Food processing: ammonia HP recovers refrigeration reject heat to 80°C wash water
Anonymized slaughter-plant retrofit: ammonia mid-temp heat pump couples to existing ammonia refrigeration and displaces a gas boiler for wash/sanitation hot water.
Engineering data
- Case type
- Anonymized field reference
- Data status
- anonymized_field_reference
- Industry
- Food
- Source temperature
- 28–32°C
- Sink temperature
- 75–80°C
- Temperature lift
- ≈ 43 K
- Heating or cooling duty
- 380 kW
- Architecture
- Ammonia mid-temperature heat pump coupled via evaporative condenser interface
- Result status
- Gas boiler largely displaced for wash heat; refrigeration reject heat reused
- Key risk
- Ammonia safety; seasonal refrigeration load vs heat demand mismatch
- Existing system
- Natural-gas boiler for wash/sanitation heat; ammonia refrigeration reject heat dumped on evaporative condenser
- Refrigerant
- R717 (ammonia)
- COP
- 3.5–4
- Annual savings
- Reported ~54% daily heat-energy cost cut vs gas boiler; ~¥0.45 M/y class savings in public summary
- Estimated payback
- Reported ~2.3 years (static)
Project background
An East China food-processing site used a gas boiler for daily wash and sanitation heat while ammonia screw packs rejected condenser heat outdoors. Energy cost and unused reject heat motivated a heat-pump retrofit.
Source / inputs
Source: ammonia plant condenser heat near 30°C. Sink: ~20/80°C hot water. Unit heating capacity ~380 kW class, COP ~3.8 in the published parameter table. Customer identity omitted.
Heat pump solution
An ammonia mid-temp heat pump evaporates against refrigeration reject heat and rejects to the process hot-water loop, replacing the gas boiler for wash/sanitation duty while remaining compatible with the existing ammonia plant.
COP & savings
Published table: heating ~380 kW, input ~100 kW, COP ~3.8, 20/80°C water. Operating summary reports large daily OPEX cut versus gas. Independent site audit not performed by this site.
Investment / ROI notes
Public summary cites CAPEX on the order of ¥1 M and static payback ~2.3 years from annual OPEX savings—tariffs and hours are site-specific.