Reciprocating compressor with heat exchanger having thermal storage media
A reciprocating compressor comprises a gas inlet section including an inlet gas meter for metering inlet gas from a high pressure storage vessel, a compressor, a valve control panel and storage, a pressure let down that depressurizes the high pressure gas from the high pressure storage vessel to the inlet of the compressor section, a heat exchanger having thermal storage media, and a dispenser.
1. A system, comprising:
a gas inlet section including an inlet gas meter for metering inlet gas from a high pressure storage vessel;
a compressor;
a valve control panel and storage;
a pressure let down that depressurizes the high pressure gas from the high pressure storage vessel to the inlet of the compressor section;
a heat exchanger having thermal storage media; and
a dispenser;
wherein the pressure let down section draws the gas from the high pressure vessel at a pressure from 3600 psig to 4500 psig down to a pressure of 20 psig to 200 psig before it enters the compressor.
2. The system of claim 1 , wherein the thermal storage media comprises a water or glycol solution whose temperature is lowered by the heat exchanger.
3. The system of claim 1 , wherein during use of the heat exchanger, heat from the thermal storage media is added to the gas, thereby cooling the thermal storage media to a low temperature state.
4. The system of claim 1 , wherein the low temperature storage media is employed for active temperature conditioning.
5. The system of claim 4 , wherein electronic temperature conditioning is achieved by using a sensor to detect a temperature of the gas and using the low temperature thermal storage media in the heat exchanger to lower the temperature of the dispensing gas before being dispensed by the dispenser.
6. The system of claim 5 , wherein the sensor comprises a thermocouple or an RTD.
7. The system of claim 1 , wherein by supplementing the inlet gas with a pressure let down in order to de-pressurize the gas from the high-pressure storage vessel, a CNG station has the ability to increase and adjust its flow capacity.
8. The system of claim 1 , wherein the valve control panel and storage comprises a series of control valves that direct the flow of gas among the compressor, the heat exchanger, local storage vessels, and the dispenser.
9. A method for refueling a motor vehicle, the method comprising:
metering inlet gas from a high pressure storage vessel;
depressurizing high pressure gas from the high pressure storage vessel to an inlet of a compressor;
passing the de-pressurized gas through a heat exchanger having thermal storage media, thereby cooling the thermal media to a low temperature state; and
dispensing the gas;
wherein the pressure let down section draws the gas from the high pressure vessel at a pressure from 3600 psig to 4500 psig down to a pressure of 20 psig to 200 psig before it enters the compressor.
10. The method of claim 9 , further comprising using electronic gas temperature monitoring to direct some or all of the dispensing gas going to the dispenser through the low temperature thermal media to condition the temperature of the gas to a predetermined temperature or temperature range.
11. The method of claim 10 , wherein using electronic gas temperature monitoring comprises using a sensor to detect a temperature of the gas and using the low temperature thermal storage media in the heat exchanger to lower the temperature of the dispensing gas before dispensing the gas.
12. The method of claim 9 , wherein depressurizing high pressure gas comprises supplementing the inlet gas with a pressure let down in order to depressurize the gas from the high-pressure storage vessel, whereby a CNG station has the ability to increase and adjust its flow capacity.
13. The method of claim 9 , further comprising directing the flow of gas from the compressor to the heat exchanger, local storage vessels or to a dispensing section for dispensing the gas.
14. The method of claim 9 , wherein the pressure let down section allows the compressor to operate at a high flow capacity during peak hours.
15. The method of claim 14 , wherein the pressure let down section allows the compressor to draw in gas from a local gas utility and refill the high pressure storage vessels at a slower flow capacity and at a lower power level during non-peak hours.