JPH11351057A - Hybrid energy supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid cogeneration system that utilizes fuel effectively unlike an individual operation of an existent general-purpose engine generator. SOLUTION: An internal-combustion engine 6 is arranged as a main engine, to which a generator 9 and an air-conditioning compressor 7 are connected, and a solar generator 11 converts solar energy usable during the day into the electric power that charges a storage battery 12. The engine 6 is driven only at the operating point that provides output conditions with high conversion efficiency into rotational energy, and the generated power is DC-converted before charging the storage battery 12. To the DC circuit, an inverter converter 13 is connected, for AC conversion, which is in turn connected to a power-system distribution line 15 and a power-load distribution line 17. Hot water 5 after engine cooling is used as a heat source of a heating/hot-water-supply system. On the basis of the measurements of required electric energy and heat flow, an energy supplying control processor 18 issues commands to select and execute an operating mode with continuous maximum energy conversion/utilization efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy supply system having an internal combustion engine (hereinafter referred to as an "engine") as a main engine and comprising a plurality of energy supply / accumulation sources. The present invention relates to a device for appropriately switching modes and converting and supplying heat and electric energy with high fuel use efficiency in terms of overall efficiency.

[0002]

2. Description of the Related Art A device for generating electric energy by an engine has conventionally been used as a general-purpose engine generator in an area where a power distribution line of a power company cannot be used. Although the engine-based power generator is a well-known technology today, the following items are to be improved with respect to the conventional technical field. (B) The conventional system does not consider the current energy situation, carbon dioxide emission regulations, nitrogen oxide emissions, and the like from the beginning. (B) Research into improving the characteristics of engines to improve fuel use efficiency is being conducted today. However, when the generator is operated at low output, the efficiency is substantially deteriorated. (C) It is necessary to adjust the fuel for controlling the output of the engine according to the degree of the power demand, and a control device for that is indispensable. (D) The engine cooling water is warmed, but the thermal energy is released to the atmosphere by the engine radiator without being used effectively, so that the fuel utilization efficiency is extremely poor.

[0003]

With the development of the performance improvement of the conventional engine power generator with respect to the engine, attempts to solve the problem of energy saving and environmental preservation are technically limited. Therefore, the present invention has been invented in order to create a device for supplying heat and electric energy with high fuel use efficiency as much as possible in consideration of environmental measures such as global warming and exhaust gas regulations.

[0004]

Means for Solving the Problems Now, the configuration will be described. (A) Hot water obtained by cooling an internal combustion engine (hereinafter referred to as an engine) is used as a heat source for heating and hot water supply equipment. (B) A generator and an air conditioner compressor are installed on the output shaft of the engine.
The air is converted to direct current, and the air is cooled by the compressor. (One of normal fuel oil, kerosene, gasoline oil and various fuel gases is selectively used as the engine fuel.) (C) The DC voltage is converted to a desired AC by a bidirectional pwm inverter converter (13). You. Where bidirectional p
The wm inverter / converter can have the same function by using independent inverter devices and converter devices. (D) The converted AC power is connected to the power load distribution line (17) through a watt hour meter (16) and the power system distribution line (15) through an electromagnetic switch (14). (E) A storage battery (12) and a solar power generator (11) are connected to the DC voltage circuit. Since the storage battery has the function of storing and releasing electricity in the form of electric energy, it stores surplus power generated by the engine generator and surplus power at midnight of the power company, and stores and stores it according to the demand of the power system and power load.
Has the ability to release. The device is operated as described above.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. An engine is operated only at an operating point under an engine output condition with high conversion efficiency to rotational energy, and a generator connected to the engine output shaft is also used. Use a rating that is designed to maximize efficiency at that operating point. The generated power is converted to DC by a rectifier, and then guided to a bidirectional PWM inverter / converter to be converted to AC. A storage battery for storing power is connected to the DC circuit part on the way.
(However, a rectifier is unnecessary if the generator is a DC machine.) Separately, power is generated by a solar power generator and guided to a DC circuit. The AC converted into the same frequency as the power system (15) by the inverter is connected to both the power load distribution line and the power system distribution line. A power meter (16) is attached to the power load wiring to detect the degree of power demand, and the load power in use is measured and monitored. While monitoring the energy demands required by this system with a heating / hot water supply temperature flow meter and a watt-hour meter (16), the system controller (18) ensures the following to maximize the energy conversion and utilization efficiency. Operation mode is selected and executed. Mode in which power demand is mild The engine does not start, but is converted to AC by the inverter through the storage battery and supplied with power. No impact on the environment. Charging mode When the storage battery continues to be discharged and reaches a discharge limit value, the engine starts, charges the storage battery, and supplies power to the power load in the form of electric energy through the inverter. Mode where power demand is moderate When the engine starts, the generator generates power. When the generated power exceeds the power demand, the power is stored in the storage battery.
In this case, the hot water of the engine is guided to a heating / hot water supply facility and used. Since hot water is also used, fuel efficiency is improved. Mode of severe power demand Even when the engine is running, the power is always insufficient, and power is supplied from the power system. In this case, the engine hot water can be used for hot water supply equipment. Mode in which only the heating and hot water supply is used as a heat source The engine is operated and hot water is guided to the heating and hot water supply.
At this time, the engine output is charged to the storage battery through the generator. When the battery is fully charged, it is converted to AC by an inverter and passed to the power system. If the hot water supply capacity is insufficient, a normal electric boiler is operated if necessary. Solar cell mode When solar energy is available during the day, power is always generated regardless of power demand, and electric energy is charged to the storage battery. Midnight mode The midnight surplus power of the power company is supplied from the power distribution line,
Power is stored in the storage battery through a two-sided inverter / converter. If it is possible to buy and sell power, it is delivered at the time of the first power demand in the daytime part of the power system. Thus, the greatest feature of this system is that it uses the engine either at maximum efficiency or shuts down in response to heat and power demands, thus saving fuel consumption compared to conventional general-purpose engine generator systems. A highly efficient energy source can be configured. This system can be used as an ordinary household or as a medium- or small-scale energy source.

[0006]

As described in the above embodiments, the engine is always operated only at the output operating point having the maximum efficiency according to the power demand, so that the fuel cost can be reduced and the global environmental problems such as carbon dioxide emission can be improved. Can greatly contribute. Also, the use of a storage battery brings about the effective use of surplus power at night, can increase the power generation efficiency accompanying the energy supply of the power company, and also has the effect of contributing to the improvement of global environmental problems.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a main part of the present invention.

[Explanation of symbols] is the engine cooling water, the engine start switch, the engine fuel inlet, the temperature flow meter for heating and hot water supply, the engine hot water (hot water supply equipment), the engine, the compressor for the air conditioner, the engine rotating axle, and the generator. Is a rectifier. {11} is a photovoltaic generator. <12> is a storage battery. <13> is a bidirectional pwm inverter / converter. <14> is an electromagnetic switch. <15> is a power system distribution line. ▼ is a power load distribution line. ▲ 18 is a system controller (Energy Suppp).
lying Control Processor)

Claims (1)

[Claims] (1) A heat source, power supply and power storage device comprising an internal combustion engine, a generator, a solar power generator and a storage battery. (B) Attach a generator and air conditioner compressor to the rotating shaft of the internal combustion engine. (C) If the generator is an AC machine, install a rectifier and convert it to DC. (If the generator is a DC machine, a rectifier is not required.) (D) A solar power generator, a storage battery, and an inverter / converter are connected to the DC circuit. (The solar power generator is omitted from the viewpoint of installation cost.) (E) The hot water of the internal combustion engine is guided to the heating and hot water supply equipment for use. (F) The internal combustion engine is operated only in two modes: complete stop and operation at an operating point at which the output is at maximum efficiency. As described above, a heat and electric energy supply device having a high fuel use efficiency constituted by a plurality of energy supply / accumulation sources.