Method primarily for performance control at heat pumps or refrigerating installations and arrangement for carrying out the method

• US 4,611,470 A
• Filed: 10/18/1984
• Issued: 09/16/1986
• Est. Priority Date: 06/02/1983
• Status: Expired due to Fees

• Current Assignee: Henrik S. Enstrom
• Original Assignee: Henrik S. Enstrom
• Inventors: Enstrom, Henrik S.
• Primary Examiner(s): Tanner, Harry
• Application Number:
  US06/662,031
• Time in Patent Office: 698 Days
• Field of Search: 62/125, 62/126, 62/127, 62/129, 62/130, 236/94, 165/11 R, 364/551, 364/557, 364/418, 73/112
• US Class Current: 62/127
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems
• CPC Class Codes: G01L 3/26 Devices for measuring efficiency, i.e. the ratio of power output to power input
• CPC Class Codes: G01M 13/00 Testing of machine parts
• CPC Class Codes: G05D 23/1917 using digital means

Abstract

A method of primarily testing and performance controlling heat pumps, refrigerating installations or corresponding systems, at which system thermal energy from at least one heat source (K) is supplied to an energy-carrying medium (1), a refrigerant, which circulates in the system and is advanced therein by at least one, preferably electrically driven compressor (2) and is caused to pass through at least one condenser (VVX) where thermal energy is emitted and exchanged to a thermal energy carrying medium, a thermal sink, where the control comprises the determining of real performance, such as thermal output (Q₁) and so-called coefficient of performance (COP) against the background of measurements. The method is especially characterized in that performance, such as thermal output (Q₁,f) or refrigerating output (Q₁,f) and coefficient of thermal performance (COP_f) or coefficient of refrigerating performance (ε_f), expected against the background of actual operation conditions is determined preferably automatically and continuously and compared automatically to corresponding real performance (Q₁, COP, ε) based on measurements. The invention also relates to an arrangement for carrying out the method.

Claims

1. A method of primarily testing and performance control of heat pumps, refrigerating installations or corresponding systems, in which system thermal energy from at least one heat source is supplied to an energy-carrying medium such as a refrigerant, which circulates in the system and is advanced therein by at least one compressor and caused to pass through at least one condenser where thermal energy is emitted and exchanged to an energy-carrying medium such as a thermal sink, where the method includes the steps of determining actual values in the form of real performance of such parameters as thermal output and so-called coefficient of performance, against the background of measurements, and automatically and substantially continuously comparing said real performance values to nominal, ideal values representing corresponding expected performance values, characterized by the steps of determining said expected performance values, such as thermal output or refrigerating output (Q₁,f) and coefficient of thermal performance COP₁) or coefficient of refrigerating performance (ε

_f), automatically and substantially continuously based on actual operating conditions, which are substantially continuously determined by means of measurements.

2. A method as defined in claim 1, wherein said measurements include measuring parameters related to the heat source(s) (K), such as the temperature (T_k,T_k,ut), flow (V_k) and, at air, the relative humidity (RF_k) of its/their energy-carrying medium, and parameters relating to the thermal energy carrier(s), such as the temperature before (T_s) and after (T_s,ut) exchange, the flow (V_s) and, at air, the relative humidity (RF_s), and relating to the compressor(s) (2), such as electric energy input (E_k) and, said measurements being determined and transferred to a central unit (CE), which contains information on expected performance under different operation conditions, and which automatically determines expected performance corresponding to certain of said measurement results relating to operation conditions and compares the same to real performance, which is determined on the basis of certain of said the measurement results, such as electric energy input and temperature before and after exchange and flow concerning the thermal energy carrier.

3. A method as defined in claim 1, wherein only certain of the parameter values required for the determination of expected and real performance are measured or determined continuously, and further characterized in that remaining values are pre-determined, for example empirically, and processed as constants at the performance determination.

4. A method as defined in claim 3 wherein the heat source is spent air from a residential building or the like, and the thermal energy carrier is tap hot water or the like, and further characterized in that the temperature (T_s,T_s,ut) and the flow (V_s) of the thermal energy carrier are measured, and thermal output (Q₁) and electric power input (E_k) are determined.

5. A method as defined in claim 3, further characterized in that the temperature (T_k,T_k,ut) of the energy-carrying medium of the heat source(s) (K) and the temperature (T_s,T_s,ut) of the thermal energy carrier(s) are measured, and functions for the determination of real thermal output (Q₁) and electric power input (E_k) are pre-determined empirically.

6. A method as defined in claim 3 wherein the heat source is spent air from a residential building or the like and/or exterior air, and the system preferably includes both tap hot water and radiator hot water as thermal energy carriers, and further characterized in that the temperature of the respective thermal energy carrier before (T_s1,T_s2) and after (T_s1,ut,T_s2,ut) heat exchange and the flow (V_s1,V_s2) of the respective thermal energy carrier are measured, that the heat amount emitted is measured by heat volume indicators, and that the measurement results or the like are taken up for the compressor(s) concerning power input (E_k) and capacity control adjustment (N_k) and for the air concerning its temperature (T_k) before heat exchange and for the fan(s) (16) provided for the advancing of air concerning capacity control adjustment.

7. A method as defined in claim 3 wherein heat is taken from a heat source in liquid state, and the method includes providing both tap hot water and radiator hot water as thermal energy carrier, and is further characterized by the steps of measuring the temperature of the respective thermal energy carrier before (T_s1,T_s2) and after (T_s1,ut,T_s2,ut) heat exchange, measuring the flow (V_s1,V_s2) of the respective thermal energy carrier, measuring the heat amount emitted by heat volume indicators, and taking the measurement results for the compressor(s) (2) concerning power input (E_k) and capacity control adjustment (N_k) and for the liquid concerning its temperature before (T_k) and/or after (T_k,ut) heat exchange or for the heat source (T_k), from which heat is taken by means of the refrigerant.

8. A method as defined in claim 2, further characterized in that the magnitudes, on the basis of which the operation of the system is controlled according to the existing control equipment of the system, are measured, and that determination automatically and substantially continuously is carried out whether the installation is operative and, if the installation is not operative, whether the installation is not expected to be operative against the background of the actual measurement results.

9. A method as defined in claim 8, further characterized in that time checking is started when it is determined that the installation is not operative although it is expected to be operative, which time checking goes on until the installation starts or the operation conditions are changed so that operation is not expected, whereby unexpected downtime is registered.

10. A method as defined in claim 1, further characterized in that real performance achieved when the system operates in the way intended is registered and used as expected performance.

11. A method as defined in claim 1, further characterized in that an alarm signal (14) is given when the difference between real performance and expected performance amounts to a pre-determined magnitude and/or when during a certain longer time a clear trend concerning continuous deterioration of real performance compared to expected performance has been registered.

12. An arrangement for primarily testing and performance control at heat pumps or refrigerating installations, where the system comprises an energy-carrying medium such as a refrigerant, which circulates in the system and is intended to be advanced in the system by at least one compressor and at least one evaporator, at which thermal energy from a heat source is intended to be transferred to said energy-carrying medium, and at least one condenser, at which thermal energy is intended to be emitted by said energy-carrying medium to a second thermal energy carrying medium such as a thermal sink, the system including means (3-11,15) for automatically determining the actual operating conditions in the form of measurement results and for automatically determining measurement results for determining actual values in the form of real performance, such as thermal output (Q₁,f) or refrigerating output (Q₁,f) and so-called coefficient of thermal performance (COP_f) or coefficient of refrigerating performance (ε

_f), on the basis of said measurement results, means for automatically and substantially continuously comparing said actual values and nominal, ideal values in the form of corresponding expected performance;

characterized by means for automatically and continuously determining said expected performance on the basis of said measurement results for said actual operating conditions.

13. An arrangement as defined in claim 12, further characterized by means for determining measurement results pertaining to the heat-source(s) (K), such as the temperature (T_k,T_k,ut) and flow (V_k) and, at air, the relative humidity (RF_k) of its/their thermal energy carrying medium, and measurement results pertaining to the thermal energy carrier(s), such as the temperature before (T_s) and after (T_s,ut) heat exchange, the flow (V_s) and, at air, the relative humidity (RF_s), and measurement results characterizing the compressor(s) (2), such as electric energy input (E_k) and, which measurement results are intended in the form of signals to be transferred to a central unit (CE) or the like, which preferably comprises a microcomputer, and which contains information on expected performance, such as thermal output (Q₁,f) and electric power input (E_k,f) as a function of some of said measurement results, and which unit (CE) is capable, substantially continuously and the basis of these certain measurement results, to produce expected performance, and on the basis of measurement results for the calculation of real performance substantially continuously to determine real performance (Q₁,COP) and substantially continuously to compare definite expected and real performance corresponding to each other.

14. An arrangement as defined in claim 12, including means for continuously determining only certain of the parameter values required for the determination of real and expected performance, and further characterized in that the remaining parameter values required for said performance determination exist, for example empirically, pre-determined and stored as constants in the central unit or the like.

15. An arrangement as defined in claim 14 wherein said heat source is spent air from a residential building or the like and the thermal energy carrier is tap hot water or the like, and further characterized by means (3,4,7,8,10,12,13) for substantially continuously determining the temperature (T_s,T_s,ut) and flow (V_s) of the thermal energy carrier and thermal output (Q₁) and electric power input (E_k).

16. An arrangement as defined in claim 14, further characterized by means (3,4,7,8) for substantially continuously determining the temperature (T_k,T_k,ut) of the energy-carrying medium of the heat source(s) (K) and the temperature (T_s,T_s,ut) of the thermal energy carrier(s), and the central unit (CE) contains empirically pre-determined functions for determining real thermal output (Q₁) and electrical power input on the basis of said temperatures (T_k,T_k,ut,T_s,T_s,ut).

17. An arrangement as defined in claim 14 wherein the heat source is spent air from a residential building and/or exterior air, and where the system includes both tap hot water and radiator hot water as thermal energy carrier, and further characterized in that it comprises means (7,8,10) for determining the temperature of the respective thermal energy carrier before (T_s1,T_s2) and after (T_s1,ut,T_s2,ut) heat exchange, and the flow (V_s1,V_s2) of the respective thermal energy carrier, and heat volume indicators (13) are provided for determining thermal output (Q_s1,Q_s2), and that it includes means (12,11,3,15) for determining the measurement results for the compressor(s) (2) concerning power input (E_k) and capacity control adjustment (N_k) and for the air concerning its temperature (T_k) before heat exchange and for the fan(s) (16) provided for advancing the air concerning capacity control adjustment (N_F).

18. An arrangement as defined in claim 14 wherein heat is intended to be taken from a heat source in liquid state, to which heat from water is intended to be exchanged, and where the system includes both tap hot water and radiator water as thermal energy carrier, and further characterized in that it includes means (7,8,10) for determining the temperature of the respective thermal energy carrier before (T_s1,T_s2) and after (T_s1,ut,T_s2,ut) heat exchange, and the flow (V_s1,V_s2) of the respective thermal energy carrier, and heat volume indicators (13) are provided for determining thermal output (Q_s1,Q_s2), and that it includes means (12,11,3,4) for determining the measurement results or the like for the compressor(s) (2) concerning power input (E_k) and capacity control adjustment (N_k) and for the liquid concerning its temperature before (T_k) and/or after (T_k,ut) heat exchange.

19. An arrangement as defined in claim 14 further characterized in that it includes means for measuring the magnitudes, on the basis of which the operation of the installation is controlled according to the existing control equipment of the system, and that it includes means such as a central unit for automatically and substantially continuously determining whether the installation is operative, and when the installation is not operative, whether the installation is not expected to be opertive against the background of the actual measurement results.

20. An arrangement as defined in claim 19, further characterized in that it includes means for time checking capable to start when it is determined that the system is not operative although it is expected to be operative, which time checking is intended to go on until the installation starts or the operation conditions are changed so that operation is not expected, whereby unexpected downtime can be registered.

21. An arrangement as defined in claim 12, further characterized in that said central unit (CE) is capable of registering definite real performance achieved when the system operates in the way intended, and of utilizing performance thus registered as expected performance at said comparison.

22. An arrangement as defined in claim 12, further characterized in that said central unit (CE) is capable, at a predetermined difference between expected and real performance and/or when during a certain longer time a clear trend concerning continuous deterioration of real performance compared to expected performance has been registered, of initiating an alarm by means of an acoustic signal (14) or an optic signal.