JPS6353456B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims at high efficiency and energy saving in a heat pump device using a non-azeotropic mixed refrigerant, in combination with improvements to the refrigeration cycle.

Conventionally, in a heat pump device using a non-azeotropic mixed refrigerant, in a refrigeration cycle in which a compressor, a condenser, a throttle device, an evaporator, etc. are simply connected, the heated fluid and the heat source are connected to the condenser and evaporator. It has been implemented to reduce irreversible loss in the heat exchange process and increase efficiency by exchanging heat between the fluid to be cooled and the non-azeotropic mixed refrigerant in countercurrent flows.

In addition, by increasing the efficiency, the temperature rise of the heated fluid and the temperature drop due to the condensation process of the non-azeotropic mixed refrigerant, and the temperature drop of the cooled fluid and the temperature rise due to the evaporation process of the non-azeotropic mixed refrigerant are made to match as much as possible. The effect is said to be great. However, when the heated fluid of such a heat pump device is used for hot water supply, the outlet temperature of the heated fluid is preferably 70 to 80°C, the inlet temperature is usually 20 to 30°C (for example, tap water), and the temperature of about 50 deg. To reduce the irreversible loss using a non-azeotropic mixed refrigerant, it is desirable to mix refrigerants with a boiling point difference of about 150 degrees. On the other hand, it is extremely difficult to find a suitable combination of halogenated hydrocarbons (hereinafter referred to as fluorocarbons) that are actually suitable for refrigeration cycles due to factors such as critical temperature, critical pressure, and specific heat. This means that the effect of reducing irreversible loss is also reduced.

The present invention eliminates the drawbacks of the heat pump device described above, and will be described in detail below along with examples.

FIG. 1 shows an embodiment of a heat pump device using a non-azeotropic mixed refrigerant, which is an embodiment of the present invention, in which 1 is a compressor, 2 is a first condenser, and 3 is a gas-liquid separator. When a non-azeotropic mixed refrigerant is used, the liquid phase side contains more high boiling point refrigerant, and the gas phase side contains more low boiling point refrigerant. Reference numeral 4 denotes a second condenser connected to the top of the gas-liquid separator 3, that is, the gas phase part, in order to liquefy the gas-phase components, and its outlet merges with the liquid phase outlet of the gas-liquid separator 3. . 5 is a throttle device, 6 is an evaporator, and 7 is an accumulator, the outlet of which is connected to the suction port of the compressor 1.

Here, the fluid to be heated is in the condensers 2 and 4.
Heat is exchanged in the order of the second condenser 4 and the first condenser 2 so as to create counterflow in each condenser.

Next, the operation of the above-described embodiment will be explained with reference to the graph of low boiling point refrigerant concentration versus temperature at constant pressure shown in FIG. In FIG. 2, for convenience of explanation, graphs of constant condensation pressure and evaporation pressure are arranged vertically. Points a to h shown in the upper part of FIG. 2 correspond to the pressure, temperature, and concentration at points a to h of the example in FIG. That is, point a
-b is the condensation process of the first condenser 2, and since a non-azeotropic mixed refrigerant is used, a decrease in temperature is observed.
Points c and d are state points of the gas phase and liquid phase separated by the gas-liquid separator 3. Points c to e are the condensation process of the second condenser 4, which contains more low-boiling point refrigerant, so the temperature decreases to a temperature level closer to that of the first condenser 2, although the condensation pressure is the same as that of the first condenser 2. .
Points f to g are the expansion process of the expansion device 5, which can bring about a pressure drop from the condensing pressure to the evaporation pressure, as well as a temperature drop. Points g to h are the evaporation process of the evaporator 6, and a temperature rise is observed in contrast to the condensers 2 and 4. Points h to a are the compression process by the compressor 1, in which the refrigerant is compressed from evaporation pressure to condensation pressure.

Therefore, the feature of the present invention is that, as shown by the broken line in the upper part of FIG. By exchanging heat with the refrigerant, it is possible to reduce the temperature difference between the heated fluid and the refrigerant over a wide temperature range, thereby reducing irreversible loss. In particular, since heat is effectively recovered from the condensation process at points ce to e, there is no need to find a combination of refrigerants with a large boiling point difference as in the heat pump water heater described above, and it is not necessary to find a combination of refrigerants with a boiling point difference of about 30 to 100 degrees. Combinations become preferred, and it becomes easier to find these combinations among fluorocarbons. Also, although point d is in a saturated liquid state, the second
It is an easy design problem to configure the condenser 4 so that its outlet point e is supercooled and the confluence point f of the high-pressure liquid is also supercooled. This has the advantage that there is no need to provide a special in-cycle heat exchanger (not shown) or the like to bring about supercooling at the inlet of the throttling device 5 in order to prevent this.

In the embodiment shown in FIG. 1, the first and second
Although the condensers 2 and 4 were explained as separate units,
By having an integrated configuration, not only can a simple device be constructed, but also the evaporator 6
Also, by exchanging heat with the fluid to be cooled in a counterflow, irreversible loss can be reduced, and it can be used for purposes such as air conditioning.

Furthermore, when the heated fluid of the heat pump device of the present invention is used at a high temperature level such as for hot water supply, from the viewpoint of pressure resistance of the equipment, etc., the combination of non-azeotropic refrigerants should be chlorodifluoromethane ( Freon 22,
(boiling point -41℃) and a higher boiling point, preferably with a boiling point difference of about 30 to 100 degrees, and preferably about 40 to 100 degrees to avoid negative pressure in the equipment.
Freon with a boiling point difference of 80deg, specifically 1,2-dichlorotetrafluoroethane (Freon 114, boiling point 4℃), dichlorofluoromethane (Freon 21, boiling point 9℃), trichlorofluoromethane (Freon 11,
(boiling point: 24°C) is preferred.

As explained above, the heat pump device according to the present invention can be used in a refrigeration cycle using a non-azeotropic mixed refrigerant, from a compressor, a first condenser, a gas-liquid separator, a second condenser, a throttling device, an evaporator, etc. The component containing a large amount of low boiling point refrigerant separated by the gas-liquid separator is introduced into the second condenser, and the fluid to be heated flows in the second condenser and first condenser in that order, and in each condenser, flows in counterflow. By configuring the system to allow heat exchange, it is possible to achieve high efficiency and energy saving with a relatively simple configuration, and especially when the fluid to be heated is used at a high temperature level such as for hot water supply, it is possible to achieve high efficiency and energy saving. This also has the effect of making it easier to combine boiling refrigerants.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of a heat pump device according to an embodiment of the present invention, and FIG. 2 is a diagram showing a low boiling point refrigerant concentration versus temperature for explaining each state point of the heat pump device shown in FIG. FIG. DESCRIPTION OF SYMBOLS 1... Compressor, 2... First condenser, 3... Gas-liquid separator, 4... Second condenser, 5... Throttle device, 6... Evaporator.

Claims (1)

[Claims] 1. Using a non-azeotropic mixed refrigerant, a compressor, a first condenser, a gas phase part of a gas-liquid separator, a second condenser, a throttle device, and an evaporator are connected in order in an annular manner, The liquid phase part of the gas-liquid separator is connected between the outlet side of the second condenser and the expansion device to form a refrigeration cycle, and the heated fluid is passed through the second condenser and then the first condenser. A heat pump device in which the second condenser and the first condenser are placed close to each other, and the second condenser and the first condenser are arranged in close proximity to each other so as to exchange heat so as to have counterflow in each condenser. 2. The heat pump device according to claim 1, wherein the first and second condensers are integrated. 3. The heat pump device according to claim 1 or 2, wherein chlorodifluoromethane and a second fluorocarbon having a higher boiling point are mixed as a non-azeotropic refrigeration combination.