JPH0155396B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a motor-driven air-conditioning/heating machine that includes a refrigeration cycle that has a compressor using the motor as a drive source and performs air conditioning and heating, and a hot water storage tank that stores heat recovered from the motor. 2. Description of the Related Art As an alternative to air conditioners in which a compressor of a refrigeration cycle is driven by an electric motor, air conditioners in which a compressor is driven by a prime mover are known. Such a motor-driven air conditioner/heater recovers exhaust heat from the motor using its cooling water, stores the recovered heat in a hot water storage tank,
It is used for hot water supply. Therefore, although the efficiency of the prime mover is lower than that of an electric motor, it has the advantage of having a large coefficient of performance in terms of primary energy because the exhaust heat of the prime mover is recovered. Therefore, in order to efficiently operate a motor-driven air conditioner/heater, it is necessary to provide a hot water storage tank for storing exhaust heat from the motor. Although the hot water supply load varies depending on the season, the type of residence, etc., it is preferable that the hot water in the hot water storage tank boils and reaches the temperature using only the exhaust heat of the prime mover generated only by the heating and cooling operation. In this case, there is no need to operate the prime mover for the sole purpose of storing hot water;
Therefore, fuel costs for hot water supply are unnecessary.
However, during the intermediate seasons such as spring and autumn, there is almost no need for air conditioning operation, so the prime mover for storing hot water must be operated. On days when hot water is low, it is not possible to store enough hot water to cover the daily hot water supply load, so it is necessary to operate exclusively for hot water storage, and the proportion of operation time dedicated to hot water storage is quite large throughout the year. It is known. In order to cover the hot water supply load in this case, the refrigeration cycle that forms the heat pump can be switched to circulate high-pressure refrigerant to the heat exchanger in the hot water storage tank, and the outdoor heat exchanger can be operated as an evaporator, or a separate The hot water in the hot water storage tank is heated to boiling temperature using an auxiliary heat source. However, in any case, operating exclusively for hot water storage will increase fuel consumption, so
It is necessary to shorten the dedicated operation time. This invention has been made in view of the above-mentioned circumstances, and is configured to absorb heat from the outside air into the motor cooling water, that is, circulating water, and store hot water when the motor is stopped using a surplus heat treatment heat exchanger. When there is no operation and the hot water supply load cannot be covered by the exhaust heat of the prime mover, the prime mover is operated exclusively for hot water storage for a short period of time, and the water in the hot water storage tank can be heated to boiling temperature with low fuel consumption. The purpose is to provide water heaters. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a refrigerant and hot water cycle diagram according to an embodiment of the present invention. In FIG. 1, 1 is a prime mover using an internal combustion engine, and the refrigeration cycle includes a compressor 2 driven by the prime mover 1, a four-way switching valve 3,
It is constructed using an outdoor heat exchanger 4, a throttle mechanism 5, and an indoor heat exchanger 6 as basic elements. In addition, a cooling water jacket 7 provided in the prime mover 1, a circulation pump 8 which is a means for conveying a heat medium such as hot water, an exhaust heat recovery heat exchanger 9, and a heat exchanger integrated with or close to the outdoor heat exchanger 4 are provided. Excess heat treatment heat exchanger 10 and hot water storage tank 1 provided in the air passage by the manual blower 15
1 constitutes the main part of the hot water supply functional element.
12 and 13 are solenoid valves for switching the hot water flow path;
16 is an auxiliary heat source that heats the hot water storage tank 11. In the air-conditioning/heating water heater configured as described above, when storing hot water associated with normal air-conditioning/heating operation, the solenoid valve 1
2 is closed, solenoid valve 13 is open, and circulation pump 8
The hot water conveyed by the drive exchanges heat with the water in the hot water storage tank 11, returns to the prime mover 1 through the solenoid valve 13, and then passes through the exhaust heat recovery heat exchanger 9 and returns to the hot water storage tank 11. Do a cycle. When the temperature inside the hot water storage tank 11 rises and reaches the temperature by continuing such operation, the solenoid valve 13 is closed, the solenoid valve 12 is opened, and the hot water recovered from the exhaust heat of the prime mover 1 is passed through the surplus heat treatment heat exchanger 10. After being circulated and its temperature reduced, it is returned to the cooling water jacket 7 of the prime mover 1. The above is a case of normal cooling or heating operation by the prime mover, and if surplus heat is generated, there is no problem because the hot water supply load can be sufficiently covered. However, the amount of exhaust heat from the prime mover is dependent on the heating and cooling operation time, and in partial load operation where the heating and cooling load is around 50%, the amount of stored hot water is insufficient even in the summer when the hot water supply load is low, and there is a significant shortage in the winter. In such a case, in one embodiment of the present invention, hot water storage operation is performed without driving the prime mover 1. That is, the water temperature in the hot water storage tank 11 and the outside air temperature are detected by a temperature detection means (not shown), and if the water temperature in the hot water storage tank 11 is lower than the outside air temperature, the surplus heat treatment heat exchanger 10 removes the prime mover cooling water. In this case, the solenoid valve 12 is opened and the solenoid valve 13 is closed.
The hot water leaving the hot water storage tank 11 passes through the solenoid valve 12 and enters the surplus heat treatment heat exchanger 10, where the temperature of the circulating water is increased, returns to the prime mover 1, and enters the hot water storage tank 11 again to increase the temperature of the stored hot water. Perform operation to raise the temperature. The test results from such operation are shown in the table below.

[Table] However, the boiling temperature was 80℃. The temperature of the water supplied to the hot water tank does not change much during the day and is almost constant, but the outside temperature changes relatively large, with a difference of about 5 to 10 degrees in the morning, evening, and daytime. By being able to heat the water to a temperature close to the outside temperature using a surplus heat treatment heat exchanger,
The results show that it is possible to reduce fuel costs by more than 10% on average per year, and the economic effect is proven as shown in Figure 2. In this case, if there is sunlight irradiation, the surplus heat treatment heat exchanger, outdoor heat exchanger, etc. absorb radiant heat and become higher than the outside air temperature, so the circulating water temperature may become higher than the outside air temperature. It is preferable to install the surplus heat treatment heat exchanger in a place that receives sunlight. Naturally, in hot water storage that absorbs heat from outside air, if the temperature difference between the outside air temperature and the water in the hot water storage tank is small, even if the above-mentioned hot water storage operation that absorbs heat from outside air is performed for a long time, the amount of stored hot water will not increase much. The hot water storage effect decreases. Therefore, it is preferable to perform a hot water storage operation that absorbs heat from the outside air under a predetermined temperature difference, specifically, a temperature difference of about 1 to 2 degrees. Furthermore, during the hot water storage operation that absorbs heat from the outside air, it is preferable to operate the outdoor heat exchanger blower to improve the heat absorption effect on the circulating water by the surplus heat treatment heat exchanger. FIG. 2 shows another embodiment of the invention. In FIG. 2, the same symbols as in FIG. 1 indicate the same parts, 17 is a side pipe that bypasses the cooling water jacket 7 of the prime mover 1 and the exhaust heat recovery heat exchanger 9, and 18 is a side pipe installed in the side pipe 17. It is a normally closed solenoid valve. During partial load operation of the prime mover 1, the temperature of the prime mover 1 and the exhaust heat recovery heat exchanger 9 is higher than the outside air temperature, but the temperature of the circulating water in the hot water storage tank 1 is often lower than the outside air temperature. . Further, during the hot water storage operation that absorbs heat from the outside air, the prime mover 1 and the exhaust heat recovery heat exchanger 9 are just a circulation path and serve as resistance to the circulating water, and there is no need to circulate the water. Therefore, in these cases, using control means such as the side pipe 17 and the solenoid valve 18, the solenoid valve 18 is opened to allow circulating water to pass through the side pipe 17, and the prime mover 1 and the exhaust heat recovery heat exchanger 9 are By adjusting the amount of circulating water that passes through the system, the heat absorption effect of the outside air is improved. Note that the configuration and basic operation of the embodiment shown in FIG. 2 other than those described above are the same as those shown in FIG. 1, so explanations thereof will be omitted. As explained above, the prime mover-driven air conditioning/heating/water heater of the present invention utilizes the surplus heat treatment heat exchanger,
By absorbing heat from the outside air into the circulating water and storing hot water when the prime mover is stopped, the operating time dedicated to hot water supply can be shortened and annual fuel consumption can be reduced. Additionally, as the efficiency of the prime mover and the coefficient of performance of the refrigeration cycle increase, the displacement will also decrease even if the gas input (Kcal/b) to the prime mover decreases. Although this is desirable from the standpoint of equipment efficiency, From this point of view, it becomes impossible to satisfy the hot water supply load, and hot water runs out easily at peak loads, but the present invention has the advantage of being able to overcome these drawbacks.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a motor-driven cooling/heating/water heater according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a motor-driven cooling/heating/water heater according to another embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Prime mover, 2... Compressor, 3... Four-way switching valve, 4... Outdoor heat exchanger, 5... Throttle mechanism, 6...
...Indoor heat exchanger, 7...Cooling water jacket, 8...
...Circulation pump, 9...Exhaust heat recovery heat exchanger, 10...
... Surplus heat treatment heat exchanger, 12, 13 ... Solenoid valve,
15...Blower for outdoor heat exchanger, 16...Auxiliary heat source, 17...Side pipe, 18...Solenoid valve. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In a motor-driven air-conditioning/heating machine equipped with a refrigeration cycle that has a compressor using the motor as a drive source and performs air-conditioning and heating, and a hot-water storage tank that stores the heat recovered from the motor, the hot-water storage during air-conditioning/heating operation is provided. Equipped with a surplus heat treatment heat exchanger that radiates the heat recovered from the prime mover to the outside air when the temperature inside the tank reaches the boiling temperature, and when the prime mover is stopped, this heat exchanger absorbs heat from the outside air to the prime mover cooling water and stores hot water. A motor-driven air-conditioning, heating, and water heater characterized by comprising: 2. The prime mover-driven air-conditioning/heating water heater according to claim 1, wherein the heat-absorbing hot water storage is performed by the surplus heat treatment heat exchanger when the difference between the outside air temperature and the temperature inside the hot water storage tank is greater than or equal to a preset temperature difference. 3. The surplus heat treatment heat exchanger is disposed in the air path of an outdoor heat exchanger blower, and the blower is driven when the surplus heat treatment heat exchanger absorbs heat and stores hot water, according to claim 1 or 2. Motor-driven heating, cooling, and water heater. 4 A control means such as a bypass pipe that bypasses the prime mover and a solenoid valve that opens and closes the bypass pipe is installed in the cooling water circulation path of the prime mover, and the prime mover is bypassed and hot water is absorbed and stored by the surplus heat treatment heat exchanger. A motor-driven air-conditioning/heating water heater according to claim 1, 2, or 3.