JPH0233099Y2 - - Google Patents

Description

[Detailed explanation of the idea] (b) Industrial application fields The present invention relates to improvements in refrigeration equipment.

(B) Prior art A conventional example will be explained based on FIG. 1. 1 is a main compressor, 2 is a condenser, 3 is a subcooler for subcooling the condensed refrigerant, 4 is an expansion valve, and 5 is an evaporator. These are sequentially connected via piping to form the main refrigeration circuit 6. 7 is an auxiliary refrigeration circuit connected to the subcooler 3 of the main refrigeration circuit 6, and this auxiliary refrigeration circuit connects an auxiliary compressor 8, a condenser 9, and an expansion valve 10 to the piping of the main refrigeration circuit 6 of the subcooler 3. It is configured by connecting sequentially.

In the refrigeration system with this structure, when the auxiliary refrigeration circuit 7 that supercools the condensed refrigerant in the main refrigeration circuit 6 is operated at approximately the same time as the main refrigeration circuit, the refrigerant accumulated in the subcooler 3 expands in the main refrigeration circuit 6. The pressure is reduced by the valve 4, vaporized by the evaporator 5, and returned to the main compressor 1, and then directly returned to the auxiliary compressor 8 in the auxiliary refrigeration circuit 7. Therefore, although there is little possibility that the liquid refrigerant will return to the main compressor 1, if the outside air temperature is low, the possibility that the liquid refrigerant will return to the auxiliary compressor 8 increases.

(c) Purpose of the invention In view of the above points, the present invention consists of an auxiliary refrigeration circuit in which the auxiliary refrigeration circuit that subcools the condensed refrigerant in the main refrigeration circuit enters operation later than the operation of the main refrigeration circuit. The purpose is to prevent liquid compression in the auxiliary compressor.

(d) Structure of the invention The invention provides a refrigeration system equipped with a main refrigeration circuit consisting of a main compressor, an expansion valve, an evaporator, etc., and an auxiliary refrigeration circuit that cools high-pressure refrigerant in the main refrigeration circuit. An auxiliary compressor, which has a subcooler provided with independent piping in each circuit, and compresses refrigerant in the auxiliary refrigeration circuit and returns the refrigerant to the subcooler on the auxiliary refrigeration circuit side, and a main compressor. A delay timer is provided to operate the auxiliary compressor of the auxiliary refrigeration circuit with a delay of a certain period of time.

The refrigeration system of the present invention with this configuration heats the refrigerant in the cooling section of the auxiliary refrigeration circuit that cools the main refrigeration circuit in the main refrigeration circuit, and then operates the auxiliary refrigeration circuit to supply liquid to the compressor of the auxiliary refrigeration circuit. This prevents the refrigerant from returning.

(E) Embodiments The present invention will be explained below based on embodiments shown in FIGS. 2 and 3.

The same or equivalent parts as in the conventional example shown in FIG. 1 will be described with the same reference numerals. 1 is a main compressor, 2 is a condenser, 3 is a subcooler for subcooling the condensed refrigerant, 4 is an expansion valve, and 5 is an evaporator, which are connected in sequence through piping to form a main refrigeration circuit 6. 7 is an auxiliary refrigeration circuit connected to the subcooler 3 of the main refrigeration circuit 6, and this auxiliary refrigeration circuit connects an auxiliary compressor 8, a condenser 9, and an expansion valve 10 to the piping of the main refrigeration circuit 6 of the subcooler 3. It is configured by connecting sequentially. Reference numeral 11 denotes a delay timer that starts the auxiliary compressor 8 of the auxiliary refrigeration circuit 7 with a certain time delay after the main compressor 1 of the main refrigeration circuit 6 starts.

Next, to explain the operating circuit of FIG. 3, 12 is a power source, and a main compressor motor 14, an auxiliary compressor motor 15, and a delay timer 11 are connected in parallel to this power source via an operation switch 13. . 1
6 is a normally open contact of a delay timer 11 connected in series to the auxiliary compressor motor 15.

In the refrigeration system configured as described above, in the main refrigeration circuit 6, the high-temperature, high-pressure gas refrigerant discharged from the main compressor 1 releases heat when passing through the condenser 2, condenses and liquefies, becomes a low-temperature liquid refrigerant, and is sent to the subcooler. 3, radiates heat to the auxiliary refrigeration circuit 7 side, becomes a lower temperature liquid refrigerant, and enters the expansion valve 4. Further, when the refrigerant whose pressure is reduced here passes through the evaporator 5, it absorbs heat from the surroundings, evaporates, and returns to the main compressor 1. At the same time, in the auxiliary refrigeration circuit 7, the high-temperature, high-pressure gas refrigerant discharged from the auxiliary compressor 8 releases heat as it passes through the condenser 9, condenses and liquefies, and enters the expansion valve 10 as a liquid refrigerant. Also, the refrigerant whose pressure is reduced here enters the subcooler 3, absorbs heat from the liquid refrigerant in the main refrigerant circuit 6, evaporates, and returns to the auxiliary compressor 8, as described above.

The auxiliary refrigeration circuit 7, which performs the above-mentioned functions, is operated with a fixed time delay from the operation of the main refrigeration circuit 6 by the delay timer 11, so that the refrigerant in the auxiliary refrigeration circuit 7 in the subcooler 3 is transferred to the main refrigeration circuit 6. The refrigerant is reliably vaporized by heat radiation from the liquid refrigerant, and this vaporized refrigerant is returned to the auxiliary compressor 8 after operation.

Further, even if the main refrigeration circuit 6 is stopped immediately after the operation of the auxiliary refrigeration circuit 7, the delay timer 11 operates the main refrigeration circuit 6 for a set time, and when the main compressor 1 starts up, the delay timer 11 operates the main refrigeration circuit 6 for a set time. This allows time for a large amount of oil discharged from the compressor to the main refrigeration circuit 6 together with the discharged refrigerant to circulate through the main refrigeration circuit 6 and return to the main compressor 1. A large amount of oil discharged into the main refrigeration circuit 6 at the initial stage of startup can be recovered into the main compressor 1.

(f) Effects of the invention As described above, the present invention is applicable to a refrigeration system equipped with a main refrigeration circuit consisting of a main compressor, an expansion valve, an evaporator, etc., and an auxiliary refrigeration circuit that cools high-pressure refrigerant in this main refrigeration circuit. , an auxiliary compressor having a subcooler provided with independent piping in each of the refrigeration circuits, compressing refrigerant in the auxiliary refrigeration circuit and returning the refrigerant to the subcooler on the auxiliary refrigeration circuit side; Since a delay timer is provided to operate the auxiliary compressor of the auxiliary refrigeration circuit with a fixed time delay from the main compressor, the delay timer operates the auxiliary compressor with a fixed time delay from the main compressor. Then, the refrigerant in the cooling section of the auxiliary refrigeration circuit is preheated and vaporized by the high-pressure refrigerant in the main refrigeration circuit, preventing the liquid refrigerant from returning to the activated auxiliary compressor, and causing the auxiliary compressor to compress the liquid. This can prevent damage. Moreover, even if the main compressor of the main refrigeration circuit is stopped immediately after the operation of the auxiliary compressor that subcools the high-pressure refrigerant discharged from this compressor, the delay timer continues to operate for a certain period of time, so that the The oil discharged from the main refrigeration circuit is returned to the main compressor along with the refrigerant to prevent the engine from running out of oil when restarted.

[Brief explanation of drawings]

FIG. 1 is a conventional refrigeration circuit diagram, FIG. 2 is a refrigeration circuit diagram showing an embodiment of the present invention, and FIG. 3 is an operating circuit diagram. 1... Main compressor, 2... Condenser, 4... Expansion valve, 5... Evaporator, 6... Main refrigeration circuit, 7... Auxiliary refrigeration circuit, 8... Auxiliary compressor, 11... Delay timer.

Claims (1)

[Scope of utility model registration request] In a refrigeration system equipped with a main refrigeration circuit consisting of a main compressor, an expansion valve, an evaporator, etc., and an auxiliary refrigeration circuit that cools high-pressure refrigerant in the main refrigeration circuit, each refrigeration circuit is provided with independent piping. The auxiliary refrigeration circuit has an auxiliary compressor that compresses the refrigerant in the auxiliary refrigeration circuit and returns the refrigerant to the subcooler on the auxiliary refrigeration circuit side, and an auxiliary refrigeration circuit that compresses the refrigerant in the auxiliary refrigeration circuit and returns the refrigerant to the subcooler on the auxiliary refrigeration circuit side, and A refrigeration system characterized by being provided with a delay timer for operating an auxiliary compressor in a circuit.