JPH11257155A - Method for starting external combustion-type heat gas engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a starter motor and to reduce the weight without forming a special structure in order to reduce starting torque. SOLUTION: In a method for starting an external combustion-type heat gas engine 1, for driving a starter motor 9 connected to a crank shaft 10 and for starting the operation, the crank shaft 10 is so rotated that a low- temperature side displacer piston 3 may be positioned in the approximately central position C of the piston stroke in relation to a low-temperature side cylinder 44. Next, the low-temperature side displacer piston 3 is positioned in the approximately central position C of the piston stroke for the specified time, the differential pressure ΔP between internal pressure of a low-temperature chamber 15 and a crank chamber 47 which are divided by the low-temperature side cylinder 44 and the low-temperature side displacer piston 3 is made to zero, and then the starter motor is driven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting an external combustion type hot gas engine using a starter motor to start an external combustion type hot gas engine suitable as a cooling / heating heat source for a cooling / heating device or a hot water supply device.

[0002]

2. Description of the Related Art In recent years, as a device for cooling, heating and hot water supply,
A heat pump (Vuilleumier Cycle Heat Pump) using a Vilmier cycle as an external combustion type heat gas engine has been developed. This external-combustion hot gas engine causes a pressure change only by a change in the temperature distribution of He (helium) gas as a sealed medium (working gas), thereby enabling direct cooling / heating / hot water supply (for example, Fairness 5-65777
Or JP-A-4-113170).

In this external combustion type hot gas engine, the high temperature side displacer piston is reciprocally accommodated in the high temperature side cylinder of the high temperature side pressure vessel, and the low temperature side displacer piston is accommodated in the low temperature side cylinder of the low temperature side pressure vessel. The two displacer pistons are connected to a crankshaft via a piston rod and a connecting rod, respectively, and working gas is filled and sealed in both pressure vessels.

In this type of external combustion type hot gas engine, when the operation is started, the crankshaft is forcibly rotated by a starter motor, whereby the high temperature side displacer piston and the low temperature side displacer piston are reciprocated. Is ignited, the heater connected to the high temperature chamber in the high temperature side pressure vessel is heated, and the external combustion type hot gas engine operates independently.

According to the external combustion type hot gas engine described above, theoretically, the piston rods rotate independently even if the diameters of the high-temperature side and low-temperature side piston rods are small, but in actual engines, each heat exchanger (heater) , Medium temperature heat exchanger, low temperature heat exchanger, high temperature regenerator,
Since there is a pressure loss in the low-temperature regenerator, if the diameters of the piston rods on the high-temperature side and the low-temperature side are small, they do not rotate independently.
Therefore, in an actual engine, the diameter of the piston rod on the low-temperature side is usually increased to increase the pressure loss of each heat exchanger (heater, medium-temperature heat exchanger, low-temperature heat exchanger, high-temperature regenerator, low-temperature regenerator). It is manufactured so that it can rotate independently even if it is large.

However, when the diameters of the high-temperature side and low-temperature side piston rods increase, the working chambers (high-temperature chamber, medium-temperature chamber, and low-temperature chamber) are compressed by the operation and compression of the high-temperature side and low-temperature side piston rods. A pressure difference is generated between the crank chamber that houses the crankshaft and the crank chamber. For this reason, the larger the diameters of the piston rods on the high temperature side and the low temperature side, the larger the required starting torque.

Conventionally, in order to start the above-mentioned external combustion type hot gas engine, a large capacity starter motor for generating a starting torque required at the time of starting the hot gas engine has been installed (first prior art). A bypass passage is provided to enable communication between the medium temperature chamber and the like and the crank chamber and the like.
There is proposed an on-off valve that opens only when the external combustion type hot gas engine is started to reduce the starting torque (second prior art).

[0008]

However, when a large-capacity starter motor is employed as in the first prior art, the size of the starter motor is increased and its weight is increased, and the overall weight of the external combustion type hot gas engine is increased. Will also increase.

Further, when a bypass passage having an on-off valve is provided between the middle temperature chamber and the crank chamber as in the second prior art, a special structure is provided to reduce the starting torque. , Cost increases are inevitable.

SUMMARY OF THE INVENTION [0010] The object of the present invention has been made in view of the above-mentioned circumstances, and it is possible to reduce the size and weight of a starting motor without using a special structure for reducing the starting torque. An object of the present invention is to provide a method of starting an engine.

[0011]

According to the first aspect of the present invention,
The high temperature side displacer piston is placed in the high temperature side cylinder,
The low-temperature side displacer piston is housed in the low-temperature side cylinder so as to be reciprocally movable, and both of these displacer pistons are connected via a piston rod to a crankshaft arranged in the crank chamber. In the starting method of the external combustion type hot gas engine, the piston rod is formed to have a larger diameter than the piston rod on the high temperature side displacer piston side and starts operation by driving a starter motor connected to the crankshaft. Rotating the crankshaft to position the low-temperature side displacer piston at a substantially central position of the piston stroke with respect to the low-temperature side cylinder; Only by the difference in internal pressure between the working chamber and the crank chamber defined by the low-temperature cylinder and the low temperature side displacer piston to zero, then
The starter motor is driven.

The first aspect of the invention has the following operation.

The crankshaft is rotated by a predetermined angle so that the low-temperature side displacer piston is positioned substantially at the center of the piston stroke with respect to the low-temperature side cylinder. Position it,
Since the difference between the internal pressures of the working chamber and the crank chamber in the low temperature side cylinder is set to zero, and then the starter motor is driven, the low temperature side displacer piston is moved from the approximate center position of the piston stroke to the top dead center side or below. The change in volume due to the movement of the piston rod into and out of the working chamber in the low temperature side cylinder when moving to the dead center side is smaller than when the low temperature side displacer piston is moved from another position to the top dead center side or the bottom dead center side. small. For this reason, the difference in internal pressure between the working chamber and the crank chamber in the low-temperature cylinder is also better when the low-temperature displacer piston is moved from the approximate center position of the piston stroke to the top dead center or the bottom dead center. It is smaller than when the low temperature side displacer piston is moved from another position to the top dead center side or the bottom dead center side. As a result, the starting torque required for crankshaft rotation at the time of starting, which is determined based on the difference between the internal pressures, also lowers the low-temperature side displacer piston from the approximate center position of the piston stroke to the top dead center side or the lower side. It is smaller when moving to the dead center side than when moving the low temperature side displacer piston from another position to the top or bottom dead center side. Therefore, the starting motor for rotating the crankshaft at the time of starting can be reduced in size and weight.

Further, at the time of starting the operation, the position of the low temperature side displacer piston is located at substantially the center of the piston stroke with respect to the low temperature side cylinder, and the starting torque required at the time of starting the operation is reduced by merely waiting at this position for a predetermined time. Since it is possible, there is no need to provide a special structure for reducing the starting torque, and the cost does not increase.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a chilled / hot water circuit of a heat pump type air conditioner equipped with an external combustion type hot gas engine for carrying out an embodiment of a method for starting an external combustion type hot gas engine according to the present invention. FIG.

The external combustion type hot gas engine 1 includes a high temperature side displacer piston 2 and a low temperature side displacer piston 3 which are arranged orthogonally to each other, and these are housed in a container described later in which a working gas such as helium is sealed. I have. The interior of the container includes a high-temperature chamber 12, medium-temperature chambers 13 and 14, and a low-temperature chamber 1.
5 is divided. Further, a heater 16 is provided at an end of the high temperature chamber 12, and the heater 16 is heated by the combustor 11.

The displacer pistons 2 and 3 are connected to the crankshaft 10 via piston rods 2a and 3a, respectively, so as to operate with a phase shift of 90 ° from each other. When the high-temperature side displacer piston 2 and the low-temperature side displacer piston 3 operate, the sealed working gas passes through the high-temperature regenerator 4 and the low-temperature regenerator 7 and passes through the high-temperature chamber 12, the medium-temperature chamber 13, the medium-temperature chamber 14, and the low-temperature chamber 15 Move between. The working gas is heated or cooled when passing through the regenerators 4 and 7, so that the pressure in the closed vessel is increased or reduced.

For example, when the working gas in the high-temperature chamber 12 moves to the middle-temperature chamber 13 through the high-temperature regenerator 4, the heat energy of the working gas is stored in the high-temperature regenerator 4, and the pressure of the working gas decreases. . Conversely, when the working gas recirculates from the medium temperature chamber 13 to the high temperature chamber 12, the thermal energy stored in the high temperature regenerator 4 is released to the working gas, and the pressure of the working gas increases. When the working gas in the low-temperature chamber 15 moves to the medium-temperature chamber 13 through the low-temperature regenerator 7, the working gas is supplied with the heat energy of the low-temperature regenerator 7, and the pressure of the working gas also increases. Conversely, when the working gas recirculates from the medium temperature chamber 14 to the low temperature chamber 15, the heat energy of the working gas is
And the pressure of the working gas decreases.

The exchange of heat energy with the outside is performed by the heater 16, the medium-temperature heat exchangers 5, 6 communicating with the medium-temperature chambers 13, 14, and the low-temperature heat exchanger 8 communicating with the low-temperature chamber 15, respectively. And do.

For example, when the heater 16 gives thermal energy to the working gas in the high temperature chamber 12, the working gas in the medium temperature chambers 13 and 14 emits heat energy to the external heat medium via the medium temperature heat exchangers 5 and 6. At the same time, the working gas in the low-temperature chamber 15 absorbs heat energy from the external heat medium via the low-temperature heat exchanger 8.

That is, in the external combustion type hot gas engine 1 of the present embodiment, the low temperature heat exchanger 8 and the low temperature chamber 15 constitute a heat absorbing portion, while the medium temperature heat exchangers 5 and 6 and the medium temperature chambers 13 and 14 are provided. Constitute a heat radiating portion, and the air conditioner 100 is configured using the low-temperature heat exchanger 8 and the medium-temperature heat exchangers 5 and 6 of the external combustion type heat gas engine 1. The air conditioner 100 includes an external combustion type hot gas engine 1, an indoor unit 200, and an outdoor unit 300.

An indoor heat exchanger 201 is provided in the indoor unit 200, and an outdoor heat exchanger 301 is provided in the outdoor unit 300. 203 is an indoor fan and 303 is an outdoor fan. The low-temperature heat exchanger 8 and the indoor heat exchanger 201 are connected by a pipe 21, a four-way valve 36 and a pipe 22, and the indoor heat exchanger 201 and the low-temperature heat exchanger 8 are further connected by a pipe 23 and a four-way valve 37. It is connected to a pipe 24.

The intermediate heat exchanger 5 and the outdoor heat exchanger 30
1 is connected by a pipe 31, a four-way valve 36 and a pipe 32, and the outdoor heat exchanger 301 and the medium temperature heat exchanger 6 are connected by a pipe 33, a four-way valve 37 and a pipe 34. The intermediate-temperature heat exchangers 5 and 6 are connected by a pipe 35. Water (hereinafter, referred to as liquid refrigerant) is used as an external heat medium circulating in the pipeline.

Here, reference numeral 9 denotes a starter motor,
When the external combustion type hot gas engine 1 is started, the crankshaft 10 is forcibly rotated to forcibly reciprocate the high temperature side displacer piston 2 and the low temperature side displacer piston 3. External combustion type hot gas engine 1 using this starter motor 9
During the start of the combustion, the combustor 11 is ignited and the external combustion type hot gas engine 1
Is operated independently, and then the starter motor 9 is stopped.

At the time of cooling operation, the hot gas engine 1 is operated by the ignition of the combustor 11, and the heat energy of the working gas is released to the liquid refrigerant through the medium temperature heat exchangers 5 and 6, while the low temperature heat exchanger is The heat energy of the liquid refrigerant is absorbed by the working gas through the pipe 8. At this time, the four-way valves 36 and 37 are switched as shown by the solid line in FIG. 1, and the liquid refrigerant that has released the heat energy in the low-temperature heat exchanger 8 is supplied to the pipeline 21 and the four-way valve 3.
6. It flows to the indoor heat exchanger 201 via the pipe 22.
In the indoor unit 200, the indoor heat exchanger 201 which has become low temperature
Is blown from the indoor fan 203, cool air is blown into the room (cooling is performed), and the liquid refrigerant that has absorbed the heat energy of the indoor unit 200 flows through the pipe 23, the four-way valve 37, and the pipe 2
The refrigerant is returned to the low-temperature heat exchanger 8 via 4.

At this time, the liquid refrigerant having absorbed the heat energy in the intermediate-temperature heat exchanger 5 is supplied to the pipe 31, the four-way valve 36, and the pipe 32.
Through the outside fan 303, where it is cooled by the air blown from the outdoor fan 303, flows through the pipe 33, the four-way valve 37, and the pipe 34 to the middle-temperature heat exchanger 6, and further through the pipe 35 to exchange medium-temperature heat. Reflux to vessel 5.

Also, during the heating operation, the hot gas engine 1 is operated by the ignition of the combustor 11, and the heat energy of the working gas is absorbed by the liquid refrigerant through the medium-temperature heat exchangers 5 and 6, while the low-temperature The heat energy of the liquid refrigerant is released to the working gas via the heat exchanger 8, and at this time, the four-way valves 36 and 37 are switched as shown by the dotted lines in FIG.

In this case, the liquid refrigerant having absorbed the heat energy in the intermediate-temperature heat exchangers 5 and 6 flows to the indoor heat exchanger 201 via the pipe 31, the four-way valve 36 and the pipe 22.

In the indoor unit 200, air is blown from the indoor fan 203 to the indoor heat exchanger 201, which has become relatively high temperature, so that warm air is blown into the room (heating is performed). The liquid refrigerant that has released energy is connected to line 2
3, the intermediate temperature heat exchanger 5 via the four-way valve 37 and the pipe 34
Reflux to 6.

At this time, the liquid refrigerant that has released the thermal energy in the low-temperature heat exchanger 8 is supplied to the pipe 21, the four-way valve 36, and the pipe 32.
Then, after flowing into the outdoor heat exchanger 301 through the outdoor fan 303 to absorb the heat energy of the outside air, the air flows back to the low-temperature heat exchanger 8 via the pipe 33, the four-way valve 37, and the pipe 24.

Here, the structure of the external combustion type hot gas engine 1 will be described in more detail with reference to FIGS.

The high temperature side displacer piston 2 is accommodated in the high temperature side pressure vessel 40, and the low temperature side displacer piston 3 is accommodated in the low temperature side pressure vessel 41 so as to be reciprocally movable as described above. Also, the crankshaft 1
0 is connected to the high temperature side displacer piston 2 and the low temperature side displacer piston 3 via the piston rods 2a, 3a and the connecting rods 2b, 3b, respectively, as described above, and is rotatably housed in the crank chamber 47 of the crank case 42. You. The high temperature side pressure vessel 40 and the low temperature side pressure vessel 41 are bolted to the crankcase 42 in an orthogonal state.

The high temperature side pressure vessel 40 includes a high temperature side cylinder 43 for reciprocating the high temperature side displacer piston 2 by slidingly contacting the high temperature side displacer piston 2, and a high temperature regenerator 4 and a medium temperature heat exchanger 5 are disposed outside the high temperature side cylinder 43. Is done. The high-temperature side cylinder 43 and the high-temperature side pressure vessel 40 have a high-temperature side displacer piston 2 inside the high-temperature side chamber 12 and the middle-temperature side chamber 1.
It is divided into three.

The low-temperature side pressure vessel 41 includes a low-temperature side cylinder 44 for reciprocating the low-temperature side displacer piston 3 by slidingly contacting the low-temperature side displacer piston 3. A medium-temperature heat exchanger 6 and a low-temperature heat exchanger 8 are respectively disposed on both sides of a low-temperature regenerator 7 outside the above. The low-temperature side cylinder 44 and the low-temperature side pressure vessel 41 have a low-temperature side displacer piston 3.
The compartment is divided into a medium temperature room 14 and a low temperature room 15.

The above-mentioned high temperature room 12, medium temperature room 13, medium temperature room 1
4, the low-temperature chamber 15, the high-temperature regenerator 4, the medium-temperature heat exchanger 5, the medium-temperature heat exchanger 6, the low-temperature regenerator 7, and the low-temperature heat exchanger 8 are filled with working gas. Medium temperature chamber 1 of high temperature side pressure vessel 40
The medium-temperature chamber 13 and the medium-temperature heat exchanger 5 are connected by a connection duct 45 connecting the third side and the low-temperature side pressure vessel 41 to the medium-temperature room 14 side.
The movement of the working gas in the inside and the working gas in the middle temperature room 14 and the middle temperature heat exchanger 6 is enabled.

In the crankcase 42, a partition wall 48 for partitioning the crank chamber 47 from the medium temperature chamber 13 on the high temperature side pressure vessel 40 side is provided. Are partitioned by bolts. And these partition walls 48, 49
The seal members 50 slidingly contact the outer peripheral surfaces of the piston rod 2a on the high temperature side displacer piston 2 side and the piston rod 3a on the low temperature side displacer piston 3 side, respectively.
Is installed. This seal material 50 prevents the working gas in the medium temperature chambers 13 and 14 from leaking into the crank chamber 47 when the external combustion type hot gas engine 1 is operating, and
3, 14, the pressure in the crank chamber 47 is optimized. However, when the operation of the external combustion type hot gas engine 1 is stopped,
The working gas in 3, 14 and the crank chamber 47 is the sealing material 5
The pressure in the medium temperature chambers 13 and 14 and the crank chamber 47 is equalized by flowing out and in through the zero.

The outer diameter of the piston rod 3a on the low-temperature side displacer piston 3 side is provided to be larger than the outer diameter of the piston rod 2a on the high-temperature side displacer piston 2 side.
Of the external combustion type hot gas engine 1 by itself.

A start-up method for driving the starter motor 9 connected to the crankshaft 10 to start the external combustion type hot gas engine 1 will be described below.

Before explaining the starting method, the pressure difference Δ between the pressure P1 in the low-temperature chamber 15 and the pressure P2 in the crank chamber 47 will be described.
P (ΔP = P1−P2) is determined using FIG. 3 and based on this pressure difference ΔP, and the starting torque T of the external combustion type hot gas engine 1 required for rotation of the crankshaft 10 is determined. Will be described with reference to FIG.

As shown in FIG. 3, the pressure P2 in the crank chamber 47 is constant when the external combustion type hot gas engine 1 is operating and when it is stopped. The pressure P1 in the low temperature chamber 15
When the operation of the external combustion type hot gas engine 1 is stopped, the pressure becomes equal to the pressure P2 in the crank chamber 47 due to the leakage of the working gas from the sealing material 50 of the partition wall 49. Is zero. During operation of the external combustion type hot gas engine 1 (including when the starter motor 9 is started), the reciprocating movement of the low temperature side displacer piston 3 causes the piston rod 3a to move into and out of the medium temperature chamber 14, whereby the volume of the medium temperature chamber 14 is increased. Changes, so this medium greenhouse 1
The pressure P1 in the low-temperature chamber 15 communicating with 4 fluctuates, and accordingly, the pressure difference ΔP also fluctuates.

As shown in FIG. 5, the pressure difference ΔP differs depending on the piston stroke position of the low temperature side displacer piston 3 when the external combustion type hot gas engine 1 is started, that is, the rotation stop position of the crankshaft 10. That is,
When the low temperature side displacer piston 3 is at the top dead center position A (when the crankshaft 10 is at the crank angle 0 degree position a) at the time of starting the external combustion type hot gas engine 1, the low temperature side displacer piston 3 is bottom dead. Since the volume change due to the ingress and egress of the piston rod 3a of the medium temperature chamber 14 is large until the position moves to the point position B (when the crankshaft 10 is at the crank angle 180 degree position b), the pressure difference ΔP is represented by the thin solid line in FIG. As shown by α1, it is zero at the time of startup, but the low-temperature side displacer piston 3 is substantially at the center position C between the top dead center position A and the bottom dead center position B (the crankshaft 10 is at the crank angle 90 ° position c. When moving to (case), it becomes approximately -2 (dimensionless amount), and when moving to the bottom dead center position B, it becomes approximately -4 (dimensionless amount).

On the other hand, when the external combustion type hot gas engine 1 is started, the low temperature side displacer piston 3 is positioned substantially at the center C between the top dead center position A and the bottom dead center position B (when the crankshaft 10 is at a crank angle of 90 degrees). c (the position of the low-temperature side displacer piston 3 in FIG. 2), the piston rod 3a of the medium temperature chamber 14 is moved until the low-temperature side displacer piston 3 moves to the top dead center position A or the bottom dead center position B. Since the change in volume due to entry and exit is the smallest, the pressure difference ΔP
As shown by the thick solid line β1, the value is zero at the time of startup, but when the low-temperature side displacer piston 3 moves to the bottom dead center position B (when the crankshaft 10 is at the crank angle position 180 degrees b), about- 2 (dimensionless quantity).

When the external combustion type hot gas engine 1 is started, the low temperature side displacer piston 3 is located between the top dead center position A and the substantially center position C (for example, when the crankshaft 10 is at a crank angle of 30 degrees, or When the low-temperature side displacer piston 3 moves to the bottom dead center position B, the volume change due to the insertion / removal of the piston rod 3a of the medium-temperature chamber 14 occurs when the low-temperature side displacer piston 3 is started. Is larger than that at the substantially center position C, the pressure difference ΔP is equal to the broken line γ in FIG.
1, as indicated by the dashed-dotted line δ1, is larger than the thick solid line β1.

Next, the starting torque T of the external combustion type hot gas engine 1 will be described with reference to FIG. The force F acting on the low-temperature side displacer piston 3 is obtained by multiplying the pressure difference ΔP between the pressure P1 in the low-temperature chamber 15 and the pressure P2 in the crank chamber 47 by the cross-sectional area S of the piston rod 3a, as follows: ).

[0046]

(Equation 1)

Therefore, when the external combustion type hot gas engine 1 is started,
The starting torque T required to rotate the crankshaft 10 against the force F is calculated by the following equation (2).

[0048]

(Equation 2)

Here, geometrically from FIG.

[0050]

(Equation 3)

Is as follows. Here, l is the length of the connecting rod 3b, r is the radius of rotation of the crankshaft 10,
θ indicates the crank angle of the crankshaft 10.

Therefore, equation (1) and equation (3) are added to equation (2).
As shown in FIG. 6, the starting torque T has a different value depending on the piston stroke position (the rotation stop position of the crankshaft 10) of the low-temperature side displacer piston 3 when the external combustion type hot gas engine 1 is started, as shown in FIG. . That is, when the external combustion type hot gas engine 1 is started, the crankshaft 10 is at the crank angle 0 degree position a (when the low temperature side displacer piston 3 is at the top dead center position A),
0 is a crank angle position of 30 degrees, crank shaft 10 is a crank angle position of 60 degrees, and crank shaft 10 is a crank angle position of 90 degrees c (the low-temperature side displacer piston 3 is substantially at the center between the top dead center position A and the bottom dead center position B). In the case of the position C), the starting torque T is represented by a thin solid line α in FIG.
2, the dashed line γ2, the dash-dot line δ2, and the bold solid line β2. When the external combustion type hot gas engine 1 is started, the crankshaft 10 is positioned at the crank angle 90 ° c (the low-temperature side displacer piston 3 is at the top dead center position A And the bottom dead center position B (in the case of the approximate center position C) (T = 0.7 (dimensionless amount) in FIG. 6).

Therefore, as a starting method for driving the starter motor 9 to start the external combustion type hot gas engine 1, first, the starter motor 9 is gradually driven to rotate the crankshaft 10 by a small angle at a low temperature. In order to position the displacer piston 3 at a substantially central position C between the top dead center position A and the bottom dead center position B, the crankshaft 10 is rotated by a predetermined angle and positioned at the crank angle 90 ° position c.
The positioning of the crankshaft 10 is performed, for example, by installing a magnet 51 (FIG. 2) on the crankshaft 10,
The magnetic sensor 52 may be provided in the crankcase 42 so that the positioning of the crankshaft 10 is completed when the magnetic sensor 52 detects the magnetism of the magnet 51.

Next, the low-temperature side displacer piston 3 is moved to a substantially central position C between the above-mentioned top dead center position A and bottom dead center position B.
In other words, the crankshaft 10 is moved to the position c at a crank angle of 90 degrees.
At a predetermined time (a few seconds), the leakage of the sealing material 50 of the partition wall 49 causes the pressure P1 in the intermediate temperature chambers 14 and 15 to fall.
And waits until the pressure difference ΔP between the pressure P2 and the pressure P2 in the crank chamber 47 becomes zero.

Thereafter, the starter motor 9 is continuously driven to rotate, the crankshaft 10 is continuously rotated, and the external combustion type hot gas engine 1 is started.

Therefore, according to the above embodiment, the following effects and advantages can be obtained.

The crankshaft 10 is rotated by a predetermined angle so that the low-temperature side displacer piston 3 is positioned at a substantially central position C of the piston stroke with respect to the low-temperature side cylinder 44. Next, the low-temperature side displacer piston 3 is moved to the substantially central position C of the piston stroke. And the pressure difference ΔP between the pressure P1 in the low-temperature chamber 15 and the medium-temperature chamber 14 and the pressure P2 in the crank chamber 47 is set to zero, and then the starter motor 9 is driven to rotate continuously. When the piston 3 is moved from the approximate center position C of the piston stroke to the top dead center position A side or the bottom dead center position B side, the volume change due to the ingress and egress of the piston rod 3a of the medium-temperature chamber 14 is caused by moving the low-temperature side displacer piston 3 to another position. (For example, from top dead center position A) to top dead center position A side or bottom dead center position B side Smaller than the case of moving. For this reason, the pressure P1 of the medium temperature chambers 14 and 15 and the crank chamber 4
7, the pressure difference ΔP from the pressure P2 is lower when the low-temperature side displacer piston 3 is moved from the approximate center position C of the piston stroke to the top dead center position A side or the bottom dead center position B side. Is moved from another position (for example, top dead center position A) to the top dead center position A side or the bottom dead center position B side. As a result, the starting torque T required for the rotation of the crankshaft 10 at the time of starting, which is determined based on the pressure difference ΔP, also changes the low temperature side displacer piston 3 from the approximate center position C of the piston stroke to the top dead center. When moving to the position A side or the bottom dead center position B side, the low temperature side displacer piston 3 is moved from another position (for example, the top dead center position A) to the top dead center position A side or the bottom dead center position B side. Smaller than if you let it. Therefore, the starter motor 9 that rotates the crankshaft 10 when the external combustion type hot gas engine 1 is started can be reduced in size and weight.

When the operation of the external combustion type hot gas engine 1 is started, the position of the low temperature side displacer piston 3 is positioned at substantially the center position C of the piston stroke with respect to the low temperature side cylinder 44, and the external combustion is simply stopped for a predetermined time. Since the starting torque T required at the time of starting operation of the hot gas engine 1 can be reduced, a special structure is used to reduce the starting torque T (for example, a bypass passage having an on-off valve according to the second prior art).
It is not necessary to perform the process, and there is no increase in cost.

The present invention has been described based on one embodiment, but the present invention is not limited to this. For example, in the above-described embodiment, the crankshaft 10 is positioned at the crank angle 0 degree position a and waits for a predetermined time when the external combustion type hot gas engine 1 is started up. Sometimes, the crankshaft 10 may be positioned at the crank angle 270 degree position d (FIG. 3) and wait for a predetermined time.

In the above-described embodiment, the case where the starter motor 9 is driven when the crankshaft 10 is positioned at the crank angle 90 ° position c has been described. However, the crankshaft 10 may be rotated manually, for example.

[0061]

As described above, according to the method for starting an external combustion type hot gas engine according to the present invention, the crankshaft is rotated so that the low-temperature side displacer piston is positioned substantially at the center of the piston stroke with respect to the low-temperature side cylinder. Next, the low-temperature side displacer piston is positioned at a substantially central position of the piston stroke for a predetermined time, and the difference between the internal pressure of the working chamber and the crank chamber defined by the low-temperature cylinder and the low-temperature side displacer piston is set to zero, Thereafter, the starter motor is driven, so that when the external combustion type hot gas engine is started, the change in volume of the working chamber defined by the low temperature side cylinder and the low temperature side displacer piston can be set to the minimum, and as a result, the external combustion type Since the starting torque of the hot gas engine can be minimized, a special structure is used to reduce the starting torque. Succoth without downsizing the starting motor, it lighter.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a cooling / heating water circuit of a heat pump type air conditioner equipped with an external combustion type hot gas engine which implements an embodiment of a method for starting an external combustion type hot gas engine according to the present invention. .

FIG. 2 is a side sectional view showing the external combustion type hot gas engine of FIGS. 1 and 2;

FIG. 3 is a schematic diagram conceptually showing a low-temperature side displacer piston, a crankshaft, and the like of the external combustion type hot gas engine of FIGS. 1 and 2;

FIG. 4 is a schematic diagram for obtaining a starting torque required to rotate the crankshaft of FIGS. 1 and 2;

FIG. 5 is a graph showing a pressure difference between a low temperature chamber and a crank chamber in FIGS. 1 and 2;

FIG. 6 is a graph showing a starting torque required to rotate the crankshaft of FIGS. 1 and 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 External combustion type hot gas engine 2 High temperature side displacer piston 3 Low temperature side displacer piston 2a, 3a Piston rod 9 Starter motor 10 Crankshaft 14 Medium temperature room 15 Low temperature room 43 High temperature side cylinder 44 Low temperature side cylinder 47 Crank room P1, P2 Pressure ΔP Pressure difference A Top dead center position B Bottom dead center position C Approximately center position between top dead center position and bottom dead center position

Claims (1)

[Claims] A high temperature side displacer piston is reciprocally accommodated in a high temperature side cylinder, and a low temperature side displacer piston is reciprocally accommodated in a low temperature side cylinder. Both of these displacer pistons are arranged in a crank chamber via a piston rod. The piston rod on the low-temperature side displacer piston connected to the provided crankshaft is formed to have a larger diameter than the piston rod on the high-temperature side displacer piston, and drives a starter motor connected to the crankshaft. In the method for starting an external combustion type hot gas engine which starts operation by causing the crankshaft to rotate, the low-temperature side displacer piston is rotated to a position substantially at the center of a piston stroke with respect to the low-temperature side cylinder. Side display The Sapisuton positioned a predetermined time to the approximate center of the piston stroke,
An external-combustion hot gas engine, wherein the difference between the internal pressure of the working chamber defined by the low-temperature side cylinder and the low-temperature side displacer piston and the internal pressure of the crank chamber is set to zero, and then the starter motor is driven. How to start.