Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Refrigeration System

a technology of refrigerating system and air conditioner, which is applied in the direction of defrosting, domestic cooling apparatus, application, etc., can solve the problems of air adhesion and moisture, and achieve the effect of effective defrosting, and reducing the time taken to defros

Inactive Publication Date: 2009-02-05
DAIKIN IND LTD
View PDF4 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0039]According to the present invention, during the defrosting operation, frost adhering to the surface of the utilization side heat exchanger (83, 93) is heated from the inside of the utilization side heat exchanger (83, 93) by feeding the refrigerant discharged by the high stage compressor (41, 42, 43) into the utilization side heat exchanger (83, 93). Therefore, the utilization side heat exchanger (83, 93) can be effectively defrosted, which reduces the time taken to defrost it.
[0040]Furthermore, according to the present invention, since during the defrosting operation the heat-source side heat exchanger (44) serves as an evaporator, heat given from air to refrigerant can be used to defrost the utilization side heat exchanger (83, 93). In other words, according the present invention, heat given to refrigerant by the high stage compressor (41, 42, 43) and heat given to refrigerant by the heat-source side heat exchanger (44) are both used to defrost the utilization side heat exchanger (83, 93). This reduces the defrosting time and in turn reduces the power consumption of the refrigeration system during the defrosting operation.
[0041]Particularly, since in the second aspect of the invention the defrosting operation is carried out with the low stage compressor (101, 102, 121, 122) off, this reduces the operating power during the defrosting operation.
[0042]Furthermore, according to the third aspect of the invention, by opening and closing the shut-off valve (SV-2, SV-4) of the bypass pipe (119, 139), the refrigeration system can easily switch between the cooling operation of compressing refrigerant evaporated by the utilization side heat exchanger (83, 93) in two stages, i.e., in the low stage compressor (101, 102, 121, 122) and the high stage compressor (41, 42, 43), and the defrosting operation of allowing refrigerant discharged from the high stage compressor (41, 42, 43) to bypass the low stage compressor (101, 102, 121, 22) and sending the refrigerant to the utilization side heat exchanger (83, 93).
[0043]Furthermore, in the fourth aspect of the invention, during the cooling operation, refrigerant condensed in the heat-source side heat exchanger (44) is allowed to flow through the drain pan heating pipes (81, 91) before being reduced in pressure by the utilization side expansion valve (82, 92). Therefore, according to this aspect of the invention, heat of condensation of refrigerant can be used to melt frost and ice blocks in the drain pan (85, 95) and the water thus obtained can be promptly drained as drainage away from the drain pan (85, 95). Furthermore, the refrigerant flowing through the drain pan heating pipe (81, 91) gives heat to frost and ice blocks in the drain pan (85, 95) and thereby gradually increases its degree of supercooling. Therefore, the enthalpy of refrigerant flowing into the utilization side heat exchanger (83, 93) can be reduced, which increases the air cooling effect of the utilization side heat exchanger (83, 93).
[0044]Furthermore, in the fifth aspect of the invention, during the defrosting operation, the refrigerant used to defrost the utilization side heat exchanger (83, 93) is sent, without reducing its pressure with the utilization side expansion valve (82, 92), to the drain pan heating pipe (81, 91). Therefore, according to this aspect of the invention, also during the defrosting operation, heat of refrigerant flowing through the drain pan heating pipe (81, 91) can be used to melt frost and ice blocks in the drain pan (85, 95).

Problems solved by technology

This causes a problem that moisture in the air adheres to the cooling heat exchanger and freezes on it and the frost on it prevents the cooling of the internal air in the freezer.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Refrigeration System
  • Refrigeration System
  • Refrigeration System

Examples

Experimental program
Comparison scheme
Effect test

embodiment 1

Effects of Embodiment 1

[0142]According to Embodiment 1, during the defrosting operation, frost adhering to the surfaces of the cooling heat exchangers (83, 93) are heated from the insides of the cooling heat exchangers (83, 93) by feeding the refrigerant discharged by the high stage compressors (41, 42, 43) into the utilization side heat exchangers (83, 93). Therefore, the cooling heat exchangers (83, 93) can be effectively defrosted, which reduces the time taken to defrost them.

[0143]Furthermore, according to Embodiment 1, since during the defrosting operation the outdoor heat exchanger (44) serves as an evaporator, heat given from air to refrigerant is used to defrost the utilization side heat exchangers (83, 93). In other words, according to Embodiment 1, heat given to refrigerant by the high stage compressors (41, 42, 43) and heat given to refrigerant by the outdoor heat exchanger (44) are both used to defrost the cooling heat exchangers (83, 93). This reduces the time required ...

embodiment 2

Effects of Embodiment 2

[0163]According to Embodiment 2, like Embodiment 1, during the defrosting operation, frost adhering to the surfaces of the cooling heat exchangers (83, 93) are heated from the insides of the cooling heat exchangers (83, 93) by feeding the refrigerant discharged by the high stage compressors (41, 42, 43) into the cooling heat exchangers (83, 93). Therefore, the cooling heat exchangers (83, 93) can be effectively defrosted, which reduces the time taken to defrost them.

[0164]Furthermore, in Embodiment 2, the refrigeration system (10) can selectively perform the first defrosting operation and the second defrosting operation. According to Embodiment 2, when during the first defrosting operation the refrigeration system (10) is lacking in the capacity to defrost the cooling heat exchangers (83, 93), the low stage compressors (101, 102, 121, 122) are also driven. Therefore, according to Embodiment 2, the amount of heat given to refrigerant can be increased by the sec...

embodiment 3

Modifications of Embodiment 3

[0214]The oil separators (143, 144) and the oil return pipes (141, 142) described in Embodiment 3 may be applied to the refrigeration systems (10) of Embodiments 1 and 2 so that the refrigeration systems (10) can perform a similar cooling operation, a similar defrosting operation and a similar refrigerant recovery action to those in Embodiment 3. Furthermore, for example, in the booster circuits (100, 120) in Embodiment 3 shown in FIG. 9, the bypass pipes (119, 139) may be connected at their one ends to the discharge connection pipes (116b, 136b), respectively, and connected at the other ends to the low stage suction pipes (113, 133), respectively. According to this configuration, during the defrosting operation, the cooling heat exchangers (83, 93) can be defrosted, without sending high-pressure refrigerant into the oil separators (143, 144), by directly introducing it into the bypass pipes (119, 139).

[0215]Furthermore, for example, as shown in FIG. 11,...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A refrigerant circuit (20) includes a low stage compressor (101, 102, 121, 122), a high stage compressor (41, 42, 43), an outdoor heat exchanger (44) and a utilization side heat exchanger (83, 93). During a defrosting operation of the refrigeration system (10), the high stage compressor (41, 42, 43) is driven. Refrigerant discharged from the high stage compressor (41, 42, 43) is pumped into the utilization side heat exchanger (83, 93) to heat frost on it from its inside. Thereafter, the refrigerant evaporates in the outdoor heat exchanger (44), is then compressed by the high stage compressor (41, 42, 43) and is sent again to the utilization side heat exchanger (83, 93).

Description

TECHNICAL FIELD[0001]This invention relates to refrigeration systems operating in a two-stage compression refrigeration cycle and particularly relates to techniques for defrosting a utilization side heat exchanger for cooling the internal air in a freezer or the like.BACKGROUND ART[0002]Refrigeration systems are conventionally known that include a refrigerant circuit operating in a refrigeration cycle and they are widely used as cooling machines for chillers or freezers for storing food and other materials.[0003]For example, Patent Document 1 discloses a refrigeration system for cooling the internal air of a freezer such as in a convenience store. Connected in the refrigerant circuit of this refrigeration system are a low stage compressor, a high stage compressor, an outdoor heat exchanger (heat-source side heat exchanger) and a cooling heat exchanger (utilization side heat exchanger). This refrigeration system operates in a so-called two-stage compression refrigeration cycle in whi...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): F25D21/06F25B1/10F25B41/00F25D21/14F25B43/02
CPCF25B1/10F25B13/00F25B47/025F25B2313/006F25B2400/22F25B2313/02741F25B2400/0401F25B2400/075F25B2400/13F25B2313/0233F25B31/00
Inventor UENO, TAKEOTAKEGAMI, MASAAKIKITA, KOICHITANIMOTO, KENJIODA, YOSHINARINOMURA, KAZUYOSHIKONDO, AZUMA
Owner DAIKIN IND LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products