Combined heating and cooling system

Abstract

A heating system for heating a fluid received at an inlet, the system including a first heating device disposed in a first heated line branched from the inlet, wherein a first flow of the fluid through the first heated line is configured to be modulated by a first valve; a second heating device disposed in a second heated line branched from the inlet, wherein a second flow of the fluid through the second heated line is configured to be modulated by a second valve; and a bypass line and a third valve disposed in the bypass line, wherein a flow through the bypass line is configured to be modulated by the third valve, wherein the first and second heating devices and the first, second and third valve are configured to cooperate to heat the fluid at an outlet received from the first and second heated line and the bypass line.

What is claimed herein is: 
     
         1 . A heating system comprising:
 (a) a burner;   (b) a blower configured for causing a first fluid flow through said burner from an inlet to an outlet;   (c) a heat exchanger interposed in a path of the first fluid flow, said heat exchanger configured for receiving a second fluid flow at an inlet and exhausting the second fluid flow at an outlet, wherein heat exchange can occur between the first fluid flow and the second fluid flow;   (d) an internal recirculation path connecting said outlet of the second fluid flow with a first point of said inlet of the heat exchanger;   (e) an external recirculation path connecting said outlet of the second fluid flow with a second point of said inlet of the heat exchanger, wherein said second point is disposed downstream of said first point along the second fluid flow; and   (f) a pump disposed at a third point of said inlet of the heat exchanger, wherein said third point is disposed downstream of said second point along the second fluid flow,   wherein the temperature of the second fluid flow is increased by at least one of the following operating modes of said heating system: (i) said pump is turned on to circulate the second fluid flow through at least one of said internal recirculation path and said external recirculation path, said blower is turned on to cause the first fluid flow which causes heat transfer from the first fluid flow via said heat exchanger to the second fluid flow; and (ii) said pump is turned on to circulate the second fluid flow through at least one of said internal recirculation path and said external recirculation path, said blower is turned on to cause the first fluid flow which causes heat transfer from the first fluid flow via said heat exchanger to the second fluid flow;   and said burner is turned on to cause heat transfer from said burner via said heat exchanger to the second fluid flow.   
     
     
         2 . The heating system of  claim 1 , further comprising a space heating and space conditioning system comprising a heat pump interposed between said first point and said second point along the second fluid flow, wherein said heat pump is configured to supply heat to the second fluid flow in a space cooling mode of said heat pump and to draw heat from the second fluid flow in a space heating mode of said heat pump. 
     
     
         3 . The heating system of  claim 1 , further comprising a valve interposed within said internal recirculation path for controlling the size of the second fluid flow through said internal recirculation path. 
     
     
         4 . The heating system of  claim 1 , further comprising a valve interposed within said external recirculation path for controlling the size of the second fluid flow through said external recirculation path. 
     
     
         5 . The heating system of  claim 1 , further comprising a check valve interposed within said internal recirculation path for preventing a bypass flow through said internal recirculation path to said external recirculation path. 
     
     
         6 . The heating system of  claim 1 , further comprising a heat storage tank interposed between said first point and said second point, wherein said heat storage tank is configured to store heat communicated from the second fluid flow. 
     
     
         7 . The heating system of  claim 6 , further comprising a solar collector functionally coupled to said heat storage tank.