JPH0412385B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a frosting and icing prevention device for an air source heat pump.

Among various air conditioning heat source devices, the energy saving properties of heat pumps are being reconfirmed.

Among compression heat pumps, air source heat pumps are sold as products that use the infinite amount of air as a heat source, but during the harsh winter months, ice and frost build up on the heat extraction section from the air, resulting in a decrease in capacity. , various defrosting methods have been developed because of the increase in power.

However, during this defrosting period, the heating capacity is interrupted or reduced, and generally there is wasted energy input required for defrosting, so the overall efficiency is generally low.

As a means to eliminate this drawback, a method has been devised to prevent the formation of frost and ice by spraying antifreeze on the outside air side air heat exchanger. It had the disadvantage of absorbing moisture, causing a decrease in concentration, and eventually causing icing. Replenishing concentrated antifreeze in response to a decrease in antifreeze concentration is one solution, and this can be said to be an existing technology. However, if the antifreeze solution is simply replenished, the liquid level in the antifreeze tank in the air heat exchanger section will continue to rise, and in some cases, the antifreeze solution may overflow, which not only causes the antifreeze solution to be wasted, but also has a negative impact on the environment.

SUMMARY OF THE INVENTION An object of the present invention is to provide an efficient device for preventing frost formation and icing on an air heat exchanger on the outside air side, which eliminates the drawbacks of the above-mentioned conventional air source heat pumps.

The present invention relates to an air source heat pump equipped with a means for spraying antifreeze to the heat exchange element on the outside air side. The heat source heat pump is provided with a heating means for heating the antifreeze to evaporate water in the antifreeze, and a liquid level controller for detecting the antifreeze liquid level in the outside air side heat exchanger and controlling the antifreeze heating means, The air source heat pump is characterized in that the controller detects a rise in the level of the antifreeze liquid and energizes the heating means for the antifreeze liquid, and deenergizes the heating means for the antifreeze liquid when the liquid level of the antifreeze liquid drops.

The second invention of the present application is an air source heat pump equipped with a means for dispersing antifreeze to the heat exchange element of an outside air side heat exchanger, which is provided with a heating means for heating the antifreeze to evaporate water in the antifreeze, and an antifreeze replenishing means; Equipped with an antifreeze concentration detector and an antifreeze level detector on the outside air side heat exchanger, the antifreeze level detector detects a drop in the liquid level, and the antifreeze concentration detector detects that the antifreeze concentration has become diluted. This air source heat pump is equipped with a control device that adds antifreeze from an antifreeze replenishment tank to the antifreeze in the outside air side heat exchanger when the antifreeze replenishment occurs.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a flow sheet showing the area around the outside air side heat exchanger of an air source heat pump.

In the outside air side heat exchanger 1 of the heat pump, a refrigerant pipe 2 of the heat pump is guided inside a container-shaped outer skin 4 via a pressure reducing valve 3, and the refrigerant pipe 2 is communicated with a heat exchange element 6. A fan 7 is provided at the upper opening of the outer skin 4, and the fan 7 is covered by a rain shield 8. The fan 7 sucks in outside air from between the rain shield 8 and the opening at the top of the outer skin 4 and heats the internal refrigerant through the heat exchange element 6 during the winter. The outside air then returns to the outside air side through a looper 9 provided on the outer skin 4 as shown by arrow A in the figure. The bottom of the outer skin 4 is a reservoir of antifreeze 11, and the antifreeze mainly passes through a pipe 24 and a suction pipe 10 and is sucked by an antifreeze spraying pump (hereinafter referred to as pump) 12, but some of it passes through a pipe 13 and a stop valve. Warmer 1 through 14
Enter 5.

Note that the antifreeze reservoir is not limited to the bottom of the outer skin 4, but may be a separate tank installed in parallel.

The warmer 15 is equipped with an electric heater 16 in a closed container, and the antifreeze is heated by the warmer 15, and the water contained therein is evaporated and discharged as water vapor from the exhaust pipe 17 at the upper part. The antifreeze heated by the warmer 15 exits from the warmer 15 to the pipe 18 and is squeezed by the orifice 19 so as to fill the warmer 15 with the antifreeze.
It then joins the main flow of antifreeze flowing through the piping 24 via the stop valve 20 and passes through the suction pipe 10 to the pump 1.
Sucked into 2.

The antifreeze discharged by the pump 12 passes through the discharge pipe 21 and is sprayed onto the heat exchange element 6 by the sprayer 22 disposed in the upper part of the outer skin 4, and adheres to the surface of the heat exchange element 6 to cause frost formation and icing. It is designed to prevent this from accumulating in the reservoir at the bottom.

The specified liquid level of the antifreeze 11 in the reservoir at the bottom of the outer skin 4 is detected by a liquid level controller 30, and the signal is used to turn on/off the electric heater switch 16a and to control the automatic valve 31 via the concentration controller 28. There is.

A pipe 23 branched from the discharge pipe 21 is connected to the bottom of the outer skin 4 and the suction pipe 10 or pipe 24 of the pump 12. A stop valve 25 and a concentration detector 26 are provided in the pipe 23. When detecting the concentration of antifreeze, when the stop valve 25 is opened, a portion of the antifreeze discharged from the pump 12 flows from the pipe 23 to the pipe 24, from the pipe 24 to the suction pipe 10, and is sucked into the pump 12 and sent to the discharge pipe. 21 to pipe 23.

In this way, the concentration of the antifreeze that passes through the concentration detector 26 is detected, and the signal is converted to voltage by the converter 27, voltage amplified, and power controlled to be sent to the controller 28.
At the same time, it is sent to the concentration indicator 29 and displayed. When the concentration input by the controller 28 is below a set value and the liquid level controller 30 outputs a signal indicating that the water level of the antifreeze 11 is below a specified value, the controller 28 opens the automatic valve 31. From the antifreeze replenishment tank 32 to the stop valve 2
3. A piping 34 is provided so that the antifreeze liquid 11 in the outer skin 4 can be rapidly passed through the piping 34 through an automatic valve 31.

The electric heater 16 is controlled by the liquid level controller 3 when the water level of the antifreeze 11 in the reservoir of the outer skin 4 rises above a specified water level as detected by the controller 30.
0, the electric heater switch 16a is turned on, or the electric heater switch 16a is turned on via the controller 28 in response to a signal from the concentration detector 26 indicating that the antifreeze concentration has decreased. The electric heater switch 16a is turned off when the antifreeze level drops, or the electric heater switch 16a is turned off via the controller 28 in response to a detection signal from the concentration detector 26 when the antifreeze concentration rises. .

Next, the effects of the present invention will be described.

The portion of the antifreeze in the pool of the outer skin 4 that flows out to the piping 13 by the pump 12 is transferred from the piping 13 to the stop valve 14.
→ warmer 15 → piping 18 → orifice 19 → stop valve 20 → and merges with the main flow of antifreeze from piping 24 that sucks out antifreeze 11 in the pool of outer skin 4.
Suction pipe 10 → pump 12 → discharge pipe 21 → spreader 2
2 → heat exchange element 6 → antifreeze fluid 11 pool in outer skin 4 and circulates therein. While the moisture in the air flows from the sprayer 22 to the heat exchange element 6 to the pool of antifreeze 11 in the outer skin 4, the antifreeze is diluted by the moisture adhering to the sprayer 22 and the moisture in the air. And the volume of antifreeze increases.

When the liquid level controller 30 detects a rise in the liquid level, the liquid level controller 30 turns on the electric heater switch 1.
6a, the water is evaporated in the warmer 15 using the difference in evaporation temperature between the antifreeze and water, and the water is discharged from the exhaust pipe 17. It is sent out to the outlet side piping 18. Therefore, the antifreeze flowing in from the pipe 24 and the pipe 1
The thickened antifreeze flowing in from 8 is in the suction pipe 10 at a higher concentration than the antifreeze 11 in the reservoir of the outer skin 4, and is sucked into the pump 12 and discharged, so that the concentration is recovered from the sprayer 22. Antifreeze is sprayed.

The liquid level of the antifreeze liquid 11 in the reservoir of the outer skin 4 thus gradually decreases, and the liquid level controller detects this decrease in the liquid level and turns off the electric heater switch 16a.

The rise and fall of the liquid level of the antifreeze liquid 11 in the pool of the outer skin 4 detected by the liquid level controller 30 corresponds to the concentration of the antifreeze liquid. Therefore, if the concentration detector 26 detects that the antifreeze has a low concentration, the converter 2
7. Turn on the electric heater switch 16a via the controller 28, and when the concentration detector 26 detects that the antifreeze concentration has recovered to normal, turn off the electric heater switch 16a in the same way.

Antifreeze also evaporates as you drive, and gradually decreases. Therefore, before the liquid level controller 30 detects the highest liquid level of the antifreeze, when the concentration detector 26 detects that the antifreeze concentration has become below the set value of the concentration controller 28, the concentration controller 28
At the same time, the electric heater switch 16a is turned on and the automatic valve 31 is opened to send high-concentration antifreeze from the antifreeze replenishment tank 32 through the stop valve 33 and the automatic valve 31 to the piping 34 into the reservoir of the outer skin 4.

The liquid level of the antifreeze 11 in the reservoir of the outer skin 4 rises,
The pump 12 moves the sprayer 22 from the reservoir of the outer skin 4.
The concentration of antifreeze in the pipe sent to the tank gradually increases as moisture is further removed by the electric heater 16. The antifreeze in the pipe 23 branching off from the discharge pipe 21 is detected by the concentration detector 26 and sent to the concentration controller 28. When the detected antifreeze concentration reaches the set value, the controller 28 closes the automatic valve 31.
The electric heater 16 is turned off.

By replenishing the antifreeze, the liquid level of the antifreeze rises and when the liquid level controller 30 detects a high liquid level, the signal is sent to the controller 28.
On the other hand, in conjunction with the signal from the concentration detector 26 indicating that the concentration is below the specified concentration, the controller 28 activates the automatic valve 3.
Close 1. Since only the electric heater 16 is energized, the moisture in the antifreeze is removed. Then, when the liquid level of the antifreeze in the outer skin 4 falls and the antifreeze concentration still does not reach the set value, the controller 28 receives a signal from the concentration detector 26 by the same action and opens the automatic valve 31 to replenish the antifreeze. .

The control device of the embodiment described above will now be described. The control of the switch 16a by either the liquid level controller 30 or the concentration controller 28 will not be specifically explained because they are independent control devices, but an explanation diagram of the operation when the liquid level controller 30 and the concentration detector 26 are used together is shown below. Shown in Figure 2.

In liquid level detection, a signal is output at H level when the upper limit liquid level is detected, and the signal disappears when the upper limit liquid level is lowered. The concentration detector 26 is a light transmission type detector that photoelectrically converts transmitted light to detect the concentration. The liquid level controller 30 includes a liquid level detector and an amplifier, and constitutes a control device.

In FIG. 2, when the liquid level controller 30 detects a high liquid level, the relay coil 35 is energized, the contact 35-1 is closed, the electric heater 16 is energized, and the antifreeze is concentrated. When the liquid level controller 30 detects that the liquid level has fallen below the high level, the relay coil 35 is deenergized, the contact 35-1 is deenergized, and the electric heater 16 is turned off.

When the concentration detector 26 detects a low concentration, the relay coil 36 is energized, the contact 36-1 is closed, and the electric heater 16 is energized. When the concentration detector 36 detects an increase in the antifreeze concentration, the relay coil 36 is deenergized, the contact 36-1 is opened, and the electric heater 16 is turned off.

When the concentration detector 26 detects a low concentration and the liquid level controller 30 detects that the liquid level is falling, the relay coil 36 is energized and the contacts 36-
1 is closed and the electric heater 16 is energized, and at the same time, the contact 36-2 is closed and the normally closed contact 35-2 remains closed, so the stop valve 33 for replenishing concentrated liquid is opened and concentrated antifreeze is refilled. When the liquid level control 30 detects a high liquid level, the relay coil 35 is energized, the contact 35-2 opens and the stop valve 33 closes.
The electric heater 16 is energized, and the relay coil 35 is cut off due to a drop in the liquid level due to concentration of the antifreeze.
The contact 35-2 is closed, and the stop valve 33 for replenishing concentrated liquid is opened to replenish concentrated antifreeze. If the antifreeze concentration reaches the specified concentration before reaching the high liquid level, the relay coil 36 is deenergized and the contacts 36-1 and 3
6-2 is opened, the electric heater 16 is turned off, and the stop valve 3 is opened.
3 is closed.

In the above control, since antifreeze is an aqueous solution and the amount of solute generally decreases little, control by the liquid level controller 30 is normally performed repeatedly to maintain the liquid level, and the concentration control system is what works.

In the above explanation, installing an electric heater may seem to require a huge amount of electricity bill, but as an example of a trial calculation, suppose that a medium-sized air source heat pump, which absorbs 10 tons of moisture in one winter, Even if we assume that water can be expelled using only this electric heater, the cost is not that high, and considering that the intrusion of moisture is generally considered to be relatively small, this cost is even smaller, and the effectiveness of brine dispersion is much lower. It will not reduce the Note that the electric heater 16 was used in the embodiment. Although many heating means are conceivable, electric heaters are most preferred because they are safe, easy to handle, and do not require large equipment costs. The electric heater may be operated either for concentration detection or antifreeze tank liquid level detection, or in combination.
It is best to operate the heater automatically, but of course it is also possible to manually turn on the heater. Further, this heating source is not limited to the electric heater 16,
In general, any heating source such as gas combustion may be used.

In the embodiment, a detector for the concentration of the antifreeze used in the outside air side heat exchanger is provided to control the antifreeze heating means, so the concentration of the antifreeze is automatically adjusted.
There is no phenomenon of icing or frost forming on the heat exchange element due to dilution of the concentration of antifreeze. Moreover, the antifreeze solution will not be overconcentrated due to the heating device.

As described above, the present invention provides a heat pump device that is equipped with an antifreeze spraying device on an outside air side heat exchanger, and is equipped with an antifreeze heating means to heat the antifreeze to be sprayed to remove moisture from the antifreeze, and also provides an outside air side heat exchanger. Equipped with a liquid level controller that detects the liquid level of antifreeze in the container and controls the heating means, the antifreeze is maintained within a certain range and the antifreeze concentration is prevented from diluting, thus reducing the amount of water to the heat exchange element. icing,
Frost formation is prevented. The antifreeze heating means is equipped with an antifreeze temperature detector and an antifreeze level detector in the outside air side heat exchanger, and is further equipped with antifreeze replenishment means to detect low antifreeze level and dilution of the concentration. Since it is equipped with a control device that controls the antifreeze replenishment means, antifreeze shortages, antifreeze dilution, overconcentration, etc. do not occur over a long period of time. As a result of the above, the antifreeze concentration can be kept almost constant, so the amount of antifreeze to be circulated can be reduced and the device can be downsized.

[Brief explanation of drawings]

Figure 1 is a flow sheet of an embodiment of the present invention;
The figure is a control circuit diagram. 1... Heat exchanger, 2... Refrigerant piping, 3... Pressure reducing valve, 4... Outer skin, 6... Heat exchange element, 7... Fan, 8... Rain shield, 9... Looper, 11... Antifreeze, 12... Pump, 13... Piping, 14... Stop valve, 15... Warmer, 16... Electric heater, 1
6a... Switch, 17... Exhaust pipe, 18... Piping, 19... Orifice, 20... Stop valve, 21
...Discharge pipe, 22...Dispersion pipe, 23, 24...Piping, 25...Stop valve, 26...Concentration detector, 27
...Converter, 28...Controller, 29...Concentration indicator, 30...Liquid level controller, 31...
automatic valve, 32...tank, 33...stop valve, 34
...Piping, 35, 36...Relay coil, 35-
1, 35-2, 36-1, 36-2...Contact.

Claims (1)

[Scope of Claims] 1. In an air source heat pump equipped with a means for spraying antifreeze onto the heat exchange element of a heat exchanger on the outside air side, a heating means for heating the antifreeze to evaporate water in the antifreeze is provided, and a heat exchanger on the outside air side The liquid level controller detects the antifreeze liquid level in the heat exchanger and controls the antifreeze heating means, and the liquid level controller detects a rise in the antifreeze liquid level and energizes the antifreeze heating means to increase the temperature of the antifreeze liquid. An air source heat pump characterized by deenergizing the antifreeze heating means when the liquid level drops. 2. In an air source heat pump equipped with a means for spraying antifreeze onto the heat exchange element of the outside air side heat exchanger, a heating means for heating the antifreeze to evaporate water in the antifreeze is provided, as well as antifreeze replenishment means and antifreeze concentration detection. When the antifreeze level detector detects a drop in the liquid level and the antifreeze concentration detector detects that the antifreeze concentration has become thin, the antifreeze An air source heat pump equipped with a control device that adds antifreeze from a replenishment tank to the antifreeze in the outside air side heat exchanger.