活动和生产交换的不同结果

Question

在自行创建的活动上运行 LCA 时，我得到了非常奇怪的结果。该过程的分数类似于 1e24，但当我打印其交换的分数时，它们都在 1 左右，而生产交换（生产量为 1）的分数约为 8，这对我来说接近令人满意的值。有没有人遇到过这种问题或者可以解释我为什么会这样？非常感谢。

这是我在运行 Exchange 问题解决程序时得到的结果：（预期 0 个交换）

'_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None) ('E4T', '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu')
Exchange: 1 kg '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)' (kg, GLO, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('E4T', '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)')
Exchange: -0.0 kilogram 'treatment of scrap aluminium, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '3c59616fc3bbe826a4b678a7abcbc7f8')
Exchange: -0.0 kilogram 'treatment of scrap copper, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', 'f95ce693b0eccbf0bff1efaa6404e948')
Exchange: -1.1624999999999999 kilogram 'treatment of scrap steel, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', 'ae90165b719e1d5f845e5009247a480c')
Exchange: -0.0 kilogram 'treatment of scrap tin sheet, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '8d000316c55847f883e812b730d1422e')
Exchange: -0.0 kilogram 'treatment of waste glass, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '6b89808f2ab32b667edec826e026b59d')
Exchange: -0.0 kilogram 'treatment of waste graphical paper, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '2435d4d0acc560df626e1c2a4e0d9d04')
Exchange: -0.0 kilogram 'treatment of waste paperboard, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', 'f9f40ac2f0c47b7c2ccb7decad31a8a3')
Exchange: -0.0 kilogram 'treatment of waste graphical paper, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '2435d4d0acc560df626e1c2a4e0d9d04')
Exchange: -0.0 kilogram 'treatment of waste graphical paper, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '2435d4d0acc560df626e1c2a4e0d9d04')
Exchange: -0.0 kilogram 'treatment of waste paint, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '697c8738655c959c8b7c1af8ff16ffb3')
Exchange: -0.0 kilogram 'treatment of waste plastic, mixture, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '94705189b5c5228845ef704da079eba8')
Exchange: -0.0 kilogram 'treatment of waste polyethylene, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '934b77606b3e7f9f42cfd7e009641168')
Exchange: -0.19375 kilogram 'treatment of waste polypropylene, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '6d47bd47868d34b291118e51ac922540')
Exchange: -0.0 kilogram 'treatment of waste polystyrene, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '0bc94608ea455a6da5c34aa09d5bd5f6')
Exchange: -0.0 kilogram 'treatment of waste polyurethane, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', 'db69868236255cb83d79da02d2bfae5d')
Exchange: -0.0 kilogram 'treatment of waste polyvinylchloride, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '860b4dba14c8ee9c46756957477235de')
Exchange: -3.7199999999999998 kilogram 'treatment of waste rubber, unspecified, municipal incineration' (kilogram, RoW, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '7d6e94bc691fd65ad47636e33ca19fb7')
Exchange: -0.0 kilogram 'treatment of waste textile, soiled, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', 'b2988f028678bae3feb3c091b4020ecd')
Exchange: -0.0 kilogram 'treatment of waste wood, untreated, municipal incineration' (kilogram, CH, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '4cf588e35ba44325bc1336bb60d02732')
Exchange: -0.0 kilogram 'treatment of municipal solid waste, incineration' (kilogram, FR, None) to '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)__pneu' (kg, GLO, None)>
     ('ecoinvent 3.6', '079723cdbfd0fa7d30e65f48af27e273')

当运行以下代码时：

method = [m for m in bw.methods if 'IPCC 2013' in str(m) and 'GWP 100a' in str(m) and not 'no LT' in str(m)][0]
score = y.LCA_calc_score(method,my_activity,1)
print(score)

for exc in my_activity.exchanges() :
    score = y.LCA_calc_score(method,exc.input,exc['amount'])
    print(score,exc.input,exc['type'])

我明白了：

-1.0311343621766253e+24
-0.5593820228176581 '_Municipal solid waste (waste scenario) {FR}| treatment of municipal solid waste, incineration | Cut-off, U (sans procédés obsolètes)' (kg, GLO, None) production
0.0 'treatment of scrap aluminium, municipal incineration' (kilogram, RoW, None) technosphere
0.0 'treatment of scrap copper, municipal incineration' (kilogram, RoW, None) technosphere
0.012501960171068006 'treatment of scrap steel, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of scrap tin sheet, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of waste glass, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of waste graphical paper, municipal incineration' (kilogram, RoW, None) technosphere
0.0 'treatment of waste paperboard, municipal incineration' (kilogram, RoW, None) technosphere
0.0 'treatment of waste graphical paper, municipal incineration' (kilogram, RoW, None) technosphere
0.0 'treatment of waste graphical paper, municipal incineration' (kilogram, RoW, None) technosphere
0.0 'treatment of waste paint, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of waste plastic, mixture, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of waste polyethylene, municipal incineration' (kilogram, CH, None) technosphere
0.49068734863333907 'treatment of waste polypropylene, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of waste polystyrene, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of waste polyurethane, municipal incineration' (kilogram, RoW, None) technosphere
0.0 'treatment of waste polyvinylchloride, municipal incineration' (kilogram, CH, None) technosphere
11.735510474450567 'treatment of waste rubber, unspecified, municipal incineration' (kilogram, RoW, None) technosphere
0.0 'treatment of waste textile, soiled, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of waste wood, untreated, municipal incineration' (kilogram, CH, None) technosphere
0.0 'treatment of municipal solid waste, incineration' (kilogram, FR, None) technosphere

（LCA_cal_score函数如下：）

def LCA_calc_score(self, method, process, amount):
        """
        Calculates the LCA score for given method and functional unit.
        
        : param : method = tuple, LCA method from Brightway
        : param : process = tuple, activity corresponding to the functional unit
        : param : amount = float, amount of the activity corresponding to the functional unit
        
        : return : lca.score = float, LCA score from the Brightway calculation
        
        """
        
        #Definition of the functional unit
        functional_unit = {process:amount}
        
        #Definition of the LCA
        lca = bw.LCA(functional_unit,method)
        #Use of the Brightway functions for the inventory and the impact assessment
        lca.lci()
        lca.lcia()
        
        return lca.score

Answer 1

您的活动(sans procédés obsolètes)__pneu 没有合理的生产交换。相反，有一个标记为production 的交换，但它是从 (sans procédés obsolètes) 到(sans procédés obsolètes)__pneu。生产交换来自同一活动。