Refrigeration – With internal-combustion engine
Reexamination Certificate
2001-07-26
2002-07-30
Tapoicai, William E. (Department: 3744)
Refrigeration
With internal-combustion engine
C062S244000
Reexamination Certificate
active
06425257
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an air conditioner, such as a gas engine heat pump, which uses hot water.
2. Description of the Related Art
A conventional air conditioner, which uses hot water, is shown in FIG.
5
. In
FIG. 5
, reference number
1
denotes an engine,
2
denotes a compressor,
13
denotes an outer heat exchanger for heat exchanging between outside air and a refrigerant,
21
denotes a radiator for radiating heat of an engine cooling water,
51
denotes an engine cooling water circuit in which the engine cooling water circulates, and
52
denotes a refrigerant circuit in which the refrigerant circulates. According to this air conditioner, the radiator
21
is interposed between the outer heat exchangers
13
and
13
; therefore, the refrigerant is vaporized using not only heat of the outside air but also the waste heat of the engine
1
. Moreover, such structure is called “radiator interposition structure” below.
In this air conditioner, the waste heat is conducted through fins provided with the radiator and through the air, and then it is recovered. Therefore, a portion of the waste heat of the engine
1
is discharged into atmosphere, and the waste heat cannot be utilized efficiently. Due to this, the refrigerant is vaporized sufficiently in the outer heat exchanger
13
when the temperature of the outside air is low, and heating capability of the air conditioner is affected by the temperature of the outside air.
Another conventional air conditioner is shown in FIG.
6
. In this air conditioner, the water heat exchanger
16
is connected in series to the outer heat exchanger
13
in the engine cooling circuit
51
and the refrigerant circuit
52
. Thereby, the waste heat of the engine
1
can be recovered by the water heat exchanger
16
, in addition to the radiator
21
. Moreover, such structure is called “water heat exchanger series structure” below. In this air conditioner, both the outer heat exchanger
13
and the water heat exchanger
16
resist the circulating refrigerant, and thereby the flow pressure loss of the refrigerant increases. Consequently, a large amount of refrigerant has to be contained in refrigerant circuit
52
.
Moreover, in the radiator interposition structure shown in FIG.
5
and the water heat exchanger series structure shown in
FIG. 6
, in order to increase heat recovered to the refrigerant, it is necessary to drive a fan
53
(in
FIG. 5
, but not shown in
FIG. 6
) for introducing the outside air using a lot of force. Consequently, the problem arises that increased electric power is required for the fan
53
and the fan
53
generates noise.
Therefore, an object of the present invention is to provide an air conditioner which can efficiently vaporize the refrigerant using the waste heat of the engine; which has a stable heating capability regardless of the temperature of the outside air; and which can decrease the electric power required for the fan and thereby decrease the noise due to the fan, in a heating operation.
SUMMARY OF THE INVENTION
In order to achieve the object, the present invention provides an air conditioner comprising:
a refrigerant circuit comprising a compressor for compressing a refrigerant; an outer heat exchanger for exchanging heat between the refrigerant and outside air; a restrictor for restricting the refrigerant flowing out from a water heat exchanger; and an inner heat exchanger for exchanging heat between inside air and the refrigerant;
an engine cooling water circuit comprising an engine for driving the compressor; and a radiator for exchanging heat between engine cooling water and outside air; and
a water heat exchanger for exchanging heat between the refrigerant circulating in the refrigerant circuit and the engine cooling water circulating in the engine cooling water circuit;
wherein an evaporator comprising the outer heat exchanger and the water heat exchanger connected in parallel to the outer heat exchanger, is provided in the refrigerant circuit.
According to the air conditioner, the outer heat exchanger and the water heat exchanger which is connected in parallel to the outer heat exchanger is provided in the refrigerant circuit. Specifically, the outer heat exchanger and the water heat exchanger are connected in such a way that each operates whether the one is operating or not. Therefore, according to the air conditioner of the present invention, the resistance applied to the refrigerant and the flow pressure loss of the refrigerant can be reduced. Moreover, the heat of the engine cooling water is not discharged into the atmosphere in the water heat exchanger; therefore, the engine waste heat can be utilized efficiently to heat the refrigerant.
In the air conditioner, it is preferable to further comprise an adjusting device for adjusting the amount of the refrigerant supplied into the outer heat exchanger and the water heat exchanger, in response to the temperature of the outside air.
According to the air conditioner, when the temperature of the outside air is low, for example, when it is less than 2° C., the operation of the outer heat exchanger is stopped by supplying no refrigerant into the outer heat exchanger, and thereby only the water heat exchanger is operated. The water heat exchanger utilizes the engine waste heat, and it can heat the refrigerant. Therefore, even when the temperature of the outside air is low, the refrigerant can be heated sufficiently, and a heating operation can be carried out without being affected by the temperature of the outside air. Furthermore, when the outer heat exchanger and the water heat exchanger using the engine cooling water at high temperature are operated together, the load applied to the outer heat exchanger can be reduced. Thereby, the electric power required for the fan for introducing the outside air can also be reduced; therefore, noise due to the fan can also be decreased.
In the air conditioner, it is preferable that the outer heat exchanger comprises a refrigerant pipe for falling and discharging a liquid refrigerant condensed therein, the outer heat exchanger is positioned separately from the radiator, and the refrigerant circuit further comprises a liquid refrigerant recovery pipe for flowing the liquid refrigerant discharged from the refrigerant pipe into the refrigerant circuit in which the refrigerant is flowing.
In particular, it is more preferable that the outer heat exchanger is positioned at upstream side with respect to the radiator in the flow direction of the outside air.
Moreover, it is more preferable that the refrigerant pipe is provided in the outer heat exchanger so that upstream portions are always lower than downstream portions in the flow direction of the refrigerant in the heating operation.
It is also more preferable that the refrigerant pipe provided in the outer heat exchanger comprises no sink portion.
Furthermore, it is the most preferable that the refrigerant pipe provided in the outer heat exchanger comprises a plurality of straight tube portions and a plurality of U-shaped tube portions; the straight tube portion extends so that upstream portions are always lower than downstream portions in the flow direction of the refrigerant in the heating operation; and the U-shaped tube portion is arranged between the straight tube portions so that upstream portions are always lower than downstream portions in the flow direction of the refrigerant in the heating operation.
According to the air conditioner, the radiated heat from the radiator does not reach to the outer heat exchanger. Due to this, a decrease of the cooling capability of the air conditioner can be prevented. In addition, according to the air conditioner, when the temperature of the outside air is low, the outer heat exchanger is not operated, and only the water heat exchanger is operated, the liquid refrigerant condensed in the outer heat exchanger can be fallen and discharged from the outer heat exchanger. The discharged liquid refrigerant flows through the refrigerant recovery pipe and reaches to the
Kasahara Hideaki
Ohseki Shigeki
Ohtsuka Takaaki
Yoshimura Atsushi
Ali Mohammad M
Mitsubishi Heavy Industries Ltd.
Oblon, Spivak, McClellend, Maier & Neustadt, P.C.
Tapoicai William E.
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