Development of compact air heat pump inverter module chiller Air heat pump chiller DT-R(4 units) Takuya ITO Mitsubishi Electric Corporation 1
Biography Belonging The Air-conditioning & Refrigeration systems works Have developed the chiller since 1997 Planning new product & design Takuya ITO Mitsubishi Electric Corporation 2
Procedure of presentation 1. Background Purpose 2. Features of DT-R 3. Energy-saving technology and downsizing technology 4. Simplification of multiple installation construction 5. High efficiency by the multiple module control 6. Conclusions 3
1. Background Purpose (1) Air-cooled heat pump chillers The chillers are usually used as a central heat source machine for outdoor air processing, air condition or process cooling. The chillers have been taken notice of effectiveness to prevent global warming to reduce the refrigerant of the indoor unit. Outdoor unit Air-cooled heat pump chiller Indoor unit Air heat exchanger expansion valve Water heat exchanger Water coil 4 way valve Refrigerant pipe Compressor ACC (Accumulator) Water pipe Pump General air conditioning system(chiller) 4
1. Background Purpose (2) Chiller s market A further improvement of performance was requested for both 100% load and part load conditions from the viewpoint of global warming prevention. A smaller footprint and more capacity is needed. developed the high efficiency, compact new air-cooled heat pump chiller DT-R 5
2. Features of DT-R (1) Y-structure The lack of service space is solved between machine rooms by Y-structure. (2) The highest EER in chiller market(2015/10) The EER(50HP 3.47) is achieved by using high performance device of refrigeration circuit. Part load performance is better than conventional machines due to the mounted inverter compressor. (3) High efficiency due to the multiple module control DT-R is designed for high-efficiency operation that can control a number of units during multiple operations. Y-structure machine room Service space of machine room the side view (2 connected units) Performance DT-R Horsepower 60HP 50HP Cooling Capacity(kW) 180 150 EER 1 3.12 3.47 SEER 4.12 4.44 Heating Capacity(kW) 180 150 COP 3.24 3.42 Dimension 2,350(H) 1,080(W) 3,400(D) Refrigerant R410A Capacity per area(kw/m 2 ) 49.02 40.85 1 Difference of inlet and outlet water temperature is 7 degree celsius 6
3. Energy-saving technology and downsizing technology 7
3. Energy-saving technology and downsizing technology (1) Air heat exchanger 1) The new slit fin of high heat transfer rate The heat transfer rate was improved against our conventional unit by increasing the thermal boundary layer. 2) Large diameter fan The flow rate was increased against our conventional unit. Large diameter fan Air heat exchanger The ring fin of our conventional unit The new slit fin of DT-R (the ZIGZAG slit fin) The new slit fin and large diameter fan 7
3. Energy-saving technology and downsizing technology 3) High efficiency mounting DT-R was shaped for intake from all four sides by mounting the four L-bend air heat exchangers diagonally downsizing of the unit and to reduce space with multiple installation, Air discharge Inlet air from four directions Air Intake Mount diagonally Air discharge Air Intake Air Intake Air Intake (a) External (b) Top view (c) Front view 9
3. Energy-saving technology and downsizing technology (2) dual inverter(high-efficiency scroll compressor and fan motor) 1) inverter compressor The inverter compressor reaches maximum EER when at about 60% capacity. 2) inverter fan motor the flow rate is low the air heat exchanger cannot function sufficiently. the flow rate is high fan motor input is increased DT-R can drive at high efficiency due to rotational speed control for optimum air flow rate in accordance with the operating conditions of the unit. 120% 110% EER ratio 110% 100% 90% 80% 70% 60% Scroll compressor (Inverter capacity control) Screw compressor (Mechanical capacity control) EER ratio 100% 90% 80% Input Increase by high-pressure rise The best air flow rate Fan input increase 50% 20% 30% 40% 50% 60% 70% 80% 90% 100% Cooling capacity ratio Comparison of compressor performance 70% 40% 60% 80% 100% 120% Air flow ratio Performance to change in air flow rate 10
3. Energy-saving technology and downsizing technology (2) dual inverter(high-efficiency scroll compressor and fan motor) <Part load performance(air temp. :35, Water temp. 7 > Optimum control of compressor frequency fan rotational speed according to load EER ratio 125% (at 55% capacity) 130% Air temp. :35 Outlet water temp. :7 EER ratio 120% 110% 100% +25% 90% 40 50 60 70 80 90 100 Cooling capacity ratio(%) Part load performance of DT-R 11
3. Energy-saving technology and downsizing technology (3) Two evaporation temperature cycle 1) Independent refrigeration cycle connected in series on the water side 2) Improvement of EER by raising the evaporation temperature on the upstream side of cold water. Air heat exchanger 4-way valve Circuit 1 Circuit 3 expansion valve Compressor 9.5 7 12 Water heat exchanger Refrigeration cycle of DT-R Upstream Circuit 2 Circuit 4 Downstream Evaporation temp. difference against 1-evap cycle ( ) EER ratio 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 104% 103% 102% 101% 100% 99% 98% 97% 96% +2.2 3 4 5 6 7 8 9 10 Difference of water temperature upon entrance and exit( ) 2% +3.1 3% 2-evap.-cycle 1-evap.-cycle 3 4 5 6 7 8 9 10 Difference of water temperature upon entrance and exit( ) 12
3. Energy-saving technology and downsizing technology (4) Module coupling structure By connecting the module, DT-R achieved a great reduction of installation space. <Air Intake space> Because of the Y-shaped structure, It s easy for air intake even with consolidated installation. Y-shaped structure Side view of 3 connected units 13
3. Energy-saving technology and downsizing technology (4) Module coupling structure <Comparison of installation area with conventional model(300hp)> The installation space was 48% compared with the conventional machine greatly reducing the installation area space requirements.. Installed areas 38.5m 2 (48%) Installed areas 79.9m 2 (100%) 1.08 0.9 3.4 0.9 5.2 0.9 0.9 7.4 (a)development model (60HP 5) (b) Conventional model (100HP 3) Comparison of installation areas 14
4. Simplification of multiple installation construction 15
4. Simplification of multiple installation construction < Selectable water piping specifications> 1.Standard piping can be adopted to and customized for various system. 2.Built-in header establish header pipe connection for each module (collection piping) in the machine room. Piping space can be reduced. Piping space can be reduced Standard piping Built-in header 16
4. Simplification of multiple installation construction It can easily be constructed and shorten the construction period by reducing the connection points and the piping space at the time of multiple installation. Piping space can be reduced Plumbing connection point Built-in header Plumbing at the site The piping inside the module (Install at the factory) Example of built-in header 17
5. High efficiency by the multiple module control 18
5. High efficiency by the module multiple control 1.Control of each module Outlet water temperature constant control Optimum control of the number of compressors and frequency and fan rotation speed so that outlet water temperature is constant 2. multiple module control determines the number of units based on the amount of the compressor frequency of all units. Outlet water 空調負荷 空調負荷 Remote controller 17
5. High efficiency by the multiple module control EER ratio at multiple system(60hpx4) keeping high EER to min-load. Determine the optimal number of module. 130% 1-unit 2-unit 3-unit 4-unit 120% EER ratio 110% 100% Keeping 110%-EER ratio +20% 90% 4-UNIT (No number of control) 80% 0% 20% 40% 60% 80% 100% Cooling capactity ratio Comparison of part-load performance of the multiple numbers of controls 20
5. Conclusions The new type chiller DT-R was developed to improve the energy saving and the installation area of air-cooled heat pump chiller. 1. The top level of EER3.47(50HP) and in chiller market was achieved by high performance devices. 2.DT-R has achieved a 48% smaller footprint than conventional machines by the following technology: a) By the New-Y-Shape structure, the modules can connect unit to unit and the space between the modules can be eliminated. b) By using highly-efficient inverter compressors and adopting highly-efficient small air heat exchangers equipped with Zigzag-slit fins, we were able to achieve both high-efficiency and small installation space. c) By using application of highly-efficient 2-evaporation temperature cycles, we were able to achieve the reduction in the water heat exchanger. 21
5. Conclusions We will continue to push further for high efficiency, compact designs and global environment friendly products. Thank you all very much for your attention. 22