Blancher water heated with refrigeration heat
How a frozen vegetable plant blanching 21 tonnes a day can heat its blancher with a heat pump fed from its ammonia freezing plant, instead of a furnace-oil boiler.
▶Video: Waste-heat recovery heat pumps
V10 · 2–2.5 minLifting warm water from condensers, effluent and process cooling to useful heat
Video coming soon01Problem statement
- Blanching and freezing at the same time. The plant heats product to 85–95 °C and then freezes it minutes later, so it pays for both heating and cooling.
- Open blancher losses. Water blanchers lose heat from the surface and through overflow make-up all shift.
- Temperature affects quality. Under-blanching leaves active enzymes. Over-blanching softens texture and dulls colour.
- Losses between fuel and process. Burning furnace oil in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference plant makes IQF peas, sweet corn and mixed vegetables. It blanches about 1.5 tonnes an hour over 14 hours, then cools and freezes product in an IQF tunnel. A large ammonia plant runs whenever the line runs.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Product heating in blancher | 20 → 85 °C | 1.5 t/h × 14 h = 21,000 kg | 1,403 |
| Blancher surface losses | 92 °C | 4 m² open surface × 2.4 kW/m² × 14 h | 134 |
| Blancher make-up water | 25 → 95 °C | 3,000 L/day | 244 |
| Storage and pipework standing losses | – | about 5% | 89 |
| Total useful heat | 1,870 | ||
Averaged over 18 running hours, the heat pumps need about 104 kW.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 4 × SE-WWUHT-27 (108 kW total) (SE-WWUHT water-source, R245fa) delivering 100 °C, covering the day's 1,870 kWh in about 17.3 running hours.
- A 3,500 L insulated storage tank decouples the heat pumps from the process peaks.
- Heat source: ammonia desuperheater and oil-cooler water at about 50 °C. Taking superheat out of the ammonia lowers condenser load and can trim compressor power.
- The furnace-oil fired steam boiler stays connected behind a normally closed valve as standby.
- A desuperheater and oil cooler on the ammonia compressors warm a water loop to about 50 °C. The water-source heat pump lifts this to about 100 °C.
- Blancher water recirculates through a plate exchanger heated from the hot-water tank, replacing direct steam injection.
- Fresh make-up water is preheated before it enters the blancher.
Selected equipment
| Model | SE-WWUHT-27 × 4 |
|---|---|
| Heating capacity | 27 kW each, 108 kW total |
| COP | 2.8 estimated for a 50 °C source (the data sheet is rated on a 60/55 °C source) |
| Rating | water or steam to 120 °C, R245fa |
| Supply temperature | 100 °C |
| Storage | 3,500 L insulated tank |
Capacity is sized from the heat demand above. COP is an estimate until Sunniva engineering confirms the design.
Control philosophy
TT-101 at the tank top starts the heat pump below 95 °C and stops it at 100 °C. TIC-201 holds blancher water at 92 °C. TIC-202 holds make-up at 95 °C. If blancher temperature falls below set point, the existing steam injection valve opens as standby.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per tonne of vegetables | – | – |
| CO₂ per year | – | – |
06Benefits
Freezing plant heat reused
Heat from the ammonia plant blanches the next batch of vegetables.
Accurate blanching
Hot water through an exchanger holds blancher temperature closer than live steam.
Runs with the season
Heat demand and refrigeration heat appear together, so the source is there when needed.
Lower energy cost
Each kWh of electricity delivers about 2.8 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
No flame on site
No burner, flue or fuel tank for this duty, and no fuel deliveries to schedule.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Products, blanching time and temperature
- Line rate and hours per day in season
- Blancher type, surface area and make-up rate
- Ammonia compressor capacity and discharge temperature
- Season length
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Source sizing. Desuperheat and oil cooling give only 15–20% of the condenser heat. Check compressor data. Condenser water can supplement at a lower COP.
- Starch and debris. Blancher water carries starch and skins. Use an open-able plate exchanger with a strainer, and plan regular cleaning.
- Peroxidase test. Confirm blanching adequacy by peroxidase test after commissioning.
- Source stream. The source must give up roughly two-thirds of the heat delivered. Confirm its flow and temperature over a full production day, and filter it before the evaporator.
- Water quality. Scale forms quickly above 60 °C. Use softened make-up and keep the heat pump loop closed, with process fluids on the far side of an exchanger or coil.
- Performance figure. The COP on this page is an engineering estimate, not a data sheet value. Sunniva engineering will confirm it for the actual source and supply temperatures.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.
Talk to us
Blancher water heated with refrigeration heat
How a frozen vegetable plant blanching 21 tonnes a day can heat its blancher with a heat pump fed from its ammonia freezing plant, instead of a furnace-oil boiler.
▶Video: Waste-heat recovery heat pumps
V10 · 2–2.5 minLifting warm water from condensers, effluent and process cooling to useful heat
Video coming soon01Problem statement
- Blanching and freezing at the same time. The plant heats product to 85–95 °C and then freezes it minutes later, so it pays for both heating and cooling.
- Open blancher losses. Water blanchers lose heat from the surface and through overflow make-up all shift.
- Temperature affects quality. Under-blanching leaves active enzymes. Over-blanching softens texture and dulls colour.
- Losses between fuel and process. Burning furnace oil in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference plant makes IQF peas, sweet corn and mixed vegetables. It blanches about 1.5 tonnes an hour over 14 hours, then cools and freezes product in an IQF tunnel. A large ammonia plant runs whenever the line runs.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Product heating in blancher | 20 → 85 °C | 1.5 t/h × 14 h = 21,000 kg | 1,403 |
| Blancher surface losses | 92 °C | 4 m² open surface × 2.4 kW/m² × 14 h | 134 |
| Blancher make-up water | 25 → 95 °C | 3,000 L/day | 244 |
| Storage and pipework standing losses | – | about 5% | 89 |
| Total useful heat | 1,870 | ||
Averaged over 18 running hours, the heat pumps need about 104 kW.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 4 × SE-WWUHT-27 (108 kW total) (SE-WWUHT water-source, R245fa) delivering 100 °C, covering the day's 1,870 kWh in about 17.3 running hours.
- A 3,500 L insulated storage tank decouples the heat pumps from the process peaks.
- Heat source: ammonia desuperheater and oil-cooler water at about 50 °C. Taking superheat out of the ammonia lowers condenser load and can trim compressor power.
- The furnace-oil fired steam boiler stays connected behind a normally closed valve as standby.
- A desuperheater and oil cooler on the ammonia compressors warm a water loop to about 50 °C. The water-source heat pump lifts this to about 100 °C.
- Blancher water recirculates through a plate exchanger heated from the hot-water tank, replacing direct steam injection.
- Fresh make-up water is preheated before it enters the blancher.
Selected equipment
| Model | SE-WWUHT-27 × 4 |
|---|---|
| Heating capacity | 27 kW each, 108 kW total |
| COP | 2.8 estimated for a 50 °C source (the data sheet is rated on a 60/55 °C source) |
| Rating | water or steam to 120 °C, R245fa |
| Supply temperature | 100 °C |
| Storage | 3,500 L insulated tank |
Capacity is sized from the heat demand above. COP is an estimate until Sunniva engineering confirms the design.
Control philosophy
TT-101 at the tank top starts the heat pump below 95 °C and stops it at 100 °C. TIC-201 holds blancher water at 92 °C. TIC-202 holds make-up at 95 °C. If blancher temperature falls below set point, the existing steam injection valve opens as standby.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per tonne of vegetables | – | – |
| CO₂ per year | – | – |
06Benefits
Freezing plant heat reused
Heat from the ammonia plant blanches the next batch of vegetables.
Accurate blanching
Hot water through an exchanger holds blancher temperature closer than live steam.
Runs with the season
Heat demand and refrigeration heat appear together, so the source is there when needed.
Lower energy cost
Each kWh of electricity delivers about 2.8 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
No flame on site
No burner, flue or fuel tank for this duty, and no fuel deliveries to schedule.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Products, blanching time and temperature
- Line rate and hours per day in season
- Blancher type, surface area and make-up rate
- Ammonia compressor capacity and discharge temperature
- Season length
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Source sizing. Desuperheat and oil cooling give only 15–20% of the condenser heat. Check compressor data. Condenser water can supplement at a lower COP.
- Starch and debris. Blancher water carries starch and skins. Use an open-able plate exchanger with a strainer, and plan regular cleaning.
- Peroxidase test. Confirm blanching adequacy by peroxidase test after commissioning.
- Source stream. The source must give up roughly two-thirds of the heat delivered. Confirm its flow and temperature over a full production day, and filter it before the evaporator.
- Water quality. Scale forms quickly above 60 °C. Use softened make-up and keep the heat pump loop closed, with process fluids on the far side of an exchanger or coil.
- Performance figure. The COP on this page is an engineering estimate, not a data sheet value. Sunniva engineering will confirm it for the actual source and supply temperatures.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.