JPH0335592B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an evaporator used in air conditioners, refrigerators, and the like.

Conventional technology During heating operation of a heat pump air conditioner that uses air as a heat source, the outdoor heat exchanger functions as an evaporator, and when the ambient air temperature drops, the evaporation temperature drops to 0°C or less, causing water vapor in the air to adhere as frost. Forms a layer of frost. Defrosting is necessary because the amount of heat exchange is significantly reduced due to the reduction in the amount of air passing through the frost layer and the heat insulation effect.

Therefore, the conventional evaporator, as shown in Figure 5,
It consists of a tube group 2 installed horizontally, through which refrigerant flows in the direction of arrow 1, and fin groups 4 and 5 inserted vertically into this tube group 2 at regular intervals, through which air flows in the direction of arrow 3. The fin spacing of the fin group 4 on the inflow side is arranged wider than that of the fin group 5 on the outflow side.

Problems to be Solved by the Invention Due to such a configuration, it was expected that the operation time would be lengthened until the space between the fin groups 4 on the air inlet side, where the amount of frost formation is the largest, is blocked by a layer of frost. However, the downstream fin group 5, where the fin spacing is narrower, is more likely to be blocked by the frost layer, and the overall operating time is not so long. Furthermore, when functioning as a condenser during cooling operation, the amount of heat exchange is insufficient because the heat transfer area is small.

The present invention solves the above-mentioned drawbacks of the prior art and provides an evaporator that can extend the operating time during frosting.

Means for Solving the Problems The evaporator of the present invention is composed of a heat exchanger consisting of a group of tubes and a group of fins, and a group of thermoelectric panels installed on the windward side of the heat exchanger.

Effect The effect of this technical means is as follows.
Ambient air passes through the thermoelectric panels before entering the heat exchanger. In thermoelectric panels, water vapor in the air is condensed into water or frost on the cooling surface due to the Peltier effect, and latent heat is also absorbed. The heat radiation surface radiates the heat absorbed by the cooling surface and warms the air flowing into the heat exchanger. That is, the thermoelectric panel group can act as a heat pump for the air heat source, converting latent heat in the air into sensible heat, and causing it to flow into the heat exchanger.

Therefore, in the heat exchanger, frost does not adhere to the heat transfer surface and the space between the fins is not blocked by a layer of frost, and the heat exchanger can absorb the total amount of heat in the air. In addition, even if frost should adhere to the heat transfer surface of the heat exchanger, the temperature of the cooling surface of the thermoelectric panel group is lowered to bring the air flowing into the heat transfer surface into a lower temperature and dry state. can be removed.

The frost layer formed on the cooling surface of the thermoelectric panel group can be easily melted by switching the current direction.

From the above, continuous operation can be achieved even under conditions where frost formation occurs.

Embodiment An embodiment of the present invention will be described based on FIGS. 1 to 4. FIG. 1 is an overall view, FIG. 2 is a detailed view, FIG. 3 is a detailed view of the thermoelectric panel, and FIG. 4 is a control block diagram.

As shown in FIGS. 1 and 2, the evaporator 6 of this embodiment is a heat exchanger consisting of a tube group 8 through which the refrigerant flows in the direction of the arrow 7 and a fin group 9 inserted into the tube group 8. 10, Air between the fin groups 9 arrow 11
It consists of a blower 12 that causes the flow to flow in the same direction, and a group of thermoelectric panels 13 installed on the windward side of the heat exchanger. And the thermoelectric panel group 13 has a cooling surface 14
(shown with diagonal lines) and heat dissipation surfaces 15 are arranged at regular intervals so as to be parallel to the airflow, and in groups arranged perpendicular to the airflow, adjacent surfaces are either cooling surfaces 14 or heat dissipation surfaces 15. In addition, in the group arranged parallel to the airflow, the cooling surfaces 14 are arranged on the windward side and the heat radiation surfaces 15 are arranged on the leeward side, so that they are arranged alternately (in this example, two rows are arranged in the airflow direction). be).

Note that 16 is a casing that supports the evaporator 6 and the blower 12, and 17 is a side plate for the heat exchanger 10.
As shown in FIG. 3, each of the thermoelectric panel groups 13
The thermoelectric element 18 is sandwiched between the cooling surface 14 and the heat radiation surface 15, and the cooling surface 1 is
4 absorbs heat, and the heating surface 15 releases the amount of heat absorbed and the amount of heat equivalent to the electrical input. As shown in FIGS. 2 and 4, the thermoelectric panel group 13 is controlled by the signal of the sensor 19 installed between the four adjacent thermoelectric panel groups 13 in the direction perpendicular and parallel to the airflow. External temperature and frost detection unit 20
Based on the signal from the evaporation temperature detection unit 22 which receives the signal from the sensor 21 installed at the bend part of the tube group 8, the temperature control circuit 23 determines whether frost formation occurs on the heat exchanger 10 or whether the thermoelectric panel group 13 has a frost layer. A signal is sent to the thermoelectric panel control circuit 24 to control whether or not the thermoelectric panel group 13 is energized, the amount of energization, and switching of the current direction.

Next, the operation of the configuration of this embodiment will be explained.

First, the air flowing into the evaporator 6 is dehumidified by condensing water vapor in the thermoelectric panel group 13, for example, if the windward side is surrounded by a cooling surface, and the leeward side is surrounded by a heat radiation surface. There, it is heated and flows into the heat exchanger 10. That is, latent heat in the air is converted into sensible heat by the heat pump action of the thermoelectric panel group 13, and dry air flows into the heat exchanger 10. Therefore, in the heat exchanger 10, frost does not adhere to the heat transfer surfaces of the tube group 8 or the fin group 9 and the space between the fins is not blocked by a layer of frost, and the total amount of heat in the air can be absorbed.

Further, the frost layer formed on the cooling surface 14 of the thermoelectric panel group 13 can be melted and dropped by switching the current direction of the thermoelectric panel group 13 and making the cooling surface 14 a heat radiation surface. During this time, the frost-free back side (windward side) acts as a cooling surface, and the leeward side panel acts as a heat dissipation surface, so air flow is unobstructed.

From the above, continuous operation can be realized even under conditions where frost formation occurs on the heat exchanger 10.

Furthermore, since the thermoelectric panel group 13 is installed on the windward side of the heat exchanger 10, the electrical input is also limited to the heat radiation surface 1.
5 to the air, energy loss is small and energy can be saved.

In addition, the sensor 19 typically detects the outside temperature;
When a frost layer grows on the cooling surface 13 of the thermoelectric panel group 13 and begins to bury the sensor 19, the frost layer temperature is detected, so one sensor can detect two temperatures and the thermoelectric panel group 13 can be accurately controlled.

In this embodiment, the thermoelectric panel groups 13 are arranged in a grid pattern, but the same effect can be obtained even if they are arranged in a staggered manner.

Effects of the Invention As described above, the evaporator of the present invention is composed of a heat exchanger consisting of a group of tubes and a group of fins, and a group of thermoelectric panels installed on the windward side of this heat exchanger, and realizes continuous operation even under frost conditions. Moreover, it is also energy efficient.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an evaporator according to an embodiment of the present invention;
Figure 2 is a detailed view of the main parts of the evaporator, Figure 3 is a detailed view of the thermoelectric panel of the evaporator, Figure 4 is a control block diagram of the thermoelectric panel group, and Figure 5 is the configuration of the conventional evaporator. It is a diagram. 6... Evaporator, 10... Heat exchanger, 8... Tube group, 9... Fin group, 13... Thermoelectric panel group, 1
4... Cooling surface, 15... Heat radiation surface, 19, 21...
temperature sensor.

Claims (1)

[Scope of Claims] 1. A heat exchanger consisting of a group of tubes through which a refrigerant flows, a group of fins inserted into this group of tubes and through which air flows, and 2. When the thermoelectric panel on the windward side is a heat dissipation surface, the thermoelectric panel on the leeward side is a cooling surface, and conversely, when the thermoelectric panel on the windward side is a heat dissipation surface, the thermoelectric panel on the windward side is a cooling surface. The evaporator is configured so that when the thermoelectric panel on the leeward side is the cooling surface, the thermoelectric panel on the leeward side is the heat dissipation surface. 2. The evaporator according to claim 1, wherein the thermoelectric panel is energized based on either outside air temperature or evaporator temperature. 3. The evaporator according to claim 1, characterized in that when frost formation on the thermoelectric panel is detected, the direction of energization to the thermoelectric panel is reversed.