JP3363678B2 - Operation control device for heat source unit and operation method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for a Vermier cycle heat source machine having a combustor and an operation method thereof.

[0002]

2. Description of the Related Art Generally, there is known a heating / cooling device that uses a Vermier cycle heat source machine having a combustor to produce cold / hot water, and uses this cold / hot water to air-condition a room.
This type of air conditioner has the advantage of being an environmentally friendly air conditioner because it can air-condition the room without using a refrigerant containing CFCs.

By the way, when the conventional Vermier cycle heat source machine is operated, the combustion amount of the combustor is controlled and operated.
However, the combustion amount of the combustor cannot be reduced to any extent, and the combustor is stopped in an operation (hereinafter, referred to as “light load operation”) in a state where a combustion amount equal to or less than the minimum combustible amount is desired. It is necessary to stop the operation of the Vermier cycle heat source machine itself when the combustion machine is stopped. When the operation of the Vermier cycle heat source machine itself is stopped, the air conditioning is not performed, and when the operation is required again to meet the air conditioning load, the Vermier cycle heat source machine is started.

[0004]

However, as described above, at the time of light load operation, it is necessary to stop or operate the Vermier cycle heat source machine as long as it is continued. Driving has a problem that the number of starts and stops increases. The Vermier cycle heat source machine has a large heat capacity in the combustion system, poor thermal response at start and stop, long transient fluctuation time, and poor responsiveness. There are many unfavorable points, such as the outlet temperature of hot water pulsates greatly, and the start and stop greatly affect the life of the Vermier cycle heat source machine,
Conventionally, it has been technically requested to reduce the number of start and stop of the Vermier cycle heat source machine.

Therefore, an object of the present invention is to provide an operation control device for a Vermier cycle heat source device and a method for operating the same, which can reduce the start and stop of the Vermier cycle heat source device even during light load operation. It is in.

[0006]

According to the invention as set forth in claim 1, in an operation control device of a Vermier cycle heat source machine having a combustor, a combustion amount equal to or less than a minimum combustion amount for continuously operating the combustor. Is required to temporarily stop the operation of the combustor, the operation of the combustor stopped by the temporary operation stop means during the light load operation, the light load operation It is characterized in that it is provided with operation starting / stopping means for repeatedly starting and stopping under the condition of being in a state.

According to the invention described in claim 2, in a method of operating a Vermier cycle heat source machine having a combustor,
During a light load operation in which a combustion amount equal to or less than the minimum combustion amount for continuously operating the combustor is required, the operation of the combustor is temporarily stopped, and the operation of the combustor is temporarily stopped during the light load operation. Is repeatedly started and stopped under the condition that the operating state is a light load operating state.

According to these inventions, the combustor is temporarily stopped during a light load operation in which a combustion amount smaller than the minimum combustion amount is required. However, since the heat capacity of the combustion system is large, the engine continues operating without stopping. Therefore, the combustion is restarted while the operation is continued. Then, after burning for a certain period of time, it is stopped again. By repeating this, the operation of the combustion amount required on average is continued.

This is because the Vermier cycle heat source machine has a large heat capacity and has a large delay time such that the heat source machine does not stop even after a few minutes after the combustion of the combustor is stopped. It will be possible.

At this time, it is necessary to start and stop the combustion device.
This is equivalent to starting and stopping the entire conventional engine, and the combustion system has the same number of starting and stopping operations as the conventional one, but the number of starting and stopping operations of other parts is significantly reduced. For starting and stopping the combustion system, most parts can be operated continuously by keeping the blower system and the ignition system in the operating state and opening and closing only the fuel valve. Since the valve can be operated with the same number of starts and stops as before, the life is greatly improved. A general method is to start and stop the engine at a certain temperature or lower, and restart the engine at another certain temperature. However, in such a system, pulsation occurs in the temperature of the cold / warm water output. However, by adopting this method, an output with less pulsation can be output and the temperature pulsation of the cold and warm water can be suppressed to a small level.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a Vermier cycle heat source machine (hereinafter referred to as "external combustion type engine"), which is provided in the cylinder inner space on the head side of the displacer piston 3 which moves up and down in the high temperature side cylinder 2. A high-temperature working gas (for example, helium gas of about 700 K to 1000 K) flows in and out, and a medium temperature working gas (for example, 300 K to 400 K) flows in and out of the cylinder inner space on the other side. Reference numeral 4 denotes a low temperature side cylinder having a displacer piston 5, and a working gas at a low temperature side (for example, 200K to 300K) flows into and out of a cylinder inner space on the head side of the displacer piston 5 that moves left and right in the cylinder. The working gas at an intermediate temperature level flows in and out of the inner space of the cylinder on the other side.

Reference numeral 6 is a heater tube for heating a working gas at a high temperature level, and a fin 7 is provided outside the heater tube. The heater tube 6 is heated by the combustion gas of a combustor (hereinafter referred to as “burner”) 36. Reference numeral 8 is a regenerator, and a working gas of a high temperature level (hereinafter referred to as "high temperature gas") flows in and out through an upper opening thereof, and a working gas of a middle temperature level flows in and out through a lower opening thereof. Reference numerals 9 and 10 denote heat radiating heat exchangers for radiating the working gas of medium temperature level (hereinafter, referred to as "medium temperature gas"). Reference numeral 11 denotes a regenerator, through which a medium temperature gas flows in and out through a left side opening thereof, and a working gas of a low temperature level (hereinafter referred to as “low temperature gas”) flows in and out through a right side opening thereof. Further, 12 is a heat exchanger for heat absorption. Reference numeral 13 is a tube through which a low temperature gas flows, and 14 is a tube through which a medium temperature gas flows.

Reference numeral 15 denotes a radiator on the heating load side, which is connected to the heat radiating heat exchangers 9 and 10 by a hot water pipe line 16.
Reference numeral 17 denotes a cooling load side cooler, which is connected to a heat absorbing heat exchanger 12 by a cold water pipe line 18.

Reference numerals 19 and 20 denote connecting rods connected to piston rods 21 and 22 of the displacer pistons 3 and 5, respectively, and these rods are connected to a crank 23 so as to rotate with a constant phase angle. . An electric motor 28 as a starter is connected to the rotary shaft 24 of the crank 23. And
When the rotary shaft 24 rotates clockwise as shown by the arrow in the figure, the displacer pistons 3 and 5 move with a certain phase difference. The diameter of the piston rod 22 of the displacer piston 5 is equal to that of the piston rod 21 of the displacer piston 3.
It is made larger than that. Further, 25 is a crankcase, and the case 15 and the cylinders 2 and 4 are partitioned by partition walls 26 and 17, respectively.

Next, the driving operation will be described.

At the time of start-up, the electric motor 28 is operated as a starter, whereby the rotating shaft 24 starts to rotate and the burner 36 starts to burn, so that the working gas is first heated. When the rotary shaft 24 starts to rotate, the displacer pistons 3 and 5 start to slide in the cylinders 2 and 4 with a constant phase difference, and the volumes of the head side of these cylinders 2 and 4 and the space on the opposite side thereof. 2 to 5, the working gas reciprocates in these spaces and is heated in the heater tube 6 while being radiated in the heat radiating heat exchangers 9 and 10. By performing the above, as shown in FIG. 6, the cyclic expansion and contraction of the working gas in the space where the volume changes,
The cyclic pressure change of the working gas in the external combustion engine 1 is repeated, and thereby the cold / hot water output is generated. That is, the heat release of the working gas in the heat releasing heat exchangers 9 and 10 generates hot water output, and the heat absorbing heat exchanger is accompanied by the cyclic expansion of the working gas in the variable space on the head side of the low temperature side cylinder 4. Cold water output is generated by the action of pumping heat through 12.

2 to 5 show a quarter of the rotary shaft 24.
It is an operation explanatory view of the external combustion type engine 1 showing the positional relationship of the displacer pistons 3 and 5 for each rotation (90 °), and the arrows in the figure indicate the sliding direction and rotation of the displacer pistons 3 and 5. The rotation direction of the shaft 24 is shown. Further, FIG. 6 is a diagram showing a periodic pressure change of the working gas in one rotation of the rotary shaft 24 and a volume change of the space on the head side of the cylinder and the space on the opposite side thereof, and the solid line in the figure represents the cylinder. 2 of the head side volume change of (V _H), the broken line, the cylinder 4 head side volume change of (V _C), the chain line represents opposite volume change in these cylinder head (V _M), 2 points The chain line represents the pressure change (P _X ) of the working gas.

After the external combustion engine 1 is started, the above-mentioned operation is repeated and gradually shifts to a steady state, and the working gas in the space on the cylinder head side becomes a high temperature gas of a desired high temperature level, while The working gas in the space on the head side of the cylinder 4 becomes a low temperature gas having a desired low temperature level, and the working gas in the space on the side opposite to the cylinder bed becomes a medium temperature gas having a desired middle temperature level.

Along with this, the power generated by the external combustion engine 1 gradually increases, and this and the load power are balanced in a steady state, so that the external combustion engine 1 can obtain a rated cold / hot water output. Become.

Taking the cooling operation as an example, when the air conditioning load decreases, the combustion amount of the burner 36 of the external combustion engine 1 decreases. And the air conditioning load is further reduced,
When a light load state in which a combustion amount equal to or less than the minimum combustion amount required for the operation of the burner 36 is required, the combustion of the burner 36 is completely stopped.

According to this embodiment, when the air conditioning load reaches a light load that requires a combustion amount equal to or less than the minimum combustion amount required to continuously operate the burner 36, as shown in FIG. Temporarily stop operation of 36 (OFF)
Let When this is stopped (OFF), as shown in FIG. 7b, the temperature of the cold water output from the external combustion engine 1 gradually rises. However, since the heat capacity of the external combustion engine 1 is large, the gradient of the temperature drop is gentle as shown in the figure.

The feature of this embodiment is that when the air conditioning load is in the light load state, the operation of the burner 36 is not stopped (OFF), and as shown in FIG. It is to repeat (ON / OFF) (duty operation control). By repeating this start and stop, as shown in FIG. 7b, the temperature of the chilled water output from the external combustion engine 1 is maintained at a predetermined level, so that the operation of the external combustion engine 1 is not stopped and is kept as it is. It is possible to continue operation.

FIG. 9 shows an ON / OFF operation control system. With this control method (conventional), when the light load state is reached, the operation of the burner 36 is stopped (OFF) as shown in FIG. 9a, and the burner 36 is operated while the light load state is continued. It remains stopped (OFF). Then, even if the air-conditioning load demand increases and the burner 36 is operated (ON) again in response to it, since the heat capacity of the external combustion engine 1 is large, the temperature of the chilled water immediately drops as shown in FIG. 9b. Instead, the temperature overshoots too much and rises too much.

In the operating method according to this embodiment, the cooling operation will be described as an example, with reference to FIG.
First, the cold water temperature (air conditioning load) of the cold water output from the external combustion engine 1 is detected (S1), and the required combustion amount in the burner 36 is calculated from this cold water temperature by PID calculation (S2). It is determined whether or not the required combustion amount calculated in S2 is equal to or greater than the minimum combustion amount required to operate the burner 36 (S3). If the determination is equal to or greater than the minimum combustion amount, the burner is determined according to the required combustion amount. 36 has a duty ratio of 100
% Is continuously operated (S4). If the judgment is equal to or less than the minimum combustion amount, as described above, start / stop of the burner 36 (ON / O
FF) is repeated at the minimum combustion amount to perform duty operation control (S5).

In step S5, the duty ratio (ON / OFF time interval) in the duty operation control is calculated based on, for example, ON / OFF time interval = (required combustion amount / minimum combustion amount). To be done.

According to this embodiment, as is clear from FIG. 7b, in the light load operation state, only the start / stop (ON / OFF) of the burner 36 is stopped without stopping the entire external combustion engine 1. By repeating (duty operation control), the temperature overshoot shown in FIG. 9b can be almost avoided.

It is necessary to start / stop (ON / OFF) the burner 36, and the number of times of starting / stopping is the same as the number of starts / stops of the conventional type, but the number of starting / stopping of other parts of the external combustion engine 1 is significantly large. The burner 36 starts and stops (ON / OF
In F), most of the parts can be operated continuously by adding a device such as opening and closing only the fuel valve while leaving the blower system and the ignition system in the operating state. Moreover, the number of times of starting and stopping the fuel valve may be at most the same as the number of times of starting and stopping, which is the same as the conventional one, so that the life of the external combustion engine 1 can be significantly improved. The temperature pulsation of the cold / hot water output from the external combustion engine 1 occurs with the start / stop of the external combustion engine 1. According to this, since the external combustion engine 1 is left unoperated, the temperature of the cold / hot water This has the effect of suppressing pulsation to a small level.

[0029]

EFFECTS OF THE INVENTION According to these inventions, during a light load operation in which a combustion amount smaller than the minimum combustion amount is required,
If the combustor is temporarily stopped and the light load operation is continued, the operation of the combustor is restarted after a predetermined time, and again after burning for a certain time, it is stopped again, and when the light load operation is further continued, it is restarted. Since the operation is started and the operation is repeated to continue the operation of the combustion amount required on average, the number of times of starting and stopping the other parts of the heat source machine other than the combustor can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an operation control device for a Vermier cycle heat source machine and an operation method thereof according to the present invention.

FIG. 2 is a diagram showing an operation of a Vermier cycle heat source machine.

FIG. 3 is a diagram showing an operation of a Vermier cycle heat source machine.

FIG. 4 is a diagram showing an operation of a Vermier cycle heat source machine.

FIG. 5 is a diagram showing an operation of the Vermier cycle heat source machine.

FIG. 6 is a diagram showing a periodic pressure change of the working gas and a volume change of the space on the cylinder head side and the space on the opposite side in one rotation of the rotating shaft of the Vermier cycle heat source machine.

FIG. 7 is a diagram showing an embodiment of a method for operating a Vermier cycle heat source machine.

FIG. 8 is a flowchart of the same.

FIG. 9 is a view corresponding to FIG. 7 of the related art.

[Explanation of symbols]

1 Vermier cycle heat source machine 9,10 Heat dissipation heat exchanger 12 Endothermic heat exchanger 15 radiator 17 Cooler 36 Combustor (burner)

Continuation of front page (56) Reference JP-A-1-137164 (JP, A) JP-A-7-55276 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 9 / 14 510 F02G 1/047

Claims (2)

(57) [Claims] 1. An operation control device for a Vermier cycle heat source machine having a combustor, wherein the combustor is operated during a light load operation in which a combustion amount equal to or less than a minimum combustion amount for continuously operating the combustor is required. Starting and stopping the temporary operation stopping means for temporarily stopping and the operation of the combustor stopped by the temporary operation stopping means during the light load operation, on condition that the operating state is the light load operating state. An operation control device for a heat source machine, comprising: 2. A method of operating a Vermier cycle heat source machine having a combustor, wherein the combustor is temporarily operated during a light load operation in which a combustion amount equal to or less than a minimum combustion amount for continuously operating the combustor is required. The method for operating a heat source machine, wherein the operation of the combustor that has been temporarily stopped during the light load operation is repeatedly started and stopped under the condition of the light load operation state.