JPH0226153B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an antifreeze device for a heat pump device for hot water supply, etc., which uses a heat pump to heat water in a hot water storage tank.

[Prior art]

The conventional heat pump device for hot water supply as described above will be explained with reference to FIG.

In Fig. 1, 1 is a heat pump for heating;
2 is a hot water storage tank, 3a is a return pipe to the hot water storage tank 2, 3b
is the outgoing pipe to heat pump 1, and pipe 3
The heat pump 1 and the hot water storage tank 2 are communicated through a and 3b. Reference numeral 4 indicates a circulation pump installed in the pipe 3b, and reference numeral 8 indicates the inflow of city water from the city water intake 5 into the suction side pipe _3b1 of the circulation pump 4 via the solenoid valve 6 and the electric valve 7 capable of adjusting the flow rate through the connection part 8a. water supply piping. Further, 9 is a pipe for circulating hot water on the load side, 10 and 11 are a circulation pump and a faucet provided in the load side pipe 9, 12 is a control device, 13 is a water level switch provided in the hot water tank 2, and 14 is a water level switch provided in the hot water tank 2. Temperature sensor installed at the bottom of hot water tank 2, 1
5 is a pipe 3a on the outlet side of the heat pump 1
This is a temperature sensor installed in the

Next, the operation of the apparatus shown in FIG. 1 will be explained. In this heat pump device for hot water supply, the circulation pump 10 on the load side is constantly driven, and when hot water is used from the faucet 11, the water that returns from the piping 9 on the load side to the hot water tank 2 decreases, and the water inside the hot water storage tank 2 decreases. The water level drops below the full water level A. This drop in water level is detected by the water level switch 13 and a signal is sent to the control device 12, which opens the solenoid valve 6 and drives the heat pump 1 and the circulation pump 4. To replenish water to the hot water storage tank 2, city water enters the water supply pipe 8 from the intake port 5, passes through the solenoid valve 6 and the electric valve 7, passes through the connection part 8a, and the suction side pipe _3b1 , and is sucked into the circulation pump 4. , is sent to the heat pump 1, heated there, and supplied to the hot water storage tank 2 through the piping 3a. At this time, the amount of make-up water is controlled by operating the electric valve 7 whose opening degree is adjusted by the control device 12 based on the detection signal of the temperature sensor 15 so that the outlet water temperature of the heat pump 1 is constant, for example, 55°C. . That is, when the temperature detected by the temperature sensor 15 is lower than the set value, the electric valve 7 gradually closes to reduce the supply of city water, and as the temperature rises, the electric valve 7 gradually opens to increase the supply of city water.
Since the amount of water flowing into the heat pump 1 is constant, the water for the shortage is supplied from the hot water storage tank 2 and mixed with the supplied city water to feed the heat pump 1.
flows into. In this way, hot water at a constant temperature is supplied to the hot water tank 2, and the water level gradually rises. When the water level in the hot water storage tank 2 reaches the full water level A, the solenoid valve 6 closes and the heat pump 1 and circulation pump 4 stop. When the water temperature in the hot water tank 2 falls below a certain level, such as 50°C, due to heat loss when the hot water storage tank 2 is at the full water level A, the temperature sensor 14 detects this and the control device 12 controls the heat pump 1 and the circulating water. The pump 4 is driven to perform a heat retention operation.

Further, the freezing prevention operation of the pipes 3a and 3b is automatically performed by the above-mentioned heat retention operation performed by the temperature sensor 14 provided in the hot water storage tank 2.

However, when the conventional hot water heat pump device configured as described above is installed in a cold region, the temperature of the water in the piping drops rapidly due to a drop in the temperature of the hot water storage tank, or if the heat pump device is operated without heat retention operation. However, there was a drawback that the water in the pipes could freeze.

[Summary of the invention]

This invention provides a heat pump and a hot water storage tank with antifreeze piping that connects the vicinity of the hot water tank inlet of the piping that circulates water through the hot water storage tank to the bottom of the hot water storage tank via a switching valve, a connection part of the water supply piping, and a circulation pump suction port. The control device is equipped with a control device having a temperature sensor that detects the water temperature between the temperatures, and when the water temperature detected by the temperature sensor is below the set value, the hot water at the bottom of the hot water storage tank is connected to the piping through the antifreeze piping. It is an object of the present invention to provide a freeze prevention device for a heat pump device that can suppress the temperature drop of hot water in a hot water storage tank as much as possible by exchanging the cold water of the heat pump device and eliminate the drawbacks of the conventional devices described above.

[Embodiments of the invention]

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

In Fig. 2, 1 is a heat pump, 2 is a hot water storage tank, 3a is a return pipe to the hot water storage tank 2, 3b is an outgoing pipe to the heat pump 1, 4 is a circulation pump, 5 is a city water intake port, 6 is a solenoid valve, 7 is an electric valve that can adjust the flow rate, 8 is a water supply pipe, 8a is a connection part of the water supply pipe 8 to the pipe 3b, 9 is a circulation pipe on the load side, 10
11 is a circulation pump on the load side, 11 is a faucet, 13 is a water level switch, and 14 and 15 are temperature sensors, which have the same structure as the conventional heat pump device described above. Further, 16 is a temperature sensor installed in the suction side pipe 3b1 between the connection part 8a of the water supply pipe 8 and the suction port of the circulation pump ₄ , and 17 is a temperature sensor installed between the return pipe 3a, near the inlet of the hot water tank 2, and at the bottom of the hot water tank 2. The antifreeze pipe 18 is a three-way valve that is a switching valve provided at the branch part of the pipe 3a and the antifreeze pipe 17, and the control device 12 is a conventional one shown in FIG. It is configured to operate based on the detection signal from the temperature sensor 16 in addition to the functions of the device.

The apparatus of the embodiment configured as described above normally performs the same operation as that shown in FIG. 1 described above. The temperature sensor 16 is used to prevent freezing of the pipes 3a and 3b. That is, the piping 3a, 3b
The temperature sensor 16 detects the water temperature between the suction port of the circulation pump 4, which has the lowest temperature, and the connection part 8a of the water supply pipe 8, and sends this detection signal to the control device 12, so that the detected water temperature is lower than the set value. When , the control device 12
to drive the circulation pump 4. At this time, the three-way valve 18
The normal AB connection is changed to AC connection, and the cold water in the pipes 3a and 3b flows into the bottom of the hot water tank 2 through the routes of the pipe 3b, the heat pump 1, the pipe 3a, and the antifreeze pipe 17, and the water in the hot water tank 2 is Warm water from the dead zone below the water level B level below the communication section of the outgoing pipe 3b is introduced into the pipes 3a and 3b. By driving the circulation pump 4 for a certain period of time, part or all of the cold water in the pipes 3a and 3b is replaced with hot water in the lower part of the hot water tank 2, and the circulation pump 4 is stopped. The circulation pump 10 on the load side continues to operate during the time when there is a hot water supply load, so that the hot water in the hot water storage tank 2, including a part of the lower dead area, has an almost uniform temperature. In this state, even if the anti-freezing exercise using the warm water in the dead area at the bottom of the hot water tank 2 according to this embodiment is performed, the cold water in the pipes 3a and 3b will mix with the hot water in the hot water tank 2, The hot water temperature will drop to some extent. However, by stopping the circulation pump 10 on the load side during periods when there is no load, a temperature distribution occurs in the hot water in the hot water tank 2, and the hot water in the lower part is lower than the hot water in the upper part. The water in the dead area within 2 can be effectively used for freezing prevention. Therefore, it is preferable to perform the above-described anti-freezing exercise only while the load-side circulation pump 10 is stopped. Note that while the circulation pump 10 on the load side is stopped, performing the thermal insulation operation of the hot water storage tank 2 by detecting the temperature of the temperature sensor 14 provided at the bottom of the hot water storage tank 2 as described above will lead to heat loss. If the above-mentioned anti-freezing exercise is carried out during this time without the hot water tank 2 being kept warm, it is possible to carry out the anti-freezing exercise even more economically.

In the above-described embodiments, a heat pump device for supplying hot water has been described, but the present invention can also be applied to a heat pump device that serves both heating and cooling, and heating and cooling as well as hot water supply.

Further, the switching valve may be replaced by two two-way valves instead of the three-way valve 18, and the same operation as described above may be performed.

〔Effect of the invention〕

As explained above, according to the present invention, the water temperature is detected by the temperature sensor at the lowest temperature part in the piping, the circulation pump is driven by the control device,
The switching valve is opened to the antifreeze piping side, and warm water from the dead area at the bottom of the hot water storage tank is used to prevent water from freezing in the piping that circulates water, eliminating unnecessary heat loss and increasing reliability. The effect is that it is possible to provide an antifreeze device that can be used as a control device with high performance.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing a conventional hot water supply heat pump device, and FIG. 2 is a configuration explanatory diagram showing a hot water supply heat pump device equipped with a freezing prevention device according to an embodiment of the present invention. 1...Heat pump, 2...Hot water tank, 3a, 3
b...Piping, 3b ₁ ...Suction side piping, 4...Circulation pump, 5...Municipal water intake, 6...Solenoid valve, 7...
Electric valve, 8...Water supply piping, 8a...Connection part, 1
2...Control device, 16...Temperature sensor, 17...
Freeze prevention piping, 18...3-way valve (switching valve). Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A heat pump and a hot water storage tank, two piping consisting of an outgoing path and an incoming path that communicate with these and circulate water, and a system provided in these piping and in the outgoing circulation path from the hot water storage tank to the heat pump. In a heat pump device equipped with a circulation pump and a water replenishment pipe that allows city water to flow into the suction side pipe of the circulation pump via a solenoid valve and an electric valve with adjustable flow rate, hot water is stored from the heat pump in the pipe that circulates water. Freezing prevention piping that communicates with the bottom of the hot water storage tank via a switching valve near the hot water storage tank entrance in the return piping to the tank, the part where the water supply piping connects to the suction side piping of the circulation pump, and the circulation pump suction port. and a control device that opens a switching valve on the antifreeze pipe side and drives the circulation pump for a certain period of time when the water temperature detected by the temperature sensor is below a set value. A freezing prevention device for a heat pump device, characterized by: 2. When the temperature sensor falls below the set value while the circulation pump on the load side is stopped, the control device opens the switching valve on the anti-freeze piping side to drive the circulation pump and shut down the water in the piping that circulates water. The antifreeze device for a heat pump device according to claim 1, wherein the water is exchanged with warm water in the lower part of the hot water storage tank. 3 The control device operates the heat pump using a temperature sensor installed in the hot water storage tank to keep the water temperature in the hot water storage tank above a certain value. The antifreeze device for a heat pump device according to claim 2, wherein the antifreeze device is configured to replace hot water with hot water. 4. The antifreeze device for a heat pump device according to claim 1, 2, or 3, wherein the switching valve is a three-way valve provided at a branching point between a pipe for circulating water and a pipe for preventing freezing.