Air Conditioning Apparatus

• US 20070204635A1
• Filed: 02/24/2005
• Published: 09/06/2007
• Est. Priority Date: 02/24/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Yamashita, Kouji, Tanaka, Kousuke, Tomita, Masahumi, Shida, Yasunori
• Granted Patent: US 7,987,679 B2
• Time in Patent Office: Days
• US Class Current: 62/129
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2309/061 with cycle highest pressure above the supercritical pressure
• CPC Class Codes: F25B 2313/02741 using one four-way valve
• CPC Class Codes: F25B 2313/0293 related to the indoor fan, e.g. controlling speed
• CPC Class Codes: F25B 2313/0294 related to the outdoor fan, e.g. controlling speed
• CPC Class Codes: F25B 2313/0314 Temperature sensors near the indoor heat exchanger
• CPC Class Codes: F25B 2313/0315 Temperature sensors near the outdoor heat exchanger
• CPC Class Codes: F25B 2500/19 Calculation of parameters
• CPC Class Codes: F25B 2500/222 Detecting refrigerant leaks
• CPC Class Codes: F25B 2600/2513 Expansion valves
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25B 9/008 the refrigerant being carbon dioxide

Abstract

By studying or storing refrigerating cycle characteristics of an air conditioning apparatus at the normal time and comparing them with refrigerating cycle characteristics acquired from the air conditioning apparatus at the time of operation, it becomes possible to exactly and accurately diagnose normality or abnormality of the air conditioning apparatus under any installation conditions and environmental conditions, which eliminates operations of inputting a difference between apparatus model names, a piping length, a height difference, etc at the time of apparatus installation. Accordingly, it aims at shortening the time of judging normality or abnormality, and improving the operability. It is characterized by calculating and comparing a measured value (a value of liquid phase temperature efficiency ε_L(SC/dT_c) calculated from temperature information) concerning an amount of a liquid phase part of the refrigerant in the high-pressure-side heat exchanger with a theoretical value (a value of liquid phase temperature efficiency ε_L(1−EXP(−NTU_R)) calculated from the transfer unit number NTU_R at refrigerant side).

Claims

1. An air conditioning apparatus comprising:

a refrigerating cycle to connect a compressor, a high-pressure-side heat exchanger, a throttle device and a low-pressure-side heat exchanger by piping, to circulate a refrigerant of high temperature and high pressure in the high-pressure-side heat exchanger, and to circulate a refrigerant of low temperature and low pressure in the low-pressure-side heat exchanger;

a fluid sending part to make a fluid circulate outside of the high-pressure-side heat exchanger in order to perform a heat exchange between the refrigerant in the high-pressure-side heat exchanger and the fluid;

a temperature detection part of high-pressure refrigerant to detect a temperature in condensing or in middle of cooling of the refrigerant in the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger entrance-side refrigerant to detect a temperature of the refrigerant at an entrance side of the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger exit-side refrigerant to detect a temperature of the refrigerant at an exit side of the high-pressure-side heat exchanger;

a fluid temperature detection part to detect a temperature at a location of the fluid circulating outside of the high-pressure-side heat exchanger;

a temperature detection part of low-pressure refrigerant to detect a temperature in evaporating or in middle of cooling of the refrigerant in the low-pressure-side heat exchanger;

a control part to control the refrigerating cycle, based on each detection value detected by each temperature detection part; and

a calculation comparison part to calculate and compare a measured value and a theoretical value concerning an amount of a liquid phase part of the refrigerant in the high-pressure-side heat exchanger calculated based on the each detection value detected by the each temperature detection part.

3. The air conditioning apparatus of claim 1 wherein, when performing a diagnostic operation of the air conditioning apparatus, the control part controls a rotation number of the fluid sending part to make a temperature difference between the temperature of the refrigerant detected by the temperature detection part of high-pressure refrigerant and the temperature of the fluid detected by the fluid temperature detection part be close to a predetermined value.

4. The air conditioning apparatus of claim 1 wherein, when performing a diagnostic operation of the air conditioning apparatus, the control part controls a frequency of the compressor to make a temperature difference between the temperature of the refrigerant detected by the temperature detection part of high-pressure refrigerant and the temperature of the fluid detected by the fluid temperature detection part be close to a predetermined value.

5. The air conditioning apparatus of claim 1 wherein, when performing a diagnostic operation of the air conditioning apparatus, the control part controls a degree of opening of the throttle device to make the temperature of the refrigerant detected by the temperature detection part of low-pressure refrigerant be close to a predetermined value.

7. The air conditioning apparatus of claim 1, further comprising a judgment part to compare measured values concerning the amount of the liquid phase part of the refrigerant in the high-pressure-side heat exchanger calculated in past and at present, and to judge a refrigerant leak, based on a change of the measured values.

8. The air conditioning apparatus of claim 1, further comprising a judgment part to compare measured values concerning the amount of the liquid phase part of the refrigerant in the high-pressure-side heat exchanger calculated in past and at present, and to judge a blockage in the refrigerating cycle or abnormality of an opening degree of the throttle device, based on a change of the measured values.

15. The air conditioning apparatus of claim 1, wherein a refrigerant of CO₂ is used.

2. An air conditioning apparatus comprising:

a refrigerating cycle to connect a compressor, a high-pressure-side heat exchanger, a throttle device and a low-pressure-side heat exchanger by piping, to circulate a refrigerant of high temperature and high pressure in the high-pressure-side heat exchanger, and to circulate a refrigerant of low temperature and low pressure in the low-pressure-side heat exchanger;

a fluid sending part to make a fluid circulate outside of the high-pressure-side heat exchanger in order to perform a heat exchange between the refrigerant in the high-pressure-side heat exchanger and the fluid;

a temperature detection part of high-pressure refrigerant to detect a temperature in condensing or in middle of cooling of the refrigerant in the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger entrance-side refrigerant to detect a temperature of the refrigerant at an entrance side of the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger exit-side refrigerant to detect a temperature of the refrigerant at an exit side of the high-pressure-side heat exchanger;

a fluid temperature detection part to detect a temperature at a location of the fluid circulating outside of the high-pressure-side heat exchanger;

a temperature detection part of low-pressure refrigerant to detect a temperature in evaporating or in middle of cooling of the refrigerant in the low-pressure-side heat exchanger;

a temperature detection part of low-pressure-side heat exchanger exit-side refrigerant to detect a temperature of the refrigerant at an exit side of the low-pressure-side heat exchanger;

a control part to control the refrigerating cycle, based on each detection value detected by each temperature detection part; and

a calculation comparison part to calculate a measured value and a theoretical value concerning an amount of a liquid phase part of the refrigerant in the high-pressure-side heat exchanger obtained based on the each detection value detected by the each temperature detection part.

6. The air conditioning apparatus of claim 2 wherein, when performing a diagnostic operation of the air conditioning apparatus, the control part calculates a degree of superheat of the low-pressure-side heat exchanger, based on temperatures of the refrigerant detected by a temperature detection part of low-pressure-side gas pipe for detecting a temperature at the exit of the low-pressure-side heat exchanger and by the temperature detection part of low-pressure refrigerant, and controls a degree of opening of the throttle device so that the degree of superheat can be close to a predetermined value.

9. An air conditioning apparatus comprising:

a refrigerating cycle to connect a compressor, a high-pressure-side heat exchanger, a throttle device and a low-pressure-side heat exchanger by piping, to circulate a refrigerant of high temperature and high pressure in the high-pressure-side heat exchanger, and to circulate a refrigerant of low temperature and low pressure in the low-pressure-side heat exchanger;

a fluid sending part to make a fluid circulate outside of the high-pressure-side heat exchanger in order to perform a heat exchange between the refrigerant in the high-pressure-side heat exchanger and the fluid;

a temperature detection part of high-pressure refrigerant to detect a temperature in condensing or in middle of cooling of the refrigerant in the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger entrance-side refrigerant to detect a temperature of the refrigerant at an entrance side of the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger exit-side refrigerant to detect a temperature of the refrigerant at an exit side of the high-pressure-side heat exchanger;

a fluid temperature detection part to detect a temperature at a location of the fluid circulating outside of the high-pressure-side heat exchanger;

a temperature detection part of low-pressure refrigerant to detect a temperature in evaporating or in middle of cooling of the refrigerant in the low-pressure-side heat exchanger; and

a control part to control the refrigerating cycle, based on each detection value detected by each temperature detection part,

wherein the throttle device includes an upstream side throttle device, a receiver, and a downstream side throttle device, and the control part performs a special operation mode that the control part moves a surplus refrigerant in the receiver into the high-pressure-side heat exchanger by making the refrigerant at an exit of the receiver be a two-phase state by way of making an opening area of the upstream side throttle device be smaller than an opening area of the downstream side throttle device.

11. The air conditioning apparatus of claim 9, wherein the air conditioning apparatus includes a timer inside and the control part has a function of going to the special operation mode every specific time period by the timer.

13. The air conditioning apparatus of claim 9, wherein the control part has a function of going to the special operation mode by an operation signal from outside by wired or wireless.

10. An air conditioning apparatus comprising:

a refrigerating cycle to connect a compressor, a high-pressure-side heat exchanger, a throttle device and a low-pressure-side heat exchanger by piping, to circulate a refrigerant of high temperature and high pressure in the high-pressure-side heat exchanger, and to circulate a refrigerant of low temperature and low pressure in the low-pressure-side heat exchanger;

a fluid sending part to make a fluid circulate outside of the high-pressure-side heat exchanger in order to perform a heat exchange between the refrigerant in the high-pressure-side heat exchanger and the fluid;

a temperature detection part of high-pressure refrigerant to detect a temperature in condensing or in middle of cooling of the refrigerant in the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger entrance-side refrigerant to detect a temperature of the refrigerant at an entrance side of the high-pressure-side heat exchanger;

a temperature detection part of high-pressure-side heat exchanger exit-side refrigerant to detect a temperature of the refrigerant at an exit side of the high-pressure-side heat exchanger;

a fluid temperature detection part to detect a temperature at a location of the fluid circulating outside of the high-pressure-side heat exchanger;

a temperature detection part of low-pressure refrigerant to detect a temperature in evaporating or in middle of cooling of the refrigerant in the low-pressure-side heat exchanger;

a control part to control the refrigerating cycle, based on each detection value detected by each temperature detection part; and

an accumulator provided between the low-pressure-side heat exchanger and the compressor,

wherein the control part performs a special operation mode that the control part moves a surplus refrigerant in the accumulator into the high-pressure-side heat exchanger by making the refrigerant flowing into the accumulator be a gas refrigerant by way of controlling the throttle device.

12. The air conditioning apparatus of claim 10, wherein the air conditioning apparatus includes a timer inside and the control part has a function of going to the special operation mode every specific time period by the timer.

14. The air conditioning apparatus of claim 10, wherein the control part has a function of going to the special operation mode by an operation signal from outside by wired or wireless.