High Efficiency Inverter Scroll Compressors Yasuhiro MURAKAMI, Hiroshi KITAURA, Kazuhiko MATSUKAWA,Katsumi KATOU, Yoshitomo TSUKA, Yasuo MIZUSHIMA July 11-14, 2016
Overview 1. The structure of the traditional compressor 2. Office building load rates and operation times 3. Back Pressure Control and an Injection Mechanism with a Check Valve to improve overall compressor efficiency 4. Efficiency improvement results 2
Overview 1. The structure of the traditional compressor 2. Office building load rates and operation times 3. Back Pressure Control and an Injection Mechanism with a Check Valve to improve overall compressor efficiency 4. Efficiency improvement results 3
Overview 1. The structure of the traditional compressor 2. Office building load rates and operation times 3. Back Pressure Control and an Injection Mechanism with a Check Valve to improve overall compressor efficiency 4. Efficiency improvement results 4
Overview 1. The structure of the traditional compressor 2. Office building load rates and operation times 3. Back Pressure Control and an Injection Mechanism with a Check Valve to improve overall compressor efficiency 4. Efficiency improvement results 5
Overview 1. The structure of the traditional compressor 2. Office building load rates and operation times 3. Back Pressure Control and an Injection Mechanism with a Check Valve to improve overall compressor efficiency 4. Efficiency improvement results 6
1. STRUCTURE OF COMPRESSOR High thrust mechanism Low pressure High pressure Figure 1: Traditional technology 7
Outdoor Unit Operation Time [hr] 2. OFFICE BUILDING LOAD RATES AND OPERATION TIMES Load rate Figure 2: Load Rate / Operation Time 8
3. HIGH EFFICIENCY TECHNOLOGY New technology: Injection mechanism with a check valve New technology: Back pressure control Figure 3: New technologies 9
3. HIGH EFFICIENCY TECHNOLOGY 3.1 Back Pressure Control Traditional Model Low Pressure Fixed scroll Orbiting scroll High Pressure Newly Developed Model Fixed scroll Orbiting scroll Low Pressure Arbitrary Pressure High Pressure Figure 4: The structure of back pressure control 10
Compressor input power ratio 3. HIGH EFFICIENCY TECHNOLOGY 3.1 Back Pressure Control After changing the value of arbitrary pressure, test results show that the compressor input at each condition becomes smaller when the ratio of middle pressure to suction pressure is between 1.4 and 1.6. Cooling high load condition Cooling low load condition Heating high load condition Heating low load condition Arbitrary pressure / Suction pressure Figure 5: Relation between arbitrary pressure and compressor input ratio 11
3. HIGH EFFICIENCY TECHNOLOGY 3.2 Injection mechanism with check valve Middle pressure injection structure Check valve Dead volume of traditional injection structure Compression chamber Dead volume of injection structure with check valve Figure 6: The structure of injection mechanism with check valve 12
Indicated efficiency ratio 3. HIGH EFFICIENCY TECHNOLOGY 3.2 Injection mechanism with check valve The dead volume drops to less than 1/20 by employing the new structure with the check valve set nearby the compression chamber. Traditional Model (Without check valve) Newly Developed Model (With check valve) Dead volume / Suction volume Figure 7: The Relation between dead volume and indicated efficiency 13
Compressor efficiency ratio 3. HIGH EFFICIENCY TECHNOLOGY 3.2 Injection mechanism with check valve Where the compressing ratio is 1.8 without gas injection, the efficiency was improved 2.2pt by employing the injection structure with a check valve. +2.2pt Without check valve With check valve Figure 8: Efficiency ratio comparison: employing injection without valve vs with valve 14
Compressor efficiency ratio 3. HIGH EFFICIENCY TECHNOLOGY 3.3 Efficiency Improvement Results Efficiency of inverter scroll compressor employing back pressure control and middle pressure injection with a check valve. Newly Developed Model Effect of back pressure control and injection check valve Traditional Model Effect of injection Load rate Figure 9: Efficiency of back pressure control and injection with a check valve 15
Summary 1. Efficiency was dramatically improved by controlling the back pressure of the arbitrary pressure as the input becomes optimum at each condition. 2. By employing the injection structure with a check valve, the efficiency was improved at high load operation condition by injection; and the efficiency drop down was suppressed at small load operation condition. 3. The efficiency of the whole operation area was improved by using a back pressure control structure and injection mechanism with a check valve. 16
Summary 1. Efficiency was dramatically improved by controlling the back pressure of the arbitrary pressure as the input becomes optimum at each condition. 2. By employing the injection structure with a check valve, the efficiency was improved at high load operation condition by injection; and the efficiency drop down was suppressed at small load operation condition. 3. The efficiency of the whole operation area was improved by using a back pressure control structure and injection mechanism with a check valve. 17
Summary 1. Efficiency was dramatically improved by controlling the back pressure of the arbitrary pressure as the input becomes optimum at each condition. 2. By employing the injection structure with a check valve, the efficiency was improved at high load operation condition by injection; and the efficiency drop down was suppressed at small load operation condition. 3. The efficiency of the whole operation area was improved by using a back pressure control structure and injection mechanism with a check valve. 18
Summary 1. Efficiency was dramatically improved by controlling the back pressure of the arbitrary pressure as the input becomes optimum at each condition. 2. By employing the injection structure with a check valve, the efficiency was improved at high load operation condition by injection; and the efficiency drop down was suppressed at small load operation condition. 3. The efficiency of the whole operation area was improved by using a back pressure control structure and injection mechanism with a check valve. 19
Conclusion Further energy saving in air conditioning for commercial buildings can be accomplished with the new design techniques I have presented today. 20