蒸汽供暖一次性投入较小，但使用维护费用较大；
The initial costs of a steam heating system are relatively low, but the maintenance costs are high.
无耗材，无需维护，治疗成本几乎为零，一次性投入终生收益。
No supplies, no maintenance, cost of treatment is almost zero, a one-time investment in a lifetime income.
一次性投入建成冷库，使用寿命可达30年，经济效益十分显著。
One-time investment cold storage, service life can be built up to 30 years, and the economic benefit is remarkable.
应用推荐