JPS5929957A - Prime mover driving heat pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump that drives a compressor of a refrigeration cycle by means of a prime mover comprised of an internal combustion engine.

The above-mentioned heat pump is equipped with a refrigeration cycle, a prime mover consisting of an internal combustion engine that drives the compressor, and a hot water tank that stores heat by heating the circulating water that recovers the exhaust heat of the prime mover. Are known. This prime mover-driven heat pump has the advantage of having a large coefficient of performance in terms of -order energy because it can recover exhaust heat from the prime mover using the coolant of the prime mover, store it in a hot water tank, and use it for hot water supply.

FIG. 1 shows a hot water tank portion of a conventional motor-driven heat pump as described above. In Figure 1, 9 is a hot water tank, 10 is a hot water tank 9
A heat exchanger for hot water storage is disposed in the inner lower part, 11 is a water supply pipe that opens at the bottom of the hot water tank 9, and 12 is a water supply pipe that opens at the upper end of the hot water tank 9.

In the conventional system configured as described above, circulating water, which is cooling water that has recovered exhaust heat from the prime mover, flows to the hot water storage heat exchanger 10 as shown by the arrow in FIG. By heating the stored hot water and gradually raising the temperature of the stored water in the hot water tank 9 by natural convection, there is almost no difference in the temperature inside the tank between the upper and lower parts, and it is possible to uniformly heat the lower part. Therefore, the effective amount of hot water storage can be increased. However, if the prime mover is only operated for cooling or heating,
The temperature of the hot water stored in the hot water tank rises almost uniformly from top to bottom and in proportion to the operating time of the prime mover, so it takes quite a long time to reach the temperature required for hot water supply, which is generally 45°C or higher. Even if a sufficient amount of heat is stored in the hot water tank, the hot water temperature is lower than the required temperature, which often causes dissatisfaction among users.

This invention is an attempt to solve the above-mentioned drawbacks of the conventional ones, and in the above-mentioned motor-driven heat pump, a heat exchanger is introduced in which circulating water, which has recovered exhaust heat from the motor, enters the hot water tank from the upper part of the hot water tank. By providing a pipe and a hot water storage heat exchanger connected to the lower end of the heat exchange pipe and from which circulating water is output from the lower part, hot water can be obtained by short-term operation of a prime mover during hot water supply. It is an object.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. FIG. 2 shows the cycle system of this embodiment. In Figure 2, 1 is an internal combustion (prime motor consisting of an intermittent engine), 2 is a prime mover 1
3 is a four-way valve, 4 is an indoor heat exchanger, 5 is a throttle mechanism, and 6 is an outdoor heat exchanger. A refrigeration cycle is constructed with the main components being a compression valve 2, a four-way valve 3, an indoor heat exchanger 4, a throttling mechanism 5, and an outdoor heat exchanger 6. By switching the flow direction of the refrigerant, it can be used for heating and cooling. Also, reference numeral 7 refers to a flow path for circulating the cooling water of the prime mover 1 and recovering its heat; and 8, this flow path 7. 9 is a hot water tank, 10 is a hot water tank 9
13 is a hot water control valve such as a thermo valve installed on the upstream side of the hot water tank 9 in the flow path 7;
14 is a bypass flow path which connects the hot water tank 9 from the upstream side near the hot water control valve 13 to the downstream side;
Reference numeral 15 denotes a resistance portion such as a thin tube provided in the bypass flow path 14. Further, FIG. 3 shows the hot water tank portion of this embodiment. A heat exchange pipe 16 extends vertically from the top to the bottom of the hot water tank 9, and the lower end of the heat exchange pipe 16 is used for hot water storage. The upper end of the heat exchanger 10 is connected. This heat exchanger 10
is formed in a meandering or spiral shape and is disposed in the lower part of the hot water tank 9, and the lower end of the hot water storage heat exchanger 10 extends from the lower part of the hot water tank 9 to the outside thereof. Further, a water supply pipe 11 and a hot water supply pipe 12 are opened at the bottom and top end of the hot water tank 9, respectively.

In the prime mover-driven heat pump configured as described above, when the prime mover 1 is operating, the cooling water is used to drive the pump 8.
The circulating water that has recovered the exhaust heat from the prime mover 1 is cooled by exchanging heat with the hot water stored in the hot water tank 9 through the heat exchange pipe 16 and the hot water storage heat exchanger 10, and is then reused in the prime mover 1. Repeat the cycle back to step 1.

In the hot water tank 9, the circulating water that has recovered the exhaust heat of the prime mover 1 enters from the top and flows downward through the heat exchange pipe 16, after which it is passed through the hot water storage heat exchanger installed at the bottom of the hot water tank 9. vessel 10
The circulating water comes out from the lower end of the hot water tank 9 after exchanging heat with the stored hot water inside the tank 9. Immediately after the circulating water enters the hot water tank 9, it exchanges heat with the stored hot water in the heat exchange pipe 16. The temperature of the hot water is gradually lowered, and the remaining heat is exchanged with the 10 heat exchangers for hot water storage. For this reason, when the temperature of the hot water stored in the hot water tank 9 is low, there is a large temperature difference between the temperature of the circulating water that has recovered the exhaust heat of the prime mover 1 (and the heat exchange pipe 16
In other words, in the upper part of the hot water tank 9, heat is exchanged to heat the stored hot water. Furthermore, if the operation of the prime mover 1 continues for a certain period of time and the temperature of the stored hot water rises and the temperature difference between it and the circulating water decreases, the heat exchange capacity of the heat exchange tube 16 decreases.
The amount of heat exchanged by the hot water storage heat exchanger 10 increases, and the stored hot water is mainly heated from the lower part of the hot water tank 9.

Therefore, in this embodiment, since the stored hot water is first heated from the upper part of the hot water tank 9, it can be used for purposes other than dispensing a large amount of hot water at once, such as dispensing to a bathtub, i.e. dispensing a small amount of hot water for use in the washroom, kitchen, etc. Sometimes, by simply operating the prime mover 1 for a short period of time, high-temperature water of 115°C or higher can be produced. You can eliminate the need for a heat source for the vessel.

In addition, in this example, the heat exchange of the stored hot water in the hot water tank is by natural convection, so the heat passage rate is relatively small compared to forced convection, but this is because fins are installed as heat exchange tubes. By using the enlarged heat transfer surface (=J),
This can be solved by increasing the heat exchange capacity and by laying the piping in a straight line from the top to the bottom of the hot water tank instead of meandering. This heat exchanger can be suspended in the hot water tank against the load, and the problem of vibration of the prime mover can also be solved.

Furthermore, in this example, the hot water stored in the hot water tank is heated to a high temperature from the top, so the high temperature hot water output ability does not depend much on the operating time of the prime mover, and hot water is sequentially supplied from the hot water pipes that open at the top of the hot water tank. This increases the effective amount of hot water.

In this embodiment, the hot water supply tank 9
Input circulation: The temperature can be set to a preset temperature in Ftll-7, and the circulating water can be circulated. therefore,
Another advantage is that the high-temperature stored water heated to a boiling temperature of 80 to 90 degrees Celsius from the top of the hot water tank 9 can be discharged for normal hot water supply loads such as washing and use in the kitchen. .

In the above-described embodiment, the heat exchange pipe is inserted into the hot water tank from the two ends, but the present invention also allows the inlet pipe to be inserted from the side or bottom of the hot water tank. If the connected heat exchange pipe passes through the upper part of the hot water tank and then reaches the hot water storage heat exchanger at the lower part, almost the same effect as the above-mentioned embodiment can be obtained, so this type of pipe can also be used. within the scope of this invention.

As explained above, the prime mover-driven heat pump according to the present invention heats the hot water stored in the tank from the upper part of the hot water tank when the prime mover is operating, and ultimately heats the stored hot water in the lower part, so that the prime mover is short-lived. It has the effect of producing the necessary high-temperature water in just a few hours of operation.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the hot water tank portion of a conventional motor-driven heat pump, FIG. 2 is a cycle system diagram of a motor-driven heat pump according to an embodiment of the present invention, and FIG. 3 is a longitudinal cross-sectional view of the hot water tank portion of the same. It is a diagram. 1... Prime mover, 2... Compressor, 3... Four-way valve, 4... Indoor heat exchanger, 5... Throttling mechanism,
6...Outdoor heat exchanger, 7...Flow path, 9...
Hot water tank, 10... Heat exchanger for hot water storage, 11...
- Water supply pipe, 12... Hot water supply pipe, 13... Hot water control valve, 14... Bypass flow path, 15... Resistance section, 16... Heat exchange pipe. Note that the same reference numerals in the figures indicate the same or corresponding parts. 1φ−〆he patent applicant agent...
1. Patent Attorney Masaaki Kado ゛ 11.
1, -m-, ~, -1+,) f1 figure f2 figure spear 3 figure -292-

Claims (4)

[Claims] (1) A refrigeration cycle consisting of a compressor, an indoor heat exchanger, a throttling mechanism, and an outdoor heat exchanger as main parts, a prime mover consisting of an internal combustion engine that drives the compressor, and a system that recovers the exhaust heat of this prime mover. In a prime mover-driven heat pump equipped with a hot water tank that stores heat by heating with circulating water, the hot water tank includes a heat exchange pipe into which circulated water that has recovered exhaust heat from the prime mover enters from the upper part of the hot water tank, and a heat exchange pipe of the heat exchange pipe. A motor-driven heat pump characterized by being provided with a heat exchanger for hot water storage connected to the lower end and from which circulating water comes out. (2) A heat exchange pipe is arranged in a straight line from the top to the bottom in the hot water tank, and a meandering or spiral hot water storage heat exchanger is arranged in the lower part of the hot water tank, and this heat exchange The motor-driven heat pump according to claim 1, wherein the heat transfer area of the vessel is larger than the heat transfer area of the heat exchange tube. (3) The prime mover-driven heat pump according to claim 1 or 2, comprising a heat exchange tube having an enlarged heat transfer surface. (4) A hot water control valve that circulates hot water entering the hot water tank at a preset temperature in the circulating water flow path that recovers heat from the prime mover, and a hot water control valve that bypasses the hot water tank when controlled by this control valve. A motor-driven heat pump according to claim 1, 2, or 3, comprising a bypass flow path and a bypass flow rate limiting resistor provided in the bypass flow path.