INDUSTRIAL RESOURCES, INC. A TRAINING SERVICES …

1 YORK CHILLERS. SYSTEM DESCRIPTION (IRI-CH-25). INDUSTRIAL RESOURCES, INC. A TRAINING SERVICES COMPANY. This document is the property of INDUSTRIAL Resources, Inc. Copies and distribution of this document is prohibited unless written authorization is granted by INDUSTRIAL Resources, Inc. Chillers (IRI-CH-25). PREFACE. The TRAINING System Description (SD) has been designed to assist you in meeting the requirements of Module (IRI-CH-25) of Power Plant Operations; it contains information about the York Chillers used in Chiller. This includes the function and details about the York Chiller components and their operation, the purpose of which is to instruct the employees on the purpose and components of the York Chillers, and how to operate the system in a safe manner.

2 You should review each chapter objective. In doing so you will be better prepared to learn the required information. You should also inspect the equipment, identifying its components and characteristics. Should you have additional question about the equipment, ask your supervisor. A separate document, York Chillers Procedure (IRI-CH-25-SOP), covers detailed procedures to be observed with regard to the York Chillers. Page 1. Chillers (IRI-CH-25). YORK CHILLERS. TRAINING DESCRIPTION. TABLE OF CONTENTS. Introduction .. 4. Function .. 4. Basic System Description .. 4. System Major Components .. 6. Compressor .. 7. Compressor Data .. 15. Compressor Controls .. 15. Condenser .. 16. Condenser Data .. 18. Condenser Controls .. 19. Intercooler .. 19. Intercooler Data.

3 21. Intercooler Control .. 21. Evaporator .. 21. System Operation .. 23. System Startup .. 24. Normal Operation .. 24. System 24. Page 2. Chillers (IRI-CH-25). List of Figures: Figure 1 Compressor Figure 2 Compressor Lubrication System Figure 3 York Compressor Cross Section Diagram Figure 4 Control Panel Figure 5 Condenser and Intercooler Figure 6 Intercooler Figure 7 Evaporator List of Drawings Drawing 1 York Chiller Refrigerant Flow Path Drawing 2 Chiller Components Page 3. Chillers (IRI-CH-25). Introduction Chapter Objectives: Describe the functions of the York Chillers. 1. State from memory the functions of the York Chillers. 2. Describe how the York Chillers operate, and where they are located, used and maintained. 3. List the normal operating parameters of the York Chillers.

4 Function The York Chillers provide chilled water for campus air conditioning and other cooling purposes. Basic System Description The York OM Titan Chillers are manufactured by Johnson Controls. The four chiller stations are equipped with a total of 11 chillers ranging from 3,000 to 5,000-ton capacity. Each York Chiller consists of a compressor, evaporator, condenser, and intercooler. The chillers are powered either by steam or electricity. The total chiller capacity for the campus is 45,000 tons. York Chiller Parameters STATION CHILLER CHARGE (lbs.) CAPACITY. Chiller Station 3 16,232 5,000. 13,000 3,000. 13,000 3,000. Chiller Station 4 0 Inoperable 13,000 3,000. 13,000 3,000. Chiller Station 5 15,922 4,000. 15,922 4,000. 16,232 5,000. Page 4. Chillers (IRI-CH-25).

5 Chiller Station 6 18,237 5,000. 18,237 5,000. 18,237 5,000. System Flow Path Drawing 1 illustrates the flow path through a York Chiller. Four systems support the chillers: cooling towers, condenser, chilled water, and refrigerant gas flows. The Condenser Water Pump draws condenser water from the cooling tower basin. Discharge from the Condenser Water Pump goes to the Condenser (tube side). The condenser water absorbs heat from the high-pressure refrigerant gas (shell side) in the condenser. The heated condenser water is then returned to the cooling towers. The Compressor compresses refrigerant gas and pushed the high-pressure gas into the Condenser (shell side). As the gas condenses, the refrigerant is passed through the Intercooler to the Evaporator (shell side).

6 The refrigerant exits the top of the Evaporator and is returned to the Compressor. Chilled water is pumped by the Chilled Water Pump through the Evaporator (tube side) where the water is cooled and then pumped to the chilled water distribution headers. If the water level falls below a set limit in the cooling tower basin, makeup water is added from the domestic water supply. Chemical injection is also available for the condensate water and chilled water. Page 5. Chillers (IRI-CH-25). Drawing 1 York Chiller Refrigerant Flow Path System Major Components Chapter Objectives: 1. Describe how each York Chiller system component operates. 2. Describe from memory, the operating parameters of the system. 3. State from memory, the names and purposes of the major components of the York Chiller.

7 4. Describe the locations of the York Chiller system components. 5. Describe how and from where the York Chiller is controlled. Page 6. Chillers (IRI-CH-25). The following major components of the York Chiller are described in this chapter: Compressor Condenser Intercooler Evaporator Drawing 2 Chiller Components Compressor The York Compressors in the chiller stations are multistage compressors (Figure 1) with a capacity of 3,000 to 5,000 tons. Compressors in the chiller stations are driven by Variable Frequency Drives (VFD) motor, electric drivers, or steam turbines. Page 7. Chillers (IRI-CH-25). Figure 1 - Compressor The Compressor has an internal labyrinth seal (Figure 2), balance piston and oil seals, shaft seals, and pre-rotation vanes, which guide the suction flow path.

8 The Compressor also has a dedicated lubrication system. The labyrinth seal prevents gas leakage between the stages. Leakage is kept to a minimum by means of labyrinths mounted between the diffuser plates and the rotating shaft. The close radial clearance between the labyrinths and rotator shaft reduces gas leakage along the shaft. Due to the pressure difference between the suction and discharge of the compressor, the compressor is equipped with a balance piston. The balance piston is located behind the second stage impeller to counteract the differential pressure. By subjecting the outboard side of the Page 8. Chillers (IRI-CH-25). balance piston to low pressure from the inlet side of the compressor, a pressure differential is created in the opposite direction of the impellers.

9 Any impeller thrust that is not balanced by the balance piston is absorbed by the thrust bearing. The balance piston seal prevents leakage from the high stage impeller along the balance piston. Leakage at the balance piston is minimized by the balance piston seal ring. The balance piston seal ring assembly consists of a floating seal ring and spring in the balance piston cover. Close clearance between the floating ring and rotating balance piston reduces gas leakage to a minimum. Oil leakage from the main bearings into the impellers is prevented by oil seals located on the rotor shaft inboard from the main bearings. The oil seals permit a slight gas leakage into the lubricating system that opposes and prevents oil leakage. The front seal is pressurized by a shaft hole from the second stage inlet while the balance piston pressurizes the rear seal.

10 The shaft seal prevents gas leakage along the shaft to the atmosphere by means of a spring- loaded mechanical seal assembly. The shaft seal assembly consists of a rotating cast iron shaft seal collar with an O-ring and spring-loaded carbon shaft seal ring assembly (12 helical springs and O-rings). The helical springs in the shaft seal ring assembly keep the carbon seal ring in contact with the rotating shaft seal collar. The rotating collar is driven by pins and turns with the shaft. The stationery carbon seal assembly is mounted on the shaft seal cover and is prevented from rotating by keys. The friction surface between the rotating collar and stationery carbon seal assembly is lubricated and cooled by oil circulated through the seal cavity. The compressor Pre-Rotation Vanes (PRVs) are internal guide vanes in the suction flow path to the first stage impeller wheel.