The main costs of a heat treatment workshop include heating electricity or gas, process gases (carrier gas, enriched gas, methanol, ammonia, nitrogen), cooling water, compressed air and equipment maintenance. Energy consumption monitoring is carried out by designing metering points in furnaces, generators and public auxiliary equipment, allocating consumption to furnaces and products, and identifying waste such as no-load, standby, and excessive gas supply. Cost reduction measures include reasonable selection and load matching, multiple gas production modes, optimization of process time, reduction of door opening losses and centralized gas supply.
- Cost composition: heating energy + process gas + public auxiliary + maintenance
- Measure first: measure the furnace, generator, and auxiliary equipment separately.
- Redistribution: Allocate products to products based on heat time and loading volume
- Common waste: no-load insulation, excessive air supply, low-load operation, air leakage
- Measures: load matching, multiple gas production modes, process optimization, centralized gas supply
Cost composition
| Category | Content |
|---|---|
| heating energy | Stoves and generators electric or gas |
| process gas | RX gas (gas + electricity), nitrogen, methanol, propane/natural gas enriched gas, ammonia |
| Gongfu | Cooling water, compressed air, quenching oil cooling, exhaust |
| maintain | Probe, thermocouple, catalyst, reaction tank, furnace lining |
| quality cost | Rework, scrap, inspection |
Metering point design
- per furnace: Electricity (or gas volume), main process gas flow;
- generator: Heating energy consumption, gas raw materials, gas production;
- Gongfu: Air compressor, cooling tower, exhaust;
- Workshop summary: Used for verification.
The metering data is connected to the monitoring system and associated with the furnaces by time.
Allocate costs to heats
Heat cost ≈ Σ (consumption at each measurement point during the heat time period × unit price) + public and auxiliary apportionment + maintenance conversion
Then allocate it to each product or per kilogram according to the loading capacity, so that the true costs of different products, different furnace types, and different processes can be compared.
Common waste
| Waste | Performance | Countermeasures |
|---|---|---|
| No-load insulation | The stove is still full of temperature and gas even when there is no material. | Develop standby cooling and flow rate reduction procedures |
| Oversupply | Carrier gas flow is chronically higher than required | Check the flow rate according to furnace conditions and repair leaks |
| Generator low load | Large generator runs for a long time with low output | Multiple gas production modes, multiple unit combinations, and reasonable selection |
| Air leakage | The consumption of enriched gas is too high | Check furnace doors, seals, and pipelines |
| process redundancy | The time set by "Insurance" is too long | Optimize time with simulation and verification |
| Opening loss | integral-quench furnace frequently opens the door | Optimize scheduling and reduce unnecessary door openings |
Energy Savings at Generator Level
The official website of Gosi Controls ENDOMATE™ introduces that its multiple gas production modes can reduce emissions and energy waste, and it has energy consumption monitoring and data traceability functions. The double furnace design allows single furnace operation at low load.
Energy saving at process level
- Use online diffusion calculation to end carburizing according to actual layer depth to avoid taking too long;
- Reasonably increase the carburizing temperature and shorten the time (taking into account quality);
- Optimize loading capacity and increase single furnace output;
- Waste heat recovery (such as quenching oil cooling, tempering furnace).
Frequently asked questions
Is centralized gas supply necessarily cheaper than methanol dripping?
Not necessarily, it depends on the scale of gas consumption, energy prices and equipment utilization. Calculations should be based on actual data while taking into account the hidden costs of hazardous chemicals management.
Can energy consumption data be used for carbon emissions accounting?
It can be used as basic data, but carbon emission accounting needs to determine emission factors and boundaries according to corresponding methodology.
Will cost reduction affect quality?
Cost reduction should be based on quality. Any process adjustments should be validated and executed under change management in a system such as CQI-9.