JPH057632B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a frosting and icing prevention device for an air source heat pump.

[Conventional technology and its problems]

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

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 there is generally a waste of energy required for defrosting, so the overall efficiency is generally low.

As a means to eliminate this drawback, a method has been devised to prevent frost and icing by spraying antifreeze on the outside air side air heat exchanger, but antifreeze tends to concentrate in weather conditions with low outside air humidity. On the other hand, in weather conditions where the outside air humidity is high, such as rain or snowfall, the antifreeze solution gradually absorbs moisture from the air, resulting in a decrease in concentration, which eventually leads to 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.

[Purpose of the invention]

The present invention aims to effectively utilize heat in the means for evaporating moisture in the antifreeze in an air source heat pump equipped with a means for distributing antifreeze to an outside air side heat exchange element and a means for evaporating moisture in the antifreeze using an external heat source. The aim is to save the thermal energy required for heating.

[Structure of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 are flow sheets for an air source heat pump, showing the vicinity of the outside air side heat exchanger of the air source heat pump. FIG. 5 shows a conventional antifreeze concentration method using an external heating source, and FIGS. 1 to 4 show embodiments of the present invention.

First, the conventional technique will be explained based on FIG.

In the outside air side heat exchanger 1 of the heat pump, the refrigerant pipes 2 and 29 of the heat pump are guided into the inside of the container-shaped outer skin 4 via the pressure reducing valve 3.
is in communication with the 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 louver 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. It enters the warmer 15 through 14.

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 heating concentrator 15 has an electric heater 16 in a closed container.
Here, the antifreeze liquid is heated and concentrated, and the water content is evaporated and discharged as water vapor from the upper exhaust pipe 17. The antifreeze heated in the heating concentrator 15 exits to the pipe 18 and is throttled by the orifice 19 so as to fill the heating concentrator 15 with antifreeze.Then, the main stream of antifreeze flows through the pipe 24 via the stop valve 20. The water flows through the suction pipe 10 and is sucked into the pump 12.

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. On the other hand, the antifreeze solution is designed to accumulate in a reservoir at the bottom.

A specified liquid level of the antifreeze liquid 11 in the reservoir at the bottom of the outer skin 4 is detected by a liquid level controller 30, and the electric heater is turned on and off in response to a signal from the liquid level controller 30.

The electric heater 16 is controlled by turning on the electric heater by the liquid level controller 30 when the water level of the antifreeze liquid 11 in the reservoir of the outer skin 4 rises above the specified water level, which is detected by the controller 30.
When the level of antifreeze in the tank drops, the electric heater is turned off.

FIG. 1 shows an embodiment of the invention.

The water in the antifreeze that evaporated in the heating concentrator 15 enters the recovery heat exchanger 31 via the exhaust pipe 17, heats the hot water of the load side fluid, and condenses and liquefies it. The liquefied drain 39 is transferred to the drain pipe 3
2, the heat is discharged to the outside of the recovery heat exchanger.

FIG. 2 shows another embodiment.

In order to keep the internal pressure of the heating concentrator 15 below atmospheric pressure, an orifice 19 is provided in the antifreeze pipe 13 and an antifreeze pump 36 for heating and concentration is provided in the antifreeze pipe 18 to circulate the antifreeze. On the other hand, a gas exhaust pipe 33 and an exhaust pump 34 are provided to continuously or periodically exhaust the non-condensable gas (for example, air) accumulated in the heating concentrator 15 to the outside. The drain 39 condensed and liquefied in the recovery heat exchanger 31 passes through a drain pipe 32 for applying a liquid column by the pressure difference between the internal pressure of the recovery heat exchanger 31 and the outside pressure, and then flows to the hot water tank 41.
to be discharged. This drain 39 can be used as load-side hot water.

FIG. 3 shows another embodiment.

Antifreeze heat exchanger 37 is installed in antifreeze pipes 13 and 23.
The antifreeze flowing in and out of the heater exchanges heat with each other. On the other hand, the drain 39 condensed within the recovery heat exchanger 31 is discharged to the outside by the drain pump 35 via the drain pipe 32.

FIG. 4 shows the primary side drain piping 3 of the drain pump in order to discharge the non-condensable gas in the heating concentrator 15.
2 is provided with an ejector 40, and a drain pump 35 discharges non-condensable gas to the outside together with a drain 39.

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

The amount of antifreeze in the pool of the outer skin 4 that goes out to the piping 13 by the pump 12 is transferred from the piping 13 to the stop valve 1.
4 → heating concentrator 15 → piping 18 → 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, and then flows into suction pipe 1.
0→pump 12→discharge pipe 21→spreader 22→heat exchange element 6→reservoir of antifreeze 11 in outer skin 4. And the antifreeze is distributed by the sprayer 22 → the heat exchange element 6 →
Spreader 2 is installed between the pool and flow of antifreeze 11 in outer skin 4.
The volume of the antifreeze increases as it is diluted by the moisture attached to the antifreeze and the moisture in the air.

When the liquid level controller 30 detects a rise in the liquid level, the liquid level controller 30 turns on the electric heater, and uses the difference in evaporation temperature between antifreeze and water to evaporate water in the heating concentrator 15, and the water is exhausted. tube 1
7, the antifreeze liquid whose concentration has increased and whose volume has decreased is sent to the outlet side piping 18 of the heating concentrator 15. Therefore, the antifreeze fluid flowing in from the pipe 24 and the highly concentrated antifreeze fluid flowing in from the pipe 18 have a higher concentration in the suction pipe 10 than the antifreeze fluid flowing from the pipe 24, and are sucked into the pump 12 and discharged. The antifreeze solution whose concentration has been restored is sprayed from the sprayer 22.

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 switches off the electric heater.

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.

In addition, a heat exchanger 37 is used, and a heating concentrator 15 is used.
If the antifreeze flowing in and out of the
The lower antifreeze liquid is heated by the high-temperature antifreeze liquid discharged from the heating concentrator 15, and is raised to a temperature close to the evaporation temperature in the heating concentrator 15, and almost all the water contained in the antifreeze liquid is evaporated in the heating concentrator 15. All you have to do is input the latent heat. Although many heating means are conceivable, an electric heater is most preferable because it is safe, easy to handle, and does not require large equipment costs. The electric heater may be operated either by detecting the concentration or by detecting the liquid level in the antifreeze tank, or in combination. Automatic operation is best, 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, but may be any general heating source such as gas combustion.

On the other hand, the steam generated in the heating condenser 15 heats and condenses the load-side fluid hot water in the recovery heat exchanger 31. Therefore, most of the energy used to heat and concentrate the antifreeze liquid can be used to heat the load-side hot water. It has a double heating effect. Furthermore, heating concentrator 1
By keeping 5 and the recovery heat exchanger 31 in a vacuum below atmospheric pressure, it is easy to manufacture the container.
It also increases safety.

〔Effect of the invention〕

As described above, the present invention is a heat pump device equipped with an antifreeze spraying device on the outside air side heat exchanger, and is provided with a heating means to heat the antifreeze to be sprayed to remove moisture from the antifreeze. It is possible to prevent water from landing on the heat exchange element and frost formation due to a decrease in the concentration of water. Furthermore, since the thermal energy required to heat the antifreeze liquid is used to heat the load-side fluid, effective use of energy is achieved.

[Brief explanation of the drawing]

FIGS. 1, 2, 3, and 4 are flow sheets for explaining different embodiments of the outside air heat exchanger and the surrounding area of the air heat source heat pump of the present invention, and FIG. 5 is a flow sheet of the conventional air heat source heat pump. This is a flow sheet for explaining devices around an outside air heat exchanger of a heat pump. 1... Outside air side heat exchanger, 2... Refrigerant piping, 3... Pressure reducing valve, 4... Outer skin, 6... Heat exchange element, 7... Fan, 1
1... Antifreeze, 13... Piping, 14... Stop valve, 15...
Heating concentrator, 16... electric heater, 17... exhaust pipe,
18... Piping, 19... Orifice, 20... Stop valve,
21...Discharge pipe, 22...Spreader, 25...Compressor, 2
6...Load side heat exchanger, 27...Load side hot water pump,
31...Recovery heat exchanger, 32...Drain piping, 33...
Gas exhaust pipe, 34...exhaust pump, 35...drain pump, 37...antifreeze heat exchanger, 38...antifreeze heat exchanger coil, 39...drain, 40...ejector.

Claims (1)

[Scope of Claims] 1. An outside air side heat exchanger 1 which takes away heat from outside air and has a means for dispersing antifreeze onto a heat exchange element 6, and a compressor 25 which compresses the refrigerant heated and evaporated in the heat exchange element. In an air source heat pump equipped with a load-side heat exchanger 26 for heating a load fluid with gas discharged from the compressor, and a heating concentrator 15 for heating and concentrating the antifreeze liquid, during heating and concentration. An air source heat pump characterized in that a load fluid introduced into the load-side heat exchanger is heated with steam evaporated and separated from antifreeze. 2. Operate the heating concentrator below atmospheric pressure,
2. The air source heat pump according to claim 1, further comprising means for discharging condensate condensed when heating a load fluid with vapor evaporated and separated from antifreeze to the outside at atmospheric pressure. 3. The air heat source heat pump according to claim 1 or 2, wherein the heating concentrator is provided with a gas exhaust means. 4. The air source heat pump according to claim 3, wherein the drain discharge means and the gas discharge means can be used in common. 5. The air source heat pump according to claim 1, 2, 3, or 4, wherein heat is exchanged between antifreeze flowing in and out of a heating concentrator.