U.S. patent application number 12/736752 was filed with the patent office on 2011-03-17 for stationary engine coolant circuit.
This patent application is currently assigned to Yanmar Co., Ltd.. Invention is credited to Shohei Amakawa, Toshiyuki Hayashi, Hirotoshi Kihara, Shojiro Matsumura.
Application Number | 20110061833 12/736752 |
Document ID | / |
Family ID | 41265122 |
Filed Date | 2011-03-17 |
United States Patent
Application |
20110061833 |
Kind Code |
A1 |
Kihara; Hirotoshi ; et
al. |
March 17, 2011 |
STATIONARY ENGINE COOLANT CIRCUIT
Abstract
The present invention has a waste heat recovery device (37) that
supplies engine waste heat by way of engine coolant; a radiator
(18) that dissipates engine waste heat by way of engine coolant; an
exhaust gas heat exchanger (33) that supplies engine waste heat
from exhaust gas to engine coolant; and a coolant pump (32) that
causes engine coolant to circulate. Furthermore, the constitution
is such that pressure drop equipment (34) is arranged upstream with
respect to a coolant pump suction region (32b); a restrictor is
arranged in a communication passage (50) between a coolant pump
suction region and a region (20) vented to atmosphere; a location
upstream with respect to the pressure drop equipment is made to
communicate with the region vented to atmosphere; and the region
vented to atmosphere is made capable of being kept in communication
with atmosphere.
Inventors: |
Kihara; Hirotoshi;
(Osaka-shi, JP) ; Amakawa; Shohei; (Osaka-shi,
JP) ; Hayashi; Toshiyuki; (Osaka-shi, JP) ;
Matsumura; Shojiro; (Osaka-shi, JP) |
Assignee: |
Yanmar Co., Ltd.
Osaka-shi, Osaka
JP
|
Family ID: |
41265122 |
Appl. No.: |
12/736752 |
Filed: |
April 24, 2009 |
PCT Filed: |
April 24, 2009 |
PCT NO: |
PCT/JP2009/058148 |
371 Date: |
November 5, 2010 |
Current U.S.
Class: |
165/51 |
Current CPC
Class: |
F01P 11/0285
20130101 |
Class at
Publication: |
165/51 |
International
Class: |
F01P 9/00 20060101
F01P009/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 7, 2008 |
JP |
2008-121521 |
Claims
1. A stationary engine coolant circuit having a waste heat recovery
device that supplies engine waste heat by way of engine coolant; a
radiator that dissipates engine waste heat by way of engine
coolant; an exhaust gas heat exchanger that supplies engine waste
heat from exhaust gas to engine coolant; and a coolant pump that
causes engine coolant to circulate, the stationary engine coolant
circuit being characterized in that it is constituted such that
pressure drop equipment is arranged upstream with respect to a
coolant pump suction region, and two of the coolant tanks are
provided; a vent pipe capable of being kept in communication with
atmosphere being provided at one of the tanks; and further, an air
pocket region at the one tank being made to communicate with an air
pocket region at the other tank; a location upstream with respect
to the pressure drop equipment being made to communicate with a
watersealed region at the other tank; and a restrictor being
arranged in a coupling passage between the location upstream with
respect to the pressure drop equipment and the watersealed
region.
2. A stationary engine coolant circuit according to claim 1, the
stationary engine coolant circuit being characterized in that the
exhaust gas heat exchanger is arranged at a location that is at a
discharge side of the coolant pump and that is downstream with
respect to the engine.
3. A stationary engine coolant circuit according to claim 1, the
stationary engine coolant circuit being characterized in that a
motor-driven three-way valve having an adjustable opening is
arranged at a region where a radiator downstream passage and a
waste heat recovery device downstream passage meet.
4. A stationary engine coolant circuit according to claim 1, the
stationary engine coolant circuit being characterized in that a
thermostat is arranged at a discharge side of the coolant pump; the
waste heat recovery device is arranged at a passage on a
high-temperature side of said thermostat; and a radiator is
arranged at a location downstream with respect to the waste heat
recovery device.
5. (canceled)
6. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a coolant circuit for a
stationary engine having a waste heat recovery device such as might
be employed in a GHP (gas heat pump) or a cogeneration system.
BACKGROUND ART
[0002] Disclosed conventionally as a coolant circuit for a
stationary engine having a waste heat recovery device, in the
context of an engine coolant circuit having a waste heat recovery
device, is a constitution in which a coolant pump suction region
communicates with a region vented to atmosphere (see, for example,
Patent Reference No. 1).
[0003] That is, the engine coolant circuit described in Patent
Reference No. 1 is equipped with a waste heat recovery device
constituted such that a radiator is in contact with an outdoor heat
exchanger. Moreover, the inlet region side of the coolant pump is
connected to a reserve tank, and the coolant pump suction port
communicates with atmosphere by way of a vent hole provided at the
reserve tank.
PRIOR ART REFERENCES
Patent References
[0004] PATENT REFERENCE NO. 1: Japanese Patent Application
Publication Kokai No. H09-88602 (1997)
SUMMARY OF INVENTION
Problem to be Solved by Invention
[0005] With the constitution of the engine coolant circuit of the
aforementioned Patent Reference No. 1, pressure at the coolant pump
suction region will be more or less equal to head pressure at the
reserve tank, and so long as the coolant pump is not arranged at a
location higher than the reserve tank, it will not be possible to
set the pressure at the pump suction region so as to be the same or
less than the head pressure.
[0006] However, an engine coolant circuit having a waste heat
recovery device is equipped with an exhaust gas heat exchanger for
causing engine heat to be absorbed by engine coolant from exhaust
gases prior to supply of engine waste heat by way of engine coolant
at the waste heat recovery device. Because it heats engine coolant,
there is a possibility that such an exhaust gas heat exchanger
might be treated as a type of boiler. Where the exhaust gas heat
exchanger is thus treated as a boiler, there will be a desire to
keep the pressure of that engine coolant as low as possible.
[0007] The present application therefore addresses the problem of
making it possible, in the context of an engine coolant circuit
having a waste heat recovery device, to adjust pressure as required
at a coolant pump suction region, which is where pressure in the
circuit is lowest, so as to be any desired pressure that is the
same or less than head pressure, for the purpose of setting
pressure within the coolant circuit of an exhaust gas heat
exchanger or the like so as to be a prescribed pressure.
Means for Solving Problem
[0008] The present invention, being conceived in order to solve the
aforesaid problem, is a stationary engine coolant circuit having a
waste heat recovery device that supplies engine waste heat by way
of engine coolant; a radiator that dissipates engine waste heat by
way of engine coolant; an exhaust gas heat exchanger that supplies
engine waste heat from exhaust gas to engine coolant; and a coolant
pump that causes engine coolant to circulate, the constitution
being such that a coolant pump suction region is made to
communicate with a region vented to atmosphere; a location upstream
with respect to the pressure drop equipment is made to communicate
with the region vented to atmosphere; a restrictor is arranged in a
communication passage between the region vented to atmosphere and
the location upstream with respect to the pressure drop equipment;
and the region vented to atmosphere is capable of being kept in
communication with atmosphere.
[0009] In such present invention, the pressure drop from the
pressure drop equipment makes it possible to cause pressure at the
coolant pump suction region to be lower than head pressure.
Furthermore, by adjusting flow rate at the restrictor in the
passage communicating with the region vented to atmosphere, it is
possible to adjust pressure so as to be any desired pressure within
a range from a negative pressure below atmospheric pressure to the
head pressure at the region vented to atmosphere. This being the
case, it is possible to set pressure within the coolant circuit to
be a prescribed pressure while maintaining engine coolant flow rate
so as to be equal to (pump suction region pressure+pump discharge
pressure+pressure drop to measurement location).
[0010] The exhaust gas heat exchanger in the aforesaid present
invention is arranged at a location that is at a discharge side of
the coolant pump and that is downstream with respect to the engine.
In such present invention, it is possible to cause pressure at the
inlet port of the exhaust gas heat exchanger to be (pump suction
region pressure+pump discharge pressure+pressure drop across flow
passages within engine), this being lower than (pump suction region
pressure+pump discharge pressure) by an amount corresponding to
(pressure drop across flow passages within engine).
[0011] In the aforesaid present invention, a motor-driven three-way
valve having an adjustable opening is arranged at a region where a
radiator downstream passage and a waste heat recovery device
downstream passage meet. In such present invention, because a
motor-driven three-way valve is arranged at a location in the
engine coolant circuit at which coolant temperature is lowest, heat
resistance of the motor-driven three-way valve is improved. Note
that the motor-driven three-way valve corresponds to one example of
the aforesaid pressure drop equipment.
[0012] In the aforesaid present invention, a thermostat is arranged
at a discharge side of the coolant pump; the waste heat recovery
device is arranged at a passage on a high-temperature side of said
thermostat; and a radiator is arranged at a location downstream
with respect to the waste heat recovery device. In such present
invention, when engine coolant temperature is at or above the
thermostat setpoint temperature, all coolant flow will be directed
to the waste heat recovery device. This being the case, when
calculating the amount of heat supplied from the engine coolant, as
compared with a constitution in which there is control of divided
flow with respect to the waste heat recovery device and the
radiator, calculation is simplified to the extent that there is no
need to take engine coolant flow ratio into account.
[0013] In the aforesaid present invention, the region vented to
atmosphere is constituted such that a vent pipe is provided at an
upper region of a coolant tank, the coolant pump suction region and
at least one of either the exhaust gas heat exchanger or the
radiator being made to communicate with a watersealed region of the
coolant tank. In such present invention, because a location in the
coolant circuit at which there is high probability of air pocket
formation is vented to atmosphere by way of a watersealed region,
it is possible to definitively carry out gas-liquid separation on
bubbles so that only engine coolant is returned to the circuit.
[0014] In the aforesaid present invention, the constitution is such
that two of the coolant tanks are provided; the vent pipe being
provided at one of the tanks; and further, an air pocket region at
one of the tanks being made to communicate with an air pocket
region at the other tank; the coolant pump suction region and at
least one of either the exhaust gas heat exchanger or the radiator
being made to communicate with a watersealed region at the other
tank; a watersealed region at one of the tanks being made to
communicate with a watersealed region at the other tank; and a
bottom of the tank provided with the vent pipe being arranged at
the same height or elevation as a bottom of the other tank. In such
present invention, because a constitution is adopted in which two
tanks are provided, it is possible to divide these in terms of
function such that one serves as reserve tank while the other
serves to allow gas-liquid separation of high-temperature bubbles
that rise up from within the circuit, permitting prevention of
elevated reserve coolant temperature as a result of gas-liquid
separation.
BENEFIT OF INVENTION
[0015] In the present invention, because the pressure drop from the
pressure drop equipment and adjustment of the opening at the
restrictor make it possible to adjust the pressure at the coolant
pump suction region so as to be any desired pressure that is the
same or less than head pressure, this can be set as required so as
to be the same or lower than atmospheric pressure.
BRIEF DESCRIPTION OF DRAWINGS
[0016] FIG. 1 is a circuit diagram showing an engine coolant
circuit in a cogeneration apparatus associated with one embodiment
of the present invention.
[0017] FIG. 2 is a front perspective view showing the entirety of
same cogeneration apparatus.
[0018] FIG. 3 is a rear perspective view showing the entirety of
same cogeneration apparatus.
[0019] FIG. 4 is a schematic drawing of a coolant tank.
EMBODIMENTS FOR CARRYING OUT INVENTION
[0020] Below, embodiments of the present invention are described
with reference to the drawings.
[0021] In the present embodiment, description is carried out in
terms of a situation in which the present invention is applied to a
cogeneration apparatus 1. Note that cogeneration apparatus 1 refers
to a system, where a commercial electric power subsystem of an
external commercial power supply and an electric power generation
subsystem of an electric generator are connected to an electric
power delivery subsystem that delivers electric power to electric
power consuming equipment (load), that meets the electric power
demand of said load, that recovers waste heat generated in
accompaniment to electric power generation, and that utilizes said
recovered heat.
[0022] FIG. 1 shows a circuit diagram of an engine coolant circuit
in the cogeneration apparatus, FIG. 2 shows a front perspective
view of same apparatus, and FIG. 3 shows a rear perspective view of
same apparatus.
[0023] As shown in FIG. 2 and FIG. 3, cogeneration apparatus 1
associated with the present embodiment is equipped with shell 2
serving as enclosure. The interior of this shell 2 is divided
vertically into two regions, the lower region comprising engine
chamber 3 and equipment housing chamber 5, and the upper region
comprising radiator chamber 7, intake chamber 8, and exhaust
chamber 9.
[0024] Arranged within the aforesaid engine chamber 3 there are an
engine 10, an electric generator 11 driven by this engine 10, and
an oil tank 12 storing lubricating oil.
[0025] The aforesaid equipment housing chamber 5 is arranged to the
side (right side as shown in FIG. 2) of engine chamber 3. Arranged
within equipment housing chamber 5 there are an inverter 14 and a
control box 17 equipped with a control apparatus 16 for controlling
engine drive equipment and so forth.
[0026] The aforesaid radiator chamber 7 is arranged above equipment
housing chamber 5, radiator 18 and coolant tank 20 being arranged
within this radiator chamber 7. Heat-dissipating radiator fan 19,
driving of which is controlled by the aforesaid control apparatus
16, is arranged above radiator chamber 7.
[0027] Respectively arranged at intake chamber 8 are air cleaner 22
and intake silencer 23. Arranged at exhaust chamber 9 is exhaust
silencer 24.
[0028] Next, referring to FIG. 1, the engine coolant circuit will
be described. This engine coolant circuit 30 is equipped with
coolant pump 32, which is the drive source for causing circulation
of engine coolant. Connected in order as one proceeds downstream
from the discharge side (coolant pump discharge region 32a) of this
coolant pump 32 there are coolant passages (water jacket) internal
to engine 10, exhaust gas heat exchanger 33, and thermostat 35.
[0029] Engine 10 might be a stationary gas engine using municipal
gas or the like as fuel, the exhaust system thereof being equipped
with the aforesaid exhaust gas heat exchanger 33 and the
aforementioned exhaust silencer 24. Furthermore, engine coolant
passing through engine 10 is sent to exhaust gas heat exchanger 33,
and after heat from exhaust gas is removed therefrom at exhaust gas
heat exchanger 33, is made to flow into thermostat 35 by way of
passage 31.
[0030] Thermostat 35 is equipped with passage 35a on the
low-temperature side thereof and passage 35b on the
high-temperature side thereof, the downstream end of
low-temperature passage 35a being connected to the inlet side
(coolant pump suction region 32b) of coolant pump 32. Furthermore,
the downstream end of high-temperature passage 35b is connected to
liquid-liquid heat exchanger 37 serving as waste heat recovery
device.
[0031] Thermostat 35 is such that when temperature of engine
coolant is below a prescribed temperature (e.g., when the engine is
first started), engine coolant is made to flow to low-temperature
passage 35a; and such that when engine coolant reaches a
temperature that is at or above a prescribed temperature, engine
coolant is made to flow to high-temperature passage 35b and
liquid-liquid heat exchanger 37.
[0032] Liquid-liquid heat exchanger 37 supplies heat removed from
engine coolant to the exterior, supplying heat to water flowing in
the secondary-water side 38 of a hot water supply, for example.
Respectively provided at locations upstream and downstream from
liquid-liquid heat exchanger 37 are temperature sensors 43, 44 for
detecting temperature of engine coolant.
[0033] Engine coolant that has passed through liquid-liquid heat
exchanger 37 is made to flow to radiator 18 and motor-driven
three-way valve 34. That is, motor-driven three-way valve 34
comprises a motor valve controlled by the aforesaid control
apparatus 16, and has three ports, these being first coolant inlet
34a, second coolant inlet 34b, and coolant outlet 34c.
[0034] Furthermore, connected to first coolant inlet 34a is the
downstream end of waste heat recovery device downstream passage 39,
which extends from liquid-liquid heat exchanger 37. Moreover,
connected to second coolant inlet 34b is the downstream end of
radiator downstream passage 40, which extends from radiator 18.
Accordingly, motor-driven three-way valve 34 is arranged at a
region where waste heat recovery device downstream passage 39 and
radiator downstream passage 40 meet. Note that waste heat recovery
device downstream passage 39 is connected by way of passage 42 to
radiator 18.
[0035] Furthermore, coolant outlet 34c is connected by way of
coolant supply pipe 41 to the aforesaid low-temperature passage
35a.
[0036] Motor-driven three-way valve 34 is such that the ratio
between the degree to which first coolant inlet 34a and second
coolant inlet 34b are opened is capable of being changed
(adjustment of opening), the opening ratio being determined in
correspondence to the amount of heat exchange occurring at
liquid-liquid heat exchanger 37. Specifically, when the amount of
heat exchange occurring at liquid-liquid heat exchanger 37 is
large, i.e., when the amount of heat being dissipated by engine
coolant is large, the degree to which first coolant inlet 34a is
opened will be large; and when the amount of heat exchange
occurring at liquid-liquid heat exchanger 37 is small, i.e., when
the amount of heat being dissipated by engine coolant is small, the
degree to which second coolant inlet 34b is opened will be
large.
[0037] The aforesaid coolant tank 20 comprises two tanks, one tank
(reserve tank) 20a being made of synthetic resin, and the other
tank (gas-liquid separation tank) 20b being made of metal.
Connected to the one tank 20a is a vent pipe 48 that is capable of
being kept in communication with atmosphere. The bottom of the
coolant at the one tank that is provided with vent pipe 48 is
arranged at the same height or elevation as the bottom of the other
tank, and moreover, respective air pocket regions at the one tank
20a and the other tank 20b are made to communicate by means of
communication pipe 46. Furthermore, watersealed regions of the two
tanks 20a, 20b (the portions thereof at which engine coolant is
stored) are made to communicate by way of communication pipe 47
which extends to the respective lower portions of the tanks.
[0038] The lower portion of the other tank 20b is connected by way
of communication pipe 45 to the upper portion 18a of radiator 18.
Furthermore, communication pipe 49 is connected between the lower
portion of the other tank 20b and plumbing (not shown), through
which engine coolant flows, within exhaust gas heat exchanger 33.
Radiator 18 and exhaust gas heat exchanger 33 are arranged at
elevation(s) higher than engine 10, the reason being that they are
locations within the coolant circuit that are susceptible to
formation of air pockets. By thus providing an air purge circuit
leading to a gas-liquid separation tank at location(s) where there
is danger of air pocket formation, this allows gas-liquid
separation to be carried out so that only engine coolant is
returned for intake by coolant pump 32.
[0039] Moreover, restrictors 60 and 61 are provided so as to
prevent excessive flow of engine coolant to communication pipes 45
and 49 and so as to adjust pressure at the inlet side of coolant
pump 32 to any desired pressure that is the same or less than head
pressure.
[0040] However, if it should become necessary to drastically reduce
pressure at coolant pump suction region 32b, the diameters of
restrictors 61, 60 may be increased, or the restrictors might be
removed from communication pipes 45, 49 and a restrictor 51 might
be provided at communication passage 50, so as to allow pressure
within the circuit to be adjusted to a lower value.
[0041] Cogeneration apparatus 1 of the present embodiment having
the foregoing constitution, operation with respect to circulation
in the coolant circuit will next be described.
[0042] Upon causing coolant pump 32 to operate, engine coolant
discharged from coolant pump 32 is supplied to engine 10, its
temperature becoming elevated as it cools cylinders and various
other locations while passing through the interior of engine 10,
and it moreover passes through exhaust gas heat exchanger 33 to
arrive at thermostat 35. At thermostat 35, when coolant temperature
is below a prescribed temperature, engine coolant is returned to
coolant pump 32.
[0043] Furthermore, when engine coolant reaches a temperature that
is at or above a prescribed temperature, thermostat 35 causes
engine coolant to flow to liquid-liquid heat exchanger 37. Here, in
the event that there is desire for supply of hot water, at
liquid-liquid heat exchanger 37, heat from engine coolant is
extracted to the exterior as it is used to heat water flowing in
the secondary-water side 38 of a hot water supply. Furthermore, the
amount of engine coolant flowing to radiator 18 is adjusted in
correspondence to the amount of heat exchange occurring at
liquid-liquid heat exchanger 37. When the amount of heat exchange
is large, the degree to which first coolant inlet 34a of
motor-driven three-way valve 34 is opened is greater than the
degree to which second coolant inlet 34b thereof is opened, and the
amount of coolant flowing through waste heat recovery device
downstream passage 39 and bypassing radiator 18 is large.
[0044] When the amount of heat exchange is small, the degree to
which second coolant inlet 34b of motor-driven three-way valve 34
is opened is greater than the degree to which second coolant inlet
34a thereof is opened, and the amount of coolant flowing to
radiator 18 is large.
[0045] Furthermore, the passage which goes from coolant pump
suction region 32b, through communication passage 50 and coolant
tank 20, to vent pipe 48 constitutes a line vented to atmosphere;
and because both the communication pipe 49 from exhaust gas heat
exchanger 33 and the communication pipe 45 from radiator 18, at
which the pressure within the coolant circuit is higher than at
coolant pump suction region 32b, go through restrictors 61, 60
before meeting at coolant tank 20, it is possible to cause the
pressure at coolant pump suction region 32b to be the same or less
than head pressure.
[0046] Furthermore, by providing exhaust gas heat exchanger 33
downstream with respect to engine 10, this makes it possible to
reduce the pressure drop by an amount corresponding to the
contribution from engine 10 and thus reduce the pressure acting at
exhaust gas heat exchanger 33.
[0047] By providing motor-driven three-way valve 34 at the suction
location of the pump, which is the location within the coolant
circuit where temperature is lowest, reliability with respect to
the part(s) employed for motor-driven three-way valve 34 is
improved. Moreover, with improved reliability it becomes possible
to use motor-driven three-way valve 34 over a long period and
achieve cost reduction.
[0048] When engine coolant temperature increases and the state of
thermostat 35 becomes such that the high-temperature side thereof
is opened, because all flow constantly goes through liquid-liquid
heat exchanger 37, it will be possible to calculate the amount of
heat exchange occurring at liquid-liquid heat exchanger 37 by
detecting the change in water temperature at temperature sensor 43
at the inlet side of liquid-liquid heat exchanger 37 versus
temperature sensor 44 at the outlet side thereof. This being the
case, as compared with the situation in which radiator 18 and
liquid-liquid heat exchanger 37 are arranged in paralleled fashion,
because computation of the amount of heat exchange no longer
requires a flowmeter at the passage leading to liquid-liquid heat
exchanger 37, cost reduction is made possible. Alternatively, as
compared with use of the ratio of opening relative to liquid-liquid
heat exchanger 37 at motor-driven three-way valve 34 to calculate
flow rate to liquid-liquid heat exchanger 37, computational load is
reduced.
[0049] Also, an air purge circuit leading to a gas-liquid
separation tank is provided at location(s) where there is danger of
air pocket formation, such as at exhaust gas heat exchanger 33 and
radiator 18. This being the case, bubbles mixed with engine coolant
at exhaust gas heat exchanger 33 and radiator 18 are, as shown at
FIG. 4, made to pass through communication pipe 49 and
communication pipe 45, to flow into the other tank 20b. Moreover,
only air passes through communication pipe 46 and enters the one
tank 20a, the air traveling through vent pipe 48 to be discharged
to atmosphere. Thus, because the constitution is such that
gas-liquid separation is carried out, with only engine coolant
being returned to the circuit interior, it is possible to reduce
the size of radiator 18, and it is also possible to prevent
cavitation at coolant pump 32. Note that engine coolant within the
one tank 20a moves as appropriate to the interior of the other tank
20b by way of communication pipe 47.
[0050] By carrying out gas-liquid separation of high-temperature
bubbles at the other tank (gas-liquid separation tank) 20b, which
is different from the one tank (reserve tank) 20a, it is possible
to prevent increase in water temperature at the reserve tank. In
addition, because increase in water temperature is prevented
thereat, the reserve tank may be manufactured easily and cheaply
from synthetic resin.
[0051] The present invention is not limited to the foregoing
embodiment. For example, as indicated by the imaginary line at FIG.
1, it is possible for the bottom of the coolant at the one tank
that is provided with vent pipe 48 to be arranged so as to be at
higher elevation than the bottom of the other tank. In such case,
it will be possible to more easily cause engine coolant within the
one tank 20a to move to the interior of the other tank 20b by way
of communication pipe 47.
[0052] Furthermore, it is also possible to employ the present
invention in an engine-driven heat pump. The present invention may
be embodied in a wide variety of forms other than those presented
herein without departing from the spirit or essential
characteristics thereof. The foregoing embodiments and working
examples, therefore, are in all respects merely illustrative and
are not to be construed in limiting fashion. The scope of the
present invention being as indicated by the claims, it is not to be
constrained in any way whatsoever by the body of the specification.
All modifications and changes within the range of equivalents of
the claims are, moreover, within the scope of the present
invention.
[0053] Moreover, this application claims priority based on Patent
Application No. 2008-121521 filed in Japan on 7 May 2008. The
content thereof is hereby incorporated in the present application
by reference.
POTENTIAL INDUSTRIAL USE
[0054] The stationary engine coolant circuit associated with the
present invention is effective as a coolant circuit for a
stationary engine having a waste heat recovery device, and is
particularly suited to use in a GHP (gas heat pump) or a
cogeneration system.
EXPLANATION OF REFERENCE NUMERALS
[0055] 1 Cogeneration apparatus [0056] 2 Shell [0057] 10 Engine
[0058] 18 Radiator [0059] 20 Coolant tank [0060] 20a The one tank
[0061] 20b The other tank [0062] 30 Engine coolant circuit [0063]
32 Coolant pump [0064] 32a Coolant pump discharge region [0065] 32b
Coolant pump suction region [0066] 33 Exhaust gas heat exchanger
[0067] 34 Motor-driven three-way valve [0068] 35 Thermostat [0069]
37 Liquid-liquid heat exchanger (waste heat recovery device) [0070]
39 Waste heat recovery device downstream passage [0071] 40 Radiator
downstream passage [0072] 41 Coolant supply pipe [0073] 42 Passage
[0074] 43 Temperature sensor [0075] 44 Temperature sensor [0076] 45
Communication pipe [0077] 46 Communication pipe [0078] 47
Communication pipe [0079] 48 Vent pipe [0080] 49 Communication pipe
[0081] 50 Communication passage [0082] 51 Restrictor [0083] 60
Restrictor [0084] 61 Restrictor
* * * * *