Heat pump system with extended run time boost compressor

Abstract

A heat pump system is disclosed that utilizes a primary compressor, a booster compressor, and a controlled heat exchanger heat exchanger fluidly connected between the boost compressor output and the primary compressor input. The controlled heat exchanger functions to reduce the temperature of the refrigerant entering the primary compressor, thereby allowing the booster compressor to operate for longer periods without overheating the primary compressor. Increasing compressor run times improves both the heat pump efficiency and extends the compressor lifespan. The heat energy may be diverted away from the primary compressor to a hydronics system for heating an indoor space. Additionally, heat energy may be withdrawn from the hydronics system to defrost the outdoor coil of the heat pump system. The periods of compressor inactivity may also be extended by withdrawing heat energy stored in a hydronics tank.

1 . A heat pump system comprising:
 a primary compressor having a primary refrigerant inlet;   a boost compressor having a boost refrigerant outlet, the primary and boost compressors arranged in series;   a refrigerant conduit system with a refrigerant moving from the boost refrigerant outlet to the primary refrigerant inlet;   a controllable heat removal means fluidly connecting between the boost refrigerant outlet and the primary refrigerant inlet; and   a controlling means regulating a heat removal rate from the heat removal means.   
   
   
       2 . The heat pump system of  claim 1  further comprising
 an accumulator, a refrigerant flowing from the heat removal means to the accumulator to the primary refrigerant inlet.   
   
   
       3 . The heat pump system of  claim 1  wherein
 the controllable heat removal means includes a heat exchanger, a hydronics tank, and a hydronics conduit system with a pump;   the hydronics conduit system connecting the hydronics tank and the heat exchanger.   
   
   
       4 . The heat pump system of  claim 3  wherein
 the controlling means deactivates the pump when the boost compressor is inactive.   
   
   
       5 . A heat pump system for heating an indoor space comprising:
 an indoor primary compressor,   an indoor boost compressor,   an outdoor heat exchanger,   an indoor heat exchanger, and   a refrigerant flowing from the outdoor heat exchanger to the boost compressor to the indoor heat exchanger to the primary compressor and back to the outdoor heat exchanger.   
   
   
       6 . The heat pump system of  claim 5  further comprising
 the indoor heat exchanger having a first conduit system and a second conduit system, the refrigerant flowing through the first conduit system, and   a heat transfer fluid flowing through the second conduit system.   
   
   
       7 . The heat pump system of  claim 6  wherein
 the heat transfer fluid consists essentially of water.   
   
   
       8 . The heat pump system of  claim 6  further comprising
 a hydronics system, the heat transfer fluid also flowing through the hydronics system.   
   
   
       9 . The heat pump system of  claim 5  further comprising
 an additional compressor,   the refrigerant flowing from the indoor heat exchanger to the additional compressor to the indoor heat exchanger.   
   
   
       10 . The heat pump system of  claim 5  further comprising:
 a refrigerant flowing from the outdoor heat exchanger to the indoor boost compressor and an indoor additional compressor;   the refrigerant further flowing from the indoor boost compressor and the indoor additional compressor to the indoor heat exchanger;   the refrigerant further flowing from the indoor heat exchanger to the indoor primary compressor to an oil separator;   the refrigerant further flowing from the oil separator through an indoor water tank heat exchanger to a hydronics heat exchanger;   the refrigerant further flowing from the hydronics heat exchanger through a condenser to the outdoor heat exchanger;   a hydronics conduit system connecting the hydronics heat exchanger and the indoor heat exchanger to a hydronics tank, the hydronics tank fluidly connected to a radiant heating system for heating the indoor space;   a water tank conduit system connecting the indoor water tank heat exchanger to a water tank, the water tank providing heated water for the indoor space;   a blower blowing air on the condenser, the blower and condenser providing forced air heating for the indoor space; and   a controller regulating the flow of refrigerant with a plurality of valves.   
   
   
       11 . A heat pump system comprising:
 a primary compressor having a primary inlet and a primary outlet,   a booster compressor having a refrigerant boost inlet and a boost outlet,   a first heat exchanger, and   a refrigerant flowing
 from the boost outlet to the first heat exchanger, 
 from the first heat exchanger to the primary inlet, and 
 from the primary outlet to the boost inlet; 
   the refrigerant proximal to the primary outlet having a first pressure,   the refrigerant proximal to the boost inlet having a second pressure,   the refrigerant proximal to the primary inlet having a third pressure,   the first pressure greater than the second pressure, and   the third pressure greater than the second pressure.   
   
   
       12 . The heat pump system of  claim 11  further comprising:
 a heat transfer fluid,   the first heat exchanger including a first conduit system and a second conduit system,   the refrigerant flowing through the first conduit system, and   the heat transfer fluid flowing through the second conduit system.   
   
   
       13 . The heat pump system of  claim 12  further comprising
 a hydronics tank, the heat transfer fluid flowing through the hydronics tank.   
   
   
       14 . The heat pump system of  claim 11  further comprising:
 an accumulator,   the refrigerant further flowing from the first heat exchanger to the accumulator to the primary inlet.   
   
   
       15 . The heat pump system of  claim 11  further comprising:
 an additional compressor having an additional inlet and an additional outlet,   the refrigerant further flowing from the additional outlet to the first heat exchanger,
 from the primary outlet to the additional inlet; 
 the refrigerant proximal to the additional inlet having a fourth pressure, 
 the fourth pressure being substantially equal to the second pressure. 
   
   
   
       16 . The heat pump system of  claim 11  wherein
 the boost compressor is a variable speed compressor.   
   
   
       17 . A method of defrosting a heat pump system, the heat pump comprising:
 a first heat exchanger with a first refrigerant input and a first refrigerant output;   a second heat exchanger connected in series with the first heat exchanger;   an outdoor heat exchanger and a reversible valve;   a conduit system connecting the first heat exchanger, the second heat exchanger, the outdoor heat exchanger, and the reversible valve, the conduit system circulating a refrigerant to the first heat exchanger, the second heat exchanger, the outdoor heat exchanger, and the reversible valve;   a bypass line with a bypass valve, the bypass line connecting to the first refrigerant input and the first refrigerant output of the first heat exchanger;   the method comprising:
 opening the bypass valve to divert the refrigerant around the first heat exchanger; 
 reversing the reversible valve to a first state such that the refrigerant flow through the second heat exchanger and the outdoor heat exchanger is reversed to provide the refrigerant heat energy from the second heat exchanger; 
 operating the heat pump system to defrost the outdoor heat exchanger with heat energy provided by the second heat exchanger; 
 reversing the reversible valve to a second state such that the refrigerant flow through the second heat exchanger and the outdoor heat exchanger is reversed to withdraw heat energy from the refrigerant at the second heat exchanger; 
 closing the bypass valve to return refrigerant flow to the first heat exchanger. 
   
   
   
       18 . The method of  claim 17  further comprising
 monitoring a temperature at the second heat exchanger with a temperature monitor; and   stopping the defrosting of the outdoor coil if the temperature is below a threshold limit.   
   
   
       19 . The method of  claim 17  wherein
 the step of engaging the bypass valve occurs at the expiration of a defrost controller.   
   
   
       20 . The method of  claim 17  wherein
 the step of operating the heat pump system further comprises withdrawing heat energy from the second heat exchanger to provide heat energy to the outdoor heat exchanger.   
   
   
       21 . A heat pump system for heating an indoor space comprising:
 an first indoor heat exchanger with a first refrigerant input line and an first refrigerant output line, a bypass line with a bypass valve, a second indoor heat exchanger, an outdoor heat exchanger, and a reversible valve;   the bypass line connecting to the first refrigerant input line and the first refrigerant output line of the first heat exchanger;   a first conduit system connecting the first indoor heat exchanger, the second indoor heat exchanger, the outdoor heat exchanger, and the reversible valve in series;   the first conduit system circulating a refrigerant to the first indoor heat exchanger, the second indoor heat exchanger, the outdoor heat exchanger, and the reversible valve;   a controller operable to control the heat pump system in a heating mode and a defrost mode;   the heat pump system in the heating mode operating the bypass valve in a closed state and the reversible valve in a first state to provide heating for the first indoor heat exchanger and the second indoor heat exchanger while absorbing heat energy at the outdoor heat exchanger; and   the heat pump system in the defrost mode operating the bypass valve in an open state and the reversible valve in a second state to transfer heat energy from the second indoor heat exchanger to the outdoor heat exchanger.   
   
   
       22 . The heat pump system of  claim 21  further comprising
 a heat transfer fluid and a radiant heating system   the heat transfer fluid flowing through second indoor heat exchanger and the radiant heating system.   
   
   
       23 . The heat pump system of  claim 21  further comprising
 a third indoor heat exchanger, a primary compressor, and a boost compressor;   the heat transfer fluid further flowing through the third indoor heat exchanger;   the refrigerant further circulating from the reversible valve to the boost compressor to the third heat exchanger to the primary compressor to the reversible valve.   
   
   
       24 . The heat pump system of  claim 21  further comprising
 the controller further operating to control the heat pump system in a cooling mode;   the heat pump system in the cooling mode operating the bypass valve in the closed state and the reversible valve in the second state to transfer heat energy from the first indoor heat exchanger to an outdoor heat exchanger.   
   
   
       25 . The heat pump system of  claim 21  further comprising:
 a first blower to direct indoor air into heat exchange relationship with the first heat exchanger to provide forced air heating for an indoor air space; and   a hydronics pump to direct a fluid into heat exchange relationship with the second heat exchanger to provide radiant heating for an indoor space.