Patent Description:
As such an engine system, an engine-driven heat pump system (hereinafter may be referred to as "GHP") has been known (for example, see Patent Literature <NUM> (PTL <NUM>)). The heat pump system includes a heat pump circuit functioning as the system main portion and configured to transfer heat through circulation of refrigerant by a compressor, and the compressor is driven by the shaft power of the engine. Patent Literature <NUM> (PTL <NUM>) discloses an apparatus controlling the air-fuel ratio in response to the stable output of an oxygen sensor. Patent Literature <NUM> (PTL <NUM>) discloses an engine driven heat pump including an outdoor fan and an engine cooling water pump, each of which is driven by the generation power of a generator. Patent Literature <NUM> (PTL <NUM>) discloses an electric apparatus storing data to be backed up when an abnormality occurs in a power source. Patent Literature <NUM> (PTL <NUM>) discloses a fuel system for supplying fuel to a vehicle compression ignition engine and of the kind comprising a pumping apparatus including a high pressure fuel pump driven in synchronism with the associated engine. <CIT> discloses a genset engine connectable to commercial power system which is supplied with electricity from the commercial power system for the engine start-up.

Such a known engine system has the following possible disadvantage: if a failure such as an electric leakage and a malfunction occurs in the power source unit, operation of both of the system main portion and the engine cannot be normally controlled, and therefore, the situation cannot be quickly dealt with, for example, by stopping the engine.

In view of the above circumstances, a main object of the present invention is to provide a technique which makes it possible to quickly deal with occurrence of a failure in a power source unit of an engine system, the engine system including: an engine configured to output shaft power by burning fuel; and a system main portion configured to operate using the shaft power of the engine, the engine system further including: an operation controlling unit; and the power source unit configured to supply operating power to the operation controlling unit.

In a first aspect of the present invention, an engine system as defined by the features of claim <NUM> includes: an engine configured to output shaft power by burning fuel; and a system main portion configured to operate using the shaft power of the engine, the engine system further including:
an operation controlling unit; and a power source unit configured to convert commercial power to operating power and to supply the operating power to the operation controlling unit.

The power source unit includes: a system main portion-side power source unit configured to supply operating power for controlling operation of the system main portion; and an engine-side power source unit configured to supply operating power for controlling operation of the engine, the system main portion-side power source unit and the engine-side power source unit being provided in a parallel manner.

In this aspect, if a failure such as an electric leakage and a malfunction occurs in the system main portion-side power source unit configured to supply operating power for controlling the operation of the system main portion, it is possible to keep the engine-side power source unit in a normal state, and to reliably supply operating power for controlling the operation of the engine. This makes it possible to control the operation of the engine, to cause the engine system to transition into an engine-stopped state or the like.

Meanwhile, if a failure such as an electric leakage and a malfunction occurs in the engine-side power source unit configured to supply operating power for controlling the operation of the engine, it is possible to keep the system main portion-side power source unit in a normal state, and to reliably supply operating power for controlling the operation of the system main portion. This makes it possible to control the operation of the system main portion.

Thus, the present invention can provide an engine system capable of dealing with occurrence of a failure in the power source unit.

According to the present invention, the operation controlling unit includes a system main portion controlling unit and an engine controlling unit which are provided individually and separately, the system main portion controlling unit configured to receive operating power from the system main portion-side power source unit and to control operation of the system main portion, the engine controlling unit configured to receive operating power from the engine-side power source unit and to control operation of the engine.

In this aspect, the system main portion controlling unit and the engine controlling unit, each functioning as the operation controlling unit, are provided individually and separately. Because of this, if a failure occurs in one of these units, it is possible to keep the other unit in a normal state without being affected by the failure.

In a third aspect of the present invention, the system main portion controlling unit and the engine controlling unit are configured to be communicable with each other; and
each of the system main portion controlling unit and the engine controlling unit is configured to perform an engine stop process of stopping the engine when detecting an error in communication with the other.

In this aspect, each of the system main portion controlling unit and the engine controlling unit can detect, by the function of communicating with the other, that a failure such as an electric leakage and a malfunction occurs on the other side. Each of the system main portion controlling unit and the engine controlling unit is configured to perform the engine stop process to reliably stop the engine when detecting such an error in the communication with the other.

In the fourth aspect of the present invention, the engine system further includes a starter transformer configured to step down commercial power and to supply the stepped down power to a starter of the engine, and
the engine-side power source unit is configured to generate operating power using the power stepped down by the starter transformer.

In this aspect, it is possible to supply the power stepped down by the starter transformer to the engine-side power source unit, by effectively using the starter transformer of the engine. Due to this, a transformer configured to step down supplied power to desired operating power does not have to be provided in the engine-side power source unit, or such a transformer can be simplified if provided, leading to efficient generation of operating power.

In a fifth aspect of the present invention, the engine-side power source unit is configured so that one or more voltage changing units configured to change voltage of operating power are attachable to and detachable from the engine-side power source unit.

In this aspect, one or more voltage changing units are attachable to and detachable from the engine-side power source unit. This makes it possible to generate operating power of a required voltage by changing the voltage changing unit(s) as needed. Furthermore, the engine-side power source unit may be configured so that two or more voltage changing units are attachable to and detachable from the engine-side power source unit, so as to generate operating power of various voltages.

In a sixth aspect of the present invention, the engine system further includes a fuel shutoff valve capable of shutting off supply of fuel to the engine, and
the operation controlling unit is configured to be capable of performing a fuel shutoff process of actuating the fuel shutoff valve to stop the engine in control of the operation of the system main portion.

In this aspect, when a failure occurs in the engine-side power source unit configured to supply operating power for controlling the operation of the engine, for example, it is possible to shut off the supply of fuel to the engine by performing the fuel shutoff process in the control of operation of the system main portion by the operation controlling unit, and thereby to reliably stop the engine.

[<FIG>] A schematic configuration diagram of an engine system related to an embodiment.

An embodiment of the present invention will be described with reference to the drawing.

An engine system <NUM> shown in <FIG> is structured, for example, as a so-called engine-driven heat pump system (GHP) configured so that a compressor <NUM> of a heat pump circuit (not illustrated) in which refrigerant circulates is driven by an engine <NUM>. The engine system <NUM> is provided with: the engine <NUM> configured to output shaft power by burning fuel G; and a system main portion <NUM> configured to operate using the shaft power of the engine <NUM>. The system main portion <NUM> includes the compressor <NUM> and the like. The engine system <NUM> is further provided with: an operation controlling unit A configured to control operation; and a power source unit B. The power source unit B is configured to convert commercial power to operating power, and to supply the operating power to the operation controlling unit A. More specifically, the power source unit B is configured to convert alternating-current (AC) commercial power supplied from a commercial power source <NUM> to direct-current (DC) operating power through an AC-DC converter or the like, and to supply the operating power to the operation controlling unit A. It should be noted that no limitation is needed for the engine type, the fuel, and the like of the engine <NUM>. For example, a reciprocating engine, gas turbine engine, or the like fueled by city gas can be used as the engine <NUM>.

The operation controlling unit A includes: a main controlling unit <NUM> (an example of a system main portion controlling unit) configured to control operation of the system main portion <NUM>; and an engine controlling unit <NUM> configured to control operation of the engine <NUM>. The main controlling unit <NUM> and the engine controlling unit <NUM> are provided individually and separately.

Specifically, the main controlling unit <NUM> is installed in a main controller <NUM>. The main controlling unit <NUM> is configured to control operation of a fuel shutoff valve <NUM> and other electric devices provided on a system main portion <NUM> side. Meanwhile, the engine controlling unit <NUM> is installed in an engine controller <NUM> which is different from the main controller <NUM>. The engine controlling unit <NUM> is configured to control operation of a cooling water pump, an ignition device, and other electric devices provided on an engine <NUM> side.

The power source unit B configured to supply operating power to the operation controlling unit A includes: a main power source unit <NUM> (an example of a system main portion-side power source unit) configured to supply operating power for controlling the operation of the system main portion <NUM>; and an engine-side power source unit <NUM> configured to supply operating power for controlling the operation of the engine <NUM>. The main power source unit <NUM> and the engine-side power source unit <NUM> are provided in a parallel manner. The main power source unit <NUM> is configured to supply operating power for controlling the operation of the system main portion <NUM> to the main controller <NUM> in which the main controlling unit <NUM> is installed. The engine-side power source unit <NUM> is configured to supply operating power for controlling the operation of the engine <NUM> to the engine controller <NUM> in which the engine controlling unit <NUM> is installed. That is, (i) a main-side power supply board having the main power source unit <NUM> and (ii) an engine-side power supply board having the engine-side power source unit <NUM> are provided as power supply boards in the engine system <NUM> individually and separately.

The system main portion <NUM> is provided with the fuel shutoff valve <NUM> capable of shutting off the supply of the fuel G to the engine <NUM>. The main controlling unit <NUM> is configured to be capable of performing a fuel shutoff process (an example of an engine stop process) of actuating the fuel shutoff valve <NUM> to force the engine <NUM> to stop.

Meanwhile, the engine controlling unit <NUM> is configured to be capable of performing an ignition stop process (an example of the engine stop process) of, for example, stopping application of voltage to a spark plug (not illustrated) of the engine <NUM> to force the engine <NUM> to stop.

Furthermore, the main controlling unit <NUM> and the engine controlling unit <NUM> are configured to be communicable with each other through a communication unit <NUM> installed in the main controller <NUM> and a communication unit <NUM> installed in the engine controller <NUM>.

When the main controlling unit <NUM> communicates with the engine controlling unit <NUM> through the above-mentioned communication units <NUM> and <NUM> and then detects an error in the communication with the engine controlling unit <NUM>, the main controlling unit <NUM> determines that a failure such as an electric leakage and a malfunction occurs in the engine controlling unit <NUM> or in the engine-side power source unit <NUM> configured to supply operating power to the engine controlling unit <NUM>. When determining that a failure occurs on an engine controlling unit <NUM> side as above, the main controlling unit <NUM> stops the engine <NUM> by performing the above-described fuel shutoff process.

Meanwhile, when the engine controlling unit <NUM> communicates with the main controlling unit <NUM> through the above-mentioned communication units <NUM> and <NUM> and then detects an error in the communication with the main controlling unit <NUM>, the engine controlling unit <NUM> determines that a failure such as an electric leakage and a malfunction occurs in the main controlling unit <NUM> or in the main power source unit <NUM> configured to supply operating power to the main controlling unit <NUM>. When determining that a failure occurs on a main controlling unit <NUM> side as above, the engine controlling unit <NUM> stops the engine <NUM> by performing the above-described ignition stop process.

The engine-side power source unit <NUM> is configured to supply operating power for controlling the operation of the engine <NUM> to the engine controlling unit <NUM>, and in addition, to supply operating power for controlling the operation of the system main portion <NUM> to the main controlling unit <NUM>. That is, to the main controller <NUM> in which the main controlling unit <NUM> is installed, operating power is supplied not only from the main power source unit <NUM> but also from the engine-side power source unit <NUM>. Due to this, if a failure such as an electric leakage and a malfunction occurs in either one of the main power source unit <NUM> and the engine-side power source unit <NUM>, i.e., in one of the units functioning as the power source unit B, operating power is supplied from the other units functioning as the power source unit B, and this allows the main controlling unit <NUM> to operate normally. This further allows the main controlling unit <NUM> to perform the above-described fuel shutoff process, to reliably stop the engine <NUM>.

The engine system <NUM> is provided with a starter transformer <NUM> configured to step down the commercial power supplied from the commercial power source <NUM> and to supply the power to a starter <NUM> of the engine <NUM>.

The engine-side power source unit <NUM> is configured to generate operating power using the power stepped down by the starter transformer <NUM>. Consequently, the power stepped down by the starter transformer <NUM> to a voltage of on the order of several tens of volts is supplied to the engine-side power source unit <NUM>. Due to this, a transformer configured to step down supplied power to desired operating power does not have to be provided in the engine-side power source unit <NUM>, or such a transformer can be simplified if provided, leading to efficient generation of operating power.

AC commercial power is directly supplied to the main power source unit <NUM> from the commercial power source <NUM> via an earth leakage circuit breaker <NUM>. The main power source unit <NUM> may incorporate a transformer configured to step down the commercial power to <NUM> V, for example, which is the supply voltage of general electric devices. In this case, the main power source unit <NUM> supplies the operating power stepped down by the transformer to the main controlling unit <NUM> and to electric devices such as the fuel shutoff valve <NUM>, which are on the system main portion <NUM> side and are controlled by the main controlling unit <NUM>.

Meanwhile, the engine-side power source unit <NUM> is configured so that a voltage changing unit <NUM> is attachable to and detachable from the engine-side power source unit <NUM>. The voltage changing unit <NUM> is structured by: a regulator configured to change the voltage of the power stepped down by the starter transformer <NUM>; and the like. The voltage changing unit <NUM> can be attached, as an external device, to the engine-side power supply board having the engine-side power source unit <NUM>. This enables the engine-side power source unit <NUM> to generate operating power of a voltage other than the general supply voltage. Furthermore, although not shown in the figure, two or more voltage changing units <NUM> may be attached at the same time. This makes it possible to efficiently generate operating power of various voltages.

Claim 1:
An engine system (<NUM>) comprising:
an engine (<NUM>) configured to output shaft power by burning fuel; and a system main portion (<NUM>) configured to operate using the shaft power of the engine (<NUM>), the engine system (<NUM>) further comprising:
an operation controlling unit (A); and a power source unit (B) configured to convert commercial electric power to operating electric power and to supply the operating electric power to the operation controlling unit (A), wherein
the system main portion (<NUM>) comprises a fuel shutoff valve (<NUM>) capable of shutting off supply of fuel to the engine (<NUM>), and
wherein the power source unit (B) comprises: a system main portion-side power source unit (<NUM>) configured to supply operating power for controlling operation of the system main portion (<NUM>) ; and an engine-side power source unit (<NUM>) configured to supply operating power for controlling operation of the engine (<NUM>), the system main portion-side power source unit (<NUM>) and the engine-side power source unit (<NUM>) being provided in a parallel manner, characterized in that
the operation controlling unit (A) comprises a system main portion controlling unit (<NUM>) and an engine controlling unit (<NUM>) which are provided individually and separately, the system main portion controlling unit (<NUM>) configured to receive operating power from the system main portion-side power source unit (<NUM>) and to control operation of the system main portion (<NUM>), the engine controlling unit (<NUM>) configured to receive operating power from the engine-side power source unit (<NUM>) and to control operation of the engine (<NUM>).