JPS60114647A - Antifreezer for heat pump unit - Google Patents

Abstract

PURPOSE:To prevent water in a pipe line from freezing by preventing heat loss as much as possible, by using some quantity of hot water from a hot water tank by opening a directional control valve to the side of a hot water tank by a signal from a temperature sensor which senses the lowest temperature in the part of a pipe line. CONSTITUTION:A temperature sensor 16 senses the water temperature between the suction port of a water circulation pump 4 and the connecting part 8a of a pipe line with a water feed pipe line 8, where the water temperature is the lowest in the pipe lines 3a and 3b. When the sensed water temperature is under the set value, the pipe line is prevented from freezing by circulating the remaining cold water out of the pipe line 3b, by driving a water circulation pump 4 by a signal from a controller 12. When the water temperature goes down under the secondary set value which is lower than the primary set value, a three-way valve 18 connects ports (a) to (b) and drives the water circulation pump 4 for a predetermined time. Hot water is fed into the pipe line 3b from the tank 2 and in the meantime, the water temperature reaches a set value for the temperature sensor 16. The time is to be determined as short as possible in order to prevent heat loss from hot water in the hot water tank 2. When the water temperature is heightened above the secondary set value, the three-way valve 18 is changed to connects ports (a) to (c), the pump 4 is driven for a predetermined time in order to circulate water bypassing the hot water tank 2.

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]

A 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 piping to the hot water storage tank 2, 3b is an outgoing piping to the heat pump 1, and piping 3a.

3b allows the heat pump 1 and the hot water storage tank 2 to communicate with each other. 4 is a circulation pump installed in the pipe 3b; 8 is a pipe connected to the suction side of the circulation pump 4 from the city water intake 5 via a solenoid valve 6 and an electric valve 7 capable of adjusting the flow rate; 10 and 11 are connected to the load side pipe 9; Circulation pump and faucet provided, 12
1 is a control device, 13 is a water level switch provided in the hot water storage tank 2, 14 is a temperature sensor provided at the bottom of the hot water storage tank 2, and 15 is a temperature sensor provided in the pipe 3a on the outlet side of the heat pump 1.

Next, the operation of the apparatus shown in FIG. 1 will be explained in detail. In this heat pump device for hot water supply, when the circulation pump 10 on the load side is constantly driven and hot water is used from the faucet 11, the amount of water that returns from the piping 9 on the load side to the hot water tank 2 decreases. The water level inside will drop 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 tank 2, city water is supplied from the intake port 5 to the water replenishment pipe 8.
Enter the solenoid valve 6. The hot water is sucked into the circulation pump 4 through the electric valve 7, through the connection part 8m, and the @-side piping ab1, sent to the heat pump IK, heated there, and supplied to the hot water storage tank 2 through the piping 3&. be exposed. At this time, the amount of make-up water is determined by the control device 12 based on the detection signal from the temperature sensor 15 so that the outlet water temperature of the heat pump 1 is constant, for example, 5°C.
Then, the motor-operated valve 7 whose opening degree is adjusted is operated and controlled. 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.
Further, as the temperature rises, the electric valve 7 gradually opens to increase the supply of city water. Then, the inflow water i to the heat pump 1
Since # is constant, the water for the shortage is supplied from the storage tank 2, mixed with supplied city water, and flows into the heat pump 1. 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. Circulation pump 4 stops. When the water temperature in the hot water storage tank 2 drops below a certain level, such as 50'C, due to heat loss while 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. The circulation pump 4 is driven to perform a heat retention operation.

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

However, when the conventional heat pump device for hot water supply configured as described above is installed in a cold region.

This invention solves the problem that the water in the pipes may freeze when the temperature of the water in the pipes suddenly drops due to a drop in the temperature of the hot water storage tank, or in the case of operation without heat retention. [Summary of the Invention] This invention and a control device having a temperature sensor that bypasses the hot water storage tank and detects the water temperature between the hot water tank inlet and suction port, and the control device causes the bypass pipe to be opened when the water temperature detected by the temperature sensor is below a set value. The water in the piping is circulated by bypassing the hot water storage tank, and when the detected water temperature is below a very low set value, the bypass pipe is closed and the hot water in the hot water storage tank is used to prevent freezing. It is an object of the present invention to provide a freeze prevention device for a heat pump device that can suppress the loss as much as possible 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 Figure 2, 1 is a heat pump, 2 is a hot water tank, 3 &
3b is the return pipe to the hot water storage tank 2, and 3b is the heap di-/p1
F/7'l&YoAm A JrLjl&FM y)
' Sob 5 is the city water intake, 6 is the solenoid valve, 7 is the electric valve that can adjust the flow rate, 8 is the water supply pipe, 8a is the connection part of the water supply pipe 8 to pipe 3b, 9 is the circulation on the load side 10 is a circulation pump on the load side, 11 is a faucet, 1.1; l is a water level switch, 14 and 15 are temperature sensors, and these have the same configuration as the conventional heat pump device described above. be. In addition, 16 is a temperature sensor installed on the suction side pipe ab1 between the connection part 8a of the water supply pipe 8 and the circulation pump 4 suction port, and 17 is a temperature sensor installed near the hot water storage tank 2 population of the pipe 3 and the hot water storage tank 2 outlet of the pipe 3b. A bypass pipe 18 is a three-way valve that is a switching valve provided at the branch of the pipe 3a and the bypass pipe 17, and the control device 12 is a conventional device shown in FIG. In addition to the functions of temperature sensor 16
It is configured to operate even with detection signals from.

The apparatus of the embodiment configured as described above is as described in the first example.
The operation is similar to that shown in the figure.

The antifreeze operation for piping 3m and 3b is performed by temperature sensor 1.
Do it in 6. That is, the temperature sensor 16 detects the water temperature between the suction port of the circulation pump 4, which has the lowest temperature among the pipes 3m and 3b, and the connection part 8& of the water supply pipe 8, and sends this detection signal to the control device 12. When the detected water temperature is below the first set value, the control device 12 drives the circulation pump 4. At this time, the three-way valve 18 is normally connected to &C, and the pipe 3a is connected.

pipe 3 without letting the cold water in 3b flow into the hot water tank 2.
&, heat pump 1. It is circulated through the pipe 3b and the bypass pipe 17. In this case, since the water in the pipe 3a is on the outlet side of the heat pump 1, the temperature is higher than that on the normal pipe 3b side, and by circulating the residual water in the pipe 3b, the water in the pipe is Freezing can be prevented. This circulation of water continues by turning the circulation pump 4 on and off until the water temperature in the pipes 3m and 3b gradually decreases and reaches a second set value that is lower than the first set value. When the temperature sensor 16 detects that the water temperature has fallen below the second set value and sends this detection signal to the control device 12, the control device 12 connects the three-way valve 18 to al+ and drives the circulation pump 4 for a certain period of time. do.

This fixed period of time allows the hot water in the hot water tank 2 to flow into the pipe 3b and reach the position of the temperature sensor 16, thereby suppressing the loss of hot water in the hot water tank 2 as much as possible.

When the hot water in the hot water tank 2 reaches the temperature sensor 16 and the water temperature exceeds the second set value, this is detected and the three-way valve 18 is switched to the Jle connection to mix the cold and hot water. The circulation pump 4 is driven for a certain period of time, and the hot water tank 2
〇In the above-mentioned embodiments, a heat pump device for hot water supply was explained, but this invention is applicable to heating.

It can also be applied to heat pump devices that serve both air conditioning, hot water supply, heating, and cooling.

Furthermore, the switching valve may be replaced by two three-way valves instead of the three-way valve 18 to perform the same operation as described above.

〔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 of the pipe, the circulation pump is driven by the control device, and the hot water storage tank is opened with the switching valve open to the bypass pipe side. By bypassing the water in the piping and circulating the water in the piping, only when the water temperature in the piping drops to a very low temperature, open the switching valve to the hot water tank side and use some of the hot water in the hot water storage tank. To prevent freezing,
The effect is that it is possible to provide an antifreeze device that eliminates wasteful heat loss and can perform highly reliable control.

[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 storage tank, 3a, 3b.
... Piping, 3b1... Suction side piping, 4... Circulation pump, 5... City water intake, 6... Solenoid valve, 7... Electric valve, 8... Water supply piping, 8a...Connection part, 12.
··Control device. 16...Temperature sensor, 17...Bypass pipe, 18.
...Three-way valve (switching valve). Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others)

Claims (3)

[Claims] (1) A heat pump and a hot water storage tank, piping that connects these and circulates water, a circulation bonder installed on one side of these piping, and a circulation pump that circulates city water via a solenoid valve and an electric valve that can adjust the flow rate. A heat pump device comprising: a water supply pipe that bypasses the hot water storage tank and communicates the pipes on the inlet side and the outlet side of the hot water storage tank via a switching valve; and the water supply pipe. has a temperature sensor that detects the water temperature between the part that connects to the suction side piping of the circulation pump and the circulation pump suction port, and when the water temperature detected by this temperature sensor is below a set value, a switching valve is opened on the bypass pipe side. Freezing of a heat pump device, characterized in that it is equipped with a control device that drives a circulation pump and further opens a switching valve on the hot water storage tank side for a certain period of time to drive the circulation pump when the detected water temperature is below a lower set value. Prevention device. (2) The control device opens the switching valve on the bypass pipe side if the water temperature detected by the temperature sensor exceeds a very low set value while driving the circulation pump with the switching valve open on the hot water storage tank side. The antifreeze device for a heat pump device according to claim 1, wherein the circulation pump is driven for a certain period of time and then stopped. (3) The antifreeze device for a heat pump device according to claim 1 or 2, wherein the switching valve is a three-way valve provided at a branch point between the hot water tank inlet side pipe and the bypass pipe.