Methods and apparatus for operating a refrigeration unit
First Claim
1. A method of operating a refrigeration unit having a compressor driven by a liquid cooled prime mover, and an economizer cycle which enhances cooling and heating cycles initiated to control the temperature of a conditioned space to a predetermined set point temperature, with the enhancing of the heating cycle including adding heat to the economizer cycle from liquid used to cool the prime mover, comprising the steps of:
- sensing the temperature of the liquid which cools the prime mover,initiating a heating cycle when required, when the sensing step detects the temperature of the liquid is above a predetermined value,and initiating a special refrigeration cycle when a heating cycle is required, prior to the step of initiating the heating cycle, when the sensing step detects the temperature is not above the predetermined value,said step of initiating the special cycle including the step of increasing the load on the prime mover, at least until the sensing step detects that the temperature of the liquid is above the predetermined value.
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Accused Products
Abstract
A refrigeration unit of the type having an economizer cycle driven by a prime mover cooled by a liquid coolant. Electrical control configures refrigerant flow paths of the unit to provide heating and cooling cycles, as required to control the temperature of a conditioned space to a predetermined set point temperature. Heat from the liquid coolant is used to enhance the heating cycle. A heating cycle is initiated immediately, when required, when the temperature of the liquid coolant is above a predetermined temperature. A heating cycle is delayed by a special refrigeration cycle which increases the load on the prime mover, when the temperature of the liquid coolant is not above the predetermined temperature. In a preferred embodiment of the invention, the special refrigeration cycle provides simultaneous heating and cooling cycles, which include evaporating liquid refrigerant in an evaporator associated with the conditioned space, as in a cooling cycle, while condensing hot gas refrigerant from the compressor in a condenser associated with the conditioned space, as in a heating cycle.
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Citations
18 Claims
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1. A method of operating a refrigeration unit having a compressor driven by a liquid cooled prime mover, and an economizer cycle which enhances cooling and heating cycles initiated to control the temperature of a conditioned space to a predetermined set point temperature, with the enhancing of the heating cycle including adding heat to the economizer cycle from liquid used to cool the prime mover, comprising the steps of:
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sensing the temperature of the liquid which cools the prime mover, initiating a heating cycle when required, when the sensing step detects the temperature of the liquid is above a predetermined value, and initiating a special refrigeration cycle when a heating cycle is required, prior to the step of initiating the heating cycle, when the sensing step detects the temperature is not above the predetermined value, said step of initiating the special cycle including the step of increasing the load on the prime mover, at least until the sensing step detects that the temperature of the liquid is above the predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A refrigeration unit having a compressor driven by a prime mover cooled by a liquid coolant;
- temperature sensing means for sensing the temperature of the liquid coolant;
control means for selectively configuring refrigerant flow paths of the refrigeration unit to provide heating and cooling cycles, as required to control the temperature of a conditioned space to a predetermined set point temperature; and
economizer heat exchanger means having means for adding heat to the heating cycle from the liquid coolant, characterized by;said control means immediately configuring the refrigeration flow paths to initiate a heating cycle, when required, when the temperature sensing means detects that the temperature of the liquid coolant is above a predetermined value, said control means configuring the refrigerant flow paths to provide a predetermined special refrigerant flow path which increases the load on the prime mover above that provided by the heating cycle, when a heating cycle is required and the temperature sensing means detects the temperature of the liquid coolant is not above the predetermined value, to heat the liquid coolant above the predetermined temperature before initiating a heating cycle. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
- temperature sensing means for sensing the temperature of the liquid coolant;
Specification