JPS61122450A - Engine-driven heat pump hot water supply device - Google Patents

Abstract

PURPOSE:To raise the temperature of hot water supply by heating the hot water simultaneously by a heat pump and exhaust heat, and, in addition to that, by heating the water in an exhaust heat water heater by operating the engine only after the compressor of the heat pump is stopped. CONSTITUTION:When the heating is started for hot water supply at T1, since the coolant temperature TC in or around a coolant temperature sensor 14 of an engine 1 and a condenser 4, the water is heated by a heat pump refrigerant circuit A and a waste heat recovering circuit B. When the refrigerant temperature in the condenser 4 becomes a saturated temperature TC2 under the allowable refrigerant pressure at T2, an electromagnetic clutch 2 is disengaged to stop the compressor 3 and stop heating the water by the heat pump refrigerant circuit A. From this time on, only the engine 1 is operated, and the water is heated by the exhaust heat of the engine operated in the idling mode. In this manner, the hot water is heated from 60 deg.C to 85 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an engine-driven heat pump water heater, and more particularly to a method for ensuring a high temperature of hot water.

Conventional configurations and their problems Engine-driven heat pump systems have recently been introduced due to the difficulty of constructing new power plants and the fact that there is a surplus of city gas in the summer while electricity demand peaks in the summer. has been attracting attention.

This engine-driven heat pump device uses the engine to drive the compressor to perform air-conditioning and heating operations and heat pump hot water supply operations, and at the same time recovers engine exhaust heat (exhaust heat from the cylinder head and exhaust gas) and uses it for hot water supply and space heating. It is characterized by high efficiency.

The third factor is a schematic configuration of a conventional engine-driven heat pump water heater. The problems of the conventional engine-driven heat pump water heater will be explained with reference to FIG.

In the figure, 1' is an engine, 2' is a compressor driven by the engine 1', and 3' is hot water 5' in a heat storage tank 4'.
6' is a pressure reducer, and 7' is an evaporator, forming a heat pump refrigerant circuit A'. Further, 8' is a pump directly connected to the shaft of the engine 1, and 9' is a pump that circulates cooling water (not shown) to recover exhaust heat from the cylinder section 10' of the engine 1' and heat it in the condenser 3'. This is a heat exhaust device that heats the heated hot water supply S', and constitutes an exhaust heat recovery circuit B'. 1
1' is an electric pump that guides the hot water 5' from the heat storage tank 4' to the condenser 3' and then to the heat exhauster 9', and combines the refrigerant condensation heat (up to about 55°C) from the heat pump refrigerant circuit A' with exhaust water. Eisin waste heat (up to about 85°C) is recovered from the heat recovery circuit B', and high temperature hot water 5' is obtained in the heat storage tank 4'.

However, in the conventional engine-driven heat pump water heater, the engine 1' and compressor 2' are coaxially connected.
Since the operating timings are the same, the operating time of the engine 1' is limited as the refrigerant pressure in the heat pump refrigerant circuit A' side 6 increases. That is, as the engine 1 operates, the temperature of the hot water 5' in the heat storage tank 4' gradually increases, and the refrigerant pressure in the condenser 3' also gradually increases. Generally, when the refrigerant is Freon R-22, it is approximately 2
The pressure is limited to 9/crtfy from 3 to '24. Therefore, the refrigerant pressure in the condenser 3' increases before the engine 1' itself is able to warm up sufficiently, that is, the exhaust heat from the exhaust heat generator 9 side of the engine 1' is not sufficiently recovered.
The operation of the engine 1' and compressor 2' had to be stopped.

In that case, the water temperature obtained from the condenser 3 is at most about 5
5°C, and it was difficult to obtain hot water 5 at a high temperature in the heat storage tank 4'.

Purpose of the Invention The present invention has been made in view of the above-mentioned problems.The present invention recovers engine exhaust heat only by idling the engine after simultaneous operation of engine exhaust heat and heat pump operation. The goal is to secure hot water at a temperature of 80°C.

Structure of the Invention To achieve this object, the present invention provides a heat pump refrigerant circuit and an exhaust heat recovery circuit with a compressor driven by an engine via an electromagnetic clutch, and a compressor driven by the electromagnetic clutch by detecting the refrigerant temperature of the condenser. with a refrigerant temperature sensor that turns on and off the
A coolant temperature sensor is provided to detect the coolant temperature of the engine and turn the engine on and off, and further, the operating temperature of the coolant temperature sensor is set higher than the coolant temperature sensor to heat the hot water using the heat exhaust unit alone. It is configured to do this.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 shows an example of a schematic configuration of an engine-driven heat pump water heater of the present invention, and FIG. 2 similarly shows its operating pattern and temporal changes in cooling water temperature and refrigerant temperature.

In Fig. 1, 1 is an engine, 2 is an electromagnetic clutch, and 3
is a compressor driven by the engine 1 via an electromagnetic clutch 2; 4 is a condenser that heats the hot water 6 in the heat storage tank 5; 7 is a pressure reducer; and 8 is an evaporator; these are connected to produce a heat pump refrigerant. It constitutes circuit A. Further, in this embodiment, 9 is a pump coaxial with the shaft of the engine 1, and 10 is a heat exhauster, which circulates cooling water (not shown) and recovers exhaust heat from the cylinder head 11 of the engine 1. These are connected to form an exhaust heat recovery circuit B. Reference numeral 12 denotes an electric pump, which is configured to guide the hot water 6 from the heat storage tank 5 to the condenser 4 and then to the heat exhaust device 10, and collects the refrigerant condensation heat from the heat pump refrigerant circuit A and the engine exhaust heat from the exhaust heat recovery circuit B. to recover. 13
14 is a coolant temperature sensor that detects the coolant temperature (or pressure) and turns on and off the electromagnetic clutch 2; 14 is a coolant temperature sensor that detects the coolant temperature and turns the engine 1 on and off; its operating temperature is as follows. The temperature is selected to such an extent that if the temperature rises above this level, a problem will occur in the engine 1. 15 is a control device that processes signals from the refrigerant temperature sensor 13 and the coolant temperature sensor 14 to turn on and off the electromagnetic clutch 2 and the engine 1;
approximately 90°C) is the operating temperature of the refrigerant temperature sensor 13 (approximately 55°C).
C), and even if the refrigerant temperature sensor 13 operates and the electromagnetic clutch 2 is turned off to stop the heating of the hot water supply 6 by the condenser 4 of the heat pump refrigerant circuit A, the cooling water temperature sensor 14 remains unchanged. The system is configured so that the hot water 6 is heated by the heat exhaust device 10 until the engine 1 starts operating.The operation under the above configuration will be described below with reference to FIG. I will explain.

When hot water heating operation is started at time T1, electric pump 1
Since the temperature of the coolant temperature sensor 14 and the refrigerant temperature Tc of the condenser 4 are still low (TC1°C), the electromagnetic clutch 2 is turned on by the detection of the refrigerant temperature sensor 13. , drives compressor a.

As a result, the heat pump refrigerant circuit A operates, and the heat of refrigerant condensation is applied to the hot water supply 6 in the condenser 4 .

On the other hand, since engine 1 is driving, pump 9-
At the same time as the engine rotates, the cooling water temperature TV also rises, and as a result, the engine exhaust heat from the cylinder head 11 is transferred to the exhaust heat generator 1.
0, and here the exhaust heat recovery circuit B is activated to further heat the hot water 6 at the outlet of the condenser 4.

The coolant temperature sensor 14 is designed to operate at about 90'C, and although the coolant temperature TV gradually rises after the engine 1 is operated as shown in FIG. It does not operate and therefore the engine 1 does not stop. As a result, the temperature of the hot water 6 increases due to the condensation heat of the condenser 4 due to the heat pump operation and the engine exhaust heat from the heat exhaust device 10.

As the operation progresses, the temperature of the hot water supply 6 increases, and the refrigerant pressure in the heat pump refrigerant circuit A also increases, but the allowable refrigerant pressure (23 to 24 kg/cI in the case of Freon R-22)
ly) is the limit, and if the refrigerant temperature in the condenser 4 reaches Te3 (saturation temperature of allowable refrigerant pressure) at time T2, the refrigerant temperature sensor 13 turns off the electromagnetic clutch 2,
That is, the compressor 3 is separated from the rotation of the engine 1, the compressor 3 is stopped, and refrigerant heat recovery from the condenser 4 is stopped.

At this point, the temperature of the hot water supply 6 has risen to about 60°C.

After that, the compressor 3 is not driven and only the engine 1 is operated, which is a so-called idling operation.

Although the amount of exhaust heat from the engine 1 decreases or disappears because no load is applied, the cooling water temperature TV, that is, the hot water supply 6, continues to rise.

Then, at time T3, the coolant temperature reaches 90°C, the coolant temperature sensor 14 operates, and the control device 15 stops the engine 1, completing the hot water heating.

At that time, the temperature of the hot water supply 6 in the hot water storage tank 5 rises to about 85°C, and a sufficiently high temperature can be ensured.

Effects of the Invention As described above, the present invention not only simultaneously pumps and heats the condensed heat of the heat pump refrigerant circuit and the exhaust heat generator of the exhaust heat recovery circuit, but also allows only the engine to operate independently after turning off the compressor using an electromagnetic clutch. Because hot water is heated only by a heat exhaust device, the hot water temperature used to be around 60°C, but now it is about 85°C.
It has the effect of being able to raise the temperature to about °C.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an engine-driven heat pump water heater according to an embodiment of the present invention, and FIG. 2 shows the operating pattern, cooling water temperature,
FIG. 3 is a schematic configuration diagram of a conventional engine-driven heat pump water heater. 1... Engine, 2... Electromagnetic clutch, 3
... Compressor, 4 ... Condenser, 6 ... Hot water supply, 7 ... Pressure reducer, 8 ... Evaporator, 1
0... Heat exhaust device, 13... Refrigerant temperature sensor, 14... Cooling water temperature sensor, A... Heat pump refrigerant circuit, B... Exhaust heat recovery circuit.

Claims (1)

[Claims] An engine, an electromagnetic clutch, a compressor driven by the engine via the electromagnetic clutch, a condenser for heating hot water, a pressure reducer, a heat pump refrigerant circuit connected to an evaporator, and circulating cooling water to the engine. An exhaust heat recovery circuit is provided that has a heat exhaust device that recovers engine exhaust heat and further heats the hot water heated by the condenser, and detects the refrigerant temperature of the condenser to turn on and off the electromagnetic clutch. A sensor and a cooling water temperature sensor that detects the temperature of the cooling water and turns on and off the engine are provided, and the operating temperature of the cooling water temperature sensor is set higher than that of the refrigerant temperature sensor, and the heat exhauster is used alone. An engine-driven heat pump water heater configured to heat the hot water.