JPH02258467A - Vehicle heat pump air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a heat pump type air conditioner for a vehicle, and particularly to a dual use heat pump type air conditioner suitable for being mounted on a railway vehicle.

[Conventional technology]

Conventionally, the common structure of heat pump air conditioners is as follows:
As shown in FIG. 3, the compressor 1. Four-way switching valve2. Outdoor heat exchanger 3. Check valve 4, 7. Pressure reducing mechanism (expansion valve or capillary tube) 5, 8° receiver 6, indoor heat exchanger 9. It was a functional connection of saccharine accumulators 10.

In addition, as another configuration, as shown in FIG. 4, the compressor 1
．． Four-way switching valve2. Outdoor heat exchanger 3. Decompression mechanism 11. Indoor heat exchanger9. A configuration in which accumulators 10 are functionally connected is known. In addition, in FIGS. 3 and 4, solid line arrows indicate the flow of each refrigerant during cooling, and double-dot line arrows indicate the flow of each refrigerant during heating.

In these heat pump cycles, frost formation occurs on the outdoor heat exchanger during heating operation in winter, and this frost formation reduces the heating capacity, so defrosting operation is essential. During this defrosting operation, 11 cells could not be operated and the operating capacity was wasted. Therefore, a heat pump cycle having the following configuration has been developed for the purpose of suppressing frost formation on the outdoor heat exchanger and reducing the cooling power of the defrosting operation. This heat pump cycle has a compression of 8! as shown in Figure 5. l, four-way switching valve 2.
Outdoor heat exchanger 3. Decompression mechanism 11. It has a structure in which an accumulation receiver and an indoor heat exchanger 9 are functionally connected.

The installation of the accumulator (hill) made it possible to suppress frost formation.

That is, during the heating operation, as shown by the dotted line arrow in FIG. It exchanges heat with the air and liquefies, producing a heating effect. Then, the liquefied refrigerant enters the accumulator sheave portion t2m, and then enters the pressure reducing mechanism H.

In the process of passing through the pressure reducing mechanism, the liquid refrigerant is depressurized and expands adiabatically, and some of the refrigerant vaporizes and becomes a gas-liquid mixed refrigerant.
During operation of the L chamber, the heat enters the outdoor heat exchanger 3, which functions as an evaporator, where it pumps up heat while exchanging heat with the air. The refrigerant exiting the outdoor heat exchanger 3 passes through the four-way switching valve 2
The refrigerant passes through a separate circuit and enters the accumulator section 12b of the accumulator 12, where the liquid portion of the refrigerant is separated and only the gas refrigerant returns to the compressor l. Here, in order to suppress the frosting phenomenon, the pressure of the refrigerant in the outdoor heat exchanger 3, which is the aSS smoke evaporator, is increased to prevent evaporation. Increase the temperature
n can be decreased. For this purpose, heat is exchanged between the low temperature refrigerant in the accumulator section b of the accumulator 12 and the high temperature refrigerant in the receiver section 12a. By applying heat to the low-temperature refrigerant in this way, the suction pressure of the compressor is increased, and the evaporation pressure in the outdoor heat exchanger 3 is increased, thereby suppressing the 1F frost phenomenon.

[Problem to be solved by the invention]

In the above conventional technology, the accumulator and receiver are integrated to enable heat exchange between the refrigerants, which increases the overall size and may complicate the arrangement and piping connections within the air conditioner. . In particular, in recent years, there has been a fear that this will become a major hindrance to the progress of miniaturization of air conditioners.

An object of the present invention is to provide a heat pump air conditioner for a vehicle that can suppress frost formation and have a simplified structure.

[Means to solve the problem]

In order to achieve the above object, in a heat pump air conditioner, a heat source is installed in the accumulator to heat the refrigerant in the accumulator during heating operation.

[For production]

The heat source provided in one of the accumulators can heat the refrigerant in the accumulator during heating operation, thereby increasing the evaporation pressure in the outdoor heat exchanger, thereby suppressing the frost formation phenomenon χ in the outdoor heat exchanger. I can do it.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, the same reference numerals as in the conventional example indicate the same members. Compressor 1, four-way switching valve 2.
Outdoor heat exchanger 3. The basic cycle structure composed of the pressure reducing mechanism 11, the indoor heat exchanger 9, and the accumulator 10 is the same as that of the conventional example. 13 is accumulator 1
This is a heater that serves as a heat source attached to the side of the 0. 14
is a molded circuit breaker connected in series to the heater 13. Reference numeral 18 denotes a heating relay, to which the circuit breaker 17 is connected, and the heating relay 18 is energized based on the warm man command number. 15 is a heater relay, 1
6 is an outside temperature thermostat, and the heater relay 15
is excited while the outside temperature thermostuft 16 is closed. Here, the set value of the outside air temperature thermostat 16 is set to an outside air temperature at which frost phenomenon is likely to occur in the outdoor heat exchanger 3, for example, about 2°C to 3°C.

In such a configuration, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 during heating operation passes through the four-way switching valve 2 as indicated by the dotted line arrow, enters the indoor heat exchanger 9 that acts as a condenser, and exchanges heat with the air. It then liquefies and then performs the heating action.

The liquefied refrigerant enters the pressure reducing mechanism 11, is depressurized and expands adiabatically, and some of the refrigerant evaporates to become a gas-liquid mixed refrigerant and enters the outdoor heat exchanger 3, which acts as a YA device, where it exchanges heat with air. It pumps up heat while exchanging and vaporizing.

The refrigerant leaving the outdoor heat exchanger 3 passes through the square circuit of the four-way switching valve 2 and enters the 1-cumulator 10 . The accumulator 2
The refrigerant that has entered is heated by a heater 13 attached to the accumulator 2. By being heated in this way, the refrigerant returns to the compressor (its temperature rises, that is, its saturation pressure rises), which in turn causes the evaporation pressure of the refrigerant in the outdoor heat exchanger 3 to rise, resulting in an increase in outdoor heat. sfW to the exchanger 3 can be suppressed. By attaching the accumulator 2I ni-heater 13 in this manner, it is possible to obtain the same effect as a conventionally used accumulator receiver.

Next, to explain the control situation of the heater 13, the heating relay 18 has a circuit breaker 17 on its primary side, and the heating relay 18 is energized based on an ambiguity command. When heating relay 18 is energized, heater relay 15 is energized while outside temperature thermostat 16 is closed. Here, the set temperature of the outside air temperature thermostat J6 may be set to an outside air temperature of about 2 to 3 DEG C. at which frost formation is likely to occur. If the heater relay 15 is excited by the outside air temperature thermostat 161 due to a decrease in the outside air temperature, the heater 13 will be operated only as long as it is necessary to suppress frost formation, thereby effectively preventing frost formation.

According to such a configuration, it is possible to prevent frost formation on the outdoor heat exchanger 3 during heating operation, and it is possible to suppress a decrease in the 51 tlJ capacity due to the frost formation phenomenon. Also,
The frequency of load removal operation can be significantly reduced by 4 times,
It is possible to extend the heating operation time. Furthermore, compared to conventionally used accumulators, the overall structure can be made more compact, and the number of piping connected to the accumulator 10 is also smaller (compared to conventional accumulators). It is possible to simplify the following two ways.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to suppress the frost formation phenomenon and to simplify the structure.

[Brief explanation of drawings]

@ Figure 1 is a circuit diagram showing an embodiment of the heat pump type air conditioner according to the present invention, and Figure 2 is a circuit diagram showing the heat pump type air conditioner shown in Figure 1! Control circuit diagram of the heater in the device, Figures 3 and 4
1 and 5 are circuit diagrams showing a conventional heat-bon type air conditioner. l...Compressor, 2...Four-way switching valve, 3
...Outdoor heat exchanger, 9...Outdoor heat exchanger, 10...Accumulator, ■...
Decompression mechanism agent Patent attorney Katsuo Ogawa - Figure 1 Figure 2 Figure 3 '44 Figure

Claims (2)

[Claims] 1. Compressor, four-way switching valve, outdoor heat exchanger, pressure reduction mechanism,
A heat pump air conditioner for a vehicle comprising an indoor heat exchanger and an accumulator, wherein the accumulator is provided with a heat source that heats a refrigerant in the accumulator during heating operation. 2. Compressor, four-way switching valve, outdoor heat exchanger, pressure reduction mechanism,
A heat pump air conditioner for a vehicle comprising an indoor heat exchanger and an accumulator, characterized in that it is provided with a heating means that generates heat and heats the refrigerant in the accumulator when the outside air temperature falls below a set value. Heat pump type air conditioner.