JPS5969661A - Refrigeration cycle - 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] The present invention relates to improving the efficiency of refrigeration cycles.

Conventionally, in a refrigeration cycle, an expansion valve that performs irreversible adiabatic throttling is usually used as a pressure reducing device, but such a system has the problem that the refrigeration effect is insufficient and the compressor driving power is large.

The present invention has been made in view of the above points, and includes a pressure reducing device,
The purpose is to improve the refrigeration effect (1) and save power by constructing an expander that enables reversible adiabatic expansion and using the output of this expander as auxiliary power for driving the compressor.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 illustrates the cycle of the present invention, in which a high stage expander 2 is arranged from a condenser 1 through a pipe 10.
It is also connected to the shaft of the compressor 5, and further connected to the shaft of the compressor 5. The outlet of the expander 2 reaches the gas-liquid separator 3 via a pipe 11, and from this gas-liquid separator 3, a pipe 13 connects a part to the low-stage expander 7 and the other part to the pipe. 12 are connected to the engine boats of the compressor 5, respectively. From the outlet of the low pressure expander 7, it reaches the evaporator 4 via the piping 14,
The evaporator 4 is connected to the inlet of the compressor 5 by a pipe 8.

The shaft of the compressor 5 is connected to the shaft of the expander 2.7 as described above, and its main shaft is connected to a prime mover (for example, a motor) 6 to transmit rotation. The outlet of the compressor 5 is connected to the inlet of the condenser 1 via a pipe 9 to form a closed circuit (2).

In the condenser 1, the refrigerant cooled and liquefied by water or air is in the state of 10' in the Mollier diagram of Fig. 2.
Reversible adiabatic expansion occurs in the high-stage expander 2, and It' in Fig. 2
The gas-liquid separator 3 is reached in this state, and the output generated in this Ill expansion process is transmitted to the compressor 5 via the shaft.

The refrigerant is separated into a saturated liquid 13' corresponding to an intermediate pressure and a saturated gas 12' inside the gas-liquid separator 3, and the degree of dryness at this time is defined as X. The saturated liquid 13' is further passed through the lower stage expander 7.
At this point, the compressor undergoes reversible adiabatic expansion and reaches a state of 14°, and the output at this time is also transmitted to the compressor 5 via the shaft. The refrigerant at 14' reaches the evaporator 4, where it is evaporated and cooled, and in the state at 8' is sucked into the compressor 5 and compressed.
However, as a result of the refrigerant 12' in the gas-liquid separator 3 being injected into the compressor 5, the refrigerants 12' and 15' are mixed in the compressor 5, resulting in the state 16', and undergo compression. As a result, it is compressed to the state of 9 and reaches the capacitor 1. The refrigeration cycle is operated by forming a closed cycle as shown in (3) above, but the compression power of the condenser 5 can be used not only by the prime mover 6, but also by the expansion output of the expanders 2 and 7. This greatly contributes to improving the efficiency of the refrigeration cycle.
The saturation temperature of the high stage, middle stage, and low stage is 50.25.5℃, respectively.
When shown in the Mollier diagram, it becomes as shown in Fig. 2.

This leads to an efficiency improvement of 33%.

In the above example, the compressor 5 is an injection type, but as in conventional two-stage compression, there are two compressors, a low-stage compressor and a high-stage compressor, and the output of the expander 2.7 is transferred to these compressors. It is equally effective as a supplement.

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[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of an embodiment of the present invention, and FIG. 2 is a Mollier diagram used to explain the operation of the present invention. ■...Capacitor, 2...High stage expander, 3...
... Gas-liquid separator, 4... Evaporator, 5... Compressor, 6... Prime mover, 7... Low-stage expander. Representative Patent Attorney Takashi Okabe (5) 326

Claims (1)

[Claims] A refrigeration cycle that uses an expander capable of reversible adiabatic expansion as a pressure reducing device in a two-stage compression and two-stage expansion refrigeration cycle, and connects the output shaft of the expander to the drive shaft of the compressor.