JPH0612205Y2 - Combined heat and power equipment - Google Patents

Description

Detailed Description of the Invention A. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined heat and power supply device that drives a generator by an engine such as a gas engine to generate electric power and at the same time recovers heat energy generated by the engine to waste heat and uses it for hot water supply.

B. SUMMARY OF THE INVENTION The present invention circulates cooling water in an engine that drives a generator,
In a combined heat and power device that uses the cooling water to recover the waste heat of the engine as hot water, the suction side and the discharge side of a water feed pump that feeds the cooling water to the engine are connected by a bypass passage and the bypass passage is connected to the bypass passage. The flow rate adjusting means is interposed, and the amount of water flowing through the bypass passage is changed by the flow rate adjusting means to make the actual discharge pressure and flow rate of the water feeding pump variable, which facilitates matching of the water feeding pump performance to the entire system. is there.

C. 2. Description of the Related Art In recent years, from the viewpoint of energy saving, a combined heat and power supply device has been considered in which waste heat of an engine such as a gas engine that drives a generator is effectively recovered and utilized as heat energy to improve the overall energy efficiency. There is.

FIG. 2 is a schematic configuration diagram showing an example of a conventional combined heat and power supply device. As shown in FIG. 2, in this apparatus, the diesel gas engine 11 drives the generator 12 to obtain an electric output, while the circulating cooling water cools the engine 11 and the engine exhaust part 13, and the cooling that is heated there. Recovers thermal energy from water. That is, the cooling water is fed from the low temperature water tank 14 into the engine 11 by the water feed pump 15, where the engine 11 is cooled, and then is guided into the exhaust gas water heater 16 to cool the exhaust portion 13 to become hot water. And returned to the high temperature water tank 17. On the other hand, the hot water in the high temperature water tank 17 is guided to the water-to-water heat exchanger 19 by the pump 18, and the heat energy of the hot water is taken out as a heat output to the running water being sent by the pump 20. Further, the hot water from which the heat is removed by the heat exchanger 19 is returned to the low temperature water tank 14.

D. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention By the way, in the above-mentioned cooling water circulation circuit, the capacity, discharge pressure, water supply amount, etc. of the water supply pump 15 for supplying the cooling water to the engine 11 are suitable for the piping system of the entire apparatus. Must-have. That is, if the capacity of the water supply pump 15 is insufficient, the engine 11 is not sufficiently cooled, and conversely, if the capacity is excessive, the engine 11 is cooled more than necessary and the efficiency of the engine 11, that is, the power generation efficiency is reduced. Decrease, both of which lead to a decrease in overall energy efficiency.

However, the performance required for the water pump 15 depends on various conditions such as the route of the piping system of the entire apparatus, the diameter of the piping material, and the equipment used. Conventionally, after all these conditions are determined. There was a problem that the specification of the water pump 15 could not be determined unless it was done. Furthermore, after the decision,
For example, when conditions change such as a change in the piping route at the site, it has been difficult to quickly respond to such changes.

The present invention solves the conventional problems in such a combined heat and power supply device, and provides a combined heat and power supply device for facilitating matching with the entire system of a water supply pump that supplies cooling water to an engine. It is an object.

E. Means for Solving the Problems In order to achieve the above object, in a combined heat and power supply device according to the present invention, cooling water is circulated through an engine that drives a generator, and the cooling water collects waste heat of the engine to generate hot water. In the combined heat and power supply device used as, the suction side and the discharge side of the water feed pump for feeding the cooling water to the engine are connected by a bypass passage, and a flow rate adjusting means is provided in the bypass passage.

F. A part of the cooling water flows through the bypass passage without passing through the water supply pump, and the amount of water flowing therethrough is controlled by the flow rate adjusting means, so that the cooling water flowing through the bypass passage is substantially effective for the engine of the water supply pump. Change the discharge pressure and discharge water volume.

G. Embodiment An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic configuration diagram of a combined heat and power supply apparatus according to an embodiment of the present invention. In FIG. 1, the same parts as those of the conventional device shown in FIG. 2 are designated by the same reference numerals, and the duplicated description will be omitted in the following description.

As shown in FIG. 1, the suction side “a” and the discharge side “b” of the water feed pump 15 for feeding the cooling water to the diesel gas engine 11 are connected by a bypass passage 21, and the flow rate is adjusted in the middle of the bypass passage 21. The valve 22, which is a means, is interposed.

With such a configuration, a part of the cooling water sent to the engine 11 does not pass through the water pump 15 and the bypass passage 2
1 and its flow rate can be controlled by the flow control valve 22. Therefore, by finely adjusting the flow rate adjusting valve 22 and changing the amount of the cooling water flowing through the bypass passage 21, it becomes possible to change the substantial discharge pressure or discharge flow rate of the water feed pump 15 to the engine 11.

For example, the capacity of the water supply pump 15 is selected to match the maximum discharge pressure that can be considered at the stage of designing the entire apparatus, and as a result of actual operation at the site, a discharge pressure lower than that is appropriate. When the determination is made, the discharge pressure can be substantially reduced by opening the flow rate adjusting valve 22, and the most efficient operation can be performed.

Although the valve is used as the flow rate adjusting means in the above-described embodiment, a variable throttle such as an orifice may be used instead.

H. Effects of the Invention As described above with reference to the embodiments, according to the present invention,
In the combined heat and power supply device, since the water supply pump for supplying the cooling water to the engine is provided with the bypass passage having the flow rate adjusting means, by adjusting the amount of water flowing through the bypass passage by the flow rate adjusting means, the discharge pressure of the water supply pump, It is possible to easily control the discharge flow rate, thereby making it possible to properly match the water pump with the entire system and improve the overall energy efficiency.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a combined heat and power supply device according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a combined heat and power supply device according to a conventional example. In the drawings, 11 is an engine, 12 is a generator, 14 is a low temperature water tank, 15 is a water feed pump, 17 is a high temperature water tank, 21 is a bypass passage, and 22 is a flow control valve.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. In a combined heat and power supply device, wherein cooling water is circulated through an engine for driving a generator, and waste heat of the engine is recovered by the cooling water and used as hot water, the cooling water is sent to the engine. A combined heat and power supply device characterized in that a suction side and a discharge side of a water feed pump are connected by a bypass passage and a flow rate adjusting means is interposed in the bypass passage.