A method (100; 200) for cooling process plant water, the method comprising: (a) exchanging (101; 201) heat between a first process water stream and a liquid refrigerant within a first heat exchanger (301; 401) to lower the temperature of the process water stream, thereby partially vaporizing the refrigerant upon the exchange of heat with the first process water stream; (b) transferring (102; 202) the first process water from the first heat exchanger (301; 401) to one or more process plants (302; 402); (c) transferring the partially vaporized refrigerant from the first heat exchanger (301; 401) to a multiphase pump to increase the pressure of the partially vaporized refrigerant, wherein a multiphase pump is for pumping a medium that includes multiple phases to a higher pressure; (d) transferring the partially vaporized refrigerant from the multiphase pump to a second heat exchanger (304; 404); (e) exchanging heat between a second process water stream and the partially vaporized refrigerant within the second heat exchanger (304; 404) to decrease the temperature of the refrigerant; (f) transferring the second process water stream from the second heat exchanger (304; 404) to become the first process water stream entering the first heat exchanger (301; 401); (g) transferring the partially vaporized refrigerant from the second heat exchanger (304; 404) to a first expansion valve (305; 405) to lower the pressure and/or temperature of the refrigerant; (h) transferring the partially vaporized refrigerant from the first expansion valve (305; 405) to a vapor-liquid separator (306; 406) to separate the liquid phase from the vapor phase thereof, thereby generating a liquid refrigerant; (i) transferring the liquid refrigerant from the vapor-liquid separator (306; 406) to a second expansion valve (307; 407) to lower the temperature of the liquid refrigerant; and (j) transferring the refrigerant from the second expansion valve (307; 407) to the first heat exchanger (301; 401) to exchange heat with the first process water stream. (a) exchanging (101; 201) heat between a first process water stream and a liquid refrigerant within a first heat exchanger (301; 401) to lower the temperature of the process water stream, thereby partially vaporizing the refrigerant upon the exchange of heat with the first process water stream; (b) transferring (102; 202) the first process water from the first heat exchanger (301; 401) to one or more process plants (302; 402); (c) transferring the partially vaporized refrigerant from the first heat exchanger (301; 401) to a multiphase pump to increase the pressure of the partially vaporized refrigerant, wherein a multiphase pump is for pumping a medium that includes multiple phases to a higher pressure; (d) transferring the partially vaporized refrigerant from the multiphase pump to a second heat exchanger (304; 404); (e) exchanging heat between a second process water stream and the partially vaporized refrigerant within the second heat exchanger (304; 404) to decrease the temperature of the refrigerant; (f) transferring the second process water stream from the second heat exchanger (304; 404) to become the first process water stream entering the first heat exchanger (301; 401); (g) transferring the partially vaporized refrigerant from the second heat exchanger (304; 404) to a first expansion valve (305; 405) to lower the pressure and/or temperature of the refrigerant; (h) transferring the partially vaporized refrigerant from the first expansion valve (305; 405) to a vapor-liquid separator (306; 406) to separate the liquid phase from the vapor phase thereof, thereby generating a liquid refrigerant; (i) transferring the liquid refrigerant from the vapor-liquid separator (306; 406) to a second expansion valve (307; 407) to lower the temperature of the liquid refrigerant; and (j) transferring the refrigerant from the second expansion valve (307; 407) to the first heat exchanger (301; 401) to exchange heat with the first process water stream.