U.S. patent number 3,675,416 [Application Number 05/071,033] was granted by the patent office on 1972-07-11 for vapor power plant.
This patent grant is currently assigned to Nissan Motor Company Limited. Invention is credited to Riichi Maeda.
United States Patent |
3,675,416 |
Maeda |
July 11, 1972 |
VAPOR POWER PLANT
Abstract
A vapor power plant driven with a working fluid vaporized from a
liquid having a relatively freezing point such as
trichloromonofluoromethane, comprising a working fluid circuit and
a cooling fluid circuit both of which share limited common a
passage with each other so that the same liquid can be used both as
a working medium for driving a prime mover of the power plant and
as a cooling medium for cooling an exhaust from the prime
mover.
Inventors: |
Maeda; Riichi (Yokohama City,
JA) |
Assignee: |
Nissan Motor Company Limited
(Yokohama, JA)
|
Family
ID: |
13522204 |
Appl.
No.: |
05/071,033 |
Filed: |
September 10, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Sep 18, 1969 [JA] |
|
|
44/73575 |
|
Current U.S.
Class: |
60/671 |
Current CPC
Class: |
F01K
25/08 (20130101) |
Current International
Class: |
F01K
25/08 (20060101); F01K 25/00 (20060101); F01k
025/08 (); F01k 019/10 () |
Field of
Search: |
;60/36,95,39,40,94 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
3557554 |
January 1971 |
Martinek et al. |
|
Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Ostrager; Allen M.
Claims
What is claimed is:
1. A vapour power plant driven with a working fluid vapourized from
cool liquid including trichromonofluoromethane having a freezing
point lower than minus 30.degree. C and a boiling point lower than
95.degree. C, comprising a working fluid circuit including an
evaporator for vapourizing said cool liquid into a vapourized
working fluid, a regulator valve disposed between said evaporator
and a prime mover for adjusting the flow of said vapourized working
fluid to be fed to said prime mover, a cooling fluid circuit
including a cooling means, said working fluid and cooling fluid
circuits sharing a common condenser communicating with the outlet
ports of said prime mover and said cooling means and a common
liquid reservoir communicating with the inlet ports of said
evaporator and said cooling means, said working fluid circuit
having a first pump interposed between said reservoir and said
evaporator, and said cooling fluid circuit having a second pump
interposed between said reservoir and said cooling means, whereby
said cool liquid in said reservoir is passed by said first and
second pumps over to said evaporator and to said cooling means,
respectively.
2. A vapour power plant driven with a working fluid vapourized from
cool liquid including trichromonofluoromethane having a freezing
point lower than minus 30.degree. C and a boiling point lower than
95.degree. C, comprising an evaporator delivering a vapourized
working fluid, a prime mover communicating at its inlet port with
said evaporator for receiving the vapourized working fluid
therefrom, a regulator valve disposed between said evaporator and
said prime mover for adjusting the flow of said vapourized working
fluid to be delivered to said prime mover a vapour condenser
communicating at its inlet port with an outlet port of said prime
mover for receiving and liquefying an exhaust discharged therefrom,
a liquid reservoir communicating at its inlet with said condenser
for temporarily storing a cool liquid fed therefrom and
communicating at outlet port with an inlet port of said evaporator
through a first pump interposed between said reservoir and said
boiler and a cooling means communicating at its inlet port with a
second outlet port of said reservoir through a second pump and at
its outlet port with a second inlet port of said condenser, said
first and second pump feeding said cool liquid in said reservoir to
said evaporator and said cooling means, respectively, the liquid
forcedly cooled in said cooling means being fed into said condenser
for cooling and liquefying the exhaust discharged from said prime
mover in the succeeding cycle.
Description
This invention relates to a vapor power plant driven with vaporized
working fluid and more particularly to a method and apparatus
therefore of cooling from a prime mover of such power plant.
A vapor power plant has been proposed and put into limited practice
so as to supersede conventional internal combustion engines from
which noxious compounds such as carbon monoxides, hydrocarbons and
nitrogen oxides are emitted to the atmosphere causing serious air
pollution problems where the internal combustion engines are used
in motor vehicles. The vapor power plant, which is a variant of
external combustion engines, is driven with a working fluid which
is vaporized from a cool liquid. If, in this instance, it is not
desired for economical reasons to have an exhaust from the prime
mover discharged into the open air, the exhaust should be
repeatedly cooled and recycled in a closed circuit to drive the
prime mover continuously. Where water vapor is to be utilized as
such a working fluid, difficulties are encountered in that the
water tends to freeze in chilly weather to eventually destroy the
working circuit of the power plant and in that, where the exhaust
is forcedly air cooled, a large-sized, space-taking cooling unit
should be used to compensate for the low thermal conductivity
between the water vapor and air.
An object of the invention is therefore to provide an improved
method of cooling exhaust from a vapor power plant in which the
exhaust is free from freezing even in chilly weathers.
Another object of the invention is to provide an improved method of
cooling exhaust from a prime mover of a vapor power plant with an
increased performance efficiency and with use of a compact and
effective cooling unit.
Still another object is to provide a vapor power plant having means
to cool and liquefy exhaust discharged from a prime mover of a
power plant for repeated use or recycling of a working plant which,
on the other hand, is utilized as a medium for cooling the exhaust
recycled.
According to one aspect of the invention, it is herein proposed to
use as a working fluid for the vapor power plant those chemical
compounds which have a freezing point lower than minus 30.degree. C
at an atmospheric pressure. The working fluid may preferably have a
boiling point lower than 95.degree. C.
According to another important aspect of the invention, the same
liquid is utilized, on one hand, as a working fluid and, on the
other hand, as a cooling medium.
The method proposed by this invention as advantageous for cooling
the exhaust from the prime mover of the power plant consists of the
continuously repeated cycles each of which comprises contacting the
exhaust with forcedly cooled fluid for cooling down and liquefying
the exhaust into a liquid which is mixed with the cooled liquid
serving as a cooling medium, vaporizing a portion of the resultant
cool liquid into a working fluid for driving the prime mover, and
forcedly cooling the remaining portion of the cool liquid for
contact with the exhaust discharged successively from the prime
mover, wherein the liquid used for both driving the prime mover and
cooling the exhaust from the prime mover has a freezing point lower
than minus 30.degree. C. Thus, it will be readily appreciated that,
since the cooling medium used to carry out the method according to
the invention is of a liquid phase, a relatively high thermal
conductivity between the exhaust and the cooling medium is
available without use of a large-sized, space-taking cooling unit.
The use of a liquid with a relatively low freezing point, the
liquid is practically free from freezing when cooled down even in
unusually chilly weathers.
The method according to the invention is advantageously carried out
through provision of a vapor power plant comprising a working fluid
circuit including an evaporator for vaporizing a cool liquid into a
vaporized working fluid and a prime mover receiving the vaporized
working fluid from the evaporator and driven therewith, and a
cooling fluid circuit including a cooling means, the working fluid
and cooling fluid circuits sharing a common chamber communicating
with the outlet port of the prime mover and the cooling means and a
common liquid reservoir communicating with the inlet ports of the
evaporator and the cooling. Pumps, valves and other regulating
means may be provided between any of the components of the thus
constructed power plant.
The liquid which is advantageously operable in the method and
apparatus according to the invention is trichloromonofluoromethane,
butyl acetate, diethyl carbonate, butyl ether, O-dichlorobenzene,
monobromobenzene, hexafluorobenzene, trichlorotrifluoroethane, or a
mixture of two or more of these, but other fluoro- or hydrocarbons
may also be used, if desired.
Preferred embodiments of apparatus carrying out the method
described above are illustrated in the accompanying drawings in
which:
FIG. 1 is a schematic diagram showing an embodiment of a vapor
power plant incorporating the improvements according to the
invention; and
FIG. 2 is a view showing a modification of the power plant
illustrated in FIG. 1.
First referring to FIG. 1, the vapor driven power plant
incorporating the improvements according to the invention comprises
an evaporator 10 which is heated by an associated burning means 11
and which vaporizes a cool liquid supplied thereto. The evaporator
communicates at its outlet port with an inlet port of a prime mover
12 to which the working fluid vaporized in the evaporator 10 is
delivered. A regulator valve 13 may be interposed between the
outlet port of the evaporator 10 and the inlet port of the prime
mover 12, whereby the flow rate of the vapor is adjusted as
desired. The prime mover 12 communicates at its outlet port with an
inlet of a vapor condenser 14 through an exhaust passage 15,
whereby the exhaust discharged from the outlet port of the prime
mover 12 is fed into the condenser 14 in which the vapor is cooled
and liquefied as explained later. The condenser 14, in turn,
communicates at its outlet port with an inlet port of a liquid
reservoir 16 and the cool liquid in the condenser 14 is passed over
to the reservoir 16 for temporary storage. The reservoir 16
communicates at its outlet port with an inlet port of the boiler 10
through a feed pump 17 so that a portion of the cool liquid in the
reservoir is pumped by the feed pump 17 into the evaporator 10 for
vaporization into a working fluid. A closed working fluid circuit
is thus formed by the evaporator 10, prime mover 12, exhaust
passage 15, condenser 14 and liquid reservoir 16.
The burning means which is generally represented by reference
numeral 11 is made up, by way of example, of a fuel storage tank
11a containing fuel therein, a fuel pump 11b communicating with the
fuel storage tank 11a for pumping out the fuel therefrom, a fuel
flow regulator 11c adapted to regulate the flow rate of the fuel to
be passed therethrough, and a burner 11d which receives the fuel
from the regulator 11c and burns the fuel to heat the evaporator
10. The burning means 11 may be arranged otherwise insofar as the
purpose of heating the boiler 10 in a selected manner is
achieved.
The power plant shown in FIG. 1 includes another closed circuit for
the circulation and forced cooling of the liquid to cool and
liquefy the exhaust introduced into the condenser 14 from the prime
mover 12. This cooling fluid circuit comprises a circulating pump
18 which communicates with a second outlet of the liquid reservoir
16 for pumping out a portion of the cool liquid therefrom. The pump
18 communicates with an inlet port of a cooling means or radiator
19 so that the cool liquid is pumped into the cooling means or
radiator 19 and is therein forcedly cooled down. The cooling means
or radiator 19, in turn, communicates at its outlet port with a
second inlet of the condenser 14 through a cooling liquid passage
20 whereby the liquid which has been forcedly cooled down in the
cooling means or radiator 19 is drawn into the condenser chamber
14. The cooling fluid circuit is thus formed by the reservoir 16,
pump 18, cooling means or radiator 19 and condenser 14. In other
words, the drive fluid circuit and the cooling fluid loop share the
condenser 14 and the reservoir 16 with each other so that both of
the media for driving the prime mover 12 and cooling the exhaust
from the prime mover issue from or originate in a common source of
liquid which, in this instance, is the liquid reservoir.
When, in operation, the exhaust is discharged from the outlet port
of the prime mover 12 and introduced into the condenser 14, the
exhaust is brought into contact with the cooled liquid supplied
from the cooling means or radiator 19 and is thereby cooled down
and liquefied into the cool liquid. The thus cooled liquid is mixed
with the exhaust which therefore exchanges heat with the cooled
liquid.
The resultant cool liquid is passed over to the reservoir 16. A
portion of the cool liquid drawn into the reservoir is then pumped
into the evaporator 10 in which the cool liquid is converted into a
hot vapor. The major portion of the cool liquid in the reservoir 16
is drawn into the cooling means or radiator 19 by means of the
circulating pump 18 and is therein cooled and fed into the
condenser 14 for contact with the exhaust from the prime mover 12.
The cooling and drive media are in this manner recycled in the
cooling and working fluid circuits continuously, joining together
in the condenser 14 and reservoir 16 which are shared by the two
circuits.
The power produced by the prime mover 12 is carried to a suitable
driven member (not shown) through an output shaft 12a. Designated
by reference numeral 19a is a fan which forcedly air cools the
cooling means or radiator 19.
The constructions and operations of the components of the power
plant may be changed and modified in any desired manners as long as
the basic concept of the invention is maintained. For instance,
instruments for adjusting and/or regulating the performances of the
individual components of the power plant may be incorporated where
desired. Also, the circuit connections may be modified in a desired
manner, an example being shown in FIG. 2.
As illustrated in FIG. 2, a modification is made to the power plant
of FIG. 1 so that the evaporator 10 receives the cool liquid
directly from the cooling means or radiator 19 through a branch
passage 20a which is branched from the cooling liquid passage
20.
Now, the fuel to be used to heat the evaporator 10 may be gaseous,
liquid or solid and, moreover, the cooling means or radiator 19,
which has been described as cooled with atmospheric air, may be
cooled in any desired manner.
It may be herein noted that emission of toxic compounds resulting
from the combustion of a fuel to vapourize the working liquid in
the power plant of the invention can be minimized to a negligible
extent because the arrangement for heating the evaporator can be
selected desiredly and because the combustion of the fuel takes
place at an atmospheric pressure. The power plant according to the
invention is, therefore, expected to contribute to the solution of
the vehicular air pollution problems.
* * * * *