Indirect heated hot water systems

Abstract

An indirect hot water system is provided with a secondary heat exchanger ( 130 ) that heats potable water upstream of the main heating tank ( 110 ). The secondary heat exchanger utilises refrigerant that has passed through the main heating tank. The system includes clips ( 40, 42, 60, 62 ) that support and separate the coils of the heat exchangers ( 108, 116 ) in the main tank ( 110 ) to increase the efficiency of the heat exchangers and the system overall. A pressure control valve maintains a substantially constant pressure and limits refrigerant flow in the secondary heat exchanger to maintain a high refrigerant temperature when the system is not operating at full capacity.

1 . A heat exchange system that transfers heat between a first fluid and a second fluid, the system including: 
 a first heat exchanger including: 
 a first inlet for the first fluid;  
 a second inlet for the second fluid;  
 a first outlet for the first fluid;  
 a second outlet for the second fluid; and  
   a constant pressure valve located downstream of the first heat exchanger and having a fifth inlet in fluid communication with the first outlet of the first heat exchanger that maintains a substantially constant pressure at the fifth inlet.    
   
   
       2 . The system of  claim 1  including a second heat exchanger having: 
 a third inlet for the first fluid;    a fourth inlet for the second fluid;    a third outlet for the first fluid;    a fourth outlet for the second fluid,    wherein, the third inlet is located downstream of the first outlet and the second inlet is located downstream of the fourth outlet.    
   
   
       3 . The system of  claim 2  wherein the constant pressure valve is located downstream of the third outlet.  
   
   
       4 . The system of  claim 1  wherein the first heat exchanger is an indirect heat exchanger utilising a third fluid to transfer heat from the first fluid to the second fluid.  
   
   
       5 . The system of  claim 1  wherein the first heat exchanger includes: 
 a tank;    a third fluid within the tank;    at least one first pipe extending between the first inlet and first outlet and extending at least partially within the third fluid, and    at least one second pipe extending between the second inlet and second outlet and extending at least partially within the third fluid.    
   
   
       6 . The system of  claim 5  including at least one hollow reservoir within the first tank, said at least one reservoir being at least partially immersed in the third fluid, the interior of at least one reservoir being in fluid communication with at least one of the second inlet and the second outlet.  
   
   
       7 . A heat exchange system that transfers heat between a first fluid and a second fluid, the system including: 
 a first heat exchanger including: 
 a tank;  
 a third fluid within the tank;  
 a first inlet for the first fluid;  
 a second inlet for the second fluid;  
 a first outlet for the first fluid;  
 a second outlet for the second fluid;  
 at least one first pipe extending between the first inlet and first outlet and extending at least partially within the third fluid, and  
 at least one second pipe extending between the second inlet and second outlet and extending at least partially within the third fluid; and  
   a second heat exchanger including: 
 a third inlet for the first fluid;  
 a fourth inlet for the second fluid;  
 a third outlet for the first fluid;  
 a fourth outlet for the second fluid,  
   wherein, the third inlet receives first fluid from the first outlet and the second inlet receives second fluid from the fourth outlet.    
   
   
       8 . The system of  claim 7  including a constant pressure valve located downstream of the first heat exchanger and having a fifth inlet in fluid communication with the first outlet of the first heat exchanger for maintaining a substantially constant pressure at the fifth inlet.  
   
   
       9 . The system of  claim 8  wherein the constant pressure valve is located downstream of the third outlet.  
   
   
       10 . The system of  claim 7  further including at least one hollow reservoir within the first tank, said at least one reservoir being at least partially immersed in the third fluid, the interior of at least one reservoir being in fluid communication with at least one of the second inlet and the second outlet.  
   
   
       11 . A heat exchange system that transfers heat between a first fluid and a second fluid, the system including: 
 a first heat exchanger including: 
 a first inlet for the first fluid;  
 a second inlet for the second fluid;  
 a first outlet for the first fluid;  
 a second outlet for the second fluid; and  
   a second heat exchanger including: 
 a third inlet for the first fluid;  
 a fourth inlet for the second fluid;  
 a third outlet for the first fluid;  
 a fourth outlet for the second fluid,  
 the third inlet receiving first fluid from the first outlet and the second inlet receiving second fluid from the fourth outlet, and  
 a constant pressure valve located downstream of the first heat exchanger and having a fifth inlet in fluid communication with the first outlet of the first heat exchanger for maintaining a substantially constant pressure at the fifth inlet.  
   
   
   
       12 . The system of  claim 11  wherein the constant pressure valve is located downstream of the third outlet.  
   
   
       13 . The system of  claim 11  wherein the first heat exchanger is an indirect heat exchanger utilising a third fluid to transfer heat from the first fluid to the second fluid.  
   
   
       14 . The system of  claim 11  wherein the first heat exchanger includes: 
 a tank;    a third fluid within the tank;    at least one first pipe extending between the first inlet and first outlet and extending at least partially within the third fluid, and    at least one second pipe extending between the second inlet and second outlet and extending at least partially within the third fluid.    
   
   
       15 . The system of  claim 14  further including at least one hollow reservoir within the first tank, said at least one reservoir being at least partially immersed in the third fluid, the interior of at least one reservoir being in fluid communication with at least one of the second inlet and the second outlet.