressed by ⁇ Pto, a density of the liquid refrigerant is expressed by ⁇ , and a gravitational acceleration is expressed by g.
- a connected position of the second discharge path to the condensed water tank may be located higher than the lowest liquid level in the second discharge path.
- the second discharge path is formed of a U-tube
- the second discharge path is a U-shaped portion of the U-tube, and ⁇ h can be set large. If ⁇ h is set large, it is possible to prevent the steam from flowing through the second outlet effectively.
- a diameter of the second outlet may be smaller than a diameter of the first outlet. It is possible to prevent the steam from flowing through the second outlet effectively by setting a relation between the diameter of the first outlet and the diameter of the second outlet so as to satisfy the above-described relation. In addition, if the diameter of the first outlet becomes large, the pressure loss ⁇ Pto can be reduced, and this is effective for preventing the steam from flowing through the second outlet.
- a flow passage area of the second discharge path is smaller than a flow passage area of the first discharge path.
- the relation expressed by the above equation can be achieved by making an inside diameter of a pipe forming the second discharge path smaller than an inside diameter of a pipe forming the first discharge path. It is possible to prevent the steam from flowing through the second outlet by making a relation between the flow passage area of the second discharge path and the flow passage area of the first discharge path satisfy the above-described relation. In addition, if the flow passage area of the first discharge path becomes large, the pressure loss ⁇ Pto can be reduced, and this is effective for preventing the steam from flowing through the second outlet.
- FIG. 1 is a schematic configuration diagram of a Rankine cycle system of an embodiment
- FIG. 2 is an explanatory diagram enlarging a part A in FIG. 1 ;
- FIG. 3 is an explanatory diagram illustrating another shape of a second discharge path.
- FIG. 1 is a schematic configuration diagram of the Rankine cycle system 100 .
- FIG. 2 is an explanatory diagram enlarging a part A in FIG. 1 .
- the Rankine cycle system 100 has an engine 1 that is cooled by boiling of refrigerant therein.
- the engine 1 is an example of an internal-combustion engine corresponding to a steam generator.
- the engine 1 includes a cylinder block 1 a and a cylinder head 1 b .
- a water jacket is formed in the cylinder block 1 a and the cylinder head 1 b , and the engine is cooled by boiling of the refrigerant in the water jacket.
- the engine 1 produces steam at this time.
- the engine 1 further includes an exhaust pipe 2 .
- One end of a steam pathway 3 is connected to the cylinder head 1 b of the engine 1 .
- a gas-liquid separator 4 is arranged in the steam pathway 3 .
- the gas-liquid separator 4 separates the refrigerant, which is in a gas-liquid coexistence state and flows into the gas-liquid separator 4 from the engine 1 side, into a gas phase (steam) and a liquid phase (liquid refrigerant).
- One end of a refrigerant circulating path 5 is connected to a bottom end portion of the gas-liquid separator 4 .
- the other end of the refrigerant circulating path 5 is connected to the cylinder block 1 a .
- a first water pump 6 that pumps the liquid refrigerant into the engine 1 .
- the first water pump 6 is a so-called mechanical pump, and uses a crankshaft included in the engine 1 as a drive source.
- the first water pump 6 circulates the liquid refrigerant between the engine 1 and the gas-liquid separator 4 .
- a superheater 8 is arranged in the steam pathway 3 .
- the superheater 8 includes a vaporizing portion 8 a at a lower side, and a superheating portion 8 b at an upper side.
- the exhaust pipe 2 is led to the superheater 8 .
- Exhaust gas generated in the engine 1 flows through the exhaust pipe 2 .
- the exhaust pipe 2 passes through the superheater 8 so that the exhaust gas passes through the superheating portion 8 b and the vaporizing portion 8 a in this order.
- One end of a liquid refrigerant pathway 7 is connected to the vaporizing portion 8 a .
- the exhaust gas exchanges heat with the steam passing through the gas-liquid separator 4 .
- the other end of the liquid refrigerant pathway 7 is connected to the bottom end portion of the gas-liquid separator 4 .
- An opening/closing valve 7 a is provided to the liquid refrigerant pathway 7 .
- An opened/closed state of the opening/closing valve 7 a determines the supply of the liquid refrigerant from the gas-liquid separator 4 to the vaporizing portion 8 a .
- the liquid refrigerant supplied to the vaporizing portion 8 a is vaporized by heat of the exhaust gas that has superheated the steam at the superheating portion 8 b . This increases a steam generation amount, improves the degree of superheating of the steam, and improves recovery efficiency of the exhaust heat.
- a steam discharge pipe 3 a is provided to an upper end portion of the superheating portion 8 b .
- a nozzle 9 is provided to a tip end portion of the steam discharge pipe 3 a.
- An expander 10 is arranged at a downstream side of the superheater 8 .
- the expander 10 is driven by vaporized refrigerant, i.e. steam, supplied from the superheater 8 , and recovers energy.
- the expander 10 is a steam turbine including a chassis 10 a and a turbine blade 10 b located in the chassis 10 a .
- the nozzle 9 is mounted to the chassis 10 a so that the steam supplied through the steam pathway 3 is injected toward the turbine blade 10 b .
- the turbine blade 10 b is rotary driven by the steam supplied through the steam pathway 3 .
- the rotative force of the turbine blade 10 b assists the rotation of the crankshaft included in the engine 1 , and drives a power generator. This recovers the exhaust heat.
- the chassis 10 a of the expander 10 is provided with a first outlet 10 a 1 that discharges the steam, and a second outlet 10 a 2 that discharges the liquid refrigerant produced by condensation of the steam in the chassis 10 a .
- the second outlet 10 a 2 is provided to a downside portion of the chassis 10 a of the expander 10 so as to discharge the liquid refrigerant in the chassis 10 a of the expander 10 .
- a diameter D 2 of the second outlet 10 a 2 is smaller than a diameter D 1 of the first outlet 10 a 1 . That is to say, a relation of D 2 ⁇ D 1 is established.
- first discharge path 11 One end of a first discharge path 11 is connected to the first outlet 10 a 1 .
- the other end of the first discharge path 11 is connected to a condenser 12 .
- the first discharge path 11 discharges the steam from the expander 10 , and introduces the discharged steam into the condenser 12 .
- the condenser 12 condenses the steam by cooling the steam, and produces the liquid refrigerant.
- the condenser 12 receives blast by a fan 13 and can cool and condense the steam efficiently.
- a condensed water tank 14 Arranged under the condenser 12 is a condensed water tank 14 that reserves the liquid refrigerant produced in the condenser 12 .
- One end of a second discharge path 15 is connected to the second outlet 10 a 2 .
- the other end of the second discharge path 15 is connected to the condensed water tank 14 .
- the above-described second discharge path 15 discharges the liquid refrigerant from the expander 10 to the condensed water tank 14 .
- the liquid refrigerant that has been cooled in the condenser 12 is reserved in the condensed water tank 14 .
- the liquid refrigerant condensed in the expander 10 is mixed with the liquid refrigerant cooled in the condenser 12 and its temperature is decreased by being discharged to the condensed water tank 14 .
- a flow passage area S 2 of the second discharge path 15 is smaller than a flow passage area S 1 of the first discharge path 11 . That is to say, a relation of S 2 ⁇ S 1 is established.
- a refrigerant recovery passage 16 that re-circulates the liquid refrigerant, which is temporarily reserved in the condensed water tank 14 , to the engine 1 side.
- the refrigerant recovery passage 16 is connected to the upstream side of the first water pump 6 in the refrigerant circulating path 5 .
- a second water pump 17 is arranged in the refrigerant recovery passage 16 .
- the second water pump 17 is an electric vane pump.
- the liquid refrigerant in the condensed water tank 14 is supplied to the refrigerant circulating path 5 .
- a unidirectional valve 18 that prevents reverse flow of the refrigerant is provided downstream of the second water pump 17 .
- the Rankine cycle system 100 includes a passage where the refrigerant is circulated.
- the relation of D 2 ⁇ D 1 is established between the diameter D 1 of the first outlet 10 a 1 included in the Rankine cycle system 100 and the diameter D 2 of the second outlet 10 a 2 as described previously.
- the relation of S 2 ⁇ S 1 is established between the flow passage area S 1 of the first discharge path 11 included in the Rankine cycle system 100 and the flow passage area S 2 of the second discharge path 15 . Maintaining the above relations is effective for preventing the steam from passing through the second outlet 10 a 2 .
- it is desirable that the steam supplied into the expander 10 is discharged from the first outlet 10 a 1 as much as possible.
- the steam which is vaporized refrigerant not condensed, is discharged from the second outlet 10 a 2 , the steam passes through the second discharge path 15 and the condensed water tank 14 , and flows into the condenser 12 . That is to say, the steam flows from a direction different from a designed inflow direction into the condenser 12 . If the steam flows into the condenser 12 from the direction different from the designed direction as described above, the function of the condenser 12 is impaired. That is to say, the condenser 12 cools and condenses the steam by heat exchange before the steam which has been introduced from the upper side thereof reaches the condensed water tank 14 , and produces the liquid refrigerant.
- the function of the condenser 12 is impaired. Moreover, the temperature of the liquid refrigerant in the condensed water tank 14 rises. The liquid refrigerant in the condensed water tank 14 is supplied to the engine 1 again, and used for cooling the engine 1 . Thus, it is required to keep the temperature of the liquid refrigerant in the condensed water tank 14 as low as possible.
- the Rankine cycle system 100 satisfies a relation expressed by a following equation (1) in order to prevent the steam from being discharged from the second outlet 10 a 2 .
- ⁇ h difference between a liquid level in the condensed water tank 14 and a lowest liquid level in the second discharge path 15
- ⁇ Pto pressure loss when the steam flows in the condenser 12 from the expander 10 through the first discharge path 11
- ⁇ density of the liquid refrigerant g: gravitational acceleration
- ⁇ h in the present embodiment is equal to ⁇ h 1 as illustrated in FIG. 1 and FIG. 2 .
- ⁇ Pto in the present embodiment is a pressure loss within a range indicated by B in FIG. 1 and FIG. 2 .
- the second discharge path 15 may be replaced with a second discharge path 151 illustrated in FIG. 3 in order to set ⁇ h large.
- a connected position P 1 of the second discharge path 151 to the condensed water tank 14 is located higher than a lowest liquid level 151 a in the second discharge path 151 .
- the lowest liquid level 151 a is lowered by making the second discharge path 151 have a U-shape. This secures ⁇ h 2 .
- ⁇ h 2 is larger than ⁇ h 1 when the second discharge path 15 is used. As a result, ⁇ h 2 easily satisfies the condition of the equation (1).
Abstract
A Rankine cycle system includes: a superheater, an expander including a first outlet discharging steam and a second outlet discharging liquid refrigerant produced therein; a first discharge path discharging the steam from the expander; a condenser condensing the steam introduced through the first discharge path into liquid refrigerant, a condensed water tank reserving the liquid refrigerant produced in the condenser; and a second discharge path discharging the liquid refrigerant from the expander to the condensed water tank, wherein a liquid level in the condensed water tank satisfies a following relation: Δh>ΔPto/ρg, when Δh means a height difference between the liquid level and a lowest liquid level in the second discharge path, ΔPto means a pressure loss when the steam flows into the condenser from the expander through the first discharge path, ρ means a density of the liquid refrigerant, and g means a gravitational acceleration.
Description
- The present invention relates to a Rankine cycle system.
- There has been conventionally known a Rankine cycle that recovers exhaust heat generated due to operation of an internal-combustion engine. An exemplary Rankine cycle makes a water-cooled cooling system of an engine have a sealed structure to carry out the ebullient cooling, drives an expander such as a steam turbine by refrigerant vaporized by exhaust heat of the engine, i.e. steam, and recovers exhaust heat by converting thermal energy included in the steam into electrical energy, for example.
Patent Document 1 is one example that improves the above-described Rankine cycle system. -
- [Patent Document 1] Japanese Patent Application Publication No. 2009-103060
- However, a following inconvenience may occur at a time of cold start of an internal-combustion engine by adopting an approach of
Patent Document 1, for example. A temperature of an expander is generally low when the internal-combustion engine is cold. If steam is supplied to the expander in a low temperature state, the steam is condensed in the expander, and goes back to liquid refrigerant. The liquid refrigerant produced in the expander is retained in the expander, becomes a resistance against the drive of the expander, and may cause deterioration or damage of the expander. When a Rankine cycle system is implemented to a vehicle, it is necessary to solve the problem of deterioration or damage of the expander described above because the expander frequently becomes in a cold state. It is considered to provide a control valve that controls inflow of steam into the expander while the internal-combustion engine is warmed up, in order to suppress the deterioration and damage of the expander. However, the above-described control needs an actuator that actuates the control valve, and a temperature sensor to set a control timing or a development of a logic to estimate the temperature, and thus increases cost. - Therefore, a problem to be solved by a Rankine cycle system disclosed in the present specification is to suppress deterioration and damage of an expander caused by production of liquid refrigerant in the expander such as a steam turbine.
- To solve the above-described problem, a Rankine cycle system disclosed in the present specification is characterized by including: a superheater, an expander that is driven by steam, which is vaporized refrigerant supplied from the superheater, to recover energy, and includes a first outlet discharging steam and a second outlet discharging liquid refrigerant produced by condensation of the steam in the expander; a first discharge path that is connected to the first outlet and discharges the steam from the expander; a condenser into which the steam is introduced through the first discharge path, and that condenses the steam into liquid refrigerant, a condensed water tank that reserves the liquid refrigerant produced in the condenser; and a second discharge path that connects the second outlet to the condensed water tank and discharges the liquid refrigerant from the expander.
- The expander has the second outlet, and thus is able to discharge the liquid refrigerant produced by condensation in the expander when the expander is in a cold state. If the liquid refrigerant can be discharged from the expander, it is possible to reduce drive load of the expander. As a result, the deterioration and damage of the expander can be suppressed.
- It is desirable that the second outlet is provided to a downside portion of the expander. It is for discharging the liquid refrigerant efficiently regardless of an inner shape of the expander and the like. Generally, the liquid refrigerant can be discharged by providing the second outlet to the downside portion of the expander.
- It is desirable that a liquid level in the condensed water tank satisfies a following relation: Δh>ΔPto/ρg, when a difference between the liquid level and a lowest liquid level in the second discharge path is expressed by Δh, a pressure loss when the steam flows into the condenser from the expander through the first discharge path is expressed by ΔPto, a density of the liquid refrigerant is expressed by ρ, and a gravitational acceleration is expressed by g.
- If the liquid level in the condensed water tank is maintained so as to satisfy the above-described relation, it is possible to prevent the steam from flowing through the second outlet.
- A connected position of the second discharge path to the condensed water tank may be located higher than the lowest liquid level in the second discharge path. For example, when the second discharge path is formed of a U-tube, the second discharge path is a U-shaped portion of the U-tube, and Δh can be set large. If Δh is set large, it is possible to prevent the steam from flowing through the second outlet effectively.
- Furthermore, a diameter of the second outlet may be smaller than a diameter of the first outlet. It is possible to prevent the steam from flowing through the second outlet effectively by setting a relation between the diameter of the first outlet and the diameter of the second outlet so as to satisfy the above-described relation. In addition, if the diameter of the first outlet becomes large, the pressure loss ΔPto can be reduced, and this is effective for preventing the steam from flowing through the second outlet.
- In addition, it is desirable that a flow passage area of the second discharge path is smaller than a flow passage area of the first discharge path. For example, the relation expressed by the above equation can be achieved by making an inside diameter of a pipe forming the second discharge path smaller than an inside diameter of a pipe forming the first discharge path. It is possible to prevent the steam from flowing through the second outlet by making a relation between the flow passage area of the second discharge path and the flow passage area of the first discharge path satisfy the above-described relation. In addition, if the flow passage area of the first discharge path becomes large, the pressure loss ΔPto can be reduced, and this is effective for preventing the steam from flowing through the second outlet.
- According to the Rankine cycle system disclosed in the present specification, it is possible to suppress deterioration and damage of an expander caused by production of liquid refrigerant in the expander.
-
FIG. 1 is a schematic configuration diagram of a Rankine cycle system of an embodiment; -
FIG. 2 is an explanatory diagram enlarging a part A inFIG. 1 ; and -
FIG. 3 is an explanatory diagram illustrating another shape of a second discharge path. - Hereinafter, a description will be given of modes for carrying out the present invention in detail with reference to drawings.
- A description will be given of an outline structure of a Rankine
cycle system 100 with reference toFIG. 1 andFIG. 2 .FIG. 1 is a schematic configuration diagram of theRankine cycle system 100.FIG. 2 is an explanatory diagram enlarging a part A inFIG. 1 . The Rankinecycle system 100 has anengine 1 that is cooled by boiling of refrigerant therein. Theengine 1 is an example of an internal-combustion engine corresponding to a steam generator. Theengine 1 includes a cylinder block 1 a and acylinder head 1 b. A water jacket is formed in the cylinder block 1 a and thecylinder head 1 b, and the engine is cooled by boiling of the refrigerant in the water jacket. Theengine 1 produces steam at this time. Theengine 1 further includes anexhaust pipe 2. One end of asteam pathway 3 is connected to thecylinder head 1 b of theengine 1. - A gas-
liquid separator 4 is arranged in thesteam pathway 3. The gas-liquid separator 4 separates the refrigerant, which is in a gas-liquid coexistence state and flows into the gas-liquid separator 4 from theengine 1 side, into a gas phase (steam) and a liquid phase (liquid refrigerant). One end of a refrigerant circulating path 5 is connected to a bottom end portion of the gas-liquid separator 4. The other end of the refrigerant circulating path 5 is connected to the cylinder block 1 a. In addition, in the refrigerant circulating path 5, arranged is a first water pump 6 that pumps the liquid refrigerant into theengine 1. The first water pump 6 is a so-called mechanical pump, and uses a crankshaft included in theengine 1 as a drive source. The first water pump 6 circulates the liquid refrigerant between theengine 1 and the gas-liquid separator 4. - A
superheater 8 is arranged in thesteam pathway 3. Thesuperheater 8 includes a vaporizing portion 8 a at a lower side, and asuperheating portion 8 b at an upper side. Theexhaust pipe 2 is led to thesuperheater 8. Exhaust gas generated in theengine 1 flows through theexhaust pipe 2. Theexhaust pipe 2 passes through thesuperheater 8 so that the exhaust gas passes through the superheatingportion 8 b and the vaporizing portion 8 a in this order. One end of a liquidrefrigerant pathway 7 is connected to the vaporizing portion 8 a. The exhaust gas exchanges heat with the steam passing through the gas-liquid separator 4. The other end of the liquidrefrigerant pathway 7 is connected to the bottom end portion of the gas-liquid separator 4. An opening/closing valve 7 a is provided to the liquidrefrigerant pathway 7. An opened/closed state of the opening/closing valve 7 a determines the supply of the liquid refrigerant from the gas-liquid separator 4 to the vaporizing portion 8 a. The liquid refrigerant supplied to the vaporizing portion 8 a is vaporized by heat of the exhaust gas that has superheated the steam at the superheatingportion 8 b. This increases a steam generation amount, improves the degree of superheating of the steam, and improves recovery efficiency of the exhaust heat. Asteam discharge pipe 3 a is provided to an upper end portion of the superheatingportion 8 b. Anozzle 9 is provided to a tip end portion of thesteam discharge pipe 3 a. - An
expander 10 is arranged at a downstream side of thesuperheater 8. Theexpander 10 is driven by vaporized refrigerant, i.e. steam, supplied from thesuperheater 8, and recovers energy. Theexpander 10 is a steam turbine including achassis 10 a and aturbine blade 10 b located in thechassis 10 a. Thenozzle 9 is mounted to thechassis 10 a so that the steam supplied through thesteam pathway 3 is injected toward theturbine blade 10 b. Thus, theturbine blade 10 b is rotary driven by the steam supplied through thesteam pathway 3. The rotative force of theturbine blade 10 b assists the rotation of the crankshaft included in theengine 1, and drives a power generator. This recovers the exhaust heat. - The
chassis 10 a of theexpander 10 is provided with afirst outlet 10 a 1 that discharges the steam, and asecond outlet 10 a 2 that discharges the liquid refrigerant produced by condensation of the steam in thechassis 10 a. Here, thesecond outlet 10 a 2 is provided to a downside portion of thechassis 10 a of theexpander 10 so as to discharge the liquid refrigerant in thechassis 10 a of theexpander 10. A diameter D2 of thesecond outlet 10 a 2 is smaller than a diameter D1 of thefirst outlet 10 a 1. That is to say, a relation of D2<D1 is established. - One end of a
first discharge path 11 is connected to thefirst outlet 10 a 1. The other end of thefirst discharge path 11 is connected to acondenser 12. Thefirst discharge path 11 discharges the steam from theexpander 10, and introduces the discharged steam into thecondenser 12. Thecondenser 12 condenses the steam by cooling the steam, and produces the liquid refrigerant. Thecondenser 12 receives blast by afan 13 and can cool and condense the steam efficiently. Arranged under thecondenser 12 is acondensed water tank 14 that reserves the liquid refrigerant produced in thecondenser 12. - One end of a
second discharge path 15 is connected to thesecond outlet 10 a 2. The other end of thesecond discharge path 15 is connected to thecondensed water tank 14. The above-describedsecond discharge path 15 discharges the liquid refrigerant from theexpander 10 to thecondensed water tank 14. The liquid refrigerant that has been cooled in thecondenser 12 is reserved in thecondensed water tank 14. The liquid refrigerant condensed in theexpander 10 is mixed with the liquid refrigerant cooled in thecondenser 12 and its temperature is decreased by being discharged to thecondensed water tank 14. A flow passage area S2 of thesecond discharge path 15 is smaller than a flow passage area S1 of thefirst discharge path 11. That is to say, a relation of S2<S1 is established. - At a downstream side of the
condensed water tank 14, provided is arefrigerant recovery passage 16 that re-circulates the liquid refrigerant, which is temporarily reserved in thecondensed water tank 14, to theengine 1 side. Therefrigerant recovery passage 16 is connected to the upstream side of the first water pump 6 in the refrigerant circulating path 5. Asecond water pump 17 is arranged in therefrigerant recovery passage 16. Thesecond water pump 17 is an electric vane pump. When thesecond water pump 17 is in an operational state, the liquid refrigerant in thecondensed water tank 14 is supplied to the refrigerant circulating path 5. In addition, aunidirectional valve 18 that prevents reverse flow of the refrigerant is provided downstream of thesecond water pump 17. As described above, theRankine cycle system 100 includes a passage where the refrigerant is circulated. - The relation of D2<D1 is established between the diameter D1 of the
first outlet 10 a 1 included in theRankine cycle system 100 and the diameter D2 of thesecond outlet 10 a 2 as described previously. In addition, the relation of S2<S1 is established between the flow passage area S1 of thefirst discharge path 11 included in theRankine cycle system 100 and the flow passage area S2 of thesecond discharge path 15. Maintaining the above relations is effective for preventing the steam from passing through thesecond outlet 10 a 2. In theRankine cycle system 100, it is desirable that the steam supplied into theexpander 10 is discharged from thefirst outlet 10 a 1 as much as possible. If the steam, which is vaporized refrigerant not condensed, is discharged from thesecond outlet 10 a 2, the steam passes through thesecond discharge path 15 and thecondensed water tank 14, and flows into thecondenser 12. That is to say, the steam flows from a direction different from a designed inflow direction into thecondenser 12. If the steam flows into thecondenser 12 from the direction different from the designed direction as described above, the function of thecondenser 12 is impaired. That is to say, thecondenser 12 cools and condenses the steam by heat exchange before the steam which has been introduced from the upper side thereof reaches thecondensed water tank 14, and produces the liquid refrigerant. If high-temperature steam flows from thecondensed water tank 14 side, the function of thecondenser 12 is impaired. Moreover, the temperature of the liquid refrigerant in thecondensed water tank 14 rises. The liquid refrigerant in thecondensed water tank 14 is supplied to theengine 1 again, and used for cooling theengine 1. Thus, it is required to keep the temperature of the liquid refrigerant in thecondensed water tank 14 as low as possible. - The
Rankine cycle system 100 satisfies a relation expressed by a following equation (1) in order to prevent the steam from being discharged from thesecond outlet 10 a 2. -
Δh>ΔPto/ρg equation (1) - Δh: difference between a liquid level in the
condensed water tank 14 and a lowest liquid level in thesecond discharge path 15
ΔPto: pressure loss when the steam flows in thecondenser 12 from theexpander 10 through thefirst discharge path 11
ρ: density of the liquid refrigerant
g: gravitational acceleration - Here, Δh in the present embodiment is equal to Δh1 as illustrated in
FIG. 1 andFIG. 2 . In addition ΔPto in the present embodiment is a pressure loss within a range indicated by B inFIG. 1 andFIG. 2 . - It is possible to prevent the steam from being discharged from the
second outlet 10 a 2 by satisfying the relation expressed by the equation (1). To satisfy the relation of the equation (1), it is effective to make the value of Δh as large as possible, and the value of ΔPto as small as possible. It is possible to make the value of ΔPto small by setting the diameter D1 of thefirst outlet 10 a 1 large or setting the flow passage area S1 of thefirst discharge path 11 large. - On the other hand, the
second discharge path 15 may be replaced with asecond discharge path 151 illustrated inFIG. 3 in order to set Δh large. As illustrated inFIG. 3 , a connected position P1 of thesecond discharge path 151 to thecondensed water tank 14 is located higher than alowest liquid level 151 a in thesecond discharge path 151. Thelowest liquid level 151 a is lowered by making thesecond discharge path 151 have a U-shape. This secures Δh2. As apparent fromFIG. 3 , Δh2 is larger than Δh1 when thesecond discharge path 15 is used. As a result, Δh2 easily satisfies the condition of the equation (1). - As described above, according to the Rankine cycle system disclosed in the present specification, it is possible to discharge the liquid refrigerant produced in the
expander 10 efficiently. As a result, it is possible to suppress deterioration and damage of the expander caused by production of the liquid refrigerant in theexpander 10. At this time, a special control device for discharging the liquid refrigerant from theexpander 10 is not necessary, and there is an advantage in cost. - The above described embodiments are merely examples for carrying out the present invention, and the present invention is not limited to the above-mentioned embodiments, and it is apparent from the above descriptions that other embodiments, variations and modifications may be made without departing from the scope of the present invention.
-
-
- 1 . . . engine
- 2 . . . exhaust pipe
- 3 . . . steam pathway
- 3 a 1 . . . steam discharge pipe
- 4 . . . gas-liquid separator
- 5 . . . refrigerant circulating path
- 6 . . . first water pump (W/P)
- 7 . . . liquid refrigerant pathway
- 8 . . . superheater
- 8 a . . . vaporizing portion
- 8 b . . . superheating portion
- 9 . . . nozzle
- 10 . . . expander
- 10 a . . . turbine chassis
- 10 b . . . turbine blade
- 11 . . . first discharge path
- 12 . . . condenser
- 13 . . . fan
- 14 . . . condensed water tank
- 15, 151 . . . second discharge path
- 16 . . . refrigerant recovery passage
- 17 . . . second water pump (W/P)
- 18 . . . unidirectional valve
- 100 . . . Rankine cycle system
Claims (6)
1. A Rankine cycle system comprising:
a superheater,
an expander that is driven by steam, which is vaporized refrigerant supplied from the superheater, to recover energy, and includes a first outlet discharging steam and a second outlet discharging liquid refrigerant produced by condensation of the steam in the expander;
a first discharge path that is connected to the first outlet and discharges the steam from the expander;
a condenser into which the steam is introduced through the first discharge path, and that condenses the steam into liquid refrigerant,
a condensed water tank that reserves the liquid refrigerant produced in the condenser; and
a second discharge path that connects the second outlet to the condensed water tank and discharges the liquid refrigerant from the expander, wherein
a liquid level in the condensed water tank satisfies a following relation:
Δh>ΔPto/ρg,
Δh>ΔPto/ρg,
when a height difference between the liquid level and a lowest liquid level in the second discharge path is expressed by Δh, a pressure loss when the steam flows into the condenser from the expander through the first discharge path is expressed by ΔPto, a density of the liquid refrigerant is expressed by ρ, and a gravitational acceleration is expressed by g.
2. The Rankine cycle system according to claim 1 , wherein
the second outlet is provided to a downside portion of the expander.
3. (canceled)
4. The Rankine cycle system according to claim 1 , wherein
a connected position of the second discharge path to the condensed water tank is located higher than the lowest liquid level in the second discharge path.
5. The Rankine cycle system according to claim 1 , wherein
a diameter of the second outlet is smaller than a diameter of the first outlet.
6. The Rankine cycle system according to claim 1 , wherein
a flow passage area of the second discharge path is smaller than a flow passage area of the first discharge path.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2010/055229 WO2011118000A1 (en) | 2010-03-25 | 2010-03-25 | Rankine cycle system |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130008165A1 true US20130008165A1 (en) | 2013-01-10 |
Family
ID=44672591
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/636,246 Abandoned US20130008165A1 (en) | 2010-03-25 | 2010-03-25 | Rankine cycle system |
Country Status (5)
Country | Link |
---|---|
US (1) | US20130008165A1 (en) |
JP (1) | JP5376046B2 (en) |
CN (1) | CN102812211B (en) |
DE (1) | DE112010005419B4 (en) |
WO (1) | WO2011118000A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170204775A1 (en) * | 2014-08-04 | 2017-07-20 | Toyota Jidosha Kabushiki Kaisha | Rankine cycle system |
US10253656B2 (en) | 2015-12-16 | 2019-04-09 | Toyota Jidosha Kabushiki Kaisha | Rankine cycle system for vehicle |
US10280808B2 (en) | 2015-12-16 | 2019-05-07 | Toyota Jidosha Kabushiki Kaisha | Rankine cycle system for vehicle |
US10294849B2 (en) * | 2014-08-05 | 2019-05-21 | Toyota Jidosha Kabushiki Kaisha | Cooling device having a refrigerant supply part of a condenser arranged higher than a shaft part of a turbine in a gravity direction |
CN110374700A (en) * | 2019-07-18 | 2019-10-25 | 中国电力工程顾问集团西南电力设计院有限公司 | A kind of gas-steam combined cycle set drained water recovery system |
Families Citing this family (4)
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JP5967171B2 (en) * | 2014-10-27 | 2016-08-10 | トヨタ自動車株式会社 | Boiling cooler |
CN108868916B (en) * | 2018-06-29 | 2020-11-20 | 东方电气集团东方汽轮机有限公司 | Water drainage device |
JP7147641B2 (en) * | 2019-03-18 | 2022-10-05 | いすゞ自動車株式会社 | Rankine cycle system and its control method |
CN114017954B (en) * | 2021-10-14 | 2022-08-05 | 华中科技大学 | Condenser and method for accelerating liquefaction of refrigerant by utilizing electric discharge |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1360748A (en) * | 1915-07-09 | 1920-11-30 | Nicolai H Hiller | Condenser and method of condensation |
US3685292A (en) * | 1971-03-19 | 1972-08-22 | Westinghouse Electric Corp | System and method for determining whether drain conduits for draining condensate from the turbine casing are clogged and clearing the conduits if they are |
US4425762A (en) * | 1981-04-28 | 1984-01-17 | Tokyo Shibaura Denki Kabushiki Kaisha | Method and system for controlling boiler superheated steam temperature |
US4471621A (en) * | 1980-12-16 | 1984-09-18 | Ormat Turbines, Ltd. | Method and apparatus for draining liquid working fluid from turbine cannister of a closed cycle power plant |
US7600526B2 (en) * | 2006-07-20 | 2009-10-13 | General Electric Company | Methods and apparatus for operating steam turbines |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2907068C2 (en) * | 1978-05-09 | 1983-09-15 | BBC Aktiengesellschaft Brown, Boveri & Cie., 5401 Baden, Aargau | Steam power plant for base load operation with equipment to cover load peaks |
JPS5560407U (en) * | 1978-10-23 | 1980-04-24 | ||
JPS643005U (en) * | 1987-06-24 | 1989-01-10 | ||
JPH04224209A (en) * | 1990-12-21 | 1992-08-13 | Mitsubishi Heavy Ind Ltd | Drain collecting apparatus for steam turbine |
US5494405A (en) * | 1995-03-20 | 1996-02-27 | Westinghouse Electric Corporation | Method of modifying a steam turbine |
JP3754527B2 (en) * | 1997-03-31 | 2006-03-15 | 東芝プラントシステム株式会社 | Drain pipe system |
CN100434665C (en) * | 2007-02-12 | 2008-11-19 | 西安交通大学 | Liquefied natural gas double-driving automobile circulatory system based on opening Rankine cycle |
JP2009103060A (en) | 2007-10-24 | 2009-05-14 | Toyota Motor Corp | Engine waste heat recovery system |
-
2010
- 2010-03-25 US US13/636,246 patent/US20130008165A1/en not_active Abandoned
- 2010-03-25 DE DE112010005419.3T patent/DE112010005419B4/en not_active Expired - Fee Related
- 2010-03-25 WO PCT/JP2010/055229 patent/WO2011118000A1/en active Application Filing
- 2010-03-25 JP JP2012506719A patent/JP5376046B2/en not_active Expired - Fee Related
- 2010-03-25 CN CN201080065724.4A patent/CN102812211B/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1360748A (en) * | 1915-07-09 | 1920-11-30 | Nicolai H Hiller | Condenser and method of condensation |
US3685292A (en) * | 1971-03-19 | 1972-08-22 | Westinghouse Electric Corp | System and method for determining whether drain conduits for draining condensate from the turbine casing are clogged and clearing the conduits if they are |
US4471621A (en) * | 1980-12-16 | 1984-09-18 | Ormat Turbines, Ltd. | Method and apparatus for draining liquid working fluid from turbine cannister of a closed cycle power plant |
US4425762A (en) * | 1981-04-28 | 1984-01-17 | Tokyo Shibaura Denki Kabushiki Kaisha | Method and system for controlling boiler superheated steam temperature |
US7600526B2 (en) * | 2006-07-20 | 2009-10-13 | General Electric Company | Methods and apparatus for operating steam turbines |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170204775A1 (en) * | 2014-08-04 | 2017-07-20 | Toyota Jidosha Kabushiki Kaisha | Rankine cycle system |
US10240512B2 (en) * | 2014-08-04 | 2019-03-26 | Toyota Jidosha Kabushiki Kaisha | Rankine cycle system |
US10294849B2 (en) * | 2014-08-05 | 2019-05-21 | Toyota Jidosha Kabushiki Kaisha | Cooling device having a refrigerant supply part of a condenser arranged higher than a shaft part of a turbine in a gravity direction |
US10253656B2 (en) | 2015-12-16 | 2019-04-09 | Toyota Jidosha Kabushiki Kaisha | Rankine cycle system for vehicle |
US10280808B2 (en) | 2015-12-16 | 2019-05-07 | Toyota Jidosha Kabushiki Kaisha | Rankine cycle system for vehicle |
CN110374700A (en) * | 2019-07-18 | 2019-10-25 | 中国电力工程顾问集团西南电力设计院有限公司 | A kind of gas-steam combined cycle set drained water recovery system |
Also Published As
Publication number | Publication date |
---|---|
CN102812211A (en) | 2012-12-05 |
DE112010005419B4 (en) | 2020-07-02 |
CN102812211B (en) | 2015-01-07 |
JPWO2011118000A1 (en) | 2013-07-04 |
DE112010005419T5 (en) | 2013-01-10 |
JP5376046B2 (en) | 2013-12-25 |
WO2011118000A1 (en) | 2011-09-29 |
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