热电联产(CHP)：联产遇上热回收

What CHP does

Combined Heat and Power (CHP), or cogeneration, produces electricity and useful heat from a single fuel source. Instead of venting engine or turbine exhaust and jacket heat, a CHP plant captures it for space heating, process steam, or domestic hot water – lifting total fuel efficiency from ~40% (grid power alone) to 75-90%.

Where air-to-air recovery fits

CHP处理高品位热回路（水／蒸汽）。但配套CHP的建筑仍通过通风排出空调空气。一个 空气-空气换热器 位于HVAC侧的设备捕捉剩余的低品位排热能量，补充CHP的水回路。

Typical applications

• 全年热需求稳定的医院和园区。
• 同时需要电力和工艺热的工业场所。
• 为多个建筑供热的区域供暖系统。

Sizing principle

CHP is most economic when the heat demand is continuous and matches the engine’s output. Oversized CHP that dumps heat wastes the advantage. Pair it with 废热回收基础：捕捉从高热到低热各个品位的废热。

Payback and carbon

在能源价格多变的背景下，匹配良好的CHP通常3~6年即可回收，并使现场CO2降低20~30%。请用以下方式验证： 投资回收期计算 在投入之前。

Matching heat grade to use

CHP produces high-grade heat as hot water or steam, which should serve the highest-temperature demands first: space heating distribution, domestic hot water, and any process load. Lower-grade ventilation exhaust is then handled by air-to-air recovery on the HVAC side. Treating heat in grade order, from the CHP loop down to the ventilation air, extracts the most value from every unit of fuel.

Operations and maintenance

A CHP plant is a continuously running engine, so its maintenance schedule and availability matter to the payback. Plan for periodic servicing, monitor engine efficiency, and ensure the heat-demand profile stays matched to output. A unit that frequently trips or dumps heat loses its advantage quickly. Regular reporting of fuel saved versus a grid-only baseline keeps the business case visible.

Layering with building-side recovery

Even with CHP, individual buildings still vent conditioned air. Adding local air-to-air exchangers reduces the ventilation load the CHP must cover and smooths the central plant duty. The two strategies are complementary rather than competing: CHP for high-grade central heat, air-to-air for distributed low-grade exhaust.

常见问题

Does CHP replace air-to-air heat recovery?
No. CHP handles the high-grade water or steam loop, while air-to-air recovery captures the low-grade ventilation exhaust. The two are complementary.

When is CHP most economic?
When heat demand is continuous and matches the engine output. An oversized unit that dumps heat wastes the advantage.

What payback periods are typical for CHP?
Well-matched systems often pay back in 3 to 6 years and cut site CO2 by 20 to 30 percent, but validate with a payback calculation first.

Which buildings suit CHP best?
Hospitals, campuses, and industrial sites with steady thermal demand, plus district heating schemes feeding multiple buildings.

常见问题

Does CHP replace air-to-air heat recovery?

No. CHP handles the high-grade water or steam loop, while air-to-air recovery captures the low-grade ventilation exhaust. The two are complementary.

When is CHP most economic?

When heat demand is continuous and matches the engine output. An oversized unit that dumps heat wastes the advantage.

What payback periods are typical for CHP?

Well-matched systems often pay back in 3 to 6 years and cut site CO2 by 20 to 30 percent, but validate with a payback calculation first.

Which buildings suit CHP best?

Hospitals, campuses, and industrial sites with steady thermal demand, plus district heating schemes feeding multiple buildings.