Packaged Domestic Hot Water Generator with Plate-Type Heat Exchanger and Storage Tank Energy Source: Boiler Water

Transcription

1 Packaged Domestic Hot Water Generator with Plate-Type and Storage Tank Energy Source: ENGINEERED DUPLEX ALLOY AquaPLEX Duplex Stainless Steel Tank with 25-year Corrosion Warranty Up to 6,000,000 Btuh Output 150 to 900 Gallon Storage Tanks Single-wall Brazed Plate s Double-wall Plate-and-Frame s Domestic Water Temperature to 180 F Skid-mounted with Factory Pre-assembled Piping A S M E U A S M E HLW Engineered Water ing Solutions

2 Hot Water Outlet ASHRAE compliant insulation Supply Clean-in-Place Fittings TempTrac Electronic Operating Control AquaPLEX Storage Tank Operating Thermostat Return Y-strainer Flow Diffusers Plate-type Circulator Cold Water Inlet Transfer Characteristics of Plate s Due to their unique heat transfer characteristics, plate-type heat exchangers excel when applied in lowtemperature boiler water loops. A plate-type exchanger, when supplied with 145 F boiler water, can produce 140 F domestic hot water while reducing boiler water return temperature to 100 F or lower. The is highly beneficial in condensing boiler systems where efficiency improves with reductions in both supply and return water temperature. By comparison, u-tube heat exchangers are typically sized for a 20 F difference between the entering boiler water temperature and the desired domestic hot water outlet temperature. In addition, the boiler return water cannot be lower than the domestic hot water outlet temperature. For example, to produce 140 F domestic hot water, a u-tube exchanger would require 160 F entering boiler water and return boiler water would be no less than 141 F; temperatures above the ideal range for condensing boilers. Domestic Water Outlet 140 F Inlet 145 F Domestic Water Inlet 40 F Outlet 100 F Inside the plate exchanger, counter-flows of boiler and domestic water maximize the temperature differentials and allow the temperatures of the opposing liquids to cross with boiler return water becoming colder than domestic outlet water.

3 Sequence of Operation Demand for hot water causes a temperature drop in the storage tank as cold makeup water displaces the hot water in the tank. The tank thermostat senses this temperature drop and signals the operator to energize the circulator. Cold domestic water flows through the heat exchanger, captures heat from the boiler water and returns to the storage tank. Flow diffusers reduce the velocity of water leaving and returning to the storage tank from the heat exchanger. This eliminates turbulence in the storage tank and preserves the natural temperature stratification, allowing delivery of 80% of the storage tank s capacity at the desired set point temperature. When tank temperature returns to the desired set point, the circulator is de-energized. If the installation includes an optional boiler water control valve, the electronic operator will energize and de-energize the valve. Boiler Water Supply Boiler Water Return ed Domestic Water Back to Tank Domestic Cold Water Makeup 140 Domestic Hot Water to Building Control Options Hot Water Outlet Hot Water Outlet Storage Tank Storage Tank Supply Supply Return Return Cold Water Inlet Cold Water Inlet No Control Valve Constant boiler water flow through the heat exchanger is acceptable because heat transfer to the domestic water is controlled entirely by the circulator between the tank and heat exchanger. Constant flow at the water heater is also a logical choice for boiler loops equipped with VFD pump controls because domestic hot water is a year-round requirement in continual need of boiler water flow. 2-Way Control Valve If the water heater is not utilized as the constant flow bypass in a VFD-equipped boiler loop and boiler flow is to be allowed only during a domestic water call for heat, the plate heat exchanger can be equipped with a motorized 2-way valve. In this configuration, the boiler water 2-way valve and the circulator are controlled by the TempTrac operator.

4 Double-Wall Performance with Different Temperatures Double-wall heat exchangers are plate-and-frame design. ASME Stamp: Section VIII Operating Pressure (boiler side): 150 psi (standard) 300 psi (optional) Operating Temperature (boiler side): 338 F maximum rating Maximum boiler water temperature when operating EZ Plate water heater is 185 F. Consult PVI for higher boiler water temperatures. Connections: 2" NPT Stainless Steel Gasket Material: EPDM Plate Material: Stainless Steel Warranty: 3-year Side Domes c Water Side 145 F Entering (Supply) ~ 100 F Leaving (Return) 40 F to 140 F Flow (gpm) Pressure Drop (psi) Recovery (gph) BTU Output , , , , , ,125, ,325, ,650, ,000, ,650,000 Side Domes c Water Side 160 F Entering (Supply) ~ 88 F Leaving (Return) 40 F to 140 F Flow (gpm) Pressure Drop (psi) Recovery (gph) BTU Output , , , ,049, ,424, ,799, ,149, ,648, ,248, ,298,280 For performance with other boiler water and domestic water conditions, refer to PVI web site. Domestic side standard temperature is 180 F max. Domestic side standard pressure is 150 psi max. For higher operating pressure, consult your PVI representative.

5 Single-Wall Performance with Different Temperatures Single-wall heat exchangers are brazed plate design. ASME Stamp: Section VIII Operating Pressure (boiler side): 435 psi max Operating Temperature (boiler side): 450 F maximum rating Maximum boiler water temperature when operating EZ Plate water heater is 185 F. Consult PVI for higher boiler water temperatures. Connections: 2" NPT Stainless Steel Brazing Material: Copper Plate Material: Stainless Steel Warranty: 3-year Side Domes c Water Side 145 F Entering (Supply) ~ 105 F Leaving (Return) 40 F to 140 F Flow (gpm) Pressure Drop (psi) Recovery (gph) BTU Output , , , , , , ,050, ,250, ,500, ,000,000 Side Domes c Water Side 160 F Entering (Supply) ~ 95 F Leaving (Return) 40 F to 140 F Flow (gpm) Pressure Drop (psi) Recovery (gph) BTU Output , , , , ,200, ,500, ,875, ,300, ,750, ,650,000 For performance with other boiler water and domestic water conditions, refer to PVI web site. Domestic side standard temperature is 180 F max. Domestic side standard pressure is 150 psi max. For higher operating pressure, consult your PVI representative.

6 ENGINEERED DUPLEX ALLOY EZ Plate water heaters use a storage tank that is fabricated from AquaPLEX duplex stainless steel. It is an engineered alloy that combines two different types of stainless steel; austenitic and ferritic, to create a material that captures the advantages of both. After the tank is completely fabricated, it is immersion pickle-passivated; a process that returns the duplex stainless steel to its original pristine condition. AquaPLEX is naturally immune to corrosion in hot potable water regardless of temperature and as a result requires no additional lining or any type of anode protection. Because there is no corrosion, an anode rod, whether sacrificial or impressed current, simply has nothing to do. Unlike 316L stainless steel, the addition of a ferritic grain structure renders the duplex stainless steel immune to chloride stress corrosion cracking; a known failure mode of 316L stainless steel in hot potable water. These properties allow PVI to provide an unprecedented 25-year tank corrosion warranty. Additionally, because there is no lining AquaPLEX tanks are maintenance-free and the water contacting surfaces are non-porous and do not absorb water. AquaPLEX can also withstand temperature elevation and hyper-chlorination methods if it s ever necessary to eliminate bacteria from the building s water system. Storage Tank is Equipped with Lead-Free Bronze Fittings All connections to the AquaPLEX tanks are made through removable cast-bronze fittings. This design avoids using lined steel fittings that are often the starting point for corrosion inside a water heater. There is also no galvanic corrosion because the bronze fittings are galvanically neutral to the AquaPLEX tank. Bolt-on Bronze Fitting O-ring Gasket More than one-quarter million of these removable bronze fittings are in service! Tank Wall

7 Packaged er Dimensions Tank Size (gallons) Maximum er Maximum Dimensions of Factory Packaged er Height (H) Width (W) Depth (D) For larger tank sizes, consult your PVI representative. Standard Equipment AquaPLEX storage tank. ASME stamped HLW for 150 psi MAWP Double-wall plate-and-frame or single-wall brazed-plate heat exchanger, ASME stamped ASME-rated pressure relief valve (on heat exchanger) ASME-rated temperature and pressure relief valve (on storage tanks) Clean-in-place valves for heat exchanger Bronze y-strainer with blow down valve on domestic water to the heat exchanger Bronze circulating pump Programmable electronic operating control with digital temperature readouts (BAS connectable via Modbus RTU) Immersion temperature limiting device (high limit control) Drain Valve D Optional Equipment Electronic low water cutoff Manual-reset, immersion temperature limiting device Temperature and pressure gauges 2-way boiler water control valve Y-strainer for boiler water Higher operating pressures for storage tanks and heat exchangers (consult PVI representative) W H

8 Configuring an EZ Plate Model Number ( ) L ( ) A-TRPF (plate-and-frame, double wall) A-TRBP (brazed plate, single wall) Storage tank size in gallons (consult PVI representative for larger storage tanks or horizontal tank configuration) L designates AquaPLEX storage tank exchanger model number Example model number: 1800 L 300A-TRPF Plate-and-Frame heat exchanger number 1800 connected to a 300 gallon AquaPLEX storage tank. PV Engineered Water ing Solutions