U.S. patent application number 13/528458 was filed with the patent office on 2012-12-20 for vapour power plant with hermetic turbogenerator.
Invention is credited to Aleksandra Borsukiewicz-Gozdur, Pawel Hanausek, Wojciech Klonowicz.
Application Number | 20120317982 13/528458 |
Document ID | / |
Family ID | 46650300 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120317982 |
Kind Code |
A1 |
Klonowicz; Wojciech ; et
al. |
December 20, 2012 |
VAPOUR POWER PLANT WITH HERMETIC TURBOGENERATOR
Abstract
The vapour power plant with hermetic turbogenerator is claimed,
such plant provided with the main thermal cycle that works with the
low boiling point fluid, and characterized by an additional,
internal working fluid cycle that serves to lubricate the slide
bearings contained in said hermetic turbogenerator, said additional
working fluid cycle consisting of the slide bearings supplying
piping connected to the main working fluid cycle at the main cycle
pump outlet, of the slide bearings housing, of the return piping
that directs the main portion of the working fluid liquid from said
slide bearing housing to the working fluid buffer container, and of
the emergency slide bearings supply piping that connects said
working fluid buffer container, through the emergency slide bearing
supply pump, with said slide bearings supply piping, whereby
non-return valves are provided before connection point of said
slide bearings supply piping and said emergency slide bearings
supply piping.
Inventors: |
Klonowicz; Wojciech; (Lodz,
PL) ; Hanausek; Pawel; (Lodz, PL) ;
Borsukiewicz-Gozdur; Aleksandra; (Przeclaw, PL) |
Family ID: |
46650300 |
Appl. No.: |
13/528458 |
Filed: |
June 20, 2012 |
Current U.S.
Class: |
60/645 ;
60/657 |
Current CPC
Class: |
F01K 25/08 20130101 |
Class at
Publication: |
60/645 ;
60/657 |
International
Class: |
F01K 13/00 20060101
F01K013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2011 |
PL |
P.395363 |
Claims
1. A vapour power plant with a hermetically sealed turbogenerator,
comprising a main thermal cycle that works with a low boiling point
fluid and extends consecutively from a preheater and evaporator
through the hermetically sealed turbogenerator consisting of the
vapor turbine placed together with the electric generator within a
common hermetic casing, next through a condenser, working fluid
buffer container, a main cycle pump and back to said preheater,
whereby said electric generator is cooled with the expanded vapour
from the said turbine outlet, and an inlet of the high pressure
working fluid vapour into said common hermetically sealed casing is
located in front of said turbine and the outlet of the expanded
working fluid vapour is in said common hermetic casing located
behind said electric generator, wherein an additional, internal
working fluid cycle that serves to lubricate the slide bearings
contained in said hermetic turbogenerator and that consists of the
slide bearings supplying piping (12) connected to the main working
fluid cycle at an outlet of said main cycle pump (8), of the slide
bearings housing (4), of the return piping (10) that directs the
main portion of the working fluid liquid from said slide bearing
housing (4) preferably to said working fluid buffer container (14),
and of the emergency slide bearings supply piping (18) that
connects said working fluid buffer container (14), through the
emergency slide bearing supply pump (15), with said slide bearings
supply piping (12), whereby said slide bearings supply piping (12)
and said emergency slide bearings supply piping (18) contain
non-return valves (16) and (17), respectively.
2. A method for producing vapour with a hermetic turbogenerator
comprising working with a main thermal cycle; employing low boiling
point fluid; and extending consecutively from a preheater and
evaporator through the hermetic turbogenerator; placing a vapour
turbine together with an electric generator within a common
hermetic casing, next through the condenser, working fluid buffer
container, main cycle pump and back to said preheater; cooling said
electric generator with an expanded vapour from the said turbine
outlet and the inlet of the high pressure working fluid vapour into
said common hermetic casing which is located in front of said
turbine and the outlet of the expanded working fluid vapour is in
said common hermetic casing located behind said electric generator,
wherein an additional, serving to lubricate the slide bearings
contained in said hermetic turbogenerator with an additional
internal working fluid cycle; consisting of slide bearings
supplying piping (12) connected to the main working fluid cycle at
the outlet of said main cycle pump (8), of the slide bearings
housing (4), of the return piping (10); directing the main portion
of the working fluid liquid from said slide bearing housing (4)
preferably to said working fluid buffer container (14), and of the
emergency slide bearings supply piping (18) that connects said
working fluid buffer container (14), through the emergency slide
bearing supply pump (15), with said slide bearings supply piping
(12), whereby said slide bearings supply piping (12) and said
emergency slide bearings supply piping (18) contain non-return
valves (16) and (17), respectively.
3. The vapour power plant with hermetic turbogenerator, with the
main thermal cycle that works with the low boiling point fluid and
extends consecutively from the preheater and evaporator through the
hermetic turbogenerator consisting of the vapour turbine placed
together with the electric generator within a common hermetic
casing, next through the condenser, working fluid buffer container,
main cycle pump and back to said preheater, whereby said electric
generator is cooled with the expanded vapour from the said turbine
outlet and the inlet of the high pressure working fluid vapour into
said common hermetic casing is located in front of said turbine and
the outlet of the expanded working fluid vapour is in said common
hermetic casing located behind said electric generator, wherein an
additional, internal working fluid cycle that serves to lubricate
the slide bearings contained in said hermetic turbogenerator and
that consists of the slide bearings supplying piping (12) connected
to the main working fluid cycle at the outlet of said main cycle
pump (8), of the slide bearings housing (4), of the return piping
(10) that directs the main portion of the working fluid liquid from
said slide bearing housing (4) preferably to said working fluid
buffer container (14), and of the emergency slide bearings supply
piping (18) that connects said working fluid buffer container (14),
through the emergency slide bearing supply pump (15), with said
slide bearings supply piping (12), whereby said slide bearings
supply piping (12) and said emergency slide bearings supply piping
(18) contain non-return valves (16) and (17), respectively.
Description
BACKGROUND AND GENERAL DESCRIPTION
[0001] The invention relates to the vapor power plant with hermetic
turbogenerator. The vapor power plant is based on the Organic
Rankine Cycle (ORC), i.e. on the thermal power plant cycle that
works with low boiling point fluids instead of water.
[0002] One known hermetic turbogenerator to work in vapor power
plants that are based on the thermal power plant cycle with low
boiling point fluids is disclosed in the Polish Patent Application
P 390472. This hermetic turbogenerator consists of an electric
generator and of a vapour turbine that are both placed in the
hermetic casing of the turbogenerator. The electric generator is
cooled with the working fluid vapour that has been expanded in the
vapour turbine. The inlet of the high pressure vapour of the
working fluid is arranged in the hermetic casing in front of the
vapour turbine, and the outlet of the expanded vapour is positioned
in the hermetic casing behind the electric generator. A system of
power generation known from the description of the invention
GB1083239 is based on thiophenc as the cycle working fluid that is
heated and evaporated in a vapour generator, expanded in a turbine,
cooled and condensed in a condenser and supplied back to the vapour
generator. In that invention, thiophene is used to lubricate the
turbine bearings. The invention does not relate to the hermetic
generator and does not incorporate any piping system attached to
the turbine bearings to return the lubricating fluid as its liquid
phase. A portable micro power plant operating with mercury vapour
as the working fluid is known from the invention U.S. Pat. No.
2,961,550. The system incorporates a hermetic turbogenerator and
its internal bearings are lubricated by the working fluid liquid
that is, under low pressure, supplied from the condenser. The
invention does not relate to the turbogenerator in which the
electric generator is cooled with the working fluid vapour, and can
not be applied to the cases where low boiling point fluids are used
as the cycle working fluids. A power plant known from the invention
US 20110047958 contains a vapour turbine with an electric
generator, an evaporator, a condenser, a cycle pump, and is working
with HFE as the cycle working fluid that is mixed with fluoric oil
acting as lubricant for the bearings. A fraction of the working
fluid with a high content of the lubricant is extracted from the
evaporator and is used to lubricate the rolling bearings. A method
to secure the lubrication of the high speed turbogenerator bearings
is known from the international publication WO 9205342. In this
method, for the case of the cycle working fluid pump emergency
stoppage, the ORC turbogenerator rotor slide bearings are
lubricated with the cycle working fluid supplied from the lower
part of the evaporator upon the principle that the evaporator
pressure would then increase. The solution does not apply to the
hermetic turbogenerator in which the electric generator is cooled
with the working fluid vapour, and it does not properly regard the
thermal process inertia that excludes the rotor bearings emergency
supply. A vapour power plant with the hermetic turbogenerator is
known from the Polish Patent Application P 390472. In that
solution, the electric generator placed together with the vapour
turbine inside a hermetic casing is cooled with the expanded
working fluid vapour. The inlet of the high pressure vapour is
located in the hermetic casing upstream to the turbine inlet. The
outlet of the expanded vapour is located in the hermetic casing
downstream to the electric generator position. The expanded vapour
of the working fluid flows around the electric generator and
carries away heat emitted by the generator.
[0003] The goal of the present invention is, for the standard ORC
power plant of moderate power output, to provide a solution that
(1) enables an effective lubrication of the slide bearings enclosed
in the hermetic turbogenerator that is cooled with the working
fluid vapour of the power plant cycle, that (2) provides effective
protection of the turbogenerator bearings lubrication in case of
the power plant cycle emergency stoppage, that (3) works without
lubricants other than the cycle working fluid and that (4) works
without the effect of lowering the power plant efficiency.
BRIEF DESCRIPTION OF THE DRAWING
[0004] In the accompanying drawing:
[0005] FIG. 1 is a schematic diagram showing main components of a
vapour power plant.
[0006] According to the present invention, the ORC power plant
contains the main thermal cycle of the working fluid, whereby that
cycle works with the low boiling point working fluid and extends
from the preheater and evaporator through the vapour turbine, the
latter being placed together with the electric generator in a
common hermetic casing to form the hermetic turbogenerator, next
through the condenser, the working fluid buffer container, the main
cycle pump and back to the preheater. The electric generator is
cooled by the expanded vapour of the working fluid, whereby the
high pressure vapour inlet is located in the common hermetic casing
upstream to the turbine and the expanded vapour outlet of the
common hermetic casing is located downstream to the electric
generator position. By virtue of the present invention, the ORC
power plant described above contains an additional, internal cycle
of the working fluid that serves for the slide bearing lubrication
and that consists of the slide bearings supplying piping, the
latter being attached to the main working fluid cycle downstream to
the main cycle pump, of the slide bearings housing and of the
return piping which directs the main portion of the working fluid
liquid from the slide bearings to the working fluid buffer
container and back to the main cycle pump. The remaining portion of
the working fluid liquid that, in the slide bearings labyrinth
seals, expands to the vapour phase is directed from the hermetic
casing to the condenser, jointly with the working fluid vapour
having been expanded in the turbine. An additional, emergency
supplying piping that incorporates an emergency working fluid pump
then connects the working fluid buffer container and the slide
bearing supplying piping. The emergency pump is activated in case
of cycle pump failure during the power plant operation. Both the
slide bearing supplying piping and emergency supplying piping
include non-return valves directly prior to piping connection
point.
[0007] The advantage of the present invention lies in continuous,
long lasting lubrication of the turbogenerator slide bearings, in
contrast to the relevant situation with the known hermetic
turbogenerator. This advantage effectively reduces maintenance
requirements in cases where the ORC power plant with hermetic
turbogenerator is used in real industrial conditions. In line with
the present invention, the relevant ORC power plant solution
enables the working fluid liquid as lubricant to be supplied to the
slide bearings at much higher pressure than that of the slide
bearings exterior. The homogeneity and cleanliness of the working
fluid, thus the unlowered efficiency of the power plant, are the
advantage of the solution with the working fluid as lubricant for
the hermetic turbogenerator slide bearings, when no other lubricant
is needed. There is then no need to seal the bearings to avoid
mixing of lubricant with the working fluid vapour. Complicated
systems of the lubricating oil sequestration and separation used in
standard bearing arrangements are eliminated. Moreover, as
operation of such oil sequestration and separation systems is not
perfect, lubrication of the turbogenerator bearings with the
working fluid eliminates the need to periodically replace the
working fluid in the power plant cycle as result of the working
fluid contamination that worsens the power plant efficiency. An
essential improvement according to the present invention is
provided by the solution that protects the turbogenerator slide
bearings against consequences of the power plant cycle pump
failure.
[0008] The invention is presented in more detail through a
description of its preferred embodiment supported by a drawing that
shows the vapour power plant incorporating the additional, internal
working fluid cycle for the turbogenerator slide bearing
lubrication.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] The main working fluid cycle of the ORC power plant converts
low temperature heat into mechanical energy that is then
transformed into electrical energy. A special working fluid, mostly
of organic nature, circulates in that cycle. The working fluid
liquid that flows through the preheater 6 and next through the
evaporator 5 extracts heat from the supplying energy carrier 9. The
working fluid being then in form of the hot working fluid vapor is
directed to the turbine 2 that, due to the working fluid vapor
expansion, generates mechanical power. The turbine 2 drives the
electric generator 3 by means of the common shaft connecting the
turbine and generator rotors. Both the turbine 2 and electric
generator 3 are placed in the common turbogenerator casing 1. The
electric generator 3 is cooled with the expanded working fluid
vapour coming from the turbine outlet. The expanded working fluid
vapour leaves the turbogenerator casing 1 and is directed, via the
piping 13, to the condenser 7 where it is cooled and condensed to
liquid phase with help of the cooling fluid 11. The resulting
working fluid liquid flows from the condenser 7 through the buffer
container 14 to the main cycle pump 8 that raises the working fluid
pressure. The pressurized working fluid liquid is then directed to
the preheater 6 and the whole working fluid circulation is
repeated.
[0010] The main working fluid cycle is supplemented by an
additional, internal working fluid cycle that serves for
lubrication of the turbogenerator slide bearings. The slide
bearings supply piping 12 is connected to the outlet of the main
cycle pump 8 and is used to supply the pressurized working fluid
liquid to the slide bearings housing 4. The pressurized working
fluid liquid lubricates the turbogenerator slide bearings and, at
the same time, its pressure drops. Then, the main portion of the
working fluid liquid is from the slide bearings housing returned to
the buffer container 14 by using the return piping 10. The
remaining portion of the working fluid liquid that, in the
labyrinth seals of the slide bearings housing, expands to the
vapour phase is, together with the working fluid vapour of the main
cycle, directed to the condenser 7. The slide bearings supply
piping 12 is additionally connected with the working fluid buffer
container 14 via the emergency supply piping 18 that incorporates
the emergency supply pump 15. Both the slide bearings supply piping
12 and the emergency supply piping 18, upstream to their connection
point, are equipped with non-return valves, 16 and 17 respectively.
In case of the main cycle pump failure, or when the working fluid
pressure in the main cycle unexpectedly drops because of other
reasons, the power plant control system decouples the electric
generator from the electric network and activates the emergency
supply pump 15 to allow for a safe stoppage of rotating elements of
the turbogenerator.
* * * * *