Heat Recovery

Against the grim backdrop of a steady rise in global energy demand coupled with a relative and persistent decline in actual supply, energy conservation and emission reduction has become an imperative. Numerous factories are also constantly exploring potential avenues for energy saving, and compressed air systems hold enormous potential for significant energy savings.

VW heat exchange unit is equivalent to a complete heat exchange station and pressurization station, integrating the functions of heat exchange and pipe network pressure control. Its working principle is as follows: the primary-side heat medium enters the plate heat exchanger via the temperature control system, releases heat, and then is discharged into the condensate tank; the low-temperature secondary-side water is pumped into the plate heat exchanger by the circulating pump and then delivered out. A temperature sensor is installed at the secondary water outlet, which feeds back the temperature signal to the temperature control system to adjust the temperature control valve, thereby controlling the secondary-side outlet water temperature. The solenoid valve receives the pressure signal from the pressure sensor and automatically supplies city water to the pipe network for compensation. It stops water supply when the water pressure in the pipe network reaches a preset level. The ET tank can maintain the constant pressure and temperature of the pipe network through pressure stabilization.

Temperature control Valve

A temperature-controlled three-way valve maintains the set temperature or flow in a piping system by adjusting the valve opening to mix two fluid streams or to route them along the same path. It can also effectively reduce water hammer when the temperature reaches the point at which the heat-transfer medium to the heat exchanger would be shut off. Control signal can be 0-10V or 4-20ma, and the valve body material can be stainless steel, canbron stell or brass. and vwalve brand or honeywell brand can be choose.

Plate Heat Exchanger

A plate heat exchanger is a new type of high-efficiency heat exchanger assembled by stacking a series of metal plates with a specific corrugated shape. Thin rectangular channels are formed between the various plates, and heat exchange is conducted through these plates. It is an ideal device for liquid-liquid and liquid-vapor heat exchange, featuring high heat exchange efficiency, low heat loss, compact and lightweight structure, small floor space, easy installation and cleaning, wide application, and long service life. Under the same pressure loss condition, its heat transfer coefficient is 3 to 5 times higher than that of a shell and tube heat exchanger, its floor space is only one-third of the latter, and the heat recovery rate can be as high as over 90%. vwalve brand or AlfaLaval brand can be choose.

Water Pump

A water pump is a machine that conveys or pressurizes liquids. It transfers the mechanical energy of a prime mover or other external energy to the liquid to increase the liquid’s energy. It is mainly used to convey liquids including water, oil, acid-base solutions, emulsions, suspensions and liquid metals, and can also transport liquid-gas mixtures and liquids containing suspended solids. Impeller pumps are adopted here, which transfer energy through the interaction between rotating impellers and water. vwalve brand or Grundfos brand can be choose.

Electric Control Module

The electric control system adopts the programmable logic controller (PLC), which is mature and reliable and can realize multiple functions as required. It is equipped with the touch screen dedicatedly matched for PLC, and supporting both Chinese and English display. The module mainly controls the start and stop of circulating water pumps and the automatic water make-up of the system, and simultaneously monitors the water temperature of the system. Other components are of the Schneider brand, featuring safety, reliability and wide application.

WHRU Model No.
For water-cooled type air compressor:

Model number	Matching Air Compressor1 Power (KW)	Inlet/outlet Size (DN) 2	Heat Recovery (Kcal/h)	Water Output3(Temperature Difference 10℃)(m3/hour)	AC Voltage (V)	Recommended Matching Water Pump Power (KW)
WHRU200	160	DN 50	120000	12	380/460	2.2
WHRU300	220	DN 50	150000	15	380/460	2.2
WHRU350	250	DN 65	187500	18.5	380/460	3
WHRU400	300	DN 65	225000	25	380/460	3

1. Not only is it applicable to waste heat recovery from air compressors, but it can also be used anywhere heat exchange is needed, for example to heat or cool emulsified coolant. ↩︎
2. All inlet and outlet threads can be customized to BSTP or NPT upon request, or flanges can be made to ANSI standards. ↩︎
3. The flow rates and power above are calculated based on a post-heat-exchanger temperature difference of 10°C; this can be adjusted to meet the customer’s actual needs, for example by reducing the temperature difference to increase the flow. ↩︎

AHRU Model No.
For oil-cooled type air compressor:

An oil-cooled air compressor heat recovery unit is an energy-saving device that uses the high-temperature oil and the heat of the compressed gas generated during the compressor’s operation. Through efficient heat exchange, it makes full use of this heat energy. Based on the principle of energy exchange, it recovers the heat produced during the compressor’s operation, while also improving the compressor’s operating conditions, reducing the need to run the cooling fan, and lowering the temperature of the compressor’s lubricating oil. It is an efficient waste-heat recovery device.

Model number	Matching Air Compressor Power (KW)	Inlet/outlet Size (DN)	Heat Recovery (Kcal/h)	Water Output(Temperature Difference 40℃)(m3/hour)	AC Voltage (V)	Recommended Matching Water Pump Power (KW)
AHRU20	15	DN 32	11250	0.28	110/220	0.55
AHRU30	22	DN 32	16500	0.41	110/220	0.55
AHRU50	37	DN 32	27750	0.69	110/220	0.55
AHRU75	55	DN 32	41250	1.03	110/220	0.75
AHRU100	75	DN 32	56250	1.41	380/460	0.75
AHRU125	90	DN 32	67500	1.68	380/460	0.75
AHRU150	110	DN 40	82500	2.06	380/460	1.1
AHRU175	132	DN 40	99000	2.47	380/460	1.1