6 VRV AHU Application [PDF]

Zitiervorschau

6/8/2016

Top secret Secret Internal use only Public

VRV to AHU connection Application guide

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01. Basics In this chapter we will learn about: • • •

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How VRV can be useful for AHU air treatment What are the benefits of this application What possibilities do you have

Title - Internal use only

THE BASICS Where to use VRV? Humidification section Treatment section Filter section

Drop separator Post-heating section

Adjustment damper

Fan section View: SECTION

Inlet Air

Supply Air

Here we can apply VRV for cooling or heating the supplied air in DX coils.

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Title - Internal use only

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THE BASICS What do you need to use VRV for cooling and heating the air in the AHU?

4. Control box (controls the expansion valve set and outdoor unit(s) capacity

1. Outdoor unit(s) (work as CCU)

3. Expansion valve set (refrigerant flow and pressure control in DX coil)

EXV control 5. Local or central remote controllers (in some cases) communication

Thermistors

R410A liquid R410A gas

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2a (optional). Air Handling Unit

2. Air Handling Unit with properly

control box (Daikin or 3rd Party)

designed DX coils (Daikin or 3rd Party)

Title - Internal use only

THE BASICS What are the benefits? 1) Immediate Cooling and Heating under any ambient or room conditions → less heat transfer losses, fast and accurate response to load changes → better comfort and less energy consumption compared to water cooling/heating coils coupled with chillers. 2) Better management of load for medium size spaces due to VRV technologies. • Total solution: AHU can work together with other VRV indoor units in same system • Extended operating range • Accurate temperature control due to inverter capacity management • Quick switchover between cooling & heating. → better comfort and wider possibilities compared to water systems and ON/OFF CCUs. 3) Top Energy Efficiency and reliability • Energy saving due to inverter technology • No inrush current • Less start/stop cycles, longer compressors lifetime • VRV IV: VRT control is furthermore increasing seasonal efficiency • VRV IV: numerous settings targeting either higher efficiency or quick response. → lower running costs 4) Continuous Heating with VRV IV dedicated heat pump range: • Avoid Cold drafts during defrost cycle • Fresh air can be continuously supplied at comfortable temperatures → better comfort 6

Title - Internal use only

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THE BASICS What are the configuration possibilities? DX coils + VRV IV outdoor unit

DX coil + ERQ outdoor unit

Supply air temperature control or Return air temperature control

Supply air temperature control or Return air temperature control

Return air temperature control

VRV IV Heat pump

VRV IV Heat recovery

(up to 150 kW on Multi combination)

(up to 150 kW on Multi combination)

(1 outdoor+ 1 DX kit)

•Pair combination

•Multi combination:

•Heat pump

(1 outdoor + 1 DX kit)

ERQ (up to 25 kW) •Pair combination

- AHU+VRV IU

•Multi combination: (1 outdoor+ several DX kits): - AHU+AHU - AHU+VRV IU (only return air control is available in this case) 7

Title - Internal use only

THE BASICS What are the temperature control possibilities? Ts (supply air temperature sensor)

Te (evaporator temperature sensor)

Td (discharge air temperature sensor)

DDC controller (AHU’s own controller, collecting data from sensors and forming capacity demand signal)

Supply Air

Return Air Tr (room air temperature sensor)

X: Control of supply or return air temperature ( uses Td, Ts or Tr- all field supplied sensors) with external controller (DDC) using an un-proportional 0~10 V algorithm for capacity control Y: Control of evaporating/condensing temperature, indirect room temperature control (uses Te- Daikin supplied) with 3rd party thermostat and Daikin controller BRC1D52 or BRC1E52A/B used for field settings and error indication Z: Control of supply or return air temperature (uses Ts or Tr- Daikin or field supplied sensors) with Daikin controller BRC1D52 or BRC1E52A/B used for control, field settings and error indication W: Control of supply or return air temperature (uses Td, Ts or Tr- all field supplied sensors) with external controller (DDC) using a proportional 0~10 V algorithm for capacity control 8

Title - Internal use only

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02. Selection and build-up In this chapter we will learn about: • • •

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How the selection process goes What components do you need in each case What are the restrictions and limitations

Title - Internal use only

LINE-UP (WHAT DO YOU HAVE TO SELECT FROM) 1. Outdoor units The following ranges are suitable: • ERQ (11-28 kW); • VRV IV HP RXYQ-T/RYYQ/T/RYMQ-T(22-150 kW) • VRV IV HR REYQ-T (22-150 kW) • Water Cooled VRV RWEYQ-T (22-84 kW)

3. Air handling units: AHU 3rd Party

Daikin Easy (500-33000 m3/h) Professional (750-144000 m3/h)

2. Control boxes: • EKEQFCBA (for all types of VRV and ERQ) • EKEQDCBA (for ERQ only) • EKEQMCBA (for VRV only)

Integrated Daikin DDC controllers possible

Energy (750-100000 m3/h) Modular (500-25000 m3/h)

4. Expansion valves sets: Model

EKEXV50

EKEXV63

EKEXV80

EKEXV100

EKEXV125

EKEXV140

EKEXV200

EKEXV250

EKEXV400

EKEXV500

Allowed coil capacity, kW (cooling)

5,0-6,2

6,3-7,8

7,9-9,9

10,0-12,3

12,4-15,4

15,5-17,6

17,7-24,6

24,7-30,8

35,4-49,5

49,6-61,6

Allowed coil capacity, kW (heating)

5,6-7,0

7,1-8,8

8,9-11,1

11,2-13,8

13,9-17,3

17,4-19,8

19,9-27,7

27,8-34,7

39,8-55,0

55,1-69,3

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Title - Internal use only

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SELECTION PROCESS Step 1. Calculate the required coil capacity, determine coil parameters and select expansion valves AHU selection software

Air flow On coil air temperature and humidity (summer/wi nter)

Coil capacity (cooling/heating)

Coil parameters Volume # of circuits

Off coil air temperature (summer/wi nter)

# and type of expansion valve sets

At this stage consider limitations (refer to EXV data books): • •

Allowed MIN and MAX cooling capacity for EXV sets Allowed MIN and MAX heating capacity for EXV sets

AHU software suggests 65 kW single circuit coil. Is it OK?

AHU software suggests 6 kW double circuit coil (3+3 kW). Is it OK?

No, max. capacity for single circuit is 61,6 kW. You need to split your coil.

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VRV selection software

No, min. capacity for single circuit is 5 kW. You need to go to 1 circuit coil.

Title - Internal use only

SELECTION PROCESS Step 2. Determine your system configuration and select control box(es) and outdoor units Based on selected EXV capacity (@ step 1), if ≤28 kW

X/Y Control

Z Control X/Y/W Control

Pair

ERQ VRV

System configuration

Based on selected EXV capacity (@ step 1), if > 28 kW

Multi It is important to understand how temperature control modes work to select the most appropriate for your project!

Single AHU with multicircuit coil

X/Y/W Control

X/Y/W Control

EKEQFCB(A)

EKEQDCB(A) EKEQFCB(A) EKEQFCB(A) Select the outdoor unit based on total connected EXV capacity

Several AHUs AHUs and VRV indoor units

Z Control

EKEQMCB

Select the outdoor unit based on total connected EXV capacity

VRV selection software 12

Title - Internal use only

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TEMPERATURE CONTROL MODES X-Control – how it works?

EXV is controlled to provide certain Te (evaporation temperature)

Measurements of: • Tr or • Ts or • Td

0-10 V signal

EKEQF control box

DDC controller V - voltage input to the 10V

Voltage from the DDC controller is linear function of ΔT: 5 V= × ∆T + 5 ∆Tmax Depending on the input voltage, EKEQ control box will send to the outdoor unit the capacity step signal:

control box

5V ΔT

0V ΔT=0

-ΔTmax

+ΔTmax

temperature measured by the sensor; ΔTmax – maximum allowed difference between the set point and the temperature measured by the sensor, 2-50C – is programmed during commissioning.

Cooling

Heating

Level 1

Capacity ↓↓

Capacity ↑↑

Level 2

Capacity ↓

Capacity ↑

Keep current capacity

Level 4

Capacity ↑

Capacity ↓

Level 5

Capacity ↑↑

Capacity ↓↓

Title - Internal use only

TEMPERATURE CONTROL MODES X-Control – how it works (continued)? Measurements of: • Tr or • Ts or • Td

The EKEQ controller switches between capacity levels like this: If the voltage from DDC is increasing:

10V 8,8V 6,8V 3,8V 1,8V 0V

Level 5 Level 4 Level 3 Level 2 Level 1

EXV is controlled to provide certain Te (evaporation temperature)

0-10 V signal

DDC controller

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Capacity level

Level 3

ΔT – is the difference between the set point and the

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Capacity step signal to the outdoor unit: • Level 1 • Level 2 • Level 3 • Level 4 • Level 5

If the voltage from DDC is decreasing:

10V 8,2V 6,2V 3,2V 1,2V 0V

Level 5 Level 4 Level 3 Level 2 Level 1

EKEQF control box

Capacity step signal to the outdoor unit: • Level 1 • Level 2 • Level 3 • Level 4 • Level 5

What are the benefits? When to use this type of control? It is expensive to buy and setup…

The benefits are: • Fast response to load variation (capacity is immediately changed as a function of measured temperature) • Precise temperature control You may use this type of control in comfort sensitive applications. This is also used by default in Daikin AHU controls.

Title - Internal use only

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TEMPERATURE CONTROL MODES Y-Control – how it works?

EKEXV EV box

Te/Tc control

3rd Party Thermostat

EKEQF control box

ON/OFF signal Te/Tc control Settings, incl. Te/Tc

Measures room temperature, sends ON/OFF signal to control box when set point is reached

Outdoor unit

BRC1(D,E) What are the benefits? When to use this type of control? Looks very easy and cheap, what are the drawbacks?

Used to make the necessary settings

How does the system work? •

•

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Evaporation and condensing temperatures (for cooling and heating modes respectively) are fixed, by field settings on remote controller: • Te = 5…120C (default 80C) • Tc = 43…490C (default 460C) The system will only deviate from set Te/Tc in case of safe modes activation

•

Cheap and simple solution (no additional DDC controller required) • No direct temperature control. Room temperature may fluctuate significantly You may use this type of control in comfort insensitive applications with constant cooling/heating load (technical rooms).

Title - Internal use only

TEMPERATURE CONTROL MODES

EXV is controlled to provide certain Te (evaporation temperature)

W-Control – how it works? Measurements of: • Tr or • Ts or • Td

0-10 V signal

EKEQF control box

DDC controller DDC outputs the voltage signal proportional to ΔT (same as X-control) ∆𝑇 𝑉= × 10 ∆𝑇𝑚𝑎𝑥

EKEQ box selects the capacity step and sets it by fixing the Te/Tc at certain level (not direct % of capacity!)

Capacity step signal to the outdoor unit: • Level 1 = 0% capacity • Level 2 = 40% capacity • Level 3 = 60% capacity • Level 4 = 80% capacity • Level 5 = 100% capacity

The system tries to adjust the compressor speed to reach ΔT=0 with this Te/Tc

ΔT measurement

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Capacity level

Voltage from DDC controller

Level 1

0,8

Level 2

2,5

Level 3

5

Level 4 Level 5

Te setting (cooling)

Tc setting (heating)

Approx. % of capacity

-

-

0 (OFF)

13,50C

310C

40

110C

360C

60

7,5

8,50C

410C

80

9,2

60C

460C

100

We can (though indirectly) set the % of system capacity by means of 0-10 V signal. Most of the AHU controllers available in the market are suitable for this without any additional programming.

Title - Internal use only

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TEMPERATURE CONTROL MODES

EXV is controlled to provide certain Te (evaporation temperature)

W-Control – how it works (continued)? Measurements of: • Tr or • Ts or • Td

0-10 V signal

EKEQF control box

DDC controller

Capacity step signal to the outdoor unit: • Level 1 = 0% capacity • Level 2 = 40% capacity • Level 3 = 60% capacity • Level 4 = 80% capacity • Level 5 = 100% capacity

You can use this type of control to combine VRV/ERQ with 3rd party AHUs, if you need supply temperature control

What are the benefits? When to use this type of control? Looks very similar to X-control…

The benefits are: • Direct temperature control (capacity is changed as a function of measured temperature) • Most standard AHU controllers are suitable without additional programming • Due to variable refrigerant temperature no cold/hot drafts But: • Slower response to load variation -> room temperature fluctuation, less accurate temperature control (compared to X-Control), because of longer control sequence: W-Control

X-Control Measure

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Adjust capacity

Measure

Set target T

This is the only possible mode in multi-AHU or VRV indoors + AHU configurations. EXV control (depending on Tset-Tr(or Ts)

Z-control – how it works?

Daikin or 3rd Party Thermistor

Measures room temperature, sends ON/OFF signal to control box when set point is reached

EKEXV EV box

EKEQM Superheat/subcool information Capacity command

Room or supply air temperature information

Settings, incl. Tset (set point temperature)

BRC1(D,E) Works the same as ‘normal’ VRV indoor unit (cooling and heating):

•

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Adjust capacity (fine tune)

Title - Internal use only

TEMPERATURE CONTROL MODES

•

Reach target T

Outdoor unit What are the benefits? When to use this type of control?

Used to control the system and make the necessary settings

Tr(Ts)-Tset ↑ -> EXV opening ↑, outdoor unit capacity ↑ (superheat/subcool decrease) -> more refrigerant flow, more capacity. Tr(Ts)-Tset ↓ -> EXV opening ↓, outdoor unit capacity ↓ (superheat/subcool increase) -> less refrigerant flow, less capacity.

•

Cheap and simple solution, no need to use the additional controllers, etc. • You can combine VRV units and AHUs in one system, or connect several AHUs to 1 outdoor unit. • No supply temperature control, comfort conditions can be affected by hot/cold drafts You can use this mode if there is no particular supply temperature required or you want to combine VRV indoors and AHUs in one system.

Title - Internal use only

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NECESSARY COMPONENTS AND LIMITATIONS What do I need for pair application (coil capacity ≤ 25 kW)? • To control the temperature of the air leaving or returning to the AHU, by means of an external DDC device (X and W control) • To control indirectly the room air temperature by fixing Te or Tc (Y control)

• To control the temperature of the returning air to AHU by means of a Daikin controller (Z control)

EKEQFCBA

EKEQD EKEXV class

EKEXV Expansion Valve

EKEQ* Control Box

63 80

communication

100 125 140

EXV control

200 250

Max +/-30 m

DDC Controller Min 5 m, max. 50 m R410A liquid

Max +/-5 m

0-10 V

Air Handling Unit (AHU)

Max. 5 m

Thermistors

R410A gas

ERQ/VRV IV Heat Pump 8 and 10 HP 19

Title - Internal use only

NECESSARY COMPONENTS AND LIMITATIONS What do I need for pair application (coil capacity > 25 kW)? • To control the temperature of the air leaving or returning to the AHU, by means of an external DDC device (X and W control) • To control indirectly the room air temperature by fixing Te or Tc (Y control)

EKEQFCBA

EKEQ* Control Box

EKEXV Expansion Valve

communication

EKEXV class 200 250

Min 5 m, max. 50 m R410A liquid

500

Max +/-5 m

DDC Controller

400

EXV control

Max +/-30 m

0-10 V

Air Handling Unit (AHU)

Max. 5 m

Thermistors

R410A gas

VRV IV Heat Pump CH/Non-CH Water cooled VRV 20

Title - Internal use only

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NECESSARY COMPONENTS AND LIMITATIONS What do I need for pair application (coil capacity more than 50 kW, multi-circuit)? VRV IV Heat Pump CH/Non-CH Water cooled VRV

• • •

Supply air (or return air) temperature control (X, Y, W)

F 1F 2

F 1F 2

F 1F 2

EKEXV class

EKEQFCBA

63

EKEQFCBA

EXV control

80

Max 3 DX kits/AHU Connection ratio between 90~110% Temperature control by DDC (0-10 V signal)

EXV control

EKEQFCBA

EXV control

0-10 V

100

DDC Controller

125 140 200 250 400 500

Interlaced coil (max. 3 circuits). Max. capacity = 50 kW x 3 = 150 kW Thermistors

Piping length limitations are the same as for single circuit coils: • OU → (each) EXV kit = 5..50 m • EXV kit → AHU = 5 m max. • Level difference between OU and AHU = 30 m max. 21

Title - Internal use only

NECESSARY COMPONENTS AND LIMITATIONS What do I need for multi application (several AHUs in one circuit)? • • •

BRC1(D,E)

Connection ratio is limited between 90~110% Unlimited number of DX kits/AHUs within connection ratio Control by iTM II and/or local Daikin controllers (MANDATORY)

P1P2 EKEQMCBA EKEXV class

VRV IV Heat Pump CH/Non-CH Water cooled VRV

63

EKEXV

125

F1 F2

EKEXV

F1 F2

Only return air temperature control (Z) is possible. Like VRV indoor units.

80 100 140 200 250 400

EKEQMCBA

500

P1P2

Piping length limitations: • EXV kit → AHU = 5 m max. • The rest are the same as for “normal” VRV application (check VRV data book/installation manual)

BRC1(D,E) AHU DX coils. Number of circuits is theoretically unlimited.

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NECESSARY COMPONENTS AND LIMITATIONS What do I need for multi application (AHUs and VRV indoors in one circuit)? •

Only return air temperature control (Z) is possible. VRV IV Heat Pump CH/Non-CH Water cooled VRV VRV IV Heat Recovery

• •

• • •

AHU DX coil (theoretically unlimited number of circuits)

Conditions: Unlimited DX kits/AHUs (within connection ratio) Connection ratio between 50~110% VRV indoors should be min 50% ratio Control by iTM II and/or individual wired remote controllers (MANDATORY)

EKEQMCBA

EKEXV EXV control P1P2

F 1F 2

F 1F 2 F 1F 2

VRV Indoors are mandatory in this case! Hydrobox connection is not possible!

F 1F 2 VRV IU

VRV IU P1P2

BRC1(D,E)

VRV IU P1P2

P1P2

BRC1(D,E) BRC1(D,E) BRC1(D,E) Piping length limitations: • EXV kit → AHU = 5 m max. • The rest are the same as for “normal” VRV application (check VRV data book/installation manual) 23

Title - Internal use only

NECESSARY COMPONENTS AND LIMITATIONS What other possibilities do I have? Outdoor

Only Z-Control

Coil (multicircuit)

Outdoor 1

Only Z-Control DX Kit 1

DX Kit 1

DX

EKEQMCBA EKEXV DX

EKEQMCBA EKEXV Coil (multicircuit)

EKEQMCBA EKEXV Outdoor N

EKEQMCBA EKEXV

DX Kit 2

DX Kit 2

EKEQMCBA EKEXV EKEQMCBA EKEXV

DX Kit N

DX Kit N

If for some reason you need to work with more than 3-circuit coil with one outdoor unit, it is possible, but only in Z control mode.

You can also connect several outdoor units to 1 multi-circuit coil, but only in Z control mode. Thus you can obtain theoretically unlimited capacity.

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COIL REQUIREMENTS How to select DX coil properly? Is the coil selected by AHU selection software suitable for VRV application? AHU DX coils

Single circuit

Capacity ≤ 50 kW YES

NO Multi-circuit

All these coil types you may get from AHU selection software

With face control

No special requirements

Only this solution is allowed for multi-circuit coils application!

With row control

Interlaced

Circuit 1

Circuit 1

Circuit 1

Circuit 2

Circuit 2

Circuit 2

Problems: •

Temperature stratification at partial load -> comfort issues

Benefits: • Simple construction, cheap

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Problems: •

Not possible to reach coil capacity balance -> reliability issues

Benefits: • Simple construction, cheap, compact

Problems: •

Complex construction

Benefits: • Even leaving air temperature • Coil capacity balanced

Title - Internal use only

Thank you

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